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Sample records for fine chemical production

  1. The production of fine chemicals by biotransformations.

    PubMed

    Straathof, Adrie J J; Panke, Sven; Schmid, Andreas

    2002-12-01

    Today, biocatalysis is a standard technology for the production of chemicals. An analysis of 134 industrial biotransformations reveals that hydrolases (44%) and redox biocatalysts (30%) are the most prominent categories. Most products are chiral (89%) and are used as fine chemicals. In the chemical industry, successful product developments involve on average a yield of 78%, a volumetric productivity of 15.5 g/(L.h) and a final product concentration of 108 g/L. By contrast, the pharmaceutical industry focuses on time-to-market. The implications of this for future research and development on biocatalysis are discussed.

  2. Yeast cell factories for fine chemical and API production

    PubMed Central

    Pscheidt, Beate; Glieder, Anton

    2008-01-01

    This review gives an overview of different yeast strains and enzyme classes involved in yeast whole-cell biotransformations. A focus was put on the synthesis of compounds for fine chemical and API (= active pharmaceutical ingredient) production employing single or only few-step enzymatic reactions. Accounting for recent success stories in metabolic engineering, the construction and use of synthetic pathways was also highlighted. Examples from academia and industry and advances in the field of designed yeast strain construction demonstrate the broad significance of yeast whole-cell applications. In addition to Saccharomyces cerevisiae, alternative yeast whole-cell biocatalysts are discussed such as Candida sp., Cryptococcus sp., Geotrichum sp., Issatchenkia sp., Kloeckera sp., Kluyveromyces sp., Pichia sp. (including Hansenula polymorpha = P. angusta), Rhodotorula sp., Rhodosporidium sp., alternative Saccharomyces sp., Schizosaccharomyces pombe, Torulopsis sp., Trichosporon sp., Trigonopsis variabilis, Yarrowia lipolytica and Zygosaccharomyces rouxii. PMID:18684335

  3. Yeast cell factories for fine chemical and API production.

    PubMed

    Pscheidt, Beate; Glieder, Anton

    2008-08-07

    This review gives an overview of different yeast strains and enzyme classes involved in yeast whole-cell biotransformations. A focus was put on the synthesis of compounds for fine chemical and API (= active pharmaceutical ingredient) production employing single or only few-step enzymatic reactions. Accounting for recent success stories in metabolic engineering, the construction and use of synthetic pathways was also highlighted. Examples from academia and industry and advances in the field of designed yeast strain construction demonstrate the broad significance of yeast whole-cell applications. In addition to Saccharomyces cerevisiae, alternative yeast whole-cell biocatalysts are discussed such as Candida sp., Cryptococcus sp., Geotrichum sp., Issatchenkia sp., Kloeckera sp., Kluyveromyces sp., Pichia sp. (including Hansenula polymorpha = P. angusta), Rhodotorula sp., Rhodosporidium sp., alternative Saccharomyces sp., Schizosaccharomyces pombe, Torulopsis sp., Trichosporon sp., Trigonopsis variabilis, Yarrowia lipolytica and Zygosaccharomyces rouxii.

  4. A 'Fine' chemical industry for life science products: green solutions to chemical challenges.

    PubMed

    Bruggink, A; Straathof, A J J; van der Wielen, L A M

    2003-01-01

    Modern biotechnology, in combination with chemistry and process technology, is crucial for the development of new clean and cost effective manufacturing concepts for fine-chemical, food specialty and pharmaceutical products. The impact of biocatalysis on the fine-chemicals industry is presented, where reduction of process development time, the number of reaction steps and the amount of waste generated per kg of end product are the main targets. Integration of biosynthesis and organic chemistry is seen as a key development. The advances in bioseparation technology need to keep pace with the rate of development of novel bio- or chemocatalytic process routes with revised demands on process technology. The need for novel integrated reactors is also presented. The necessary acceleration of process development and reduction of the time-to-market seem well possible, particularly by integrating high-speed experimental techniques and predictive modelling tools. This is crucial for the development of a more sustainable fine-chemicals industry. The evolution of novel 'green' production routes for semi-synthetic antibiotics (SSAs) that are replacing existing chemical processes serves as a recent and relevant case study of this ongoing integration of disciplines. We will also show some challenges in this specific field.

  5. Development of bio-based fine chemical production through synthetic bioengineering.

    PubMed

    Hara, Kiyotaka Y; Araki, Michihiro; Okai, Naoko; Wakai, Satoshi; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-12-14

    Fine chemicals that are physiologically active, such as pharmaceuticals, cosmetics, nutritional supplements, flavoring agents as well as additives for foods, feed, and fertilizer are produced by enzymatically or through microbial fermentation. The identification of enzymes that catalyze the target reaction makes possible the enzymatic synthesis of the desired fine chemical. The genes encoding these enzymes are then introduced into suitable microbial hosts that are cultured with inexpensive, naturally abundant carbon sources, and other nutrients. Metabolic engineering create efficient microbial cell factories for producing chemicals at higher yields. Molecular genetic techniques are then used to optimize metabolic pathways of genetically and metabolically well-characterized hosts. Synthetic bioengineering represents a novel approach to employ a combination of computer simulation and metabolic analysis to design artificial metabolic pathways suitable for mass production of target chemicals in host strains. In the present review, we summarize recent studies on bio-based fine chemical production and assess the potential of synthetic bioengineering for further improving their productivity.

  6. [Applications of nitrile converting enzymes in the production of fine chemicals].

    PubMed

    Zheng, Yuguo; Xue, Yaping; Liu, Zhiqiang; Zheng, Renchao; Shen, Yinchu

    2009-12-01

    Nitriles are an important type of synthetic intermediates in the production of fine chemicals because of their easy preparations and versatile transformations. The traditional chemical conversion of nitriles to carboxylic acids and amides is feasible but it requires relatively harsh conditions of heat, acid or alkali. Nitrile converting enzymes (nitrilase, nitrile hydratase and amidase) which are used as biocatalyst for the production of fine chemicals have attracted substantial interest because of their ability to convert readily available nitriles into the corresponding higher value amides or acids under mild conditions with excellent chemo-, regio- and stereo-selectivities. Many nitrile converting enzymes have been explored and widely used for the production of fine chemicals. In this paper, various examples of biocatalytic synthesis of pharmaceuticals and their intermediates, agrochemicals and their intermediates, food and feed additives, and other fine chemicals are presented. In the near future, an increasing number of novel nitrile converting enzymes will be screened and their potential in the production of useful fine chemicals will be further exploited.

  7. Impact of synthetic biology and metabolic engineering on industrial production of fine chemicals.

    PubMed

    Jullesson, David; David, Florian; Pfleger, Brian; Nielsen, Jens

    2015-11-15

    Industrial bio-processes for fine chemical production are increasingly relying on cell factories developed through metabolic engineering and synthetic biology. The use of high throughput techniques and automation for the design of cell factories, and especially platform strains, has played an important role in the transition from laboratory research to industrial production. Model organisms such as Saccharomyces cerevisiae and Escherichia coli remain widely used host strains for industrial production due to their robust and desirable traits. This review describes some of the bio-based fine chemicals that have reached the market, key metabolic engineering tools that have allowed this to happen and some of the companies that are currently utilizing these technologies for developing industrial production processes.

  8. Mapping the patent landscape of synthetic biology for fine chemical production pathways.

    PubMed

    Carbonell, Pablo; Gök, Abdullah; Shapira, Philip; Faulon, Jean-Loup

    2016-09-01

    A goal of synthetic biology bio-foundries is to innovate through an iterative design/build/test/learn pipeline. In assessing the value of new chemical production routes, the intellectual property (IP) novelty of the pathway is important. Exploratory studies can be carried using knowledge of the patent/IP landscape for synthetic biology and metabolic engineering. In this paper, we perform an assessment of pathways as potential targets for chemical production across the full catalogue of reachable chemicals in the extended metabolic space of chassis organisms, as computed by the retrosynthesis-based algorithm RetroPath. Our database for reactions processed by sequences in heterologous pathways was screened against the PatSeq database, a comprehensive collection of more than 150M sequences present in patent grants and applications. We also examine related patent families using Derwent Innovations. This large-scale computational study provides useful insights into the IP landscape of synthetic biology for fine and specialty chemicals production. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  9. SYNBIOCHEM–a SynBio foundry for the biosynthesis and sustainable production of fine and speciality chemicals

    PubMed Central

    Carbonell, Pablo; Currin, Andrew; Dunstan, Mark; Fellows, Donal; Jervis, Adrian; Rattray, Nicholas J.W.; Robinson, Christopher J.; Swainston, Neil; Vinaixa, Maria; Williams, Alan; Yan, Cunyu; Barran, Perdita; Breitling, Rainer; Chen, George Guo-Qiang; Faulon, Jean-Loup; Goble, Carole; Goodacre, Royston; Kell, Douglas B.; Feuvre, Rosalind Le; Micklefield, Jason; Scrutton, Nigel S.; Shapira, Philip; Takano, Eriko; Turner, Nicholas J.

    2016-01-01

    The Manchester Synthetic Biology Research Centre (SYNBIOCHEM) is a foundry for the biosynthesis and sustainable production of fine and speciality chemicals. The Centre's integrated technology platforms provide a unique capability to facilitate predictable engineering of microbial bio-factories for chemicals production. An overview of these capabilities is described. PMID:27284023

  10. SYNBIOCHEM-a SynBio foundry for the biosynthesis and sustainable production of fine and speciality chemicals.

    PubMed

    Carbonell, Pablo; Currin, Andrew; Dunstan, Mark; Fellows, Donal; Jervis, Adrian; Rattray, Nicholas J W; Robinson, Christopher J; Swainston, Neil; Vinaixa, Maria; Williams, Alan; Yan, Cunyu; Barran, Perdita; Breitling, Rainer; Chen, George Guo-Qiang; Faulon, Jean-Loup; Goble, Carole; Goodacre, Royston; Kell, Douglas B; Feuvre, Rosalind Le; Micklefield, Jason; Scrutton, Nigel S; Shapira, Philip; Takano, Eriko; Turner, Nicholas J

    2016-06-15

    The Manchester Synthetic Biology Research Centre (SYNBIOCHEM) is a foundry for the biosynthesis and sustainable production of fine and speciality chemicals. The Centre's integrated technology platforms provide a unique capability to facilitate predictable engineering of microbial bio-factories for chemicals production. An overview of these capabilities is described.

  11. Metabolism of fluoroorganic compounds in microorganisms: impacts for the environment and the production of fine chemicals.

    PubMed

    Murphy, Cormac D; Clark, Benjamin R; Amadio, Jessica

    2009-09-01

    Incorporation of fluorine into an organic compound can favourably alter its physicochemical properties with respect to biological activity, stability and lipophilicity. Accordingly, this element is found in many pharmaceutical and industrial chemicals. Organofluorine compounds are accepted as substrates by many enzymes, and the interactions of microorganisms with these compounds are of relevance to the environment and the fine chemicals industry. On the one hand, the microbial transformation of organofluorines can lead to the generation of toxic compounds that are of environmental concern, yet similar biotransformations can yield difficult-to-synthesise products and intermediates, in particular derivatives of biologically active secondary metabolites. In this paper, we review the historical and recent developments of organofluorine biotransformation in microorganisms and highlight the possibility of using microbes as models of fluorinated drug metabolism in mammals.

  12. Trends and innovations in industrial biocatalysis for the production of fine chemicals.

    PubMed

    Panke, Sven; Held, Martin; Wubbolts, Marcel

    2004-08-01

    Biocatalysis has become an established technology for the industrial manufacture of fine chemicals. In recent years, a multitude of chemical companies have embraced biocatalysis for the manufacture of desired stereoisomers, and new or improved methods for the synthesis of enantiomerically pure alpha- and beta-amino acids, amines, amides, peptides, nitriles, alcohols, organic acids and epoxides have emerged. Furthermore, the selectivity and mild operational conditions of biocatalysts are increasingly applied in industry to modify complex target molecules. These recent innovations in the manufacture of industrial fine chemicals using biocatalysis are discussed from an industrial perspective.

  13. Methyl ricinoleate as platform chemical for simultaneous production of fine chemicals and polymer precursors.

    PubMed

    Dupé, Antoine; Achard, Mathieu; Fischmeister, Cédric; Bruneau, Christian

    2012-11-01

    The modification of methyl ricinoleate by etherification of the hydroxyl group was accomplished by using a nonclassical ruthenium-catalyzed allylation reaction and also by esterification. Methyl ricinoleate derivatives were engaged in ring-closing metathesis (RCM) reactions leading to biosourced 3,6-dihydropyran and α,β-unsaturated lactone derivatives with concomitant production of polymer precursors. Sequential RCM/hydrogenation and RCM/cross-metathesis were also implemented as a straightforward method for the synthesis of tetrahydropyran and lactone derivatives as well as valuable monomers (i.e., polyamide precursors).

  14. Integrated operation of continuous chromatography and biotransformations for the generic high yield production of fine chemicals.

    PubMed

    Bechtold, Matthias; Makart, Stefan; Heinemann, Matthias; Panke, Sven

    2006-06-25

    The rapid progress in biocatalysis in the identification and development of enzymes over the last decade has enormously enlarged the chemical reaction space that can be addressed not only in research applications, but also on industrial scale. This enables us to consider even those groups of reactions that are very promising from a synthetic point of view, but suffer from drawbacks on process level, such as an unfavourable position of the reaction equilibrium. Prominent examples stem from the aldolase-catalyzed enantioselective carbon-carbon bond forming reactions, reactions catalyzed by isomerising enzymes, and reactions that are kinetically controlled. On the other hand, continuous chromatography concepts such as the simulating moving bed technology have matured and are increasingly realized on industrial scale for the efficient separation of difficult compound mixtures - including enantiomers - with unprecedented efficiency. We propose that coupling of enzyme reactor and continuous chromatography is a very suitable and potentially generic process concept to address the thermodynamic limitations of a host of promising biotransformations. This way, it should be possible to establish novel in situ product recovery processes of unprecedented efficiency and selectivity that represent a feasible way to recruit novel biocatalysts to the industrial portfolio.

  15. Enhanced benzaldehyde tolerance in Zymomonas mobilis biofilms and the potential of biofilm applications in fine-chemical production.

    PubMed

    Li, Xuan Zhong; Webb, Jeremy S; Kjelleberg, Staffan; Rosche, Bettina

    2006-02-01

    Biotransformation plays an increasingly important role in the industrial production of fine chemicals due to its high product specificity and low energy requirement. One challenge in biotransformation is the toxicity of substrates and/or products to biocatalytic microorganisms and enzymes. Biofilms are known for their enhanced tolerance of hostile environments compared to planktonic free-living cells. Zymomonas mobilis was used in this study as a model organism to examine the potential of surface-associated biofilms for biotransformation of chemicals into value-added products. Z. mobilis formed a biofilm with a complex three-dimensional architecture comprised of microcolonies with an average thickness of 20 microm, interspersed with water channels. Microscopic analysis and metabolic activity studies revealed that Z. mobilis biofilm cells were more tolerant to the toxic substrate benzaldehyde than planktonic cells were. When exposed to 50 mM benzaldehyde for 1 h, biofilm cells exhibited an average of 45% residual metabolic activity, while planktonic cells were completely inactivated. Three hours of exposure to 30 mM benzaldehyde resulted in sixfold-higher residual metabolic activity in biofilm cells than in planktonic cells. Cells inactivated by benzaldehyde were evenly distributed throughout the biofilm, indicating that the resistance mechanism was different from mass transfer limitation. We also found that enhanced tolerance to benzaldehyde was not due to the conversion of benzaldehyde into less toxic compounds. In the presence of glucose, Z. mobilis biofilms in continuous cultures transformed 10 mM benzaldehyde into benzyl alcohol at a steady rate of 8.11 g (g dry weight)(-1) day(-1) with a 90% molar yield over a 45-h production period.

  16. Enhanced Benzaldehyde Tolerance in Zymomonas mobilis Biofilms and the Potential of Biofilm Applications in Fine-Chemical Production

    PubMed Central

    Li, Xuan Zhong; Webb, Jeremy S.; Kjelleberg, Staffan; Rosche, Bettina

    2006-01-01

    Biotransformation plays an increasingly important role in the industrial production of fine chemicals due to its high product specificity and low energy requirement. One challenge in biotransformation is the toxicity of substrates and/or products to biocatalytic microorganisms and enzymes. Biofilms are known for their enhanced tolerance of hostile environments compared to planktonic free-living cells. Zymomonas mobilis was used in this study as a model organism to examine the potential of surface-associated biofilms for biotransformation of chemicals into value-added products. Z. mobilis formed a biofilm with a complex three-dimensional architecture comprised of microcolonies with an average thickness of 20 μm, interspersed with water channels. Microscopic analysis and metabolic activity studies revealed that Z. mobilis biofilm cells were more tolerant to the toxic substrate benzaldehyde than planktonic cells were. When exposed to 50 mM benzaldehyde for 1 h, biofilm cells exhibited an average of 45% residual metabolic activity, while planktonic cells were completely inactivated. Three hours of exposure to 30 mM benzaldehyde resulted in sixfold-higher residual metabolic activity in biofilm cells than in planktonic cells. Cells inactivated by benzaldehyde were evenly distributed throughout the biofilm, indicating that the resistance mechanism was different from mass transfer limitation. We also found that enhanced tolerance to benzaldehyde was not due to the conversion of benzaldehyde into less toxic compounds. In the presence of glucose, Z. mobilis biofilms in continuous cultures transformed 10 mM benzaldehyde into benzyl alcohol at a steady rate of 8.11 g (g dry weight)−1 day−1 with a 90% molar yield over a 45-h production period. PMID:16461720

  17. An Alkane-Responsive Expression System for the Production of Fine Chemicals

    PubMed Central

    Panke, Sven; Meyer, Andreas; Huber, Caroline M.; Witholt, Bernard; Wubbolts, Marcel G.

    1999-01-01

    Membrane-located monooxygenase systems, such as the Pseudomonas putida mt-2-derived xylene oxygenase, are attractive for challenging transformations of apolar compounds, including enantiospecific epoxidations, but are difficult to synthesize at levels that are useful for application to biotechnological processes. In order to construct efficient biocatalysis strains, we utilized the alkane-responsive regulatory system of the OCT plasmid-located alk genes of Pseudomonas oleovorans GPo1, a very attractive system for recombinant biotransformation processes. Determination of the nucleotide sequence of alkS, whose activated gene product positively regulates the transcription of the structural genes alkBFGHJKL, on a 3.7-kb SalI-HpaI OCT plasmid fragment was completed, and the N-terminal amino acid sequence of an AlkS-LacZ fusion protein was found to be consistent with the predicted DNA sequence. The alkS gene and the alkBp promoter were assembled into a convenient alkane-responsive genetic expression cassette which allowed expression of the xylene oxygenase genes in a recombinant Escherichia coli strain at a specific activity of 91 U per g (dry weight) of cells when styrene was the substrate. This biocatalyst was used to produce (S)-styrene oxide in two-liquid-phase cultures. Volumetric productivities of more than 2 g of styrene oxide per h per liter of aqueous phase were obtained; these values represented a fivefold improvement compared with previous results. PMID:10347009

  18. Direct micellar systems as a tool to improve the efficiency of aromatic substrate conversion for fine chemicals production.

    PubMed

    Berti, D; Randazzo, D; Briganti, F; Baglioni, P; Scozzafava, A; Di Gennaro, P; Galli, E; Bestetti, G

    2000-04-01

    Whole-cell bioconversion of naphthalene to (+)-cis-(1R,2S)-dihydroxy-1,2-dihydronaphthalene by Escherichia coli JM109(pPS1778) recombinant strain, carrying naphthalene dioxygenase and regulatory genes cloned from Pseudomonas fluorescens N3, in direct micellar systems is optimized as an example of fine chemicals bioproduction from scarcely water-soluble substrates. The oxygen insertion into the aromatic substrate, which stops at the enantiomerically pure cis dihydroxylated product, is performed in direct microemulsion systems, where a non-ionic surfactant stabilizes naphthalene containing oil droplets in an aqueous medium. These media provide an increased substrate solubility so that a homogeneous reaction can be carried out, while not affecting bacteria viability and performances. The influence of the chemical nature of the oil is investigated. The phase behavior of the direct microemulsion system was monitored for three different oils as a function their volume fraction and characterized through light scattering. The addition of isopropyl palmitate, oleic acid, or glyceryl trioleate, 0.6-1.2% v/v to the micellar systems, led to an increase of the substrate concentration in the solution and particularly its bioavailability, allowing faster catalytic conversions. All these systems resulted in being suitable for catalytic conversions of aromatic compounds. Although the nature of the oil does have a deep effect on the phase behavior of the micellar systems, in the present investigation no differences in the yields and in the rates of product formation of the enzymatic system were observed on changing the oil, thus showing that in this case the substrate concentration or bioavailability is not the rate-limiting step.

  19. Chemical composition of Martian fines

    NASA Technical Reports Server (NTRS)

    Clark, B. C.; Baird, A. K.; Weldon, R. J.; Tsusaki, D. M.; Schnabel, L.; Candelaria, M. P.

    1982-01-01

    Of the 21 samples acquired for the Viking X-ray fluorescence spectrometer, 17 were analyzed to high precision. Compared to typical terrestrial continental soils and lunar mare fines, the Martian fines are lower in Al, higher in Fe, and much higher in S and Cl concentrations. Protected fines at the two lander sites are almost indistinguishable, but concentration of the element S is somewhat higher at Utopia. Duricrust fragments, successfully acquired only at the Chryse site, invariably contained about 50% higher S than fines. No elements correlate positively with S, except Cl and possibly Mg. A sympathetic variation is found among the triad Si, Al, Ca; positive correlation occurs between Ti and Fe. Sample variabilities are as great within a few meters as between lander locations (4500 km apart), implying the existence of a universal Martian regolith component of constant average composition. The nature of the source materials for the regolith fines must be mafic to ultramafic.

  20. Catalytic upgrading of butyric acid towards fine chemicals and biofuels

    PubMed Central

    Sjöblom, Magnus; Matsakas, Leonidas; Christakopoulos, Paul; Rova, Ulrika

    2016-01-01

    Fermentation-based production of butyric acid is robust and efficient. Modern catalytic technologies make it possible to convert butyric acid to important fine chemicals and biofuels. Here, current chemocatalytic and biocatalytic conversion methods are reviewed with a focus on upgrading butyric acid to 1-butanol or butyl-butyrate. Supported Ruthenium- and Platinum-based catalyst and lipase exhibit important activities which can pave the way for more sustainable process concepts for the production of green fuels and chemicals. PMID:26994015

  1. [Starting with camphor--the progress of Nippon Fine Chemical].

    PubMed

    Kimura, Osamu

    2010-01-01

    In 1918, Nippon Fine Chemical Co., Ltd. (NFC) was founded under the name, Nippon Camphor Co., Ltd. for the purpose of unifying the camphor business throughout Japan. The company manufactured purified camphor as a government-monopolized good. Camphor was used as a plasticizer for nitrocellulose, as a moth repellent, as an antimicrobial substance, as a rust inhibitor, and as an active ingredient in medicine. It was also a very important good exported in order to obtain foreign currency. Later on, after World War II and the abolition of the camphor monopoly, the company started manufacturing products related to oils and fats, including higher fatty acids, and expanded its business by developing a new field of chemical industry. In 1971 the company changed its name to Nippon Fine Chemical Co., Ltd., and made a new start as a diversified fine chemicals company. Recently, the fine chemicals division of NFC has concentrated on rather complex molecules, such as active pharmaceutical ingredients, and other chemicals. Since 2000, NFC have started to supply "Presome", precursors of liposome DDS drugs. NFC is strengthening marketing strategies in foreign countries with unique technologies and products.

  2. New trends in (heterogeneous) catalysis for the fine chemicals industry.

    PubMed

    Bonrath, Werner

    2014-01-01

    New catalytic methods and modern trends for the synthesis of fine chemicals, especially vitamins, carotenoids, flavoring and fragrance compounds are presented. In particular the application of heterogeneous catalysis in the formation and production on industrial scale of these classes of organic compounds will be highlighted and its use in the replacement of former stoichiometric processes.

  3. Catalytic conversion of lignocellulosic biomass to fine chemicals and fuels.

    PubMed

    Zhou, Chun-Hui; Xia, Xi; Lin, Chun-Xiang; Tong, Dong-Shen; Beltramini, Jorge

    2011-11-01

    Lignocellulosic biomass is the most abundant and bio-renewable resource with great potential for sustainable production of chemicals and fuels. This critical review provides insights into the state-of the-art accomplishments in the chemocatalytic technologies to generate fuels and value-added chemicals from lignocellulosic biomass, with an emphasis on its major component, cellulose. Catalytic hydrolysis, solvolysis, liquefaction, pyrolysis, gasification, hydrogenolysis and hydrogenation are the major processes presently studied. Regarding catalytic hydrolysis, the acid catalysts cover inorganic or organic acids and various solid acids such as sulfonated carbon, zeolites, heteropolyacids and oxides. Liquefaction and fast pyrolysis of cellulose are primarily conducted over catalysts with proper acidity/basicity. Gasification is typically conducted over supported noble metal catalysts. Reaction conditions, solvents and catalysts are the prime factors that affect the yield and composition of the target products. Most of processes yield a complex mixture, leading to problematic upgrading and separation. An emerging technique is to integrate hydrolysis, liquefaction or pyrolysis with hydrogenation over multifunctional solid catalysts to convert lignocellulosic biomass to value-added fine chemicals and bio-hydrocarbon fuels. And the promising catalysts might be supported transition metal catalysts and zeolite-related materials. There still exist technological barriers that need to be overcome (229 references). This journal is © The Royal Society of Chemistry 2011

  4. Engineering the substrate specificity of cytochrome P450 CYP102A2 by directed evolution: production of an efficient enzyme for bioconversion of fine chemicals.

    PubMed

    Axarli, Irene; Prigipaki, Ariadne; Labrou, Nikolaos E

    2005-06-01

    The P450 cytochromes constitute a large family of hemoproteins that catalyze the monooxygenation of a diversity of hydrophobic substrates. CYP102A2 is a catalytically self-sufficient cytoplasmic enzyme from Bacillus subtilis, containing both a monooxygenase domain and a reductase domain on a single polypeptide chain. CYP102A2 was subjected to error-prone PCR to generate mutants with enhanced activity with fatty acids and other aromatic substrates. The library of CYP102A2 mutants was expressed in BL21(DE3) Escherichia coli cells and screened for their ability to oxidize different substrates by means of an activity assay. After a single round of error-prone PCR, the variant Pro15Ser exhibiting modified substrate specificity was generated. This variant showed approximately 6- to 9-fold increased activity with SDS, lauric acid and 1,4-naphthoquinone, and enhanced activity for other substrates such as ethacrynic acid and epsilon-amino-n-caproic acid. Molecular modeling of the CYP102A2 monooxygenase domain suggested that Pro15 is located in a short helical segment and is involved in extensive interactions between the N-terminal domain and the beta2 sheet, which contribute to the formation of the substrate binding site. Thus, Pro15 appears to affect substrate binding and catalysis indirectly. These results clearly demonstrate the importance of remote residues, not readily predicted by rational design, for the determination of substrate specificity. In addition, we report here that the Pro15Ser variant of CYP102A2 can be efficiently immobilized on epoxy-activated Sepharose at pH 8.5 and 4 degrees C. The immobilized variant of CYP102A2 retains most of its activity (81%) and shows improved stability at 37 degrees C. The approach offers the possibility of designing a P450 bioreactor that can be operated over a long period of time with high efficiency and which can be used in fine chemical synthesis.

  5. Towards novel processes for the fine-chemical and pharmaceutical industries.

    PubMed

    Huisman, Gjalt W; Gray, David

    2002-08-01

    In response to the need in the pharmaceutical industry for more complex, chiral molecules, fine-chemical companies are embracing new manufacturing technologies to produce compounds of these specifications. In particular, recent developments in biocatalysis combined with novel process engineering are providing improved methods for the production of valuable chemical intermediates.

  6. Engineered enzymes for chemical production.

    PubMed

    Luetz, Stephan; Giver, Lori; Lalonde, James

    2008-11-01

    In order to enable competitive manufacturing routes, most biocatalysts must be tailor-made for their processes. Enzymes from nature rarely have the combined properties necessary for industrial chemical production such as high activity and selectivity on non-natural substrates and toleration of high concentrations of organic media over the wide range of conditions (decreasing substrate, increasing product concentrations, solvents, etc.,) that will be present over the course of a manufacturing process. With the advances in protein engineering technologies, a variety of enzyme properties can be altered simultaneously, if the appropriate screening parameters are employed. Here we discuss the process of directed evolution for the generation of commercially viable biocatalysts for the production of fine chemicals, and how novel approaches have helped to overcome some of the challenges.

  7. Calcium, Strontium and Barium Homogeneous Catalysts for Fine Chemicals Synthesis.

    PubMed

    Sarazin, Yann; Carpentier, Jean-François

    2016-12-01

    The large alkaline earths (Ae), calcium, strontium and barium, have in the past 15 years yielded a brand new generation of heteroleptic molecular catalysts for the production of fine chemicals. However, the integrity of these complexes is often plagued by ligand redistribution equilibria in solution. This personal account retraces the paths followed in our research group towards the design of stable heteroleptic alkalino-earth complexes, including the use of intramolecular noncovalent Ae···H-Si and Ae···F-C interactions. Their implementation as homogenous precatalysts for reactions such as the intramolecular and intermolecular hydroamination and hydrophosphination of activated alkenes, the hydrophosphonylation of ketones, and the dehydrogenative coupling of amines and hydrosilanes that enable the efficient and controlled formations of CP, CN, or SiN σ-bonds, is presented in a synthetic perspective that highlights their overall outstanding catalytic performance. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Chemicals and Allied Products.

    ERIC Educational Resources Information Center

    Nelson, R. F.; Hovious, J. C.

    1978-01-01

    Presents a literature review of wastes from chemical industry, covering publications of 1976-77. This review covers: (1) wastewater treatment by-product type; (2) biological, and physical/chemical treatments; and (3) source treatment. A list of 80 references is also presented. (HM)

  9. Chemicals and Allied Products.

    ERIC Educational Resources Information Center

    Nelson, R. F.; Hovious, J. C.

    1978-01-01

    Presents a literature review of wastes from chemical industry, covering publications of 1976-77. This review covers: (1) wastewater treatment by-product type; (2) biological, and physical/chemical treatments; and (3) source treatment. A list of 80 references is also presented. (HM)

  10. Fine particulate chemical composition and light extinction at Meadview, AZ.

    PubMed

    Eatough, Delbert J; Cui, Wenxuan; Hull, Jeffery; Farber, Robert J

    2006-12-01

    The concentration of fine particulate nitrate, sulfate, and carbonaceous material was measured for 12-hr day-night samples using diffusion denuder samplers during the Project Measurement of Haze and Visibility Effects (MOHAVE) July to August 1992 Summer Intensive study at Meadview, AZ, just west of Grand Canyon National Park. Organic material was measured by several techniques. Only the diffusion denuder method measured the semivolatile organic material. Fine particulate sulfate and nitrate (using denuder technology) determined by various groups agreed. Based on the various collocated measurements obtained during the Project MOHAVE study, the precision of the major fine particulate species was +/- 0.6 microg/m3 organic material, +/- 0.3 microg/m3 ammonium sulfate, and +/- 0.07 microg/m3 ammonium nitrate. Data were also available on fine particulate crustal material, fine and coarse particulate mass from the Interagency Monitoring of Protected Visual Environments sampling system, and relative humidity (RH), light absorption, particle scattering, and light extinction measurements from Project MOHAVE. An extinction budget was obtained using mass scattering coefficients estimated from particle size distribution data. Literature data were used to estimate the change in the mass scattering coefficients for the measured species as a function of RH and for the absorption of light by elemental carbon. Fine particulate organic material was the principal particulate contributor to light extinction during the study period, with fine particulate sulfate as the second most important contributor. During periods of highest light extinction, contributions from fine particulate organic material, sulfate, and light-absorbing carbon dominated the extinction of light by particles. Particle light extinction was dominated by sulfate and organic material during periods of lowest light extinction. Combination of the extinction data and chemical mass balance analysis of sulfur oxides

  11. Cyanobacterial chemical production.

    PubMed

    Case, Anna E; Atsumi, Shota

    2016-08-10

    The increase in global temperatures caused by rising CO2 levels necessitates the development of alternative sources of fuel and chemicals. One appealing alternative that has been receiving increased attention in recent years is the photosynthetic conversion of atmospheric CO2 to biofuels and chemical products using genetically engineered cyanobacteria. This can help to not only provide an alternate "greener" source for some of the most popular petroleum based products but it can also help to reduce atmospheric CO2. Utilizing cyanobacteria rather than plants allows for reduced land requirements and reduces competition with food crops. This review discusses advancements in the field since 2012 with a particular emphasis on production of hydrocarbons.

  12. Fine particulate chemical composition and light extinction at Meadview, AZ

    SciTech Connect

    Delbert J. Eatough; Wenxuan Cui; Jeffery Hull; Robert J. Farber

    2006-12-15

    The concentration of fine particulate nitrate, sulfate, and carbonaceous material was measured for 12-hr daynight samples using diffusion denuder samplers during the Project Measurement of Haze and Visibility Effects (MOHAVE) July to August 1992 Summer Intensive study at Meadview, AZ, just west of Grand Canyon National Park. Organic material was measured by several techniques. Only the diffusion denuder method measured the semivolatile organic material. Fine particulate sulfate and nitrate (using denuder technology) determined by various groups agreed. Based on the various collocated measurements obtained during the Project MOHAVE study, the precision of the major fine particulate species was {+-} 0.6 {mu}g/m{sup 3} organic material, {+-} 0.3 {mu}g/m{sup 3} ammonium sulfate, and {+-} 0.07 {mu}g/m{sup 3} ammonium nitrate. Fine particulate organic material was the principal particulate contributor to light extinction during the study period, with fine particulate sulfate as the second most important contributor. Particle light extinction was dominated by sulfate and organic material during periods of lowest light extinction. Combination of the extinction data and chemical mass balance analysis of sulfur oxides sources in the region indicate that the major anthropogenic contributors to light extinction were from the Los Angeles, CA, and Las Vegas, NV, urban areas. Mohave Power Project associated secondary sulfate was a negligible contributor to light extinction. 49 refs., 12 figs., 7 tabs.

  13. Production of fine chemicals using biocatalysis.

    PubMed

    Liese, A; Filho, M V

    1999-12-01

    Presently, a large number of biotransformations are carried out on an industrial scale and are discussed in a fast increasing number of reviews. Besides this, a significant number of biotransformations have been investigated over the past year, from degrading to transforming and synthetic reactions. The development of more specific and stable biocatalysts, either isolated enzymes or whole cells, generated by the new methods of genetic engineering and improved by reaction engineering have led to new industrial biotransformations.

  14. Creating pathways towards aromatic building blocks and fine chemicals.

    PubMed

    Thompson, Brian; Machas, Michael; Nielsen, David R

    2015-12-01

    Aromatic compounds represent a broad class of chemicals with a range of industrial applications, all of which are conventionally derived from petroleum feedstocks. However, owing to a diversity of available pathway precursors along with natural and engineered enzyme 'parts', microbial cell factories can be engineered to create alternative, renewable routes to many of the same aromatic products. Drawing from the latest tools and strategies in metabolic engineering and synthetic biology, such efforts are becoming an increasingly systematic practice, while continued efforts promise to open new doors to an ever-expanding range and diversity of renewable chemical and material products. This short review will highlight recent and notable achievements related for the microbial production of aromatic chemicals.

  15. Oil sands fine tailings - a resource material for potentially marketable products

    SciTech Connect

    Majid, A.; Sparks, B.D.; Coleman, R.D.

    1995-12-31

    Oil sands fine tailings is a complex mixture of components each having specific physical or chemical characteristics. Studies on the fundamental properties of fine tailings have resulted in the development of methods to fractionate the tailings into products with market potential. These include: bitumen, for production of synthetic crude oil or as an ancillary fuel; clean kaolin for fine paper coating; a gelling agent for drilling mud formulation; emulsifying solids, for surfactant replacement; and a mineral fraction, for heavy metal recovery. In this investigation we have attempted to evaluate the economic potential of fine tailings as a resource material by determining the amount and value of these products; the prime objective was to determine the economic feasibility of a tailings treatment scheme.

  16. Combined Chemical Activation and Fenton Degradation to Convert Waste Polyethylene into High-Value Fine Chemicals.

    PubMed

    Chow, Cheuk-Fai; Wong, Wing-Leung; Ho, Keith Yat-Fung; Chan, Chung-Sum; Gong, Cheng-Bin

    2016-07-04

    Plastic waste is a valuable organic resource. However, proper technologies to recover usable materials from plastic are still very rare. Although the conversion/cracking/degradation of certain plastics into chemicals has drawn much attention, effective and selective cracking of the major waste plastic polyethylene is extremely difficult, with degradation of C-C/C-H bonds identified as the bottleneck. Pyrolysis, for example, is a nonselective degradation method used to crack plastics, but it requires a very high energy input. To solve the current plastic pollution crisis, more effective technologies are needed for converting plastic waste into useful substances that can be fed into the energy cycle or used to produce fine chemicals for industry. In this study, we demonstrate a new and effective chemical approach by using the Fenton reaction to convert polyethylene plastic waste into carboxylic acids under ambient conditions. Understanding the fundamentals of this new chemical process provides a possible protocol to solve global plastic-waste problems.

  17. 78 FR 69134 - Manufacturer of Controlled Substances; Notice of Registration: AMPAC Fine Chemicals, LLC.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... Enforcement Administration Manufacturer of Controlled Substances; Notice of Registration: AMPAC Fine Chemicals, LLC. By Notice dated July 23, 2013, and published in the Federal Register on July 31, 2013, 78 FR 46372, AMPAC Fine Chemicals, LLC., Highway 50 and Hazel Avenue, Building 05001, Rancho...

  18. Catalytic Conversion of Renewable Resources into Bulk and Fine Chemicals.

    PubMed

    de Vries, Johannes G

    2016-12-01

    Several strategies can be chosen to convert renewable resources into chemicals. In this account, I exemplify the route that starts with so-called platform chemicals; these are relatively simple chemicals that can be produced in high yield, directly from renewable resources, either via fermentation or via chemical routes. They can be converted into the existing bulk chemicals in a very efficient manner using multistep catalytic conversions. Two examples are given of the conversion of sugars into nylon intermediates. 5-Hydroxymethylfurfural (HMF) can be prepared in good yield from fructose. Two hydrogenation steps convert HMF into 1,6-hexanediol. Oppenauer oxidation converts this product into caprolactone, which in the past, has been converted into caprolactam in a large-scale industrial process by reaction with ammonia. An even more interesting platform chemical is levulinic acid (LA), which can be obtained directly from lignocellulose in good yield by treatment with dilute sulfuric acid at 200°C. Hydrogenation converts LA into gamma-valerolactone, which is ring-opened and esterified in a gas-phase process to a mixture of isomeric methyl pentenoates in excellent selectivity. In a remarkable selective palladium-catalysed isomerising methoxycarbonylation, this mixture is converted in to dimethyl adipate, which is finally hydrolysed to adipic acid. Overall selectivities of both processes are extremely high. The conversion of lignin into chemicals is a much more complicated task in view of the complex nature of lignin. It was discovered that breakage of the most prevalent β-O-4 bond in lignin occurs not only via the well-documented C3 pathway, but also via a C2 pathway, leading to the formation of highly reactive phenylacetaldehydes. These compounds went largely unnoticed as they immediately recondense on lignin. We have now found that it is possible to prevent this by converting these aldehydes in a tandem reaction, as they are formed. For this purpose, we have used

  19. Clean Production of Coke from Carbonaceous Fines

    SciTech Connect

    Craig N. Eatough

    2004-11-16

    In order to produce steel (a necessary commodity in developed nations) using conventional technologies, you must have metallurgical coke. Current coke-making technology pyrolyzes high-quality coking coals in a slot oven, but prime coking coals are becoming more expensive and slot ovens are being shut-down because of age and environmental problems. The United States typically imports about 4 million tons of coke per year, but because of a world-wide coke scarcity, metallurgical coke costs have risen from about $77 per tonne to more than $225. This coke shortage is a long-term challenge driving up the price of steel and is forcing steel makers to search for alternatives. Combustion Resources (CR) has developed a technology to produce metallurgical coke from alternative feedstocks in an environmentally clean manner. The purpose of the current project was to refine material and process requirements in order to achieve improved economic benefits and to expand upon prior work on the proposed technology through successful prototype testing of coke products. The ultimate objective of this project is commercialization of the proposed technology. During this project period, CR developed coke from over thirty different formulations that meet the strength and reactivity requirements for use as metallurgical coke. The technology has been termed CR Clean Coke because it utilizes waste materials as feedstocks and is produced in a continuous process where pollutant emissions can be significantly reduced compared to current practice. The proposed feed material and operating costs for a CR Clean Coke plant are significantly less than conventional coke plants. Even the capital costs for the proposed coke plant are about half that of current plants. The remaining barrier for CR Clean Coke to overcome prior to commercialization is full-scale testing in a blast furnace. These tests will require a significant quantity of product (tens of thousands of tons) necessitating the construction

  20. Chemical Waste and Allied Products.

    PubMed

    Hung, Yung-Tse; Aziz, Hamidi Abdul; Ramli, Siti Fatihah; Yeh, Ruth Yu-Li; Liu, Lian-Huey; Huhnke, Christopher Robert

    2016-10-01

    This review of literature published in 2015 focuses on waste related to chemical and allied products. The topics cover the waste management, physicochemical treatment, aerobic granular, aerobic waste treatment, anaerobic granular, anaerobic waste treatment, chemical waste, chemical wastewater, fertilizer waste, fertilizer wastewater, pesticide wastewater, pharmaceutical wastewater, ozonation. cosmetics waste, groundwater remediation, nutrient removal, nitrification denitrification, membrane biological reactor, and pesticide waste.

  1. Chromium Extraction via Chemical Processing of Fe-Cr Alloys Fine Powder with High Carbon Content

    NASA Astrophysics Data System (ADS)

    Torres, D. M.; Navarro, R. C. S.; Souza, R. F. M.; Brocchi, E. A.

    2017-03-01

    Ferrous alloys are important raw materials for special steel production. In this context, alloys from the Fe-Cr system, with typical Cr weight fraction ranging from 0.45 to 0.95, are prominent, particularly for the stainless steel industry. During the process in which these alloys are obtained, there is considerable production of fine powder, which could be reused after suitable chemical treatment, for example, through coupling pyrometallurgical and hydrometallurgical processes. In the present study, the extraction of chromium from fine powder generated during the production of a Fe-Cr alloy with high C content was investigated. Roasting reactions were performed at 1073 K, 1173 K, and 1273 K (800 °C, 900 °C, and 1000 °C) with 300 pct (w/w) excess NaOH in an oxidizing atmosphere (air), followed by solubilization in deionized water, selective precipitation, and subsequent calcination at 1173 K (900 °C) in order to convert the obtained chromium hydroxide to Cr2O3. The maximum achieved Cr recovery was around 86 pct, suggesting that the proposed chemical route was satisfactory regarding the extraction of the chromium initially present. Moreover, after X-ray diffraction analysis, the final produced oxide has proven to be pure Cr2O3 with a mean crystallite size of 200 nm.

  2. Chromium Extraction via Chemical Processing of Fe-Cr Alloys Fine Powder with High Carbon Content

    NASA Astrophysics Data System (ADS)

    Torres, D. M.; Navarro, R. C. S.; Souza, R. F. M.; Brocchi, E. A.

    2017-06-01

    Ferrous alloys are important raw materials for special steel production. In this context, alloys from the Fe-Cr system, with typical Cr weight fraction ranging from 0.45 to 0.95, are prominent, particularly for the stainless steel industry. During the process in which these alloys are obtained, there is considerable production of fine powder, which could be reused after suitable chemical treatment, for example, through coupling pyrometallurgical and hydrometallurgical processes. In the present study, the extraction of chromium from fine powder generated during the production of a Fe-Cr alloy with high C content was investigated. Roasting reactions were performed at 1073 K, 1173 K, and 1273 K (800 °C, 900 °C, and 1000 °C) with 300 pct (w/w) excess NaOH in an oxidizing atmosphere (air), followed by solubilization in deionized water, selective precipitation, and subsequent calcination at 1173 K (900 °C) in order to convert the obtained chromium hydroxide to Cr2O3. The maximum achieved Cr recovery was around 86 pct, suggesting that the proposed chemical route was satisfactory regarding the extraction of the chromium initially present. Moreover, after X-ray diffraction analysis, the final produced oxide has proven to be pure Cr2O3 with a mean crystallite size of 200 nm.

  3. Fundamental hair follicle biology and fine fibre production in animals.

    PubMed

    Galbraith, H

    2010-09-01

    Hair 'fine' fibre is an important commercial product of farmed and certain wild animal species. The fibre is produced in follicles embedded in skin. These have properties in common with other tissues of the integument and have importance in determining yield and quality of fibre. Means of understanding and improving these characteristics are informed by knowledge of integumental and follicle biology. This paper reviews contemporary information that identifies the major fibre-producing species and their production characteristic. It surveys knowledge describing fundamental biology of the integument and considers information derived for the hair follicle from studies on a number of species including genetically modified mice. It identifies the composition of the follicle and describes components and interrelationships between epidermal hair-fibre producing epidermis and fibroblast- and connective tissue-containing dermis. The structure of different primary and secondary follicle types, and associated structures, are described. Focus is given to the alterations in anatomy and in behaviour from active to inactive state, which occurs during the hair follicle cycle. Information is provided on the anatomical substructures (hair medulla, cortex, cuticles and supporting sheaths and dermal papilla), cellular and extracellular composition, and adhesion and chemical signalling systems, which regulate development from the early embryo to post-natal state and subsequent cycling. Such signalling involves the dermis and its specialist fibroblasts, which secrete signalling molecules, which along with those from local epidermis and systemic sources, largely determine structure and function of epidermal cells. Such chemical signalling typically includes endocrine-, paracrine-, autocrine- and juxtacrine-acting molecules and interactions with their receptors located on cell membranes or intracellularly with transduction of message mediated by transcription factors at gene level

  4. Conversion of biomass to selected chemical products.

    PubMed

    Gallezot, Pierre

    2012-02-21

    This critical review provides a survey illustrated by recent references of different strategies to achieve a sustainable conversion of biomass to bioproducts. Because of the huge number of chemical products that can be potentially manufactured, a selection of starting materials and targeted chemicals has been done. Also, thermochemical conversion processes such as biomass pyrolysis or gasification as well as the synthesis of biofuels were not considered. The synthesis of chemicals by conversion of platform molecules obtained by depolymerisation and fermentation of biopolymers is presently the most widely envisioned approach. Successful catalytic conversion of these building blocks into intermediates, specialties and fine chemicals will be examined. However, the platform molecule value chain is in competition with well-optimised, cost-effective synthesis routes from fossil resources to produce chemicals that have already a market. The literature covering alternative value chains whereby biopolymers are converted in one or few steps to functional materials will be analysed. This approach which does not require the use of isolated, pure chemicals is well adapted to produce high tonnage products, such as paper additives, paints, resins, foams, surfactants, lubricants, and plasticisers. Another objective of the review was to examine critically the green character of conversion processes because using renewables as raw materials does not exempt from abiding by green chemistry principles (368 references).

  5. Chemical Waste and Allied Products.

    PubMed

    Hung, Yung-Tse; Aziz, Hamidi Abdul; Yusoff, Mohd Suffian; Kamaruddin, Mohamad Anuar; Yeh, Ruth Yu-Li; Liu, Lian-Huey; Huhnke, Christopher Robert; Fu, Yen-Pei

    2015-10-01

    This review of literature published in 2014 focuses on waste related to chemical and allied products. The topics cover the waste management practices, hospital waste, pesticide waste, chemical wastewater, pesticide wastewater and pharmaceutical wastewater. The other topics include aerobic treatment, anaerobic treatment, sorption and ozonation.

  6. The origin of the distortion product otoacoustic emission fine structure

    NASA Astrophysics Data System (ADS)

    Piskorski, Pawel

    Distortion-product otoacoustic emissions (DPOAEs) are sounds detected in the ear canal which are generated by the nonlinear processes in the inner ear (cochlea) in response to the external stimulation of two or more tones (primaries). Their generation region in the cochlea can be systematically changed by varying the primary frequencies, and they are currently being evaluated for possible clinical use in screening for hearing defects. The phase and amplitude of various orders of DPOAEs of frequencies, f/sb [dp]=f1-n(f2-f1),/ (n=1,2,/...), were measured in human subjects for two- tone stimuli of frequencies f1 and f2 (>f1). A number of experimental paradigms (fixed primary ratio f2/f1, fixed f1, fixed f2, and fixed f/sb [dp]) were used to investigate the nature of peaks and valleys (fine structure) of DPOAEs in their phase and amplitude dependence on the primary frequencies. This fine structure must be taken into account in any potential clinical applications of DPOAEs. The experimental results largely support a model in which the fine structure stems from interference at the base of the cochlea between distortion product (DP) components coming from the primary DPOAE source region (around the f2 tonotopic place) and components coming from the DP tonotopic place (via reflection of an apically moving DP wave). The spectral periodicity of the fine structures for several orders of apical DPOAEs corresponds to a tonotopic displacement of about 0.4 mm along the basilar membrane (BM) (0.4 bark). In agreement with the reaction model, this spectral spacing is also characteristic of synchronous evoked and spontaneous otoacoustic emission spectra as well as the microstructure of the hearing threshold. Approximate analytic expressions for the mechanisms which are responsible for the fine structure are used to interpret the data.

  7. OPTIMIZING MINIRHIZOTRON SAMPLE FREQUENCY FOR ESTIMATING FINE ROOT PRODUCTION AND TURNOVER

    EPA Science Inventory

    The most frequent reason for using minirhizotrons in natural ecosystems is the determination of fine root production and turnover. Our objective is to determine the optimum sampling frequency for estimating fine root production and turnover using data from evergreen (Pseudotsuga ...

  8. OPTIMIZING MINIRHIZOTRON SAMPLE FREQUENCY FOR ESTIMATING FINE ROOT PRODUCTION AND TURNOVER

    EPA Science Inventory

    The most frequent reason for using minirhizotrons in natural ecosystems is the determination of fine root production and turnover. Our objective is to determine the optimum sampling frequency for estimating fine root production and turnover using data from evergreen (Pseudotsuga ...

  9. Fine Root Productivity and Dynamics on a Forested Floodplain in South Carolina

    Treesearch

    Terrell T. Baker; William Conner; H. B. Graeme Lockaby; John A. Stanturf; Marianne K. Burke

    2001-01-01

    The highly dynamic, fine root component of forested wetland ecosystems fine root dynamics is a challenging endeavor in any system, but the difficulties are particularly evident in forested floodplains where frequent hydrologic fluctuations directly influence fine root dynamics. Fine root (53 mm) biomass, production, and turnover were estimated for three soils...

  10. Natural Products as Chemical Probes

    PubMed Central

    Carlson, Erin E.

    2010-01-01

    Natural products have evolved to encompass a broad spectrum of chemical and functional diversity. It is this diversity, along with their structural complexity, that enables nature’s small molecules to target a nearly limitless number of biological macromolecules and to often do so in a highly selective fashion. Because of these characteristics, natural products have seen great success as therapeutic agents. However, this vast pool of compounds holds much promise beyond the development of future drugs. These features also make them ideal tools for the study of biological systems. Recent examples of the use of natural products and their derivatives as chemical probes to explore biological phenomena and assemble biochemical pathways are presented here. PMID:20509672

  11. Stored carbon partly fuels fine-root respiration but is not used for production of new fine roots

    SciTech Connect

    Lynch, Douglas J; Matamala-Paradeda, Roser; Iversen, Colleen M; Norby, Richard J; Gonzalez-Meler, Miguel A

    2013-01-01

    The relative use of new photosynthate compared to stored C for the production and maintenance of fine roots, and the rate of C turnover in heterogeneous fine-root populations, are poorly understood. We followed the relaxation of a 13C tracer in fine roots in a Liquidambar styraciflua plantation at the conclusion of a free-air CO2 enrichment experiment. Goals included quantifying the relative fractions of new photosynthate versus stored C used in root growth and root respiration, as well as the turnover rate of fine-root C fixed during [CO2] fumigation. New fine-root growth was largely from recent photosynthate, while nearly one-quarter of respired C was from a storage pool. Changes in the isotopic composition of the fine-root population over two full growing seasons indicated heterogeneous C pools; less than 10% of root C had a residence time < 3 months, while a majority of root C had a residence time > 2 years. Compared to a 1-pool model, a 2-pool model for C turnover in fine roots (with 5 and 0.37 yr-1 turnover times) doubles the fine-root contribution to forest NPP (9-13%) and supports the 50% root-to-soil transfer rate often used in models.

  12. Stored carbon partly fuels fine-root respiration but is not used for production of new fine roots.

    PubMed

    Lynch, Douglas J; Matamala, Roser; Iversen, Colleen M; Norby, Richard J; Gonzalez-Meler, Miquel A

    2013-07-01

    The relative use of new photosynthate compared to stored carbon (C) for the production and maintenance of fine roots, and the rate of C turnover in heterogeneous fine-root populations, are poorly understood. We followed the relaxation of a (13)C tracer in fine roots in a Liquidambar styraciflua plantation at the conclusion of a free-air CO(2) enrichment experiment. Goals included quantifying the relative fractions of new photosynthate vs stored C used in root growth and root respiration, as well as the turnover rate of fine-root C fixed during [CO(2)] fumigation. New fine-root growth was largely from recent photosynthate, while nearly one-quarter of respired C was from a storage pool. Changes in the isotopic composition of the fine-root population over two full growing seasons indicated heterogeneous C pools; < 10% of root C had a residence time < 3 months, while a majority of root C had a residence time > 2 yr. Compared to a one-pool model, a two-pool model for C turnover in fine roots (with 5 and 0.37 yr(-1) turnover times) doubles the fine-root contribution to forest NPP (9-13%) and supports the 50% root-to-soil transfer rate often used in models. No claim to original US government works. New Phytologist © 2013 New Phytologist Trust.

  13. Entropy Production in Chemical Reactors

    NASA Astrophysics Data System (ADS)

    Kingston, Diego; Razzitte, Adrián C.

    2017-06-01

    We have analyzed entropy production in chemically reacting systems and extended previous results to the two limiting cases of ideal reactors, namely continuous stirred tank reactor (CSTR) and plug flow reactor (PFR). We have found upper and lower bounds for the entropy production in isothermal systems and given expressions for non-isothermal operation and analyzed the influence of pressure and temperature in entropy generation minimization in reactors with a fixed volume and production. We also give a graphical picture of entropy production in chemical reactions subject to constant volume, which allows us to easily assess different options. We show that by dividing a reactor into two smaller ones, operating at different temperatures, the entropy production is lowered, going as near as 48 % less in the case of a CSTR and PFR in series, and reaching 58 % with two CSTR. Finally, we study the optimal pressure and temperature for a single isothermal PFR, taking into account the irreversibility introduced by a compressor and a heat exchanger, decreasing the entropy generation by as much as 30 %.

  14. Litterfall production and fine root dynamics in cool-temperate forests

    PubMed Central

    Chun, Jung Hwa; Osawa, Akira

    2017-01-01

    Current understanding of litterfall and fine root dynamics in temperate forests is limited, even though these are the major contributors to carbon and nutrient cycling in the ecosystems. In this study, we investigated litterfall and fine root biomass and production in five deciduous and four coniferous forests at the Gwangneung Experimental Forest in Korea. We used ingrowth cores to measure fine root production and root turnover rate. The litterfall was separated into leaves, twigs, and others, and then leaves were further separated according to species. Annual litterfall mass was not significantly different between the years, 360 to 651 g m-2 in 2011 and 300 to 656 g m-2 in 2012. Annual fine root (<5 mm) production was significantly higher in 2012 (421 to 1342 g m-2) than in 2011 (99 to 872 g m-2). Annual litterfall mass was significantly different among the stands, while fine root production did not statistically differ among the stands. The average fine root turnover rate, calculated by dividing the annual fine root production by the maximum standing fine root biomass, was 1.65 for deciduous forests and 1.97 for coniferous forests. Fine root production constituted 18–44% of NPP, where NPP was the sum of woody biomass production, litterfall production, and fine root production. Belowground production was a greater fraction of NPP in more productive forests suggesting their greater carbon allocation belowground. PMID:28662215

  15. Litterfall production and fine root dynamics in cool-temperate forests.

    PubMed

    An, Ji Young; Park, Byung Bae; Chun, Jung Hwa; Osawa, Akira

    2017-01-01

    Current understanding of litterfall and fine root dynamics in temperate forests is limited, even though these are the major contributors to carbon and nutrient cycling in the ecosystems. In this study, we investigated litterfall and fine root biomass and production in five deciduous and four coniferous forests at the Gwangneung Experimental Forest in Korea. We used ingrowth cores to measure fine root production and root turnover rate. The litterfall was separated into leaves, twigs, and others, and then leaves were further separated according to species. Annual litterfall mass was not significantly different between the years, 360 to 651 g m-2 in 2011 and 300 to 656 g m-2 in 2012. Annual fine root (<5 mm) production was significantly higher in 2012 (421 to 1342 g m-2) than in 2011 (99 to 872 g m-2). Annual litterfall mass was significantly different among the stands, while fine root production did not statistically differ among the stands. The average fine root turnover rate, calculated by dividing the annual fine root production by the maximum standing fine root biomass, was 1.65 for deciduous forests and 1.97 for coniferous forests. Fine root production constituted 18-44% of NPP, where NPP was the sum of woody biomass production, litterfall production, and fine root production. Belowground production was a greater fraction of NPP in more productive forests suggesting their greater carbon allocation belowground.

  16. Synthesis of renewable fine-chemical building blocks by reductive coupling between furfural derivatives and terpenes.

    PubMed

    Nicklaus, Céline M; Minnaard, Adriaan J; Feringa, Ben L; de Vries, Johannes G

    2013-09-01

    Sugar and Spice…: The use of renewable resources to produce fine chemicals is an underdeveloped area. A waste-free technology will be necessary to further convert platform chemicals, readily available from biomass. We show that furfurals, which can be obtained from C5 sugars, can be coupled with terpenes in up to 95% yield through ruthenium-catalyzed reductive couplings developed by Krische et al.

  17. 77 FR 24988 - Manufacturer of Controlled Substances; Notice of Registration; ISP Freetown Fine Chemicals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ..., verification of the company's compliance with state and local laws, and a review of the company's background... Amphetamine (1100) II Phenylacetone (8501) II The company plans to manufacture bulk API, for distribution to... ISP Freetown Fine Chemicals to ensure that the company's registration is consistent with the public...

  18. 78 FR 5500 - Manufacturer of Controlled Substances; Notice of Registration; Ampac Fine Chemicals, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-25

    ...; verification of the company's compliance with state and local laws; and a review of the company's background... II. The company plans to manufacture the listed controlled substance for distribution to its... AMPAC Fine Chemicals, LLC to ensure that the company's registration is consistent with the public...

  19. 77 FR 60145 - Manufacturer of Controlled Substances; Notice of Application; AMPAC Fine Chemicals, LLC

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF JUSTICE Drug Enforcement Administration Manufacturer of Controlled Substances; Notice of Application; AMPAC Fine Chemicals..., California 95670, made application by letter to the Drug Enforcement Administration (DEA) to be registered...

  20. CHEMICAL ANALYSIS OF WORLD TRADE CENTER FINE PARTICULATE MATTER FOR USE IN TOXICOLOGICAL ASSESSMENT

    EPA Science Inventory

    Chemical Analysis of World Trade Center Fine Particulate Matter for Use in Toxicological Assessment
    John K. McGee1, Lung Chi Chen2, Mitchell D. Cohen2, Glen R. Chee2, Colette M. Prophete2, Najwa Haykal-Coates1, Shirley J. Wasson3, Teri L. Conner4, Daniel L. Costa1, and Steph...

  1. CHEMICAL ANALYSIS OF WORLD TRADE CENTER FINE PARTICULATE MATTER FOR USE IN TOXICOLOGICAL ASSESSMENT

    EPA Science Inventory

    Chemical Analysis of World Trade Center Fine Particulate Matter for Use in Toxicological Assessment
    John K. McGee1, Lung Chi Chen2, Mitchell D. Cohen2, Glen R. Chee2, Colette M. Prophete2, Najwa Haykal-Coates1, Shirley J. Wasson3, Teri L. Conner4, Daniel L. Costa1, and Steph...

  2. Estimate of fine root production including the impact of decomposed roots in a Bornean tropical rainforest

    NASA Astrophysics Data System (ADS)

    Katayama, Ayumi; Khoon Koh, Lip; Kume, Tomonori; Makita, Naoki; Matsumoto, Kazuho; Ohashi, Mizue

    2016-04-01

    Considerable carbon is allocated belowground and used for respiration and production of roots. It is reported that approximately 40 % of GPP is allocated belowground in a Bornean tropical rainforest, which is much higher than those in Neotropical rainforests. This may be caused by high root production in this forest. Ingrowth core is a popular method for estimating fine root production, but recent study by Osawa et al. (2012) showed potential underestimates of this method because of the lack of consideration of the impact of decomposed roots. It is important to estimate fine root production with consideration for the decomposed roots, especially in tropics where decomposition rate is higher than other regions. Therefore, objective of this study is to estimate fine root production with consideration of decomposed roots using ingrowth cores and root litter-bag in the tropical rainforest. The study was conducted in Lambir Hills National Park in Borneo. Ingrowth cores and litter bags for fine roots were buried in March 2013. Eighteen ingrowth cores and 27 litter bags were collected in May, September 2013, March 2014 and March 2015, respectively. Fine root production was comparable to aboveground biomass increment and litterfall amount, and accounted only 10% of GPP in this study site, suggesting most of the carbon allocated to belowground might be used for other purposes. Fine root production was comparable to those in Neotropics. Decomposed roots accounted for 18% of fine root production. This result suggests that no consideration of decomposed fine roots may cause underestimate of fine root production.

  3. A global analysis of fine root production as affected by soil nitrogen and phosphorus

    PubMed Central

    Yuan, Z. Y.; Chen, Han Y. H.

    2012-01-01

    Fine root production is the largest component of belowground production and plays substantial roles in the biogeochemical cycles of terrestrial ecosystems. The increasing availability of nitrogen (N) and phosphorus (P) due to human activities is expected to increase aboveground net primary production (ANNP), but the response of fine root production to N and P remains unclear. If roots respond to nutrients as ANNP, fine root production is anticipated to increase with increasing soil N and P. Here, by synthesizing data along the nutrient gradient from 410 natural habitats and from 469 N and/or P addition experiments, we showed that fine root production increased in terrestrial ecosystems with an average increase along the natural N gradient of up to 0.5 per cent with increasing soil N. Fine root production also increased with soil P in natural conditions, particularly at P < 300 mg kg−1. With N, P and combined N + P addition, fine root production increased by a global average of 27, 21 and 40 per cent, respectively. However, its responses differed among ecosystems and soil types. The global average increases in fine root production are lower than those of ANNP, indicating that above- and belowground counterparts are coupled, but production allocation shifts more to aboveground with higher soil nutrients. Our results suggest that the increasing fertilizer use and combined N deposition at present and in the future will stimulate fine root production, together with ANPP, probably providing a significant influence on atmospheric CO2 emissions. PMID:22764168

  4. A global analysis of fine root production as affected by soil nitrogen and phosphorus.

    PubMed

    Yuan, Z Y; Chen, Han Y H

    2012-09-22

    Fine root production is the largest component of belowground production and plays substantial roles in the biogeochemical cycles of terrestrial ecosystems. The increasing availability of nitrogen (N) and phosphorus (P) due to human activities is expected to increase aboveground net primary production (ANNP), but the response of fine root production to N and P remains unclear. If roots respond to nutrients as ANNP, fine root production is anticipated to increase with increasing soil N and P. Here, by synthesizing data along the nutrient gradient from 410 natural habitats and from 469 N and/or P addition experiments, we showed that fine root production increased in terrestrial ecosystems with an average increase along the natural N gradient of up to 0.5 per cent with increasing soil N. Fine root production also increased with soil P in natural conditions, particularly at P < 300 mg kg(-1). With N, P and combined N + P addition, fine root production increased by a global average of 27, 21 and 40 per cent, respectively. However, its responses differed among ecosystems and soil types. The global average increases in fine root production are lower than those of ANNP, indicating that above- and belowground counterparts are coupled, but production allocation shifts more to aboveground with higher soil nutrients. Our results suggest that the increasing fertilizer use and combined N deposition at present and in the future will stimulate fine root production, together with ANPP, probably providing a significant influence on atmospheric CO(2) emissions.

  5. Chemical weathering trends in fine-grained ephemeral stream sediments of the McMurdo Dry Valleys, Antarctica

    NASA Astrophysics Data System (ADS)

    Marra, Kristen R.; Elwood Madden, Megan E.; Soreghan, Gerilyn S.; Hall, Brenda L.

    2017-03-01

    sediments exhibiting the highest surface area in Delta Stream suggest that chemical weathering may result in pitting and/or incongruent dissolution of pyroxenes and feldspars, as well as the development of amorphous and/or nanophase weathering products. In contrast, Clark Glacier stream sediments do not have similar leaching trends in the fine-grained sediment fraction and exhibit minimal weathering overall. This may suggest that fine-grained material is being trapped on top of the Clark Glacier surface and has not yet been transported into the weathering environment of the hyporheic zone due to timing of sampling. Alternatively, complete dissolution of very fine-grained sediment could be occurring in this stream transect, and is therefore not preserved in the fine sediment fraction. Overall, the magnitude of chemical weathering observed between the two stream systems is ultimately related to the nature of the underlying drift (cold and wet-based drift deposition), dispersal patterns of eolian fines, and variable stream discharge rates. Thus, incorporation of local fine-grained sediment derived from the underlying glacial drift deposits and distributed via the varying wind regimes within the hyper-arid climate into active stream channels may facilitate incongruent mineral dissolution and development of weathering products, and ultimately influence the composition and concentration of meltwater stream solutes.

  6. Fine-scale chemical exposure differs in point and nonpoint source plumes.

    PubMed

    Lahman, Sara E; Moore, Paul A

    2015-05-01

    Increasing influxes of anthropogenic chemicals into aquatic ecosystems has led to growing global concern surrounding human and ecosystem health. As more freshwater systems are deemed not potable or usable for agricultural purposes, more attention is being paid to remediation and mitigation efforts. Predicting and preventing the impacts of the chemical inputs first requires a thorough understanding of the spatio-temporal distribution of chemical plumes in natural habitats. Plume dispersion is intimately tied to fluid mechanics; therefore, alterations in the way that chemical plumes are introduced to habitats can have profound effects on chemical distribution. Such alterations can subsequently alter the exposure to which organisms are subjected. This study examined the influence of point versus nonpoint sources in structuring the distribution of chemicals in a simulated flowing freshwater habitat. The fine-scale (molecular) spatio-temporal distribution of chemicals was measured in situ using an electrochemical detector. Molecular concentration at varying distance and height from the source was quantified using dopamine coupled with an electrochemical detection system. The fine-scale distribution of chemical plumes from point and nonpoint sources showed significant differences in how organisms will be exposed to chemicals. Overall, this study characterized plumes from nonpoint sources as having significantly longer peak lengths and rise times as well as greater peak heights and maximum slopes than plumes from point sources, thus providing a significantly different exposure paradigm. This quantification of how chemicals move differently throughout a fluid medium when introduced from point and nonpoint sources allows a greater understanding of how chemical plumes can potentially affect aquatic ecosystems.

  7. Electrochemical treatment of the effluent of a fine chemical manufacturing plant.

    PubMed

    Cañizares, P; Paz, R; Lobato, J; Sáez, C; Rodrigo, M A

    2006-11-02

    In this work, the electrochemical oxidation of an actual industrial wastewater with conductive-diamond anodes has been studied. The wastewater is the effluent of a fine chemicals plant. This effluent consists of an aqueous solution of solvents (ketones and alcohols) with a high concentration of aromatic compounds coming from the raw materials, intermediates and products of the different processes of the plant and its COD is around 6000 mg dm(-3). The electrolyses were carried out in a discontinuous operation mode under galvanostatic conditions, using a bench-scale plant equipped with a single compartment electrochemical flow cell. The conductive-diamond electrochemical oxidation (CDEO) allowed achieving the complete mineralization of the waste with high current efficiencies. These efficiencies seem to strongly depend on the concentration, pH and temperature but not on the current density (in the range studied). This confirms that besides the hydroxyl radicals mediated oxidation, CDEO combines other important oxidation processes such as the direct electrooxidation on the diamond surface and the oxidation mediated by other electrochemically formed compounds generated on this electrode. Other two advanced oxidation processes (ozonation and Fenton oxidation) have been also studied in this work for comparison purposes. Both technologies were able to treat the wastes, but they obtained very different results in terms of efficiency and mineralization. The efficiency of ozonation and electrochemical oxidation were very similar (especially during the first stages), although the energy consumption required by the electrochemical process to remove at fixed percentage of COD or TOC was significantly smaller than that of ozonation. The possible accumulation of carboxylic acid as final products excludes the use of Fenton oxidation as a sole treatment technology.

  8. Impact of chemical leaching on permeability and cadmium removal from fine-grained soils.

    PubMed

    Lin, Zhongbing; Zhang, Renduo; Huang, Shuang; Wang, Kang

    2017-06-21

    The aim of this study was to investigate the influence of chemical leaching on permeability and Cd removal from fine-grained polluted soils. Column leaching experiments were conducted using two types of soils (i.e., artificially Cd-polluted loam and historically polluted silty loam). Chemical agents of CaCl2, FeCl3, citric acid, EDTA, rhamnolipid, and deionized water were used to leach Cd from the soils. Results showed that organic agents reduced permeability of both soils, and FeCl3 reduced permeability of loam soil, compared with inorganic agents and deionized water. Entrapment and deposition of colloids generated from the organic agents and FeCl3 treatments reduced the soil permeability. The peak Cd effluence from the artificially polluted loam columns was retarded. For the artificially polluted soils treated with EDTA and the historically polluted soils with FeCl3, Cd precipitates were observed at the bottom after chemical leaching. When Cd was associated with large colloid particles, the reduction of soil permeability caused Cd accumulation in deeper soil. In addition, the slow process of disintegration of soil clay during chemical leaching might result in the retardation of peak Cd effluence. These results suggest the need for caution when using chemical-leaching agents for Cd removal in fine-grained soils.

  9. Chemical speciation and source apportionment of fine particulate matter in Santiago, Chile, 2013.

    PubMed

    Villalobos, Ana M; Barraza, Francisco; Jorquera, Héctor; Schauer, James J

    2015-04-15

    Santiago is one of the largest cities in South America and has experienced high fine particulate matter (PM2.5) concentrations in fall and winter months for decades. To better understand the sources of fall and wintertime pollution in Santiago, PM2.5 samples were collected for 24 h every weekday from March to October 2013 for chemical analysis. Samples were analyzed for mass, elemental carbon (EC), organic carbon (OC), water soluble organic carbon (WSOC), water soluble nitrogen (WSTN), secondary inorganic ions, and particle-phase organic tracers for source apportionment. Selected samples were analyzed as monthly composites for organic tracers. PM2.5 concentrations were considerably higher in the coldest months (June-July), averaging (mean ± standard deviation) 62±15 μg/m(3) in these two months. Average fine particle mass concentration during the study period was 40±20 μg/m(3). Organic matter during the peak winter months was the major component of fine particles comprising around 70% of the particle mass. Source contributions to OC were calculated using organic molecular markers and a chemical mass balance (CMB) receptor model. The four combustion sources identified were wood smoke, diesel engine emission, gasoline vehicles, and natural gas. Wood smoke was the predominant source of OC, accounting for 58±42% of OC in fall and winter. Wood smoke and nitrate were the major contributors to PM2.5. In fall and winter, wood smoke accounted for 9.8±7.1 μg/m(3) (21±15%) and nitrate accounted for 9.1±4.8 μg/m(3) (20±10%) of fine PM. The sum of secondary inorganic ions (sulfate, nitrate, and ammonium) represented about 30% of PM2.5 mass. Secondary organic aerosols contributed only in warm months, accounting for about 30% of fine PM during this time. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Spontaneous fine-tuning to environment in many-species chemical reaction networks

    NASA Astrophysics Data System (ADS)

    Horowitz, Jordan M.; England, Jeremy L.

    2017-07-01

    A chemical mixture that continually absorbs work from its environment may exhibit steady-state chemical concentrations that deviate from their equilibrium values. Such behavior is particularly interesting in a scenario where the environmental work sources are relatively difficult to access, so that only the proper orchestration of many distinct catalytic actors can power the dissipative flux required to maintain a stable, far-from-equilibrium steady state. In this article, we study the dynamics of an in silico chemical network with random connectivity in an environment that makes strong thermodynamic forcing available only to rare combinations of chemical concentrations. We find that the long-time dynamics of such systems are biased toward states that exhibit a fine-tuned extremization of environmental forcing.

  11. Spontaneous fine-tuning to environment in many-species chemical reaction networks.

    PubMed

    Horowitz, Jordan M; England, Jeremy L

    2017-07-18

    A chemical mixture that continually absorbs work from its environment may exhibit steady-state chemical concentrations that deviate from their equilibrium values. Such behavior is particularly interesting in a scenario where the environmental work sources are relatively difficult to access, so that only the proper orchestration of many distinct catalytic actors can power the dissipative flux required to maintain a stable, far-from-equilibrium steady state. In this article, we study the dynamics of an in silico chemical network with random connectivity in an environment that makes strong thermodynamic forcing available only to rare combinations of chemical concentrations. We find that the long-time dynamics of such systems are biased toward states that exhibit a fine-tuned extremization of environmental forcing.

  12. Co-production of microbial polyhydroxyalkanoates with other chemicals.

    PubMed

    Li, Tian; Elhadi, Dina; Chen, Guo-Qiang

    2017-09-01

    Engineering microorganisms capable of simultaneously accumulating multiple products are economically attractive for biotechnology. Polyhydroxyalkanoates (PHA) or microbial bioplastics are promising as biodegradable plastics to address environmental concerns resulted from plastic wastes accumulation. Unfortunately, PHA production is still limited and cannot compete with the chemically synthesized plastics due to their high production cost. Efforts have been devoted to reduce PHA production cost by employing PHA co-production with other valuable chemicals. Successful co-productions of PHA have been demonstrated with amino acids, proteins, alcohols, hydrogen, biosurfactants, exopolysaccharides and several fine chemicals. The strategy allows recovering PHA from the cells and other value-added products from the no-cells broths. Numerous successful strategies have been developed for minimizing the substrate cost and improving the product yields. This paper reviews the recent strategies developed in PHA co-production with other compounds, discusses the challenges and prospective during the scale up of the co-production strategies. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  13. Nitridation of fine grain chemical vapor deposited tungsten film as diffusion barrier for aluminum metallization

    NASA Astrophysics Data System (ADS)

    Chang, Kow-Ming; Yeh, Ta-Hsun; Deng, I.-Chung

    1997-04-01

    A novel tungsten nitride (WNx) film for diffusion barrier applications has been prepared by nitridation of a fine grain chemical vapor deposited tungsten (CVD-W) film. The fine grain CVD-W is deposited at 300 °C in a low pressure chemical vapor deposition reactor with a SiH4/WF6 flow rate of 12.5/5 sccm under a total gas pressure of 100 mTorr. The subsequent nitridation process is executed in nitrogen plasma at 300 °C without breaking vacuum. The thickness of WNx layer as examined by secondary ion mass spectroscopy is 50 nm after 5 min exposure to nitrogen plasma. X-ray photoelectron spectroscopy spectra shows that the atomic ratio of tungsten to nitrogen in WNx layer is 2:1. According to the analysis by Auger electron spectroscopy and the measurement of n+p junction leakage current, the Al/WNx/W/Si multilayer maintains excellent interfacial stability after furnace annealing at 575 °C for 30 min. The effectiveness of W2N barrier is attributed to stuffing grain boundaries with nitrogen atoms which eliminates the rapid diffusion paths in fine grain CVD-W films.

  14. Nitridation of fine grain chemical vapor deposited tungsten film as diffusion barrier for aluminum metallization

    SciTech Connect

    Chang, K.; Yeh, T.; Deng, I.

    1997-04-01

    A novel tungsten nitride (WN{sub x}) film for diffusion barrier applications has been prepared by nitridation of a fine grain chemical vapor deposited tungsten (CVD-W) film. The fine grain CVD-W is deposited at 300{degree}C in a low pressure chemical vapor deposition reactor with a SiH{sub 4}/WF{sub 6} flow rate of 12.5/5 sccm under a total gas pressure of 100 mTorr. The subsequent nitridation process is executed in nitrogen plasma at 300{degree}C without breaking vacuum. The thickness of WN{sub x} layer as examined by secondary ion mass spectroscopy is 50 nm after 5 min exposure to nitrogen plasma. X-ray photoelectron spectroscopy spectra shows that the atomic ratio of tungsten to nitrogen in WN{sub x} layer is 2:1. According to the analysis by Auger electron spectroscopy and the measurement of n{sup +}p junction leakage current, the Al/WN{sub x}/W/Si multilayer maintains excellent interfacial stability after furnace annealing at 575{degree}C for 30 min. The effectiveness of W{sub 2}N barrier is attributed to stuffing grain boundaries with nitrogen atoms which eliminates the rapid diffusion paths in fine grain CVD-W films. {copyright} {ital 1997 American Institute of Physics.}

  15. Mercury transformations in chemical agent simulant as characterized by X-ray absorption fine spectroscopy.

    PubMed

    Skubal, Laura R; Biedron, Sandra G; Newville, Matthew; Schneider, John F; Milton, Stephen V; Pianetta, Piero; O'Neill, H Jack

    2005-10-15

    Chemical analyses of U.S. stockpiled mustard chemical warfare agent show some agent destined for destruction contains mercury [L. Ember, Chem. Eng. News 82 (2004) 8]. Because of its toxicity, mercury must be removed from agent prior to incineration or be scrubbed from incineration exhaust to prevent release into the atmosphere. Understanding mercury/agent interactions is critical if either atmospheric or aqueous treatment processes are used. We investigate and compare the state of mercury in water to that in thiodiglycol, a mustard simulant, as co-contaminants are introduced. The effects of sodium hypochlorite and sodium hydroxide, common neutralization chemicals, on mercury in water and simulant with and without co-contaminants present are examined using X-ray absorption fine spectroscopy (XAFS).

  16. Suspect Screening of Chemicals in Consumer Products

    EPA Science Inventory

    This presentation details a pilot suspect screening analysis (SSA) of common consumer products done under the Rapid Exposure and Dosimetry project of CSS. This work presents methods which can rapidly characterize chemicals identified in consumer products including formulations (s...

  17. EFFECTS OF CO2 AND TEMPERATURE ON FINE ROOT PRODUCTION AND MORTALITY IN DOUGLAS FIR

    EPA Science Inventory

    Little is known about the effects of global climate change on the production and mortality of fine roots. We conducted a 4-year study to determine the effects of elevated CO2 and temperature on Douglas fir fine ( 2 mm in diameter) roots. The study was conducted in sun-lit cont...

  18. Nonlinear dendritic integration of electrical and chemical synaptic inputs drives fine-scale correlations

    PubMed Central

    Trenholm, Stuart; McLaughlin, Amanda J; Schwab, David J; Turner, Maxwell H; Smith, Robert G; Rieke, Fred; Awatramani, Gautam B

    2014-01-01

    Throughout the CNS, gap junction–mediated electrical signals synchronize neural activity on millisecond timescales via cooperative interactions with chemical synapses. However, gap junction–mediated synchrony has rarely been studied in the context of varying spatiotemporal patterns of electrical and chemical synaptic activity. Thus, the mechanism underlying fine-scale synchrony and its relationship to neural coding remain unclear. We examined spike synchrony in pairs of genetically identified, electrically coupled ganglion cells in mouse retina. We found that coincident electrical and chemical synaptic inputs, but not electrical inputs alone, elicited synchronized dendritic spikes in subregions of coupled dendritic trees. The resulting nonlinear integration produced fine-scale synchrony in the cells’ spike output, specifically for light stimuli driving input to the regions of dendritic overlap. In addition, the strength of synchrony varied inversely with spike rate. Together, these features may allow synchronized activity to encode information about the spatial distribution of light that is ambiguous on the basis of spike rate alone. PMID:25344631

  19. The effect of tree species diversity on fine-root production in a young temperate forest.

    PubMed

    Lei, Pifeng; Scherer-Lorenzen, Michael; Bauhus, Jürgen

    2012-08-01

    The phenomenon of overyielding in species-diverse plant communities is mainly attributed to complementary resource use. Vertical niche differentiation belowground might be one potential mechanism for such complementarity. However, most studies that have analysed the diversity/productivity relationship and belowground niche differentiation have done so for fully occupied sites, not very young tree communities that are in the process of occupying belowground space. Here we used a 5–6 year old forest diversity experiment to analyse how fine-root (<2 mm) production in ingrowth cores (0–30 cm) was influenced by tree species identity, as well as the species diversity and richness of tree neighbourhoods. Fine-root production during the first growing season after the installation of ingrowth cores increased slightly with tree species diversity, and four-species combinations produced on average 94.8% more fine-root biomass than monocultures. During the second growing season, fine-root mortality increased with tree species diversity, indicating an increased fine-root turnover in species-rich communities. The initial overyielding was attributable to the response to mixing by the dominant species, Pseudotsuga menziesii and Picea abies, which produced more fine roots in mixtures than could be expected from monocultures. In species-rich neighbourhoods, P. abies allocated more fine roots to the upper soil layer (0–15 cm), whereas P. menziesii produced more fine roots in the deeper layer (15–30 cm) than in species-poor neighbourhoods. Our results indicate that, although there may be no lasting overyielding in the fine-root production of species-diverse tree communities, increasing species diversity can lead to substantial changes in the production, vertical distribution, and turnover of fine roots of individual species.

  20. Ecological effects and chemical composition of fine sediments in Upper Austrian streams and resulting implications for river management

    NASA Astrophysics Data System (ADS)

    Höfler, Sarah; Pichler-Scheder, Christian; Gumpinger, Clemens

    2017-04-01

    In the current scientific discussion high loads of fine sediments are considered one of the most important causes of river ecosystem degradation worldwide. Especially in intensively used catchment areas changes in the sediment household must be regarded as a reason, which prevents the achievement of the objectives of the European Water Framework Directive (WFD). Therefore, the Upper Austrian Water Authorities have launched two comprehensive studies on the topic. The first one was a survey on the current siltation status of river courses in Upper Austria. The second study deals with two selected catchments in detail, in order to get a clear picture of the impacts of the fines on the aquatic fauna (trout eggs, benthic invertebrates), the chemical composition of these fractions, the crucial hydrogeological processes and to develop possible role models for measures both in the catchments and in the streams. At eight sites within the two catchments sediment and water samples were collected at two dates for detailed chemical analysis. On one date additionally the benthic invertebrate fauna was investigated on the microhabitat level. Thereby it was possible to enhance the understanding of the range of ecological impacts caused by silting-up in different hydro-morphological circumstances and with different fine sediment loads. The water samples as well as the sediment fraction samples <0.063 mm were examined for different metals, organochlorine pesticides, PAHs (Polycyclic Aromatic Hydrocarbons), PCBs (Polychlorinated biphenyls), BTEX (benzene, toluene, ethylbenzene, and xylenes), AOX (adsorbable organohalogens) and various nutrients. Additionally, the basic parameters dry residue, loss on ignition, TC (total carbon), TOC (total organic carbon) and nutrients were analysed. From the sediment eluates and the filtered water decomposition products of pesticides, remains of medical drugs, sweeteners, hormonally active substances and water-soluble elements were analysed

  1. Seasonal trends, chemical speciation and source apportionment of fine PM in Tehran

    NASA Astrophysics Data System (ADS)

    Arhami, Mohammad; Hosseini, Vahid; Zare Shahne, Maryam; Bigdeli, Mostafa; Lai, Alexandra; Schauer, James J.

    2017-03-01

    Frequent air pollution episodes have been reported for Tehran, Iran, mainly because of critically high levels of fine particulate matter (PM2.5). The composition and sources of these particles are poorly known, so this study aims to identify the major components and heavy metals in PM2.5 along with their seasonal trends and associated sources. 24-hour PM2.5 samples were collected at a main residential station every 6 days for a full year from February 2014 to February 2015. The samples were analyzed for ions, organic carbon (including water-soluble and insoluble portions), elemental carbon (EC), and all detectable elements. The dominant mass components, which were determined by means of chemical mass closure, were organic matter (35%), dust (25%), non-sea salt sulfate (11%), EC (9%), ammonium (5%), and nitrate (2%). Organic matter and EC together comprised 44% of fine PM on average (increased to >70% in the colder season), which reflects the significance of anthropogenic urban sources (i.e. vehicles). The contributions of different components varied considerably throughout the year, particularly the dust component that varied from 7% in the cold season to 56% in the hot and dry season. Principal component analyses were applied, resulting in 5 major source factors that explained 85% of the variance in fine PM. Factor 1, representing soil dust, explained 53%; Factor 2 denotes heavy metals mainly found in industrial sources and accounted for 18%; and rest of factors, mainly representing combustion sources, explained 14% of the variation. The levels of major heavy metals were further evaluated, and their trends showed considerable increases during cold seasons. The results of this study provide useful insight to fine PM in Tehran, which could help in identifying their health effects and sources, and also adopting effective control strategies.

  2. Tailor-made biocatalysts enzymes for the fine chemical industry in China.

    PubMed

    Jiang, Yu; Tao, Rongsheng; Yang, Sheng

    2016-09-01

    The Center of Industrial Biotechnology (CIBT) was established in Huzhou for fine chemicals in 2006 and CIBT Shanghai was founded for bulk chemicals in 2008. CIBT is a non-profit organization under auspices of the Shanghai Institutes for Biological Sciences, Shanghai Branch of the Chinese Academy of Sciences (CAS) and Huzhou Municipal Government. CIBT is affiliated with the CAS, which enables it to take advantage of the rich R&D resources and support from CAS; yet CIBT operates as an independent legal entity. The goal of CIBT is to incubate industrial biotechnologies and accelerate the commercialization of these technologies with corporate partners in China. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Indirect quantification of fine root production in a near tropical wet mountainous region

    NASA Astrophysics Data System (ADS)

    Lu, X.; Zhang, J.; Huang, C.

    2016-12-01

    The main functions of fine root (defined as diameter <= 2 mm) are water and nutrient transports. Besides being a carbon (C) storage pool, it also provides a C flux pathway through soil and plant. Fine root takes up a small portion, normally 5%, of biomass in forest ecosystems, but 30% to 70% of total net primary production. Therefore, quantifying fine root productivity is important to study the forest C budget. Presumably, belowground growth can be indirectly estimated by the more accessible aboveground vegetation structure dynamics. To verify the relationship with fine root productivity, we take internal (floristic) and external (environmental) factors into account, including litter production, canopy density (leaf area index), leaf nutrients (N, K, Ca, Mg, P), weather and/or soil physical conditions (air temperature, humidity, precipitation, solar radiation and soil moisture). The study was conducted in near tropical broadleaf (700 m asl) and conifer (1700 m asl) forests in northeastern Taiwan, generally receiving more than 4000 mm of precipitation per year. For each site, 16 50-cm long minirhizotron tubes were installed. Fine root images were acquired every three weeks. Growth and decline, newly presence and absence of fine roots were delineated by image processing algorithms to derive fine-root productivity through time. Aforementioned internal and external attributes were simultaneously collected as well. Some of these variables were highly correlated and were detrended using principal component analysis. We found that these transformed variables (mainly associated with litter production, precipitation and solar radiation) can delineate the spatiotemporal dynamics of root production well (r2 = 0.87, p = 0.443). In conclusion, this study demonstrated the feasibility of utilized aboveground variables to indirectly assess fine root growth, which could be further developed for the regional scale mapping with aid of remote sensing.

  4. Characterization of Fine Particulate Matter and Associations between Particulate Chemical Constituents and Mortality in Seoul, Korea

    PubMed Central

    Son, Ji-Young; Lee, Jong-Tae; Kim, Ki-Hyun; Jung, Kweon

    2012-01-01

    Background: Numerous studies have linked fine particles [≤ 2.5 µm in aerodynamic diameter (PM2.5)] and health. Most studies focused on the total mass of the particles, although the chemical composition of the particles varies substantially. Which chemical components of fine particles that are the most harmful is not well understood, and research on the chemical composition of PM2.5 and the components that are the most harmful is particularly limited in Asia. Objectives: We characterized PM2.5 chemical composition and estimated the effects of cause-specific mortality of PM2.5 mass and constituents in Seoul, Korea. We compared the chemical composition of particles to those of the eastern and western United States. Methods: We examined temporal variability of PM2.5 mass and its composition using hourly data. We applied an overdispersed Poisson generalized linear model, adjusting for time, day of week, temperature, and relative humidity to investigate the association between risk of mortality and PM2.5 mass and its constituents in Seoul, Korea, for August 2008 through October 2009. Results: PM2.5 and chemical components exhibited temporal patterns by time of day and season. The chemical characteristics of Seoul’s PM2.5 were more similar to PM2.5 found in the western United States than in the eastern United States. Seoul’s PM2.5 had lower sulfate (SO4) contributions and higher nitrate (NO3) contributions than that of the eastern United States, although overall PM2.5 levels in Seoul were higher than in the United States. An interquartile range (IQR) increase in magnesium (Mg) (0.05 μg/m3) was associated with a 1.4% increase (95% confidence interval: 0.2%, 2.6%) in total mortality on the following day. Several components that were among the largest contributors to PM2.5 total mass—NO3, SO4, and ammonium (NH4)—were moderately associated with same-day cardiovascular mortality at the p < 0.10 level. Other components with smaller mass contributions [Mg and

  5. Advancing Consumer Product Composition and Chemical ...

    EPA Pesticide Factsheets

    This presentation describes EPA efforts to collect, model, and measure publically available consumer product data for use in exposure assessment. The development of the ORD Chemicals and Products database will be described, as will machine-learning based models for predicting chemical function. Finally, the talk describes new mass spectrometry-based methods for measuring chemicals in formulation and articles. This presentation is an invited talk to the ICCA-LRI workshop "Fit-For-Purpose Exposure Assessments For Risk-Based Decision Making". The talk will share EPA efforts to characterize the components of consumer products for use in exposure assessment with the international exposure science community.

  6. [Fine root production and turnover in Pinus massoniana plantation in Three Gorges Reservoir area of China].

    PubMed

    Wang, Rui-Li; Cheng, Rui-Mei; Xiao, Wen-Fa; Feng, Xiao-Hui; Liu, Ze-Bin; Ge, Xiao-Gai; Wang, Xiao-Rong; Zhang, Wei-Yin

    2012-09-01

    By the methods of sequential soil cores and buried bags, an investigation was conducted to study the seasonal dynamics of fine roots in a 20-year-old Pinus massoniana plantation in Three Gorges Reservoir Area from March to December 2011, with the annual production and turnover rate of the fine roots calculated. In the plantation, the annual mean biomass of <2 mm fine roots was 146.98 g x m(-2) x a(-1), in which, the living root biomass (102.92 g x m(-2) x a(-1)) was far greater than that of the dead root biomass (44.06 g x m(-2) x a(-1)). Among the fine roots with different sizes, <1 mm fine roots had an obvious seasonal dynamics in their biomass, showing a unimodal curve in the sampling period. The annual production and turnover rate of <2 mm fine roots were 104. 12 g x m(-2) x 1(-1) and 1.05 a(-1), respectively, in which, the annual production of <1 mm and 1-2 mm fine roots was 58.35 and 45.77 g x m(-2) x a(-1), and the turnover rate was 1.41 and 0.69 a(-1), respectively.

  7. [Fine root biomass and production of four vegetation types in Loess Plateau, China].

    PubMed

    Deng, Qiang; Li, Ting; Yuan, Zhi-You; Jiao, Feng

    2014-11-01

    Fine roots (≤ 2 mm) play a major role in biogeochemical cycling in ecosystems. By the methods of soil cores and ingrowth soil cores, we studied the biomass and annual production of fine roots in 0-40 cm soil layers of four main vegetation types, i. e. , Robinia pseudoacacia plantation, deciduous shrubs, abandoned grassland, and Artemisia desertorum community in Loess Plateau, China. The spatial patterns of fine root biomass and production were negatively associated with latitudes. The fine root biomass in the 0-40 cm soil layer was in the order of deciduous shrubs (220 g · m(-2)), R. pseudoacacia plantation (163 g · m(-2)), abandoned grassland (162 g · m(-2)) and A. desertorum community (79 g · m(-2)). The proportion of ≤ 1 mm fine root biomass (74.1%) in the 0-40 cm soil layer of abandoned grassland was significantly higher than those in the other three vegetation types. The fine root biomass of the four vegetation types was mainly distributed in the 0-10 cm soil layer and decreased with soil depth. The proportion of fine root biomass (44.1%) in the 0-10 cm soil layer of abandoned grassland was significantly higher than those in other three vegetation types. The fine root productions of four vegetation types were in the order of abandoned grassland (315 g · m(-2) · a(-1)) > deciduous shrubs (249 g · m(-2) a(-1)) > R. pseudoacacia plantation (219 g · m(-2) · a(-1)) > A. desertorum community (115 g · m(-2) · a(-1)), and mainly concentrated in the 0-10 cm top soil layer and decreased with the soil depth. The proportion of the annual production (40.4%) in the 0-10 cm soil layer was the highest in abandoned grassland. Fine roots of abandoned grassland turned over faster than those from the other three vegetation types.

  8. Global Chemical Composition of Ambient Fine Particulate Matter for Exposure Assessment

    DOE PAGES

    Philip, Sajeev; Martin, Randall V.; van Donkelaar, Aaron; ...

    2014-10-24

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004–2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrationsmore » were dominated by particulate organic mass (11.9 ± 7.3 μg/m3), secondary inorganic aerosol (11.1 ± 5.0 μg/m3), and mineral dust (11.1 ± 7.9 μg/m3). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m3 over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m3) could be almost as large as from fossil fuel combustion sources (17 μg/m3). In conclusion, these estimates offer information about global population exposure to the chemical components and sources of PM2.5.« less

  9. Global Chemical Composition of Ambient Fine Particulate Matter for Exposure Assessment

    PubMed Central

    2015-01-01

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004–2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrations were dominated by particulate organic mass (11.9 ± 7.3 μg/m3), secondary inorganic aerosol (11.1 ± 5.0 μg/m3), and mineral dust (11.1 ± 7.9 μg/m3). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m3 over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m3) could be almost as large as from fossil fuel combustion sources (17 μg/m3). These estimates offer information about global population exposure to the chemical components and sources of PM2.5. PMID:25343705

  10. EFFECTS OF CHEMICAL DISPERSANTS AND MINERAL FINES ON CRUDE OIL DISPERSION IN A WAVE TANK UNDER BREAKING WAVES

    EPA Science Inventory

    The interaction of chemical dispersants and suspended sediments with crude oil influences the fate and transport of oil spills in coastal waters. A wave tank study was conducted to investigate the effects of chemical dispersants and mineral fines on the dispersion of oil and the ...

  11. EFFECTS OF CHEMICAL DISPERSANTS AND MINERAL FINES ON CRUDE OIL DISPERSION IN A WAVE TANK UNDER BREAKING WAVES

    EPA Science Inventory

    The interaction of chemical dispersants and suspended sediments with crude oil influences the fate and transport of oil spills in coastal waters. A wave tank study was conducted to investigate the effects of chemical dispersants and mineral fines on the dispersion of oil and the ...

  12. Production of hydroxyl radicals from Fe-containing fine particles in Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Ma, Shexia; Ren, Ke; Liu, Xiaowen; Chen, Laiguo; Li, Mei; Li, Xiaoying; Yang, Jian; Huang, Bo; Zheng, Mei; Xu, Zhencheng

    2015-12-01

    Reactive oxygen species (ROS) production from ambient fine particles has been correlated with the soluble transition metal content of PM2.5, which also has clear association with particle-mediated cardiopulmonary toxicity. Hydroxyl radical (rad OH) is the most harmful ROS species through chemical reactions of redox-active particle components. Atmospheric Fe, as the dominant species of the transition metals in the atmosphere, is associated with rad OH generation in ambient particle extracts. Our results revealed that Fe-containing particles (18,730 in total number) contributed approximately 3.7% on average to all detected particles throughout the summer and winter sampling period in Guangzhou, which was clustered into four distinct particle classes, including Fe-rich, Metal-rich, NaK-rich and Dust-rich. Fe-rich class was the dominant one with a fraction of 61%, followed by Dust-rich (14%), Metal-rich (13%). and NaK-rich (12%). The iron oxide was enriched in the Fe-rich class. rad OH generation induced by Fe-containing fine particles collected in Guangzhou (GZ) was quantified in a surrogate lung fluid (SLF), and it was found that Fe-containing fine particles were generally much reactive in generating rad OH in the presence of four antioxidants (200 μM ascorbate, 300 μM citrate, 100 μM reduced L-glutathione, and 100 μM uric acid). The annual average rad OH amount produced in our samples was 132.98 ± 27.43 nmol rad OH mg-1 PM2.5. rad OH production had a clear seasonal pattern with higher amount in summer and lower in winter. By measuring the amount of total and SLF-soluble metal in our PM2.5 samples using ICP-MS, we found that ROS activities were associated with the ionizable Fe through Fenton type reactions in the Guangzhou PM2.5. Expected burdens of PM2.5 derived rad OH in human lung lining fluid suggests that typical daily particulate matter exposure in Guangzhou is already a concern, and it could produce much higher levels of rad OH, leading to higher

  13. Production of chemicals and fuels from biomass

    DOEpatents

    Woods, Elizabeth; Qiao, Ming; Myren, Paul; Cortright, Randy D.; Kania, John

    2015-12-15

    Described are methods, reactor systems, and catalysts for converting biomass to fuels and chemicals in a batch and/or continuous process. The process generally involves the conversion of water insoluble components of biomass, such as hemicellulose, cellulose and lignin, to volatile C.sub.2+O.sub.1-2 oxygenates, such as alcohols, ketones, cyclic ethers, esters, carboxylic acids, aldehydes, and mixtures thereof. In certain applications, the volatile C.sub.2+O.sub.1-2 oxygenates can be collected and used as a final chemical product, or used in downstream processes to produce liquid fuels, chemicals and other products.

  14. Chemical characteristics of fine particles emitted from different gas cooking methods

    NASA Astrophysics Data System (ADS)

    See, Siao Wei; Balasubramanian, Rajasekhar

    Gas cooking is an important indoor source of fine particles (PM 2.5). The chemical characteristics of PM 2.5 emitted from different cooking methods, namely, steaming, boiling, stir-frying, pan-frying and deep-frying were investigated in a domestic kitchen. Controlled experiments were conducted to measure the mass concentration of PM 2.5 and its chemical constituents (elemental carbon (EC), organic carbon (OC), polycyclic aromatic hydrocarbons (PAHs), metals and ions) arising from these five cooking methods. To investigate the difference in particle properties of different cooking emissions, the amount and type of food, and the heat setting on the gas stove were kept constant during the entire course of the experiments. Results showed that deep-frying gave rise to the largest amount of PM 2.5 and most chemical components, followed by pan-frying, stir-frying, boiling, and steaming. Oil-based cooking methods released more organic pollutants (OC, PAHs, and organic ions) and metals, while water-based cooking methods accounted for more water-soluble (WS) ions. Their source profiles are also presented and discussed.

  15. Chemicals in household products: problems with solutions.

    PubMed

    Glegg, Gillian A; Richards, Jonathan P

    2007-12-01

    The success of a regulatory regime in decreasing point-source emissions of some harmful chemicals has highlighted the significance of other sources. A growing number of potentially harmful chemicals have been incorporated into an expanding range of domestic household products and are sold worldwide. Tighter regulation has been proposed, and the European Commission has introduced the Regulation on the Registration, Evaluation, and Authorisation of Chemicals to address this concern. However, it is clear that in addition to the regulation, there is a potential to effect change through retailer and consumer attitudes and behaviours. Interviews were conducted with 7 key stakeholder groups to identify critical issues, which were then explored using a public survey questionnaire (1,008 respondents) and 8 subsequent focus groups. The findings demonstrated that the issue of chemicals in products is of concern to consumers for reasons of personal health rather than environmental protection. Key obstacles to the wider purchase of "green-alternative" products included perceived high cost and poor performance, lack of availability of products, and poor information concerning such products. Although improved regulation was seen as part of the solution, consumers must also play a role. It was clear from this study that consumers are not currently able to make informed choices about the chemicals they use but that they would be receptive to moving toward a more sustainable use of chemicals in the future if empowered to do so.

  16. Contrasting fine-root production, survival and soil CO2 efflux in pine and poplar plantation

    Treesearch

    M. D. Coleman; Richard E. Dickson; J. G. Isebrands

    2000-01-01

    Tree root activity, including fine-root production, turnover and metabolic activity are significant components of forest productivity and nutrient cycling. Differences in root activity among forest types are not well known. A 3-year study was undertaken in red pine (Pinus resinosa Ait.) and hybrid poplar (Populus tristis X P.

  17. Contrasting fine-root production, survival and soil CO2 efflux in pine and poplar plantations

    Treesearch

    M.D. Coleman; R.E. Dickson; J.G. Isebrands

    2000-01-01

    Tree root activity, including fine-root production, turnover and metabolic activity are significant components of forest productivity and nutrient cycling. Differences in root activity among forest types are not well known. A 3-year study was undertaken in red pine (Pinus resinosa Ait.) and hybrid poplar (Populus tristis X P.

  18. Chemical production processes and systems

    DOEpatents

    Holladay, Johnathan E.; Muzatko, Danielle S.; White, James F.; Zacher, Alan H.

    2014-06-17

    Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.

  19. Chemical production processes and systems

    DOEpatents

    Holladay, Johnathan E; Muzatko, Danielle S; White, James F; Zacher, Alan H

    2015-04-21

    Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.

  20. Engineering microbes for efficient production of chemicals

    DOEpatents

    Gong, Wei; Dole, Sudhanshu; Grabar, Tammy; Collard, Andrew Christopher; Pero, Janice G; Yocum, R Rogers

    2015-04-28

    This present invention relates to production of chemicals from microorganisms that have been genetically engineered and metabolically evolved. Improvements in chemical production have been established, and particular mutations that lead to those improvements have been identified. Specific examples are given in the identification of mutations that occurred during the metabolic evolution of a bacterial strain genetically engineered to produce succinic acid. This present invention also provides a method for evaluating the industrial applicability of mutations that were selected during the metabolic evolution for increased succinic acid production. This present invention further provides microorganisms engineered to have mutations that are selected during metabolic evolution and contribute to improved production of succinic acid, other organic acids and other chemicals of commercial interest.

  1. Global Chemical Composition of Ambient Fine Particulate Matter for Exposure Assessment

    SciTech Connect

    Philip, Sajeev; Martin, Randall V.; van Donkelaar, Aaron; Lo, Jason Wai-Ho; Wang, Yuxuan; Chen, Dan; Zhang, Lin; Kasibhatla, Prasad S.; Wang, Siwen; Zhang, Qiang; Lu, Zifeng; Streets, David G.; Bittman, Shabtai; Macdonald, Douglas J.

    2014-10-24

    Epidemiologic and health impact studies are inhibited by the paucity of global, long-term measurements of the chemical composition of fine particulate matter. We inferred PM2.5 chemical composition at 0.1° × 0.1° spatial resolution for 2004–2008 by combining aerosol optical depth retrieved from the MODIS and MISR satellite instruments, with coincident profile and composition information from the GEOS-Chem global chemical transport model. Evaluation of the satellite-model PM2.5 composition data set with North American in situ measurements indicated significant spatial agreement for secondary inorganic aerosol, particulate organic mass, black carbon, mineral dust, and sea salt. We found that global population-weighted PM2.5 concentrations were dominated by particulate organic mass (11.9 ± 7.3 μg/m3), secondary inorganic aerosol (11.1 ± 5.0 μg/m3), and mineral dust (11.1 ± 7.9 μg/m3). Secondary inorganic PM2.5 concentrations exceeded 30 μg/m3 over East China. Sensitivity simulations suggested that population-weighted ambient PM2.5 from biofuel burning (11 μg/m3) could be almost as large as from fossil fuel combustion sources (17 μg/m3). In conclusion, these estimates offer information about global population exposure to the chemical components and sources of PM2.5.

  2. Researchers fine-tune production of energy crops

    SciTech Connect

    Parish, D.J. )

    1990-04-01

    Renewable energy sources, plant materials that can be processed into liquid fuels, are becoming increasingly important as fossil fuel sources dwindle and environmental impacts of releasing fossilized carbon into the atmosphere become more evident. But which plant species provide the most material and can be grown on land not used to produce food, feed, and fiber Switchgrass exceeds all other herbaceous species we have tested in production of biomass on marginal sites in the Virginia Piedmont reports David J. Parrish, Virginia Tech (Blacksburg, VA) professor of crop and soil environmental sciences. In a study sponsored by the U.S. Department of Energy (DOE) at Virginia Tech, graduate student Steven Nagle, Parrish, professor Dale Wolf, and associate professor W.L. Daniels are comparing the biomass productivity of switchgrass, weeping lovegrass, and tall fescue. Since 1985, the crops - selected for their marginal crop value - have been grown on 12 sites in the Virginia Piedmont. Planting was done using no-till procedures that slice but do not turn the soil, because the sites are subject to erosion. The two warm-season grasses are harvested once a year, the fescue twice. Switchgrass has been the most productive on clay soils, and lovegrass on sandy soil. In a second DOE-sponsored study - this one by graduate student Preston Sullivan, Parish, Wolf, Daniels, and Nagle - the Virginia Tech researchers have begun to investigate planting winter-annual legumes in with switchgrass as a source of nitrogen to reduce cost of production, and as a means to increase biomass. In the fall of 1988, crimson clover, arrowleaf clover, and hairy vetch were planted into the switchgrass stubble. Other plots of switchgrass are being provided with various levels of nitrogen fertilizer to compare those yields with legume-planted plots. Crimson clover had provided the most fall growth, but by mid-May 1989, the hairy vetch had produced a dense webbing of biomass over the new switchgrass.

  3. Calculation procedures to estimate fine root production rates in forests using two-dimensional fine root data obtained by the net sheet method.

    PubMed

    Noguchi, Kyotaro; Tanikawa, Toko; Inagaki, Yoshiyuki; Ishizuka, Shigehiro

    2017-06-01

    Several recent studies have used the net sheet method to estimate fine root production rates in forest ecosystems, wherein net sheets are inserted into the soil and fine roots growing through them are observed. Although this method has advantages in terms of its easy handling and low cost, there are uncertainties in the estimates per unit soil volume or unit stand area, because the net sheet is a two-dimensional material. Therefore, this study aimed to establish calculation procedures for estimating fine root production rates from two-dimensional fine root data on net sheets. This study was conducted in a hinoki cypress (Chamaecyparis obtusa (Sieb. & Zucc.) Endl.) stand in western Japan. We estimated fine root production rates in length and volume from the number (RN) and cross-sectional area (RCSA) densities, respectively, for fine roots crossing the net sheets, which were then converted to dry mass values. For these calculations, we used empirical regression equations or theoretical equations between the RN or RCSA densities on the vertical walls of soil pits and fine root densities in length or volume, respectively, in the soil, wherein the theoretical equations assumed random orientation of the growing fine roots. The estimates of mean fine root (diameter <1 mm) production rates were ∼80-100 g m-2 year-1 using the empirically obtained regression equations, whereas those from the theoretical equations were ∼40-50 g m-2 year-1. The difference in the estimates was attributed to larger slope values of the empirical regression equations than those of the theoretical equations, suggesting that fine root orientation was not random in our study site. In light of these results, we concluded that fine root production rates were successfully estimated from two-dimensional fine root data on the net sheets using these calculation procedures, with the empirical regression equations reflecting fine root orientation in the study site. © The Author 2017. Published by

  4. Does species richness affect fine root biomass and production in young forest plantations?

    PubMed

    Domisch, Timo; Finér, Leena; Dawud, Seid Muhie; Vesterdal, Lars; Raulund-Rasmussen, Karsten

    2015-02-01

    Tree species diversity has been reported to increase forest ecosystem above-ground biomass and productivity, but little is known about below-ground biomass and production in diverse mixed forests compared to single-species forests. For testing whether species richness increases below-ground biomass and production and thus complementarity between forest tree species in young stands, we determined fine root biomass and production of trees and ground vegetation in two experimental plantations representing gradients in tree species richness. Additionally, we measured tree fine root length and determined species composition from fine root biomass samples with the near-infrared reflectance spectroscopy method. We did not observe higher biomass or production in mixed stands compared to monocultures. Neither did we observe any differences in tree root length or fine root turnover. One reason for this could be that these stands were still young, and canopy closure had not always taken place, i.e. a situation where above- or below-ground competition did not yet exist. Another reason could be that the rooting traits of the tree species did not differ sufficiently to support niche differentiation. Our results suggested that functional group identity (i.e. conifers vs. broadleaved species) can be more important for below-ground biomass and production than the species richness itself, as conifers seemed to be more competitive in colonising the soil volume, compared to broadleaved species.

  5. CHARACTERIZING THE SOURCES OF HUMAN EXPOSURE TO MUTAGENIC AND CARCINOGENIC CHEMICALS IN AIRBORNE FINE PARTICLES

    EPA Science Inventory

    Personal and ambient exposures to airborne fine particles, polycyclic aromatic hydrocarbons (PAH), and genotoxic activity has been studied in populations in the US, Japan, China, and the Czech Republic. Personal exposure monitors used to collect fine particles were extracted f...

  6. CHARACTERIZING THE SOURCES OF HUMAN EXPOSURE TO MUTAGENIC AND CARCINOGENIC CHEMICALS IN AIRBORNE FINE PARTICLES

    EPA Science Inventory

    Personal and ambient exposures to airborne fine particles, polycyclic aromatic hydrocarbons (PAH), and genotoxic activity has been studied in populations in the US, Japan, China, and the Czech Republic. Personal exposure monitors used to collect fine particles were extracted f...

  7. Engineering cyanobacteria for fuels and chemicals production.

    PubMed

    Zhou, Jie; Li, Yin

    2010-03-01

    The world's energy and global warming crises call for sustainable, renewable, carbon-neutral alternatives to replace fossil fuel resources. Currently, most biofuels are produced from agricultural crops and residues, which lead to concerns about food security and land shortage. Compared to the current biofuel production system, cyanobacteria, as autotrophic prokaryotes, do not require arable land and can grow to high densities by efficiently using solar energy, CO(2), water, and inorganic nutrients. Moreover, powerful genetic techniques of cyanobacteria have been developed. For these reasons, cyanobacteria, which carry out oxygenic photosynthesis, are attractive hosts for production of fuels and chemicals. Recently, several chemicals including ethanol, isobutanol and isoprene have been produced by engineered cyanobacteria directly using solar energy, CO(2), and water. Cyanobacterium is therefore a potential novel cell factory for fuels and chemicals production to address global energy security and climate change issues.

  8. Fragranced consumer products: Chemicals emitted, ingredients unlisted

    SciTech Connect

    Steinemann, Anne C.; MacGregor, Ian C.; Gordon, Sydney M.; Gallagher, Lisa G.; Davis, Amy L.; Ribeiro, Daniel S.; Wallace, Lance A.

    2011-04-15

    Fragranced consumer products are pervasive in society. Relatively little is known about the composition of these products, due to lack of prior study, complexity of formulations, and limitations and protections on ingredient disclosure in the U.S. We investigated volatile organic compounds (VOCs) emitted from 25 common fragranced consumer products-laundry products, personal care products, cleaning supplies, and air fresheners-using headspace analysis with gas chromatography/mass spectrometry (GC/MS). Our analysis found 133 different VOCs emitted from the 25 products, with an average of 17 VOCs per product. Of these 133 VOCs, 24 are classified as toxic or hazardous under U.S. federal laws, and each product emitted at least one of these compounds. For 'green' products, emissions of these compounds were not significantly different from the other products. Of all VOCs identified across the products, only 1 was listed on any product label, and only 2 were listed on any material safety data sheet (MSDS). While virtually none of the chemicals identified were listed, this nonetheless accords with U.S. regulations, which do not require disclosure of all ingredients in a consumer product, or of any ingredients in a mixture called 'fragrance.' Because the analysis focused on compounds emitted and listed, rather than exposures and effects, it makes no claims regarding possible risks from product use. Results of this study contribute to understanding emissions from common products, and their links with labeling and legislation.

  9. Chemical characterization and source apportionment of fine and coarse particulate matter in Lahore, Pakistan

    NASA Astrophysics Data System (ADS)

    Stone, Elizabeth; Schauer, James; Quraishi, Tauseef A.; Mahmood, Abid

    2010-03-01

    Lahore, Pakistan is an emerging megacity that is heavily polluted with high levels of particle air pollution. In this study, respirable particulate matter (PM 2.5 and PM 10) were collected every sixth day in Lahore from 12 January 2007 to 19 January 2008. Ambient aerosol was characterized using well-established chemical methods for mass, organic carbon (OC), elemental carbon (EC), ionic species (sulfate, nitrate, chloride, ammonium, sodium, calcium, and potassium), and organic species. The annual average concentration (±one standard deviation) of PM 2.5 was 194 ± 94 μg m -3 and PM 10 was 336 ± 135 μg m -3. Coarse aerosol (PM 10-2.5) was dominated by crustal sources like dust (74 ± 16%, annual average ± one standard deviation), whereas fine particles were dominated by carbonaceous aerosol (organic matter and elemental carbon, 61 ± 17%). Organic tracer species were used to identify sources of PM 2.5 OC and chemical mass balance (CMB) modeling was used to estimate relative source contributions. On an annual basis, non-catalyzed motor vehicles accounted for more than half of primary OC (53 ± 19%). Lesser sources included biomass burning (10 ± 5%) and the combined source of diesel engines and residual fuel oil combustion (6 ± 2%). Secondary organic aerosol (SOA) was an important contributor to ambient OC, particularly during the winter when secondary processing of aerosol species during fog episodes was expected. Coal combustion alone contributed a small percentage of organic aerosol (1.9 ± 0.3%), but showed strong linear correlation with unidentified sources of OC that contributed more significantly (27 ± 16%). Brick kilns, where coal and other low quality fuels are burned together, are suggested as the most probable origins of unapportioned OC. The chemical profiling of emissions from brick kilns and other sources unique to Lahore would contribute to a better understanding of OC sources in this megacity.

  10. Fine particulate matter source apportionment using a hybrid chemical transport and receptor model approach

    NASA Astrophysics Data System (ADS)

    Hu, Y.; Balachandran, S.; Pachon, J. E.; Baek, J.; Ivey, C.; Holmes, H.; Odman, M. T.; Mulholland, J. A.; Russell, A. G.

    2013-10-01

    A hybrid fine particulate matter (PM2.5) source apportionment approach based on a receptor-model (RM) species balance and species specific source impacts from a chemical transport model (CTM) equipped with a sensitivity analysis tool is developed to provide physically- and chemically-consistent relationships between source emissions and receptor impacts. This hybrid approach enhances RM results by providing initial estimates of source impacts from a much larger number of sources than are typically used in RMs, and provides source-receptor relationships for secondary species. Further, the method addresses issues of source collinearities, and accounts for emissions uncertainties. Hybrid method results also provide information on the resulting source impact uncertainties. We apply this hybrid approach to conduct PM2.5 source apportionment at Chemical Speciation Network (CSN) sites across the US. Ambient PM2.5 concentrations at these receptor sites were apportioned to 33 separate sources. Hybrid method results led to large changes of impacts from CTM estimates for sources such as dust, woodstove, and other biomass burning sources, but limited changes to others. The refinements reduced the differences between CTM-simulated and observed concentrations of individual PM2.5 species by over 98% when using a weighted least squared error minimization. The rankings of source impacts changed from the initial estimates, revealing that CTM-only results should be evaluated with observations. Assessment with RM results at six US locations showed that the hybrid results differ somewhat from commonly resolved sources. The hybrid method also resolved sources that typical RM methods do not capture without extra measurement information on unique tracers. The method can be readily applied to large domains and long (such as multi-annual) time periods to provide source impact estimates for management- and health-related studies.

  11. Fine particulate matter source apportionment using a hybrid chemical transport and receptor model approach

    NASA Astrophysics Data System (ADS)

    Hu, Y.; Balachandran, S.; Pachon, J. E.; Baek, J.; Ivey, C.; Holmes, H.; Odman, M. T.; Mulholland, J. A.; Russell, A. G.

    2014-06-01

    A hybrid fine particulate matter (PM2.5) source apportionment approach based on a receptor model (RM) species balance and species specific source impacts from a chemical transport model (CTM) equipped with a sensitivity analysis tool is developed to provide physically and chemically consistent relationships between source emissions and receptor impacts. This hybrid approach enhances RM results by providing initial estimates of source impacts from a much larger number of sources than are typically used in RMs, and provides source-receptor relationships for secondary species. Further, the method addresses issues of source collinearities and accounts for emissions uncertainties. We apply this hybrid approach to conduct PM2.5 source apportionment at Chemical Speciation Network (CSN) sites across the US. Ambient PM2.5 concentrations at these receptor sites were apportioned to 33 separate sources. Hybrid method results led to large changes of impacts from CTM estimates for sources such as dust, woodstoves, and other biomass-burning sources, but limited changes to others. The refinements reduced the differences between CTM-simulated and observed concentrations of individual PM2.5 species by over 98% when using a weighted least-squares error minimization. The rankings of source impacts changed from the initial estimates, further demonstrating that CTM-only results should be evaluated with observations. Assessment with RM results at six US locations showed that the hybrid results differ somewhat from commonly resolved sources. The hybrid method also resolved sources that typical RM methods do not capture without extra measurement information for unique tracers. The method can be readily applied to large domains and long (such as multi-annual) time periods to provide source impact estimates for management- and health-related studies.

  12. On the longevity of desert plants and the production of new fine roots

    NASA Astrophysics Data System (ADS)

    Vargas, R.; Czimczik, C. I.; Bullock, S.; Xu, X.; Djuricin, S.

    2012-12-01

    There is evidence that some plants in arid regions can live for several hundreds of years suggesting a strong resilience to climate variability including drought events. Therefore, an important question is: Which are the physiological mechanisms of survival that are present in long-lived plants? Recent studies have shown that plants are able to store nonstructural carbon (NSC) for several years and then allocate them for production of new structures such as fine roots. We established an experiment to measure the radiocarbon age of new fine roots of desert plants between 150 and 400 years old. The study site was located at the Central Desert of Baja California, Mexico and included individuals of Brahea armata, Washingtonia robusta, and Pachycereus pringlei. Our results showed that on average all the plant species were able to use stored old carbon for production of new fine roots. These results suggest that NSC pools are important in determining belowground responses of long-lived desert plants.

  13. Fine root dynamics and forest production across a calcium gradient in northern hardwood and conifer ecosystems

    USGS Publications Warehouse

    Park, B.B.; Yanai, R.D.; Fahey, T.J.; Bailey, S.W.; Siccama, T.G.; Shanley, J.B.; Cleavitt, N.L.

    2008-01-01

    Losses of soil base cations due to acid rain have been implicated in declines of red spruce and sugar maple in the northeastern USA. We studied fine root and aboveground biomass and production in five northern hardwood and three conifer stands differing in soil Ca status at Sleepers River, VT; Hubbard Brook, NH; and Cone Pond, NH. Neither aboveground biomass and production nor belowground biomass were related to soil Ca or Ca:Al ratios across this gradient. Hardwood stands had 37% higher aboveground biomass (P = 0.03) and 44% higher leaf litter production (P < 0.01) than the conifer stands, on average. Fine root biomass (<2 mm in diameter) in the upper 35 cm of the soil, including the forest floor, was very similar in hardwoods and conifers (5.92 and 5.93 Mg ha-1). The turnover coefficient (TC) of fine roots smaller than 1 mm ranged from 0.62 to 1.86 y-1 and increased significantly with soil exchangeable Ca (P = 0.03). As a result, calculated fine root production was clearly higher in sites with higher soil Ca (P = 0.02). Fine root production (biomass times turnover) ranged from 1.2 to 3.7 Mg ha-1 y-1 for hardwood stands and from 0.9 to 2.3 Mg ha-1 y -1 for conifer stands. The relationship we observed between soil Ca availability and root production suggests that cation depletion might lead to reduced carbon allocation to roots in these ecosystems. ?? 2008 Springer Science+Business Media, LLC.

  14. Novel Chemical Space Exploration via Natural Products

    PubMed Central

    Rosén, Josefin; Gottfries, Johan; Muresan, Sorel; Backlund, Anders; Oprea, Tudor I.

    2009-01-01

    Natural products (NPs) are a rich source of novel compound classes and new drugs. In the present study we have used the chemical space navigation tool ChemGPS-NP to evaluate the chemical space occupancy by NPs and bioactive medicinal chemistry compounds from the database WOMBAT. The two sets differ notable in coverage of chemical space, and tangible lead-like NPs were found to cover regions of chemical space that lack representation in WOMBAT. Property based similarity calculations were performed to identify NP neighbours of approved drugs. Several of the NPs revealed by this method, were confirmed to exhibit the same activity as their drug neighbours. The identification of leads from a NP starting point may prove a useful strategy for drug discovery, in the search for novel leads with unique properties. PMID:19265440

  15. Novel chemical space exploration via natural products.

    PubMed

    Rosén, Josefin; Gottfries, Johan; Muresan, Sorel; Backlund, Anders; Oprea, Tudor I

    2009-04-09

    Natural products (NPs) are a rich source of novel compound classes and new drugs. In the present study we have used the chemical space navigation tool ChemGPS-NP to evaluate the chemical space occupancy by NPs and bioactive medicinal chemistry compounds from the database WOMBAT. The two sets differ notably in coverage of chemical space, and tangible leadlike NPs were found to cover regions of chemical space that lack representation in WOMBAT. Property based similarity calculations were performed to identify NP neighbors of approved drugs. Several of the NPs revealed by this method were confirmed to exhibit the same activity as their drug neighbors. The identification of leads from a NP starting point may prove a useful strategy for drug discovery in the search for novel leads with unique properties.

  16. Dissociative Experiences, Creative Imagination, and Artistic Production in Students of Fine Arts

    ERIC Educational Resources Information Center

    Perez-Fabello, Maria Jose; Campos, Alfredo

    2011-01-01

    The current research was designed to assess the influence of dissociative experiences and creative imagination on the artistic production of Fine Arts students of the University of Vigo (Spain). The sample consisted of 81 students who were administered the Creative Imagination Scale and The Dissociative Experiences Scale. To measure artistic…

  17. Fine Root Dynamics and Forest Production Across a Calcium Gradient in Northern Hardwood and Conifer Ecosystems

    Treesearch

    Byung Bae Park; Ruth D. Yanai; Timothy J. Fahey; Scott W. Bailey; Thomas G. Siccama; James B. Shanley; Natalie L. Cleavitt

    2008-01-01

    Losses of soil base cations due to acid rain have been implicated in declines of red spruce and sugar maple in the northeastern USA. We studied fine root and aboveground biomass and production in five northern hardwood and three conifer stands differing in soil Ca status at Sleepers River, VT; Hubbard Brook, NH; and Cone Pond, NH. Neither aboveground biomass and...

  18. ESTIMATES OF DOUGLAS-FIR FINE ROOT PRODUCTION AND MORTALITY FROM MINIRHIZOTRONS

    EPA Science Inventory

    Minirhizotrons were used to assess the influence of soil resources on fine root (diameter < 2 mm) production, mortality, and standing crop over a two-year period. Two study sites were located, along an elevational transect, in the Oregon Cascade Mountains in mature (> 100 years o...

  19. EFFECT OF SOIL N ON FINE ROOT PRODUCTION AND MORTALITY IN PSEUDOTSUGA MENZIESII

    EPA Science Inventory

    The influence of soil N level on fine (diameter < 2 mm) root standing crop, production and mortality was assessed over a three-year period using minirhizotron tubes. Study sites were located in the central Oregon Cascade mountains in mature stands (> 100 years old) of Pseudotsuga...

  20. ESTIMATES OF DOUGLAS-FIR FINE ROOT PRODUCTION AND MORTALITY FROM MINIRHIZOTRONS

    EPA Science Inventory

    Minirhizotrons were used to assess the influence of soil resources on fine root (diameter < 2 mm) production, mortality, and standing crop over a two-year period. Two study sites were located, along an elevational transect, in the Oregon Cascade Mountains in mature (> 100 years o...

  1. EFFECT OF SOIL N ON FINE ROOT PRODUCTION AND MORTALITY IN PSEUDOTSUGA MENZIESII

    EPA Science Inventory

    The influence of soil N level on fine (diameter < 2 mm) root standing crop, production and mortality was assessed over a three-year period using minirhizotron tubes. Study sites were located in the central Oregon Cascade mountains in mature stands (> 100 years old) of Pseudotsuga...

  2. Fine-tuning of process conditions to improve product uniformity of polystyrene particles used for wind tunnel velocimetry

    NASA Technical Reports Server (NTRS)

    Ray, Asit K.

    1990-01-01

    Monodisperse polymer particles (having uniform diameter) were used for the last two decades in physical, biological, and chemical sciences. In NASA Langley Research Center monodisperse polystyrene particles are used in wind tunnel laser velocimeters. These polystyrene (PS) particles in latex form were formulated at the Engineering Laboratory of FENGD using emulsion-free emulsion polymerization. Monodisperse PS latices particles having different particle diameters were formulated and useful experimental data involving effects of process conditions on particle size were accumulated. However, similar process conditions and chemical recipes for polymerization of styrene monomer have often yielded monodisperse particles having varying diameters. The purpose was to improve the PS latex product uniformity by fine-tuning the process parameters based on the knowledge of suspension and emulsion polymerization.

  3. The chemical composition of fine ambient aerosol particles in the Beijing area

    NASA Astrophysics Data System (ADS)

    Nekat, Bettina; van Pinxteren, Dominik; Iinuma, Yoshiteru; Gnauk, Thomas; Müller, Konrad; Herrmann, Hartmut

    2010-05-01

    The strong economical growth in China during the last few decades led to heavy air pollution caused by significantly increased particle emissions. The aerosol particles affect not only the regional air quality and visibility, but can also influence cloud formation processes and the radiative balance of the atmosphere by their optical and microphysical properties. The ability to act as Cloud Condensation Nuclei (CCN) is related to microphysical properties like the hygroscopic growth or the cloud droplet activation. The chemical composition of CCN plays an important role on these properties and varies strongly with the particle size and the time of day. Hygroscopic or surface active substances can increase the hygroscopicity and lower the surface tension of the particle liquid phase, respectively. The presence of such compounds may result in faster cloud droplet activation by faster water uptake. The DFG project HaChi (Haze in China) aimed at studying physical and chemical parameters of urban aerosol particles in the Beijing area in order to associate the chemical composition of aerosol particles with their ability to act as CCN. To this end, two measurement campaigns were performed at the Wuqing National Ordinary Meteorological Observing Station, which is a background site near Beijing. The winter campaign was realized in March 2009 and the summer campaign took place from mid July 2009 to mid August 2009. Fine particles with an aerodynamic diameter smaller than or equal 1 μm were continuously sampled for 24h over the two campaigns using a DIGITEL high volume sampler (DHA-80). The present contribution presents and discusses the results of the chemical characterization of the DIGITEL filters samples. The filters were analyzed for the mass concentration, inorganic ions and carbon sum parameters like elemental (EC), organic (OC) and water soluble organic carbon (WSOC). The WSOC fraction was further characterized for hygroscopic substances like low molecular

  4. Estimation of fine-root production using rates of diameter-dependent root mortality, decomposition and thickening in forests.

    PubMed

    Van Do, Tran; Osawa, Akira; Sato, Tamotsu

    2016-04-01

    Current studies indicate that fine roots of different diameter classes show different rates of decomposition. This study developed a new method to estimate fine-root production by considering the difference in the production of fine roots of two size classes, fine roots thinner than 1 mm and those between 1 and 2 mm, and their corresponding rates of decomposition. A litter bag experiment was used to estimate the decomposition rates, while the sequential soil core technique was used to identify mass values of live roots and dead roots at a given period of observation. The continuous inflow method was applied to estimate the amount of root decomposition, mortality and production with a framework of two diameter classes of fine roots and for quantification of the amount of mass transfer from the thicker fine-root class to the coarser root category (>2 mm). The results indicated that the estimate of fine-root production was greater when two size classes of fine roots were distinguished. Using a framework of two size classes developed in this study resulted in 21.3% higher fine-root production than a method that did not recognize fine-root size classes or mass transfer to the category of coarse roots. In addition, using shorter collection intervals led to higher production estimates than longer intervals. The production estimate with a 1-month interval was 21.4% higher than that with a 6-month interval. We consider that the use of the sequential soil core technique with continuous inflow estimate method by differentiating size classes of fine roots is likely to minimize the underestimation of the parameters of fine-root dynamics by accounting for decomposition and mortality of fine roots more appropriately.

  5. The Mulled Coal process: An advanced fine coal preparation technology used to improve the handling characteristics of fine wet coal products

    SciTech Connect

    Jamison, P.R.

    1996-12-31

    The Mulled Coal process is a simple low cost method of improving the handling characteristics of the fine wet coal. The process involves the addition of a specifically formulated reagent to fine wet coal by mixing the two together in a pug mill. The converted material (Mulled Coal) retains some of its original surface moisture, but it handles, stores and transports like dry coal. It does not cause any of the sticking, fouling, bridging and freezing problems normally associated with fine wet coal, and, unlike thermally dried fine coal, it will not rewet and it is not dusty. In the process, large (baseball size) loosely bound sticky masses of fine wet coal particles are broken down into granules which are fairly uniform in the 28 Mesh x 0 size range. Due to the unique combination of the mixing action of the pug mill, the surface chemistry of the fine coal particles and the properties of the reagent; the individual granules are tightly bound, and they become completely enveloped by a very thin film of reagent. The reagent envelope will allow moisture out in the vapor stage, but it will not allow moisture back into the agglomerated granule. The envelope also prevents individual granules from adhering to or freezing to one another. The end result is a fine coal product which is free flowing, which is not dusty, and which will not rewet.

  6. Can Wet Rocky Granular Flows Become Debris Flows Due to Fine Sediment Production by Abrasion?

    NASA Astrophysics Data System (ADS)

    Arabnia, O.; Sklar, L. S.; Bianchi, G.; Mclaughlin, M. K.

    2015-12-01

    Debris flows are rapid mass movements in which elevated pore pressures are sustained by a viscous fluid matrix with high concentrations of fine sediments. Debris flows may form from coarse-grained wet granular flows as fine sediments are entrained from hillslope and channel material. Here we investigate whether abrasion of the rocks within a granular flow can produce sufficient fine sediments to create debris flows. To test this hypothesis experimentally, we used a set of 4 rotating drums ranging from 0.2 to 4.0 m diameter. Each drum has vanes along the boundary ensure shearing within the flow. Shear rate was varied by changing drum rotational velocity to maintain a constant Froude Number across drums. Initial runs used angular clasts of granodiorite with a tensile strength of 7.6 MPa, with well-sorted coarse particle size distributions linearly scaled with drum radius. The fluid was initially clear water, which rapidly acquired fine-grained wear products. After each 250 m tangential distance, we measured the particle size distributions, and then returned all water and sediment to the drums for subsequent runs. We calculate particle wear rates using statistics of size and mass distributions, and by fitting the Sternberg equation to the rate of mass loss from the size fraction > 2mm. Abundant fine sediments were produced in the experiments, but very little change in the median grain size was detected. This appears to be due to clast rounding, as evidenced by a decrease in the number of stable equilibrium resting points. We find that the growth in the fine sediment concentration in the fluid scales with unit drum power. This relationship can be used to estimate fine sediment production rates in the field. We explore this approach at Inyo Creek, a steep catchment in the Sierra Nevada, California. There, a significant debris flow occurred in July 2013, which originated as a coarse-grained wet granular flow. We use surveys to estimate flow depth and velocity where super

  7. Friction and Wear of Ion-Beam-Deposited Diamondlike Carbon on Chemical-Vapor-Deposited, Fine-Grain Diamond

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa; Wu, Richard L. C.; Lanter, William C.

    1996-01-01

    Friction and wear behavior of ion-beam-deposited diamondlike carbon (DLC) films coated on chemical-vapor-deposited (CVD), fine-grain diamond coatings were examined in ultrahigh vacuum, dry nitrogen, and humid air environments. The DLC films were produced by the direct impact of an ion beam (composed of a 3:17 mixture of Ar and CH4) at ion energies of 1500 and 700 eV and an RF power of 99 W. Sliding friction experiments were conducted with hemispherical CVD diamond pins sliding on four different carbon-base coating systems: DLC films on CVD diamond; DLC films on silicon; as-deposited, fine-grain CVD diamond; and carbon-ion-implanted, fine-grain CVD diamond on silicon. Results indicate that in ultrahigh vacuum the ion-beam-deposited DLC films on fine-grain CVD diamond (similar to the ion-implanted CVD diamond) greatly decrease both the friction and wear of fine-grain CVD diamond films and provide solid lubrication. In dry nitrogen and in humid air, ion-beam-deposited DLC films on fine-grain CVD diamond films also had a low steady-state coefficient of friction and a low wear rate. These tribological performance benefits, coupled with a wider range of coating thicknesses, led to longer endurance life and improved wear resistance for the DLC deposited on fine-grain CVD diamond in comparison to the ion-implanted diamond films. Thus, DLC deposited on fine-grain CVD diamond films can be an effective wear-resistant, lubricating coating regardless of environment.

  8. [Dangerous drugs: products containing synthetic chemicals].

    PubMed

    Kamijo, Yoshito

    2016-02-01

    When the patients poisoned with "dangerous drugs", that is, products containing synthetic chemicals such as synthetic cannabinoids and cathinones, are transferred to the emergency facilities, the chemicals really consumed cannot be determined there. So, supportive care may be the most important strategy for treating them. For example, those with serious consciousness disturbance should be supported with ventilator after intubation. Those with remarkable excitatory CNS or sympathetic symptoms, benzodiazepines such as diazepam and midazolam, should be administered. Those with hallucination or delusion, antipsychotics such as haloperidol or risperidone should be administered. Those with rhabdomyolysis, hypermyoglobinemia and acute kidney injury, intravenous fluids and hemodialysis should be introduced.

  9. Chemical characterization of fine organic aerosol for source apportionment at Monterrey, Mexico

    NASA Astrophysics Data System (ADS)

    Mancilla, Y.; Mendoza, A.; Fraser, M. P.; Herckes, P.

    2015-07-01

    , source attribution results obtained using the CMB model indicate that emissions from motor vehicle exhausts are the most important, accounting for the 64 % of the PM2.5. The vegetative detritus and biomass burning had the smallest contribution (2.2 % of the PM2.5). To our knowledge, this is the second study to explore the broad chemical characterization of fine organic aerosol in Mexico and the first for the MMA.

  10. Enhancing of chemical compound and drug name recognition using representative tag scheme and fine-grained tokenization

    PubMed Central

    2015-01-01

    Background The functions of chemical compounds and drugs that affect biological processes and their particular effect on the onset and treatment of diseases have attracted increasing interest with the advancement of research in the life sciences. To extract knowledge from the extensive literatures on such compounds and drugs, the organizers of BioCreative IV administered the CHEMical Compound and Drug Named Entity Recognition (CHEMDNER) task to establish a standard dataset for evaluating state-of-the-art chemical entity recognition methods. Methods This study introduces the approach of our CHEMDNER system. Instead of emphasizing the development of novel feature sets for machine learning, this study investigates the effect of various tag schemes on the recognition of the names of chemicals and drugs by using conditional random fields. Experiments were conducted using combinations of different tokenization strategies and tag schemes to investigate the effects of tag set selection and tokenization method on the CHEMDNER task. Results This study presents the performance of CHEMDNER of three more representative tag schemes-IOBE, IOBES, and IOB12E-when applied to a widely utilized IOB tag set and combined with the coarse-/fine-grained tokenization methods. The experimental results thus reveal that the fine-grained tokenization strategy performance best in terms of precision, recall and F-scores when the IOBES tag set was utilized. The IOBES model with fine-grained tokenization yielded the best-F-scores in the six chemical entity categories other than the "Multiple" entity category. Nonetheless, no significant improvement was observed when a more representative tag schemes was used with the coarse or fine-grained tokenization rules. The best F-scores that were achieved using the developed system on the test dataset of the CHEMDNER task were 0.833 and 0.815 for the chemical documents indexing and the chemical entity mention recognition tasks, respectively. Conclusions The

  11. Characterization of chemical components and bioreactivity of fine particulate matter (PM2.5) during incense burning.

    PubMed

    Lui, K H; Bandowe, Benjamin A Musa; Ho, Steven Sai Hang; Chuang, Hsiao-Chi; Cao, Jun-Ji; Chuang, Kai-Jen; Lee, S C; Hu, Di; Ho, K F

    2016-06-01

    The chemical and bioreactivity properties of fine particulate matter (PM2.5) emitted during controlled burning of different brands of incense were characterized. Incenses marketed as being environmentally friendly emitted lower mass of PM2.5 particulates than did traditional incenses. However, the environmentally friendly incenses produced higher total concentrations of non-volatile polycyclic aromatic hydrocarbons (PAHs) and some oxygenated polycyclic aromatic hydrocarbons (OPAHs). Human alveolar epithelial A549 cells were exposed to the collected PM2.5, followed by determining oxidative stress and inflammation. There was moderate to strong positive correlation (R > 0.60, p < 0.05) between selected PAHs and OPAHs against oxidative-inflammatory responses. Strong positive correlation was observed between interleukin 6 (IL-6) and summation of total Group B2 PAHs/OPAHs (∑7PAHs/ΣOPAHs). The experimental data indicate that emissions from the environmentally friendly incenses contained higher concentrations of several PAH and OPAH compounds than did traditional incense. Moreover, these PAHs and OPAHs were strongly correlated with inflammatory responses. The findings suggest a need to revise existing regulation of such products.

  12. Anionic Extraction for Efficient Recovery of Biobased 2,3-Butanediol-A Platform for Bulk and Fine Chemicals.

    PubMed

    Drabo, Peter; Tiso, Till; Heyman, Benedikt; Sarikaya, Eda; Gaspar, Paula; Förster, Jochen; Büchs, Jochen; Blank, Lars Mathias; Delidovich, Irina

    2017-08-24

    2,3-Butanediol (BDO) presents a promising platform molecule for the synthesis of basic and fine chemicals. Biotechnological production of BDO from renewable resources with living microbes enables high concentrations in the fermentation broth. The recovery of high-boiling BDO from an aqueous fermentation broth presents a subsequent challenge. A method is proposed for BDO isolation based on reversible complexation with phenylboronate in an anionic complex. BDO can be recovered by back-extraction into an acidic solution. The composition of the extracted species was determined by NMR spectroscopy, MS, and GC-MS methods. The conditions of extraction and back-extraction were optimized by using commercial BDO and finally applied to different fermentation broths. Up to 72-93 % BDO can be extracted and up to 80-90 % can be back-extracted under the optimized conditions. Purified bio-BDO was used in the presence of sulfuric acid for the synthesis of methyl ethyl ketone, an established organic solvent and discussed tailor-made biofuel. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Chemical production of chondrule oxygen isotopic composition

    NASA Technical Reports Server (NTRS)

    Thiemens, M. H.

    1994-01-01

    Defining the source of observed meteoritic O isotopic anomalies remains a fundamental challenge. The O isotopic composition of chondrules are particularly striking. There are at least three types of chemical processes that produce the isotopic compositions observed in chondrules and Ca-Al-rich inclusions (CAI's). The processes are rather general, viz, they require no specialized processes and the processes associated with chondrule production are likely to produce the observed compositions.

  14. Chemical characterization of commercial liquid smoke products

    PubMed Central

    Montazeri, Naim; Oliveira, Alexandra CM; Himelbloom, Brian H; Leigh, Mary Beth; Crapo, Charles A

    2013-01-01

    The objective of this study was to determine important chemical characteristics of a full-strength liquid smoke, Code 10-Poly, and three refined liquid smoke products (AM-3, AM-10 and 1291) commercially available (Kerry Ingredients and Flavors, Monterey, TN). The pH of the products were significantly different (P < 0.05) and ranged from 2.3 (Code 10-Poly) to 5.7 (1291). The pH was inversely correlated with titratable acidity (R2 = 0.87), which was significantly different (P < 0.05) among products ranging from 10.3% acetic acid (Code 10-Poly) to 0.7% acetic acid (1291). Total phenol content was quantified using the Gibbs reaction; the only liquid smoke containing appreciable level of phenolic compounds was Code 10-Poly at 3.22 mg mL−1. Gas chromatography-mass spectrometry (GC-MS) analysis of liquid smoke dichloromethane extracts revealed that carbonyl-containing compounds were major constituents of all products, in which 1-hydroxy-2-butanone, 2(5H)-furanone, propanal and cyclopentenone predominated. Organic acids were detected by GC-MS in all extracts and correlated positively (R2 = 0.98) with titratable acidity. The GC-MS data showed that phenolic compounds constituted a major portion of Code 10-Poly, and were detected only in trace quantities in 1291. The refined liquid smokes had lighter color, lower acidity, and reduced level of carbonyl-containing compounds and organic acids. Our study revealed major differences in pH, titratable acidity, total phenol content, color and chemical make-up of the full-strength and refined liquid smokes. The three refined liquid smoke products studied have less flavor and color active compounds, when compared with the full-strength product. Furthermore, the three refined products studied have unique chemical characteristics and will impart specific sensorial properties to food systems. Understanding the chemical composition of liquid smokes, be these refined or full-strength products, is an important step to

  15. Fine particulate matter and visibility in the Lake Tahoe Basin: chemical characterization, trends, and source apportionment.

    PubMed

    Green, Mark C; Chen, L W Antony; DuBois, David W; Molenar, John V

    2012-08-01

    Speciated PM2.5 (particulate matter with an aerodynamic diameterFine mass at SOLA is 2.5 times that at BLIS, mainly due to enhanced organic and elemental carbon (OC and EC). SOLA experiences a winter peak in PM25 mainly due to OC and EC from residential wood combustion, whereas BLIS experiences a summer peak in PM2.5 mainly due to OC and ECfrom wildfires. Carbonaceous aerosol dominates visibility impairment, causing about 1/2 the reconstructed aerosol light extinction at BLIS and 70% at SOLA. Trend analysis (1990-2009) showed statistically significant decreases in aerosol extinction at BLIS on 20% best and 60% middle visibility days and statistically insignificant upward trends on 20% worst days. SOLA (1990-2003) showed statistically significant decreases in aerosol extinction for all day categories, driven by decreasing OC and EC. From the regional haze rule baseline period of 2000-2004 until 2005-2009, BLIS saw 20% best days improving and 20% worst days getting worse due to increased wildfire effects. Receptor modeling was performed using positive matrix factorization (PMF) and chemical mass balance (CMB). It confirmed that (1) biomass burning dominanted PM25 sources at both sites with increasing importance over time; (2) low combustion efficiency burning accounts for most of the biomass burning contribution; (3) road dust and traffic contributions were much higher at SOLA than at BLIS; and (4) industrial combustion and salting were minor sources.

  16. Effects of chemical dispersants and mineral fines on crude oil dispersion in a wave tank under breaking waves.

    PubMed

    Li, Zhengkai; Kepkay, Paul; Lee, Kenneth; King, Thomas; Boufadel, Michel C; Venosa, Albert D

    2007-07-01

    The interaction of chemical dispersants and suspended sediments with crude oil influences the fate and transport of oil spills in coastal waters. A wave tank study was conducted to investigate the effects of chemical dispersants and mineral fines on the dispersion of oil and the formation of oil-mineral-aggregates (OMAs) in natural seawater. Results of ultraviolet spectrofluorometry and gas chromatography flame ionized detection analysis indicated that dispersants and mineral fines, alone and in combination, enhanced the dispersion of oil into the water column. Measurements taken with a laser in situ scattering and transmissometer (LISST-100X) showed that the presence of mineral fines increased the total concentration of the suspended particles from 4 to 10microl l(-1), whereas the presence of dispersants decreased the particle size (mass mean diameter) of OMAs from 50 to 10microm. Observation with an epifluorescence microscope indicated that the presence of dispersants, mineral fines, or both in combination significantly increased the number of particles dispersed into the water.

  17. Chemical safety of meat and meat products.

    PubMed

    Andrée, Sabine; Jira, W; Schwind, K-H; Wagner, H; Schwägele, F

    2010-09-01

    Since the Second World War the consumer behaviour in developed countries changed drastically. Primarily there existed the demand for sufficient food after a period of starvation, afterwards the desire for higher quality was arising, whereas today most people ask for safe and healthy food with high quality. Therefore a united approach comprising consistent standards, sound science and robust controls is required to ensure consumers' health and to maintain consumers' confidence and satisfaction. Chemical analysis along the whole food chain downstream (tracking) from primary production to the consumer and upstream (tracing) from the consumer to primary production is an important prerequisite to ensure food safety and quality. In this frame the focus of the following paper is the "chemical safety of meat and meat products" taking into account inorganic as well as organic residues and contaminants, the use of nitrite in meat products, the incidence of veterinary drugs, as well as a Failure Mode and Effect Analysis (FMEA) system assessing (prioritizing) vulnerable food chain steps to decrease or eliminate vulnerability.

  18. 76 FR 4549 - Testing of Certain High Production Volume Chemicals; Second Group of Chemicals; Technical Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-26

    ... AGENCY 40 CFR Part 799 RIN 2070-AD16 Testing of Certain High Production Volume Chemicals; Second Group of... testing of certain high production volume (HPV) chemical substances to obtain screening level data for.... 799.5087 Chemical testing requirements for second group of high production volume chemicals...

  19. Considering distortion product otoacoustic emission fine structure in measurements of the medial olivocochlear reflex

    PubMed Central

    Abdala, Carolina; Mishra, Srikanta K.; Williams, Tracy L.

    2009-01-01

    In humans, when the medial olivocochlear (MOC) pathway is activated by noise in the opposite ear, changes in distortion product otoacoustic emission (DPOAE) level, i.e., the MOC reflex, can be recorded in the test ear. Recent evidence suggests that DPOAE frequency influences the direction (suppression∕enhancement) of the reflex. In this study, DPOAEs were recorded at fine frequency intervals from 500 to 2500 Hz, with and without contralateral acoustic stimulation (CAS) in a group of 15 adults. The MOC reflex was calculated only at DPOAE frequencies corresponding to peaks in the fine structure. Additionally, inverse fast-Fourier transform was conducted to evaluate MOC effects on individual DPOAE components. Results show the following: (1) When considering peaks only, the mean MOC reflex was −2.05 dB and 97% of observations reflected suppression, (2) CAS reduced distortion characteristic frequency component levels more than overlap component levels, and (3) CAS produced an upward shift in fine structure peak frequency. Results indicate that when the MOC reflex is recorded at DPOAE frequencies corresponding to fine structure maxima (i.e., when DPOAE components are constructive and in phase), suppression is reliably observed and level enhancement, which probably reflects component mixing in the ear canal rather than strength of the MOC reflex, is eliminated. PMID:19275316

  20. Permeability Enhancement in Fine-Grained Sediments by Chemically Induced Clay Fabric Shrinkage

    SciTech Connect

    Wijesinghe, A M; Kansa, E J; Viani, B E; Blake, R G; Roberts, J J; Huber, R D

    2004-02-26

    The National Research Council [1] identified the entrapment of contaminants in fine-grained clay-bearing soils as a major impediment to the timely and cost-effective remediation of groundwater to regulatory standards. Contaminants trapped in low-permeability, low-diffusivity, high-sorptivity clays are not accessible to advective flushing by treatment fluids from permeable zones, and slowly diffuse out to recontaminate previously cleaned permeable strata. We propose to overcome this barrier to effective remediation by exploiting the ability of certain nontoxic EPA-approved chemicals (e.g., ethanol) to shrink and alter the fabric of clays, and thereby create macro-porosity and crack networks in fine-grained sediments. This would significantly reduce the distance and time scales of diffusive mass transport to advectively flushed boundaries, to yield orders of magnitude reduction in the time required to complete remediation. Given that effective solutions to this central problem of subsurface remediation do not yet exist, the cost and time benefits of successful deployment of this novel concept, both as a stand-alone technology and as an enabling pre-treatment for other remedial technologies that rely on advective delivery, is likely to be very large. This project, funded as a 1-year feasibility study by LLNL's LDRD Program, is a multi-directorate, multi-disciplinary effort that leverages expertise from the Energy & Environment Directorate, the Environmental Restoration Division, and the Manufacturing & Materials Evaluation Division of Mechanical Engineering. In this feasibility study, a ''proof-of-principle'' experiment was performed to answer the central question: ''Can clay shrinkage induced by ethanol in clay-bearing sediments overcome realistic confining stresses, crack clay, and increase its effective permeability by orders of magnitude within a time that is much smaller than the time required for diffusive mass transport of ethanol in the unaltered sediment

  1. Unit Price Scaling Trends for Chemical Products

    SciTech Connect

    Qi, Wei; Sathre, Roger; William R. Morrow, III; Shehabi, Arman

    2015-08-01

    To facilitate early-stage life-cycle techno-economic modeling of emerging technologies, here we identify scaling relations between unit price and sales quantity for a variety of chemical products of three categories - metal salts, organic compounds, and solvents. We collect price quotations for lab-scale and bulk purchases of chemicals from both U.S. and Chinese suppliers. We apply a log-log linear regression model to estimate the price discount effect. Using the median discount factor of each category, one can infer bulk prices of products for which only lab-scale prices are available. We conduct out-of-sample tests showing that most of the price proxies deviate from their actual reference prices by a factor less than ten. We also apply the bootstrap method to determine if a sample median discount factor should be accepted for price approximation. We find that appropriate discount factors for metal salts and for solvents are both -0.56, while that for organic compounds is -0.67 and is less representative due to greater extent of product heterogeneity within this category.

  2. Speciated fine particulate matter in Northern Italy: A whole year chemical and transport modelling reconstruction

    NASA Astrophysics Data System (ADS)

    Lonati, G.; Pirovano, G.; Sghirlanzoni, G. A.; Zanoni, A.

    2010-03-01

    The so-called "one atmosphere modelling approach" is applied over a mesoscale domain and model outputs for gaseous pollutants (NO X and O 3) and for size resolved PM mass concentration (PM10 and PM2.5) are compared to observed data time series at reference sites representative of different locations (urban, suburban and rural sites) throughout the modelling domain. The CAMx model (Comprehensive Air quality Model with eXtensions) was used for simulation over the Po valley air basin with a 10 × 10 km 2 spatial resolution based on emission and meteorological data for the 01/04/2003-31/03/2004 period. Model results for speciated PM2.5 mass concentration (including nitrate, sulphate, ammonium, elemental carbon and organic matter) are compared to artefact-corrected data from campaigns performed for the city of Milan and its neighbourhoods. Since model results are not concurrent with the available PM2.5 measurements, bootstrapping technique is applied in order to extract from model results restricted warm-season and cold-season data populations suitable for quantitative comparison with measured data. The model seems able to correctly reproduce the spatial distribution and the local concentration gradients of both PM10 and PM2.5 bulk mass with high concentration levels on the Po valley, increasing around urban areas. However, the comparison with experimental data shows relevant underestimations of PM10 and PM2.5 concentrations, especially at the most polluted urban "hot spots", where underestimations rise up to 60% of the actual PM levels. Speciated PM2.5 results, still in agreement with local composition gradients, point out that PM mass underestimations essentially derive from a 60% underestimation of organic matter (in both seasons) and sulphate (cold season only) concentrations, whereas a rather good agreement is observed for the other chemical species and especially for the ammonium-nitrate system. Such results suggest to better refine emission inventory data, with

  3. Characterizing chemical transport of ozone and fine particles in the Great Lakes region

    NASA Astrophysics Data System (ADS)

    Spak, Scott N.

    This dissertation presents a science framework relevant to evaluating impacts of land use policy scenarios, energy technologies, and climate on urban and regional air quality. Emerging from collaboration with urban planners, this work provides a means for employing atmospheric chemical transport modeling to understand environmental ramifications of long-term, spatially disaggregated changes in population and automobile emissions at the census tract level, and to assess the sensitivity of these changes to densification strategies. Toward these goals, the framework is used to evaluate model skill in resolving contemporary characteristics of ozone (O3) and speciated fine particles (PM2.5) in the Great Lakes region of North America, and to quantitatively explore meteorological processes that bring about observed features of these pollutants in the region. The Great Lakes were chosen due to a population concentrated in sprawling metropolitan areas, consistently high and widespread pollutant burdens, and seasonal effects of the lakes on the atmosphere. In annual simulation at 36 km resolution, the Community Multiscale Air Quality model is evaluated using speciated PM2.5 measurements taken at regulatory monitoring networks orientated to sample urban, rural, and remote areas. Performance relative to ad-hoc regional modeling goals and prior studies is average to excellent for most species throughout the year. Both pollution episodes and seasonality are captured. The Great Lakes affect pollution seasonality: strong winds advect aerosols around the deep marine boundary layer to lower surface PM2.5 in fall and winter, while O3 over the lakes is enhanced throughout the year, driven by temperature in the cool seasons and lake breeze circulation in spring and summer. Simulations confirm observational evidence that rural and small-city sources are responsible for most regional PM2.5. Sensitivities to urban and rural reductions are of comparable magnitude on a percentage basis

  4. Chemical analysis of World Trade Center fine particulate matter for use in toxicologic assessment.

    PubMed

    McGee, John K; Chen, Lung Chi; Cohen, Mitchell D; Chee, Glen R; Prophete, Colette M; Haykal-Coates, Najwa; Wasson, Shirley J; Conner, Teri L; Costa, Daniel L; Gavett, Stephen H

    2003-06-01

    The catastrophic destruction of the World Trade Center (WTC) on 11 September 2001 caused the release of high levels of airborne pollutants into the local environment. To assess the toxicity of fine particulate matter [particulate matter with a mass median aerodynamic diameter < 2.5 microm (PM2.5)], which may adversely affect the health of workers and residents in the area, we collected fallen dust samples on 12 and 13 September 2001 from sites within a half-mile of Ground Zero. Samples of WTC dust were sieved, aerosolized, and size-separated, and the PM2.5 fraction was isolated on filters. Here we report the chemical and physical properties of PM2.5 derived from these samples and compare them with PM2.5 fractions of three reference materials that range in toxicity from relatively inert to acutely toxic (Mt. St. Helens PM; Washington, DC, ambient air PM; and residual oil fly ash). X-ray diffraction of very coarse sieved WTC PM (< 53 microm) identified calcium sulfate (gypsum) and calcium carbonate (calcite) as major components. Scanning electron microscopy confirmed that calcium-sulfur and calcium-carbon particles were also present in the WTC PM2.5 fraction. Analysis of WTC PM2.5 using X-ray fluorescence, neutron activation analysis, and inductively coupled plasma spectrometry showed high levels of calcium (range, 22-33%) and sulfur (37-43% as sulfate) and much lower levels of transition metals and other elements. Aqueous extracts of WTC PM2.5 were basic (pH range, 8.9-10.0) and had no evidence of significant bacterial contamination. Levels of carbon were relatively low, suggesting that combustion-derived particles did not form a significant fraction of these samples recovered in the immediate aftermath of the destruction of the towers. Because gypsum and calcite are known to cause irritation of the mucus membranes of the eyes and respiratory tract, inhalation of high doses of WTC PM2.5 could potentially cause toxic respiratory effects.

  5. Chemical analysis of World Trade Center fine particulate matter for use in toxicologic assessment.

    PubMed Central

    McGee, John K; Chen, Lung Chi; Cohen, Mitchell D; Chee, Glen R; Prophete, Colette M; Haykal-Coates, Najwa; Wasson, Shirley J; Conner, Teri L; Costa, Daniel L; Gavett, Stephen H

    2003-01-01

    The catastrophic destruction of the World Trade Center (WTC) on 11 September 2001 caused the release of high levels of airborne pollutants into the local environment. To assess the toxicity of fine particulate matter [particulate matter with a mass median aerodynamic diameter < 2.5 microm (PM2.5)], which may adversely affect the health of workers and residents in the area, we collected fallen dust samples on 12 and 13 September 2001 from sites within a half-mile of Ground Zero. Samples of WTC dust were sieved, aerosolized, and size-separated, and the PM2.5 fraction was isolated on filters. Here we report the chemical and physical properties of PM2.5 derived from these samples and compare them with PM2.5 fractions of three reference materials that range in toxicity from relatively inert to acutely toxic (Mt. St. Helens PM; Washington, DC, ambient air PM; and residual oil fly ash). X-ray diffraction of very coarse sieved WTC PM (< 53 microm) identified calcium sulfate (gypsum) and calcium carbonate (calcite) as major components. Scanning electron microscopy confirmed that calcium-sulfur and calcium-carbon particles were also present in the WTC PM2.5 fraction. Analysis of WTC PM2.5 using X-ray fluorescence, neutron activation analysis, and inductively coupled plasma spectrometry showed high levels of calcium (range, 22-33%) and sulfur (37-43% as sulfate) and much lower levels of transition metals and other elements. Aqueous extracts of WTC PM2.5 were basic (pH range, 8.9-10.0) and had no evidence of significant bacterial contamination. Levels of carbon were relatively low, suggesting that combustion-derived particles did not form a significant fraction of these samples recovered in the immediate aftermath of the destruction of the towers. Because gypsum and calcite are known to cause irritation of the mucus membranes of the eyes and respiratory tract, inhalation of high doses of WTC PM2.5 could potentially cause toxic respiratory effects. PMID:12782501

  6. Production of fine calcium powders by centrifugal atomization with rotating quench bath

    DOE PAGES

    Tian, Liang; Anderson, Iver; Riedemann, Trevor; ...

    2016-02-08

    Recently, a novel Al/Ca composite was produced by severe plastic deformation of Al powders and Ca granules for possible use as a high-voltage power transmission conductor. Since the strength of such composites is inversely proportional to the Ca filament size, fine Ca powders (less than ~250 μm) are needed to achieve the desired high strength for the powder metallurgy production of an Al-matrix composite reinforced by nano-scale Ca filaments. However, fine Ca powders are not commercially available. Therefore, we have developed a method to produce fine Ca powders via centrifugal atomization to supply Ca powder for prototype development of Al/Camore » composite conductor. A secondary goal of the project was to demonstrate that Ca powder can be safely prepared, stored, and handled and could potentially be scaled for commercial production. Our results showed that centrifugal atomization can yield as much as 83 vol. % Ca powder particles smaller than 250 μm. The mean particle size sometimes matches, sometimes deviates substantially from the predictions of the Champagne & Anger equation likely due to unexpected secondary atomization. The particle size distribution is typical for a ligament-disintegration atomization mode. Scanning electron micrographs showed that the morphology of these Ca powders varied with powder size. Spark testing and auto-ignition tests indicated that the atomized powders were difficult to ignite, providing confidence that this material can be handled safely in air.« less

  7. Production of fine calcium powders by centrifugal atomization with rotating quench bath

    SciTech Connect

    Tian, Liang; Anderson, Iver; Riedemann, Trevor; Russell, Alan

    2016-02-08

    Recently, a novel Al/Ca composite was produced by severe plastic deformation of Al powders and Ca granules for possible use as a high-voltage power transmission conductor. Since the strength of such composites is inversely proportional to the Ca filament size, fine Ca powders (less than ~250 μm) are needed to achieve the desired high strength for the powder metallurgy production of an Al-matrix composite reinforced by nano-scale Ca filaments. However, fine Ca powders are not commercially available. Therefore, we have developed a method to produce fine Ca powders via centrifugal atomization to supply Ca powder for prototype development of Al/Ca composite conductor. A secondary goal of the project was to demonstrate that Ca powder can be safely prepared, stored, and handled and could potentially be scaled for commercial production. Our results showed that centrifugal atomization can yield as much as 83 vol. % Ca powder particles smaller than 250 μm. The mean particle size sometimes matches, sometimes deviates substantially from the predictions of the Champagne & Anger equation likely due to unexpected secondary atomization. The particle size distribution is typical for a ligament-disintegration atomization mode. Scanning electron micrographs showed that the morphology of these Ca powders varied with powder size. Spark testing and auto-ignition tests indicated that the atomized powders were difficult to ignite, providing confidence that this material can be handled safely in air.

  8. Production of Chemical Derivatives from Renewables

    SciTech Connect

    Davison, Brian; Nghiem, John; Donnelly, Mark; Tsai, Shih-Perng; Frye, John; Landucci, Ron; Griffin, Michael

    1996-06-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corp., (LMER), Argonne National Laboratory (ANL), National Renewable Energy Laboratory (NREL), and Battelle Memorial Institute, operator of Pacific Northwest National Laboratory (PNNL), (collectively referred to as the 'Contractor'), and Applied Carbochemicals, Inc. (Participant) was to scale-up from bench results an economically promising and competitive process for the production of chemical derivatives from biologically produced succinic acid. The products that were under consideration for production from the succinic acid platform included 1,4-butanediol, {gamma}y-butyrolactone, 2-pyrrolidinone and N-methyl pyrrolidinone. Preliminary economic analyses indicated that this platform was competitive with the most recent petrochemical routes. The Contractors and participant are hereinafter jointly referred to as the 'Parties.' Research to date in succinic acid fermentation, separation and genetic engineering resulted in a potentially economical process based on the use of an Escherichia coli strain AFP111 with suitable characteristics for the production of succinic acid from glucose. Economic analysis has shown that higher value commodity chemicals can be economically produced from succinic acid based on preliminary laboratory findings and predicted catalytic parameters. At the time, the current need was to provide the necessary laboratory follow-up information to properly optimize, design and operate a pilot scale process. The purpose of the pilot work was to validate the integrated process, assure 'robustness' of the process, define operating conditions, and provide samples for potential customer evaluation. The data from the pilot scale process was used in design and development of a full scale production facility. A new strain, AFP111 (patented), discovered at ANL was tested and developed for process use at the Oak Ridge National Laboratory (ORNL

  9. Chemical composition of emissions from urban sources of fine organic aerosol

    SciTech Connect

    Hildemann, L.M.; Markowski, G.R.; Cass, G.R. )

    1991-04-01

    A dilution source sampling system was used to collect primary fine aerosol emissions from important sources of urban organic aerosol, including a boiler burning No. 2 fuel oil, a home fireplace, a fleet of catalyst-equipped and noncatalyst automobiles, heavy-duty diesel trucks, natural gas home appliances, and meat cooking operations. Alternative dilution sampling techniques were used to collect emissions from cigarette smoking and a roofing tar pot, and grab sample techniques were employed to characterize paved road dust, brake lining wear, and vegetative detritus. Organic aerosol constituted the majority of the fine aerosol mass emitted from many of the sources tested. Fine primary organic aerosol emissions within the heavily urbanized western portion of the Los Angeles Basin were determined to total 29.8 metric ton/day. Over 40% of these organic aerosol emissions are from anthropogenic pollution sources that are expected to emit contemporary (nonfossil) aerosol carbon, in good agreement with the available ambient monitoring data.

  10. Assessment of cloud-related fine-mode AOD enhancements based on AERONET SDA product

    NASA Astrophysics Data System (ADS)

    Arola, Antti; Eck, Thomas F.; Kokkola, Harri; Pitkänen, Mikko R. A.; Romakkaniemi, Sami

    2017-05-01

    AERONET (AErosol RObotic NETwork), which is a network of ground-based sun photometers, produces a data product called the aerosol spectral deconvolution algorithm (SDA) that utilizes spectral total aerosol optical depth (AOD) data to infer the component fine- and coarse-mode optical depths at 500 nm. Based on its assumptions, SDA identifies cloud optical depth as the coarse-mode AOD component and therefore effectively computes the fine-mode AOD also in mixed cloud-aerosol observations. Therefore, it can be argued that the more representative AOD for fine-mode fraction should be based on all direct sun measurements and not only on those cloud screened for clear-sky conditions, i.e., on those from level 1 (L1) instead of level 2 (L2) in AERONET. The objective of our study was to assess, including all the available AERONET sites, how the fine-mode AOD is enhanced in cloudy conditions, contrasting SDA L1 and L2 in our analysis. Assuming that the cloud screening correctly separates the cloudy and clear-sky conditions, then the increases in fine-mode AOD can be due to various cloud-related processes, mainly by the strong hygroscopic growth of particles in the vicinity of clouds and in-cloud processing leading to growth of accumulation mode particles. We estimated these cloud-related enhancements in fine-mode AOD seasonally and found, for instance, that in June-August season the average over all the AERONET sites was 0.011, when total fine-mode AOD from L2 data was 0.154; therefore, the relative enhancement was 7 %. The enhancements were largest, both absolutely and relatively, in East Asia; for example, in June-August season the absolute and relative differences in fine-mode AOD, between L1 and L2 measurements, were 0.022 and 10 %, respectively. Corresponding values in North America and Europe were about 0.01 and 6-7 %. In some highly polluted areas, the enhancement is greater than these regional averages, e.g., in Beijing region and in June-July-August (JJA) season the

  11. Chemical mass transport between fluid fine tailings and the overlying water cover of an oil sands end pit lake

    NASA Astrophysics Data System (ADS)

    Dompierre, Kathryn A.; Barbour, S. Lee; North, Rebecca L.; Carey, Sean K.; Lindsay, Matthew B. J.

    2017-06-01

    Fluid fine tailings (FFT) are a principal by-product of the bitumen extraction process at oil sands mines. Base Mine Lake (BML)—the first full-scale demonstration oil sands end pit lake (EPL)—contains approximately 1.9 × 108 m3 of FFT stored under a water cover within a decommissioned mine pit. Chemical mass transfer from the FFT to the water cover can occur via two key processes: (1) advection-dispersion driven by tailings settlement; and (2) FFT disturbance due to fluid movement in the water cover. Dissolved chloride (Cl) was used to evaluate the water cover mass balance and to track mass transport within the underlying FFT based on field sampling and numerical modeling. Results indicated that FFT was the dominant Cl source to the water cover and that the FFT is exhibiting a transient advection-dispersion mass transport regime with intermittent disturbance near the FFT-water interface. The advective pore water flux was estimated by the mass balance to be 0.002 m3 m-2 d-1, which represents 0.73 m of FFT settlement per year. However, the FFT pore water Cl concentrations and corresponding mass transport simulations indicated that advection rates and disturbance depths vary between sample locations. The disturbance depth was estimated to vary with location between 0.75 and 0.95 m. This investigation provides valuable insight for assessing the geochemical evolution of the water cover and performance of EPLs as an oil sands reclamation strategy.

  12. Fine root dynamics in lodgepole pine and white spruce stands along productivity gradients in reclaimed oil sands sites.

    PubMed

    Jamro, Ghulam Murtaza; Chang, Scott X; Naeth, M Anne; Duan, Min; House, Jason

    2015-10-01

    Open-pit mining activities in the oil sands region of Alberta, Canada, create disturbed lands that, by law, must be reclaimed to a land capability equivalent to that existed before the disturbance. Re-establishment of forest cover will be affected by the production and turnover rate of fine roots. However, the relationship between fine root dynamics and tree growth has not been studied in reclaimed oil sands sites. Fine root properties (root length density, mean surface area, total root biomass, and rates of root production, turnover, and decomposition) were assessed from May to October 2011 and 2012 using sequential coring and ingrowth core methods in lodgepole pine (Pinus contorta Dougl.) and white spruce (Picea glauca (Moench.) Voss) stands. The pine and spruce stands were planted on peat mineral soil mix placed over tailings sand and overburden substrates, respectively, in reclaimed oil sands sites in Alberta. We selected stands that form a productivity gradient (low, medium, and high productivities) of each tree species based on differences in tree height and diameter at breast height (DBH) increments. In lodgepole pine stands, fine root length density and fine root production, and turnover rates were in the order of high > medium > low productivity sites and were positively correlated with tree height and DBH and negatively correlated with soil salinity (P < 0.05). In white spruce stands, fine root surface area was the only parameter that increased along the productivity gradient and was negatively correlated with soil compaction. In conclusion, fine root dynamics along the stand productivity gradients were closely linked to stand productivity and were affected by limiting soil properties related to the specific substrate used for reconstructing the reclaimed soil. Understanding the impact of soil properties on fine root dynamics and overall stand productivity will help improve land reclamation outcomes.

  13. Chemical mass balance source apportionment of fine and PM10 in the Desert Southwest, USA

    EPA Science Inventory

    The Desert Southwest Coarse Particulate Matter Study was undertaken in Pinal County, Arizona, to better understand the origin and impact of sources of fine and coarse particulate matter (PM) in rural, arid regions of the U.S. southwestern desert. The desert southwest experiences ...

  14. Chemical mass balance source apportionment of fine and PM10 in the Desert Southwest, USA

    EPA Science Inventory

    The Desert Southwest Coarse Particulate Matter Study was undertaken in Pinal County, Arizona, to better understand the origin and impact of sources of fine and coarse particulate matter (PM) in rural, arid regions of the U.S. southwestern desert. The desert southwest experiences ...

  15. Using the Photolysis of Chemically Modified Gel Films Preparing ITO Fine Patterned Thin Films

    NASA Astrophysics Data System (ADS)

    Li, Ying; Zhao, Gaoyang; Zhang, Weihua; Chen, Yuanqing

    2006-06-01

    A novel technique for the fabrication of tin-doped indium oxide (ITO) fine patterning in sol-gel technology is presented in this paper. The fabricated ITO fine patterning could be obtained through a process which combines film fabrication with film etching. ITO films have good comprehensive property of visible transmittance and electrical conductivity, consequently they have been extensively used as coating electrodes. Indium nitrate (In(NO3)3.4.5H2O) and stannic chloride (SnCl4.5H2O) were used as starting materials which were modified with benzytone (BzAcH). The chelate complexes containing indium ions were produced during the process which of forming photosensitive ITO/BzAcH gel films through sol-gel technique. It was found that the gel films are sensitive to both the ultraviolet (UV) light irradiation and their solubility on solvents as well. For example, ethanol was reduced remarkably while the UV absorption peak disappeared with the dissociation of the chelate complexes correspondingly by means of UV-vis and IR spectrophotometers. Utilizing these characteristics, a fine pattern was obtained by irradiation of UV light on the ITO/BzAcH gel films through a pattern mask. of the fine patterned ITO films were heat treated at 500 °C for 15 min, the optical, electrical properties and the surface element components were examined by X-ray photoelectron spectroscopy (XPS) spectra in this work.

  16. [Fine root production in initial stage of Castanopsis carlesii under different regeneration modes in Sanming, Fujian Province, China].

    PubMed

    Hu, Shuang-chen; Xiong, De-cheng; Huang, Jin-xue; Deng, Fei; Chen, Yun-yu; Liu, Xiao-fei; Chen, Guang-shui

    2015-11-01

    Fine root biomass and production in initial stage of three different regeneration approaches, i.e., natural regeneration with anthropogenic promotion (AR) , the Castanopsis carlesii plantation ( CC) and the Cunninghamia lanceolata plantation ( CL) on the clear-cutting sites of the secondary forest of C. carlesii (CK), in Sanming, Fujian Province, were investigated by using both minrhizotrons and the soil coring methods. The results of a year observation showed that the average fine root biomass was 422.5, 253.1, 197.2 and 162.8 g · m(-2), and the fine root production was 284.0, 182.6, 136.7 and 15.4 g · m(-2) · a(-1) for AR, CC, CL and CK, respectively. The maximum value of production was found in spring for AR and CC, in autumn for CL, and in winter for CK. Fine root production of other plants was higher than that of target tree species in CC, and vice verse in CL. There was a significant positive correlation between monthly fine root production and monthly precipitation in AR and CC. Significant positive correlation was found between monthly fine root production of other plants and monthly temperature in CL. The fine root under annual production and annual average biomass of these three young forests mainly distributed in the soil layer of 20- 40 cm, and mainly in the diameter class of 0-1 mm. The study demonstrated that the biomass and production of fine root under anthropogenic promotion were greater than that of the plantation, and the method of anthropogenic promotion were more conducive to increase the returning of organic matter, improve soil fertility, and maintain a high productivity in initial stage of forest regeneration.

  17. Quantification of geopolymers production by chemical methods- A short review

    NASA Astrophysics Data System (ADS)

    Siyal, Ahmer Ali; Azizli, Khairun Azizi; Ismail, Lukman; Man, Zakaria; Khan, Muhammad Irfan

    2015-07-01

    Inorganic polymers are the aluminosilicate materials possessing properties superior than ordinary Portland cement. In this review paper the chemical techniques used for determining degree of reaction of fly ash or the quantity of geopolymer material produced have been discussed. These methods determine the amount of product formed in percentages. The methods include HCl method, salicylic acid method, and picric acid method. These methods are not only used for fly ash but they are being used for determining the degree of reactions of metakaolin and other pozzolanic materials. The picric acid is an explosive material and its transportation in high concentration is dangerous. During its use in laboratory there is also the risk of fire associated with it. According to the microscopic analysis results the picric acid attack dissolves small amount of fine unreacted fly ash particles also. The salicylic acid is easily available but the residue from its treatment contains unreacted fly ash particles, hydration phases, and certain parts of unreacted OPC. The residue from HCl and salicylic acid attack contains MgO particles which is the part of the hydration product. The HCl method is mostly used due to simple process and lower standard deviation.

  18. Changes in fine-root production, phenology and spatial distribution in response to N application in irrigated sweet cherry trees.

    PubMed

    Artacho, Pamela; Bonomelli, Claudia

    2016-05-01

    Factors regulating fine-root growth are poorly understood, particularly in fruit tree species. In this context, the effects of N addition on the temporal and spatial distribution of fine-root growth and on the fine-root turnover were assessed in irrigated sweet cherry trees. The influence of other exogenous and endogenous factors was also examined. The rhizotron technique was used to measure the length-based fine-root growth in trees fertilized at two N rates (0 and 60 kg ha(-1)), and the above-ground growth, leaf net assimilation, and air and soil variables were simultaneously monitored. N fertilization exerted a basal effect throughout the season, changing the magnitude, temporal patterns and spatial distribution of fine-root production and mortality. Specifically, N addition enhanced the total fine-root production by increasing rates and extending the production period. On average, N-fertilized trees had a length-based production that was 110-180% higher than in control trees, depending on growing season. Mortality was proportional to production, but turnover rates were inconsistently affected. Root production and mortality was homogeneously distributed in the soil profile of N-fertilized trees while control trees had 70-80% of the total fine-root production and mortality concentrated below 50 cm depth. Root mortality rates were associated with soil temperature and water content. In contrast, root production rates were primarily under endogenous control, specifically through source-sink relationships, which in turn were affected by N supply through changes in leaf photosynthetic level. Therefore, exogenous and endogenous factors interacted to control the fine-root dynamics of irrigated sweet cherry trees. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. Aluminium recovery vs. hydrogen production as resource recovery options for fine MSWI bottom ash fraction.

    PubMed

    Biganzoli, Laura; Ilyas, Aamir; Praagh, Martijn van; Persson, Kenneth M; Grosso, Mario

    2013-05-01

    Waste incineration bottom ash fine fraction contains a significant amount of aluminium, but previous works have shown that current recovery options based on standard on-step Eddy Current Separation (ECS) have limited efficiency. In this paper, we evaluated the improvement in the efficiency of ECS by using an additional step of crushing and sieving. The efficiency of metallic Al recovery was quantified by measuring hydrogen gas production. The ash samples were also tested for total aluminium content with X-ray fluorescence spectroscopy (XRF). As an alternative to material recovery, we also investigated the possibility to convert residual metallic Al into useful energy, promoting H2 gas production by reacting metallic Al with water at high pH. The results show that the total aluminium concentration in the <4 mm bottom ash fraction is on average 8% of the weight of the dry ash, with less than 15% of it being present in the metallic form. Of this latter, only 21% can be potentially recovered with ECS combined with crushing and sieving stages and subsequently recycled. For hydrogen production, using 10MNaOH at 1L/S ratio results in the release of 6-11l of H2 gas for each kilogram of fine dry ash, equivalent to an energy potential of 118 kJ.

  20. Chemical characterization of indoor and outdoor fine particulate matter in an occupied apartment in Rome, Italy.

    PubMed

    Perrino, C; Tofful, L; Canepari, S

    2016-08-01

    The daily concentration and chemical composition of PM2.5 was determined in indoor and outdoor 24-h samples simultaneously collected for a total of 5 weeks during a winter and a summer period in an apartment sited in Rome, Italy. The use of a specifically developed very quiet sampler (<35 dB) allowed the execution of the study while the family living in the apartment led its normal life. The indoor concentration of PM2.5 showed a small seasonal variation, while outdoor values were much higher during the winter study. Outdoor sources were found to contribute significantly to indoor PM concentration especially during the summer, when the apartment was naturally ventilated by opening the windows. During the winter the infiltration of outdoor PM components was lower and mostly regulated by the particle dimensions. Organics displayed In/Out ratios higher than unity during both periods; their indoor production increased significantly during the weekends, where the family stayed mostly at home. PM components were grouped into macrosources (soil, sea, secondary inorganics, traffic, organics). During the summer the main contributions to outdoor PM2.5 came from soil (30%), secondary inorganics (29%) and organics (22%). Organics dominated both indoor PM2.5 during the summer (60%) and outdoor and indoor PM2.5 during the winter (51% and 66%, respectively). © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. Chemical and biological production of cyclotides

    PubMed Central

    Li, Yilong; Bi, Tao; Camarero, Julio A.

    2016-01-01

    Cyclotides are fascinating naturally occurring micro-proteins (≈30 residues long) present in several plant families, and display various biological properties such as protease inhibitory, anti-microbial, insecticidal, cytotoxic, anti-HIV and hormone-like activities. Cyclotides share a unique head-to-tail circular knotted topology of three disulfide bridges, with one disulfide penetrating through a macrocycle formed by the two other disulfides and interconnecting peptide backbones, forming what is called a cystine knot topology. This cyclic cystine knot (CCK) framework gives the cyclotides exceptional rigidity, resistance to thermal and chemical denaturation, and enzymatic stability against degradation. Interestingly, cyclotides have been shown to be orally bioavailable, and other cyclotides have been shown to cross the cell membranes. Moreover, recent reports have also shown that engineered cyclotides can be efficiently used to target extracellular and intracellular protein-protein interactions, therefore making cyclotides ideal tools for drug development to selectively target protein-protein interactions. In this work we will review all the available methods for production of these interesting proteins using chemical or biological methods. PMID:27064329

  2. Chemical dispersion of oil with mineral fines in a low temperature environment.

    PubMed

    Wang, Weizhi; Zheng, Ying; Lee, Kenneth

    2013-07-15

    The increasing risks of potential oil spills in the arctic regions, which are characterized by low temperatures, are a big challenge. The traditional dispersant method has shown limited effectiveness in oil cleanup. This work studied the role of mineral fines in the formation of oil-mineral aggregates (OMAs) at low temperature (0-4 °C) environment. The loading amount of minerals and dispersant with different dispersant and oil types were investigated under a full factorial design. The shapes and sizes of OMAs were analyzed. Results showed that the behavior of OMA formation differs when dispersant and mineral fines are used individually or together. Both the experimental and microscopic results also showed the existence of optimal dispersant to oil ratios and mineral to oil ratios. In general, poor oil removal performance was observed for more viscous oil. Corexit 9500 performed better than Corexit 9527 with various oils, in terms of oil dispersion and OMA formation.

  3. Chemical production from industrial by-product gases: Final report

    SciTech Connect

    Lyke, S.E.; Moore, R.H.

    1981-04-01

    The potential for conservation of natural gas is studied and the technical and economic feasibility and the implementation of ventures to produce such chemicals using carbon monoxide and hydrogen from byproduct gases are determined. A survey was performed of potential chemical products and byproduct gas sources. Byproduct gases from the elemental phosphorus and the iron and steel industries were selected for detailed study. Gas sampling, preliminary design, market surveys, and economic analyses were performed for specific sources in the selected industries. The study showed that production of methanol or ammonia from byproduct gas at the sites studied in the elemental phosphorus and the iron and steel industries is technically feasible but not economically viable under current conditions. Several other applications are identified as having the potential for better economics. The survey performed identified a need for an improved method of recovering carbon monoxide from dilute gases. A modest experimental program was directed toward the development of a permselective membrane to fulfill that need. A practical membrane was not developed but further investigation along the same lines is recommended. (MCW)

  4. Seasonal cycle and temperature dependence of pinene oxidation products, dicarboxylic acids and nitrophenols in fine and coarse air particulate matter

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Müller, L.; Winterhalter, R.; Moortgat, G. K.; Hoffmann, T.; Pöschl, U.

    2010-05-01

    Filter samples of fine and coarse air particulate matter (PM) collected over a period of one year in central Europe (Mainz, Germany) were analyzed for water-soluble organic compounds (WSOCs), including the α- and β-pinene oxidation products pinic acid, pinonic acid and 3-methyl-1,2,3-butanetricarboxylic acid (3-MBTCA), as well as a variety of dicarboxylic acids and nitrophenols. Seasonal variations and other characteristic features in fine, coarse, and total PM (TSP) are discussed with regard to aerosol sources and sinks in comparison to data from other studies and regions. The ratios of adipic acid and phthalic acid to azelaic acid indicate that the investigated samples were mainly influenced by biogenic sources. A strong Arrhenius-type correlation was found between the 3-MBTCA concentration and inverse temperature (R2=0.79, n=52, Ea=126±10 kJ mol-1, temperature range 275-300 K). Model calculations suggest that the temperature dependence observed for 3-MBTCA can be explained by enhanced photochemical production due to an increase of hydroxyl radical (OH) concentration with increasing temperature, whereas the influence of gas-particle partitioning appears to play a minor role. The results indicate that the OH-initiated oxidation of pinonic acid is the rate-limiting step in the formation of 3-MBTCA, and that 3-MBTCA may be a suitable tracer for the chemical aging of biogenic secondary organic aerosol (SOA) by OH radicals. An Arrhenius-type temperature dependence was also observed for the concentration of pinic acid (R2=0.60, n=56, Ea=84±9 kJ mol-1); it can be tentatively explained by the temperature dependence of biogenic pinene emission as the rate-limiting step of pinic acid formation.

  5. Seasonal cycle and temperature dependence of pinene oxidation products, dicarboxylic acids and nitrophenols in fine and coarse air particulate matter

    NASA Astrophysics Data System (ADS)

    Zhang, Y. Y.; Müller, L.; Winterhalter, R.; Moortgat, G. K.; Hoffmann, T.; Pöschl, U.

    2010-08-01

    Filter samples of fine and coarse air particulate matter (PM) collected over a period of one year in central Europe (Mainz, Germany) were analyzed for water-soluble organic compounds (WSOCs), including the α- and β-pinene oxidation products pinic acid, pinonic acid and 3-methyl-1,2,3-butanetricarboxylic acid (3-MBTCA), as well as a variety of dicarboxylic acids and nitrophenols. Seasonal variations and other characteristic features in fine, coarse, and total PM (TSP) are discussed with regard to aerosol sources and sinks in comparison to data from other studies and regions. The ratios of adipic acid and phthalic acid to azelaic acid indicate that the investigated aerosol samples were mainly influenced by biogenic sources. A strong Arrhenius-type correlation was found between the 3-MBTCA concentration and inverse temperature (R2 = 0.79, n = 52, Ea = 126 ± 10 kJ mol-1, temperature range 275-300 K). Model calculations suggest that the temperature dependence observed for 3-MBTCA can be explained by enhanced photochemical production due to an increase of hydroxyl radical (OH) concentration with increasing temperature, whereas the influence of gas-particle partitioning appears to play a minor role. The results indicate that the OH-initiated oxidation of pinonic acid is the rate-limiting step in the formation of 3-MBTCA, and that 3-MBTCA may be a suitable tracer for the chemical aging of biogenic secondary organic aerosol (SOA) by OH radicals. An Arrhenius-type temperature dependence was also observed for the concentration of pinic acid (R2 = 0.60, n = 56, Ea = 84 ± 9 kJ mol-1); it can be tentatively explained by the temperature dependence of biogenic pinene emission as the rate-limiting step of pinic acid formation.

  6. . Cheminformatic exploration of the chemical landscape of consumer products

    EPA Science Inventory

    Although Consumer products are a primary source of chemical exposures, little information is available on the chemical ingredients of these products and the concentrations at which they are present. To address this data gap, we have created a database of chemicals in consumer pro...

  7. The U.S. Chemical Industry, the Products It Makes

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1972

    1972-01-01

    This section of the annual report on the chemical industry presents data on these areas of chemical production: growth rates, man-made fibers; the 50 largest volume chemicals, major inorganics and organics, plastics, drugs, magnesium, and paint. Includes production figures for 1961, 1969, 1970, 1971 and percent change for 1970-71 and for 1961-71.…

  8. . Cheminformatic exploration of the chemical landscape of consumer products

    EPA Science Inventory

    Although Consumer products are a primary source of chemical exposures, little information is available on the chemical ingredients of these products and the concentrations at which they are present. To address this data gap, we have created a database of chemicals in consumer pro...

  9. The U.S. Chemical Industry, the Products It Makes

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1972

    1972-01-01

    This section of the annual report on the chemical industry presents data on these areas of chemical production: growth rates, man-made fibers; the 50 largest volume chemicals, major inorganics and organics, plastics, drugs, magnesium, and paint. Includes production figures for 1961, 1969, 1970, 1971 and percent change for 1970-71 and for 1961-71.…

  10. New way for accuracy measurement of fine-pitch gears in batch production

    NASA Astrophysics Data System (ADS)

    Xie, Huakun; Fu, Ying; Feng, Gang; Ye, Yong; Huang, Wenliang

    2011-05-01

    Fine-pitch gears with module ranging from 0.05 to 0.5 are widely used in the fields of dial indicators, aeronautic gauges and instruments, timers and watches and so on; but because of their small size and weak rigidity and small aount of inertia, so far there are few methods in practice being able to meet the requirements of their reliable, precise and efficient accuracy measurements, especially in batch production. Based on the gear integrated error measuring technology and the gear single flank rolling tester, a differential type of gear single flank point rolling scan measuring technique and a prototype of the gear differential single flank rolling tester have been developed to explore a new way to solve the problem. By using a special made master gear, the tester can perform not only the measurement of the gear tangential composite deviations but also the measurement of the gear elementary deviations, including profile deviations and pitch deviations, and also integrated deviatons of fine-pitch gears in batch production with high efficiency and accuracy. The conception of "Two spindles be driven in synchronization, and one differential measurement be in closed loop" and the design structure of "spindle on spindle" adopted by the prototype are introduced in the paper. Some practical measurement results in factory and a few discussions are also presented.

  11. New way for accuracy measurement of fine-pitch gears in batch production

    NASA Astrophysics Data System (ADS)

    Xie, Huakun; Fu, Ying; Feng, Gang; Ye, Yong; Huang, Wenliang

    2010-12-01

    Fine-pitch gears with module ranging from 0.05 to 0.5 are widely used in the fields of dial indicators, aeronautic gauges and instruments, timers and watches and so on; but because of their small size and weak rigidity and small aount of inertia, so far there are few methods in practice being able to meet the requirements of their reliable, precise and efficient accuracy measurements, especially in batch production. Based on the gear integrated error measuring technology and the gear single flank rolling tester, a differential type of gear single flank point rolling scan measuring technique and a prototype of the gear differential single flank rolling tester have been developed to explore a new way to solve the problem. By using a special made master gear, the tester can perform not only the measurement of the gear tangential composite deviations but also the measurement of the gear elementary deviations, including profile deviations and pitch deviations, and also integrated deviatons of fine-pitch gears in batch production with high efficiency and accuracy. The conception of "Two spindles be driven in synchronization, and one differential measurement be in closed loop" and the design structure of "spindle on spindle" adopted by the prototype are introduced in the paper. Some practical measurement results in factory and a few discussions are also presented.

  12. Chemical diversity among fine-grained soils at Gale (Mars): a chemical transition as the rover is approaching the Bagnold Dunes?

    NASA Astrophysics Data System (ADS)

    Cousin, Agnès; Forni, Olivier; Meslin, Pierre-Yves; Schroeder, Susanne; Gasnault, Olivier; Bridges, Nathan; Ehlmann, Bethany; Maurice, Sylvestre; Wiens, Roger

    2016-04-01

    The ChemCam instrument has the capability to study the chemical composition of soils at a sub-millimeter scale, thus providing an unpreceedented spatial resolution for their study. More than 300 soils have been sampled so far with ChemCam and these targets are analyzed frequently in order to monitor any change in composition along the traverse. Detailed chemical analysis as a function of grain size is of great importance in order to better constrain soils formation. Curiosity is approaching the Bagnold Dunes, the first active dune field accessible for in-situ analyses. One of the main goals is to determine or constrain the dune material chemistry as well as its provenance. This study is focusing on recent soils analyzed when ap-proaching the dunes, for a comparison with previous soil targets, and with dunes specifically. Chemical composition of fine-grained soils as we approach the Bagnold Dunes has been compared with previous fine-grained soils analyzed along the traverse. These new soils have an average sum of oxides that is significantly higher than what has been previously analyzed. This would suggest that these soils are less hydrated and probably less altered than previous ones.An enrichment in SiO2, FeO and alkali is also observed in these new fine-grained soils, which could be related to a contamination by local rocks due to erosion. Some coarser grains could correspond to an olivine component. This analysis is on-going and will be detailed as the dedicated Bagnold Dunes campaign starts. We will also report in the hydratation level of the dunes.

  13. Fine-scale in situ measurement of riverbed nitrate production and consumption in an armored permeable riverbed.

    PubMed

    Lansdown, Katrina; Heppell, Catherine M; Dossena, Matteo; Ullah, Sami; Heathwaite, A Louise; Binley, Andrew; Zhang, Hao; Trimmer, Mark

    2014-04-15

    Alteration of the global nitrogen cycle by man has increased nitrogen loading in waterways considerably, often with harmful consequences for aquatic ecosystems. Dynamic redox conditions within riverbeds support a variety of nitrogen transformations, some of which can attenuate this burden. In reality, however, assessing the importance of processes besides perhaps denitrification is difficult, due to a sparseness of data, especially in situ, where sediment structure and hydrologic pathways are intact. Here we show in situ within a permeable riverbed, through injections of (15)N-labeled substrates, that nitrate can be either consumed through denitrification or produced through nitrification, at a previously unresolved fine (centimeter) scale. Nitrification and denitrification occupy different niches in the riverbed, with denitrification occurring across a broad chemical gradient while nitrification is restricted to more oxic sediments. The narrow niche width for nitrification is in effect a break point, with the switch from activity "on" to activity "off" regulated by interactions between subsurface chemistry and hydrology. Although maxima for denitrification and nitrification occur at opposing ends of a chemical gradient, high potentials for both nitrate production and consumption can overlap when groundwater upwelling is strong.

  14. Boron carbide: Consistency of components, lattice parameters, fine structure and chemical composition makes the complex structure reasonable

    NASA Astrophysics Data System (ADS)

    Werheit, Helmut

    2016-10-01

    The complex, highly distorted structure of boron carbide is composed of B12 and B11C icosahedra and CBC, CBB and B□B linear elements, whose concentration depends on the chemical composition each. These concentrations are shown to be consistent with lattice parameters, fine structure data and chemical composition. The respective impacts on lattice parameters are estimated and discussed. Considering the contributions of the different structural components to the energy of the overall structure makes the structure and its variation within the homogeneity range reasonable; in particular that of B4.3C representing the carbon-rich limit of the homogeneity range. Replacing in B4.3C virtually the B□B components by CBC yields the hypothetical moderately distorted B4.0C (structure formula (B11C)CBC). The reduction of lattice parameters related is compatible with recently reported uncommonly prepared single crystals, whose compositions deviate from B4.3C.

  15. Ambient fine particulate concentrations and chemical composition at two sampling sites in metropolitan Pittsburgh: a 2001 intensive summer study

    NASA Astrophysics Data System (ADS)

    Modey, William K.; Eatough, Delbert J.; Anderson, Richard R.; Martello, Donald V.; Takahama, Satoshi; Lucas, Leonard J.; Davidson, Cliff I.

    The concentration and chemical composition of ambient fine particulate material (PM 2.5) is reported for two sampling sites in the Pittsburgh, Pennsylvania metropolitan area: the Department of Energy, National Energy Technology Laboratory (NETL) PM study site south of the city center, and the Carnegie Mellon Pittsburgh Air Quality Study (PAQS) site 5 km east of central Pittsburgh established with funding by the EPA Supersites Program and by DOE-NETL. Data from these sampling sites were characterized by one to three-day episodes with PM 2.5 concentrations (constructed from the sum of the chemical components) exceeding 40.0 μg m -3. The episodes were dominated by high concentrations of ammonium sulfate. The fine particle concentrations were compared with meteorological data from surface weather maps and a Hybrid Single Particle Lagrangian Integrated Trajectory model (HYSPLIT model), with back-trajectories estimated over 24 h. High PM 2.5 concentrations were associated with transition from a high pressure to a low pressure regime in advance of an approaching frontal system indicating long-range transport of pollutants. In contrast, fine particulate organic material appeared to be dominated by nearby sources. Distinct differences were observed in the diurnal variations in concentration between the two sites. The NETL site showed clear maximum concentrations of semi-volatile organic material (SVOM) during midday, and minimum concentrations of nonvolatile organic compounds in the afternoon. In contrast, the Carnegie Mellon PAQS site showed an absence of diurnal variation in SVOM, but still with minimum concentrations of nonvolatile organic compounds in the afternoon and evening. Neither site showed significant diurnal variation in ammonium sulfate.

  16. Chemical enhancement of oil production by cyclic steam injection

    SciTech Connect

    Blair, C.M. Jr.; Scribner, R.E.

    1982-12-01

    Members of a special class of interfacially active chemicals were injected into wells in Kern County, CA, immediately before and during the huff 'n' puff steaming cycle. The chemical treatment was found to give significant increases in oil production.

  17. Production of a pellet fuel from Illinois coal fines. Technical report, March 1--May 31, 1995

    SciTech Connect

    Rapp, D.; Lytle, J.

    1995-12-31

    The primary goal of this research is to produce a pellet fuel from low-sulfur Illinois coal fines which could burn with emissions of less than 1.8 lbs SO{sub 2}/10{sup 6} Btu in stoker-fired boilers. The significance of 1.8 lbs SO{sub 2}/10{sup 6} Btu is that in the Chicago (9 counties) and St. Louis (2 counties) metropolitan areas, industrial users of coal currently must comply with this level of emissions. For this effort, we will be investigating the use of fines from two Illinois mines which currently mine relatively low-sulfur reserves and that discard their fines fraction (minus 100 mesh). The research will involve investigation of multiple unit operations including column flotation, filtration and pellet production. The end result of the effort will allow for an evaluation of the commercial viability of the approach. Previously it has been decided that corn starch would be used as binder and a roller-and-die mill would be used for pellet manufacture. A quality starch binder has been identified and tested. To potentially lower binder costs, a starch that costs about 50% of the high quality starch was tested. Results indicate that the lower cost starch will not lower binder cost because more is required to produce a comparable quality pellet. Also, a petroleum in water emulsion was evaluated as a potential binder. The compound seemed to have adhesive properties but was found to be a poor binder. Arrangements have been made to collect a waste slurry from the mine previously described.

  18. ESCA studies of the surface chemistry of lunar fines. [Electron Spectroscopic Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Housley, R. M.; Grant, R. W.

    1976-01-01

    The paper presents an ESCA analysis based on the use of a synthetic lunar-glass standard that allows determination of the surface composition of lunar samples with an accuracy that appears to be better than 10% of the amount present for all major elements except Ti. It is found that, on the average, grain surfaces in the lunar fines samples 10084 and 15301 are strongly enriched in Si, moderately enriched in Fe, moderately depleted in Al and Ca, and strongly depleted in Mg. This pattern could not be produced by the deposition of any expected meteoritic vapor. Neither could it be produced by simple inverse-mass-dependent element loss during sputtering. It is suggested that at least part of the pattern may be a simple consequence of agglutinate glass formation in the fines since there is some evidence that Si can become enriched on the surface of silicate melts. These results do not support the strong enrichments in Fe on grain surfaces reported from Auger studies.

  19. ESCA studies of the surface chemistry of lunar fines. [Electron Spectroscopic Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Housley, R. M.; Grant, R. W.

    1976-01-01

    The paper presents an ESCA analysis based on the use of a synthetic lunar-glass standard that allows determination of the surface composition of lunar samples with an accuracy that appears to be better than 10% of the amount present for all major elements except Ti. It is found that, on the average, grain surfaces in the lunar fines samples 10084 and 15301 are strongly enriched in Si, moderately enriched in Fe, moderately depleted in Al and Ca, and strongly depleted in Mg. This pattern could not be produced by the deposition of any expected meteoritic vapor. Neither could it be produced by simple inverse-mass-dependent element loss during sputtering. It is suggested that at least part of the pattern may be a simple consequence of agglutinate glass formation in the fines since there is some evidence that Si can become enriched on the surface of silicate melts. These results do not support the strong enrichments in Fe on grain surfaces reported from Auger studies.

  20. Evaluation of global fine-resolution precipitation products and their uncertainty quantification in ensemble discharge simulations

    NASA Astrophysics Data System (ADS)

    Qi, W.; Zhang, C.; Fu, G.; Sweetapple, C.; Zhou, H.

    2016-02-01

    The applicability of six fine-resolution precipitation products, including precipitation radar, infrared, microwave and gauge-based products, using different precipitation computation recipes, is evaluated using statistical and hydrological methods in northeastern China. In addition, a framework quantifying uncertainty contributions of precipitation products, hydrological models, and their interactions to uncertainties in ensemble discharges is proposed. The investigated precipitation products are Tropical Rainfall Measuring Mission (TRMM) products (TRMM3B42 and TRMM3B42RT), Global Land Data Assimilation System (GLDAS)/Noah, Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation of Water Resources (APHRODITE), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), and a Global Satellite Mapping of Precipitation (GSMAP-MVK+) product. Two hydrological models of different complexities, i.e. a water and energy budget-based distributed hydrological model and a physically based semi-distributed hydrological model, are employed to investigate the influence of hydrological models on simulated discharges. Results show APHRODITE has high accuracy at a monthly scale compared with other products, and GSMAP-MVK+ shows huge advantage and is better than TRMM3B42 in relative bias (RB), Nash-Sutcliffe coefficient of efficiency (NSE), root mean square error (RMSE), correlation coefficient (CC), false alarm ratio, and critical success index. These findings could be very useful for validation, refinement, and future development of satellite-based products (e.g. NASA Global Precipitation Measurement). Although large uncertainty exists in heavy precipitation, hydrological models contribute most of the uncertainty in extreme discharges. Interactions between precipitation products and hydrological models can have the similar magnitude of contribution to discharge uncertainty as the hydrological models. A

  1. Deposition and fine particle production during dynamic flow in a dry powder inhaler: a CFD approach.

    PubMed

    Milenkovic, J; Alexopoulos, A H; Kiparissides, C

    2014-01-30

    In this work the dynamic flow as well as the particle motion and deposition in a commercial dry powder inhaler, DPI (i.e., Turbuhaler) is described using computational fluid dynamics, CFD. The dynamic flow model presented here is an extension of a steady flow model previously described in Milenkovic et al. (2013). The model integrates CFD simulations for dynamic flow, an Eulerian-fluid/Lagrangian-particle description of particle motion as well as a particle/wall interaction model providing the sticking efficiency of particles colliding with the DPI walls. The dynamic flow is imposed by a time varying outlet pressure and the particle injections into the DPI are assumed to occur instantaneously and follow a prescribed particle size distribution, PSD. The total particle deposition and the production of fine particles in the DPI are determined for different peak inspiratory flow rates, PIFR, flow increase rates, FIR, and particle injection times. The simulation results for particle deposition are found to agree well with available experimental data for different values of PIFR and FIR. The predicted values of fine particle fraction are in agreement with available experimental results when the mean size of the injected PSD is taken to depend on the PIFR. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. 25 CFR 309.22 - What are examples of painting and other fine art forms that are Indian products?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 2 2011-04-01 2011-04-01 false What are examples of painting and other fine art forms that are Indian products? 309.22 Section 309.22 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.22 What are examples of painting and...

  3. 25 CFR 309.22 - What are examples of painting and other fine art forms that are Indian products?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 2 2014-04-01 2014-04-01 false What are examples of painting and other fine art forms that are Indian products? 309.22 Section 309.22 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.22 What are examples of painting and...

  4. 25 CFR 309.22 - What are examples of painting and other fine art forms that are Indian products?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 2 2012-04-01 2012-04-01 false What are examples of painting and other fine art forms that are Indian products? 309.22 Section 309.22 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.22 What are examples of painting and...

  5. 25 CFR 309.22 - What are examples of painting and other fine art forms that are Indian products?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 2 2013-04-01 2013-04-01 false What are examples of painting and other fine art forms that are Indian products? 309.22 Section 309.22 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF THE INTERIOR PROTECTION OF INDIAN ARTS AND CRAFTS PRODUCTS § 309.22 What are examples of painting and...

  6. Products of hydratation in fine grained mixtures MgO - SiO2

    NASA Astrophysics Data System (ADS)

    Szczerba, J.; Prorok, R.; Madej, D.; Sniezek, E.

    2013-12-01

    The aim of this study was to evaluate the influence of time of ageing on phase evolution of paste from MgO-SiO2-H2O phase system. The paste was composed of fine grained sintered magnesia and microsilica in 1:2 molar ratio and water, with water to solid ratio equal 0,5. After preparation the paste was ageing during specified time up to 180 days in temperature 20° C. Phase composition of mixture of MgO and SiO2 with water was studied by XRD, DTA-TGA. The analysis revealed that product of reaction in mixture of MgO, SiO2 and water was a probably poorly crystalline magnesium silicate.

  7. Toxicity of chemical components of fine particles inhaled by aged rats: effects of concentration.

    PubMed

    Kleinman, Michael T; Hyde, Dallas M; Bufalino, Charles; Basbaum, Carol; Bhalla, Deepak K; Mautz, William J

    2003-09-01

    This study tested the hypothesis that exposure to mixtures containing fine particles and ozone (O3) would cause pulmonary injury and decrements in functions of immunological cells in exposed rats (22-24 months old) in a dose-dependent manner. Rats were exposed to high and low concentrations of ammonium bisulfate and elemental carbon and to 0.2 ppm O3. Control groups were exposed to purified air or O3 alone. The biological end points measured included histopathological markers of lung injury, bronchoalveolar lung fluid proteins, and measures of the function of the lung's innate immunological defenses (macrophage antigen-directed phagocytosis and respiratory burst activity). Exposure to O3 alone at 0.2 ppm did not result in significant changes in any of the measured end points. Exposures to the particle mixtures plus O3 produced statistically significant changes consistent with adverse effects. The low-concentration mixture produced effects that were statistically significant compared to purified air but, with the exception of macrophage Fc receptor binding, exposure to the high-concentration mixture did not. The effects of the low- and high-concentration mixtures were not significantly different. The study supports previous work that indicated that particle + O3 mixtures were more toxic than O3 alone.

  8. Characteristics of comprehensive Chemical Industry Database CD-NET : Centered around chemical product information file

    NASA Astrophysics Data System (ADS)

    Takano, Hideo

    This paper describes Chemical Product Information File of Chemical Industry Database, CD-NET provided by Chemical Data Service Inc.. It defines "information" first, then explains file organization and presents how Chemical product Information File is located in CD-NET. Mentioning its complementary relation with JICST's JOIS-F the author defines the File as chemical product information for business purpose. All of the information items in the File emphasize that it is exactly a type of business and practical database. To distinguish general items from important items by product, all of the information is categorized into II classes by general chemical product and by area. The scope and emphasized items under each class are described in detail.

  9. Chemical composition of crystalline rock fragments from Luna 16 and Luna 20 fines

    NASA Technical Reports Server (NTRS)

    Cimbalnikova, A.; Palivcova, M.; Frana, J.; Mastalka, A.

    1977-01-01

    The chemical composition (bulk, rare earth, and trace elements) of the Luna 16 mare regolith and luna 20 highland regolith is discussed. The rock samples considered are 14 basaltic rock fragments (Luna 16) and 13 rock fragments of the ANT suite (Luna 20). On the basis of bulk composition, two types of basaltic rocks have been differentiated and defined in the Luna 16 regolith: mare basalts (fundamental crystalline rocks of Mare Fecunditatis) and high-alumina basalts. The bulk analyses of rock fragments of the ANT suite also enabled distinction of two rock types: anorthositic norites and troctolites and/or spinal-troctolites (the most abundant crystalline rocks of the highland region, the landing site of luna 20), and anorthosites. The chemical compositions of Luna 16 and Luna 20 regolith samples are compared. Differences in the chemistry of the Luna 16 mare regolith and that of mare basalts are discussed. The chemical affinity between the Luna 20 highland regolith and (a) anorthositic norites and (b) troctolites and/or spinel-troctolites has been ascertained.

  10. Microwave-Assisted Synthesis of Bio-Active Heterocycles and Fine Chemicals in Aqueous Media

    EPA Science Inventory

    Human health, especially in the aging population, mostly depends on various medicines, and researchers are combating against emerging diseases by new drug discovery. Heterocyclic compounds hold a special place among pharmaceutically active natural products as well as synthetic co...

  11. Microwave-Assisted Synthesis of Bio-Active Heterocycles and Fine Chemicals in Aqueous Media

    EPA Science Inventory

    Human health, especially in the aging population, mostly depends on various medicines, and researchers are combating against emerging diseases by new drug discovery. Heterocyclic compounds hold a special place among pharmaceutically active natural products as well as synthetic co...

  12. Synthetic Organic Chemicals: United States Production and Sales, 1976.

    ERIC Educational Resources Information Center

    Adams, Roger; And Others

    This is the sixth annual report of the U.S. Trade Commission on domestic production and sales of synthetic organic chemicals and the raw materials from which they are made. The report consists of 15 sections, each covering a specified group (based primarily on use) of organic chemicals as follows: tar and tar crudes; primary products from…

  13. Synthetic Organic Chemicals: United States Production and Sales, 1976.

    ERIC Educational Resources Information Center

    Adams, Roger; And Others

    This is the sixth annual report of the U.S. Trade Commission on domestic production and sales of synthetic organic chemicals and the raw materials from which they are made. The report consists of 15 sections, each covering a specified group (based primarily on use) of organic chemicals as follows: tar and tar crudes; primary products from…

  14. Chemical Methods for the Production of Proteins

    SciTech Connect

    Kent, Stephen B.H.

    2008-09-15

    The goal of this research program was to develop improved methods for chemical peptide and protein synthesis, and to apply these methods to the total synthesis of small proteins (<80 amino acids) & integral membrane proteins.

  15. FINE STRUCTURAL OBSERVATIONS RELATING TO THE PRODUCTION OF COLOR BY THE IRIDOPHORES OF A LIZARD, ANOLIS CAROLINENSIS

    PubMed Central

    Rohrlich, Susannah T.; Porter, Keith R.

    1972-01-01

    This paper presents the results of light and electron microscopy done on iridophores in the dorsal skin of the lizard Anolis carolinensis. New fine-structural details are revealed, and their importance is discussed. Of some interest is the complex of filaments between crystalline sheets in the cell. It is proposed that this complex is involved in the arrangement of crystals into crystalline sheets, and that the crystal arrangement and spacing are critical for the production of the cells' blue-green color. Tyndall scattering and thin-film interference are discussed as possible explanations for iridophore color production in relation to the fine-structural data obtained. PMID:5013601

  16. Effect of drought on fine roots productivity in poplar-based short rotation coppice

    NASA Astrophysics Data System (ADS)

    Mani Tripathi, Abhishek; Fischer, Milan; Berhongaray, Gonzalo; Orság, Matěj; Trnka, Miroslav

    2015-04-01

    Short rotation woody crops (SRWC) are alternative source of bioenergy, which apart from their 'carbon neutrality' have potential to store carbon (C) into soil and mitigate the increasing CO2 emission. Studies of below ground biomass of trees are divided into two types according to root diameter - analysis of fine roots (less than 2 mm) and coarse roots (more than 2 mm). Trees roots are spatially highly heterogeneous and it requires large number of samples to obtain a representative estimate of belowground biomass. For this study we used hybrid poplar clone J-105 (Populus nigra x P. maximowiczii) grown under short rotation coppice system in the region of Bohemian-Moravian Highland (49o32'N, 16o15'E and altitude 530 m a.s.l.) since April 2000. The plantation with planting density of 9,216 trees ha-1 was established on the former agricultural land and the length of the rotation cycle was set to 6-8 years. While mean annual rainfall was 609 mm with mean annual temperature 7.2oC during 1981-2013 significant increase of temperature and more frequent droughts are expected. In 2011, we established drought experiment based on throughfall exclusion system, reducing up to 70 % of throughfall precipitation. Thus 2 treatments with normal and lowered soil moisture levels were introduced. In January and February 2014, we cored 18 places including drought and control using root bipartite auger. The main goal of the study is to assess the response of fine roots productivity and fine roots vertical distribution on the reduced soil water availability. Results will be presented at the conference. Acknowledgements: This study was funded by research project IGA Mendel University 2014 "Study of below ground biomass in short rotation poplar coppice (J-105) in the Czech-Moravian Highlands", project PASED (KONTAKT II LH12037 ʺDevelopment of models for the assessment of abiotic stresses in selected energy woody plantsʺ and "Building up a multidisciplinary scientific team focused on drought

  17. Endocrine Disruptors and Asthma-Associated Chemicals in Consumer Products

    PubMed Central

    Nishioka, Marcia; Standley, Laurel J.; Perovich, Laura J.; Brody, Julia Green; Rudel, Ruthann A.

    2012-01-01

    Background: Laboratory and human studies raise concerns about endocrine disruption and asthma resulting from exposure to chemicals in consumer products. Limited labeling or testing information is available to evaluate products as exposure sources. Objectives: We analytically quantified endocrine disruptors and asthma-related chemicals in a range of cosmetics, personal care products, cleaners, sunscreens, and vinyl products. We also evaluated whether product labels provide information that can be used to select products without these chemicals. Methods: We selected 213 commercial products representing 50 product types. We tested 42 composited samples of high-market-share products, and we tested 43 alternative products identified using criteria expected to minimize target compounds. Analytes included parabens, phthalates, bisphenol A (BPA), triclosan, ethanolamines, alkylphenols, fragrances, glycol ethers, cyclosiloxanes, and ultraviolet (UV) filters. Results: We detected 55 compounds, indicating a wide range of exposures from common products. Vinyl products contained > 10% bis(2-ethylhexyl) phthalate (DEHP) and could be an important source of DEHP in homes. In other products, the highest concentrations and numbers of detects were in the fragranced products (e.g., perfume, air fresheners, and dryer sheets) and in sunscreens. Some products that did not contain the well-known endocrine-disrupting phthalates contained other less-studied phthalates (dicyclohexyl phthalate, diisononyl phthalate, and di-n-propyl phthalate; also endocrine-disrupting compounds), suggesting a substitution. Many detected chemicals were not listed on product labels. Conclusions: Common products contain complex mixtures of EDCs and asthma-related compounds. Toxicological studies of these mixtures are needed to understand their biological activity. Regarding epidemiology, our findings raise concern about potential confounding from co-occurring chemicals and misclassification due to variability in

  18. Aerosol flow reactor production of fine Y1Ba2Cu3O7 powder: Fabrication of superconducting ceramics

    NASA Astrophysics Data System (ADS)

    Kodas, T. T.; Engler, E. M.; Lee, V. Y.; Jacowitz, R.; Baum, T. H.; Roche, K.; Parkin, S. S. P.; Young, W. S.; Hughes, S.; Kleder, J.; Auser, W.

    1988-05-01

    An aerosol flow reactor operating at 900-1000 °C is used to prepare high-purity Y1Ba2Cu3O7 powders with a uniform chemical composition and a submicron to micron average particle size by thermally decomposing aerosol droplets of a solution consisting of the nitrate salts of Y, Ba, and Cu in a 1:2:3 ratio. The powders were at least 99% reacted based on thermogravimetric analysis, and the x-ray diffraction pattern is essentially that of Y1Ba2Cu3O7. Magnetic susceptibility measurements showed the powders to be superconducting with a transition at 90 K even for average reactor residence times as short as 20 s. Sintering cold-pressed pellets between 900 and 1000 °C provides dense, fine grained (average size on the order of 1 μm) superconducting ceramics with sharp 90 K transitions. The grain size and shape of a final sintered part could be varied depending on powder production, processing, and sintering conditions.

  19. 75 FR 51734 - Testing of Certain High Production Volume Chemical Substances; Third Group of Chemical Substances...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... Chemicals.'' The proposed rule, when finalized, would require manufacturers, importers, and processors of certain high production volume (HPV) chemical substances to conduct testing to obtain screening level data...., chemical manufacturing and petroleum refineries. Processors of one or more of the 29 subject...

  20. Analyses of fine paste ceramics

    SciTech Connect

    Sabloff, J A

    1980-01-01

    Four chapters are included: history of Brookhaven fine paste ceramics project, chemical and mathematical procedures employed in Mayan fine paste ceramics project, and compositional and archaeological perspectives on the Mayan fine paste ceramics. (DLC)

  1. Sources and Chemical Composition of Atmospheric Fine Particles in Rabigh, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Nayebare, S. R.; Aburizaiza, O. S.; Siddique, A.; Hussain, M. M.; Zeb, J.; Khwaja, H. A.

    2014-12-01

    Air pollution research in Saudi Arabia and the whole of Middle East is at its inception, making air pollution in the region a significant problem. This study presents the first detailed data on fine particulate matter (PM2.5) concentrations of Black Carbon (BC), ions, and trace metals at Rabigh, Saudi Arabia, and assesses their sources. Results showed several characteristic aspects of air pollution at Rabigh. Daily levels of PM2.5 and BC showed significant temporal variability ranging from 12.2 - 75.9 µg/m3 and 0.39 - 1.31 µg/m3, respectively. More than 90% of the time, the daily PM2.5 exceeded the 24 h WHO guideline of 20 µg/m3. Sulfate, NO3-, and NH4+ dominated the identifiable components. Trace metals with significantly higher concentrations included Si, S, Ca, Al, Fe, Na, Cl, Mg, K, and Ti, with average concentrations of 3.1, 2.2, 1.6, 1.2, 1.1, 0.7, 0.7, 0.5, 0.4 and 0.1 µg/m3, respectively. Based on the Air Quality Index (AQI), there were 44% days of moderate air quality, 33% days of unhealthy air quality for sensitive groups, and 23% days of unhealthy air quality throughout the study period. Two categories of aerosol trace metal sources were defined: anthropogenic (S, V, Cr, Ni, Cu, Zn, Br, Cd, Sb, and Pb) and naturally derived elements (Si, Al, and Fe). The extent of anthropogenic contribution was estimated by the degree of enrichment of these elements compared to the crustal composition. Soil resuspension and/or mobilization is an important source of "natural" elements, while "anthropogenic" elements originate primarily from fossil fuel combustion and industries. Ni and V correlated strongly pointing to combustion of heavy fuel oil as the likely source. A positive matrix factorization (PMF) was used to obtain information about possible sources. Our study highlights the need for stringent laws on PM2.5 emission control to protect human health and the environment.

  2. Advanced bioreactors for enhanced production of chemicals

    SciTech Connect

    Davison, B.H.; Scott, C.D.

    1993-06-01

    A variety of advanced bioreactors are being developed to improve production of fuels, solvents, organic acids and other fermentation products. One key approach is immobilization of the biocatalyst leading to increased rates and yields. In addition, there are processes for simultaneous fermentation and separation to further increase production by the removal of an inhibitory product. For example, ethanol productivity in immobilized-cell fluidized-bed bioreactors (FBRs) can increase more than tenfold with 99% conversion and near stoichiometric yields. Two modified FBR configurations offer further improvements by removing the inhibitory product directly from the continuous fermentation. One involves the addition and removal of solid adsorbent particles to the FBR. This process was demonstrated with the production of lactic acid by immobilized Lactobacillus. The second uses an immiscible organic extractant in the FBR. This increased total butanol yields in the anaerobic acetone-butanol fermentation by Clostridium acetobutylicum.

  3. A comparative study of distortion-product-otoacoustic-emission fine structure in human newborns and adults with normal hearing.

    PubMed

    Dhar, Sumitrajit; Abdala, Carolina

    2007-10-01

    Distortion product otoacoustic emissions (DPOAE) measured in human newborns are not adult-like. More than a decade of work from various investigators has created a well-developed body of evidence describing these differences but the putative anatomy or physiology has only been partially explained. Recently, Abdala and Keefe [J. Acoust. Soc. Am. 120, 3832-3842 (2006)] have identified outer and middle ear immaturities that at least partially describe the differences observed between newborn and adult input-output functions and suppression tuning curves. DPOAE fine structure characteristics and their maturation have not been examined to any extent in the literature. Fine structure characteristics in two groups of ten newborns and young adults with normal hearing sensitivity are compared here. Consistent with previous reports, the newborns show higher DPOAE levels; greater fine structure depth and wider fine structure spacing is also observed in the newborns. Differences in fine structure morphology are also observed between the two age groups. While some of these findings are attributable to an immature outer and middle ear system in the newborns, it is argued that some observed differences in fine structure characteristics might be due to remnant immaturities in passive motion of the basilar membrane in the newborn cochlea.

  4. Advanced bioreactors for enhanced production of chemicals

    SciTech Connect

    Davison, B.H.

    1993-12-31

    A variety of advanced bioreactors are being developed to improve production of fuels, solvents, organic acids, and other fermentation products. One key approach is immobilization of the biocatalyst, leading to increased rates and yields. In addition, there are processes for simultaneous fermentation and separation to further increase production. For example, ethanol productivity in immobilized-cell fluidized-bed bioreactors (FBRs) can increase more than tenfold with 99% conversion and near stoichiometric yields. Two modified FBR configurations offer further improvements by removing the inhibitory product directly from the continuous fermentation. One involves the addition and removal of solid adsorbent particles to the FBR. This process was demonstrated with the production of lactic acid by immobilized Lactobacillus. The second uses an immiscible organic extractant in the FBR. This increased total butanol yields in the anaerobic acetone-butanol fermentation by Clostridium acetobutylicum.

  5. Clarifying the chemical state of additives in membranes for polymer electrolyte fuel cells by X-ray absorption fine structure

    NASA Astrophysics Data System (ADS)

    Tanuma, Toshihiro; Itoh, Takanori

    2016-02-01

    Cerium and manganese compounds are used in the membrane for polymer electrolyte fuel cells (PEFCs) as radical scavengers to mitigate chemical degradation of the membrane. The chemical states of cerium and manganese in the membrane were investigated using a fluorescence X-ray absorption fine structure (XAFS) technique. Membrane electrode assemblies (MEAs) were subjected to open circuit voltage (OCV) condition, under which hydroxyl radicals attack the membrane; a shift in absorption energy in X-ray absorption near edge structure (XANES) spectra was compared between Ce- and Mn-containing membranes before and after OCV testing. In the case of the Ce-containing MEA, there was no significant difference in XANES spectra before and after OCV testing, whereas in the case of the Mn-containing MEA, there was an obvious shift in XANES absorption energy after OCV testing, indicating that Mn atoms with higher valence state than 2+ exist in the membrane after OCV testing. This can be attributed to the difference in the rate of reduction; the reaction of Ce4+ with ·OOH is much faster than that of Mn3+ with ·OOH, leaving some of the Mn atoms with higher valence state. It was confirmed that cerium and manganese redox couples reduced the attack from radicals, mitigating membrane degradation.

  6. Mercury Speciation by X-ray Absorption Fine Structure Spectroscopy and Sequential Chemical Extractions: A Comparison of Speciation Methods

    USGS Publications Warehouse

    Kim, C.S.; Bloom, N.S.; Rytuba, J.J.; Brown, Gordon E.

    2003-01-01

    Determining the chemical speciation of mercury in contaminated mining and industrial environments is essential for predicting its solubility, transport behavior, and potential bioavailability as well as for designing effective remediation strategies. In this study, two techniques for determining Hg speciation-X-ray absorption fine structure (XAFS) spectroscopy and sequential chemical extractions (SCE)-are independently applied to a set of samples with Hg concentrations ranging from 132 to 7539 mg/kg to determine if the two techniques provide comparable Hg speciation results. Generally, the proportions of insoluble HgS (cinnabar, metacinnabar) and HgSe identified by XAFS correlate well with the proportion of Hg removed in the aqua regia extraction demonstrated to remove HgS and HgSe. Statistically significant (> 10%) differences are observed however in samples containing more soluble Hg-containing phases (HgCl2, HgO, Hg3S2O 4). Such differences may be related to matrix, particle size, or crystallinity effects, which could affect the apparent solubility of Hg phases present. In more highly concentrated samples, microscopy techniques can help characterize the Hg-bearing species in complex multiphase natural samples.

  7. CHEMICALS FROM PHARMACEUTICALS AND PERSONAL CARE PRODUCTS

    EPA Science Inventory

    The use or consumption of natural resources often leads to ecological alteration. These changes can result from exposure of living systems to "stressors" ranging from physical alteration (such as habitat disruption) to chemical pollution. Untoward effects on wildlife and humans c...

  8. Chemical composition of fat and oil products

    USDA-ARS?s Scientific Manuscript database

    Fats and oils are an important dietary component, and contribute to the nutritional and sensory quality of foods. This chapter focuses on the chemical composition of fats and oils, and how these compositions affect the functional properties of fats and oils in foods. The focus will remain on the mos...

  9. The Microbiological Production of Industrial Chemicals.

    ERIC Educational Resources Information Center

    Eveleigh, Douglas E.

    1981-01-01

    Compares traditional and newer methods by which microorganisms are used to produce industrial chemicals. Includes a discussion of economic considerations and new genetic methods in programing microorganisms. Details methods for producing enzymes, aliphatic organic compounds, amino acids, ethanol, n-butanol, and alkene oxides. (CS)

  10. CHEMICALS FROM PHARMACEUTICALS AND PERSONAL CARE PRODUCTS

    EPA Science Inventory

    The use or consumption of natural resources often leads to ecological alteration. These changes can result from exposure of living systems to "stressors" ranging from physical alteration (such as habitat disruption) to chemical pollution. Untoward effects on wildlife and humans c...

  11. The Microbiological Production of Industrial Chemicals.

    ERIC Educational Resources Information Center

    Eveleigh, Douglas E.

    1981-01-01

    Compares traditional and newer methods by which microorganisms are used to produce industrial chemicals. Includes a discussion of economic considerations and new genetic methods in programing microorganisms. Details methods for producing enzymes, aliphatic organic compounds, amino acids, ethanol, n-butanol, and alkene oxides. (CS)

  12. Chemical composition and source of fine and nanoparticles from recent direct injection gasoline passenger cars: Effects of fuel and ambient temperature

    NASA Astrophysics Data System (ADS)

    Fushimi, Akihiro; Kondo, Yoshinori; Kobayashi, Shinji; Fujitani, Yuji; Saitoh, Katsumi; Takami, Akinori; Tanabe, Kiyoshi

    2016-01-01

    Particle number, mass, and chemical compositions (i.e., elemental carbon (EC), organic carbon (OC), elements, ions, and organic species) of fine particles emitted from four of the recent direct injection spark ignition (DISI) gasoline passenger cars and a port fuel injection (PFI) gasoline passenger car were measured under Japanese official transient mode (JC08 mode). Total carbon (TC = EC + OC) dominated the particulate mass (90% on average). EC dominated the TC for both hot and cold start conditions. The EC/TC ratios were 0.72 for PFI and 0.88-1.0 (average = 0.92) for DISI vehicles. A size-resolved chemical analysis of a DISI car revealed that the major organic components were the C20-C28 hydrocarbons for both the accumulation-mode particles and nanoparticles. Contribution of engine oil was estimated to be 10-30% for organics and the sum of the measured elements. The remaining major fraction likely originated from gasoline fuel. Therefore, it is suggested that soot (EC) also mainly originated from the gasoline. In experiments using four fuels at three ambient temperatures, the emission factors of particulate mass were consistently higher with regular gasoline than with premium gasoline. This result suggest that the high content of less-volatile compounds in fuel increase particulate emissions. These results suggest that focusing on reducing fuel-derived EC in the production process of new cars would effectively reduce particulate emission from DISI cars.

  13. Fine Root Growth Phenology, Production, and Turnover in a Northern Hardwood Forest Ecosystem

    Treesearch

    Marianne K. Burke; Dudley J. Raynal

    1994-01-01

    A large part of the nutrient flux in deciduous forests is through fine root turnover, yet this process is seldom measured. As part of a nutrient cycling study, fine root dynamics were studied for two years at Huntington Forest in the Adirondack Mountain region of New York, USA. Root growth phenology was characterized using field rhizotrons, three methods were used to...

  14. 25 CFR 309.22 - What are examples of painting and other fine art forms that are Indian products?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... but, not limited to, works on canvas, photography, sand painting, mural, computer generated art... 25 Indians 2 2010-04-01 2010-04-01 false What are examples of painting and other fine art forms that are Indian products? 309.22 Section 309.22 Indians INDIAN ARTS AND CRAFTS BOARD, DEPARTMENT OF...

  15. Chemical compositions of fine particulate organic matter emitted from Chinese cooking.

    PubMed

    Zhao, Yunliang; Hu, Min; Slanina, Sjaak; Zhang, Yuanhang

    2007-01-01

    Food cooking can be a significant source of atmospheric particulate organic matter. In this study, the chemical composition of particulate organic matter (POM) in PM2.5 emitted from four different Chinese cooking styles were examined by gas chromotography-mass spectrometry (GC-MS). The identified species are consistent in the emissions from different Chinese cooking styles and the quantified compounds account for 5-10% of total POM in PM2.5. The dominant homologue is fatty acids, constituting 73-85% of the quantified compounds. The pattern of n-alkanes and the presence of beta-sitosterol and levoglucosan indicate that vegetables are consumed during Chinese cooking operations. Furthermore, the emissions of different compounds are impacted significantly by the cooking ingredients. The candidates of organic tracers used to describe and distinguish emissions from Chinese cooking in Guangzhou are tetradecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, levoglucosan, mannosan, galactosan, nonanal, and lactones. During the sampling period, the relative contribution of Chinese cooking to the mass concentration of atmospheric hexadecanoic acid should be less than 1.3% in Guangzhou.

  16. Electrifying microbes for the production of chemicals.

    PubMed

    Tremblay, Pier-Luc; Zhang, Tian

    2015-01-01

    Powering microbes with electrical energy to produce valuable chemicals such as biofuels has recently gained traction as a biosustainable strategy to reduce our dependence on oil. Microbial electrosynthesis (MES) is one of the bioelectrochemical approaches developed in the last decade that could have critical impact on the current methods of chemical synthesis. MES is a process in which electroautotrophic microbes use electrical current as electron source to reduce CO2 to multicarbon organics. Electricity necessary for MES can be harvested from renewable resources such as solar energy, wind turbine, or wastewater treatment processes. The net outcome is that renewable energy is stored in the covalent bonds of organic compounds synthesized from greenhouse gas. This review will discuss the future of MES and the challenges that lie ahead for its development into a mature technology.

  17. Electrifying microbes for the production of chemicals

    PubMed Central

    Tremblay, Pier-Luc; Zhang, Tian

    2015-01-01

    Powering microbes with electrical energy to produce valuable chemicals such as biofuels has recently gained traction as a biosustainable strategy to reduce our dependence on oil. Microbial electrosynthesis (MES) is one of the bioelectrochemical approaches developed in the last decade that could have critical impact on the current methods of chemical synthesis. MES is a process in which electroautotrophic microbes use electrical current as electron source to reduce CO2 to multicarbon organics. Electricity necessary for MES can be harvested from renewable resources such as solar energy, wind turbine, or wastewater treatment processes. The net outcome is that renewable energy is stored in the covalent bonds of organic compounds synthesized from greenhouse gas. This review will discuss the future of MES and the challenges that lie ahead for its development into a mature technology. PMID:25814988

  18. Chemical Characterization and Source Apportionment of Indoor and Outdoor Fine Particulate Matter (PM2.5) in Retirement Communities of the Los Angeles Basin

    PubMed Central

    Hasheminassab, Sina; Daher, Nancy; Shafer, Martin M.; Schauer, James J.; Delfino, Ralph J.; Sioutas, Constantinos

    2014-01-01

    Concurrent indoor and outdoor measurements of fine particulate matter (PM2.5) were conducted at three retirement homes in the Los Angeles Basin during two separate phases (cold and warm) between 2005 and 2006. Indoor-to-outdoor relationships of PM2.5 chemical constituents were determined and sources of indoor and outdoor PM2.5 were evaluated using a molecular marker-based chemical mass balance (MM-CMB) model. Indoor levels of elemental carbon (EC) along with metals and trace elements were found to be significantly affected by outdoor sources. EC, in particular, displayed very high indoor-to-outdoor (I/O) mass ratios accompanied by strong I/O correlations, illustrating the significant impact of outdoor sources on indoor levels of EC. Similarly, indoor levels of polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes were strongly correlated with their outdoor components and displayed I/O ratios close to unity. On the other hand, concentrations of n-alkanes and organic acids inside the retirement communities were dominated by indoor sources (e.g. food cooking and consumer products), as indicated by their I/O ratios, which exceeded unity. Source apportionment results revealed that vehicular emissions were the major contributor to both indoor and outdoor PM2.5, accounting for 39 and 46% of total mass, respectively. Moreover, the contribution of vehicular sources to indoor levels was generally comparable to its corresponding outdoor estimate. Other water-insoluble organic matter (other WIOM), which accounts for emissions from uncharacterized primary biogenic sources, displayed a wider range of contributions, varying from 2 to 73% of PM2.5, across all sites and phases of the study. Lastly, higher indoor than outdoor contribution of other water-soluble organic matter (other WSOM) was evident at some of the sites, suggesting the production of secondary aerosols as well as direct emissions from primary sources (including cleaning or other consumer products) at the

  19. Chemical Composition and Emission Sources of the Fine Particulate Matters in a Southeast Asian Mega City (Dhaka, Bangladesh)

    NASA Astrophysics Data System (ADS)

    Salam, Abdus

    2016-04-01

    Air pollution has significant impact on human health, climate change, agriculture, visibility reduction, and also on the atmospheric chemistry. There are many studies already reported about the direct relation of the human mortality and morbidity with the increase of the atmospheric particulate matters. Especially, fine particulate matters can easily enter into the human respiratory system and causes many diseases. Particulate matters have the properties to absorb the solar radiation and impact on the climate. Dhaka, Bangladesh is a densely populated mega-city in the world. About 16 million inhabitants are living within an area of 360 square kilometers. Air quality situation has been degrading due to unplanned growth, increasing vehicles, severe traffic jams, brick kilns, industries, construction, and also transboundary air pollution. A rapidly growing number of vehicles has worsen the air quality in spite of major policy interventions, e.g., ban of two-stroke and three-wheeled vehicles, phase out of 20 years old vehicles, conversion to compressed natural gas (CNGs), etc. Introduction of CNGs to reduce air pollution was not the solution for fine particles at all, as evidence shows that CNGs and diesel engines are the major sources of fine particles. High concentration of the air pollutants in Dhaka city such as PM, carbonaceous species (black and organic carbon), CO, etc. has already been reported. PM2.5 mass, chemical composition (e.g., BC, OC, SO42-, NO3-, trace elements, etc.), aerosol Optical Depth (AOD) and emission sources of our recent measurements at the highly polluted south East Asian Mega city (Dhaka) Bangladesh will be presented in the conference. PM2.5 samples were collected on filters with Digital PM2.5 sampler (Switzerland) and Air photon, USA. BC was measured from filters (with thermal and optical method) and also real time with an Aethalometer AE42 (Magee Scitific., USA). Water soluble ions were determined from filters with ion chromatogram. AOD

  20. Chemical Adulterants in Herbal Medicinal Products: A Review.

    PubMed

    Calahan, Jacob; Howard, Dylan; Almalki, Ahmad J; Gupta, Mahabir P; Calderón, Angela I

    2016-04-01

    Many herbal medicinal products have been found to contain synthetic prescription drugs as chemical adulterants. This has become evident by the number of toxicity cases and adverse reactions reported in which casualties were reported via analytical techniques that detected the presence of chemical adulterants in them, which could be responsible for their toxicity. The adulteration of herbal medicinal products with synthetic drugs continues to be a serious problem for regulatory agencies. This review provides up to date information on cases of toxicity, major chemical adulterants in herbal medicinal products, and current analytical techniques used for their detection.

  1. Biotechnology for Chemical Production: Challenges and Opportunities.

    PubMed

    Burk, Mark J; Van Dien, Stephen

    2016-03-01

    Biotechnology offers a new sustainable approach to manufacturing chemicals, enabling the replacement of petroleum-based raw materials with renewable biobased feedstocks, thereby reducing greenhouse gas (GHG) emissions, toxic byproducts, and the safety risks associated with traditional petrochemical processing. Development of such bioprocesses is enabled by recent advances in genomics, molecular biology, and systems biology, and will continue to accelerate as access to these tools becomes faster and cheaper.

  2. Commercial production of specialty chemicals and pharmaceuticals from biomass

    SciTech Connect

    McChesney, J.D.

    1993-12-31

    The chemical substances utilized in consumer products, and for pharmaceutical and agricultural uses are generally referred to as specialty chemicals. These may be flavor or fragrance substances, intermediates for synthesis of drugs or agrochemicals or the drugs or agrochemicals themselves, insecticides or insect pheromones or antifeedants, plant growth regulators, etc. These are in contrast to chemicals which are utilized in large quantities for fuels or preparation of plastics, lubricants, etc., which are usually referred to as industrial chemicals. The specific utilization of specialty chemicals is associated with a specific important physiochemical or biological property. They may possess unique properties as lubricants or waxes or have a very desirable biological activity such as a drug, agrochemical or perfume ingredient. These unique properties convey significant economic value to the specific specialty chemical. The economic commercial production of specialty chemicals commonly requires the isolation of a precursor or the specialty chemical itself from a natural source. The discovery, development and commercialization of specialty chemicals is presented and reviewed. The economic and sustainable production of specialty chemicals is discussed.

  3. Processing of waste material of radix physochlainae for preparation of fine chemicals after extraction

    NASA Astrophysics Data System (ADS)

    He, A.; Yohannes, A.; Feng, X. T.; Yao, S.

    2017-02-01

    Waste residues of Chinese traditional medicine radix physochlainae (Huashanshen) contain a large amount of hemicelluloses after extraction. After the removal of the cellulose and lignin, main components of the solution are different degree of hydrolysis products of hemicelluloses. In the degradation process, hemicelluloses firstly become pentose, and then pentose loses 3 molecules of water and turns into furfural. This study explored a series of conditions of the method; finally the yield of furfural can reach 8.5% (calculated with the weight of raw residues) under the condition of pH of 0.2-0.3, temperature of 104-106°C, hydrolysis duration for 10 minutes. Furfural can be further processed to be resin materials.

  4. Sustainability of biofuels and renewable chemicals production from biomass.

    PubMed

    Kircher, Manfred

    2015-12-01

    In the sectors of biofuel and renewable chemicals the big feedstock demand asks, first, to expand the spectrum of carbon sources beyond primary biomass, second, to establish circular processing chains and, third, to prioritize product sectors exclusively depending on carbon: chemicals and heavy-duty fuels. Large-volume production lines will reduce greenhouse gas (GHG) emission significantly but also low-volume chemicals are indispensable in building 'low-carbon' industries. The foreseeable feedstock change initiates innovation, securing societal wealth in the industrialized world and creating employment in regions producing biomass. When raising the investments in rerouting to sustainable biofuel and chemicals today competitiveness with fossil-based fuel and chemicals is a strong issue. Many countries adopted comprehensive bioeconomy strategies to tackle this challenge. These public actions are mostly biased to biofuel but should give well-balanced attention to renewable chemicals as well.

  5. Fine Root Productivity and Turnover of Ectomycorrhizal and Arbuscular Mycorrhizal Tree Species in a Temperate Broad-Leaved Mixed Forest

    PubMed Central

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2016-01-01

    Advancing our understanding of tree fine root dynamics is of high importance for tree physiology and forest biogeochemistry. In temperate broad-leaved forests, ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) tree species often are coexisting. It is not known whether EM and AM trees differ systematically in fine root dynamics and belowground resource foraging strategies. We measured fine root productivity (FRP) and fine root turnover (and its inverse, root longevity) of three EM and three AM broad-leaved tree species in a natural cool-temperate mixed forest using ingrowth cores and combined the productivity data with data on root biomass per root orders. FRP and root turnover were related to root morphological traits and aboveground productivity. FRP differed up to twofold among the six coexisting species with larger species differences in lower horizons than in the topsoil. Root turnover varied up to fivefold among the species with lowest values in Acer pseudoplatanus and highest in its congener Acer platanoides. Variation in root turnover was larger within the two groups than between EM and AM species. We conclude that the main determinant of FRP and turnover in this mixed forest is species identity, while the influence of mycorrhiza type seems to be less important. PMID:27617016

  6. Chemical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3

    EPA Science Inventory

    This paper addresses the need for detailed chemical information on the fine particulate matter (PM2.5) generated by commercial aviation engines. The exhaust plumes of nine engine models were sampled during the three test campaigns of the Aircraft Particle Emissions eXperiment (AP...

  7. Chemical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3

    EPA Science Inventory

    This paper addresses the need for detailed chemical information on the fine particulate matter (PM2.5) generated by commercial aviation engines. The exhaust plumes of nine engine models were sampled during the three test campaigns of the Aircraft Particle Emissions eXperiment (AP...

  8. Perspectives of Using Ultra-Fine Metals as Universal Safe BioStimulators to Get Cattle Breeding Quality Products

    NASA Astrophysics Data System (ADS)

    Polishchuk, S.

    2015-11-01

    We have conducted investigations of ultra-fine metals biological activity with lab non-pedigree white rats, rabbits breed “Soviet chinchilla” and cattle young stock of the black and white breed as the most widely spread in the central part of Russia. One can see the possibility of using microelements of ultra-fine iron, cobalt and copper as cheap, non-toxic and highly effective biological catalyst of biochemical processes in the organism that improve physiological state, morphological and biochemical blood parameters increasing activity of the experimental animals’ ferment systems and their productivity and meat biological value. We have proved the ultra-fine powders safety when adding them to the animals’ diet.

  9. Cyanobacterial chassis engineering for enhancing production of biofuels and chemicals.

    PubMed

    Gao, Xinyan; Sun, Tao; Pei, Guangsheng; Chen, Lei; Zhang, Weiwen

    2016-04-01

    To reduce dependence on fossil fuels and curb greenhouse effect, cyanobacteria have emerged as an important chassis candidate for producing biofuels and chemicals due to their capability to directly utilize sunlight and CO2 as the sole energy and carbon sources, respectively. Recent progresses in developing and applying various synthetic biology tools have led to the successful constructions of novel pathways of several dozen green fuels and chemicals utilizing cyanobacterial chassis. Meanwhile, it is increasingly recognized that in order to enhance productivity of the synthetic cyanobacterial systems, optimizing and engineering more robust and high-efficient cyanobacterial chassis should not be omitted. In recent years, numerous research studies have been conducted to enhance production of green fuels and chemicals through cyanobacterial chassis modifications involving photosynthesis, CO2 uptake and fixation, products exporting, tolerance, and cellular regulation. In this article, we critically reviewed recent progresses and universal strategies in cyanobacterial chassis engineering to make it more robust and effective for bio-chemicals production.

  10. EFFECTS OF ENVIRONMENTAL CHEMICALS ON FETAL TESTES TESTOSTERONE PRODUCTION

    EPA Science Inventory

    Effects of Environmental Chemicals on Fetal Testes Testosterone Production

    Lambright, CS , Wilson, VS , Furr, J, Wolf, CJ, Noriega, N, Gray, LE, Jr.
    US EPA, ORD/NHEERL/RTD, RTP, NC

    Exposure of pregnant rodents to certain environmental chemicals during criti...

  11. EFFECTS OF ENVIRONMENTAL CHEMICALS ON FETAL TESTES TESTOSTERONE PRODUCTION

    EPA Science Inventory

    Effects of Environmental Chemicals on Fetal Testes Testosterone Production

    Lambright, CS , Wilson, VS , Furr, J, Wolf, CJ, Noriega, N, Gray, LE, Jr.
    US EPA, ORD/NHEERL/RTD, RTP, NC

    Exposure of pregnant rodents to certain environmental chemicals during criti...

  12. The Changing Landscape of Hydrocarbon Feedstocks for Chemical Production: Implications for Catalysis: Proceedings of a Workshop

    SciTech Connect

    Bell, Alexis T.; Alger, Monty M.; Flytzani-Stephanopoulos, Maria; Gunnoe, T. Brent; Lercher, Johannes A.; Stevens, James; Alper, Joe; Tran, Camly

    2016-11-14

    A decade ago, the U.S. chemical industry was in decline. Of the more than 40 chemical manufacturing plants being built worldwide in the mid-2000s with more than $1 billion in capitalization, none were under construction in the United States. Today, as a result of abundant domestic supplies of affordable natural gas and natural gas liquids resulting from the dramatic rise in shale gas production, the U.S. chemical industry has gone from the world’s highest-cost producer in 2005 to among the lowest-cost producers today. The low cost and increased supply of natural gas and natural gas liquids provides an opportunity to discover and develop new catalysts and processes to enable the direct conversion of natural gas and natural gas liquids into value-added chemicals with a lower carbon footprint. The economic implications of developing advanced technologies to utilize and process natural gas and natural gas liquids for chemical production could be significant, as commodity, intermediate, and fine chemicals represent a higher-economic-value use of shale gas compared with its use as a fuel. To better understand the opportunities for catalysis research in an era of shifting feedstocks for chemical production and to identify the gaps in the current research portfolio, the National Academies of Sciences, Engineering, and Medicine conducted an interactive, multidisciplinary workshop in March 2016. The goal of this workshop was to identify advances in catalysis that can enable the United States to fully realize the potential of the shale gas revolution for the U.S. chemical industry and, as a result, to help target the efforts of U.S. researchers and funding agencies on those areas of science and technology development that are most critical to achieving these advances. This publication summarizes the presentations and discussions from the workshop.

  13. Chemical Composition of Defatted Cottonseed and Soy Meal Products

    PubMed Central

    He, Zhongqi; Zhang, Hailin; Olk, Dan C.

    2015-01-01

    Chemical composition is critical information for product quality and exploration of new use. Hence defatted cottonseed meals from both glanded (with gossypol) and glandless (without gossypol) cotton seeds were separated into water soluble and insoluble fractions, or water soluble, alkali soluble as well as total protein isolates. The contents of gossypol, total protein and amino acids, fiber and carbohydrates, and selected macro and trace elements in these products were determined and compared with each other and with those of soy meal products. Data reported in this work improved our understanding on the chemical composition of different cottonseed meal products that is helpful for more economical utilization of these products. These data would also provide a basic reference for product standards and quality control when the production of the cottonseed meal products comes to pilot and industrial scales. PMID:26079931

  14. Chemical characteristics and source apportionment of indoor and outdoor fine particles observed in an urban environment in Korea

    NASA Astrophysics Data System (ADS)

    Heo, J.; Yi, S. M.

    2016-12-01

    Paired indoor-outdoor fine particulate matter (PM2.5) samples were collected at subway stations, underground shopping centers, and schools in Seoul metropolitan over a 4-year period between 2004 and 2007. Relationships between indoor and outdoor PM2.5 chemical species were determined and source contributions to indoor and outdoor PM2.5 mass were estimated using a positive matrix factorization (PMF) model. The PM2.5 samples were analyzed for major chemical components including organic carbon and elemental carbon, ions, and metals, and the results were used in the PMF model. The levels of the PM2.5 mass and its chemical components observed at the indoor sites were higher than those at the outdoor sites. Indoor levels of ions (i.e. sulfate, nitrate, ammonium), elemental carbon, and several metals (i.e. Fe, Zn, and Cu) were found to be significantly affected by outdoor sources. Very high indoor-to-outdoor mass ratio of these chemical components, in particular, were observed, representing the significant impacts of outdoor sources on indoor levels of them. Seven sources (secondary sulfate, secondary nitrate, mobile, biomass burning, roadway emissions, dust, and sea salt) were resolved by the PMF model at both of the indoor and outdoor sites. The secondary inorganic aerosol (i.e. secondary sulfate and nitrate) and the mobile sources were major contributors to the indoor and outdoor PM2.5, accounting for 47% and 27% of the outdoor PM2.5 and 40% and 25% of the indoor PM2.5, respectively. Furthermore, the contributions of the secondary inorganic aerosol and the mobile sources to the indoor PM2.5 were very comparable to its corresponding contributions to the outdoor PM2.5 levels. The spatial and temporal characteristics of each of sources resolved by the PMF model across the sites were examined using summary statistics, correlation analysis, and coefficient of variation and divergence analysis and the detailed results will be discussed in the presentation.

  15. Intercomparison of an Aerosol Chemical Speciation Monitor (ACSM) with ambient fine aerosol measurements in downtown Atlanta, Georgia

    NASA Astrophysics Data System (ADS)

    Budisulistiorini, S. H.; Canagaratna, M. R.; Croteau, P. L.; Baumann, K.; Edgerton, E. S.; Kollman, M. S.; Ng, N. L.; Verma, V.; Shaw, S. L.; Knipping, E. M.; Worsnop, D. R.; Jayne, J. T.; Weber, R. J.; Surratt, J. D.

    2014-07-01

    Currently, there are a limited number of field studies that evaluate the long-term performance of the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) against established monitoring networks. In this study, we present seasonal intercomparisons of the ACSM with collocated fine aerosol (PM2.5) measurements at the Southeastern Aerosol Research and Characterization (SEARCH) Jefferson Street (JST) site near downtown Atlanta, GA, during 2011-2012. Intercomparison of two collocated ACSMs resulted in strong correlations (r2 > 0.8) for all chemical species, except chloride (r2 = 0.21) indicating that ACSM instruments are capable of stable and reproducible operation. In general, speciated ACSM mass concentrations correlate well (r2 > 0.7) with the filter-adjusted continuous measurements from JST, although the correlation for nitrate is weaker (r2 = 0.55) in summer. Correlations of the ACSM NR-PM1 (non-refractory particulate matter with aerodynamic diameter less than or equal to 1 μm) plus elemental carbon (EC) with tapered element oscillating microbalance (TEOM) PM2.5 and Federal Reference Method (FRM) PM1 mass are strong with r2 > 0.7 and r2 > 0.8, respectively. Discrepancies might be attributed to evaporative losses of semi-volatile species from the filter measurements used to adjust the collocated continuous measurements. This suggests that adjusting the ambient aerosol continuous measurements with results from filter analysis introduced additional bias to the measurements. We also recommend to calibrate the ambient aerosol monitoring instruments using aerosol standards rather than gas-phase standards. The fitting approach for ACSM relative ionization for sulfate was shown to improve the comparisons between ACSM and collocated measurements in the absence of calibrated values, suggesting the importance of adding sulfate calibration into the ACSM calibration routine.

  16. Chemical composition of fine particles in fresh smoke plumes from boreal wild-land fires in Europe.

    PubMed

    Saarnio, Karri; Aurela, Minna; Timonen, Hilkka; Saarikoski, Sanna; Teinilä, Kimmo; Mäkelä, Timo; Sofiev, Mikhail; Koskinen, Jarkko; Aalto, Pasi P; Kulmala, Markku; Kukkonen, Jaakko; Hillamo, Risto

    2010-05-15

    A series of smoke plumes was detected in Helsinki, Finland, during a one-month-lasting period in August 2006. The smoke plumes originated from wildfires close to Finland, and they were short-term and had a high particulate matter (PM) concentration. Physical and chemical properties of fine particles in those smokes were characterised by a wide range of real-time measurements that enabled the examination of individual plume events. Concurrently PM(1) filter samples were collected and analysed off-line. Satellite observations employing MODIS sensor on board of NASA EOS Terra satellite with the dispersion model SILAM and the Fire Assimilation System were used for evaluation of the emission fluxes from wildfires. The model predicted well the timing of the plumes but the predicted PM concentrations differed from the observed. The measurements showed that the major growth in PM concentration was caused by submicrometer particles consisting mainly of particulate organic matter (POM). POM had not totally oxidised during the transport based on the low WSOC-to-OC ratio. The fresh plumes were compared to another major smoke episode that was observed in Helsinki during April-May 2006. The duration and the source areas of the two episode periods differed. The episode in April-May was a period of nearly constantly upraised level of long-range transported PM and it was composed of aged particles when arriving in Helsinki. The two episodes had differences also in the chemical composition of PM. The mass concentrations of biomass burning tracers (levoglucosan, potassium, and oxalate) increased during both the episodes but different concentration levels of elemental carbon and potassium indicated that the episodes differed in the form of burning as well as in the burning material. In spring dry crop residue and hay from the previous season were burnt whereas in August smokes from smouldering and incomplete burning of fresh vegetation were detected.

  17. Spatial and Temporal Variation in Fine Particulate Matter Mass and Chemical Composition: The Middle East Consortium for Aerosol Research Study

    PubMed Central

    Abdeen, Ziad; Heo, Jongbae; Wu, Bo; Shpund, Jacob; Vanger, Arye; Sharf, Geula; Moise, Tamar; Brenner, Shmuel; Nassar, Khaled; Saleh, Rami; Al-Mahasneh, Qusai M.; Sarnat, Jeremy A.; Schauer, James J.

    2014-01-01

    Ambient fine particulate matter (PM2.5) samples were collected from January to December 2007 to investigate the sources and chemical speciation in Palestine, Jordan, and Israel. The 24-h PM2.5 samples were collected on 6-day intervals at eleven urban and rural sites simultaneously. Major chemical components including metals, ions, and organic and elemental carbon were analyzed. The mass concentrations of PM2.5 across the 11 sites varied from 20.6 to 40.3 μg/m3, with an average of 28.7 μg/m3. Seasonal variation of PM2.5 concentrations was substantial, with higher average concentrations (37.3 μg/m3) in the summer (April–June) months compared to winter (October–December) months (26.0 μg/m3) due mainly to high contributions of sulfate and crustal components. PM2.5 concentrations in the spring were greatly impacted by regional dust storms. Carbonaceous mass was the most abundant component, contributing 40% to the total PM2.5 mass averaged across the eleven sites. Crustal components averaged 19.1% of the PM2.5 mass and sulfate, ammonium, and nitrate accounted for 16.2%, 6.4%, and 3.7%, respectively, of the total PM2.5 mass. The results of this study demonstrate the need to better protect the health and welfare of the residents on both sides of the Jordan River in the Middle East. PMID:25045751

  18. Spatial and temporal variation in fine particulate matter mass and chemical composition: the Middle East Consortium for Aerosol Research Study.

    PubMed

    Abdeen, Ziad; Qasrawi, Radwan; Heo, Jongbae; Wu, Bo; Shpund, Jacob; Vanger, Arye; Sharf, Geula; Moise, Tamar; Brenner, Shmuel; Nassar, Khaled; Saleh, Rami; Al-Mahasneh, Qusai M; Sarnat, Jeremy A; Schauer, James J

    2014-01-01

    Ambient fine particulate matter (PM2.5) samples were collected from January to December 2007 to investigate the sources and chemical speciation in Palestine, Jordan, and Israel. The 24-h PM2.5 samples were collected on 6-day intervals at eleven urban and rural sites simultaneously. Major chemical components including metals, ions, and organic and elemental carbon were analyzed. The mass concentrations of PM2.5 across the 11 sites varied from 20.6 to 40.3 μg/m(3), with an average of 28.7 μg/m(3). Seasonal variation of PM2.5 concentrations was substantial, with higher average concentrations (37.3 μg/m(3)) in the summer (April-June) months compared to winter (October-December) months (26.0 μg/m(3)) due mainly to high contributions of sulfate and crustal components. PM2.5 concentrations in the spring were greatly impacted by regional dust storms. Carbonaceous mass was the most abundant component, contributing 40% to the total PM2.5 mass averaged across the eleven sites. Crustal components averaged 19.1% of the PM2.5 mass and sulfate, ammonium, and nitrate accounted for 16.2%, 6.4%, and 3.7%, respectively, of the total PM2.5 mass. The results of this study demonstrate the need to better protect the health and welfare of the residents on both sides of the Jordan River in the Middle East.

  19. ASSESSING THE EFFECTS OF ELEVATED ATMOSP;HERIC CO2 AND TEMPERATURE ON FINE ROOT PRODUCTION AND MORTALITY IN FORESTED SYSTEMS

    EPA Science Inventory

    Little is known about the effects of global climate change on the production and mortality of fine roots. To better understand these processes we have conducted a number of studies to investigate the factors that influence the production and mortality of fine roots in coniferous...

  20. ASSESSING THE EFFECTS OF ELEVATED ATMOSP;HERIC CO2 AND TEMPERATURE ON FINE ROOT PRODUCTION AND MORTALITY IN FORESTED SYSTEMS

    EPA Science Inventory

    Little is known about the effects of global climate change on the production and mortality of fine roots. To better understand these processes we have conducted a number of studies to investigate the factors that influence the production and mortality of fine roots in coniferous...

  1. Chemical production on Mars using in situ propellant production technology

    NASA Technical Reports Server (NTRS)

    Ash, Robert L.

    1986-01-01

    In situ propellant production (ISPP) was examined in terms of its applicability to a manned Mars mission. Production of oxygen from Martian atmosphere was used as the baseline system for ISPP technology assessment. It was concluded that production of oxygen was an important element in a manned Mars mission which could be developed in terrestrial laboratories. Expert system methodology will be required to enable reliable, autonomous production of oxygen. Furthermore, while no major technical breakthroughs are required, this research requires a long lead time to permit its systematic evolution.

  2. A review of selected chemical additives in cosmetic products.

    PubMed

    Juhász, Margit Lai Wun; Marmur, Ellen S

    2014-01-01

    The addition of chemical additives to consumer cosmetic products is a common practice to increase cosmetic effectiveness, maintain cosmetic efficacy, and produce a longer-lasting, more viable product. Recently, manufacturers have come under attack for the addition of chemicals including dioxane, formaldehyde, lead/lead acetate, parabens, and phthalate, as these additives may prove harmful to consumer health. Although reports show that these products may indeed adversely affect human health, these studies are conducted using levels of the aforementioned chemicals at much higher levels of exposure than those found in cosmetic products. When cosmeceuticals are used as per manufacturer's instructions, it is estimated that the levels of harmful additives found in these products are considerably lower than reported toxic concentrations. © 2014 Wiley Periodicals, Inc.

  3. 75 FR 8575 - Testing of Certain High Production Volume Chemicals; Third Group of Chemicals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

    ...EPA is proposing a test rule under section 4(a)(1)(B) of the Toxic Substances Control Act (TSCA) that would require manufacturers, importers, and processors of certain high production volume (HPV) chemicals to conduct testing to obtain screening level data for health and environmental effects and chemical fate.

  4. Cyanobacterial metabolic engineering for biofuel and chemical production.

    PubMed

    Oliver, Neal J; Rabinovitch-Deere, Christine A; Carroll, Austin L; Nozzi, Nicole E; Case, Anna E; Atsumi, Shota

    2016-12-01

    Rising levels of atmospheric CO2 are contributing to the global greenhouse effect. Large scale use of atmospheric CO2 may be a sustainable and renewable means of chemical and liquid fuel production to mitigate global climate change. Photosynthetic organisms are an ideal platform for efficient, natural CO2 conversion to a broad range of chemicals. Cyanobacteria are especially attractive for these purposes, due to their genetic malleability and relatively fast growth rate. Recent years have yielded a range of work in the metabolic engineering of cyanobacteria and have led to greater knowledge of the host metabolism. Understanding of endogenous and heterologous carbon regulation mechanisms leads to the expansion of productive capacity and chemical variety. This review discusses the recent progress in metabolic engineering of cyanobacteria for biofuel and bulk chemical production since 2014.

  5. Chemical characterization and sources of personal exposure to fine particulate matter in the general population of Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Cui; Jahn, Heiko J.; Engling, Guenter; Ward, Tony J.; Kraemer, Alexander; Ho, Kin-Fai; Hung-Lam Yim, Steve; Chan, Chuen-Yu

    2017-04-01

    Fine particulate matter pollution severely deteriorates the environmental conditions and negatively impacts human health in the Chinese megacity Guangzhou. Concurrent ambient and personal measurements of fine particulate matter (PM2.5) were conducted in Guangzhou, China. Personal-to-ambient (P-C) relationships of PM2.5 chemical components were determined and sources of personal PM2.5 exposure were evaluated using principal component analysis along with a mixed-effects model. Water-soluble inorganic ions (mainly secondary inorganic ions) and anhydrosugars exhibited median personal-to-ambient (P/C) ratios < 1 accompanied by strong P-C correlations, indicating that these constituents in personal PM2.5 were significantly affected by ambient sources. Conversely, elemental carbon (EC) and calcium (Ca2+) showed median P/C ratios greater than unity, which indicated that among subjects who spent a great amount of time indoors, aside from particles of ambient origin, individual's total exposure to PM2.5 includes contributions of non-ambient exposure while indoors and outdoors (e.g., local traffic, indoor sources, personal activities). SO42- displayed very low coefficient of divergence (COD) values coupled with strong P-C correlations, implying a uniform distribution of SO42- in the urban area of Guangzhou. EC, Ca2+, and levoglucosan were otherwise heterogeneously distributed across individuals in different districts. Regional air pollution (50.4 ± 0.9%), traffic-related particles (8.6 ± 0.7%), dust-related particles (5.8 ± 0.7%), and biomass burning emissions (2.0 ± 0.2%) were moderate to high positive sources of personal PM2.5 exposure in Guangzhou. The observed positive and significant contribution of Ca2+ to personal PM2.5 exposure, highlighting indoor sources and/or personal activities, were driving factors determining personal exposure to dust-related particles. Considerable discrepancies (COD values ranging from 0.42 to 0.50) were shown between ambient

  6. Fine and coarse particulate matter chemical characterization in a heavily industrialized city in central Mexico during Winter 2003.

    PubMed

    Vega, Elizabeth; Ruiz, Hugo; Martínez-Villa, Gerardo; Sosa, Gustavo; González-Avalos, Eugenio; Reyes, Elizabeth; García, José

    2007-05-01

    This paper presents the results of the first reported study on fine particulate matter (PM) chemical composition at Salamanca, a highly industrialized urban area of Central Mexico. Samples were collected at six sites within the urban area during February and March 2003. Several trace elements, organic carbon (OC), elemental carbon (EC), and six ions were analyzed to characterize aerosols. Average concentrations of PM with aerodynamic diameter of less than 10 microm (PM10) and fine PM with aerodynamic diameter of less than 2.5 microm (PM2.5) ranged from 32.2 to 76.6 [g m(-3) and 11.1 to 23.7 microg m(-3), respectively. OC (34%), SO4= (25.1%), EC (12.9%), and geological material (12.5%) were the major components of PM2.5. For PM10 geological material (57.9%), OC (17.3%), and SO4= (9.7%) were the major components. Coarse fraction (PM,, -PM2.5), geological material (81.7%), and OC (8.6%) were the dominant species, which amounted to 90.4%. Correlation analysis showed that sulfate in PM2.5 was present as ammonium sulfate. Sulfate showed a significant spatial variation with higher concentrations to the north resulting from predominantly southwesterly winds above the surface layer and by major SO2 sources that include a power plant and refinery. At the urban site of Cruz Roja it was observed that PM2.5 mass concentrations were similar to the submicron fraction concentrations. Furthermore, the correlation between EC in PM2.5 and EC measured from an aethalometer was r(2) = 0.710. Temporal variations of SO2 and nitrogen oxide were observed during a day when the maximum concentration of PM2.5 was measured, which was associated with emissions from the nearby refinery and power plant. From cascade impactor measurements, the three measured modes of airborne particles corresponded with diameters of 0.32, 1.8, and 5.6 microm.

  7. Role of natural product diversity in chemical biology.

    PubMed

    Hong, Jiyong

    2011-06-01

    Through the natural selection process, natural products possess a unique and vast chemical diversity and have been evolved for optimal interactions with biological macromolecules. Owing to their diversity, target affinity, and specificity, natural products have demonstrated enormous potential as modulators of biomolecular function, been an essential source for drug discovery, and provided design principles for combinatorial library development.

  8. Chemical factors affecting fission product transport in severe LMFBR accidents

    SciTech Connect

    Wichner, R.P.; Jolley, R.L.; Gat, U.; Rodgers, B.R.

    1984-10-01

    This study was performed as a part of a larger evaluation effort on LMFBR accident, source-term estimation. Purpose was to provide basic chemical information regarding fission product, sodium coolant, and structural material interactions required to perform estimation of fission product transport under LMFBR accident conditions. Emphasis was placed on conditions within the reactor vessel; containment vessel conditions are discussed only briefly.

  9. Identification and chemical characterization of specific organic indicators in the effluents from chemical production sites.

    PubMed

    Botalova, Oxana; Schwarzbauer, Jan; al Sandouk, Nadia

    2011-06-01

    The structural diversity of the wastewater composition was described by the use of detailed non-target screening analyses of industrial effluents from chemical production sites. Determination of the indicative organic compounds acting as potential molecular indicators for industrial emissions from chemical production industries has been possible due to (i) detailed characterisation of industrial contaminants and identification of compounds with high source specificity, (ii) quantitative determination of the organic constituents in the industrial effluents and (iii) the review of their industrial applications. The determination of potential site-specific markers and industrial molecular indicators corresponding to certain production processes (production of starting materials for manufacturing paper and printing inks, powder coatings as well as epichlorohydrin production) was performed in this work. The results of this study allowed significant contributions to the chemical characterisation of industrial contaminants and isolation of indicators that can act as representatives of industrial effluents in the aquatic environment.

  10. Chemical state of fission products in irradiated uranium carbide fuel

    NASA Astrophysics Data System (ADS)

    Arai, Yasuo; Iwai, Takashi; Ohmichi, Toshihiko

    1987-12-01

    The chemical state of fission products in irradiated uranium carbide fuel has been estimated by equilibrium calculation using the SOLGASMIX-PV program. Solid state fission products are distributed to the fuel matrix, ternary compounds, carbides of fission products and intermetallic compounds among the condensed phases appearing in the irradiated uranium carbide fuel. The chemical forms are influenced by burnup as well as stoichiometry of the fuel. The results of the present study almost agree with the experimental ones reported for burnup simulated carbides.

  11. Heterogeneous Nucleation of Trichloroethylene Ozonation Products in the Formation of New Fine Particles

    NASA Astrophysics Data System (ADS)

    Wang, Ning; Sun, Xiaomin; Chen, Jianmin; Li, Xiang

    2017-02-01

    Free radicals in atmosphere have played an important role in the atmospheric chemistry. The chloro-Criegee free radicals are produced easily in the decomposition of primary ozonide (POZ) of the trichloroethylene, and can react with O2, NO, NO2, SO2 and H2O subsequently. Then the inorganic salts, polar organic nitrogen and organic sulfur compounds, oxygen-containing heterocyclic intermediates and polyhydroxy compounds can be obtained. The heterogeneous nucleation of oxidation intermediates in the formation of fine particles is investigated using molecular dynamics simulation. The detailed nucleation processes are reported. According to molecular dynamics simulation, the nucleation with a diameter of 2 nm is formed in the Organic Compounds-(NH4)2SO4-H2O system. The spontaneous nucleation is an important process in the formation of fine particles in atmosphere. The model study gives a good example from volatile organic compounds to new fine particles.

  12. Heterogeneous Nucleation of Trichloroethylene Ozonation Products in the Formation of New Fine Particles

    PubMed Central

    Wang, Ning; Sun, Xiaomin; Chen, Jianmin; Li, Xiang

    2017-01-01

    Free radicals in atmosphere have played an important role in the atmospheric chemistry. The chloro-Criegee free radicals are produced easily in the decomposition of primary ozonide (POZ) of the trichloroethylene, and can react with O2, NO, NO2, SO2 and H2O subsequently. Then the inorganic salts, polar organic nitrogen and organic sulfur compounds, oxygen-containing heterocyclic intermediates and polyhydroxy compounds can be obtained. The heterogeneous nucleation of oxidation intermediates in the formation of fine particles is investigated using molecular dynamics simulation. The detailed nucleation processes are reported. According to molecular dynamics simulation, the nucleation with a diameter of 2 nm is formed in the Organic Compounds-(NH4)2SO4-H2O system. The spontaneous nucleation is an important process in the formation of fine particles in atmosphere. The model study gives a good example from volatile organic compounds to new fine particles. PMID:28198438

  13. Date fruit: chemical composition, nutritional and medicinal values, products.

    PubMed

    Tang, Zhen-Xing; Shi, Lu-E; Aleid, Salah M

    2013-08-15

    Date fruit has served as a staple food in the Arab world for centuries. Worldwide production of date fruit has increased almost threefold over the last 40 years, reaching 7.68 million tons in 2010. Date fruit can provide many essential nutrients and potential health benefits to the consumer. Date fruit goes through four ripening stages named kimri, khalal, rutab and tamer. The main chemical components of date fruit include carbohydrates, dietary fibre, enzymes, protein, fat, minerals, vitamins, phenolic acids and carotenoids. The chemical composition of date fruit varies according to ripening stage, cultivar, growing environment, postharvest conditions, etc. The nutritional and medicinal activities of date fruit are related to its chemical composition. Many studies have shown that date fruit has antioxidant, antimutagenic, anti-inflammatory, gastroprotective, hepatoprotective, nephroprotective, anticancer and immunostimulant activities. Various date fruit-based products such as date syrup, date paste, date juice and their derived products are available. Date by-products can be used as raw materials for the production of value-added products such as organic acids, exopolysaccharides, antibiotics, date-flavoured probiotic-fermented dairy produce, bakery yeasts, etc. In this paper the chemical composition and nutritional and medicinal values of date fruit as well as date fruit-based products are reviewed.

  14. Fluidized-Bed Particles Scavenge Silicon Fines

    NASA Technical Reports Server (NTRS)

    Hsu, G. C.; Rohatgi, N.; Lutwack, R.; Hogle, R.

    1985-01-01

    Waste reduced, and silicon production rate improved. In new process silicon formed by thermal decomposition of SiH4. Part of silicon formed on silicon seed particles as result of surface chemical reaction. However, silicon formed by homogeneous reaction in gas phase tends to form aggregates of silicon atoms, which appear as fine particles (like dust). Believed that scavenging action of seed particles enables large fraction fines to be incorporated onto seed surface. This mode of growth confirmed by electron microscopy photographs.

  15. Fine particulate matter source apportionment for the Chemical speciation Trends Network site at Birmingham, Alabama, using Positive Matrix Factorization.

    PubMed

    Baumann, Karsten; Jayanty, R K M; Flanagan, James B

    2008-01-01

    The Positive Matrix Factorization (PMF) receptor model version 1.1 was used with data from the fine particulate matter (PM2.5) Chemical Speciation Trends Network (STN) to estimate source contributions to ambient PM2.5 in a highly industrialized urban setting in the southeastern United States. Model results consistently resolved 10 factors that are interpreted as two secondary, five industrial, one motor vehicle, one road dust, and one biomass burning sources. The STN dataset is generally not corrected for field blank levels, which are significant in the case of organic carbon (OC). Estimation of primary OC using the elemental carbon (EC) tracer method applied on a seasonal basis significantly improved the model's performance. Uniform increase of input data uncertainty and exclusion of a few outlier samples (associated with high potassium) further improved the model results. However, it was found that most PMF factors did not cleanly represent single source types and instead are "contaminated" by other sources, a situation that might be improved by controlling rotational ambiguity within the model. Secondary particulate matter formed by atmospheric processes, such as sulfate and secondary OC, contribute the majority of ambient PM2.5 and exhibit strong seasonality (37 +/- 10% winter vs. 55 +/- 16% summer average). Motor vehicle emissions constitute the biggest primary PM2.5 mass contribution with almost 25 +/- 2% long-term average and winter maximum of 29 +/- 11%. PM2.5 contributions from the five identified industrial sources vary little with season and average 14 +/- 1.3%. In summary, this study demonstrates the utility of the EC tracer method to effectively blank-correct the OC concentrations in the STN dataset. In addition, examination of the effect of input uncertainty estimates on model results indicates that the estimated uncertainties currently being provided with the STN data may be somewhat lower than the levels needed for optimum modeling results.

  16. Characterization of chemical composition and concentration of fine particulate matter during a transit strike in Ottawa, Canada

    NASA Astrophysics Data System (ADS)

    Ding, Luyi; Chan, Tak Wai; Ke, Fu; Wang, Daniel K. W.

    2014-06-01

    From December 10, 2008 to February 9, 2009, a strike stopped the public transit services in Ottawa, Ontario, Canada. To understand the changes in air quality associated with the transit strike, the chemical composition and concentration of the fine particulate matter with diameters less than 2.5 microns (PM2.5), collected before, during, and after the transit strike period, were evaluated. The collected PM2.5 samples were analyzed to determine the particulate matter mass, the levels of organic carbon (OC) and elemental carbon (EC), as well as the particulate non-polar semi-volatiles, e.g., polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes. Particle number size distributions measured during and after the transit strike period were also compared. Results indicated that during transit strike months, particle number size distributions were entirely dominated by nucleation mode particles leading to an increase in total particle number concentration by about 79%. In addition, particulate matter, organic carbon, and elemental carbon mass concentrations also increased by over 100%. The average total PAH levels during the strike months were higher by a factor of about 7. Elevated concentrations of high molecular weight PAHs (i.e., PAH with 5 and 6 rings) observed during the strike months suggested that there were more gasoline-powered vehicles on the roads over that period. The level of carcinogenic benzo[a]pyrene was higher by a factor of 5. Mass concentrations of hopanes and steranes were 30-98% higher during the strike months than non-strike months and exhibited strong correlations with EC suggesting the primary origin of these compounds. These results indicated that the increased traffic volume due to the passenger vehicles and the change in driving pattern during the transit strike period reduced the local air quality.

  17. SEASONAL PATTERNS OF FINE ROOT PRODUCTION AND TURNOVER IN PONDEROSA PINE STANDS OF DIFFERENT AGES

    EPA Science Inventory

    Root minirhizotron tubes were installed in two ponderosa pine (Pinus ponderosa Laws.) stands around three different tree age classes (16, 45, and > 250 yr old) to examine root spatial distribution in relation to canopy size and tree distribution, and to determine if rates of fine...

  18. Egg Production Constrains Chemical Defenses in a Neotropical Arachnid

    PubMed Central

    Nazareth, Taís M.; Machado, Glauco

    2015-01-01

    Female investment in large eggs increases the demand for fatty acids, which are allocated for yolk production. Since the biosynthetic pathway leading to fatty acids uses the same precursors used in the formation of polyketides, allocation trade-offs are expected to emerge. Therefore, egg production should constrain the investment in chemical defenses based on polyketides, such as benzoquinones. We tested this hypothesis using the harvestman Acutiosoma longipes, which produces large eggs and releases benzoquinones as chemical defense. We predicted that the amount of secretion released by ovigerous females (OFs) would be smaller than that of non-ovigerous females (NOF). We also conducted a series of bioassays in the field and in the laboratory to test whether egg production renders OFs more vulnerable to predation. OFs produce less secretion than NOFs, which is congruent with the hypothesis that egg production constrains the investment in chemical defenses. Results of the bioassays show that the secretion released by OFs is less effective in deterring potential predators (ants and spiders) than the secretion released by NOFs. In conclusion, females allocate resources to chemical defenses in a way that preserves a primary biological function related to reproduction. However, the trade-off between egg and secretion production makes OFs vulnerable to predators. We suggest that egg production is a critical moment in the life of harvestman females, representing perhaps the highest cost of reproduction in the group. PMID:26331946

  19. Intercomparison of an Aerosol Chemical Speciation Monitor (ACSM) with ambient fine aerosol measurements in Downtown Atlanta, Georgia

    NASA Astrophysics Data System (ADS)

    Budisulistiorini, S. H.; Canagaratna, M. R.; Croteau, P. L.; Baumann, K.; Edgerton, E. S.; Kollman, M. S.; Ng, N. L.; Verma, V.; Shaw, S. L.; Knipping, E. M.; Worsnop, D. R.; Jayne, J. T.; Weber, R. J.; Surratt, J. D.

    2013-12-01

    The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) was recently developed to provide long-term real-time continuous measurements of ambient non-refractory (i.e., organic, sulfate, ammonium, nitrate, and chloride) submicron particulate matter (NR-PM1). Currently, there are a limited number of field studies that evaluate the long-term performance of the ACSM against established monitoring networks. In this study, we present seasonal intercomparisons of the ACSM with collocated fine aerosol (PM2.5) measurements at the Southeastern Aerosol Research and Characterization (SEARCH) Jefferson Street (JST) site near downtown Atlanta, GA, during 2011-2012. The collocated measurements included a second ACSM, continuous and integrated sulfate, nitrate, and ammonium measurements, as well as a semi-continuous Sunset organic carbon/elemental carbon (OC/EC) analyzer, continuous tapered element oscillating microbalance (TEOM), 24 h integrated Federal Reference Method (FRM) filters, and continuous scanning electrical mobility system-mixing condensation particle counter (SEMS-MCPC). Intercomparison of the two collocated ACSMs resulted in strong correlations (r2 > 0.8) for all chemical species, except chloride (r2 = 0.21); mass concentration for all chemical species agreed within ±27%, indicating that ACSM instruments are capable of stable and reproducible operation. Chemical constituents measured by the ACSM are also compared with those obtained from the continuous measurements from JST. Since the continuous measurement concentrations are adjusted to match the integrated filter measurements, these comparisons reflect the combined uncertainties of the ACSM, continuous, and filter measurements. In general, speciated ACSM mass concentrations correlate well (r2 > 0.7) with the continuous measurements from JST, although the correlation for nitrate is weaker (r2 = 0.55) in summer. Differences between ACSM mass concentrations and the filter-adjusted JST continuous data are 5-27%, 4

  20. Why Leading Consumer Product Companies Develop Proactive Chemical Management Strategies.

    PubMed

    Scruggs, Caroline E; Van Buren, Harry J

    2016-05-01

    Scholars have studied the various pressures that companies face related to socially responsible behavior when stakeholders know the particular social issues under consideration. Many have examined social responsibility in the context of environmental responsibility and the general approaches companies take regarding environmental management. The issue of currently unregulated, but potentially hazardous, chemicals in consumer products is not well understood by the general public, but a number of proactive consumer product companies have voluntarily adopted strategies to minimize use of such chemicals. These companies are exceeding regulatory requirements by restricting from their products chemicals that could harm human or environmental health, despite the fact that these actions are costly. They do not usually advertise the details of their strategies to end consumers. This article uses interviews with senior environmental directors of 20 multinational consumer product companies to investigate why these companies engage in voluntary chemicals management. The authors conclude that the most significant reasons are to achieve a competitive advantage and stay ahead of regulations, manage relationships and maintain legitimacy with stakeholders, and put managerial values into practice. Many of the characteristics related to the case of chemicals management are extendable to other areas of stakeholder management in which risks to stakeholders are either unknown or poorly understood.

  1. Why Leading Consumer Product Companies Develop Proactive Chemical Management Strategies

    PubMed Central

    Scruggs, Caroline E.; Van Buren, Harry J.

    2014-01-01

    Scholars have studied the various pressures that companies face related to socially responsible behavior when stakeholders know the particular social issues under consideration. Many have examined social responsibility in the context of environmental responsibility and the general approaches companies take regarding environmental management. The issue of currently unregulated, but potentially hazardous, chemicals in consumer products is not well understood by the general public, but a number of proactive consumer product companies have voluntarily adopted strategies to minimize use of such chemicals. These companies are exceeding regulatory requirements by restricting from their products chemicals that could harm human or environmental health, despite the fact that these actions are costly. They do not usually advertise the details of their strategies to end consumers. This article uses interviews with senior environmental directors of 20 multinational consumer product companies to investigate why these companies engage in voluntary chemicals management. The authors conclude that the most significant reasons are to achieve a competitive advantage and stay ahead of regulations, manage relationships and maintain legitimacy with stakeholders, and put managerial values into practice. Many of the characteristics related to the case of chemicals management are extendable to other areas of stakeholder management in which risks to stakeholders are either unknown or poorly understood. PMID:27471326

  2. Chemical characterization and source apportionment of indoor and outdoor fine particulate matter (PM(2.5)) in retirement communities of the Los Angeles Basin.

    PubMed

    Hasheminassab, Sina; Daher, Nancy; Shafer, Martin M; Schauer, James J; Delfino, Ralph J; Sioutas, Constantinos

    2014-08-15

    Concurrent indoor and outdoor measurements of fine particulate matter (PM2.5) were conducted at three retirement homes in the Los Angeles Basin during two separate phases (cold and warm) between 2005 and 2006. Indoor-to-outdoor relationships of PM2.5 chemical constituents were determined and sources of indoor and outdoor PM2.5 were evaluated using a molecular marker-based chemical mass balance (MM-CMB) model. Indoor levels of elemental carbon (EC) along with metals and trace elements were found to be significantly affected by outdoor sources. EC, in particular, displayed very high indoor-to-outdoor (I/O) mass ratios accompanied by strong I/O correlations, illustrating the significant impact of outdoor sources on indoor levels of EC. Similarly, indoor levels of polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes were strongly correlated with their outdoor components and displayed I/O ratios close to unity. On the other hand, concentrations of n-alkanes and organic acids inside the retirement communities were dominated by indoor sources (e.g. food cooking and consumer products), as indicated by their I/O ratios, which exceeded unity. Source apportionment results revealed that vehicular emissions were the major contributor to both indoor and outdoor PM2.5, accounting for 39 and 46% of total mass, respectively. Moreover, the contribution of vehicular sources to indoor levels was generally comparable to its corresponding outdoor estimate. Other water-insoluble organic matter (other WIOM), which accounts for emissions from uncharacterized primary biogenic sources, displayed a wider range of contributions, varying from 2 to 73% of PM2.5, across all sites and phases of the study. Lastly, higher indoor than outdoor contribution of other water-soluble organic matter (other WSOM) was evident at some of the sites, suggesting the production of secondary aerosols as well as direct emissions from primary sources (including cleaning or other consumer products) at the

  3. Enhanced production of α-form indomethacin using the antisolvent crystallization method assisted by N2 fine bubbles

    NASA Astrophysics Data System (ADS)

    Matsumoto, Masakazu; Ohno, Masatoshi; Wada, Yoshinari; Sato, Toshiyuki; Okada, Masaki; Hiaki, Toshihiko

    2017-07-01

    In this study, using the gas-liquid interfaces near fine bubbles as new crystallization fields where nucleation proceeds dominantly, a crystallization technique to enhance the production of α-form Indomethacin (IMC) at a constant temperature was developed. IMC is reported to show a complicated polymorphism that consists of five true polymorphs and a wide range of solvate forms, which are collectively named the β-form. IMC was crystallized using the antisolvent method assisted by nitrogen (N2) fine bubbles. In the regions around the minute gas-liquid interfaces, local supersaturation increases because of the accumulation of IMC, which is caused by the negative electric charge on the fine-bubble surface. Hence, the rate of crystal nucleation increases, and the crystallization of metastable polymorph is enhanced. At a solution temperature of 298 K, a saturated IMC-EtOH solution and water as an antisolvent were mixed by two different addition orders, as follows: the IMC-EtOH/H2O system: water was quickly added into a saturated IMC-EtOH solution; the H2O/IMC-EtOH system: a saturated IMC-EtOH solution was rapidly added into water. While water was mixed with the saturated IMC-EtOH solution, N2 fine bubbles with an average diameter of 25 μm were continuously supplied to the mixed solution using a self-supporting bubble generator and IMC was crystallized within a crystallization time of 5 min. In both systems, the supersaturation ratio in the bulk solution (lnC0/CS) was varied in the range of 1.5-5.7 by controlling the addition volume of water or saturated IMC-EtOH solution. For comparison, antisolvent crystallization free of fine bubbles was performed. The results show that in both systems, N2 fine-bubble injection enhanced the production of metastable α-form at ln(C0/CS) below 3.5, and decreased the required ln(C0/CS) for the high-yield crystallization of α-form.

  4. Production of pig iron from red mud waste fines using thermal plasma technology

    NASA Astrophysics Data System (ADS)

    Jayasankar, K.; Ray, P. K.; Chaubey, A. K.; Padhi, A.; Satapathy, B. K.; Mukherjee, P. S.

    2012-08-01

    Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite (fixed carbon, 99%) as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.

  5. Metabolic engineering of yeast for production of fuels and chemicals.

    PubMed

    Nielsen, Jens; Larsson, Christer; van Maris, Antonius; Pronk, Jack

    2013-06-01

    Microbial production of fuels and chemicals from renewable carbohydrate feedstocks offers sustainable and economically attractive alternatives to their petroleum-based production. The yeast Saccharomyces cerevisiae offers many advantages as a platform cell factory for such applications. Already applied on a huge scale for bioethanol production, this yeast is easy to genetically engineer, its physiology, metabolism and genetics have been intensively studied and its robustness enables it to handle harsh industrial conditions. Introduction of novel pathways and optimization of its native cellular processes by metabolic engineering are rapidly expanding its range of cell-factory applications. Here we review recent scientific progress in metabolic engineering of S. cerevisiae for the production of bioethanol, advanced biofuels, and chemicals. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Source apportionment of ambient fine particulate matter in Dearborn, Michigan, using hourly resolved PM chemical composition data.

    PubMed

    Pancras, Joseph Patrick; Landis, Matthew S; Norris, Gary A; Vedantham, Ram; Dvonch, J Timothy

    2013-03-15

    High time-resolution aerosol sampling was conducted for one month during July-August 2007 in Dearborn, MI, a non-attainment area for fine particulate matter (PM2.5) National Ambient Air Quality Standards (NAAQS). Measurements of more than 30 PM2.5 species were made using a suite of semi-continuous sampling and monitoring instruments. Dynamic variations in the sub-hourly concentrations of source 'marker' elements were observed when discrete plumes from local sources impacted the sampling site. Hourly averaged PM2.5 composition data for 639 samples were used to identify and apportion PM2.5 emission sources using the multivariate receptor modeling techniques EPA Positive Matrix Factorization (PMF) v4.2 and EPA Unmix v6.0. Source contribution estimates from PMF and Unmix were then evaluated using the Sustained Wind Instance Method (SWIM), which identified plausible source origins. Ten sources were identified by both PMF and Unmix: (1) secondary sulfate, (2) secondary nitrate characterized by a significant diurnal trend, (3) iron and steel production, (4) a potassium-rich factor attributable to iron/steel slag waste processing, (5) a cadmium-rich factor attributable to incineration, (6) an oil refinery characterized by La/Ce>1 specific to south wind, (7) oil combustion, (8) coal combustion, (9) motor vehicles, and (10) road dust enriched with organic carbon. While both models apportioned secondary sulfate, oil refinery, and oil combustion PM2.5 masses closely, the mobile and industrial source apportionments differed. Analyses were also carried out to help infer time-of-day variations in the contributions of local sources.

  7. Production of bulk chemicals via novel metabolic pathways in microorganisms.

    PubMed

    Shin, Jae Ho; Kim, Hyun Uk; Kim, Dong In; Lee, Sang Yup

    2013-11-01

    Metabolic engineering has been playing important roles in developing high performance microorganisms capable of producing various chemicals and materials from renewable biomass in a sustainable manner. Synthetic and systems biology are also contributing significantly to the creation of novel pathways and the whole cell-wide optimization of metabolic performance, respectively. In order to expand the spectrum of chemicals that can be produced biotechnologically, it is necessary to broaden the metabolic capacities of microorganisms. Expanding the metabolic pathways for biosynthesizing the target chemicals requires not only the enumeration of a series of known enzymes, but also the identification of biochemical gaps whose corresponding enzymes might not actually exist in nature; this issue is the focus of this paper. First, pathway prediction tools, effectively combining reactions that lead to the production of a target chemical, are analyzed in terms of logics representing chemical information, and designing and ranking the proposed metabolic pathways. Then, several approaches for potentially filling in the gaps of the novel metabolic pathway are suggested along with relevant examples, including the use of promiscuous enzymes that flexibly utilize different substrates, design of novel enzymes for non-natural reactions, and exploration of hypothetical proteins. Finally, strain optimization by systems metabolic engineering in the context of novel metabolic pathways constructed is briefly described. It is hoped that this review paper will provide logical ways of efficiently utilizing 'big' biological data to design and develop novel metabolic pathways for the production of various bulk chemicals that are currently produced from fossil resources.

  8. Optimization of enzyme parameters for fermentative production of biorenewable fuels and chemicals.

    PubMed

    Jarboe, Laura R; Liu, Ping; Kautharapu, Kumar Babu; Ingram, Lonnie O

    2012-01-01

    Microbial biocatalysts such as Escherichia coli and Saccharomyces cerevisiae have been extensively subjected to Metabolic Engineering for the fermentative production of biorenewable fuels and chemicals. This often entails the introduction of new enzymes, deletion of unwanted enzymes and efforts to fine-tune enzyme abundance in order to attain the desired strain performance. Enzyme performance can be quantitatively described in terms of the Michaelis-Menten type parameters Km, turnover number kcat and Ki, which roughly describe the affinity of an enzyme for its substrate, the speed of a reaction and the enzyme sensitivity to inhibition by regulatory molecules. Here we describe examples of where knowledge of these parameters have been used to select, evolve or engineer enzymes for the desired performance and enabled increased production of biorenewable fuels and chemicals. Examples include production of ethanol, isobutanol, 1-butanol and tyrosine and furfural tolerance. The Michaelis-Menten parameters can also be used to judge the cofactor dependence of enzymes and quantify their preference for NADH or NADPH. Similarly, enzymes can be selected, evolved or engineered for the preferred cofactor preference. Examples of exporter engineering and selection are also discussed in the context of production of malate, valine and limonene.

  9. Optimization of enzyme parameters for fermentative production of biorenewable fuels and chemicals

    PubMed Central

    Jarboe, Laura R.; Liu, Ping; Kautharapu, Kumar Babu; Ingram, Lonnie O.

    2012-01-01

    Microbial biocatalysts such as Escherichia coli and Saccharomyces cerevisiae have been extensively subjected to Metabolic Engineering for the fermentative production of biorenewable fuels and chemicals. This often entails the introduction of new enzymes, deletion of unwanted enzymes and efforts to fine-tune enzyme abundance in order to attain the desired strain performance. Enzyme performance can be quantitatively described in terms of the Michaelis-Menten type parameters Km, turnover number kcat and Ki, which roughly describe the affinity of an enzyme for its substrate, the speed of a reaction and the enzyme sensitivity to inhibition by regulatory molecules. Here we describe examples of where knowledge of these parameters have been used to select, evolve or engineer enzymes for the desired performance and enabled increased production of biorenewable fuels and chemicals. Examples include production of ethanol, isobutanol, 1-butanol and tyrosine and furfural tolerance. The Michaelis-Menten parameters can also be used to judge the cofactor dependence of enzymes and quantify their preference for NADH or NADPH. Similarly, enzymes can be selected, evolved or engineered for the preferred cofactor preference. Examples of exporter engineering and selection are also discussed in the context of production of malate, valine and limonene. PMID:24688665

  10. Response of the Fine Root Production, Phenology, and Turnover Rate of Six Shrub Species from a Subtropical Forest to a Soil Moisture Gradient and Shading

    NASA Astrophysics Data System (ADS)

    Fu, X.; Dai, X.; Wang, H.

    2015-12-01

    Knowledge of the fine root dynamics of different life forms in forest ecosystems is critical to understanding how the overall belowground carbon cycling is affected by climate change. However, our current knowledge regarding how endogenous or exogenous factors regulate the root dynamics of understory vegetation is limited. We selected a suite of study sites representing different habitats with gradients of soil moisture and solar radiation (shading or no shading). We assessed the fine root production phenology, the total fine root production, and the turnover among six understory shrub species in a subtropical climate, and examined the responses of the fine root dynamics to gradients in the soil moisture and solar radiation. The shrubs included three evergreen species, Loropetalum chinense, Vaccinium bracteatum, and Adinandra millettii, and three deciduous species, Serissa serissoides, Rubus corchorifolius, and Lespedeza davidii. We observed that variations in the annual fine root production and turnover among species were significant in the deciduous group but not in the evergreen group. Notably, V. bracteatum and S. serissoides presented the greatest responses in terms of root phenology to gradients in the soil moisture and shading: high-moisture habitat led to a decrease and shade led to an increase in fine root production during spring. Species with smaller fine roots of the 1st+2nd-order diameter presented more sensitive responses in terms of fine root phenology to a soil moisture gradient. Species with a higher fine root nitrogen-to -carbon ratio exhibited more sensitive responses in terms of fine root annual production to shading. Soil moisture and shading did not change the annual fine root production as much as the turnover rate. The fine root dynamics of some understory shrubs varied significantly with soil moisture and solar radiation status and may be different from tree species. Our results emphasize the need to study the understory fine root dynamics

  11. Chemical state of fission products in irradiated UO 2

    NASA Astrophysics Data System (ADS)

    Imoto, S.

    1986-08-01

    The chemical state of fission products in irradiated UO 2 fuel has been estimated for FBR as well as LWR on the basis of equilibrium calculation with the SOLGASMIX-PV code. The system considered for the calculation is composed of a gas phase, a CaF 2 type oxide phase, three grey phases, a noble metal alloy, a mixed telluride phase and several other phases each consisting of single compound. The distribution of elements into these phases and the amount of chemical species in each phase at different temperatures are obtained as a function of oxygen potential for LWR and FBR. Changes of the chemical potential of the fuel-fission products system during burnup are also evaluated with particular attention to the difference between LWR and FBR. Some informations obtained by the calculation are compared with the results of post irradiation examination of UO 2 fuels.

  12. Size distribution of chemical elements and their source apportionment in ambient coarse, fine, and ultrafine particles in Shanghai urban summer atmosphere.

    PubMed

    Lü, Senlin; Zhang, Rui; Yao, Zhenkun; Yi, Fei; Ren, Jingjing; Wu, Minghong; Feng, Man; Wang, Qingyue

    2012-01-01

    Ambient coarse particles (diameter 1.8-10 microm), fine particles (diameter 0.1-1.8 microm), and ultrafine particles (diameter < 0.1 microm) in the atmosphere of the city of Shanghai were sampled during the summer of 2008 (from Aug 27 to Sep 08). Microscopic characterization of the particles was investigated by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX). Mass concentrations of Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr, and Pb in the size-resolved particles were quantified by using synchrotron radiation X-ray fluorescence (SRXRF). Source apportionment of the chemical elements was analyzed by means of an enrichment factor method. Our results showed that the average mass concentrations of coarse particles, fine particles and ultrafine particles in the summer air were 9.38 +/- 2.18, 8.82 +/- 3.52, and 2.02 +/- 0.41 microg/m3, respectively. The mass percentage of the fine particles accounted for 51.47% in the total mass of PM10, indicating that fine particles are the major component in the Shanghai ambient particles. SEM/EDX results showed that the coarse particles were dominated by minerals, fine particles by soot aggregates and fly ashes, and ultrafine particles by soot particles and unidentified particles. SRXRF results demonstrated that crustal elements were mainly distributed in the coarse particles, while heavy metals were in higher proportions in the fine particles. Source apportionment revealed that Si, K, Ca, Fe, Mn, Rb, and Sr were from crustal sources, and S, Cl, Cu, Zn, As, Se, Br, and Pb from anthropogenic sources. Levels of P, V, Cr, and Ni in particles might be contributed from multi-sources, and need further investigation.

  13. Record of Some Chemical Residues in Poultry Products

    ERIC Educational Resources Information Center

    Stadelman, W. J.

    1973-01-01

    How pesticides, polychlorinated biphenyls, and heavy metals might get into poultry meat or eggs is reviewed. Several case studies where chemicals were found in poultry products are discussed. It can be concluded that the poultry industry is striving and generally succeeding in producing safe and nutritious meat and eggs. (Author/EB)

  14. Record of Some Chemical Residues in Poultry Products

    ERIC Educational Resources Information Center

    Stadelman, W. J.

    1973-01-01

    How pesticides, polychlorinated biphenyls, and heavy metals might get into poultry meat or eggs is reviewed. Several case studies where chemicals were found in poultry products are discussed. It can be concluded that the poultry industry is striving and generally succeeding in producing safe and nutritious meat and eggs. (Author/EB)

  15. Chemical composition of defatted cottonseed and soy meal products

    USDA-ARS?s Scientific Manuscript database

    Chemical composition is critical information for product quality and exploration of new use. Hence defatted cottonseed meals from both glanded (with gossypol) and glandless (without gossypol) cotton seeds were separated into water soluble and insoluble fractions, or water soluble, alkali soluble as ...

  16. Measurements of in situ chemical ozone (oxidant) production rates

    NASA Astrophysics Data System (ADS)

    Huang, Hao; Faloon, Kate; Najera, Juan; Bloss, William

    2013-04-01

    Tropospheric ozone is a major air pollutant, harmful to human health, agricultural crops and vegetation, the main precursor to the atmospheric oxidants which initiate the degradation of most reactive gases emitted to the atmosphere, and an important greenhouse gas in its own right. The capacity to understand and predict tropospheric ozone levels is a key goal for atmospheric science - but one which is challenging, as ozone is formed in the atmosphere from the complex oxidation of VOCs in the presence of NOx and sunlight, on a timescale such that in situ chemical processes, deposition and transport all affect ozone levels. Known uncertainties in emissions, chemistry, dynamics and deposition affect the accuracy of predictions of current and future ozone levels, and hinder development of optimal air quality policies to mitigate against ozone exposure. Recently new approaches to directly measure the local chemical ozone production rate, bypassing the many uncertainties in emissions and chemical schemes, have been developed (Cazorla & Brune, AMT 2010). Here, we describe the development of an analogous Ozone Production Rate (OPR) approach: Air is sampled into parallel reactors, within which ozone formation either occurs as in the ambient atmosphere, or is suppressed. Comparisons of ozone levels exiting a pair of such reactors determines the net chemical oxidant production rate, after correction for perturbation of the NOx-O3 photochemical steady state, and when operated under conditions such that wall effects are minimised. We report preliminary measurements of local chemical ozone production made during the UK NERC ClearfLo (Clean Air for London) campaign at an urban background location in London in January and July 2012. The OPR system was used to measure the local chemical oxidant formation rate, which is compared with observed trends in O3 and NOx and the prevailing meteorology, and with the predictions of a detailed zero-dimensional atmospheric chemistry model

  17. Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

    DOEpatents

    Kansa, Edward J.; Wijesinghe, Ananda M.; Viani, Brian E.

    1997-01-01

    The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculents and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude.

  18. Nontoxic chemical process for in situ permeability enhancement and accelerated decontamination of fine-grain subsurface sediments

    DOEpatents

    Kansa, E.J.; Wijesinghe, A.M.; Viani, B.E.

    1997-01-14

    The remediation of heterogeneous subsurfaces is extremely time consuming and expensive with current and developing technologies. Although such technologies can adequately remove contaminants in the high hydraulic conductivity, coarse-grained sediments, they cannot access the contaminated low hydraulic conductivity fine-grained sediments. The slow bleed of contaminants from the fine-grained sediments is the primary reason why subsurface remediation is so time-consuming and expensive. This invention addresses the problem of remediating contaminated fine-grained sediments. It is intended that, in the future, a heterogeneous site be treated by a hybrid process that first remediates the high hydraulic conductivity, coarse-grained sediments, to be followed by the process, described in this invention, to treat the contaminated low hydraulic conductivity fine-grained sediments. The invention uses cationic flocculants and organic solvents to collapse the swelling negative double layer surrounding water saturated clay particles, causing a flocculated, cracked clay structure. The modification of the clay fabric in fine-grained sediments dramatically increases the hydraulic conductivity of previously very tight clays many orders of magnitude. 8 figs.

  19. Chemical characterization of fine particulate matter in Changzhou, China, and source apportionment with offline aerosol mass spectrometry

    NASA Astrophysics Data System (ADS)

    Ye, Zhaolian; Liu, Jiashu; Gu, Aijun; Feng, Feifei; Liu, Yuhai; Bi, Chenglu; Xu, Jianzhong; Li, Ling; Chen, Hui; Chen, Yanfang; Dai, Liang; Zhou, Quanfa; Ge, Xinlei

    2017-02-01

    Knowledge of aerosol chemistry in densely populated regions is critical for effective reduction of air pollution, while such studies have not been conducted in Changzhou, an important manufacturing base and populated city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particulate matter (PM2.5) samples, collected during July 2015 to April 2016 across four seasons in this city. A suite of analytical techniques was employed to measure the organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM2.5; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosol (WSOA). The average PM2.5 concentration was found to be 108.3 µg m-3, and all identified species were able to reconstruct ˜ 80 % of the PM2.5 mass. The WSIIs occupied about half of the PM2.5 mass (˜ 52.1 %), with SO42-, NO3-, and NH4+ as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating that traffic emissions were more important than stationary sources. OC and EC correlated well with each other and the highest OC / EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondary and primary ones. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to ˜ 5.0 % of PM2.5 during winter. PAH concentrations were also high in winter (140.25 ng m-3), which were predominated by median/high molecular weight PAHs with five and six rings. The organic matter including both water-soluble and water-insoluble species occupied ˜ 21.5 % of the PM2.5 mass. SP-AMS determined that the WSOA had average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), nitrogen-to-carbon (N / C), and organic

  20. Characterization and Prediction of Chemical Functions and Weight Fractions in Consumer Products

    EPA Science Inventory

    Assessing exposures from the thousands of chemicals in commerce requires quantitative information on the chemical constituents of consumer products. Unfortunately, gaps in available composition data prevent assessment of exposure to chemicals in many products. Here we propose fil...

  1. The chemical logic of plant natural product biosynthesis.

    PubMed

    Anarat-Cappillino, Gülbenk; Sattely, Elizabeth S

    2014-06-01

    Understanding the logic of plant natural product biosynthesis is important for three reasons: it guides the search for new natural products and pathways, illuminates the function of existing pathways in the context of host biology, and builds an enabling 'parts list' for plant and microbial metabolic engineering. In this review, we highlight the chemical themes that underlie a broad range of plant pathways, dividing pathways into two parts: scaffold-generating steps that draw on a limited set of chemistries, and tailoring reactions that produce a wide range of end products from a small number of common scaffolds.

  2. Cofactor engineering for more efficient production of chemicals and biofuels.

    PubMed

    Wang, Meng; Chen, Biqiang; Fang, Yunming; Tan, Tianwei

    2017-09-20

    Cofactors are involved in numerous intracellular reactions and critically influence redox balance and cellular metabolism. Cofactor engineering can support and promote the biocatalysis process, even help driving thermodynamically unfavorable reactions forwards. To achieve efficient production of chemicals and biofuels, cofactor engineering strategies such as altering cofactor supply or modifying reactants' cofactor preference have been developed to maintain redox balance. This review focuses primarily on the effects of cofactor engineering on carbon and energy metabolism. Coupling carbon metabolism with cofactor engineering can promote large-scale production, and even offer possibilities for producing new products or converting new materials. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Reduced product yield in chemical processes by second law effects

    NASA Technical Reports Server (NTRS)

    England, C.; Funk, J. E.

    1980-01-01

    An analysis of second law effects in chemical processes, where product yield is explicitly related to the individual irreversibilities within the process to indicate a maximum theoretical yield, is presented. Examples are given that indicate differences between first and second law approaches toward process efficiency and process yield. This analysis also expresses production capacity in terms of the heating value of a product. As a result, it is particularly convenient in analyzing fuel conversion plants and their potential for improvement. Relationships are also given for the effects of irreversibilities on requirements for process heat and for feedstocks.

  4. Defining the Product Chemical Space of Monoterpenoid Synthases

    PubMed Central

    Tian, Boxue; Poulter, C. Dale; Jacobson, Matthew P.

    2016-01-01

    Terpenoid synthases create diverse carbon skeletons by catalyzing complex carbocation rearrangements, making them particularly challenging for enzyme function prediction. To begin to address this challenge, we have developed a computational approach for the systematic enumeration of terpenoid carbocations. Application of this approach allows us to systematically define a nearly complete chemical space for the potential carbon skeletons of products from monoterpenoid synthases. Specifically, 18758 carbocations were generated, which we cluster into 74 cyclic skeletons. Five of the 74 skeletons are found in known natural products; some of the others are plausible for new functions, either in nature or engineered. This work systematizes the description of function for this class of enzymes, and provides a basis for predicting functions of uncharacterized enzymes. To our knowledge, this is the first computational study to explore the complete product chemical space of this important class of enzymes. PMID:27517297

  5. Replicated throughfall exclusion experiment in an Indonesian perhumid rainforest: wood production, litter fall and fine root growth under simulated drought.

    PubMed

    Moser, Gerald; Schuldt, Bernhard; Hertel, Dietrich; Horna, Viviana; Coners, Heinz; Barus, Henry; Leuschner, Christoph

    2014-05-01

    Climate change scenarios predict increases in the frequency and duration of ENSO-related droughts for parts of South-East Asia until the end of this century exposing the remaining rainforests to increasing drought risk. A pan-tropical review of recorded drought-related tree mortalities in more than 100 monitoring plots before, during and after drought events suggested a higher drought-vulnerability of trees in South-East Asian than in Amazonian forests. Here, we present the results of a replicated (n = 3 plots) throughfall exclusion experiment in a perhumid tropical rainforest in Sulawesi, Indonesia. In this first large-scale roof experiment outside semihumid eastern Amazonia, 60% of the throughfall was displaced during the first 8 months and 80% during the subsequent 17 months, exposing the forest to severe soil desiccation for about 17 months. In the experiment's second year, wood production decreased on average by 40% with largely different responses of the tree families (ranging from -100 to +100% change). Most sensitive were trees with high radial growth rates under moist conditions. In contrast, tree height was only a secondary factor and wood specific gravity had no influence on growth sensitivity. Fine root biomass was reduced by 35% after 25 months of soil desiccation while fine root necromass increased by 250% indicating elevated fine root mortality. Cumulative aboveground litter production was not significantly reduced in this period. The trees from this Indonesian perhumid rainforest revealed similar responses of wood and litter production and root dynamics as those in two semihumid Amazonian forests subjected to experimental drought. We conclude that trees from paleo- or neotropical forests growing in semihumid or perhumid climates may not differ systematically in their growth sensitivity and vitality under sublethal drought stress. Drought vulnerability may depend more on stem cambial activity in moist periods than on tree height or wood

  6. Transformation products in the life cycle impact assessment of chemicals.

    PubMed

    van Zelm, Rosalie; Huijbregts, Mark A J; van de Meent, Dik

    2010-02-01

    The current life cycle impact assessment (LCIA) of chemicals focuses only on the fate and effects of the parent compound, neglecting the potential impact of transformation products. Here, we assess the importance of including the potential impact of transformation products in the calculation of characterization factors (CF). The developed method is applied to freshwater ecotoxicity for 15 pesticides and perchloroethylene, which are all known to have potentially persistent transformation products. The inclusion of transformation products resulted in a median increase in CF that varied from negligible to more than 5 orders of magnitude. This increase, however, can be highly uncertain, particularly due to a lack of toxicity data for transformation products and a lack of mode of action-specific data. We show in a case study that replacement of atrazine with other pesticides for application on corn results in a median impact score of 2 orders of magnitude lower when the fate and effects of only the parent compounds are included. When transformation products are included, the reduction in median impact score would likely be lower (less than 1 order of magnitude). An uncertainty analysis showed that the difference in impact scores of atrazine and the atrazine replacements was not statistically significant when only the parent chemical was considered. When transformation products were included, the uncertainty in impact scores was even greater.

  7. New Vistas in Chemical Product and Process Design.

    PubMed

    Zhang, Lei; Babi, Deenesh K; Gani, Rafiqul

    2016-06-07

    Design of chemicals-based products is broadly classified into those that are process centered and those that are product centered. In this article, the designs of both classes of products are reviewed from a process systems point of view; developments related to the design of the chemical product, its corresponding process, and its integration are highlighted. Although significant advances have been made in the development of systematic model-based techniques for process design (also for optimization, operation, and control), much work is needed to reach the same level for product design. Timeline diagrams illustrating key contributions in product design, process design, and integrated product-process design are presented. The search for novel, innovative, and sustainable solutions must be matched by consideration of issues related to the multidisciplinary nature of problems, the lack of data needed for model development, solution strategies that incorporate multiscale options, and reliability versus predictive power. The need for an integrated model-experiment-based design approach is discussed together with benefits of employing a systematic computer-aided framework with built-in design templates.

  8. Super-fine rice-flour production by enzymatic treatment with high hydrostatic pressure processing

    NASA Astrophysics Data System (ADS)

    Kido, Miyuki; Kobayashi, Kaneto; Chino, Shuji; Nishiwaki, Toshikazu; Homma, Noriyuki; Hayashi, Mayumi; Yamamoto, Kazutaka; Shigematsu, Toru

    2013-06-01

    In response to the recent expansion of rice-flour use, we established a new rice-flour manufacturing process through the application of high hydrostatic pressure (HP) to the enzyme-treated milling method. HP improved both the activity of pectinase, which is used in the enzyme-treated milling method and the water absorption capacity of rice grains. These results indicate improved damage to the tissue structures of rice grains. In contrast, HP suppressed the increase in glucose, which may have led to less starch damage. The manufacturing process was optimized to HP treatment at 200 MPa (40°C) for 1 h and subsequent wet-pulverization at 11,000 rpm. Using this process, rice flour with an exclusively fine mean particle size less than 20 μm and starch damage less than 5% was obtained from rice grains soaked in an enzyme solution and distilled water. This super-fine rice flour is suitable for bread, pasta, noodles and Western-style sweets.

  9. Production of pyroxene ceramics from the fine fraction of incinerator bottom ash.

    PubMed

    Bourtsalas, A; Vandeperre, L J; Grimes, S M; Themelis, N; Cheeseman, C R

    2015-11-01

    Incinerator bottom ash (IBA) is normally processed to extract metals and the coarse mineral fraction is used as secondary aggregate. This leaves significant quantities of fine material, typically less than 4mm, that is problematic as reuse options are limited. This work demonstrates that fine IBA can be mixed with glass and transformed by milling, calcining, pressing and sintering into high density ceramics. The addition of glass aids liquid phase sintering, milling increases sintering reactivity and calcining reduces volatile loss during firing. Calcining also changes the crystalline phases present from quartz (SiO2), calcite (CaCO3), gehlenite (Ca2Al2SiO7) and hematite (Fe2O3) to diopside (CaMgSi2O6), clinoenstatite (MgSiO3) and andradite (Ca3Fe2Si3O12). Calcined powders fired at 1080°C have high green density, low shrinkage (<7%) and produce dense (2.78 g/cm(3)) ceramics that have negligible water absorption. The transformation of the problematic fraction of IBA into a raw material suitable for the manufacture of ceramic tiles for use in urban paving and other applications is demonstrated. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Fine root productivity varies along nitrogen and phosphorus gradients in high-rainfall mangrove forests of Micronesia

    USGS Publications Warehouse

    Cormier, Nicole; Twilley, Robert R.; Ewel, Katherine C.; Krauss, Ken W.

    2015-01-01

    Belowground biomass is thought to account for much of the total biomass in mangrove forests and may be related to soil fertility. The Yela River and the Sapwalap River, Federated States of Micronesia, contain a natural soil resource gradient defined by total phosphorus (P) density ranging from 0.05 to 0.42 mg cm−3 in different hydrogeomorphic settings. We used this fertility gradient to test the hypothesis that edaphic conditions constrain mangrove productivity through differential allocation of biomass to belowground roots. We removed sequential cores and implanted root ingrowth bags to measure in situ biomass and productivity, respectively. Belowground root biomass values ranged among sites from 0.448 ± 0.096 to 2.641 ± 0.534 kg m−2. Root productivity (roots ≤20 mm) did not vary significantly along the gradient (P = 0.3355) or with P fertilization after 6 months (P = 0.2968). Fine root productivity (roots ≤2 mm), however, did vary significantly among sites (P = 0.0363) and ranged from 45.88 ± 21.37 to 118.66 ± 38.05 g m−2 year−1. The distribution of total standing root biomass and fine root productivity followed patterns of N:P ratios as hypothesized, with larger root mass generally associated with lower relative P concentrations. Many of the processes of nutrient acquisition reported from nutrient-limited mangrove forests may also occur in forests of greater biomass and productivity when growing along soil nutrient gradients.

  11. Metabolic engineering of Escherichia coli: a sustainable industrial platform for bio-based chemical production.

    PubMed

    Chen, Xianzhong; Zhou, Li; Tian, Kangming; Kumar, Ashwani; Singh, Suren; Prior, Bernard A; Wang, Zhengxiang

    2013-12-01

    In order to decrease carbon emissions and negative environmental impacts of various pollutants, more bulk and/or fine chemicals are produced by bioprocesses, replacing the traditional energy and fossil based intensive route. The Gram-negative rod-shaped bacterium, Escherichia coli has been studied extensively on a fundamental and applied level and has become a predominant host microorganism for industrial applications. Furthermore, metabolic engineering of E. coli for the enhanced biochemical production has been significantly promoted by the integrated use of recent developments in systems biology, synthetic biology and evolutionary engineering. In this review, we focus on recent efforts devoted to the use of genetically engineered E. coli as a sustainable platform for the production of industrially important biochemicals such as biofuels, organic acids, amino acids, sugar alcohols and biopolymers. In addition, representative secondary metabolites produced by E. coli will be systematically discussed and the successful strategies for strain improvements will be highlighted. Moreover, this review presents guidelines for future developments in the bio-based chemical production using E. coli as an industrial platform.

  12. Chemical products induce resistance to Xanthomonas perforans in tomato

    PubMed Central

    Itako, Adriana Terumi; Tolentino, João Batista; da Silva, Tadeu Antônio Fernandes; Soman, José Marcelo; Maringoni, Antonio Carlos

    2015-01-01

    The bacterial spot of tomato, caused by Xanthomonas spp., is a very important disease, especially in the hot and humid periods of the year. The chemical control of the disease has not been very effective for a number of reasons. This study aimed to evaluate, under greenhouse conditions, the efficacy of leaf-spraying chemicals (acibenzolar-S-methyl (ASM) (0.025 g.L−1), fluazinam (0.25 g.L−1), pyraclostrobin (0.08 g.L−1), pyraclostrobin + methiran (0.02 g.L−1 + 2.2 g.L−1), copper oxychloride (1.50 g.L−1), mancozeb + copper oxychloride (0.88 g.L−1 + 0.60 g.L−1), and oxytetracycline (0.40 g.L−1)) on control of bacterial spot. Tomatoes Santa Clara and Gisele cultivars were pulverized 3 days before inoculation with Xanthomonas perforans. The production of enzymes associated with resistance induction (peroxidase, polyphenol oxidase, phenylalanine ammonia-lyase, β-1,3-glucanase, and protease) was quantified from leaf samples collected 24 hours before and 24 hours after chemical spraying and at 1, 2, 4, 6, and 8 days after bacterial inoculation. All products tested controlled bacterial spot, but only ASM, pyraclostrobin, and pyraclostrobin + metiram increased the production of peroxidase in the leaves of the two tomato cultivars, and increased the production of polyphenol oxidase and β-1,3-glucanase in the Santa Clara cultivar. PMID:26413050

  13. Comparing Chemical Mechanisms using Tagged Ozone Production Potentials

    NASA Astrophysics Data System (ADS)

    Coates, J.; Butler, T. M.

    2013-12-01

    Tropospheric ozone (O3) is a short-lived climate forcing pollutant that is detrimental to human health and crop growth. It is produced by reactions of volatile organic compounds (VOCs) and nitrogen oxides (NOx) in the presence of sunlight [Atkinson,2000]. The chemistry of intermediate species formed during VOC degradation show a time dependence and impacts the amount of O3 produced by the VOC [Butler et al., 2011]. Representing the intricacies of these reactions is not viable for chemical mechanisms used in global and regional models due to the computational resources available. Thus, chemical mechanisms reduce the amount of reactions either by lumping chemical species together as a model species, reducing the number of reaction pathways or both. As different chemical mechanisms use varying reduction techniques and assumptions especially with respect to the intermediate degradation species, it is important to compare the temporal evolution of ozone production obtained from differing chemical mechanisms. In this study, chemical mechanisms are compared using Tagged Ozone Production Potentials (TOPP) [Butler et al.,2011]. TOPPs measure the effect of a VOC on the odd oxygen family (Ox), which includes O3, nitrogen dioxide (NO2) and other species whose cycling effect O3 and NO2 production. TOPP values are obtained via a boxmodel run lasting seven diurnal cycles and tagging all species produced during VOC degradation; this enables the Ox production to be attributed to the VOC. This technique enables the temporal evolution of a VOCs' Ox production to be compared between the mechanisms. Comparing the TOPP profiles of the VOCs obtained using different mechanisms shows the effect of reduction techniques implemented by the mechanism and also allows a comparison of the tropospheric chemistry represented in the mechanisms. [Atkinson,2000] Atkinson, R. (2000). Atmospheric chemistry of VOCs and NOx. Atmospheric Environment, 34:2063-2101 [Butler et al., 2011] Butler, T. M

  14. DEVELOPMENT AND EVALUATION OF A HIGH-VOLUME DICHOTOMOUS SAMPLER FOR CHEMICAL SPECIATION OF COARSE AND FINE PARTICLES

    EPA Science Inventory

    This paper describes the development and field evaluation of a compact high-volume dichotomous sampler (HVDS) that collects coarse (PM10-2.5) and fine (PM2.5) particulate matter. In its primary configuration as tested, the sampler size-fractionates PM10 into...

  15. DEVELOPMENT AND EVALUATION OF A HIGH-VOLUME DICHOTOMOUS SAMPLER FOR CHEMICAL SPECIATION OF COARSE AND FINE PARTICLES

    EPA Science Inventory

    This paper describes the development and field evaluation of a compact high-volume dichotomous sampler (HVDS) that collects coarse (PM10-2.5) and fine (PM2.5) particulate matter. In its primary configuration as tested, the sampler size-fractionates PM10 into...

  16. Green light: gross primary production influences seasonal stream N export by controlling fine-scale N dynamics.

    PubMed

    Lupon, Anna; Martí, Eugènia; Sabater, Francesc; Bernal, Susana

    2016-01-01

    Monitoring nutrient concentrations at fine-scale temporal resolution contributes to a better understanding of nutrient cycling in stream ecosystems. However, the mechanisms underlying fine-scale nutrient dynamics and its implications for budget catchent fluxes are still poorly understood. To gain understanding of patterns and controls of fine-scale stream nitrogen (N) dynamics and to assess how they affect hydrological N fluxes, we explored diel variation in stream nitrate (NO3-) concentration along a headwater stream with increasing riparian area and channel width. At the downstream site, the highest day-night variations occurred in early spring, when stream NO3- concentrations were 13% higher at night than at daytime. Such day-night variations were strongly related to daily light inputs (R2 = 0.74) and gross primary production (GPP; R2 = 0.74), and they showed an excellent fit with day-night NO- variations predicted from GPP (R2 = 0.85). These results suggest that diel fluctuations in stream NO3- concentration were mainly driven by photoautotrophic N uptake. Terrestrial influences were discarded because no simultaneous diel variations in stream discharge, riparian groundwater level, or riparian solute concentration were observed. In contrast to the downstream site, no diel variations in NO3- concentration occurred at the upstream site, likely because water temperature was colder (10 degrees C vs. 12 degrees C) and light availability was lower (4 vs. 9 mol x m(-2) x d(-1)). Although daily GPP was between 10- and 100-fold lower than daily respiration, photoautotrophic N uptake contributed to a 10% reduction in spring NO3- loads at the downstream site. Our study clearly shows that the activity of photoautotrophs can substantially change over time and along the stream continuum in response to key environmental drivers such as light and temperature, and further, that its capacity to regulate diel and seasonal N fluxes can be important even in low-productivity streams.

  17. Elevated atmospheric CO2 stimulates soil fungal diversity through increased fine root production in a semiarid shrubland ecosystem.

    PubMed

    Lipson, David A; Kuske, Cheryl R; Gallegos-Graves, La Verne; Oechel, Walter C

    2014-08-01

    Soil fungal communities are likely to be central in mediating microbial feedbacks to climate change through their effects on soil carbon (C) storage, nutrient cycling, and plant health. Plants often produce increased fine root biomass in response to elevated atmospheric carbon dioxide (CO2 ), but the responses of soil microbial communities are variable and uncertain, particularly in terms of species diversity. In this study, we describe the responses of the soil fungal community to free air CO2 enrichment (FACE) in a semiarid chaparral shrubland in Southern California (dominated by Adenomstoma fasciculatum) using large subunit rRNA gene sequencing. Community composition varied greatly over the landscape and responses to FACE were subtle, involving a few specific groups. Increased frequency of Sordariomycetes and Leotiomycetes, the latter including the Helotiales, a group that includes many dark septate endophytes known to associate positively with roots, was observed in the FACE plots. Fungal diversity, both in terms of richness and evenness, increased consistently in the FACE treatment, and was relatively high compared to other studies that used similar methods. Increases in diversity were observed across multiple phylogenetic levels, from genus to class, and were distributed broadly across fungal lineages. Diversity was also higher in samples collected close to (5 cm) plants compared to samples in canopy gaps (30 cm away from plants). Fungal biomass correlated well with soil organic matter (SOM) content, but patterns of diversity were correlated with fine root production rather than SOM. We conclude that the fungal community in this ecosystem is tightly linked to plant fine root production, and that future changes in the fungal community in response to elevated CO2 and other climatic changes will be primarily driven by changes in plant belowground allocation. Potential feedbacks mediated by soil fungi, such as soil C sequestration, nutrient cycling, and

  18. Organo- and nano-catalyst in greener reaction medium: Microwave-assisted expedient synthesis of fine chemicals

    EPA Science Inventory

    The use of emerging microwave (MW) -assisted chemistry techniques is dramatically reducing chemical waste and reaction times in several organic syntheses and chemical transformations. A brief account of our experiences in developing MW-assisted organic transformations, which invo...

  19. Artificial photosynthesis for sustainable fuel and chemical production.

    PubMed

    Kim, Dohyung; Sakimoto, Kelsey K; Hong, Dachao; Yang, Peidong

    2015-03-09

    The apparent incongruity between the increasing consumption of fuels and chemicals and the finite amount of resources has led us to seek means to maintain the sustainability of our society. Artificial photosynthesis, which utilizes sunlight to create high-value chemicals from abundant resources, is considered as the most promising and viable method. This Minireview describes the progress and challenges in the field of artificial photosynthesis in terms of its key components: developments in photoelectrochemical water splitting and recent progress in electrochemical CO2 reduction. Advances in catalysis, concerning the use of renewable hydrogen as a feedstock for major chemical production, are outlined to shed light on the ultimate role of artificial photosynthesis in achieving sustainable chemistry. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Chemicals from biomass: an assessment of the potential for production of chemical feedstocks from renewable resources

    SciTech Connect

    Donaldson, T.L.; Culberson, O.L.

    1983-06-01

    This assessment of the potential for production of commodity chemicals from renewable biomass resources is based on (1) a Delphi study with 50 recognized authorities to identify key technical issues relevant to production of chemicals from biomass, and (2) a systems model based on linear programming for a commodity chemicals industry using renewable resources and coal as well as gas and petroleum-derived resources. Results from both parts of the assessment indicate that, in the absence of gas and petroleum, coal undoubtedly would be a major source of chemicals first, followed by biomass. The most attractive biomass resources are wood, agricultural residues, and sugar and starch crops. A reasonable approximation to the current product slate for the petrochemical industry could be manufactured using only renewable resources for feedstocks. Approximately 2.5 quads (10/sup 15/ Btu (1.055 x 10/sup 18/ joules)) per year of oil and gas would be released. Further use of biomass fuels in the industry could release up to an additional 1.5 quads. however, such an industry would be unprofitable under current economic conditions with existing or near-commercial technology. As fossil resources become more expensive and biotechnology becomes more efficient, the economics will be more favorable. Use of the chemicals industry model to evaluate process technologies is demonstrated. Processes are identified which have potential for significant added value to the system if process improvements can be made to improve the economics. Guidelines and recommendations for research and development programs to improve the attractiveness of chemicals from biomass are discussed.

  1. 75 FR 33824 - Pharmaceutical Products and Chemical Intermediates, Fourth Review: Advice Concerning the Addition...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-15

    ... COMMISSION Pharmaceutical Products and Chemical Intermediates, Fourth Review: Advice Concerning the Addition of Certain Products to the Pharmaceutical Appendix to the HTS AGENCY: United States International... (Commission) instituted investigation No. 332-520, Pharmaceutical Products and Chemical Intermediates, Fourth...

  2. Production of fine structures in type III solar radio bursts due to turbulent density profiles

    SciTech Connect

    Loi, Shyeh Tjing; Cairns, Iver H.; Li, Bo

    2014-07-20

    Magnetic reconnection events in the corona release energetic electron beams along open field lines, and the beams generate radio emission at multiples of the electron plasma frequency f{sub p} to produce type III solar radio bursts. Type III bursts often exhibit irregularities in the form of flux modulations with frequency and/or local temporal advances and delays, and a type IIIb burst represents the extreme case where a type III burst is fragmented into a chain of narrowband features called striae. Remote and in situ spacecraft measurements have shown that density turbulence is ubiquitous in the corona and solar wind, and often exhibits a Kolmogorov power spectrum. In this work, we numerically investigate the effects of one-dimensional macroscopic density turbulence (along the beam direction) on the behavior of type III bursts, and find that this turbulence produces stria-like fine structures in the dynamic spectra of both f{sub p} and 2 f{sub p} radiation. Spectral and temporal fine structures in the predicted type III emission are produced by variations in the scattering path lengths and group speeds of radio emission, and in the locations and sizes of emitting volumes. Moderate turbulence levels yield flux enhancements with much broader half-power bandwidths in f{sub p} than 2 f{sub p} emission, possibly explaining the often observed type IIIb-III harmonic pairs as being where intensifications in 2 f{sub p} radiation are not resolved observationally. Larger turbulence levels producing trough-peak regions in the plasma density profile may lead to broader, resolvable intensifications in 2 f{sub p} radiation, which may account for the type IIIb-IIIb pairs that are sometimes observed.

  3. Effects of aspirin on distortion product fine structure: interpreted by the two-source model for distortion product otoacoustic emissions generation.

    PubMed

    Rao, Aparna; Long, Glenis R

    2011-02-01

    Distortion product otoacoustic emission (DPOAE) fine structure is due to the interaction of two major components coming from different places in the cochlea. One component is generated from the region of maximal overlap of the traveling waves generated by the two primaries and is attributed to nonlinear distortion (nonlinear component). The other component arises predominantly from the tonotopic region of the distortion product and is attributed to linear coherent reflection (reflection component). Aspirin (salicylate) ototoxicity can cause reversible hearing loss and reduces otoacoustic emission generation in the cochlea. The two components are expected to be affected differentially by cochlear health. Changes in DPOAE fine structure were recorded longitudinally in three subjects before, during, and after aspirin consumption. Full data sets were analyzed for two subjects, but only partial data could be analyzed from the third subject. Resulting changes in the two components of DPOAE fine structure revealed variability among subjects and differential effects on the two components. For low-intensity primaries, both components were reduced with the reflection component being more vulnerable. For high-intensity primaries, the nonlinear component showed little or no change, but the reflection component was always reduced.

  4. Chemical Conversion of Energetic Materials to Higher Value Products

    SciTech Connect

    Mitchell, A R; Hsu, P C; Coburn, M D; Schmidt, R D; Pagoria, P F; Lee, G S

    2005-04-19

    The objective of this program is to develop new processes for the disposal of surplus energetic materials. Disposal through open burning/open detonation (OB/OD) is considered less attractive today due to environmental, cost and safety concerns. The use of energetic materials as chemical feedstocks for higher value products can provide environmentally sound and cost-effective alternatives to OB/OD. Our recent studies on the conversion of surplus energetic materials (Explosive D, TNT) to higher value products will be described.

  5. Exploring consumer exposure pathways and patterns of use for chemicals in the environment through the Chemical/Product Categories Database

    EPA Pesticide Factsheets

    Exploring consumer exposure pathways and patterns of use for chemicals in the environment through the Chemical/Product Categories Database (CPCat) (Presented by: Kathie Dionisio, Sc.D., NERL, US EPA, Research Triangle Park, NC (1/23/2014).

  6. Multi-scale modeling for sustainable chemical production.

    PubMed

    Zhuang, Kai; Bakshi, Bhavik R; Herrgård, Markus J

    2013-09-01

    With recent advances in metabolic engineering, it is now technically possible to produce a wide portfolio of existing petrochemical products from biomass feedstock. In recent years, a number of modeling approaches have been developed to support the engineering and decision-making processes associated with the development and implementation of a sustainable biochemical industry. The temporal and spatial scales of modeling approaches for sustainable chemical production vary greatly, ranging from metabolic models that aid the design of fermentative microbial strains to material and monetary flow models that explore the ecological impacts of all economic activities. Research efforts that attempt to connect the models at different scales have been limited. Here, we review a number of existing modeling approaches and their applications at the scales of metabolism, bioreactor, overall process, chemical industry, economy, and ecosystem. In addition, we propose a multi-scale approach for integrating the existing models into a cohesive framework. The major benefit of this proposed framework is that the design and decision-making at each scale can be informed, guided, and constrained by simulations and predictions at every other scale. In addition, the development of this multi-scale framework would promote cohesive collaborations across multiple traditionally disconnected modeling disciplines to achieve sustainable chemical production.

  7. Update on the Chemical Composition Of Crystalline, Smectite, and Amorphous Components for Rocknest Soil and John Klein and Cumberland Mudstone Drill Fines at Gale Crater, Mars

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Ming, D. W.; Gellert, R.; Vaniman, D. T.; Bish, D. L.; Blake, D. F.; Chipera, S. J.; Morrison, S. M.; Downs, R. T.; Rampe, E. B.; Treiman, A. H.; Yen, A. S.; Achilles, C. N.; Archer, P. D.; Bristow, T. F.; Cavanaugh, P.; Fenrdrich, K.; Crisp, J. A.; Des Marais, D. J.; Farmer, J. D.; Grotzinger, J. P.; Mahaffy, P. R.; McAdam, A. C.; Morookian, J. M.

    2015-01-01

    We have previously calculated the chemical compositions of the X-ray-diffraction (XRD) amorphous component of three solid samples (Rocknest (RN) soil, John Klein (JK) drill fines, and Cumberland (CB) drill fines) using major-element chemistry (APXS), volatile-element chemistry (SAM), and crystalline- phase mineralogy (CheMin) obtained by the Curiosity rover as a part of the ongoing Mars Science Laboratory mission in Gale Crater. According to CheMin analysis, the RN and the JK and CB samples are mineralogically distinct in that RN has no detectable clay minerals and both JK and CB have significant concentrations of high-Fe saponite. The chemical composition of the XRD amorphous component is the composition remaining after mathematical removal of the compositions of crystalline components, including phyllosilicates if present. Subsequent to, we have improved the unit cell parameters for Fe-forsterite, augite, and pigeonite, resulting in revised chemical compositions for the XRD-derived crystalline component (excluding clay minerals). We update here the calculated compositions of amorphous components using these revised mineral compositions.

  8. Compositions of coarse and fine particles in martian soils at gale: A window into the production of soils

    NASA Astrophysics Data System (ADS)

    Cousin, A.; Meslin, P. Y.; Wiens, R. C.; Rapin, W.; Mangold, N.; Fabre, C.; Gasnault, O.; Forni, O.; Tokar, R.; Ollila, A.; Schröder, S.; Lasue, J.; Maurice, S.; Sautter, V.; Newsom, H.; Vaniman, D.; Le Mouélic, S.; Dyar, D.; Berger, G.; Blaney, D.; Nachon, M.; Dromart, G.; Lanza, N.; Clark, B.; Clegg, S.; Goetz, W.; Berger, J.; Barraclough, B.; Delapp, D.

    2015-03-01

    The ChemCam instrument onboard the Curiosity rover provides for the first time an opportunity to study martian soils at a sub-millimeter resolution. In this work, we analyzed 24 soil targets probed by ChemCam during the first 250 sols on Mars. Using the depth profile capability of the ChemCam LIBS (Laser-Induced Breakdown Spectroscopy) technique, we found that 45% of the soils contained coarse grains (>500 μm). Three distinct clusters have been detected: Cluster 1 shows a low SiO2 content; Cluster 2 corresponds to coarse grains with a felsic composition, whereas Cluster 3 presents a typical basaltic composition. Coarse grains from Cluster 2 have been mostly observed exposed in the vicinity of the landing site, whereas coarse grains from Clusters 1 and 3 have been detected mostly buried, and were found all along the rover traverse. The possible origin of these coarse grains was investigated. Felsic (Cluster 2) coarse grains have the same origin as the felsic rocks encountered near the landing site, whereas the origin of the coarse grains from Clusters 1 and 3 seems to be more global. Fine-grained soils (particle size < laser beam diameter which is between 300 and 500 μm) show a homogeneous composition all along the traverse, different from the composition of the rocks encountered at Gale. Although they contain a certain amount of hydrated amorphous component depleted in SiO2, possibly present as a surface coating, their overall chemical homogeneity and their close-to-basaltic composition suggest limited, or isochemical alteration, and a limited interaction with liquid water. Fine particles and coarse grains from Cluster 1 have a similar composition, and the former could derive from weathering of the latter. Overall martian soils have a bulk composition between that of fine particles and coarse grains. This work shows that the ChemCam instrument provides a means to study the variability of soil composition at a scale not achievable by bulk chemical analyses.

  9. Forest fine-root production and nitrogen use under elevated CO2: Contrasting responses explained by a common principle

    SciTech Connect

    Franklin, Oscar; McMurtrie, Ross E; Iversen, Colleen M; Crous, Kristine; Finzi, Adrien C; Tissue, David Thomas; Ellsworth, David; Oren, Ram; Norby, Richard J

    2009-01-01

    Despite the importance of nitrogen (N) limitation of forest carbon (C) sequestration at rising atmospheric CO2 concentration, the mechanisms responsible are not well understood. To elucidate the interactive effects of elevated CO2 (eCO2) and soil N availability on forest productivity and C allocation, we hypothesized that 1) trees maximize fitness by allocating N and C to maximize their net growth, and 2) that N uptake is controlled by root exploration for N. We tested this model using data collected in FACE sites dominated by evergreen (Pinus taeda; Duke Forest) and deciduous (Liquidambar styraciflua; Oak Ridge National Laboratory ORNL) trees. The model explained 80-95% of variation in productivity and N-uptake data among eCO2, N fertilization and control treatments over six years. The model explains why fine-root production increased, and why N uptake increased despite reduced soil N availability under eCO2 at ORNL and Duke. In agreement with observations at other sites, soil N availability reduced below a critical level diminishes all eCO2 responses. At Duke, a negative feedback between reduced soil N availability and N uptake counteracted progressive reduction in soil N availability at eCO2. At ORNL, decreasing soil N availability was perpetuated as it generated no reduction in N uptake, due to strongly increased production of fast turnover fine-roots. This implies that species with fast root turnover could be more prone to progressive N limitation of carbon sequestration in woody biomass than species with slow root turnover, such as evergreens.

  10. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae.

    PubMed

    Li, Mingji; Borodina, Irina

    2015-02-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae We describe computational tools for the prediction of biochemical pathways, molecular biology methods for assembly of DNA parts into pathways, and for introducing the pathways into the host, and finally approaches for optimizing performance of the introduced pathways.

  11. Hazard Classification of Household Chemical Products in Korea according to the Globally Harmonized System of Classification and labeling of Chemicals

    PubMed Central

    2013-01-01

    Objectives This study was conducted to review the validity of the need for the application of the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) to household chemical products in Korea. The study also aimed to assess the severity of health and environmental hazards of household chemical products using the GHS. Methods 135 products were classified as ‘cleaning agents and polishing agents’ and 98 products were classified as ‘bleaches, disinfectants, and germicides.’ The current status of carcinogenic classification of GHS and carcinogenicity was examined for 272 chemical substances contained in household chemical products by selecting the top 11 products for each of the product categories. In addition, the degree of toxicity was assessed through analysis of whether the standard of the Republic of Korea’s regulations on household chemical products had been exceeded or not. Results According to GHS health and environmental hazards, “acute toxicity (oral)” was found to be the highest for two product groups, ‘cleaning agents and polishing agents’, and ‘bleaches, disinfectants, and germicides’ (result of classification of 233 household chemical products) at 37.8% and 52.0% respectively. In an analysis of carcinogenicity assuming a threshold of IARC 2B for the substances in household chemical products, we found ‘cleaning agents and polishing agents’ to contain 12 chemical substances and ‘bleaches, disinfectants, and germicides’ 11 chemical substances. Conclusion Some of the household chemical products were found to have a high hazard level including acute toxicity and germ cell mutagenicity, carcinogenicity, and reproductive toxicity. Establishing a hazard information delivery system including the application of GHS to household chemical products in Korea is urgent as well. PMID:24472347

  12. Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM2.5) Fraction of Coal Combustion Ash

    SciTech Connect

    T. L. Robl; J. G. Groppo; R. Rathbone; B. Marrs; R. Jewell

    2008-07-18

    The overall objective of this research was to determine the feasibility of recovering a very fine fraction of fly ash, that is 5 microns in diameter or less and examining the characteristics of these materials in new or at least less traditional applications. These applications included as a polymer filler or as a 'super' pozzolanic concrete additive. As part of the effort the ash from 6 power plants was investigated and characterized. This work included collection from ESP Hoppers and ponds. The ash was thoroughly characterized chemically and physically. Froth flotation was used to reduce the carbon and testing showed that flotation could effectively reduce carbon to acceptable levels (i.e. 0.5% LOI) for most of the substrates tested. in order to enable eventual use as fillers. Hydraulic classification was used in the separation of the fine ash from the coarse ash. Hydraulic classification requires the ash to be dispersed to be effective and a range of dispersants were tested for adsorption as well as sedimentation rate. A wide range of dosages were required (0.3 to 10 g/kg). In general the ponded ash required less dispersant. A model was developed for hydraulic classification. A pilot-scale hydraulic classifier was also designed and operated for the project. Product yields of up to 21% of feed solids were achieved with recoveries of <5 {micro}m particles as high as 64%. Mean particle sizes (D{sub 50}) of the ultra fine ash (UFA) products varied from 3.7 to 10 {micro}m. A patent was filed on the classifier design. A conceptual design of a Process Demonstration Unit (PDU) with a feed rate of 2 tons of raw ash feed per hour was also completed. Pozzolanic activity was determined for the UFA ashes in mortars. In general the overall strength index was excellent with values of 90% achieved in 3 days and {approx}100% in 7 days. Three types of thermoplastic polymers were evaluated with the UFA as a filler: high density polyethylene, thermoplastic elastomer and

  13. Source areas and chemical composition of fine particulate matter in the Pearl River Delta region of China

    NASA Astrophysics Data System (ADS)

    Hagler, G. S. W.; Bergin, M. H.; Salmon, L. G.; Yu, J. Z.; Wan, E. C. H.; Zheng, M.; Zeng, L. M.; Kiang, C. S.; Zhang, Y. H.; Lau, A. K. H.; Schauer, J. J.

    Fine particulate matter (PM 2.5) was measured for 4 months during 2002-2003 at seven sites located in the rapidly developing Pearl River Delta region of China, an area encompassing the major cities of Hong Kong, Shenzhen and Guangzhou. The 4-month average fine particulate matter concentration ranged from 37 to 71 μg m -3 in Guangdong province and from 29 to 34 μg m -3 in Hong Kong. Main constituents of fine particulate mass were organic compounds (24-35% by mass) and sulfate (21-32%). With sampling sites strategically located to monitor the regional air shed patterns and urban areas, specific source-related fine particulate species (sulfate, organic mass, elemental carbon, potassium and lead) and daily surface winds were analyzed to estimate influential source locations. The impact of transport was investigated by categorizing 13 (of 20 total) sampling days by prevailing wind direction (southerly, northerly or low wind-speed mixed flow). The vicinity of Guangzhou is determined to be a major source area influencing regional concentrations of PM 2.5, with levels observed to increase by 18-34 μg m -3 (accounting for 46-56% of resulting particulate levels) at sites immediately downwind of Guangzhou. The area near Guangzhou is also observed to heavily impact downwind concentrations of lead. Potassium levels, related to biomass burning, appear to be controlled by sources in the northern part of the Pearl River Delta, near rural Conghua and urban Guangzhou. Guangzhou appears to contribute 5-6 μg m -3 of sulfate to downwind locations. Guangzhou also stands out as a significant regional source of organic mass (OM), adding 8.5-14.5 μg m -3 to downwind concentrations. Elemental carbon is observed to be strongly influenced by local sources, with highest levels found in urban regions. In addition, it appears that sources outside of the Pearl River Delta contribute a significant fraction of overall fine particulate matter in Hong Kong and Guangdong province. This is evident

  14. Fine grain separation for the production of biomass fuel from mixed municipal solid waste.

    PubMed

    Giani, H; Borchers, B; Kaufeld, S; Feil, A; Pretz, T

    2016-01-01

    The main goal of the project MARSS (Material Advanced Sustainable Systems) is to build a demonstration plant in order to recover a renewable biomass fuel suitable for the use in biomass power plants out of mixed municipal solid waste (MMSW). The demonstration plant was constructed in Mertesdorf (Germany), working alongside an existing mechanical-biological treatment plant, where the MMSW is biological dried under aerobe conditions in rotting boxes. The focus of the presented sorting campaign was set on the processing of fine grain particles minor than 11.5mm which have the highest mass content and biogenic energy potential of the utilized grain size fractions. The objective was to produce a biomass fuel with a high calorific value and a low content of fossil (plastic, synthetic) materials while maximizing the mass recovery. Therefore, the biogenic components of the dried MMSW are separated from inert and fossil components through various classification and sifting processes. In three experimental process setups of different processing depths, the grain size fraction 4-11.5mm was sifted by the use of air sifters and air tables. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Prediction of product distribution in fine biomass pyrolysis in fluidized beds based on proximate analysis.

    PubMed

    Kim, Sung Won

    2015-01-01

    A predictive model was satisfactorily developed to describe the general trends of product distribution in fluidized beds of lignocellulosic biomass pyrolysis. The model was made of mass balance based on proximate analysis and an empirical relationship with operating parameters including fluidization hydrodynamics. The empirical relationships between product yields and fluidization conditions in fluidized bed pyrolyzers were derived from the data of this study and literature. The gas and char yields showed strong functions of temperature and vapor residence time in the pyrolyzer. The yields showed a good correlation with fluidization variables related with hydrodynamics and bed mixing. The predicted product yields based on the model well accorded well with the experimental data.

  16. Nanochemistry-derived Bi2WO6 nanostructures: towards production of sustainable chemicals and fuels induced by visible light.

    PubMed

    Zhang, Nan; Ciriminna, Rosaria; Pagliaro, Mario; Xu, Yi-Jun

    2014-08-07

    Low cost and easily made bismuth tungstate (Bi2WO6) could be one of the key technologies to make chemicals and fuels from biomass, atmospheric carbon dioxide and water at low cost using solar radiation as an energy source. Its narrow band gap (2.8 eV) enables ideal visible light (λ > 400 nm) absorption. Yet, it is the material's shape, namely the superstructure morphology wisely created via a nanochemistry approach, which leads to better electron-hole separation and much higher photoactivity. Recent results coupled to the versatile photochemistry of this readily available semiconductor suggest that the practical application of nanochemistry-derived Bi2WO6 nanostructures for the synthesis of value-added fine chemicals and fuel production is possible. We describe progress in this important field of chemical research from a nanochemistry viewpoint, and identify opportunities for further progress.

  17. Production of fuels and chemicals from apple pomace

    SciTech Connect

    Hang, Y.D.

    1987-03-01

    Nearly 36 million tons of apples are produced annually in the US. Approximately 45% of the total US apple production is used for processing purposes. The primary by-product of apple processing is apple pomace. It consists of the presscake resulting from pressing apples for juice or cider, including the presscake obtained in pressing peel and core wastes generated in the manufacture of apple sauce or slices. More than 500 food processing plants in the US produce a total of about 1.3 million metric tons of apple pomace each year, and it is likely that annual disposal fees exceed $10 million. Apple pomace has the potential to be used for the production of fuels (ethanol and biogas containing 60% methane) and food-grade chemicals. These uses will be reviewed in this article.

  18. Utilization of Horizontal Belt Filters for Washing Fine Alumina Seed and Kiln Feed Product

    NASA Astrophysics Data System (ADS)

    Crawford, Richard F.; Dahlstrom, Donald A.; Minear, Gerry

    In the processing of bauxite to produce alumina (Al2O3) for ultimate production of aluminum by electrolysis, the product must have a high purity and a closely controlled size distribution. As the entire alumina flowsheet involves fluids of high caustic concentration, one of the critical measures of product purity is the sodium content. This should be a maximum of 0.04 Wt% soluble Na2O. In the United States, smelters are based upon sandy alumina. Generally, sandy alumina trihydrate (Al2O3 × 3H2O) prior to calcining should have a size distribution in the range of 95% +44 microns and only a very small amount of -20 micron material to meet final alumina product size requirements.

  19. [Sustainable production of bulk chemicals by application of "white biotechnology"].

    PubMed

    Patel, M K; Dornburg, V; Hermann, B G; Shen, Li; van Overbeek, Leo

    2008-12-01

    Practically all organic chemicals and plastics are nowadays produced from crude oil and natural gas. However, it is possible to produce a wide range of bulk chemicals from renewable resources by application of biotechnology. This paper focuses on White Biotechnology, which makes use of bacteria (or yeasts) or enzymes for the conversion of the fermentable sugar to the target product. It is shown that White Biotechnology offers substantial savings of non-renewable energy use and greenhouse gas emissions for nearly all of the products studied. Under favorable boundary conditions up to two thirds (67%) of the current non-renewable energy use for the production of the selected chemicals can be saved by 2050 if substantial technological progress is made and if the use of lignocellulosic feedstocks is successfully developed. The analysis for Europe (E.U. 25 countries) shows that land requirements related to White Biotechnology chemicals are not likely to become a critical issue in the next few decades, especially considering the large unused and underutilized resources in Eastern Europe. Substantial macroeconomic savings can be achieved under favourable boundary conditions. In principle, natural bacteria and enzymes can be used for White Biotechnology but, according to many experts in the fields, Genetically Modified Organisms (GMO) will be necessary in order to achieve the high yields, concentrations and productivities that are required to reach economic viability. Safe containment and inactivation of GMOs after release is very important because not all possible implications caused by the interaction of recombinant genes with other populations can be foreseen. If adequate precautionary measures are taken, the risks related to the use of genetically modified organisms in White Biotechnology are manageable. We conclude that the core requirements to be fulfilled in order to make clear steps towards a bio-based chemical industry are substantial technological progress in the

  20. Impact Melting of Ordinary Chondrite Regoliths and the Production of Fine-grained Fe(sup 0)

    NASA Technical Reports Server (NTRS)

    Hoerz, Friedrich; Cintala, Mark J.; See, Thomas H.

    2003-01-01

    The detailed study of individual lunar soil grains provides evidence that the major optical properties of the lunar surface are primarily related to the production of fine-grained (< 20 nm, super-paramagnetic) Fe-particles in agglutinitic impact melts and to iron-rich vapor deposits on the surfaces of individual grains. These Fe-rich materials are derived from oxidized species due to high post-shock temperatures in the presence of solar-wind derived H2; part of the Fe-rich grain surfaces may also be due to sputtering processes. Identical processes were recently suggested for the optical maturation of S-type asteroid surfaces, the parent objects of ordinary chondrites (OCs). OCs, however, do not contain impact-produced soil melts, and should thus also be devoid of impact-triggered vapor condensates. The seeming disparity can only be understood if all OCs resemble relatively immature impact debris, akin to numerous lunar highland breccias. It is possible to assess this scenario by evaluating experimentally whether impact velocities of 5- 6 km/s, typical for the present day asteroid belt, suffice to produce both impact melts and fine-grained metallic iron. We used 125-250 m powders of the L6 chondrite ALH85017. These powders were aliquots from fines that were produced by collisionally disrupting a single, large (461g) chunk of this meteorite during nine impacts and by subjecting the resulting rubble to an additional 50 impacts. As a consequence, the present shock-recovery experiments employ target materials of exceptional fidelity (i.e., a real chondrite that was impact pulverized). The target powders were packed into tungsten-alloy containers to allow for the potential investigation of freshly produced, fine-grained iron and impacted by stainless-steel and tungsten flyer plates; the packing density varied between 38 and 45% porosity. Peak pressures ranged from 14.5 to 67 GPa and were attained after multiple reverberations of the shock wave at the interface of the

  1. Pathway engineering for the production of heterologous aromatic chemicals and their derivatives in Saccharomyces cerevisiae: bioconversion from glucose.

    PubMed

    Gottardi, Manuela; Reifenrath, Mara; Boles, Eckhard; Tripp, Joanna

    2017-06-01

    Saccharomyces cerevisiae has been extensively engineered for optimising its performance as a microbial cell factory to produce valuable aromatic compounds and their derivatives as bulk and fine chemicals. The production of heterologous aromatic molecules in yeast is achieved via engineering of the aromatic amino acid biosynthetic pathway. This pathway is connected to two pathways of the central carbon metabolism, and is highly regulated at the gene and protein level. These characteristics impose several challenges for tailoring it, and various modifications need to be applied in order to redirect the carbon flux towards the production of the desired compounds. This minireview addresses the metabolic engineering approaches targeting the central carbon metabolism, the shikimate pathway and the tyrosine and phenylalanine biosynthetic pathway of S. cerevisiae for biosynthesis of aromatic chemicals and their derivatives from glucose. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Biomedically relevant chemical and physical properties of coal combustion products.

    PubMed Central

    Fisher, G L

    1983-01-01

    The evaluation of the potential public and occupational health hazards of developing and existing combustion processes requires a detailed understanding of the physical and chemical properties of effluents available for human and environmental exposures. These processes produce complex mixtures of gases and aerosols which may interact synergistically or antagonistically with biological systems. Because of the physicochemical complexity of the effluents, the biomedically relevant properties of these materials must be carefully assessed. Subsequent to release from combustion sources, environmental interactions further complicate assessment of the toxicity of combustion products. This report provides an overview of the biomedically relevant physical and chemical properties of coal fly ash. Coal fly ash is presented as a model complex mixture for health and safety evaluation of combustion processes. PMID:6337824

  3. Inter-comparison of Seasonal Variation, Chemical Characteristics, and Source Identification of Atmospheric Fine Particles on Both Sides of the Taiwan Strait

    PubMed Central

    Li, Tsung-Chang; Yuan, Chung-Shin; Huang, Hu-Ching; Lee, Chon-Lin; Wu, Shui-Ping; Tong, Chuan

    2016-01-01

    The spatiotemporal distribution and chemical composition of atmospheric fine particles in areas around the Taiwan Strait were firstly investigated. Fine particles (PM2.5) were simultaneously collected at two sites on the west-side, one site at an offshore island, and three sites on the east-side of the Taiwan Strait in 2013–2014. Field sampling results indicated that the average PM2.5 concentrations at the west-side sampling sites were generally higher than those at the east-side sampling sites. In terms of chemical composition, the most abundant water-soluble ionic species of PM2.5 were SO42−, NO3−, and NH4+, while natural crustal elements dominated the metallic content of PM2.5, and the most abundant anthropogenic metals of PM2.5 were Pb, Ni and Zn. Moreover, high OC/EC ratios of PM2.5 were commonly observed at the west-side sampling sites, which are located at the downwind of major stationary sources. Results from CMB receptor modeling showed that the major sources of PM2.5 were anthropogenic sources and secondary aerosols at the both sides, and natural sources dominated PM2.5 at the offshore site. A consistent decrease of secondary sulfate and nitrate contribution to PM2.5 suggested the transportation of aged particles from the west-side to the east-side of the Taiwan Strait. PMID:26973085

  4. The production of fine grained magnesium alloys through thermomechanical processing for the optimization of microstructural and mechanical properties

    NASA Astrophysics Data System (ADS)

    Young, John Paul

    The low density and high strength to weight ratio of magnesium alloys makes them ideal candidates to replace many of the heavier steel and aluminum alloys currently used in the automotive and other industries. Although cast magnesium alloys components have a long history of use in the automotive industry, the integration of wrought magnesium alloys components has been hindered by a number of factors. Grain refinement through thermomechanical processing offers a possible solution to many of the inherent problems associated with magnesium alloys. This work explores the development of several thermomechanical processing techniques and investigates their impact on the microstructural and mechanical properties of magnesium alloys. In addition to traditional thermomechanical processing, this work includes the development of new severe plastic deformation techniques for the production of fine grain magnesium plate and pipe and develops a procedure by which the thermal microstructural stability of severely plastically deformed microstructures can be assessed.

  5. Advanced FTIR technology for the chemical characterization of product wafers

    NASA Astrophysics Data System (ADS)

    Rosenthal, P. A.; Bosch-Charpenay, S.; Xu, J.; Yakovlev, V.; Solomon, P. R.

    2001-01-01

    Advances in chemically sensitive diagnostic techniques are needed for the characterization of compositionally variable materials such as chemically amplified resists, low-k dielectrics and BPSG films on product wafers. In this context, Fourier Transform Infrared (FTIR) reflectance spectroscopy is emerging as a preferred technique to characterize film chemistry and composition, due to its non-destructive nature and excellent sensitivity to molecular bonds and free carriers. While FTIR has been widely used in R&D environments, its application to mainstream production metrology and process monitoring on product wafers has historically been limited. These limitations have been eliminated in a series of recent FTIR technology advances, which include the use of 1) new sampling optics, which suppress artifact backside reflections and 2) comprehensive model-based analysis. With these recent improvements, it is now possible to characterize films on standard single-side polished product wafers with much simpler training wafer sets and machine-independent calibrations. In this new approach, the chemistry of the films is tracked via the measured infrared optical constants as opposed to conventional absorbance measurements. The extracted spectral optical constants can then be reduced to a limited set of parameters for process control. This paper describes the application of this new FTIR methodology to the characterization of 1) DUV photoresists after various processing steps, 2) low-k materials of different types and after various curing conditions, and 3) doped glass BPSG films of various concentration and, for the first time, widely different thicknesses. Such measurements can be used for improved process control on actual product wafers.

  6. Size distribution, chemical composition, and hygroscopicity of fine particles emitted from an oil-fired heating plant.

    PubMed

    Happonen, Matti; Mylläri, Fanni; Karjalainen, Panu; Frey, Anna; Saarikoski, Sanna; Carbone, Samara; Hillamo, Risto; Pirjola, Liisa; Häyrinen, Anna; Kytömäki, Jorma; Niemi, Jarkko V; Keskinen, Jorma; Rönkkö, Topi

    2013-12-17

    Heavy fuel oil (HFO) is a commonly used fuel in industrial heating and power generation and for large marine vessels. In this study, the fine particle emissions of a 47 MW oil-fired boiler were studied at 30 MW power and with three different fuels. The studied fuels were HFO, water emulsion of HFO, and water emulsion of HFO mixed with light fuel oil (LFO). With all the fuels, the boiler emitted considerable amounts of particles smaller than 200 nm in diameter. Further, these small particles were quite hygroscopic even as fresh and, in the case of HFO+LFO emulsion, the hygroscopic growth of the particles was dependent on particle size. The use of emulsions and the addition of LFO to the fuel had a reducing effect on the hygroscopic growth of particles. The use of emulsions lowered the sulfate content of the smallest particles but did not affect significantly the sulfate content of particles larger than 42 nm and, further, the addition of LFO considerably increased the black carbon content of particulate matter. The results indicate that even the fine particles emitted from HFO based combustion can have a significant effect on cloud formation, visibility, and air quality.

  7. Identification of coniferous fine roots to species using ribosomal PCR products of pooled root samples

    EPA Science Inventory

    Background/Question/Methods To inform an individual-based forest stand model emphasizing belowground competition, we explored the potential of using the relative abundances of ribosomal PCR products from pooled and milled roots, to allocate total root biomass to each of the thre...

  8. Identification of coniferous fine roots to species using ribosomal PCR products of pooled root samples

    EPA Science Inventory

    Background/Question/Methods To inform an individual-based forest stand model emphasizing belowground competition, we explored the potential of using the relative abundances of ribosomal PCR products from pooled and milled roots, to allocate total root biomass to each of the thre...

  9. Early quark production and approach to chemical equilibrium

    NASA Astrophysics Data System (ADS)

    Gelfand, D.; Hebenstreit, F.; Berges, J.

    2016-04-01

    We perform real-time lattice simulations of out-of-equilibrium quark production in non-Abelian gauge theory in 3 +1 dimensions. Our simulations include the backreaction of quarks onto the dynamical gluon sector, which is particularly relevant for strongly correlated quarks. We observe fast isotropization and universal behavior of quarks and gluons at weak coupling and establish a quantitative connection to previous pure glue results. In order to understand the strongly correlated regime, we perform simulations for a large number of flavors and compare them to those obtained with two light quark flavors. By doing this we are able to provide estimates of the chemical equilibration time.

  10. Reduced hazard chemicals for solid rocket motor production

    NASA Technical Reports Server (NTRS)

    Caddy, Larry A.; Bowman, Ross; Richards, Rex A.

    1995-01-01

    During the last three years. the NASA/Thiokol/industry team has developed and started implementation of an environmentally sound manufacturing plan for the continued production of solid rocket motors. NASA Marshall Space Flight Center (MSFC) and Thiokol Corporation have worked with other industry representatives and the U.S. Environmental Protection Agency (EPA) to prepare a comprehensive plan to eliminate all ozone depleting chemicals from manufacturing processes and reduce the use of other hazardous materials used to produce the space shuttle reusable solid rocket motors. The team used a classical approach for problem-solving combined with a creative synthesis of new approaches to attack this challenge.

  11. Reduced hazard chemicals for solid rocket motor production

    NASA Technical Reports Server (NTRS)

    Caddy, Larry A.; Bowman, Ross; Richards, Rex A.

    1995-01-01

    During the last three years. the NASA/Thiokol/industry team has developed and started implementation of an environmentally sound manufacturing plan for the continued production of solid rocket motors. NASA Marshall Space Flight Center (MSFC) and Thiokol Corporation have worked with other industry representatives and the U.S. Environmental Protection Agency (EPA) to prepare a comprehensive plan to eliminate all ozone depleting chemicals from manufacturing processes and reduce the use of other hazardous materials used to produce the space shuttle reusable solid rocket motors. The team used a classical approach for problem-solving combined with a creative synthesis of new approaches to attack this challenge.

  12. Chemical characterization of dissolvable tobacco products promoted to reduce harm.

    PubMed

    Rainey, Christina L; Conder, Paige A; Goodpaster, John V

    2011-03-23

    In 2009, the R. J. Reynolds Tobacco Co. released a line of dissolvable tobacco products that are marketed as an alternative to smoking in places where smoking is prohibited. These products are currently available in Indianapolis, IN, Columbus, OH, and Portland, OR. This paper describes the chemical characterization of four such products by gas chromatography-mass spectrometry (GC-MS). The dissolvable tobacco products were extracted and prepared by ultrasonic extraction using acetone, trimethylsilyl derivatization, and headspace solid phase microextraction (SPME). The following compounds were identified in the dissolvables using either ultrasonic extractions or trimethylsilyl derivatization: nicotine, ethyl citrate, palmitic acid, stearic acid, sorbitol, glycerol, and xylitol. The following compounds were identified in the dissolvables using headspace SPME: nicotine, ethyl citrate, cinnamaldehyde, coumarin, vanillin, and carvone. With the exception of nicotine, the compounds identified thus far in the dissolvables are either flavoring compounds or binders. The concentration of free nicotine in the dissolvables was determined from the Henderson-Hasselbalch equation and by measuring the pH and nicotine concentration by GC-MS. The results presented here are the first to reveal the complexity of dissolvable tobacco products and may be used to assess potential oral health effects.

  13. Soursop (Annona muricata) vinegar production and its chemical compositions

    NASA Astrophysics Data System (ADS)

    Ho, Chin Wai; Lazim, Azwan Mat; Fazry, Shazrul; Zaki, Umi Kalsum Hj Hussain; Lim, Seng Joe

    2016-11-01

    Vinegar is a liquid product that undergoes double fermentations, which are alcoholic and acetous fermentation. Sugar source was converted to ethanol in alcoholic fermentation, meanwhile ethanol was oxidised to acetic acid during acetous fermentation. Soursop (Annona muricata) was the starting material in this study, as it is easily available in Malaysia. Its highly aromatic, juicy and distinctive flavours enables the production of high quality vinegar. The objective of this research is to produce good quality soursop vinegar as an innovative method to preserve and utilise the soursop fruit in Malaysia and to determine its chemical compositions. It was found that the sugar content reduces over time, and it is inversely proportional to the ethanol concentration, due to the production of ethanol from sugar. Acetic acid was also found to increase with increasing fermentation time. pH showed no significant difference (p>0.05) in the reduction of sugar and the production of ethanol. However, significantly higher (p<0.05) production of acetic acid was observed at pH 5.0 and 5.5, compared to that at pH 4.5. There were no significant differences (p > 0.05) in Vitamin C contents in all soursop vinegar samples produced using different treatments.

  14. Manipulating respiratory levels in Escherichia coli for aerobic formation of reduced chemical products.

    PubMed

    Zhu, Jiangfeng; Sánchez, Ailen; Bennett, George N; San, Ka-Yiu

    2011-11-01

    Optimizing the productivity of bioengineered strains requires balancing ATP generation and carbon atom conservation through fine-tuning cell respiration and metabolism. Traditional approaches manipulate cell respiration by altering air feeding, which are technically difficult especially in large bioreactors. An approach based on genetic regulation may better serve this purpose. With excess oxygen supply to the culture, we efficiently manipulated Escherichia coli cell respiration by adding different amount of coenzyme Q1 to strains lacking the ubiCA genes, which encode two critical enzymes for ubiquinone synthesis. As a proof-of-concept, the metabolic effect of the ubiCA gene knockout and coenzyme Q1 supplementation were characterized, and the metabolic profiles of the experimental strains showed clear correlations with coenzyme Q1 concentrations. Further proof-of-principle experiments were performed to illustrate that the approach can be used to optimize cell respiration for the production of chemicals of interest such as ethanol. This study showed that controlled respiration through genetic manipulation can be exploited to allow much larger operating windows for reduced product formation even under fully aerobic conditions.

  15. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... additionally planned production of Schedule 3 chemicals. 714.3 Section 714.3 Commerce and Foreign Trade... COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance declaration requirements for additionally planned production of Schedule 3 chemicals. (a)...

  16. Fine tuning of process parameters for improving briquette production from palm kernel shell gasification waste.

    PubMed

    Bazargan, Alireza; Rough, Sarah L; McKay, Gordon

    2017-05-05

    Palm kernel shell biochars (PKSB) ejected as residues from a gasifier have been used for solid fuel briquette production. With this approach, palm kernel shells can be used for energy production twice: first, by producing rich syngas during gasification; second, by compacting the leftover residues from gasification into high calorific value briquettes. Herein, the process parameters for the manufacture of PKSB biomass briquettes via compaction are optimized. Two possible optimum process scenarios are considered. In the first, the compaction speed is increased from 0.5 to 10 mm/s, the compaction pressure is decreased from 80 Pa to 40 MPa, the retention time is reduced from 10 s to zero, and the starch binder content of the briquette is halved from 0.1 to 0.05 kg/kg. With these adjustments, the briquette production rate increases by more than 20-fold; hence capital and operational costs can be reduced and the service life of compaction equipment can be increased. The resulting product satisfactorily passes tensile (compressive) crushing strength and impact resistance tests. The second scenario involves reducing the starch weight content to 0.03 kg/kg, while reducing the compaction pressure to a value no lower than 60 MPa. Overall, in both cases, the PKSB biomass briquettes show excellent potential as a solid fuel with calorific values on par with good-quality coal. CHNS: carbon, hydrogen, nitrogen, sulfur; FFB: fresh fruit bunch(es); HHV: higher heating value [J/kg]; LHV: lower heating value [J/kg]; PKS: palm kernel shell(s); PKSB: palm kernel shell biochar(s); POME: palm oil mill effluent; RDF: refuse-derived fuel; TGA: thermogravimetric analysis.

  17. Chemical conversion of energetic materials to higher value products

    SciTech Connect

    Mitchell, A.R.; Sanner, R.D.

    1993-03-01

    Objective of this program is to examine new routes for disposal of energetic materials, as there is need to reduce the stockpile of conventional munitions. Disposal through destruction (burning, detonation) is less feasible today due to environmental, cost and safety concerns. Chemical conversion of energetic materials to higher value products useful in civilian and military applications is one area being explored. Initial focus has been on the conversion of TNT to other materials. Reduction of TNT to aminodinitrotoluenes, diaminonitrotoluenes and triaminotoluene is well known. Conversion of these TNT reduction products to corresponding iminodiacetic acid derivatives by N-dialkylation with chloroacetic acid should provide chelators of heavy metals. The preparation and characterization of chelating resins derived from TNT-related molecules and polystyrene are described.

  18. Utilization of oleo-chemical industry by-products for biosurfactant production.

    PubMed

    Bhardwaj, Garima; Cameotra, Swaranjit Singh; Chopra, Harish Kumar

    2013-11-21

    Biosurfactants are the surface active compounds produced by micro-organisms. The eco-friendly and biodegradable nature of biosurfactants makes their usage more advantageous over chemical surfactants. Biosurfactants encompass the properties of dropping surface tension, stabilizing emulsions, promoting foaming and are usually non- toxic and biodegradable. Biosurfactants offer advantages over their synthetic counterparts in many applications ranging from environmental, food, and biomedical, cosmetic and pharmaceutical industries. The important environmental applications of biosurfactants include bioremediation and dispersion of oil spills, enhanced oil recovery and transfer of crude oil. The emphasis of present review shall be with reference to the commercial production, current developments and future perspectives of a variety of approaches of biosurfactant production from the micro-organisms isolated from various oil- contaminated sites and from the by-products of oleo-chemical industry wastes/ by-products viz. used edible oil, industrial residues, acid oil, deodorizer distillate, soap-stock etc.

  19. Utilization of oleo-chemical industry by-products for biosurfactant production

    PubMed Central

    2013-01-01

    Biosurfactants are the surface active compounds produced by micro-organisms. The eco-friendly and biodegradable nature of biosurfactants makes their usage more advantageous over chemical surfactants. Biosurfactants encompass the properties of dropping surface tension, stabilizing emulsions, promoting foaming and are usually non- toxic and biodegradable. Biosurfactants offer advantages over their synthetic counterparts in many applications ranging from environmental, food, and biomedical, cosmetic and pharmaceutical industries. The important environmental applications of biosurfactants include bioremediation and dispersion of oil spills, enhanced oil recovery and transfer of crude oil. The emphasis of present review shall be with reference to the commercial production, current developments and future perspectives of a variety of approaches of biosurfactant production from the micro-organisms isolated from various oil- contaminated sites and from the by-products of oleo-chemical industry wastes/ by-products viz. used edible oil, industrial residues, acid oil, deodorizer distillate, soap-stock etc. PMID:24262384

  20. Acacia koa forest classification and productivity assessment across environmental gradients in Hawaii using fine resolution remotely sensed imagery

    NASA Astrophysics Data System (ADS)

    Martinez Morales, R.; Idol, T.; Chen, Q.

    2009-05-01

    Koa (Acacia koa) is an important native tree species in Hawaii economically and ecologically. Different Acacia koa (koa) forest types are found across the elevation and rainfall gradients typical of the Hawaiian Islands. The purpose of this study was to develop methodologies to differentiate these forests and to assess indices and indicators of forest productivity across these gradients using fine resolution remotely sensed imagery. IKONOS satellite imagery was analyzed using advanced statistical modeling and compared to field measurements of productivity indices. The calculation of several vegetation indices that are commonly used in vegetation studies, allowed classification of various koa forest types into micro-regions in wet and dry locations across elevation gradients ranging from 300-850 m. Vegetation indices and image texture parameters strongly related to tree height, N, P and specific leaf area and less strongly with leaf area index and basal area across gradient sites. This allowed development of statistical models that can be used in the assessment of koa forest productivity indices at landscape and regional scales. This will also allow for the application of specific forest management strategies suitable to the environmental conditions and plant requirements for optimal tree growth in each micro-region.

  1. Precipitation Analysis at Fine Time Scales using TRMM and Other Satellites: Real-time and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold; Gu, Guo-Jon

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the TRMM Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) by the end of 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25" latitude-longitude resolution over the latitude range from 5O0N-50"S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, includmg: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  2. Precipitation Analysis at Fine Time Scales using TRMM and Other Satellites: Realtime and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold; Gu, Guojon

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the TRMM Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) by the end of 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25 deg latitude-longitude resolution over the latitude range from 50 deg N-50 deg S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, including: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  3. Precipitation Analysis at Fine Time Scales Using Multiple Satellites: Real-time and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) in 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25" latitude-longitude resolution over the latitude range from 5O"N-5O0S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, including: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  4. Precipitation Analysis at Fine Time Scales using TRMM and Other Satellites: Realtime and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold; Gu, Guojon

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the TRMM Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) by the end of 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25 deg latitude-longitude resolution over the latitude range from 50 deg N-50 deg S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, including: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  5. Precipitation Analysis at Fine Time Scales Using Multiple Satellites: Real-time and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) in 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25" latitude-longitude resolution over the latitude range from 5O"N-5O0S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, including: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  6. Precipitation Analysis at Fine Time Scales using TRMM and Other Satellites: Real-time and Research Products and Applications

    NASA Technical Reports Server (NTRS)

    Adler, Robert; Huffman, George; Bolvin, David; Nelkin, Eric; Curtis, Scott; Pierce, Harold; Gu, Guo-Jon

    2004-01-01

    Quasi-global precipitation analyses at fine time scales (3-hr) are described. TRMM observations (radar and passive microwave) are used to calibrate polar-orbit microwave observations from SSM/I (and other satellites instruments, including AMSR and AMSU) and geosynchronous IR observations. The individual data sets are then merged using a priority order based on quality to form the TRMM Multi-satellite Precipitation Analysis (MPA). Raingauge information is used to help constrain the satellite-based estimates over land. The TRMM standard research product (Version 6 3B-42 of the TRMM products) will be available for the entire TRMM period (January 1998-present) by the end of 2004. The real-time version of this merged product has been produced over the past two years and is available on the U.S. TRMM web site (trmm.gsfc.nasa.gov) at 0.25" latitude-longitude resolution over the latitude range from 5O0N-50"S. Validation of daily totals indicates good results, with limitations noted in mid-latitude winter over land and regions of shallow, orographic precipitation. Various applications of these estimates are described, includmg: 1) detecting potential floods in near real-time; 2) analyzing Indian Ocean precipitation variations related to the initiation of El Nino; 3) determining characteristics of the African monsoon; and 4) analysis of diurnal variations.

  7. Precise precursor rebalancing for isoprenoids production by fine control of gapA expression in Escherichia coli.

    PubMed

    Jung, Juyoung; Lim, Jae Hyung; Kim, Se Yeon; Im, Dae-Kyun; Seok, Joo Yeon; Lee, Seung-Jae V; Oh, Min-Kyu; Jung, Gyoo Yeol

    2016-11-01

    Biosynthesis of isoprenoids via the 1-deoxy-D-xylulose-5-phosphate (DXP) pathway requires equimolar glyceraldehyde 3-phosphate and pyruvate to divert carbon flux toward the products of interest. Here, we demonstrate that precursor balancing is one of the critical steps for the production of isoprenoids in Escherichia coli. First, the implementation of the synthetic lycopene production pathway as a model system and the amplification of the native DXP pathway were accomplished using synthetic constitutive promoters and redesigned 5'-untranslated regions (5'-UTRs). Next, fine-controlled precursor balancing was investigated by tuning phosphoenolpyruvate synthase (PpsA) or glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The results showed that tuning-down of gapA improved the specific lycopene content by 45% compared to the overexpression of ppsA. The specific lycopene content in the strains with down-regulated gapA increased by 97% compared to that in the parental strain. Our results indicate that gapA is the best target for precursor balancing to increase biosynthesis of isoprenoids.

  8. The symmetries of the fine gradings of sl(n{sup k},C) associated with direct product of Pauli groups

    SciTech Connect

    Han Gang

    2010-09-15

    A grading of a Lie algebra is called fine if it could not be further refined. For a fine grading of a simple Lie algebra, we define its Weyl group to describe the symmetry of this grading. It is already known that the Weyl group of the fine grading of sl(n,C) induced by the action of the group {Pi}{sub n} of the generalized Pauli matrices of rank n is SL(2,Z{sub n}), where Z{sub n} is the cyclic group of order n. In this paper, we consider the fine grading of sl(n{sup k},C) induced by the action of the group of k-fold tensor product of the generalized Pauli matrices of rank n. We prove that its Weyl group is Sp(2k,Z{sub n}) and is generated by transvections; therefore, this generalizes the previous result.

  9. Chemical Looping Reforming for H2, CO and Syngas Production

    SciTech Connect

    Bhavsar,Saurabh; Najera,Michelle; Solunke,Rahul; Veser,Götz

    2001-06-06

    We demonstrate that the extension of CLC onto oxidants beyond air opens new, highly efficient pathways for production of ultra-pure hydrogen, activation of CO{sub 2} via reduction to CO, and are currently working on production of syngas using nanocomposite Fe-BHA. CLR hold great potential due to fuel flexibility and CO{sub 2} capture. Chemical Looping Combustion (CLC) is a novel clean combustion technology which offers an elegant and highly efficient route for fossil fuel combustion. In CLC, combustion of a fuel is broken down into two spatially separated steps. In the reducer, the oxygen carrier (typically a metal) supplies the stoichiometric oxygen required for fuel combustion. In the oxidizer, the oxygen-depleted carrier is then re-oxidized with air. After condensation of steam from the effluent of the reducer, a high-pressure, high-purity sequestration-ready CO{sub 2} stream is obtained. In the present study, we apply the CLC principle to the production of high-purity H{sub 2}, CO, and syngas streams by replacing air with steam and/or CO{sub 2} as oxidant, respectively. Using H{sub 2}O as oxidant, pure hydrogen streams can be obtained. Similarly, using CO{sub 2} as oxidant, CO is obtained, thus opening an efficient route for CO{sub 2} utilization. Using steam and CO{sub 2} mixtures for carrier oxidation should thus allow production of syngas with adjustable CO:H{sub 2} ratios. Overall, these processes result in Chemical Looping Reforming (CLR), i.e. the net overall reaction is the steam and/or dry reforming of the respective fuel.

  10. Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM 2.5) Fraction of Coal Combustion Ash

    SciTech Connect

    R. S. Perrone; J. G. Groppo; T. L. Robl

    2006-07-20

    Three types of chemically and functionally different thermoplastic polymers have been chosen for evaluation with the fly ash derived filler: high density polyethylene (HDPE), thermoplastic elastomer (TPE) and polyethylene terephthalate (PET). The selections were based on volumes consumed in commercial and recycled products. The reference filler selected for comparison was 3 {micro}m calcium carbonate, a material which is commonly used with all three types of polymers. A procedure to prepare filled polymers has been developed and the polymer/filler blends have been prepared. Selected samples of filled polymers were subjected to SEM analysis to verify that the fly ash derived filler and the calcium carbonate were well dispersed. Material taken from a utility ash pond was classified using a novel combination of hydraulic and lamellar classifiers to produce an ultra-fine ash product. This product was dried and used in a series of tests to determine its potential as a filler in plastics. The general properties of the ultra-fine ash from several runs are as follows: D{sub 50}: 3-5 {micro}m; Specific gravity: {approx}2.41; Loss on ignition: 2-3%; Carbon content: 1-2%; Color: dark grey on content: 1-2%; and Morphology: spherical. The addition of fillers increased the modulus of the HDPE composite, but decreased both the offset yield stress and offset yield strain, showing that the fillers essentially made the composite stiffer but the transition to plastic deformation occurred earlier in filled HDPE as stress was applied. Similar results were obtained with TPE, however, the decrease in either stress or strain at offset yield were not as significant. Dynamic mechanical analyses (DMA) were also completed and showed that although there were some alterations in the properties of the HDPE and TPE, with the addition of CaCO{sub 3} and fly ash, the alterations are small, and more importantly, transition temperatures are not altered. A utility patent on the design of the hydraulic

  11. [Residual chemicals in silicone rubber products for food contact use].

    PubMed

    Kawamura, Y; Nakajima, A; Mutsuga, M; Yamada, T; Maitani, T

    2001-10-01

    The residues of additives and other chemicals in 23 kinds of silicone rubber products for food contact use, including nipples, packing and spatulas, were investigated by GC/MS. The packing and spatulas contained 80-480 micrograms/g of BHT, 60-5,830 micrograms/g of di(2-ethylhexyl) phthalate (DEHP), and 60-80 micrograms/g of dibutyl phthalate, while the nipples contained no additives. All of the samples contained 15 to 20 peaks of polydimethylcyclosiloxanes. Dodecamethylcyclohexasiloxane (D6) to tetratriacomethylcycloheptadecasiloxane (D17) were confirmed, and other larger siloxanes up to pentacontamethylcyclopentacosasiloxane (D25) were estimated. A rough estimate of the total cyclosiloxane content was 3,310-14,690 micrograms/g. They might be mainly unreacted materials or by-products, and some of them might be additives. Based on the migration test, no chemicals were released into 20% ethanol at 60 degrees C for 30 min, though DEHP and the polydimethylcyclosiloxanes were released into n-heptane at 25 degrees C for 60 min.

  12. Chemical Characterization and Reactivity of Fuel-Oxidizer Reaction Product

    NASA Technical Reports Server (NTRS)

    David, Dennis D.; Dee, Louis A.; Beeson, Harold D.

    1997-01-01

    Fuel-oxidizer reaction product (FORP), the product of incomplete reaction of monomethylhydrazine and nitrogen tetroxide propellants prepared under laboratory conditions and from firings of Shuttle Reaction Control System thrusters, has been characterized by chemical and thermal analysis. The composition of FORP is variable but falls within a limited range of compositions that depend on three factors: the fuel-oxidizer ratio at the time of formation; whether the composition of the post-formation atmosphere is reducing or oxidizing; and the reaction or post-reaction temperature. A typical composition contains methylhydrazinium nitrate, ammonium nitrate, methylammonium nitrate, and trace amounts of hydrazinium nitrate and 1,1-dimethylhydrazinium nitrate. Thermal decomposition reactions of the FORP compositions used in this study were unremarkable. Neither the various compositions of FORP, the pure major components of FORP, nor mixtures of FORP with propellant system corrosion products showed any unusual thermal activity when decomposed under laboratory conditions. Off-limit thruster operations were simulated by rapid mixing of liquid monomethylhydrazine and liquid nitrogen tetroxide in a confined space. These tests demonstrated that monomethylhydrazine, methylhydrazinium nitrate, ammonium nitrate, or Inconel corrosion products can induce a mixture of monomethylhydrazine and nitrogen tetroxide to produce component-damaging energies. Damaging events required FORP or metal salts to be present at the initial mixing of monomethylhydrazine and nitrogen tetroxide.

  13. 9 CFR 318.16 - Pesticide chemicals and other residues in products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Pesticide chemicals and other residues... PREPARATION OF PRODUCTS General § 318.16 Pesticide chemicals and other residues in products. (a) Nonmeat ingredients. Residues of pesticide chemicals, food additives and color additives or other substances in or on...

  14. 9 CFR 318.16 - Pesticide chemicals and other residues in products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Pesticide chemicals and other residues... PREPARATION OF PRODUCTS General § 318.16 Pesticide chemicals and other residues in products. (a) Nonmeat ingredients. Residues of pesticide chemicals, food additives and color additives or other substances in or on...

  15. 9 CFR 318.16 - Pesticide chemicals and other residues in products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Pesticide chemicals and other residues... PREPARATION OF PRODUCTS General § 318.16 Pesticide chemicals and other residues in products. (a) Nonmeat ingredients. Residues of pesticide chemicals, food additives and color additives or other substances in or on...

  16. 9 CFR 318.16 - Pesticide chemicals and other residues in products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Pesticide chemicals and other residues... PREPARATION OF PRODUCTS General § 318.16 Pesticide chemicals and other residues in products. (a) Nonmeat ingredients. Residues of pesticide chemicals, food additives and color additives or other substances in or on...

  17. 9 CFR 318.16 - Pesticide chemicals and other residues in products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Pesticide chemicals and other residues... PREPARATION OF PRODUCTS General § 318.16 Pesticide chemicals and other residues in products. (a) Nonmeat ingredients. Residues of pesticide chemicals, food additives and color additives or other substances in or on...

  18. Annual cycle and temperature dependence of pinene oxidation products and other water-soluble organic compounds in coarse and fine aerosol samples

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Müller, L.; Winterhalter, R.; Moortgat, G. K.; Hoffmann, T.; Pöschl, U.

    2010-05-01

    Filter samples of fine and coarse particulate matter were collected over a period of one year and analyzed for water-soluble organic compounds, including the pinene oxidation products pinic acid, pinonic acid, 3-methyl-1,2,3-butanetricarboxylic acid (3-MBTCA) and a variety of dicarboxylic acids (C5-C16) and nitrophenols. Seasonal variations and other characteristic features are discussed with regard to aerosol sources and sinks and data from other studies and regions. The ratios of adipic acid (C6) and phthalic acid (Ph) to azelaic acid (C9) indicate that the investigated aerosols samples were mainly influenced by biogenic sources. An Arrhenius-type correlation was found between the 3-MBTCA concentration and inverse temperature. Model calculations suggest that the temperature dependence is largely due to enhanced emissions and OH radical concentrations at elevated temperatures, whereas the influence of gas-particle partitioning appears to play a minor role. Enhanced ratios of pinic acid to 3-MBTCA indicate strong chemical aging of the investigated aerosols in summer and spring. Acknowledgment: The authors would like to thank M. Claeys for providing synthetic 3-methyl-1,2,3-butanetricarboxylic acid standards for LC-MS analysis and J. Fröhlich for providing filter samples and related information.

  19. The chemical versatility of natural-product assembly lines.

    PubMed

    Walsh, Christopher T

    2008-01-01

    Microbial natural products of both polyketide and nonribosomal peptide origin have been and continue to be important therapeutic agents as antibiotics, immunosupressants, and antitumor drugs. Because the biosynthetic genes for these metabolites are clustered for coordinate regulation, the sequencing of bacterial genomes continues to reveal unanticipated biosynthetic capacity for novel natural products. The re-engineering of pathways for such secondary metabolites to make novel molecular variants will be enabled by understanding of the chemical logic and protein machinery in the producer microbes. This Account analyzes the chemical principles and molecular logic that allows simple primary metabolite building blocks to be converted to complex architectural scaffolds of polyketides (PK), nonribosomal peptides (NRP), and NRP-PK hybrids. The first guiding principle is that PK and NRP chains are assembled as thioseters tethered to phosphopantetheinyl arms of carrier proteins that serve as thiotemplates for chain elongation. The second principle is that gate keeper protein domains select distinct monomers to be activated and incorporated with positional specificity into the growing natural product chains. Chain growth is via thioclaisen condensations for PK and via amide bond formation for elongating NRP chains. Release of the full length acyl/peptidyl chains is mediated by thioesterases, some of which catalyze hydrolysis while others catalyze regiospecific macrocyclization to build in conformational constraints. Tailoring of PK and NRP chains, by acylation, alkylation, glycosylation, and oxidoreduction, occurs both during tethered chain growth and after thioesterase-mediated release. Analysis of the types of protein domains that carry out chain initiation, elongation, tailoring, and termination steps gives insight into how NRP and PK biosynthetic assembly lines can be redirected to make novel molecules.

  20. Chemical and physical properties of dry flue gas desulfurization products.

    PubMed

    Kost, David A; Bigham, Jerry M; Stehouwer, Richard C; Beeghly, Joel H; Fowler, Randy; Traina, Samuel J; Wolfe, William E; Dick, Warren A

    2005-01-01

    Beneficial and environmentally safe recycling of flue gas desulfurization (FGD) products requires detailed knowledge of their chemical and physical properties. We analyzed 59 dry FGD samples collected from 13 locations representing four major FGD scrubbing technologies. The chemistry of all samples was dominated by Ca, S, Al, Fe, and Si and strong preferential partitioning into the acid insoluble residue (i.e., coal ash residue) was observed for Al, Ba, Be, Cr, Fe, Li, K, Pb, Si, and V. Sulfur, Ca, and Mg occurred primarily in water- or acid-soluble forms associated with the sorbents or scrubber reaction products. Deionized water leachates (American Society for Testing and Materials [ASTM] method) and dilute acetic acid leachates (toxicity characteristic leaching procedure [TCLP] method) had mean pH values of >11.2 and high mean concentrations of S primarily as SO(2-)4 and Ca. Concentrations of Ag, As, Ba, Cd, Cr, Hg, Pb, and Se (except for ASTM Se in two samples) were below drinking water standards in both ASTM and TCLP leachates. Total toxicity equivalents (TEQ) of dioxins, for two FGD products used for mine reclamation, were 0.48 and 0.53 ng kg(-1). This was similar to the background level of the mine spoil (0.57 ng kg(-1)). The FGD materials were mostly uniform in particle size. Specific surface area (m2 g(-1)) was related to particle size and varied from 1.3 for bed ash to 9.5 for spray dryer material. Many of the chemical and physical properties of these FGD samples were associated with the quality of the coal rather than the combustion and SO2 scrubbing processes used.

  1. CO2 and N-fertilization effects on fine-root length, production, and mortality: a 4-year ponderosa pine study.

    PubMed

    Phillips, Donald L; Johnson, Mark G; Tingey, David T; Storm, Marjorie J; Ball, J Timothy; Johnson, Dale W

    2006-06-01

    We conducted a 4-year study of juvenile Pinus ponderosa fine root (< or =2 mm) responses to atmospheric CO2 and N-fertilization. Seedlings were grown in open-top chambers at three CO2 levels (ambient, ambient+175 mumol/mol, ambient+350 mumol/mol) and three N-fertilization levels (0, 10, 20 g m(-2) year(-1)). Length and width of individual roots were measured from minirhizotron video images bimonthly over 4 years starting when the seedlings were 1.5 years old. Neither CO2 nor N-fertilization treatments affected the seasonal patterns of root production or mortality. Yearly values of fine-root length standing crop (m m(-2)), production (m m(-2) year(-1)), and mortality (m m(-2) year(-1)) were consistently higher in elevated CO2 treatments throughout the study, except for mortality in the first year; however, the only statistically significant CO2 effects were in the fine-root length standing crop (m m(-2)) in the second and third years, and production and mortality (m m(-2) year(-1)) in the third year. Higher mortality (m m(-2) year(-1)) in elevated CO2 was due to greater standing crop rather than shorter life span, as fine roots lived longer in elevated CO2. No significant N effects were noted for annual cumulative production, cumulative mortality, or mean standing crop. N availability did not significantly affect responses of fine-root standing crop, production, or mortality to elevated CO2. Multi-year studies at all life stages of trees are important to characterize belowground responses to factors such as atmospheric CO2 and N-fertilization. This study showed the potential for juvenile ponderosa pine to increase fine-root C pools and C fluxes through root mortality in response to elevated CO2.

  2. Improving putrescine production by Corynebacterium glutamicum by fine-tuning ornithine transcarbamoylase activity using a plasmid addiction system.

    PubMed

    Schneider, Jens; Eberhardt, Dorit; Wendisch, Volker F

    2012-07-01

    Corynebacterium glutamicum shows a great potential for the production of the polyamide monomer putrescine (1,4-diaminobutane). Previously, we constructed the putrescine-producing strain PUT1 by deletion of argF, the gene for ornithine transcarbamoylase (OTC), and argR, encoding the L-arginine repressor, combined with heterologous expression of the Escherichia coli gene for L-ornithine decarboxylase SpeC. As a consequence of argF deletion, this strain requires supplementation of L-arginine and shows growth-decoupled putrescine production. To avoid costly supplementation with L-arginine and the strong feedback inhibition of the key enzyme N-acetylglutamate kinase (ArgB) by L-arginine, a plasmid addiction system for low-level argF expression was developed. By fine-tuning argF expression through modifications of the promoter, the translational start codon and/or the ribosome binding site, high productivity and titer could be obtained. OTC activity varied almost thousandfold between 960 and 1 mU mg⁻¹ resulting in putrescine yields on glucose from less than 0.001 up to 0.26 g g⁻¹, the highest yield in bacteria reported to date. The most promising strain, designated PUT21, was characterized comprehensively. PUT21 strain grew with a rate of 0.19 h⁻¹ in mineral salt medium without the need for L-arginine supplementation and produced putrescine with a yield of 0.16 g g⁻¹ glucose at a volumetric productivity of 0.57 g L⁻¹ h⁻¹ and a specific productivity of 0.042 g g⁻¹ h⁻¹. The carbon balance suggested that no major unidentified by-product was produced. Compared to the first-generation strain PUT1, the putrescine yield observed with PUT21 was increased by 60%. In fed-batch cultivation with C. glutamicum PUT21, a putrescine titer of 19 g L⁻¹ at a volumetric productivity of 0.55 g L⁻¹ h⁻¹ and a yield of 0.16 g g⁻¹ glucose could be achieved. Moreover, while plasmid segregation of the initial strain required antibiotic selection

  3. Fine particle emissions in three different combustion conditions of a wood chip-fired appliance - Particulate physico-chemical properties and induced cell death

    NASA Astrophysics Data System (ADS)

    Leskinen, J.; Tissari, J.; Uski, O.; Virén, A.; Torvela, T.; Kaivosoja, T.; Lamberg, H.; Nuutinen, I.; Kettunen, T.; Joutsensaari, J.; Jalava, P. I.; Sippula, O.; Hirvonen, M.-R.; Jokiniemi, J.

    2014-04-01

    A biomass combustion reactor with a moving grate was utilised as a model system to produce three different combustion conditions corresponding to efficient, intermediate, and smouldering combustion. The efficient conditions (based on a CO level of approximately 7 mg MJ-1) corresponded to a modern pellet boiler. The intermediate conditions (CO level of approximately 300 mg MJ-1) corresponded to non-optimal settings in a continuously fired biomass combustion appliance. The smouldering conditions (CO level of approximately 2200 mg MJ-1) approached a batch combustion situation. The gaseous and particle emissions were characterised under each condition. Moreover, the ability of fine particles to cause cell death was determined using the particle emissions samples. The physico-chemical properties of the emitted particles and their toxicity were considerably different between the studied combustion conditions. In the efficient combustion, the emitted particles were small in size and large in number. The PM1 emission was low, and it was composed of ash species. In the intermediate and smouldering combustion, the PM1 emission was higher, and the particles were larger in size and smaller in number. In both of these conditions, there were high-emission peaks that produced a significant fraction of the emissions. The PAH emissions were the lowest in the efficient combustion. The smouldering combustion conditions produced the largest PAH emissions. In efficient combustion conditions, the emitted fine particles had the highest potential to cause cell death. This finding was most likely observed because these fine particles were mainly composed of inorganic ash species, and their relative contents of Zn were high. Thus, even the PM1 from optimal biomass combustion might cause health effects, but in these conditions, the particle emissions per energy unit produced were considerably lower.

  4. Hydrocarbons and heavy metals in fine particulates in oil field air: possible impacts on production of natural silk.

    PubMed

    Devi, Gitumani; Devi, Arundhuti; Bhattacharyya, Krishna Gopal

    2016-02-01

    Analyses of fine particulates (PM2.5) from the upper Assam oil fields of India indicated considerable presence of higher hydrocarbons (C22-C35) and heavy metals, Cd, Co, Cr, Cu, Ni, Pb, and Zn. This has raised serious concern for the sustainability of the exotic Muga (Antheraea assama) silk production, which has been a prime activity of a large number of people living in the area. The Muga worm feeds on the leaves of Machilus bombycina plant, and the impacts of air quality on its survival were further investigated by analyzing the leaves of the plant, the plantation soil, and the Muga cocoons. PM2.5 content in the air was much more during the winter due to near calm conditions and high humidity. Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and gas chromatography-mass spectrometer (GC-MS) analysis of PM2.5 showed the presence of higher alkanes (C22-C35) that could be traced to crude oil. Cr, Ni, and Zn were found in higher concentrations in PM2.5, M. bombycina leaves, and the plantation soil indicating a common origin. The winter has been the best period for production of the silk cocoons, and the unhealthy air during this period is likely to affect the production, which is already reflected in the declining yield of Muga cocoons from the area. SEM and protein analyses of the Muga silk fiber produced in the oil field area have exhibited the deteriorating quality of the silk. This is the first report from India on hydrocarbons and associated metals in PM2.5 collected from an oil field and on their possible effects on production of silk by A. assama.

  5. Chemical composition of submicron and fine particulate matter collected in Krakow, Poland. Consequences for the APARIC project.

    PubMed

    Samek, Lucyna; Furman, Leszek; Mikrut, Magdalena; Regiel-Futyra, Anna; Macyk, Wojciech; Stochel, Grażyna; van Eldik, Rudi

    2017-11-01

    Submicron particulate matter containing particles with an aerodynamic diameter ≤1 μm (PM1) are not monitored continuously by Environmental Protection Agencies around the World and are seldom studied. Numerous studies have indicated that people exposed to ultrafine (≤100 nm), submicron and fine particulate matter containing particles with an aerodynamic diameter ≤2.5 μm (PM2.5), can suffer from respiratory track diseases, cardiovascular, immunological or heart diseases and others. Inorganic pollutants containing redox active transition metals and small gaseous molecules, are involved in the generation of reactive oxygen and reactive nitrogen species. Inhalation of this kind of particles can affect immune-toxicity. Environmental pollution may aggravate the course of autoimmune diseases, in particular influence the mechanisms of the autoimmune system. Important factors that influence the toxicity of particulate matter, are particle size distribution, composition and concentration. This report deals with the composition of PM1 and PM2.5 fractions collected in Krakow, Poland. In spring 2015, the mean concentrations of PM1 and PM2.5 were 19 ± 14 and 27 ± 19 μg/m(3), respectively. The PM2.5 fraction contained approximately 70 ± 17% of submicron particulate matter. In spring 2016, the mean concentrations of PM1 and PM2.5 were 12 ± 5 and 22 ± 12 μg/m(3), respectively. The PM2.5 fraction contained approximately 60 ± 15% of submicron particulate matter. The concentrations of the elements Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb in both fractions were determined by X-ray fluorescence spectrometry. Most of the analyzed metals had higher concentrations in the fine fraction than in the submicron one. Concentrations of V and As were below the detection limit in both fractions, whereas concentrations of Mn and Ca were below the detection limits in the PM1 fraction. The results are discussed in terms of the consequences they may have on

  6. Pelletization of fine coals. Final report

    SciTech Connect

    Sastry, K.V.S.

    1995-12-31

    Coal is one of the most abundant energy resources in the US with nearly 800 million tons of it being mined annually. Process and environmental demands for low-ash, low-sulfur coals and economic constraints for high productivity are leading the coal industry to use such modern mining methods as longwall mining and such newer coal processing techniques as froth flotation, oil agglomeration, chemical cleaning and synthetic fuel production. All these processes are faced with one common problem area--fine coals. Dealing effectively with these fine coals during handling, storage, transportation, and/or processing continues to be a challenge facing the industry. Agglomeration by the unit operation of pelletization consists of tumbling moist fines in drums or discs. Past experimental work and limited commercial practice have shown that pelletization can alleviate the problems associated with fine coals. However, it was recognized that there exists a serious need for delineating the fundamental principles of fine coal pelletization. Accordingly, a research program has been carried involving four specific topics: (i) experimental investigation of coal pelletization kinetics, (ii) understanding the surface principles of coal pelletization, (iii) modeling of coal pelletization processes, and (iv) simulation of fine coal pelletization circuits. This report summarizes the major findings and provides relevant details of the research effort.

  7. Synthetic and systems biology for microbial production of commodity chemicals.

    PubMed

    Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J; Keasling, Jay D; Martín, Héctor García

    2016-01-01

    The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges start at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.

  8. Chemical contamination and transformation of soils in hydrocarbon production regions

    NASA Astrophysics Data System (ADS)

    Zamotaev, I. V.; Ivanov, I. V.; Mikheev, P. V.; Nikonova, A. N.

    2015-12-01

    The current concepts of soil pollution and transformation in the regions of hydrocarbon production have been reviewed. The development of an oil field creates extreme conditions for pedogenesis. Tendencies in the radial migration, spatial distribution, metabolism, and accumulation of pollutants (oil, oil products, and attendant heavy metals) in soils of different bioclimatic zones have been analyzed. The radial and lateral mobility of pollution halos is a universal tendency in the technogenic transformation of soils and soil cover in the regions of hydrocarbon production. The biodegradation time of different hydrocarbon compounds strongly varies under different landscape conditions, from several months to several tens of years. The transformation of original (mineral and organic) soils to their technogenic modifications (mechanically disturbed, chemically contaminated, and chemo soils and chemozems) occurs in the impact zone of technogenic hydrocarbon fluxes under any physiographical conditions. The integrated use of the existing methods for the determination of the total content and qualitative composition of bituminous substances and polyaromatic hydrocarbons in combination with the chromatographic determination of normal alkanes and hydrocarbon gases, as well as innovative methods of studies, allows revealing new processes and genetic relationships in soils and studying the functioning of soils and soil cover. The study of the hydrocarbon contamination of soils is important for development of restoration measures and lays the groundwork for the ecological and hygienic regulation based on the zonation of soil and landscape resistance to different pollutants.

  9. Synthetic and systems biology for microbial production of commodity chemicals

    SciTech Connect

    Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J.; Keasling, Jay D.; Martín, Héctor Garcia

    2016-04-07

    The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges start at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.

  10. Synthetic and systems biology for microbial production of commodity chemicals

    PubMed Central

    Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J; Keasling, Jay D; Martín, Héctor García

    2016-01-01

    The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges start at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering. PMID:28725470

  11. Chemical characteristics and source apportionment of fine particulate organic carbon in Hong Kong during high particulate matter episodes in winter 2003

    NASA Astrophysics Data System (ADS)

    Li, Yun-Chun; Yu, Jian Zhen; Ho, Steven Sai Hang; Schauer, James J.; Yuan, Zibing; Lau, Alexis K. H.; Louie, Peter K. K.

    2013-02-01

    PM2.5 samples were collected at six general stations and one roadside station in Hong Kong in two periods of high particulate matter (PM) in 2003 (27 October-4 November and 30 November-13 December). The highest PM2.5 reached 216 μg m- 3 during the first high PM period and 113 μg m- 3 during the second high PM period. Analysis of synoptic weather conditions identified individual sampling days under dominant influence of one of three types of air masses, that is, local, regional and long-range transported (LRT) air masses. Roadside samples were discussed separately due to heavy influences from vehicular emissions. This research examines source apportionment of fine organic carbon (OC) and contribution of secondary organic aerosol on high PM days under different synoptic conditions. Six primary OC (POC) sources (vehicle exhaust, biomass burning, cooking, cigarette smoke, vegetative detritus, and coal combustion) were identified on the basis of characteristic organic tracers. Individual POC source contributions were estimated using chemical mass balance model. In the roadside and the local samples, OC was dominated by the primary sources, accounting for more than 74% of OC. In the samples influenced by regional and LRT air masses, secondary OC (SOC), which was approximated to be the difference between the total measured OC and the apportioned POC, contributed more than 54% of fine OC. SOC was highly correlated with water-soluble organic carbon and sulfate, consistent with its secondary nature.

  12. Physical, chemical and biological controls of nutrient fluxes from fine-grained, organic-rich sediments in the Indian River Lagoon, Florida

    NASA Astrophysics Data System (ADS)

    Fox, A. L.; Trefry, J. H.; Trocine, R. P.; Fox, S. L.; Yan, Y.

    2016-02-01

    Releases and biogeochemical controls of dissolved nitrogen and phosphorus from fine-grained, organic-rich sediments in the Indian River Lagoon, Florida, were determined using (1) interstitial water chemistry, (2) laboratory incubations and experiments, and (3) in situ chambers. Fluxes of nitrogen, essentially all as ammonium ions, and phosphorus, essentially all as orthophosphate ions, averaged 2000 ± 1000 and 130 ± 90 µmol/m2/day, respectively. This internal recycling of ammonium and phosphate from fine-grained, organic-rich sediments that comprise at least 10% of the sediments throughout the northern lagoon total 300 metric tons/yr and 50 metric tons/yr, respectively, and were greater than external inputs to this system. Ammonium fluxes varied spatially in response to physical and chemical differences in sediment composition. Seasonal and experimental changes in temperature resulted in a >50% differences in fluxes of ammonium and phosphate. High fluxes of dissolved sulfide supported dense mats of sulfur-oxidizing bacteria that provided stability to an otherwise unconsolidated fluff layer; this negative feedback loop reduced the net flux of nitrogen and phosphorus into the overlying water.

  13. Electrocatalytic processing of renewable biomass-derived compounds for production of chemicals, fuels and electricity

    NASA Astrophysics Data System (ADS)

    Xin, Le

    The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with renewable carbon from biomass as possible, innovative R&D activities must strive to enhance the current biorefinery process and secure our energy future. Much of my Ph.D. research effort is centered on the study of electrocatalytic conversion of biomass-derived compounds to produce value-added chemicals, biofuels and electrical energy on model electrocatalysts in AEM/PEM-based continuous flow electrolysis cell and fuel cell reactors. High electricity generation performance was obtained when glycerol or crude glycerol was employed as fuels in AEMFCs. The study on selective electrocatalytic oxidation of glycerol shows an electrode potential-regulated product distribution where tartronate and mesoxalate can be selectively produced with electrode potential switch. This finding then led to the development of AEMFCs with selective production of valuable tartronate or mesoxalate with high selectivity and yield and cogeneration of electricity. Reaction mechanisms of electrocatalytic oxidation of ethylene glycol and 1,2-propanediol were further elucidated by means of an on-line sample collection technique and DFT modeling. Besides electro-oxidation of biorenewable alcohols to chemicals and electricity, electrocatalytic reduction of keto acids (e.g. levulinic acid) was also studied for upgrading biomass-based feedstock to biofuels while

  14. Chemical Speciation and Health Risk Assessment of Fine Particulate Bound Trace Metals Emitted from Ota Industrial Estate, Nigeria

    NASA Astrophysics Data System (ADS)

    Anake, Winifred U.; Ana, Godson R. E. E.; Williams, Akan B.; Fred-Ahmadu, Omowunmi H.; Benson, Nsikak U.

    2017-05-01

    In this study carcinogenic and non-carcinogenic health risk due to exposure to PM2.5-bound trace metals from an industrial area in Southwestern Nigeria was estimated. A four-step chemical sequential extraction procedure was employed for the chemical extraction of arsenic (As), cadmium (Cd), chromium (Cr) copper (Cu), manganese (Mn), nickel (Ni), and zinc (Zn). Samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Results reveal Cr and Cu as the most dominant exchangeable fraction metals, indicating possibility of their being readily soluble once PM2.5 is inhaled. Cd and Cr record the highest bioavailability index of 0.7. The cumulative lifetime cancer risks due to inhalation exposure for adults (4.25×10-2), children 1-6 years old (4.87×10-3), and children 6-18 years old (1.46×10-2) were found above Environmental Protection Agency’s acceptable range of 1×10-6 to 1×10-4. The hazard index values for all studied trace metals suggest significant potential for non-carcinogenic health risks to adults and children. The choice of chemical speciation as an essential tool in facilitating a better predictive insight on metal bioavailability and toxicity for immediate remediation action has been highlighted.

  15. On the use of LUDI to search the Fine Chemicals Directory for ligands of proteins of known three-dimensional structure

    NASA Astrophysics Data System (ADS)

    Böhm, Hans-Joachim

    1994-10-01

    It is shown that the computer program LUDI can be used to search large databases of three-dimensional structures for putative ligands of proteins with known 3D structure. As an example, a subset of ≈30 000 small molecules (with less than 40 atoms and 0-2 rotatable bonds) from the Fine Chemicals Directory has been used in the search for possible novel ligands for four different proteins (trypsin, streptavidin, purine nucleoside phosphorylase and HIV protease). For trypsin and streptavidin, known ligands or substructures of known ligands are retrieved as top-scoring hits. In addition, a number of new interesting structures are found in all considered cases. Therefore, the method holds promise to retrieve automatically protein ligands from a 3D database if the 3D structure of the target protein is known.

  16. Treeline advances and associated shifts in the ground vegetation alter fine root dynamics and mycelia production in the South and Polar Urals.

    PubMed

    Solly, Emily F; Djukic, Ika; Moiseev, Pavel A; Andreyashkina, Nelly I; Devi, Nadezhda M; Göransson, Hans; Mazepa, Valeriy S; Shiyatov, Stepan G; Trubina, Marina R; Schweingruber, Fritz H; Wilmking, Martin; Hagedorn, Frank

    2017-02-01

    Climate warming is shifting the elevational boundary between forests and tundra upwards, but the related belowground responses are poorly understood. In the pristine South and Polar Urals with shifts of the treeline ecotone documented by historical photographs, we investigated fine root dynamics and production of extramatrical mycorrhizal mycelia (EMM) along four elevational transects reaching from the closed forest to the treeless tundra. In addition, we analysed elevational differences in climate and vegetation structure, and excavated trees to estimate related changes in the partitioning between below- and aboveground biomass. Fine root biomass of trees (<2 mm) increased by 13-79% with elevation, paralleled by a 35-72% increase in ground vegetation fine roots from the closed forest to the tundra. During the first year of decomposition, mass loss of fine root litter from different vegetation types was greater at lower elevations in the forest-tundra ecotone. The ratio between fine roots of trees and stem biomass largely increased with elevation in both regions, but these increases were not accompanied by a distinct production of EMM. Production of EMM, however, increased with the presence of ectomycorrhizal trees at the transition from the tundra to the forest. Our results imply that the recorded upward expansion of forest into former tundra in the Ural Mountains by 4-8 m per decade is decreasing the partitioning of plant biomass to fine roots. They further suggest that climate-driven forest advances will alter EMM production rates with potential feedbacks on soil carbon and nutrient cycling in these ecosystems.

  17. Chemical pretreatment of lignocellulosic agroindustrial waste for methane production.

    PubMed

    Pellera, Frantseska-Maria; Gidarakos, Evangelos

    2017-04-26

    This study investigates the effect of different chemical pretreatments on the solubilization and the degradability of different solid agroindustrial waste, namely winery waste, cotton gin waste, olive pomace and juice industry waste. Eight different reagents were investigated, i.e. sodium hydroxide (NaOH), sodium bicarbonate (NaHCO3), sodium chloride (NaCl), citric acid (H3Cit), acetic acid (AcOH), hydrogen peroxide (H2O2), acetone (Me2CO) and ethanol (EtOH), under three condition sets resulting in treatments of varying intensity, depending on process duration, reagent dosage and temperature. Results indicated that chemical pretreatment under more severe conditions is more effective on the solubilization of lignocellulosic substrates, such as those of the present study and among the investigated reagents, H3Cit, H2O2 and EtOH appeared to be the most effective to this regard. At the same time, although chemical pretreatment in general did not improve the methane potential of the substrates, moderate to high severity conditions were found to generally be the most satisfactory in terms of methane production from pretreated materials. In fact, moderate severity treatments using EtOH for winery waste, H3Cit for olive pomace and H2O2 for juice industry waste and a high severity treatment with EtOH for cotton gin waste, resulted in maximum specific methane yield values. Ultimately, the impact of pretreatment parameters on the different substrates seems to be dependent on their characteristics, in combination with the specific mode of action of each reagent. The overall energy balance of such a system could probably be improved by using lower operating powers and higher solid to liquid ratios. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Biosynthesis and Chemical Synthesis of Presilphiperfolanol Natural Products**

    PubMed Central

    Hong, Allen Y.

    2015-01-01

    Presilphiperfolanols constitute a family of biosynthetically important sesquiterpenes that can rearrange to diverse sesquiterpenoid skeletons. While the origin of these natural products can be traced to simple linear terpene precursors, the details of the enzymatic cyclization mechanism that form the stereochemically dense tricyclic skeleton have required extensive biochemical, computational, and synthetic investigation. Parallel efforts to prepare the unique and intriguing structures of these compounds by total synthesis have also inspired novel strategies, resulting in two synthetic approaches and two completed syntheses. While the biosynthesis and chemical synthesis studies performed to date have provided much insight into the role and properties of these molecules, new questions regarding the biosynthesis of newer members of the family and subtle details of the cyclization mechanism have yet to be explored. PMID:24771653

  19. Analysis for chemical agent breakdown products: Avoiding IMPA false positives

    SciTech Connect

    Ives, K.M.; Markowitz, V.

    1996-12-31

    Cleanup of DOD sites where chemical warfare agents have been used or stored presents a number of unique problems. Isopropylmethylphosphonic Acid (IMPA), a degradation product of Sarin (GB), is one important contaminant to be monitored at many such sites. IMPA has historically been determined by Army Environmental Center (AEC) method UT02, an ion chromatography method. This method is prone to serious interference problems which can lead an inexperienced analyst to report false positive results. A study of interferences present in groundwater samples taken from a US military installation was undertaken. The interference problems were identified, and techniques were developed which minimize the problem in most samples. These techniques have been used by the authors in several large studies at DOD sites, and have virtually eliminated false positive problems.

  20. Chemical changes associated with lotus and water lily natto production

    NASA Astrophysics Data System (ADS)

    Lestari, S. D.; Fatimah, N.; Nopianti, R.

    2017-04-01

    Natto is a traditional Japanese food made by fermenting whole soybean seeds with pure culture of Bacillus subtilis subsp. natto. The purpose of this study was to investigate the suitability of lotus (Nelumbo nucifera) and water lily (Nymphaea stellata) seeds as the raw materials for natto production. Chemical (proximate, amino acids and minerals) changes were observed on raw, steamed and fermented seeds. Proximate compositions of all samples were calculated in both wet basis and dry basis. In wet basis calculation, steaming and fermentation tended to lower the carbohydrates, ashes, fats and protein content which were attributed to the increase of moisture. The total amino acid, iron and magnesium contents of raw lotus seeds were 24.29%, 5.08 mg 100g-1 and 174.23 mg 100g-1 dry matter, respectively. After a 24h-fermentation at 40°C, the total amino acids decreased while iron and magnesium contents increased significantly reaching, in respective order, 9.9 mg 100g-1 and 411.36 mg 100g-1 dry matter. Changes in chemical composition after fermentation were more pronounced in lotus seeds than water lily seeds indicating that their nutrient composition were more suitable to support Bacillus subtilis growth.

  1. Production and physico-chemical characterisation of nanoparticles.

    PubMed

    Schulze Isfort, C; Rochnia, M

    2009-05-08

    Synthetic nanoscaled metal oxides are mainly produced by pyrogenic decomposition of precursors in the gas phase using a hot-wall or plasma reactor. Due to their low production rate and limited scalability, these processes are of minor technical relevance in manufacturing commercial quantities of nanoparticles. The most common and by far the most important industrial process is flame hydrolysis. In this process, a gaseous mixture of a metal chloride precursor, hydrogen and air is introduced in a closed and continuously operated flame reactor. The general mechanism of formation and growth of particles (e.g. silica) occurring in the flame is dominated by nucleation, coalescence (sintering) and coagulation (collision) of primary particles forming aggregated structures. The term 'aggregate' describes clusters of particles held together by strong chemical bonds. Agglomerates, however, are defined as loose accumulations of particles held together by hydrogen bonds for example. Although, a variety of physico-chemical methods exist to characterise pyrogenic oxides, the most important ones are analysis of the specific surface area by the so-called BET method, determination of the aggregate size by transmission electron microscopy (TEM) and characterisation of the phase composition by means of X-ray analysis.

  2. Production and Chemical Analysis of Cometary Ice Tholins

    NASA Astrophysics Data System (ADS)

    McDonald, Gene D.; Whited, Linda J.; DeRuiter, Cynthia; Khare, Bishun N.; Patnaik, Archita; Sagan, Carl

    1996-07-01

    Organic heteropolymers that we call here ice tholin II have been produced by plasma discharge irradiation of water/methanol/carbon dioxide/ethane cocondensed ices in a rough simulation of cometary chemistry. The radiation yield of these organic heteropolymers is approximately 10-26g/eV. Intermediate products including polyalcohols, ethers, esters, carboxylic acids, and hydrocarbons are also produced. No detectable polyoxymethylene is generated in this experiment. Preliminary chemical analyses of ice tholin using spectroscopic and chromatographic techniques lead to the conclusion that ice tholin contains a significant degree of polyalcohol functionality, as well as aliphatic hydrocarbon groups and carbonyl-containing groups such as ketones and esters. Ice tholin II shows some spectroscopic similarities to 1:6 ethane/water ice tholin (ice tholin I), but overall the two are chemically distinct. Ice tholins may be difficult to detect in comets due to their low volatility, but nevertheless may have been delivered to the early Earth by cometary impacts and interplanetary dust particles. These polyalcohol-containing molecules would then have been available to participate in prebiotic chemistry, such as the synthesis of acyclic nucleic acid analogues which have been suggested as the first biomacromolecules

  3. Production of Seamless Superconducting Radio Frequency Cavities from Ultra-fine Grained Niobium, Phase II Final Report

    SciTech Connect

    Roy Crooks, Ph.D., P.E.

    2009-10-31

    The positron and electron linacs of the International Linear Collider (ILC) will require over 14,000, nine-cell, one meter length, superconducting radio frequency (SRF) cavities [ILC Reference Design Report, 2007]. Manufacturing on this scale will benefit from more efficient fabrication methods. The current methods of fabricating SRF cavities involve deep drawing of the halves of each of the elliptical cells and joining them by high-vacuum, electron beam welding, with at least 19 circumferential welds per cavity. The welding is costly and has undesirable effects on the cavity surfaces, including grain-scale surface roughening at the weld seams. Hydroforming of seamless tubes avoids welding, but hydroforming of coarse-grained seamless tubes results in strain-induced surface roughening. Surface roughness limits accelerating fields, because asperities prematurely exceed the critical magnetic field and become normal conducting. This project explored the technical and economic feasibility of an improved processing method for seamless tubes for hydroforming. Severe deformation of bulk material was first used to produce a fine structure, followed by extrusion and flow-forming methods of tube making. Extrusion of the randomly oriented, fine-grained bulk material proceeded under largely steady-state conditions, and resulted in a uniform structure, which was found to be finer and more crystallographically random than standard (high purity) RRR niobium sheet metal. A 165 mm diameter billet of RRR grade niobium was processed into five, 150 mm I.D. tubes, each over 1.8 m in length, to meet the dimensions used by the DESY ILC hydroforming machine. Mechanical properties met specifications. Costs of prototype tube production were approximately twice the price of RRR niobium sheet, and are expected to be comparable with economies of scale. Hydroforming and superconducting testing will be pursued in subsequent collaborations with DESY and Fermilab. SRF Cavities are used to construct

  4. Chemical Reaction and Flow Modeling in Fullerene and Nanotube Production

    NASA Technical Reports Server (NTRS)

    Scott, Carl D.; Farhat, Samir; Greendyke, Robert B.

    2004-01-01

    The development of processes to produce fullerenes and carbon nanotubes has largely been empirical. Fullerenes were first discovered in the soot produced by laser ablation of graphite [1]and then in the soot of electric arc evaporated carbon. Techniques and conditions for producing larger and larger quantities of fullerenes depended mainly on trial and error empirical variations of these processes, with attempts to scale them up by using larger electrodes and targets and higher power. Various concepts of how fullerenes and carbon nanotubes were formed were put forth, but very little was done based on chemical kinetics of the reactions. This was mainly due to the complex mixture of species and complex nature of conditions in the reactors. Temperatures in the reactors varied from several thousand degrees Kelvin down to near room temperature. There are hundreds of species possible, ranging from atomic carbon to large clusters of carbonaceous soot, and metallic catalyst atoms to metal clusters, to complexes of metals and carbon. Most of the chemical kinetics of the reactions and the thermodynamic properties of clusters and complexes have only been approximated. In addition, flow conditions in the reactors are transient or unsteady, and three dimensional, with steep spatial gradients of temperature and species concentrations. All these factors make computational simulations of reactors very complex and challenging. This article addresses the development of the chemical reaction involved in fullerene production and extends this to production of carbon nanotubes by the laser ablation/oven process and by the electric arc evaporation process. In addition, the high-pressure carbon monoxide (HiPco) process is discussed. The article is in several parts. The first one addresses the thermochemical aspects of modeling; and considers the development of chemical rate equations, estimates of reaction rates, and thermodynamic properties where they are available. The second part

  5. Chemical constituents of fine particulate air pollution and pulmonary function in healthy adults: the Healthy Volunteer Natural Relocation study.

    PubMed

    Wu, Shaowei; Deng, Furong; Hao, Yu; Shima, Masayuki; Wang, Xin; Zheng, Chanjuan; Wei, Hongying; Lv, Haibo; Lu, Xiuling; Huang, Jing; Qin, Yu; Guo, Xinbiao

    2013-09-15

    The study examined the associations of 32 chemical constituents of particulate matter with an aerodynamic diameter ≤2.5 μm (PM₂.₅) with pulmonary function in a panel of 21 college students. Study subjects relocated from a suburban area to an urban area with changing ambient air pollution levels and contents in Beijing, China, and provided daily morning/evening peak expiratory flow (PEF) and forced expiratory volume in 1s (FEV₂₁) measurements over 6 months in three study periods. There were significant reductions in evening PEF and morning/evening FEV₂₁ associated with various air pollutants and PM₂.₅ constituents. Four PM₂.₅ constituents (copper, cadmium, arsenic and stannum) were found to be most consistently associated with the reductions in these pulmonary function measures. These findings provide clues for the respiratory effects of specific particulate chemical constituents in the context of urban air pollution. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. [Preventive measures against health damage due to chemicals in household products].

    PubMed

    Kaniwa, Masa-aki

    2010-01-01

    Chemicals in household products have been paid much attention as the main cause of health damage in consumers, such as allergic contact dermatitis. Preventive measures against health damage due to chemicals in fabrics, plastics and rubber products for household use, are reviewed, focusing on 1) the incidence of health damage due to household products, 2) causative product-chemical investigation, and 3) case studies on skin damage.

  7. Development of a Consumer Product Ingredient Database for Chemical ExposureScreening and Prioritization

    EPA Science Inventory

    Consumer products are a primary source of chemical exposures, yet little structured information is available on the chemical ingredients of these products and the concentrations at which ingredients are present. To address this data gap, we created a database of chemicals in cons...

  8. Human exposure modeling in a life cycle framework for chemicals and products

    EPA Science Inventory

    A chemical enters into commerce to serve a specific function in a product or process. This decision triggers both the manufacture of the chemical and its potential release over the life cycle of the product. Efficiently evaluating chemical safety and sustainability requires combi...

  9. Development of a Consumer Product Ingredient Database for Chemical ExposureScreening and Prioritization

    EPA Science Inventory

    Consumer products are a primary source of chemical exposures, yet little structured information is available on the chemical ingredients of these products and the concentrations at which ingredients are present. To address this data gap, we created a database of chemicals in cons...

  10. Human exposure modeling in a life cycle framework for chemicals and products

    EPA Science Inventory

    A chemical enters into commerce to serve a specific function in a product or process. This decision triggers both the manufacture of the chemical and its potential release over the life cycle of the product. Efficiently evaluating chemical safety and sustainability requires combi...

  11. Modeling of the chemical composition of fine particulate matter: Development and performance assessment of EASYWRF-Chem

    NASA Astrophysics Data System (ADS)

    Mendez, M.; Lebègue, P.; Visez, N.; Fèvre-Nollet, V.; Crenn, V.; Riffault, V.; Petitprez, D.

    2016-03-01

    The European emission Adaptation SYstem for the WRF-Chem model (EASYWRF-Chem) has been developed to generate chemical information supporting the WRF-Chem requirements from any emission inventory based on the CORINAIR methodology. Using RADM2 and RACM2 mechanisms, "emission species" are converted into "model species" thanks to the SAPRC methodology for gas phase pollutant and the PM10 and PM2.5 fractions. Furthermore, by adapting US EPA PM2.5 profiles, the processing of aerosol chemical speciation profiles separates the unspeciated PM2.5 emission into five chemical families: sulfates, nitrates, elemental carbon, organic aerosol and unspeciated aerosol. The evaluation of the model has been performed by separately comparing model outcomes with (i) meteorological measurements; (ii) NO2, O3, PM10 and PM2.5 mass concentrations from the regional air quality monitoring network; (iii) hourly-resolved data from four field campaign measurements, in winter and in summer, on two sites in the French northern region. In the latter, a High Resolution - Time of Flight - Aerosol Mass Spectrometer (HR-ToF-AMS) provided non-refractory PM1 concentrations of sulfate, nitrate and ammonium ions as well as organic matter (OM), while an aethalometer provided black carbon (BC) concentrations in the PM2.5 fraction. Meteorological data (temperature, wind, relative humidity) are well simulated for all the time series data except for specific events as wind direction changes or rainfall. For particulate matter, results are presented by considering firstly the total mass concentration of PM2.5 and PM10. EASYWRF-Chem simulations overestimated the PM10 mass concentrations by + 22% and + 4% for summer and winter periods respectively, whereas for the finer PM2.5 fraction, mass concentrations were overestimated by + 20% in summer and underestimated by - 13% in winter. Simulated sulfate concentrations were underestimated and nitrate concentrations were overestimated but hourly variations were well

  12. Synthetic and systems biology for microbial production of commodity chemicals

    DOE PAGES

    Chubukov, Victor; Mukhopadhyay, Aindrila; Petzold, Christopher J.; ...

    2016-04-07

    The combination of synthetic and systems biology is a powerful framework to study fundamental questions in biology and produce chemicals of immediate practical application such as biofuels, polymers, or therapeutics. However, we cannot yet engineer biological systems as easily and precisely as we engineer physical systems. In this review, we describe the path from the choice of target molecule to scaling production up to commercial volumes. We present and explain some of the current challenges and gaps in our knowledge that must be overcome in order to bring our bioengineering capabilities to the level of other engineering disciplines. Challenges startmore » at molecule selection, where a difficult balance between economic potential and biological feasibility must be struck. Pathway design and construction have recently been revolutionized by next-generation sequencing and exponentially improving DNA synthesis capabilities. Although pathway optimization can be significantly aided by enzyme expression characterization through proteomics, choosing optimal relative protein expression levels for maximum production is still the subject of heuristic, non-systematic approaches. Toxic metabolic intermediates and proteins can significantly affect production, and dynamic pathway regulation emerges as a powerful but yet immature tool to prevent it. Host engineering arises as a much needed complement to pathway engineering for high bioproduct yields; and systems biology approaches such as stoichiometric modeling or growth coupling strategies are required. A final, and often underestimated, challenge is the successful scale up of processes to commercial volumes. Sustained efforts in improving reproducibility and predictability are needed for further development of bioengineering.« less

  13. [Impact of maternal genetic effect on genetic parameter estimation of production traits for Qinghai fine-wool sheep].

    PubMed

    Wang, Peng-Yu; Guanque, Zha-Xi; Qi, Quan-Qing; De, Mao; Zhang, Wen-Guang; Li, Jin-Quan

    2012-05-01

    The maternal genetic effects on estimating genetic parameters for growth traits and wool traits of Qinghai fine-wool sheep were investigated.The genetic parameters for production traits of Qinghai fine-wool sheep were estimated by average information restricted maximum likelihood (AIREML) with different animal models, and the differences between different animal models were tested by likelihood ratio test. Fixed effects, direct genetic effects, and residual effects were included all models; and random effects were individual permanence environmental effects, maternal genetic effects, and maternal permanence environmental effects. The six models differ in the way of considering random effects: in model 1 individual permanence environmental effects, maternal genetic effects, and maternal permanence environmental effects were not contained; in model 2 maternal permanence environmental effects were included; in model 3 maternal genetic effects were included; in model 4 both maternal genetic effects and maternal permanence environmental effects were include; in model 5 both individual permanence environmental effects and maternal genetic effects were contained;in model 6 all random effects were contained. The direct heritabilities were 0.1896~0.3781, 0.2537~0.2890, 0.2244~0.3225, 0.2205~0.3983, 0.1218~0.1490, 0.0983~0.4802, and 0.1170~0.1311 for birth weight, weaning weight, yearling weight, hogget weight,greasy fleece weight, fiber diameter, and staple length,respectively. Compared with model 1, model 3 was-significant(P<0.01) for birth weight and weaning weight, other models were not significant (P>0.05)for Yearling weight, Hogget weight; and paralleled with model 6, both model 4 and model 5 were significant(P<0.01) for fiber diameter,model 4 was significant(P<0.05) for staple length, and other models were not significant(P>0.05) for greasy fleece weight by likelihood ratio test.The maternal effects were important determinants of estimated the genetic parameters for

  14. Near-road sampling of PM2. 5, BC, and fine-particle chemical components in Kathmandu Valley, Nepal

    NASA Astrophysics Data System (ADS)

    Shakya, Kabindra M.; Rupakheti, Maheswar; Shahi, Anima; Maskey, Rejina; Pradhan, Bidya; Panday, Arnico; Puppala, Siva P.; Lawrence, Mark; Peltier, Richard E.

    2017-06-01

    Semicontinuous PM2. 5 and black carbon (BC) concentrations, and 24 h integrated PM2. 5 filter samples were collected near roadways in the Kathmandu Valley, Nepal. Instruments were carried by a group of volunteer traffic police officers in the vicinity of six major roadway intersections in the Kathmandu Valley across two sampling periods in 2014. Daily PM2. 5 filter samples were analyzed for water-soluble inorganic ions, elemental carbon (EC) and organic carbon (OC), and 24 elements. Mean PM2. 5 and BC concentrations were 124.76 µg m-3 and 16.74 µgC m-3 during the drier spring sampling period, and 45.92 µg m-3 and 13.46 µgC m-3 during monsoonal sampling. Despite the lower monsoonal PM2. 5 concentrations, BC and several elements were not significantly lower during the monsoon, which indicates an important contribution of vehicle-related emissions throughout both seasons in this region. During the monsoon, there was an enhanced contribution of chemical species (elements and water-soluble inorganic ions), except secondary inorganic ions, and BC to PM2. 5 (crustal elements: 19 %; heavy metals: 5 %; and BC: 39 %) compared to those in spring (crustal elements: 9 %; heavy metals: 1 %; and BC: 18 %). Silica, calcium, aluminum, and iron were the most abundant elements during both spring and the monsoon, with total concentrations of 12.13 and 8.85 µg m-3, respectively. PM2. 5 and BC showed less spatial variation compared to that for individual chemical species.

  15. Chemical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1 to 3.

    PubMed

    Kinsey, J S; Hays, M D; Dong, Y; Williams, D C; Logan, R

    2011-04-15

    This paper addresses the need for detailed chemical information on the fine particulate matter (PM) generated by commercial aviation engines. The exhaust plumes of seven turbofan engine models were sampled as part of the three test campaigns of the Aircraft Particle Emissions eXperiment (APEX). In these experiments, continuous measurements of black carbon (BC) and particle surface-bound polycyclic aromatic compounds (PAHs) were conducted. In addition, time-integrated sampling was performed for bulk elemental composition, water-soluble ions, organic and elemental carbon (OC and EC), and trace semivolatile organic compounds (SVOCs). The continuous BC and PAH monitoring showed a characteristic U-shaped curve of the emission index (EI or mass of pollutant/mass of fuel burned) vs fuel flow for the turbofan engines tested. The time-integrated EIs for both elemental composition and water-soluble ions were heavily dominated by sulfur and SO(4)(2-), respectively, with a ∼2.4% median conversion of fuel S(IV) to particle S(VI). The corrected OC and EC emission indices obtained in this study ranged from 37 to 83 mg/kg and 21 to 275 mg/kg, respectively, with the EC/OC ratio ranging from ∼0.3 to 7 depending on engine type and test conditions. Finally, the particle SVOC EIs varied by as much as 2 orders of magnitude with distinct variations in chemical composition observed for different engine types and operating conditions.

  16. Eight-year (2007-2014) trends in ambient fine particulate matter (PM2.5) and its chemical components in the Capital Region of Alberta, Canada.

    PubMed

    Bari, Md Aynul; Kindzierski, Warren B

    2016-05-01

    Currently there have been questions about ambient fine particulate matter (PM2.5) levels in the Capital Region of Alberta, Canada. An investigation of temporal trends in PM2.5 and its chemical components was undertaken in the City of Edmonton within the Capital Region over an 8-year period (2007-2014). A non-parametric trend detection method was adopted to characterize trends in ambient concentrations. No statistically significant change was observed for ambient PM2.5 concentrations during 2007-2014, while significant decreasing trends were found for organic carbon, elemental carbon, oxalate, barium, lead and cadmium. A statistically significant increasing trend was observed for sodium chloride indicating an increase of de-icing salt contribution for winter road maintenance in recent years. Concentrations of potassium ion and zinc exhibited strong and significant seasonal variability with higher concentrations in winter than in summer likely reflecting wood smoke origins more than other potential sources in Edmonton and the surrounding region. No statistically significant changes were observed for all other chemical components examined. Notwithstanding robust population growth that has occurred in Edmonton, these findings reveal that particulate air quality and corresponding trace elements in Edmonton's air has been unchanged or improved over the investigated period (2007-2014). Longer-term air quality monitoring at least over several decades is needed to establish whether trends reported here are actually occurring. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions

    NASA Astrophysics Data System (ADS)

    Sciare, J.; D'Argouges, O.; Sarda-Estève, R.; Gaimoz, C.; Gros, V.; Zhang, Q. J.; Beekmann, M.; Sanchez, O.

    2010-07-01

    Hourly concentrations of inorganic salts (ions) and carbonaceous material in fine aerosols (aerodynamic diameter, A.D.<2.5 μm) have been determined experimentally from fast measurements performed for a 3-week period in spring 2007 in Paris (France). The sum of these two chemical components (ions and carbonaceous aerosols) has shown to account for most of the fine aerosol mass (PM2.5). This time-resolved dataset allowed investigating the factors controlling the levels of PM2.5 in Paris and showed that polluted periods with PM2.5<15 μg/m3 were characterized by air masses of continental (North-Western Europe) origin and chemical composition made by 75% of ions. By contrast, periods with clean marine air masses have shown the lowest PM2.5 concentrations (typically of about 10 μg/m3); carbonaceous aerosols contributing for most of this mass (typically 75%). In order to better discriminate between regional and continental contributions to the observed chemical composition and concentrations of PM2.5 over Paris, a comparative study was performed between this time-resolved dataset and the outputs of a chemistry transport model (CHIMERE), showing a relatively good capability of the model to reproduce the time-limited intense maxima observed in the field for PM2.5 and ion species. Different model scenarios were then investigated switching off regional and European (North-Western and Central) emissions. Results of these scenarios have clearly shown that most of the ions observed over Paris during polluted periods, were either transported or formed in-situ from gas precursors transported from Northern Europe. By opposite, long-range transport from Europe appeared to poorly contribute to the levels of carbonaceous aerosols observed over Paris. The model failed to properly account for the concentration levels and variability of secondary organic aerosols (SOA) determined experimentally by the EC-tracer method. The abundance of SOA (relatively to organic aerosol, OA) was as

  18. Comparison between simulated and observed chemical composition of fine aerosols in Paris (France) during springtime: contribution of regional versus continental emissions

    NASA Astrophysics Data System (ADS)

    Sciare, J.; D'Argouges, O.; Zhang, Q. J.; Sarda-Estève, R.; Gaimoz, C.; Gros, V.; Beekmann, M.; Sanchez, O.

    2010-12-01

    Hourly concentrations of inorganic salts (ions) and carbonaceous material in fine aerosols (aerodynamic diameter, A.D. <2.5 μm) have been determined experimentally from fast measurements performed for a 3-week period in spring 2007 in Paris (France). The sum of these two chemical components (ions and carbonaceous aerosols) has shown to account for most of the fine aerosol mass (PM2.5). This time-resolved dataset allowed investigating the factors controlling the levels of PM2.5 in Paris and showed that polluted periods with PM2.5 > 15 μg m-3 were characterized by air masses of continental (North-Western Europe) origin and chemical composition made by 75% of ions. By contrast, periods with clean marine air masses have shown the lowest PM2.5 concentrations (typically of about 10 μg m-3); carbonaceous aerosols contributing for most of this mass (typically 75%). In order to better discriminate between local and continental contributions to the observed chemical composition and concentrations of PM2.5 over Paris, a comparative study was performed between this time-resolved dataset and the outputs of a chemistry transport model (CHIMERE), showing a relatively good capability of the model to reproduce the time-limited intense maxima observed in the field for PM2.5 and ion species. Different model scenarios were then investigated switching off local and European (North-Western and Central) emissions. Results of these scenarios have clearly shown that most of the ions observed over Paris during polluted periods, were either transported or formed in-situ from gas precursors transported from Northern Europe. On the opposite, long-range transport from Europe appeared to weakly contribute to the levels of carbonaceous aerosols observed over Paris. The model failed to properly account for the concentration levels and variability of secondary organic aerosols (SOA) determined experimentally by the EC-tracer method. The abundance of SOA (relatively to organic aerosol, OA) was as

  19. Identifying new persistent and bioaccumulative organics among chemicals in commerce. III: byproducts, impurities, and transformation products.

    PubMed

    Howard, Philip H; Muir, Derek C G

    2013-05-21

    The goal of this series of studies was to identify commercial chemicals that might be persistent and bioaccumulative (PB) and that were not being considered in current wastewater and aquatic environmental measurement programs. In this study, we focus on chemicals that are not on commercial chemical lists such as U.S. EPA's Inventory Update Rule but may be found as byproducts or impurities in commercial chemicals or are likely transformation products from commercial chemical use. We evaluated the 610 chemicals from our earlier publication as well as high production volume chemicals and identified 320 chemicals (39 byproducts and impurities, and 281 transformation products) that could be potential PB chemicals. Four examples are discussed in detail; these chemicals had a fair amount of information on the commercial synthesis and byproducts and impurities that might be found in the commercial product. Unfortunately for many of the 610 chemicals, as well as the transformation products, little or no information was available. Use of computer-aided software to predict the transformation pathways in combination with the biodegradation rules of thumb and some basic organic chemistry has allowed 281 potential PB transformation products to be suggested for some of the 610 commercial chemicals; more PB transformation products were not selected since microbial degradation often results in less persistent and less bioaccumulative metabolites.

  20. Fine Particle Sources and Cardiorespiratory Morbidity: An Application of Chemical Mass Balance and Factor Analytical Source-Apportionment Methods

    PubMed Central

    Sarnat, Jeremy A.; Marmur, Amit; Klein, Mitchel; Kim, Eugene; Russell, Armistead G.; Sarnat, Stefanie E.; Mulholland, James A.; Hopke, Philip K.; Tolbert, Paige E.

    2008-01-01

    Background Interest in the health effects of particulate matter (PM) has focused on identifying sources of PM, including biomass burning, power plants, and gasoline and diesel emissions that may be associated with adverse health risks. Few epidemiologic studies, however, have included source-apportionment estimates in their examinations of PM health effects. We analyzed a time-series of chemically speciated PM measurements in Atlanta, Georgia, and conducted an epidemiologic analysis using data from three distinct source-apportionment methods. Objective The key objective of this analysis was to compare epidemiologic findings generated using both factor analysis and mass balance source-apportionment methods. Methods We analyzed data collected between November 1998 and December 2002 using positive-matrix factorization (PMF), modified chemical mass balance (CMB-LGO), and a tracer approach. Emergency department (ED) visits for a combined cardiovascular (CVD) and respiratory disease (RD) group were assessed as end points. We estimated the risk ratio (RR) associated with same day PM concentrations using Poisson generalized linear models. Results There were significant, positive associations between same-day PM2.5 (PM with aero-dynamic diameter ≤ 2.5 μm) concentrations attributed to mobile sources (RR range, 1.018–1.025) and biomass combustion, primarily prescribed forest burning and residential wood combustion, (RR range, 1.024–1.033) source categories and CVD-related ED visits. Associations between the source categories and RD visits were not significant for all models except sulfate-rich secondary PM2.5 (RR range, 1.012–1.020). Generally, the epidemiologic results were robust to the selection of source-apportionment method, with strong agreement between the RR estimates from the PMF and CMB-LGO models, as well as with results from models using single-species tracers as surrogates of the source-apportioned PM2.5 values. Conclusions Despite differences among the

  1. Bio-based production of C2-C6 platform chemicals.

    PubMed

    Jang, Yu-Sin; Kim, Byoungjin; Shin, Jae Ho; Choi, Yong Jun; Choi, Sol; Song, Chan Woo; Lee, Joungmin; Park, Hye Gwon; Lee, Sang Yup

    2012-10-01

    Platform chemicals composed of 2-6 carbons derived from fossil resources are used as important precursors for making a variety of chemicals and materials, including solvents, fuels, polymers, pharmaceuticals, perfumes, and foods. Due to concerns regarding our environment and the limited nature of fossil resources, however, increasing interest has focused on the development of sustainable technologies for producing these platform chemicals from renewable resources. The techniques and strategies for developing microbial strains for chemicals production have advanced rapidly, and it is becoming feasible to develop microbes for producing additional types of chemicals, including non-natural molecules. In this study, we review the current status of the bio-based production of major C2-C6 platform chemicals, focusing on the microbial production of platform chemicals that have been used for the production of chemical intermediates, building block compounds, and polymers. Copyright © 2012 Wiley Periodicals, Inc.

  2. Fast changes in chemical composition and size distribution of fine particles during the near-field transport of industrial plumes.

    PubMed

    Marris, Hélène; Deboudt, Karine; Augustin, Patrick; Flament, Pascal; Blond, François; Fiani, Emmanuel; Fourmentin, Marc; Delbarre, Hervé

    2012-06-15

    Aerosol sampling was performed inside the chimneys and in the close environment of a FeMn alloys manufacturing plant. The number size distributions show a higher abundance of ultrafine aerosols (10-100 nm) inside the plume than upwind of the plant, indicating the emissions of nanoparticles by the industrial process. Individual analysis of particles collected inside the plume shows a high proportion of metal bearing particles (Mn-/Fe-) consisting essentially of internally mixed aluminosilicate and metallic compounds. These particles evolve rapidly (in a few minutes) after emission by adsorption of VOC gas and sulfuric acid emitted by the plant but also by agglomeration with pre-existing particles. At the moment, municipalities require a monitoring of industrial emissions inside the chimneys from manufacturers. However those measures are insufficient to report such rapid changes in chemical composition and thus to evaluate the real impact of industrial plumes in the close environment of plants (when those particles leave the industrial site). Consequently, environmental authorities will have to consider such fast evolutions and then to adapt future regulations on air pollution sources. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Community-level spatial heterogeneity of chemical constituent levels of fine particulates and implications for epidemiological research

    PubMed Central

    Bell, Michelle L.; Ebisu, Keita; Peng, Roger D.

    2011-01-01

    Studies of the health impacts of airborne particulates’ chemical constituents typically assume spatial homogeneity and estimate exposure from ambient monitors. However, factors such as local sources may cause spatially heterogeneous pollution levels. This work examines the degree to which constituent levels vary within communities and whether exposure misclassification is introduced by spatial homogeneity assumptions. Analysis considered PM2.5 elemental carbon (EC), organic carbon matter, ammonium, sulfate, nitrate, silicon, and sodium ion (Na+) for the United States, 1999–2007. Pearson correlations and coefficients of divergence were calculated and compared to distances among monitors. Linear modeling related correlations to distance between monitors, long-term constituent levels, and population density. Spatial heterogeneity was present for all constituents, yet lower for ammonium, sulfate, and nitrate. Lower correlations were associated with higher distance between monitors, especially for nitrate and sulfate, and with lower long-term levels, especially for sulfate and Na+. Analysis of colocated monitors revealed measurement error for all constituents, especially EC and Na+. Exposure misclassification may be introduced into epidemiological studies of PM2.5 constituents due to spatial variability, and is affected by constituent type and level. When assessing health effects of PM constituents, new methods are needed for estimating exposure and accounting for exposure error induced by spatial variability. PMID:20664652

  4. A one-year comprehensive chemical characterisation of fine aerosol (PM2.5) at urban, suburban and rural background sites in the region of Paris (France)

    NASA Astrophysics Data System (ADS)

    Bressi, M.; Sciare, J.; Ghersi, V.; Bonnaire, N.; Nicolas, J. B.; Petit, J.-E.; Moukhtar, S.; Rosso, A.; Mihalopoulos, N.; Féron, A.

    2013-08-01

    Studies describing the chemical composition of fine aerosol (PM2.5) in urban areas are often conducted for a few weeks only and at one sole site, giving thus a narrow view of their temporal and spatial characteristics. This paper presents a one-year (11 September 2009-10 September 2010) survey of the daily chemical composition of PM2.5 in the region of Paris, which is the second most populated "Larger Urban Zone" in Europe. Five sampling sites representative of suburban (SUB), urban (URB), northeast (NER), northwest (NWR) and south (SOR) rural backgrounds were implemented. The major chemical components of PM2.5 were determined including elemental carbon (EC), organic carbon (OC), and the major ions. OC was converted to organic matter (OM) using the chemical mass closure methodology, which leads to conversion factors of 1.95 for the SUB and URB sites, and 2.05 for the three rural ones. On average, gravimetrically determined PM2.5 annual mass concentrations are 15.2, 14.8, 12.6, 11.7 and 10.8 μg m-3 for SUB, URB, NER, NWR and SOR sites, respectively. The chemical composition of fine aerosol is very homogeneous at the five sites and is composed of OM (38-47%), nitrate (17-22%), non-sea-salt sulfate (13-16%), ammonium (10-12%), EC (4-10%), mineral dust (2-5%) and sea salt (3-4%). This chemical composition is in agreement with those reported in the literature for most European environments. On an annual scale, Paris (URB and SUB sites) exhibits its highest PM2.5 concentrations during late autumn, winter and early spring (higher than 15 μg m-3 on average, from December to April), intermediates during late spring and early autumn (between 10 and 15 μg m-3 during May, June, September, October, and November) and the lowest during summer (below 10 μg m-3 during July and August). PM levels are mostly homogeneous on a regional scale, during the whole project (e.g. for URB plotted against NER sites: slope = 1.06, r2=0.84, n=330), suggesting the importance of mid- or long

  5. A one-year comprehensive chemical characterisation of fine aerosol (PM2.5) at urban, suburban and rural background sites in the region of Paris (France)

    NASA Astrophysics Data System (ADS)

    Bressi, M.; Sciare, J.; Ghersi, V.; Bonnaire, N.; Nicolas, J. B.; Petit, J.-E.; Moukhtar, S.; Rosso, A.; Mihalopoulos, N.; Féron, A.

    2012-11-01

    Studies describing the chemical composition of fine aerosol (PM2.5) in urban areas are often conducted during few weeks only, and at one sole site, giving thus a narrow view of their temporal and spatial characteristics. This paper presents a one-year (11 September 2009-10 September 2010) survey of the daily chemical composition of PM2.5 in the region of Paris, which is the second most populated "Larger Urban Zone" in Europe. Five sampling sites representative of suburban (SUB), urban (URB), northeast (NER), northwest (NWR) and south (SOR) rural backgrounds were implemented. The major chemical components of PM2.5 were determined including elemental carbon (EC), organic carbon (OC), and the major ions. OC was converted to organic matter (OM) using the chemical mass closure methodology, which leads to conversion factors of 1.95 for the SUB and URB sites, and 2.05 for the three rural ones. On average, gravimetrically determined PM2.5 annual mass concentrations are 15.2, 14.8, 12.6, 11.7 and 10.8 μg m-3 for SUB, URB, NER, NWR and SOR sites, respectively. The chemical composition of fine aerosol is very homogeneous at the five sites and is composed of OM (38-47%), nitrate (17-22%), non-sea-salt sulfate (13-16%), ammonium (10-12%), EC (4-10%), mineral dust (2-5%) and sea salt (3-4%). This chemical composition is in agreement with those reported in the literature for most European environments. On the annual scale, Paris (URB and SUB sites) exhibits its highest PM2.5 concentrations during late autumn, winter and early spring (higher than 15 μg m-3 on average, from December to April), intermediates during late spring and early autumn (between 10 and 15 μg m-3 during May, June, September, October, and November) and the lowest during summer (below 10 μg m-3 during July and August). PM levels are mostly homogeneous at the regional scale, on the whole duration of the project (e.g. for URB plotted against NER sites: slope = 1.06, r2 = 0.84, n = 330), suggesting the

  6. Enrichment of fine mica originating from rock aggregate production and its influence on the mechanical properties of bituminous mixtures

    NASA Astrophysics Data System (ADS)

    Miskovsky, K.

    2004-10-01

    Analyses of mica-bearing, crushed granitoid rocks revealed a significant enrichment of free mica in the fine fraction. Qualitative tests of bituminous mixtures with an increasing content of free mica in the fine fraction suggested a considerable deterioration of the mechanical properties of the asphalt mass. The negative influence of fine mica on the mechanical properties of the asphalt mixtures was most likely caused by the ability of mica to adsorb bitumen and to create zones of weakness. This phenomenon seemed to be linked to a preferred orientation (foliation) of the mica particles that was connected to the compaction of asphalt masses during the construction of the surface course. The threshold content at which the fine mica negatively influenced the quality of the bituminous mixtures was estimated to be 30 35 vol.%.

  7. Chemical characterization and redox potential of coarse and fine particulate matter (PM) in underground and ground-level rail systems of the Los Angeles Metro.

    PubMed

    Kam, Winnie; Ning, Zhi; Shafer, Martin M; Schauer, James J; Sioutas, Constantinos

    2011-08-15

    A campaign was conducted to assess personal exposure of coarse (2.5 μm < d(p) < 10 μm) and fine (d(p) < 2.5 μm) PM for two lines of the L.A. Metro-a subway (red) and light-rail (gold) line. Concurrent measurements were taken at University of Southern California (USC) to represent ambient conditions. A comprehensive chemical analysis was performed including total and water-soluble metals, inorganic ions, elemental and organic carbon, and organic compounds. Mass balance showed that in coarse PM, iron makes up 27%, 6%, and 2% of gravimetric mass for the red line, the gold line, and USC, respectively; in fine PM, iron makes up 32%, 3%, and 1%. Ambient air is the primary source of inorganic ions and organic compounds for both lines. Noncrustal metals, particularly Cr, Mn, Co, Ni, Mo, Cd, and Eu, were elevated for the red line and, to a lesser degree, the gold line. Mo exhibited the greatest crustal enrichment factors. The enriched species were less water-soluble on the red line than corresponding species on the gold line. Bivariate analysis showed that reactive oxygen species (ROS) activity is strongly correlated with water-soluble Fe (R(2) = 0.77), Ni (R(2 )= 0.95), and OC (R(2 )= 0.92). A multiple linear regression model (R(2) = 0.94, p < 0.001) using water-soluble Fe and OC as predictor variables was developed to explain the variance in ROS. In addition, PM from the red line generates 65% and 55% more ROS activity per m(3) of air than PM from USC and the gold line, respectively; however, one unit of PM mass from the gold line may be as intrinsically toxic as one unit of PM from the red line.

  8. Genotoxicity, inflammation and physico-chemical properties of fine particle samples from an incineration energy plant and urban air.

    PubMed

    Sharma, Anoop Kumar; Jensen, Keld Alstrup; Rank, Jette; White, Paul A; Lundstedt, Staffan; Gagne, Remi; Jacobsen, Nicklas R; Kristiansen, Jesper; Vogel, Ulla; Wallin, Håkan

    2007-10-04

    Airborne particulate matter (PM) was sampled by use of an electrostatic sampler in an oven hall and a receiving hall in a waste-incineration energy plant, and from urban air in a heavy-traffic street and from background air in Copenhagen. PM was sampled for 1-2 weeks, four samples at each site. The samples were extracted and examined for mutagenicity in Salmonella typhimurium strains TA98, YG1041 and YG5161, for content of inorganic elements and for the presence of eight polycyclic aromatic hydrocarbons. The induction of IL-6 and IL-8 mRNA expression and the presence of DNA damage - tested by the comet assay - were determined after 24-h incubations with human A549 lung epithelial cells. The PM(2.5) concentration was about twofold greater in the oven hall than in the receiving hall. The particle size distribution in the receiving hall was similar to that in street air (maximum mode at about 25nm), but the distribution was completely different in the oven hall (maximum mode at about 150nm). Also chemically, the samples from the oven hall were highly different from the other samples. PM extracts from the receiving hall, street and background air were more mutagenic than the PM extracts from the oven hall. PM from all four sites caused similar levels of DNA damage in A549 cells; only the oven hall samples gave results that were statistically significantly different from those obtained with street-air samples. The receiving hall and the urban air samples were similarly inflammatory (relative IL-8 mRNA expression), whereas the oven hall did not cause a statistically significant increase in IL-8 mRNA expression. A principal component analysis separated the oven hall and the receiving hall by the first principal component. These two sites were separated from street and background air with the second principal component. Several clusters of constituents were identified. One cluster consisted of all the polycyclic aromatic hydrocarbons (PAH), several groups of metals and one

  9. Bilirubin oxidation products (BOXes): synthesis, stability and chemical characteristics

    PubMed Central

    Wurster, W. L.; Pyne-Geithman, G. J.; Peat, I. R.; Clark, J. F.

    2009-01-01

    Summary Bilirubin oxidation products (BOXes) have been a subject of interest in neurosurgery because they are purported to be involved in subarachnoid hemorrhage induced cerebral vasospasm. There is a growing body of information concerning their putative role in vasospasm; however, there is a dearth of information concerning the chemical and biochemical characteristics of BOXes. A clearer understanding of the synthesis, stability and characteristics of BOXes will be important for a better understanding of the role of BOXes post subarachnoid hemorrhage. We used hydrogen peroxide to oxidize bilirubin and produce BOXes. BOXes were extracted and analyzed using conventional methods such as HPLC and mass spectrometry. Characterization of the stability BOXes demonstrates that light can photodegrade BOXes with a t1/2 of up to 10 h depending upon conditions. Mixed isomers of BOXes have an apparent extinction coefficient of ε = 6985, and a λmax of 310 nm. BOXes are produced by the oxidation of bilirubin, yielding a mixture of isomers: 4-methyl-5-oxo-3-vinyl-(1,5-dihydropyrrol-2-ylidene)acetamide (BOX A) and 3-methyl-5-oxo-4-vinyl-(1,5-dihydropyrrol-2-ylidene)acetamide (BOX B). The BOXes are photodegraded by ambient light and can be analyzed spectrophotometrically with their extinction coefficient as well as with HPLC or mass spectrometry. Their small molecular weight and photodegradation may have made them difficult to characterize in previous studies. PMID:18456996

  10. Experimental EOS and Chemical Studies of High-Pressure Detonation Products and Product Mixtures

    SciTech Connect

    Zaug, J M; Fried, L E; Crowhurst, J C; Hansen, D W; Howard, W M; Lee, G S; Pagoria, P F; Abramson, E H

    2002-07-01

    We present equation of state results from impulsively stimulated light scattering (ISLS) experiments conducted in diamond anvil cells on pure supercritical fluids, and supercritical fluid mixtures. We have made measurements on fluid H2O (water), CH2O (formaldehyde), and CH3OH (methanol). Sound speeds measured through ISLS have allowed us to refine existing potential models used in the EXP6 detonation product library [Fried, L. E., and Howard, W. M., J. Chem. Phys. 109 (17): 7338-7348 (1998).]. The refined models allow us to more accurately assess the chemical composition at the Chapman-Jouget (C-J) state of common explosives. We predict that water and formaldehyde are present in appreciable quantities at the C-J state of HMX, RDX, and NM. Methanol is predicted to be present only in trace quantities at the C-J state. In the case of methanol, chemical decomposition and phase separation was observed at high temperatures. We are developing micro-FTIR and Raman techniques to determine the chemical composition of the phase separated detonation products.

  11. Experimental EOS and Chemical Studies of High-Pressure Detonation Products and Product Mixtures

    SciTech Connect

    Zaug, J M; Fried, L E; Crowhurst, J C; Hansen, D W; Howard, W M; Lee, G S; Pagoria, P F; Abramson, E H

    2002-08-06

    We present equation of state results from impulsively stimulated light scattering (ISLS) experiments conducted in diamond anvil cells on pure supercritical fluids, and supercritical fluid mixtures. We have made measurements on fluid H2O (water), CH2O (formaldehyde), and CH3OH (methanol). Sound speeds measured through ISLS have allowed us to refine existing potential models used in the Em6 detonation product library [Fried, L. E., and Howard, W. M., J. Chem. Phys. 109 (17): 7338-7348 (1998).]. The refined models allow us to more accurately assess the chemical composition at the Chapman-Jouget (C-J) state of common explosives. We predict that water and formaldehyde are present in appreciable quantities at the C-J state of HMX, RDX, and NM. Methanol is predicted to be present only in trace quantities at the C-J state. In the case of methanol, chemical decomposition and phase separation was observed at high temperatures. We are developing micro-FTIR and Raman techniques to determine the chemical composition of the phase separated detonation products.

  12. Action against Vibrio cholerae O1 Tox+ of chemical products used in the lemon production.

    PubMed

    de Castillo, M C; de Allori, C G; de Gutiérrez, R C; de Saab, O A; de Fernández, N P; de Ruiz, C S; de Ruiz Holgado, A P; de Nader, O

    1998-01-01

    Tucuman is the first lemon exporting province in Argentina and the fourth lemon exporter in the world. The present work was set up to study the survival of Vibrio cholerae O1 Tox+ after application of different chemical products used in the lemon production (from its cultivation until its packing). The following products were studied: copper oxychloride, benomil (a carbamate), active chlorine, sodium-o-phenylphenoate, guazatine (a polyamine mixture), imazalil (an imidazole) and fresh and dehydrated lemon peel. Using different dilutions of the products above mentioned antimicrobial tests were carried out with different exposure times against V. cholerae Serogroup O1, Biotype El Tor, Serotype Inaba. The microorganism was used at concentrations of 10(2), 10(4), 10(6) and 10(8) CFU ml-1, the latter one being considered as an infectious dose. The following results were obtained: 1) Active chlorine (chlorinated water) showed bactericidal activity at concentrations of 0.5 x 10(-1), 10(-1), y 2 x 10(-1) g l-1 after 10 min of exposure time. 2) Copper oxychloride, sodium-o-phenylphenoate, guazatine and imazalil showed bactericidal activity against V. cholerae at concentrations of 10(2) and 10(4) CFU ml-1. 3) Due to the fact that the fruit is successively sprayed with several chemical products during its cultivation, it could be proposed that the result of the successive treatments is superior to the result of a treatment with each of the individual products. This consideration should be taken into account when evaluating the eventual protection of the lemon.

  13. Chemical composition and minerals in pyrite ash of an abandoned sulphuric acid production plant.

    PubMed

    Oliveira, Marcos L S; Ward, Colin R; Izquierdo, Maria; Sampaio, Carlos H; de Brum, Irineu A S; Kautzmann, Rubens M; Sabedot, Sydney; Querol, Xavier; Silva, Luis F O

    2012-07-15

    The extraction of sulphur produces a hematite-rich waste, known as roasted pyrite ash, which contains significant amounts of environmentally sensitive elements in variable concentrations and modes of occurrence. Whilst the mineralogy of roasted pyrite ash associated with iron or copper mining has been studied, as this is the main source of sulphur worldwide, the mineralogy, and more importantly, the characterization of submicron, ultrafine and nanoparticles, in coal-derived roasted pyrite ash remain to be resolved. In this work we provide essential data on the chemical composition and nanomineralogical assemblage of roasted pyrite ash. XRD, HR-TEM and FE-SEM were used to identify a large variety of minerals of anthropogenic origin. These phases result from highly complex chemical reactions occurring during the processing of coal pyrite of southern Brazil for sulphur extraction and further manufacture of sulphuric acid. Iron-rich submicron, ultrafine and nanoparticles within the ash may contain high proportions of toxic elements such as As, Se, U, among others. A number of elements, such as As, Cr, Cu, Co, La, Mn, Ni, Pb, Sb, Se, Sr, Ti, Zn, and Zr, were found to be present in individual nanoparticles and submicron, ultrafine and nanominerals (e.g. oxides, sulphates, clays) in concentrations of up to 5%. The study of nanominerals in roasted pyrite ash from coal rejects is important to develop an understanding on the nature of this by-product, and to assess the interaction between emitted nanominerals, ultra-fine particles, and atmospheric gases, rain or body fluids, and thus to evaluate the environmental and health impacts of pyrite ash materials.

  14. Chemical Hydride Slurry for Hydrogen Production and Storage

    SciTech Connect

    McClaine, Andrew W

    2008-09-30

    The purpose of this project was to investigate and evaluate the attractiveness of using a magnesium chemical hydride slurry as a hydrogen storage, delivery, and production medium for automobiles. To fully evaluate the potential for magnesium hydride slurry to act as a carrier of hydrogen, potential slurry compositions, potential hydrogen release techniques, and the processes (and their costs) that will be used to recycle the byproducts back to a high hydrogen content slurry were evaluated. A 75% MgH2 slurry was demonstrated, which was just short of the 76% goal. This slurry is pumpable and storable for months at a time at room temperature and pressure conditions and it has the consistency of paint. Two techniques were demonstrated for reacting the slurry with water to release hydrogen. The first technique was a continuous mixing process that was tested for several hours at a time and demonstrated operation without external heat addition. Further work will be required to reduce this design to a reliable, robust system. The second technique was a semi-continuous process. It was demonstrated on a 2 kWh scale. This system operated continuously and reliably for hours at a time, including starts and stops. This process could be readily reduced to practice for commercial applications. The processes and costs associated with recycling the byproducts of the water/slurry reaction were also evaluated. This included recovering and recycling the oils of the slurry, reforming the magnesium hydroxide and magnesium oxide byproduct to magnesium metal, hydriding the magnesium metal with hydrogen to form magnesium hydride, and preparing the slurry. We found that the SOM process, under development by Boston University, offers the lowest cost alternative for producing and recycling the slurry. Using the H2A framework, a total cost of production, delivery, and distribution of $4.50/kg of hydrogen delivered or $4.50/gge was determined. Experiments performed at Boston

  15. Estimation of aerosol complex refractive indices for both fine and coarse modes simultaneously based on AERONET remote sensing products

    NASA Astrophysics Data System (ADS)

    Zhang, Ying; Li, Zhengqiang; Zhang, Yuhuan; Li, Donghui; Qie, Lili; Che, Huizheng; Xu, Hua

    2017-09-01

    Climate change assessment, especially model evaluation, requires a better understanding of complex refractive indices (CRIs) of atmospheric aerosols - separately for both fine and coarse modes. However, the widely used aerosol CRI obtained by the global Aerosol Robotic Network (AERONET) corresponds to total-column aerosol particles without separation for fine and coarse modes. This paper establishes a method to separate CRIs of fine and coarse particles based on AERONET volume particle size distribution (VPSD), aerosol optical depth (AOD) and absorbing AOD (AAOD). The method consists of two steps. First a multimodal log-normal distribution that best approximates the AERONET VPSD is found. Then the fine and coarse mode CRIs are found by iterative fitting of AERONET AODs to Mie calculations. The numerical experiment shows good performance for typical water-soluble, biomass burning and dust aerosol types, and the estimated uncertainties on the retrieved sub-mode CRIs are about 0.11 (real part) and 78 % (imaginary part). The 1-year measurements at the AERONET Beijing site are processed, and we obtain CRIs of 1.48-0.010i (imaginary part at 440 nm is 0.012) for fine mode particles and 1.49-0.004i (imaginary part at 440 nm is 0.007) for coarse mode particles, for the period of 2014-2015. Our results also suggest that both fine and coarse aerosol mode CRIs have distinct seasonal characteristics; in particular, CRIs of fine particles in winter season are significantly higher than summer due to possible anthropogenic influences.

  16. Production of fuels and chemicals from waste by microbiomes.

    PubMed

    Marshall, Christopher W; LaBelle, Edward V; May, Harold D

    2013-06-01

    The demand for chemicals and fuels will continue to grow simultaneously with the costly requirement to treat solid waste, wastewater, and regarding climate change, carbon dioxide. A dual benefit is at hand if waste could be converted to valuable chemicals. The application of stable chemical producing microbiomes adapted to these waste streams may turn this challenge into an opportunity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Relative Configuration of Natural Products Using NMR Chemical Shifts

    USDA-ARS?s Scientific Manuscript database

    By comparing calculated with experimental NMR chemical shifts, we were able to determine the relative configurations of three monoterpene diastereomers produced by the walkingstick Anisomorpha buprestoides. The combined RMSDs of both 1H and 13C quantum chemically calculated shifts were able to predi...

  18. Production of platform chemical itaconic acid from pentose sugars

    USDA-ARS?s Scientific Manuscript database

    In recent years, itaconic acid (IA), an unsaturated five carbon dicarboxylic acid, has gained importance as a fully sustainable building block chemical (platform chemical) for a wide range of applications in the manufacturing of various synthetic resins, coatings, and polymers. It is currently produ...

  19. Chemical partitioning of fine particle-bound metals on haze-fog and non-haze-fog days in Nanjing, China and its contribution to human health risks

    NASA Astrophysics Data System (ADS)

    Li, Huiming; Wu, Hongfei; Wang, Qin'geng; Yang, Meng; Li, Fengying; Sun, Yixuan; Qian, Xin; Wang, Jinhua; Wang, Cheng

    2017-01-01

    Information on chemical partitioning and associated risk of airborne metals, particularly during a haze-fog episode, is limited. Fine particulate matter (PM2.5) was collected during a severe haze-fog event in winter and non-haze-fog periods in summer and fall from an urban region of a typical Chinese mega-city, Nanjing. The particulate-bound metals (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, Pb, Sr, Ti, V, and Zn) were chemically fractionated in a four-step sequential extraction procedure and human health risk was assessed. During the haze-fog episode, PM2.5 was extremely elevated with a mean concentration of 281 μg/m3 (range: 77-431 μg/m3), whereas the mean PM2.5 concentrations in summer and fall periods were 86 μg/m3 (range: 66-111 μg/m3) and 77 μg/m3 (range: 42-131 μg/m3), respectively. All elements had significantly higher concentrations and many metals exceeded relevant limits on haze-fog days. K, Na, Sr, Zn, Mo, Ca, Cd, Mg, Mn, Cu, Ba, Cr and As all showed relatively high proportions of the soluble and exchangeable fraction and strong bio-accessible potential. High temperature and humidity may increase the bio-accessible fraction of many airborne metals. The hazard index for potential toxic metals was 0.115, which was lower than the safe limit (1). However, the combined carcinogenic risk was 1.32 × 10- 6 for children and 5.29 × 10- 6 for adults, with both values being higher than the precautionary criterion (10- 6). Results of this study provide information for the behavior and risk mitigation of airborne metals.

  20. Chemical Composition of the Aerosol Fine Fraction during African Dust Events as part of the Dust ATtACk Experiment in the Caribbean Region

    NASA Astrophysics Data System (ADS)

    Vallejo, Pamela; Formenti, Paola; Desboeufs, Karine; Quiñones, Mariana; Chevaillier, Servanne; Santos, Stephanie; Andrews, Elizabeth; Ogren, John A.; Mayol-Bracero, Olga L.

    2015-04-01

    We present results on the assessment of aerosols' chemical composition at the atmospheric observatory of Cabezas de San Juan in Fajardo, Puerto Rico, during the summers of 2011 and 2012, where periods in the presence and absence of dust were studied under the framework of the Dust-ATtACk (Dust- Aging and Transport, from Africa to the Caribbean) experiment. Dust events were identified through observation and using air-mass back-trajectories, Saharan Air Layer images, measurements of aerosol optical thickness (AOT), in situ scattering and absorption coefficients, and chemical analyses. Results obtained for intense dust events were characterized by higher concentration of coarse particles, higher scattering and absorption coefficients (up to 100 Mm-1 and 5 Mm-1 at 550 and 530 nm, respectively), higher AOT (from 0.4 to 0.8) values, and higher concentration of elements associated with mineral dust (e.g., Si μ3 g/m3 compared to background concentrations of 0.15 μg/m3, obtained from XRF analysis). Elemental composition of the fine fraction (Dp < 1.8 μm), analyzed by ICP-OES, also yielded higher average concentrations during dust events of, for example, Fe (0.045 μg m-3, vs 0.016 μg m-3 during low or no dust). Detailed results of the submicron fraction composition for the carbonaceous aerosol (total carbon, organic carbon, black carbon), total nitrogen, the water-soluble organic carbon, water-soluble ions, and the elemental composition with their possible sources will be presented at the meeting.

  1. Retail sales of scheduled listed chemical products; self-certification of regulated sellers of scheduled listed chemical products. Interim final rule with request for comment.

    PubMed

    2006-09-26

    In March 2006, the President signed the Combat Methamphetamine Epidemic Act of 2005, which establishes new requirements for retail sales of over-the-counter (nonprescription) products containing the List I chemicals ephedrine, pseudoephedrine, and phenylpropanolamine. The three chemicals can be used to manufacture methamphetamine illegally. DEA is promulgating this rule to incorporate the statutory provisions and make its regulations consistent with the new requirements. This action establishes daily and 30-day limits on the sales of scheduled listed chemical products to individuals and requires recordkeeping on most sales.

  2. Development of a consumer product ingredient database for chemical exposure screening and prioritization.

    PubMed

    Goldsmith, M-R; Grulke, C M; Brooks, R D; Transue, T R; Tan, Y M; Frame, A; Egeghy, P P; Edwards, R; Chang, D T; Tornero-Velez, R; Isaacs, K; Wang, A; Johnson, J; Holm, K; Reich, M; Mitchell, J; Vallero, D A; Phillips, L; Phillips, M; Wambaugh, J F; Judson, R S; Buckley, T J; Dary, C C

    2014-03-01

    Consumer products are a primary source of chemical exposures, yet little structured information is available on the chemical ingredients of these products and the concentrations at which ingredients are present. To address this data gap, we created a database of chemicals in consumer products using product Material Safety Data Sheets (MSDSs) publicly provided by a large retailer. The resulting database represents 1797 unique chemicals mapped to 8921 consumer products and a hierarchy of 353 consumer product "use categories" within a total of 15 top-level categories. We examine the utility of this database and discuss ways in which it will support (i) exposure screening and prioritization, (ii) generic or framework formulations for several indoor/consumer product exposure modeling initiatives, (iii) candidate chemical selection for monitoring near field exposure from proximal sources, and (iv) as activity tracers or ubiquitous exposure sources using "chemical space" map analyses. Chemicals present at high concentrations and across multiple consumer products and use categories that hold high exposure potential are identified. Our database is publicly available to serve regulators, retailers, manufacturers, and the public for predictive screening of chemicals in new and existing consumer products on the basis of exposure and risk.

  3. 21 CFR 1310.16 - Exemptions for certain scheduled listed chemical products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 9 2011-04-01 2011-04-01 false Exemptions for certain scheduled listed chemical... RECORDS AND REPORTS OF LISTED CHEMICALS AND CERTAIN MACHINES § 1310.16 Exemptions for certain scheduled listed chemical products. (a) Upon the application of a manufacturer of a scheduled listed...

  4. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... additionally planned production of Schedule 3 chemicals. 714.3 Section 714.3 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance...

  5. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... additionally planned production of Schedule 3 chemicals. 714.3 Section 714.3 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance...

  6. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... additionally planned production of Schedule 3 chemicals. 714.3 Section 714.3 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance...

  7. 15 CFR 714.3 - Advance declaration requirements for additionally planned production of Schedule 3 chemicals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... additionally planned production of Schedule 3 chemicals. 714.3 Section 714.3 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) BUREAU OF INDUSTRY AND SECURITY, DEPARTMENT OF COMMERCE CHEMICAL WEAPONS CONVENTION REGULATIONS ACTIVITIES INVOLVING SCHEDULE 3 CHEMICALS § 714.3 Advance...

  8. Formic acid production using a microbial electrolysis desalination and chemical-production cell.

    PubMed

    Lu, Yaobin; Luo, Haiping; Yang, Kunpeng; Liu, Guangli; Zhang, Renduo; Li, Xiao; Ye, Bo

    2017-06-13

    The aim of this study was to investigate the feasibility and optimization of formic acid production in the microbial electrolysis desalination and chemical-production cell (MEDCC). The maximum current density in the MEDCC with 72cm of the anode fiber length (72-MEDCC) reached 24.0±2.0A/m(2), which was much higher than previously reported. The maximum average formic acid production rate in the 72-MEDCC was 5.28 times higher than that in the MEDCC with 24cm of the anode fiber length (37.00±1.15vs. 7.00±0.25mg/h). High performance in the 72-MEDCC was attributed to small membrane spacing (1mm), high flow rate (1500μL/min) on the membrane surface and high anode biomass. The minimum electricity consumption of 0.34±0.04kWh/kg in the 72-MEDCC was only 3.1-18.8% of those in the EDBMs. The MEDCC should be a promising technology for the formic acid production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. CO2 AND N-FERTILIZATION EFFECTS ON FINE ROOT LENGTH, PRODUCTION, AND MORTALITY: A 4-YEAR PONDEROSA PINE STUDY

    EPA Science Inventory

    We conducted a 4-year study of Pinus ponderosa fine root (<2 mm) responses to atmospheric CO2 and N-fertilization. Seedlings were grown in open-top chambers at 3 CO2 levels (ambient, ambient+175 mol/mol, ambient+350 mol/mol) and 3 N-fertilization levels (0, 10, 20 g?m-2?yr-1). ...

  10. ASSESSING THE EFFECTS OF GLOBAL CLIMATE CHANGE ON THE PRODUCTION AND MORTALITY OF DOUGLAS FIR FINE ROOTS USING MINIRHIZOTRONS

    EPA Science Inventory

    Fine roots (roots 2 mm in diameter) are one of the principal absorptive surfaces for water and nutrients in terrestrial plants. As such they are vital for plant growth and survival, while their turnover serves as a primary mechanism for carbon addition to soil. Little is known...

  11. CO2 AND N-FERTILIZATION EFFECTS ON FINE ROOT LENGTH, PRODUCTION, AND MORTALITY: A 4-YEAR PONDEROSA PINE STUDY

    EPA Science Inventory

    We conducted a 4-year study of Pinus ponderosa fine root (<2 mm) responses to atmospheric CO2 and N-fertilization. Seedlings were grown in open-top chambers at 3 CO2 levels (ambient, ambient+175 mol/mol, ambient+350 mol/mol) and 3 N-fertilization levels (0, 10, 20 g?m-2?yr-1). ...

  12. ASSESSING THE EFFECTS OF GLOBAL CLIMATE CHANGE ON THE PRODUCTION AND MORTALITY OF DOUGLAS FIR FINE ROOTS USING MINIRHIZOTRONS

    EPA Science Inventory

    Fine roots (roots 2 mm in diameter) are one of the principal absorptive surfaces for water and nutrients in terrestrial plants. As such they are vital for plant growth and survival, while their turnover serves as a primary mechanism for carbon addition to soil. Little is known...

  13. Evaluation of Consumer Product Co-occurrence to Inform Chemical Exposure

    EPA Science Inventory

    Consumer products are an important target of chemical innovation. Used daily for personal hygiene, home care, disinfection and cleaning, consumer products provide a host of benefits, and also an efficient delivery vehicle for a variety of chemicals into our homes and bodies. Al...

  14. Evaluation of Consumer Product Co-occurrence to Inform Chemical Exposure

    EPA Science Inventory

    Consumer products are an important target of chemical innovation. Used daily for personal hygiene, home care, disinfection and cleaning, consumer products provide a host of benefits, and also an efficient delivery vehicle for a variety of chemicals into our homes and bodies. Al...

  15. New Tools for Investigating Chemical and Product Use

    EPA Science Inventory

    - The timely characterization of the human and ecological risk posed by thousands of existing and emerging commercial chemicals is a critical challenge - High throughput (HT) risk prioritization relies on hazard and exposure characterization - While advances have been made ...

  16. Development of a chemical oxygen - iodine laser with production of atomic iodine in a chemical reaction

    SciTech Connect

    Censky, M; Spalek, O; Jirasek, V; Kodymova, J; Jakubec, I

    2009-11-30

    The alternative method of atomic iodine generation for a chemical oxygen - iodine laser (COIL) in chemical reactions with gaseous reactants is investigated experimentally. The influence of the configuration of iodine atom injection into the laser cavity on the efficiency of the atomic iodine generation and small-signal gain is studied. (lasers)

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

    PubMed

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

    2016-01-01

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

  18. Archaeological and chemical evidence for early salt production in China

    PubMed Central

    Flad, Rowan; Zhu, Jiping; Wang, Changsui; Chen, Pochan; von Falkenhausen, Lothar; Sun, Zhibin; Li, Shuicheng

    2005-01-01

    Salt production and trade is thought to be critical to the development of all states and emergent empires. Until now, however, scientific evidence of early salt production has rarely been presented, and no studies of early Chinese salt production have provided unequivocal proof. Here, we report x-ray fluorescence, x-ray diffraction, and scanning electron microscopy (SEM) analyses that demonstrate that salt was the primary product during the first millennium before Christ (B.C.) at Zhongba in Central China. This work provides an early example of salt production discovered in China and presents a methodology for evaluating salt production sites in other regions. PMID:16116100

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

    PubMed

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

    2016-09-01

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

  20. Photosynthetic terpene hydrocarbon production for fuels and chemicals

    USDA-ARS?s Scientific Manuscript database

    Photosynthetic terpene production[ED1] represents an energy and carbon-efficient route for hydrocarbon fuel production. Diverse terpene structures also provide the potential to produce next-generation 'drop-in' hydrocarbon fuel molecules. However, it is highly challenging to achieve efficient redire...

  1. Production of levulinic acid and use as a platform chemical for derived products

    SciTech Connect

    Bozell, J.J.; Moens, L.; Elliott, D.C.; Wang, Y.; Neuenscwander, G.G.; Fitzpatrick, S.W.; Bilski, R.J.; Jarnefeld, J.L.

    1999-07-01

    Levulinic acid (LA) can be produced cost effectively and in high yield from renewable feedstocks in a new industrial process. The technology is being demonstrated on a one ton/day scale at a facility in South Glens Falls, New York. Low cost LA can be used as a platform chemical for the production of a wide range of value-added products. This research has demonstrated that LA can be converted to methyltetrahydrofuran (MTHF), a solvent and fuel extender. MTHF is produced in {gt}80% molar yield via a single stage catalytic hydrogenation process. A new preparation of {delta}-aminolevulinic acid (DALA), a broad spectrum herbicide from LA has also been developed. Each step in this new process proceeds in high ({gt}80%) yield and affords DALA (as the hydrochloride salt) in greater than 90% purity, giving a process that could be commercially viable. LA is also being investigated as a starting material for the production of diphenolic acid (DPA), a direct replacement for bisphenol A.

  2. [Serious product accidents due to the chemical substances used in household products in fiscal years 2007 and 2008].

    PubMed

    Isama, Kazuo

    2009-01-01

    The revised consumer product safety law was enforced in 2007. Then, the collection and publication system of the information of product accidents was newly included. Serious product accidents due to the chemical substances used in household products had 32 cases in fiscal years 2007 and 2008. These household products were a desk mat, a sectional bed, a spray-type adhesive, a paint and an adhesive for table tennis rackets. The safety measure of the household product was explained based on the law for the control of household products containing harmful substances.

  3. Metabolic engineering for production of biorenewable fuels and chemicals: contributions of synthetic biology.

    PubMed

    Jarboe, Laura R; Zhang, Xueli; Wang, Xuan; Moore, Jonathan C; Shanmugam, K T; Ingram, Lonnie O

    2010-01-01

    Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes. It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol. We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors.

  4. Metabolic Engineering for Production of Biorenewable Fuels and Chemicals: Contributions of Synthetic Biology

    PubMed Central

    Jarboe, Laura R.; Zhang, Xueli; Wang, Xuan; Moore, Jonathan C.; Shanmugam, K. T.; Ingram, Lonnie O.

    2010-01-01

    Production of fuels and chemicals through microbial fermentation of plant material is a desirable alternative to petrochemical-based production. Fermentative production of biorenewable fuels and chemicals requires the engineering of biocatalysts that can quickly and efficiently convert sugars to target products at a cost that is competitive with existing petrochemical-based processes. It is also important that biocatalysts be robust to extreme fermentation conditions, biomass-derived inhibitors, and their target products. Traditional metabolic engineering has made great advances in this area, but synthetic biology has contributed and will continue to contribute to this field, particularly with next-generation biofuels. This work reviews the use of metabolic engineering and synthetic biology in biocatalyst engineering for biorenewable fuels and chemicals production, such as ethanol, butanol, acetate, lactate, succinate, alanine, and xylitol. We also examine the existing challenges in this area and discuss strategies for improving biocatalyst tolerance to chemical inhibitors. PMID:20414363

  5. 76 FR 1067 - Testing of Certain High Production Volume Chemicals; Second Group of Chemicals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-07

    ... physical/chemical properties and biodegradation); ecotoxicity (in fish, Daphnia, and algae); acute toxicity... toxicity (gene mutations and chromosomal aberrations). Ecotoxicity (studies in fish, Daphnia, and algae..., Daphnia, and algae); acute toxicity; genetic toxicity (gene mutations and chromosomal aberrations);...

  6. Studies on the Wholesomeness of Ready-to-eat Meat Products II. Chemical Evaluation of Comminuted Heated Products

    PubMed Central

    Saschenbrecker, P. W.; Tittiger, F.

    1973-01-01

    Chemical parameters obtained for 280 samples randomly selected from a variety of ready-to-eat meat products were used to assess nutritional value and wholesomeness. The products investigated in this study include wieners, bologna, meat loaves, sausages, liver products and mortadella. Evaluations of gross composition (moisture, fat, protein,) were found to be insufficient to fully characterize these products. Fat/protein and water/protein quotients reflected well on the nutritional quality. Limitations in the application of these and other parameters are shown. Correlations of physico-chemical parameters such as redox-potential and available water to susceptibility to bacterial spoilage within this closely defined group were statistically insignificant. PMID:4265553

  7. Fine Arts.

    ERIC Educational Resources Information Center

    Danzer, Gerald A.; Newman, Mark

    1992-01-01

    Discusses the use of fine arts as sources to enrich the study of history. Suggests that such works will serve as barometers of change, examples of cross-cultural influences, and political messages. Includes suggestions of works and artists from different historic periods. (DK)

  8. Fine Arts.

    ERIC Educational Resources Information Center

    Danzer, Gerald A.; Newman, Mark

    1992-01-01

    Discusses the use of fine arts as sources to enrich the study of history. Suggests that such works will serve as barometers of change, examples of cross-cultural influences, and political messages. Includes suggestions of works and artists from different historic periods. (DK)

  9. Chemical fractionation of arsenic and heavy metals in fine particle matter and its implications for risk assessment: A case study in Nanjing, China

    NASA Astrophysics Data System (ADS)

    Li, Huiming; Wang, Jinhua; Wang, Qin'geng; Qian, Xin; Qian, Yu; Yang, Meng; Li, Fengying; Lu, Hao; Wang, Cheng

    2015-02-01

    A four-step sequential extraction procedure was used to study the chemical fractionation of As and heavy metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) in fine particulate matter (PM2.5) collected from Nanjing, China. The mass concentrations of most PM2.5 samples exceeded the 24 h standard (75 μg/m3) recommended by the new national ambient air quality standard of China. The most abundant elements were Fe, Zn and Pb, while As and Cd were present at the lowest concentrations. As, Cd, Cu, Mn, Pb and Zn were mostly present in the two mobile fractions, including the soluble and exchangeable fraction (F1), and carbonates, oxides and reducible fraction (F2). Fe had the highest proportion present in the residual fraction (F4). Relatively high proportions of the metals Ni and Cr were present in the oxidizable and sulfidic fraction (F3). High proportions of Zn, As and Cu and lower proportions of Cd, Cr and Fe were present in the potentially mobile phases. The enrichment factor, contamination factor and risk assessment code were calculated to analyze the main sources and assess the environmental risks of the metals in PM2.5. The carcinogenic risks of As, Cd, Ni and Pb were all lower than the accepted criterion of 10-6, whereas the carcinogenic risks of Cr for children and As and Cr for adults were higher than 10-6. The non-carcinogenic health risk of As and heavy metals because of PM2.5 exposure for children and adults were lower than but close to the safe level of 1.

  10. Chemical and magnetic properties of rapidly cooled metastable ferri-ilmenite solid solutions - IV: the fine structure of self-reversed thermoremanent magnetization

    NASA Astrophysics Data System (ADS)

    Robinson, Peter; McEnroe, S. A.; Fabian, K.; Harrison, R. J.; Thomas, C. I.; Mukai, H.

    2014-03-01

    Magnetic experiments, a Monte Carlo simulation and transmission electron microscopy observations combine to confirm variable chemical phase separation during quench and annealing of metastable ferri-ilmenite compositions, caused by inhomogeneous Fe-Ti ordering and anti-ordering. Separation begins near interfaces between growing ordered and anti-ordered domains, the latter becoming progressively enriched in ilmenite component, moving the Ti-impoverished hematite component into Fe-enriched diffusion waves near the interfaces. Even when disordered regions are eliminated, Fe-enriched waves persist and enlarge on anti-phase boundaries between growing and shrinking ordered and anti-ordered domains. Magnetic results and conceptual models show that magnetic ordering with falling T initiates in the Fe-enriched wave crests. Although representing only a tiny fraction of material, identified at highest Ts on a field-cooling curve, they control the `pre-destiny' of progressive magnetization at lower T. They can provide a positive magnetic moment in a minority of ordered ferrimagnetic material, which, by exchange coupling, then creates a self-reversed negative moment in the remaining majority. Four Ts or T ranges are recognized on typical field-cooling curves: TPD is the T range of `pre-destination'; TC is the predominant Curie T where major positive magnetization increases sharply; TMAX is where magnetization reaches a positive maximum, beyond which it is outweighed by self-reversed magnetization and TZM is the T where total magnetization passes zero. Disposition of these Ts on cooling curves indicate the fine structure of self-reversed thermoremanent magnetization. These results confirm much earlier suspicions that the `x-phase' responsible for self-reversed magnetization resides in Fe-enriched phase boundaries.

  11. Chemical Characterisation of the Coarse and Fine Particulate Matter in the Environment of an Underground Railway System: Cytotoxic Effects and Oxidative Stress—A Preliminary Study

    PubMed Central

    Spagnolo, Anna Maria; Ottria, Gianluca; Perdelli, Fernanda; Cristina, Maria Luisa

    2015-01-01

    Background: Exposure to the particulate matter produced in underground railway systems is arousing increasing scientific interest because of its health effects. The aim of our study was to evaluate the airborne concentrations of PM10 and three sub-fractions of PM2.5 in an underground railway system environment in proximity to platforms and in underground commercial areas within the system, and to compare these with the outdoor airborne concentrations. We also evaluated the metal components, the cytotoxic properties of the various fractions of particulate matter (PM) and their capacity to induce oxidative stress. Method: We collected the coarse fraction (5–10 µm) and the fine fractions (1–2.5 µm; 0.5–1 µm; 0.25–0.5 µm). Chemical characterisation was determined by means of spectrometry. Cytotoxicity and oxidative stress were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Reactive Oxygen Species (ROS) assessment. Results: The concentrations of both PM10 and PM2.5 proved to be similar at the three sampling sites. Iron and other transition metals displayed a greater concentration at the subway platform than at the other two sites. The 2.5–10 µm and 1–2.5 µm fractions of PM from all three sampling sites determined a greater increase in ROS; the intensity of oxidative stress progressively declined as particle diameter diminished. Moreover, ROS concentrations were correlated with the concentrations of some transition metals, namely Mn, Cr, Ti, Fe, Cu, Zn, Ni and Mo. All particulate matter fractions displayed lower or similar ROS values between platform level and the outdoor air. Conclusions: The present study revealed that the underground railway environment at platform level, although containing higher concentrations of some particularly reactive metallic species, did not display higher cytotoxicity and oxidative stress levels than the outdoor air. PMID:25872016

  12. Chemical compositions responsible for inflammation and tissue damage in the mouse lung by coarse and fine particulate samples from contrasting air pollution in Europe.

    PubMed

    Happo, Mikko S; Hirvonen, Maija-Riitta; Halinen, Arja I; Jalava, Pasi I; Pennanen, Arto S; Sillanpaa, Markus; Hillamo, Risto; Salonen, Raimo O

    2008-11-01

    Inflammation is regarded as an important mechanism in mortality and morbidity associated with exposures of cardiorespiratory patients to urban air particulate matter. We investigated the association of the chemical composition and sources of urban air fine (PM(2.5-0.2)) and coarse (PM(10-2.5)) particulate samples with the inflammatory activity in the mouse lung. The particulate samples were collected during selected seasons in six European cities using a high-volume cascade impactor. Healthy C57BL/6J mice were intratracheally instilled with a single dose (10 mg/kg) of the particulate samples. At 4, 12, and 24 h after the exposure, the lungs were lavaged and the bronchoalveolar lavage fluid (BALF) was assayed for indicators of inflammation and tissue damage: cell number, total protein, and cytokines (tumor necrosis factor [TNF]-alpha, interleukin [IL]-6, and KC). Dicarboxylic acids and transition metals, especially Ni and V, in PM(2.5-0.2) correlated positively and some secondary inorganic ions (NO3(-), NH4(+)) negatively with the inflammatory activity. Total organic matter and SO4(2-) had no consistent correlations. In addition, the soil-derived constituents (Ca2+, Al, Fe, Si) showed positive correlations with the PM(2.5-0.2)-induced inflammatory activity, but their role in PM(10-2.5) remained obscure, possibly due to largely undefined biogenic material. Markers of poor biomass and coal combustion, i.e., monosaccharide anhydrides and As, were associated with elevated PAH contents in PM(2.5-0.2) and a consistent immunosuppressive effect. Overall, our results support epidemiological findings that the local sources of incomplete combustion and resuspended road dust are important in urban air particulate pollution-related health effects.

  13. Chemical characterisation of the coarse and fine particulate matter in the environment of an underground railway system: cytotoxic effects and oxidative stress-a preliminary study.

    PubMed

    Spagnolo, Anna Maria; Ottria, Gianluca; Perdelli, Fernanda; Cristina, Maria Luisa

    2015-04-13

    Exposure to the particulate matter produced in underground railway systems is arousing increasing scientific interest because of its health effects. The aim of our study was to evaluate the airborne concentrations of PM10 and three sub-fractions of PM2.5 in an underground railway system environment in proximity to platforms and in underground commercial areas within the system, and to compare these with the outdoor airborne concentrations. We also evaluated the metal components, the cytotoxic properties of the various fractions of particulate matter (PM) and their capacity to induce oxidative stress. We collected the coarse fraction (5-10 µm) and the fine fractions (1-2.5 µm; 0.5-1 µm; 0.25-0.5 µm). Chemical characterisation was determined by means of spectrometry. Cytotoxicity and oxidative stress were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Reactive Oxygen Species (ROS) assessment. The concentrations of both PM10 and PM2.5 proved to be similar at the three sampling sites. Iron and other transition metals displayed a greater concentration at the subway platform than at the other two sites. The 2.5-10 µm and 1-2.5 µm fractions of PM from all three sampling sites determined a greater increase in ROS; the intensity of oxidative stress progressively declined as particle diameter diminished. Moreover, ROS concentrations were correlated with the concentrations of some transition metals, namely Mn, Cr, Ti, Fe, Cu, Zn, Ni and Mo. All particulate matter fractions displayed lower or similar ROS values between platform level and the outdoor air. The present study revealed that the underground railway environment at platform level, although containing higher concentrations of some particularly reactive metallic species, did not display higher cytotoxicity and oxidative stress levels than the outdoor air.

  14. Physical and chemical properties of feedlot pen surfaces located on moderately coarse- and moderately fine-textured soils in southern Alberta.

    PubMed

    Miller, Jim J; Curtis, Tony; Larney, Francis J; McAllister, Tim A; Olson, Barry M

    2008-01-01

    Southern Alberta has the highest density of feedlot cattle in Canada, and there is a concern that leaching of water and contaminants may be greater for feedlots located on coarser-textured than finer-textured soils. Our objective was to determine if infiltration and leaching were greater for a 4-yr-old feedlot located on a moderately coarse-textured (MC) soil compared with two feedlots located on moderately fine-textured (MF) soils (5- and 52-yr-old pens). Various soil physical properties of feedlot pen surfaces were measured, including field-saturated hydraulic conductivity (K(fs)) and near-saturated hydraulic conductivity at -0.9 and -3.9 cm water potential. Selected chemical properties of feedlot soil layers were measured, as well as the chloride content of the soil profile (0-100 cm). Mean K(fs), K(-0.9), and K(-3.9) values were not significantly (P > 0.10) greater at the MC site than the two MF sites, indicating no evidence of greater infiltration on coarser-textured soils. In addition, mean K(fs), K(-0.9), and K(-3.9) values of soils within feedlot pens at all three sites were significantly (P < or = 0.10) reduced by 46 to 78% compared with soil outside the pens. Depth of chloride accumulation was greatest at the 52-yr-old feedlot on MF soil (60-70 cm), followed by 4-yr-old feedlot on MC soil (40-50 cm) and 5-yr-old feedlot on MF soil (30-40 cm). Visual inspection determined that the black interface layer formed within 2 mo of cattle stocking at all three sites.

  15. Succinic Acid-A Model Building Block for Chemical Production from Renewable Resources

    SciTech Connect

    Werpy, Todd A.; Frye, John G.; Holladay, John E.

    2006-04-01

    One of the major considerations for the development of new technologies that can be utilized in a corn wet mill for the production of new chemical products is the concept of platform building blocks. This concept is based on the fact that a single building block has the potential to create a significant number of final products. Succinic acid represents a building block that can be used as a starting material for producing a large number of commodity and specialty chemicals.

  16. [Impact of the industrial enzyme progress on the production of chemicals].

    PubMed

    Duan, Gang

    2009-12-01

    Industrial enzymes play dual roles for the production of chemicals and biochemicals, one is to act as direct catalyst for the reaction, the other is to participate in the fermentation process to convert substrates to fermentable sugars or to make it more efficient. The review briefs the applications of industrial enzymes for chemical productions, with emphasis on direct conversion of starch and their roles in bioethanol production process, also analyzes the benefits by using new enzymes and prospects for future development.

  17. Demonstration of a silicon nitride attrition mill for production of fine pure Si and Si3N4 powders

    NASA Technical Reports Server (NTRS)

    Herbell, T. P.; Glasgow, T. K.; Orth, N. W.

    1984-01-01

    To avoid metallic impurities normally introduced by milling ceramic powders in conventional steel hardware, an attrition mill (high-energy stirred ball mill) was constructed with the wearing parts (mill body, stirring arms, and media) made from silicon nitride. Commercial silicon and Si3N4 powders were milled to fine uniform particles with only minimal contamination - primarily from wear of the sintered Si3N4 media.

  18. Valorization of industrial waste and by-product streams via fermentation for the production of chemicals and biopolymers.

    PubMed

    Koutinas, Apostolis A; Vlysidis, Anestis; Pleissner, Daniel; Kopsahelis, Nikolaos; Lopez Garcia, Isabel; Kookos, Ioannis K; Papanikolaou, Seraphim; Kwan, Tsz Him; Lin, Carol Sze Ki

    2014-04-21

    The transition from a fossil fuel-based economy to a bio-based economy necessitates the exploitation of synergies, scientific innovations and breakthroughs, and step changes in the infrastructure of chemical industry. Sustainable production of chemicals and biopolymers should be dependent entirely on renewable carbon. White biotechnology could provide the necessary tools for the evolution of microbial bioconversion into a key unit operation in future biorefineries. Waste and by-product streams from existing industrial sectors (e.g., food industry, pulp and paper industry, biodiesel and bioethanol production) could be used as renewable resources for both biorefinery development and production of nutrient-complete fermentation feedstocks. This review focuses on the potential of utilizing waste and by-product streams from current industrial activities for the production of chemicals and biopolymers via microbial bioconversion. The first part of this review presents the current status and prospects on fermentative production of important platform chemicals (i.e., selected C2-C6 metabolic products and single cell oil) and biopolymers (i.e., polyhydroxyalkanoates and bacterial cellulose). In the second part, the qualitative and quantitative characteristics of waste and by-product streams from existing industrial sectors are presented. In the third part, the techno-economic aspects of bioconversion processes are critically reviewed. Four case studies showing the potential of case-specific waste and by-product streams for the production of succinic acid and polyhydroxyalkanoates are presented. It is evident that fermentative production of chemicals and biopolymers via refining of waste and by-product streams is a highly important research area with significant prospects for industrial applications.

  19. Additives initiate selective production of chemicals from biomass pyrolysis.

    PubMed

    Leng, Shuai; Wang, Xinde; Wang, Lei; Qiu, Huizhe; Zhuang, Guilin; Zhong, Xing; Wang, Jianguo; Ma, Fengyun; Liu, Jingmei; Wang, Qiang

    2014-03-01

    To improve chemicals selectivity under low temperature, a new method that involves the injection of additives into biomass pyrolysis is introduced. This method allows biomass pyrolysis to achieve high selectivity to chemicals under low temperature (300°C), while nothing was obtained in typical pyrolysis under 300°C. However, by using the new method, the first liquid drop emerged at the interval between 140°C and 240°C. Adding methanol to mushroom scrap pyrolysis obtained high selectivity to acetic acid (98.33%), while adding ethyl acetate gained selectivity to methanol (65.77%) in bagasse pyrolysis and to acetone (72.51%) in corncob pyrolysis. Apart from basic chemicals, one high value-added chemical (2,3-dihydrobenzofuran) was also detected, which obtained the highest selectivity (10.33%) in corncob pyrolysis through the addition of ethyl acetate. Comparison of HZSM-5 and CaCO3 catalysis showed that benzene emerged in the liquid because of the larger degree of cracking and hydrodeoxygenation over HZSM-5.

  20. Energy efficiency increase in a chemical production site.

    PubMed

    Keller, Urs; Jucker, Walter

    2013-01-01

    Sustainability has become a key factor for the chemical industry. One element of sustainability is energy efficiency in manufacturing processes. This article illustrates the strategic energy initiatives of a leading global operating company and the implementation of its elements into practice. Some successful energy-saving projects are highlighted.

  1. Glycation products in infant formulas: chemical, analytical and physiological aspects.

    PubMed

    Pischetsrieder, Monika; Henle, Thomas

    2012-04-01

    Infant formulas are milk-based products, which are adapted to the composition of human milk. To ensure microbiological safety and long shelf life, infant formulas usually undergo rigid heat treatment. As a consequence of the special composition and the heat regimen, infant formulas are more prone to thermally induced degradation reactions than regular milk products. Degradation reactions observed during milk processing comprise lactosylation yielding the Amadori product lactulosyllysine, the formation of advanced glycation end products (AGEs), and protein-free sugar degradation products, as well as protein or lipid oxidation. Several methods have been developed to estimate the heat impact applied during the manufacturing of infant formulas, including indirect methods such as fluorescence analysis as well as the analysis of defined reaction products. Most studies confirm a higher degree of damage in infant formulas compared to regular milk products. Differences between various types of infant formulas, such as liquid, powdered or hypoallergenic formulas depend on the analyzed markers and brands. A considerable portion of protein degradation products in infant formulas can be avoided when process parameters and the quality of the ingredients are carefully controlled. The nutritional consequences of thermal degradation products in infant formulas are largely unknown.

  2. Estrogenic chemicals often leach from BPA-free plastic products that are replacements for BPA-containing polycarbonate products

    PubMed Central

    2014-01-01

    Background Xenobiotic chemicals with estrogenic activity (EA), such as bisphenol A (BPA), have been reported to have potential adverse health effects in mammals, including humans, especially in fetal and infant stages. Concerns about safety have caused many manufacturers to use alternatives to polycarbonate (PC) resins to make hard and clear, reusable, plastic products that do not leach BPA. However, no study has focused on whether such BPA-free PC-replacement products, chosen for their perceived higher safety, especially for babies, also release other chemicals that have EA. Methods We used two, well-established, mammalian cell-based, assays (MCF-7 and BG1Luc) to assess the EA of chemicals that leached into over 1000 saline or ethanol extracts of 50 unstressed or stressed (autoclaving, microwaving, and UV radiation) BPA-free PC-replacement products. An EA antagonist, ICI 182,780, was used to confirm that agonist activity in leachates was due to chemicals that activated the mammalian estrogen receptor. Results Many unstressed and stressed, PC-replacement-products made from acrylic, polystyrene, polyethersulfone, and Tritan™ resins leached chemicals with EA, including products made for use by babies. Exposure to various forms of UV radiation often increased the leaching of chemicals with EA. In contrast, some BPA-free PC-replacement products made from glycol-modified polyethylene terephthalate or cyclic olefin polymer or co-polymer resins did not release chemicals with detectable EA under any conditions tested. Conclusions This hazard assessment survey showed that many BPA-free PC- replacement products still leached chemicals having significant levels of EA, as did BPA-containing PC counterparts they were meant to replace. That is, BPA-free did not mean EA-free. However, this study also showed that some PC-replacement products did not leach chemicals having significant levels of EA. That is, EA-free PC-replacement products could be made in commercial quantities at

  3. Estrogenic chemicals often leach from BPA-free plastic products that are replacements for BPA-containing polycarbonate products.

    PubMed

    Bittner, George D; Yang, Chun Z; Stoner, Matthew A

    2014-05-28

    Xenobiotic chemicals with estrogenic activity (EA), such as bisphenol A (BPA), have been reported to have potential adverse health effects in mammals, including humans, especially in fetal and infant stages. Concerns about safety have caused many manufacturers to use alternatives to polycarbonate (PC) resins to make hard and clear, reusable, plastic products that do not leach BPA. However, no study has focused on whether such BPA-free PC-replacement products, chosen for their perceived higher safety, especially for babies, also release other chemicals that have EA. We used two, well-established, mammalian cell-based, assays (MCF-7 and BG1Luc) to assess the EA of chemicals that leached into over 1000 saline or ethanol extracts of 50 unstressed or stressed (autoclaving, microwaving, and UV radiation) BPA-free PC-replacement products. An EA antagonist, ICI 182,780, was used to confirm that agonist activity in leachates was due to chemicals that activated the mammalian estrogen receptor. Many unstressed and stressed, PC-replacement-products made from acrylic, polystyrene, polyethersulfone, and Tritan™ resins leached chemicals with EA, including products made for use by babies. Exposure to various forms of UV radiation often increased the leaching of chemicals with EA. In contrast, some BPA-free PC-replacement products made from glycol-modified polyethylene terephthalate or cyclic olefin polymer or co-polymer resins did not release chemicals with detectable EA under any conditions tested. This hazard assessment survey showed that many BPA-free PC- replacement products still leached chemicals having significant levels of EA, as did BPA-containing PC counterparts they were meant to replace. That is, BPA-free did not mean EA-free. However, this study also showed that some PC-replacement products did not leach chemicals having significant levels of EA. That is, EA-free PC-replacement products could be made in commercial quantities at prices that compete with PC

  4. High-throughput exposure modeling to support prioritization of chemicals in personal care products.

    PubMed

    Csiszar, Susan A; Ernstoff, Alexi S; Fantke, Peter; Meyer, David E; Jolliet, Olivier

    2016-11-01

    We demonstrate the application of a high-throughput modeling framework to estimate exposure to chemicals used in personal care products (PCPs). As a basis for estimating exposure, we use the product intake fraction (PiF), defined as the mass of chemical taken by an individual or population per mass of a given chemical used in a product. We calculated use- and disposal- stage PiFs for 518 chemicals for five PCP archetypes. Across all product archetypes the use- and disposal- stage PiFs ranged from 10(-5) to 1 and 0 to 10(-3), respectively. There is a distinction between the use-stage PiF for leave-on and wash-off products which had median PiFs of 0.5 and 0.02 across the 518 chemicals, respectively. The PiF is a function of product characteristics and physico-chemical properties and is maximized when skin permeability is high and volatility is low such that there is no competition between skin and air losses from the applied product. PCP chemical contents (i.e. concentrations) were available for 325 chemicals and were combined with PCP usage characteristics and PiF yielding intakes summed across a demonstrative set of products ranging from 10(-8)-30 mg/kg/d, with a median of 0.1 mg/kg/d. The highest intakes were associated with body lotion. Bioactive doses derived from high-throughput in vitro toxicity data were combined with the estimated PiFs to demonstrate an approach to estimate bioactive equivalent chemical content and to screen chemicals for risk. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Considerations of the chemical biology of microbial natural products provide an effective drug discovery strategy.

    PubMed

    Choi, Hyukjae; Oh, Dong-Chan

    2015-09-01

    Conventional approaches to natural product drug discovery rely mainly on random searches for bioactive compounds using bioassays. These traditional approaches do not incorporate a chemical biology perspective. Searching for bioactive molecules using a chemical and biological rationale constitutes a powerful search paradigm. Here, the authors review recent examples of the discovery of bioactive natural products based on chemical and biological interactions between hosts and symbionts, and propose this method provides a more effective means of exploring natural chemical diversity and eventually of discovering new drugs.

  6. Title III section 313 release reporting guidance: Estimating chemical releases from paper and paperboard production

    SciTech Connect

    Not Available

    1988-02-01

    Facilities engaged in paper and paperboard production may be required to report annually any releases to the environment of certain chemicals regulated under Section 313, Title III, of the Superfund Amendments and Reauthorization Act (SARA) of 1986. The document has been developed to assist those engaged in paper and paperboard production in the completion of Part III (Chemical Specific Information) of the Toxic Chemical Release Inventory Reporting Form. Included herein is general information on toxic chemicals used and process wastes generated, along with several examples to demonstrate the types of data needed and various methodologies available for estimating releases.

  7. Harvesting and utilizing wood and wood by-products for chemicals

    SciTech Connect

    Nelson, A.W.

    1980-01-01

    Wood has been a source of chemicals since the beginning of recorded history. Naval Stores, chestnut for tannic acid, and hardwood chemical wood for destructive distillation producing charcoal, methanol and acetic acid are a few examples. In recent years, wood for the production of pulp, paper and chemical cellulose is now the largest chemical feedstock component. Current awareness of the limitations on the supply of natural gas and petroleum available to us brings to mind the fact that many of the products derived from petroleum can also be derived from wood.

  8. Consumer products as sources of chemical exposures to children: case study of triclosan.

    PubMed

    Ginsberg, Gary L; Balk, Sophie J

    2016-04-01

    Consumer products are often overlooked as sources of children's exposures to toxic chemicals. Various regulatory bodies have developed lists of chemicals of concern that can be found in products contacted by children. However, this information has not been summarized for health practitioners. This review organizes such chemicals and products into four categories, with the antibacterial agent triclosan used to illustrate the potential risks to children from a common ingredient in consumer products. Biomonitoring, house dust, indoor air, and product testing document children's exposures to a wide variety of chemicals. An increasing number of epidemiology studies have shown associations between these exposures and health effects in children. Triclosan is an example of a chemical contained in high contact products (e.g., soaps, lotions, and toothpaste) not necessarily designed for children. Triclosan exposure in children has been associated with increased responsiveness to airway allergens, with it also capable of endocrine disruption. However, the utility and necessity of this chemical in consumer products has not been demonstrated in most cases. Triclosan and the other examples provided show that a changing marketplace with little regulatory oversight of chemical uses can lead to unanticipated exposures and potential health risks to children.

  9. Coupled near-field and far-field exposure assessment framework for chemicals in consumer products.

    PubMed

    Fantke, Peter; Ernstoff, Alexi S; Huang, Lei; Csiszar, Susan A; Jolliet, Olivier

    2016-09-01

    Humans can be exposed to chemicals in consumer products through product use and environmental emissions over the product life cycle. Exposure pathways are often complex, where chemicals can transfer directly from products to humans during use or exchange between various indoor and outdoor compartments until sub-fractions reach humans. To consistently evaluate exposure pathways along product life cycles, a flexible mass balance-based assessment framework is presented structuring multimedia chemical transfers in a matrix of direct inter-compartmental transfer fractions. By matrix inversion, we quantify cumulative multimedia transfer fractions and exposure pathway-specific product intake fractions defined as chemical mass taken in by humans per unit mass of chemical in a product. Combining product intake fractions with chemical mass in the product yields intake estimates for use in life cycle impact assessment and chemical alternatives assessment, or daily intake doses for use in risk-based assessment and high-throughput screening. Two illustrative examples of chemicals used in personal care products and flooring materials demonstrate how this matrix-based framework offers a consistent and efficient way to rapidly compare exposure pathways for adult and child users and for the general population. This framework constitutes a user-friendly approach to develop, compare and interpret multiple human exposure scenarios in a coupled system of near-field ('user' environment), far-field and human intake compartments, and helps understand the contribution of individual pathways to overall human exposure in various product application contexts to inform decisions in different science-policy fields for which exposure quantification is relevant. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Evaluation of the degree of mixing of combinations of dry syrup, powder, and fine granule products in consideration of particle size distribution using near infrared spectrometry.

    PubMed

    Yamamoto, Yoshihisa; Suzuki, Toyofumi; Matsumoto, Mika; Ohtani, Michiteru; Hayano, Shuichi; Fukami, Toshiro; Tomono, Kazuo

    2012-01-01

    We used near infrared (NIR) spectroscopy to evaluate the degree of mixing of blended dry syrup (DS) products whose particle sizes are not specified in the Revised 16th Edition of the Japanese Pharmacopoeia, and also evaluated the degree of mixing when powder products or fine granule products were added to DS products. The data obtained were used to investigate the relationship between the particle size distributions of the products studied and the degree of mixing. We found that the particle size distribution characteristics of the 15 DS products studied can be broadly classified into 5 types. Combinations of frequently prescribed products were selected to represent 4 of the 5 particle size distribution types and were blended with a mortar and pestle. The coefficient of variation (CV) decreased as the percent mass of Asverin® Dry Syrup 2% (Asverin-DS) increased in blends of Periactin® Powder 1% (Periactin) and Asverin-DS, indicating an improved degree of mixing (uniformity). In contrast, in blends of Periactin and Mucodyne® DS 33.3%, mixing a combination at a 1:1 mass ratio 40 times resulted in a CV of 20%. Other mixing frequencies and mass ratios resulted in a CV by 50% to 70%, indicating a very poor degree of mixing (poor uniformity). These results suggest that when combining different DSs, or a DS with a powder or fine granule product, the blending obtained with a mortar and pestle improves as the particle size distributions of the components approach each other and as the ranges of the distributions narrow.

  11. Capturing Biological Activity in Natural Product Fragments by Chemical Synthesis

    PubMed Central

    Crane, Erika A.

    2016-01-01

    Abstract Natural products have had an immense influence on science and have directly led to the introduction of many drugs. Organic chemistry, and its unique ability to tailor natural products through synthesis, provides an extraordinary approach to unlock the full potential of natural products. In this Review, an approach based on natural product derived fragments is presented that can successfully address some of the current challenges in drug discovery. These fragments often display significantly reduced molecular weights, reduced structural complexity, a reduced number of synthetic steps, while retaining or even improving key biological parameters such as potency or selectivity. Examples from various stages of the drug development process up to the clinic are presented. In addition, this process can be leveraged by recent developments such as genome mining, antibody–drug conjugates, and computational approaches. All these concepts have the potential to identify the next generation of drug candidates inspired by natural products. PMID:26833854

  12. Capturing Biological Activity in Natural Product Fragments by Chemical Synthesis.

    PubMed

    Crane, Erika A; Gademann, Karl

    2016-03-14

    Natural products have had an immense influence on science and have directly led to the introduction of many drugs. Organic chemistry, and its unique ability to tailor natural products through synthesis, provides an extraordinary approach to unlock the full potential of natural products. In this Review, an approach based on natural product derived fragments is presented that can successfully address some of the current challenges in drug discovery. These fragments often display significantly reduced molecular weights, reduced structural complexity, a reduced number of synthetic steps, while retaining or even improving key biological parameters such as potency or selectivity. Examples from various stages of the drug development process up to the clinic are presented. In addition, this process can be leveraged by recent developments such as genome mining, antibody-drug conjugates, and computational approaches. All these concepts have the potential to identify the next generation of drug candidates inspired by natural products.

  13. Chemical conversion of energetic materials to higher value products

    SciTech Connect

    Mitchell, A. R., LLNL

    1998-05-01

    The objective of this project is to develop new and innovative solutions for the disposal of surplus energetic materials. Disposal through open burning/open detonation (OB/OD) is less attractive today due to environmental, cost and safety concerns. We are examining the use of military high explosives as raw materials for the production of higher value products useful in civilian and military applications. We have developed scenarios where Explosive D and TNT can be used as raw materials for industrial processes to produce higher value products. 1,2 The use of Explosive D as a precursor to picramide, an intermediate potentially useful for the production of many higher value products, is illustrated in Figure 1.

  14. Trends in Exposure to Chemicals in Personal Care and Consumer Products.

    PubMed

    Calafat, Antonia M; Valentin-Blasini, Liza; Ye, Xiaoyun

    2015-12-01

    Synthetic organic chemicals can be used in personal care and consumer products. Data on potential human health effects of these chemicals are limited-sometimes even contradictory-but because several of these chemicals are toxic in experimental animals, alternative compounds are entering consumer markets. Nevertheless, limited information exists on consequent exposure trends to both the original chemicals and their replacements. Biomonitoring (measuring concentrations of chemicals or their metabolites in people) provides invaluable information for exposure assessment. We use phthalates and bisphenol A-known industrial chemicals-and organophosphate insecticides as case studies to show exposure trends to these chemicals and their replacements (e.g., other phthalates, non-phthalate plasticizers, various bisphenols, pyrethroid insecticides) among the US general population. We compare US trends to national trends from Canada and Germany. Exposure to the original compounds is still prevalent among these general populations, but exposures to alternative chemicals may be increasing.

  15. Chemical proteomics approaches for identifying the cellular targets of natural products.

    PubMed

    Wright, M H; Sieber, S A

    2016-05-04

    Covering: 2010 up to 2016Deconvoluting the mode of action of natural products and drugs remains one of the biggest challenges in chemistry and biology today. Chemical proteomics is a growing area of chemical biology that seeks to design small molecule probes to understand protein function. In the context of natural products, chemical proteomics can be used to identify the protein binding partners or targets of small molecules in live cells. Here, we highlight recent examples of chemical probes based on natural products and their application for target identification. The review focuses on probes that can be covalently linked to their target proteins (either via intrinsic chemical reactivity or via the introduction of photocrosslinkers), and can be applied "in situ" - in living systems rather than cell lysates. We also focus here on strategies that employ a click reaction, the copper-catalysed azide-alkyne cycloaddition reaction (CuAAC), to allow minimal functionalisation of natural product scaffolds with an alkyne or azide tag. We also discuss 'competitive mode' approaches that screen for natural products that compete with a well-characterised chemical probe for binding to a particular set of protein targets. Fuelled by advances in mass spectrometry instrumentation and bioinformatics, many modern strategies are now embracing quantitative proteomics to help define the true interacting partners of probes, and we highlight the opportunities this rapidly evolving technology provides in chemical proteomics. Finally, some of the limitations and challenges of chemical proteomics approaches are discussed.

  16. Chemical proteomics approaches for identifying the cellular targets of natural products

    PubMed Central

    Sieber, S. A.

    2016-01-01

    Covering: 2010 up to 2016 Deconvoluting the mode of action of natural products and drugs remains one of the biggest challenges in chemistry and biology today. Chemical proteomics is a growing area of chemical biology that seeks to design small molecule probes to understand protein function. In the context of natural products, chemical proteomics can be used to identify the protein binding partners or targets of small molecules in live cells. Here, we highlight recent examples of chemical probes based on natural products and their application for target identification. The review focuses on probes that can be covalently linked to their target proteins (either via intrinsic chemical reactivity or via the introduction of photocrosslinkers), and can be applied “in situ” – in living systems rather than cell lysates. We also focus here on strategies that employ a click reaction, the copper-catalysed azide–alkyne cycloaddition reaction (CuAAC), to allow minimal functionalisation of natural product scaffolds with an alkyne or azide tag. We also discuss ‘competitive mode’ approaches that screen for natural products that compete with a well-characterised chemical probe for binding to a particular set of protein targets. Fuelled by advances in mass spectrometry instrumentation and bioinformatics, many modern strategies are now embracing quantitative proteomics to help define the true interacting partners of probes, and we highlight the opportunities this rapidly evolving technology provides in chemical proteomics. Finally, some of the limitations and challenges of chemical proteomics approaches are discussed. PMID:27098809

  17. Characteristics and Influence of Biosmoke on the Fine-Particle Ionic Composition Measured in Asian Outflow during the Transport and Chemical Evolution Over the Pacific (TRACE-P) Experiment

    NASA Technical Reports Server (NTRS)

    Ma, Y.; Weber, R. J.; Lee, Y.-N.; Orsini, D. A.; Maxwell-Meier, K.; Thornton, D. C.; Bandy, A. R.; Clarke, A. D.; Blake, D. R.; Sachse, G. W.

    2003-01-01

    We investigate the sources, prevalence, and fine-particle inorganic composition of biosmoke over the western Pacific Ocean between 24 February and 10 April 2001. The analysis is based on highly time-resolved airborne measurements of gaseous and fine- particle inorganic chemical composition made during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment. At latitudes below approximately 25 deg. N, relatively pure biomass burning plumes of enhanced fine-particle potassium, nitrate, ammonium, light-absorbing aerosols, and CO concentrations were observed in plumes that back trajectories and satellite fire map data suggest originated from biomass burning in southeast Asia. Fine-particle water-soluble potassium (K+) is confirmed to be a unique biosmoke tracer, and its prevalence throughout the experiment indicates that approximately 20% of the TRACE-P Asian outflow plumes were influenced, to some extent, by biomass or biofuel burning emissions. At latitudes above 25 deg. N, highly mixed urban/industrial and biosmoke plumes, indicated by SO(sup 2, sub 4) and K+, were observed in 5 out of 53 plumes. Most plumes were found in the Yellow Sea and generally were associated with much higher fine-particle loadings than plumes lacking a biosmoke influence. The air mass back trajectories of these mixed plumes generally pass through the latitude range of between 34 deg. and 40 deg. N on the eastern China coast, a region that includes the large urban centers of Beijing and Tianjin. A lack of biomass burning emissions based on fire maps and high correlations between K+ and pollution tracers (e.g., S(sup 2, sub 4) suggest biofuel sources. Ratios of fine-particle potassium to sulfate are used to provide an estimate of relative contributions of biosmoke emissions to the mixed Asian plumes. The ratio is highly correlated with fine-particle volume (r(sup 2) = 0.85) and predicts that for the most polluted plume encounter in TRACE-P, approximately 60% of the

  18. Characteristics and Influence of Biosmoke on the Fine-Particle Ionic Composition Measured in Asian Outflow during the Transport and Chemical Evolution Over the Pacific (TRACE-P) Experiment

    NASA Technical Reports Server (NTRS)

    Ma, Y.; Weber, R. J.; Lee, Y.-N.; Orsini, D. A.; Maxwell-Meier, K.; Thornton, D. C.; Bandy, A. R.; Clarke, A. D.; Blake, D. R.; Sachse, G. W.

    2003-01-01

    We investigate the sources, prevalence, and fine-particle inorganic composition of biosmoke over the western Pacific Ocean between 24 February and 10 April 2001. The analysis is based on highly time-resolved airborne measurements of gaseous and fine- particle inorganic chemical composition made during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment. At latitudes below approximately 25 deg. N, relatively pure biomass burning plumes of enhanced fine-particle potassium, nitrate, ammonium, light-absorbing aerosols, and CO concentrations were observed in plumes that back trajectories and satellite fire map data suggest originated from biomass burning in southeast Asia. Fine-particle water-soluble potassium (K+) is confirmed to be a unique biosmoke tracer, and its prevalence throughout the experiment indicates that approximately 20% of the TRACE-P Asian outflow plumes were influenced, to some extent, by biomass or biofuel burning emissions. At latitudes above 25 deg. N, highly mixed urban/industrial and biosmoke plumes, indicated by SO(sup 2, sub 4) and K+, were observed in 5 out of 53 plumes. Most plumes were found in the Yellow Sea and generally were associated with much higher fine-particle loadings than plumes lacking a biosmoke influence. The air mass back trajectories of these mixed plumes generally pass through the latitude range of between 34 deg. and 40 deg. N on the eastern China coast, a region that includes the large urban centers of Beijing and Tianjin. A lack of biomass burning emissions based on fire maps and high correlations between K+ and pollution tracers (e.g., S(sup 2, sub 4) suggest biofuel sources. Ratios of fine-particle potassium to sulfate are used to provide an estimate of relative contributions of biosmoke emissions to the mixed Asian plumes. The ratio is highly correlated with fine-particle volume (r(sup 2) = 0.85) and predicts that for the most polluted plume encounter in TRACE-P, approximately 60% of the

  19. The Idaho Chemical Processing Plant Product Denitrator Upgrade

    SciTech Connect

    N /A

    1982-05-01

    The upgrade and redesign of a fluidized-bed denitrator for production of uranium trioxide from uranyl nitrate solution is discussed. The success of the project in improving process efficiency and personnel safety is also addressed based on subsequent operation.

  20. Distribution and leaching ability of some heavy metals in products of flotation processing of fine-grained coal slurries

    SciTech Connect

    Klika, Z.; Weiss, Z.; Lach, K.

    1994-12-31

    Coal from the Ostrava-Karvina mines is processed in 19 coal preparation plants, 6 of which are not equipped with flotation technology. Generally, all fine-grained coal is transported into sedimentary coal slurry ponds. Depending on processing technology, coal slurries contain from 5 to 95% coal matter. Sedimentary coal slurry ponds occupy large areas, deteriorate the landscape, and ar great sources of dust in a dry summer. Moreover, some components from coal slurries scan be leached and can penetrate into underground water. This research project sampled 13 coal slurry ponds to determine the composition of coal slurries, the distribution of some heavy metals in the flotation process, and leaching behavior.

  1. Biorefineries for the production of top building block chemicals and their derivatives.

    PubMed

    Choi, Sol; Song, Chan Woo; Shin, Jae Ho; Lee, Sang Yup

    2015-03-01

    Due to the growing concerns on the climate change and sustainability on petrochemical resources, DOE selected and announced the bio-based top 12 building blocks and discussed the needs for developing biorefinery technologies to replace the current petroleum based industry in 2004. Over the last 10 years after its announcement, many studies have been performed for the development of efficient technologies for the bio-based production of these chemicals and derivatives. Now, ten chemicals among these top 12 chemicals, excluding the l-aspartic acid and 3-hydroxybutyrolactone, have already been commercialized or are close to commercialization. In this paper, we review the current status of biorefinery development for the production of these platform chemicals and their derivatives. In addition, current technological advances on industrial strain development for the production of platform chemicals using micro-organisms will be covered in detail with case studies on succinic acid and 3-hydroxypropionic acid as examples.

  2. Development of biocatalysts for production of commodity chemicals from lignocellulosic biomass.

    PubMed

    Adsul, M G; Singhvi, M S; Gaikaiwari, S A; Gokhale, D V

    2011-03-01

    Lignocellulosic biomass is recognized as potential sustainable source for production of power, biofuels and variety of commodity chemicals which would potentially add economic value to biomass. Recalcitrance nature of biomass is largely responsible for the high cost of its conversion. Therefore, it is necessary to introduce some cost effective pretreatment processes to make the biomass polysaccharides easily amenable to enzymatic attack to release mixed fermentable sugars. Advancement in systemic biology can provide new tools for the development of such biocatalysts for sustainable production of commodity chemicals from biomass. Integration of functional genomics and system biology approaches may generate efficient microbial systems with new metabolic routes for production of commodity chemicals. This paper provides an overview of the challenges that are faced by the processes converting lignocellulosic biomass to commodity chemicals. The critical factors involved in engineering new microbial biocatalysts are also discussed with more emphasis on commodity chemicals. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Use of the Chemical Transformation Simulator as a Parameterization Tool for Modeling the Environmental Fate of Organic Chemicals and their Transformation Products

    EPA Science Inventory

    A Chemical Transformation Simulator is a web-based system for predicting transformation pathways and physicochemical properties of organic chemicals. Role in Environmental Modeling • Screening tool for identifying likely transformation products in the environment • Parameteri...

  4. Use of the Chemical Transformation Simulator as a Parameterization Tool for Modeling the Environmental Fate of Organic Chemicals and their Transformation Products

    EPA Science Inventory

    A Chemical Transformation Simulator is a web-based system for predicting transformation pathways and physicochemical properties of organic chemicals. Role in Environmental Modeling • Screening tool for identifying likely transformation products in the environment • Parameteri...

  5. Use of Natural Products as Chemical Library for Drug Discovery and Network Pharmacology

    PubMed Central

    Gu, Jiangyong; Gui, Yuanshen; Chen, Lirong; Yuan, Gu; Lu, Hui-Zhe; Xu, Xiaojie

    2013-01-01

    Background Natural products have been an important source of lead compounds for drug discovery. How to find and evaluate bioactive natural products is critical to the achievement of drug/lead discovery from natural products. Methodology We collected 19,7201 natural products structures, reported biological activities and virtual screening results. Principal component analysis was employed to explore the chemical space, and we found that there was a large portion of overlap between natural products and FDA-approved drugs in the chemical space, which indicated that natural products had large quantity of potential lead compounds. We also explored the network properties of natural product-target networks and found that polypharmacology was greatly enriched to those compounds with large degree and high betweenness centrality. In order to make up for a lack of experimental data, high throughput virtual screening was employed. All natural products were docked to 332 target proteins of FDA-approved drugs. The most potential natural products for drug discovery and their indications were predicted based on a docking score-weighted prediction model. Conclusions Analysis of molecular descriptors, distribution in chemical space and biological activities of natural products was conducted in this article. Natural products have vast chemical diversity, good drug-like properties and can interact with multiple cellular target proteins. PMID:23638153

  6. Research on human reliability of large-scale chemical production system

    NASA Astrophysics Data System (ADS)

    Miao, Yongchun; Kang, Rongxue

    2017-05-01

    Based on the elaboration of the theoretical basis of large-scale chemical production system and human reliability analysis(HRA), this paper builds the evaluation model of human reliability for large-scale production system by using analytic hierarchy process and fuzzy evaluation method, and deeply understands the importance and the internal mechanism of the human reliability elements in large-scale chemical production system. Moreover, with the specific production system to construct and analyze the model, this paper reveals the correlation between human reliability and the production system, and verifies the validity of the model. The results show that a large-scale chemical production system has a membership degree of 0.360, and its human reliability belongs to the moderate level.

  7. Engineering an Obligate Photoautotrophic Cyanobacterium to Utilize Glycerol for Growth and Chemical Production.

    PubMed

    Kanno, Masahiro; Atsumi, Shota

    2017-01-20

    Cyanobacteria have attracted much attention as a means to directly recycle carbon dioxide into valuable chemicals that are currently produced from petroleum. However, the titers and productivities achieved are still far below the level required in industry. To make a more industrially applicable production scheme, glycerol, a byproduct of biodiesel production, can be used as an additional carbon source for photomixotrophic chemical production. Glycerol is an ideal candidate due to its availability and low cost. In this study, we found that a heterologous glycerol respiratory pathway enabled Synechococcus elongatus PCC 7942 to utilize extracellular glycerol. The engineered strain produced 761 mg/L of 2,3-butanediol in 48 h with a 290% increase over the control strain under continuous light conditions. Glycerol supplementation also allowed for continuous cell growth and 2,3-butanediol production in diurnal light conditions. These results highlight the potential of glycerol as an additional carbon source for photomixotrophic chemical production in cyanobacteria.

  8. Study to establish cost projections for production of Redox chemicals

    NASA Technical Reports Server (NTRS)

    Walther, J. F.; Greco, C. C.; Rusinko, R. N.; Wadsworth, A. L., III

    1982-01-01

    A cost study of four proposed manufacturing processes for redox chemicals for the NASA REDOX Energy Storage System yielded favorable selling prices in the range $0.99 to $1.91/kg of chromic chloride, anhydrous basis, including ferrous chloride. The prices corresponded to specific energy storage costs from under $9 to $17/kWh. A refined and expanded cost analysis of the most favored process yielded a price estimate corresponding to a storage cost of $11/kWh. The findings supported the potential economic viability of the NASA REDOX system.

  9. Chemical test for mammalian feces in grain products: collaborative study.

    PubMed

    Gerber, H R

    1989-01-01

    A collaborative study was conducted to validate the use of the AOAC alkaline phosphatase method for mammalian feces in corn meal, 44.B01-44.B06, for 7 additional products: brown rice cream, oat bran, grits, semolina, pasta flour, farina, and barley plus (a mixture of barley, oat bran, and brown rice). The proposed method determines the presence of alkaline phosphatase, an enzyme contained in mammalian feces, by using phenolphthalein diphosphate as the enzyme substrate in a test agar medium. Fecal matter is separated from the grain products by specific gravity differences in 1% test agar. As the product is distributed on liquid test agar, fecal fragments float while the grain products sink. The alkaline phosphatase cleaves phosphate radicals from phenolphthalein diphosphate, generating free phenolphthalein, which produces a pink to red-purple color around the fecal particles in the previously colorless medium. Collaborators' recovery averages ranged from 21.7 particles (72.3%) for oat bran to 25.3 particles (84.3%) for semolina at the 30 particle spike level. Overall average background was 0.4 positive reactions per food type. The collaborators reported that the method was quick, simple, and easy to use. The method has been approved interim official first action for all 7 grain products.

  10. Cyanobacterium sp. host cell and vector for production of chemical compounds in Cyanobacterial cultures

    SciTech Connect

    Piven, Irina; Friedrich, Alexandra; Duhring, Ulf; Uliczka, Frank; Baier, Kerstin; Inaba, Masami; Shi, Tuo; Wang, Kui; Enke, Heike; Kramer, Dan

    2016-04-19

    A cyanobacterial host cell, Cyanobacterium sp., that harbors at least one recombinant gene for the production of a chemical compounds is provided, as well as vectors derived from an endogenous plasmid isolated from the cell.

  11. Clean Air Act Standards and Guidelines for Chemical Production and Distribution

    EPA Pesticide Factsheets

    This page contains the stationary sources of air pollution for the chemical production & distribution industries, and their corresponding air pollution regulations. To learn more about the regulations for each industry, just click on the links below.

  12. Cyanobacterium sp. host cell and vector for production of chemical compounds in cyanobacterial cultures

    DOEpatents

    Piven, Irina; Friedrich, Alexandra; Duhring, Ulf; Uliczka, Frank; Baier, Kerstin; Inaba, Masami; Shi, Tuo; Wang, Kui; Enke, Heike; Kramer, Dan

    2014-09-30

    A cyanobacterial host cell, Cyanobacterium sp., that harbors at least one recombinant gene for the production of a chemical compounds is provided, as well as vectors derived from an endogenous plasmid isolated from the cell.

  13. Prediction of Hydrolysis Products of Organic Chemicals under Environmental pH Conditions

    EPA Science Inventory

    Cheminformatics-based software tools can predict the molecular structure of transformation products using a library of transformation reaction schemes. This paper presents the development of such a library for abiotic hydrolysis of organic chemicals under environmentally relevant...