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Sample records for bioorganometallic chemistry biocatalytic

  1. Bioorganometallic chemistry: biocatalytic oxidation reactions with biomimetic nad+/nadh co-factors and [cp*rh(bpy)h]+ for selective organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, Jochen; Hollman, Frank; Ho, The Vinh; Schnyder, Adrian; Fish, Richard H.; Schmid, Andreas

    2004-03-09

    The biocatalytic, regioselective hydroxylation of 2-hydroxybiphenyl to the corresponding catechol was accomplished utilizing the monooxygenase 2-hydroxybiphenyl 3-monooxygenase (HbpA). The necessary natural nicotinamide adenine dinucleotide (NAD{sup +}) co-factor for this biocatalytic process was replaced by a biomimetic co-factor, N-benzylnicotinamide bromide, 1a. The interaction between the flavin (FAD) containing HbpA enzyme and the corresponding biomimetic NADH compound, N-benzyl-1,4-dihdronicotinamide, 1b, for hydride transfers, was shown to readily occur. The in situ recycling of the reduced NADH biomimic 1b from 1a was accomplished with [Cp*Rh(bpy)H](Cl); however, productive coupling of this regeneration reaction to the enzymatic hydroxylation reaction was not totally successful, due to a deactivation process concerning the HbpA enzyme peripheral groups; i.e., -SH or -NH{sub 2} possibly reacting with the precatalyst, [Cp*Rh(bpy)(H{sub 2}O)](Cl){sub 2}, and thus inhibiting the co-factor regeneration process. The deactivation mechanism was studied, and a promising strategy of derivatizing these peripheral -SH or -NH{sub 2} groups with a polymer containing epoxide was successful in circumventing the undesired interaction between HbpA and the precatalyst. This latter strategy allowed tandem co-factor regeneration using 1a or 2a, [Cp*Rh(bpy)(H2O)](Cl){sub 2}, and formate ion, in conjunction with the polymer bound, FAD containing HbpA enzyme to provide the catechol product.

  2. Organometallic and Bioorganometallic Chemistry - Ferrocene and Metal Carbonyls

    Directory of Open Access Journals (Sweden)

    Čakić Semenčić, M.

    2011-02-01

    -substituted products. Owing to the low barrier to internal rotation around Cp-Fe-Cp axis (ω torsion angle ferrocene is characterized by D5d-symmetrical staggered and D5h-symetrical eclipsed forms. In the appropriately substituted ferrocenes, deviation from Cp coplanarity (tilt angle Θ may occur as well; e. g. ferrocenophanes are derivatives in which homo- or heteroatomic bridges spanned two Cp rings, causing appreciable deformations of ferrocene molecule (ω=0–26°; Θ=9–24°. A characteristic development of the science in the new age has been the gradual merging of what were once separate research disciplines. In such a way, on the border between classical organic and inorganic chemistry (long ago organometallic chemistry was established and in the last decades "hybridization" of biology (biochemistry and organometallic chemistry has resulted in the appearance of bioorganometallic chemistry. In short, this new discipline deals with conjugates of organometallics with biomolecules (DNA, PNA, carbohydrates, steroids, amino acids, peptides.... The principal fields of research activity in bioorganometallic chemistry are therapy, bioanalysis (sensors, molecular recognition in aqueous medium, enzymes (proteins, peptides, toxicology and environment.This article reviews only a few (interesting examples out of the immense number of bioorganometallics (classes. Many bioorganometallic drugs showed improved bioactivity in comparison with their classical anticancer and antimalarial analogues (e. g. tamoxifene → hydroxyferrocifene; chloroquine → ferroquine. Organometallic bioprobes are the molecules incorporating organometallic responding components (e. g. metal carbonyls. In the appropriately designed devices, these "molecular sensors" read out the information that is available from the molecular recognition events by FT-IR spectroscopy. Electrochemically active bioorganometallics (e. g. probes containing ferrocene are used in biosensors for detection of DNA, glucose in blood, etc. The

  3. Organometallic and Bioorganometallic Chemistry – Ferrocene Amino Acids

    Directory of Open Access Journals (Sweden)

    Barišić, L.

    2012-01-01

    Full Text Available This article is the second part of a series dealing with organometallic and bioorganometallic chemistry. In the first part of this series a short review on the history and development of these disciplines was given, emphasizing the importance and scope of bioorganometallic chemistry as a new field dealing with conjugates of organometallics and biomolecules (DNA, PNA, amino acids, peptides.... From the variety of biorganometallics, syntheses and properties of simple conjugates of ferrocene with natural amino acids/peptides were elaborated inter alia. This material is the basis for the second part in which ferrocene amino acids are described. The introduction presents nonproteinogenic alicyclic and aromatic amino acids as the models for the title compounds. Naturally occurring amino acids labelled with ferrocene moiety mostly retain properties of the biomolecules included. Contrary to these ω-ferrocenylamino acids, one could imagine specific amino acids with inserted ferrocene core belonging to either homo- or heterodisubstituted type. The central part of this article is devoted to our investigations of the second type - H2N-(CH2m-Fn-(CH2n-COOH. The general rational procedure for synthesis of these compounds and of their N- and/or C-protected derivatives via the azide intermediates N3-CO-(CH2m- Fn-(CH2n-COOMe has been described. In the solid state derivatives of ferrocene amino acids contain intermolecular hydrogen bonds giving dimeric structures, three-dimensional networks or endless helical chains. The solutions of homologues Ac-NH-(CH2m-Fn-(CH2n-COOMe in nonpolar solvents are dominated by open form conformers. Compounds containing 2–3 ferrocene cores connected by amide, imide and oxalamide spacers were prepared by oligomerization of 1'-aminoferrocene-1-carboxylic acid (Fca or by its condensation with the appropriate reagents. Similar to natural amino acids, ferrocene amino acids are water-soluble substances with high melting points

  4. Fundamental and Applied Bioorganometallic Chemistry of Technetium and Rhenium

    International Nuclear Information System (INIS)

    Site directed accumulation is the base for therapy and imaging with inorganic medicinal compounds. To match selectively the structural properties of receptors, the topology of targeting complexes must be flexible and easily adaptable. For in vivo application, kinetic stability is desirable and in an advanced design, the complex itself can become part of the structure to be recognized by the receptor (3D structural space occupation concept).1 To match these requirements, we introduced the fac-{99mTcI(CO)3}+ building block many years ago. Many different complexes with this core were subjected to targeting studies and the organometallic chemistry of Tc developed rapidly beyond designs for molecular imaging. Some prominent examples will give insight into their structures and activities for molecular imaging. For complementing the fac-{99mTcI(CO)3}+ tag, we switched from low- to high-valent complexes. The isolobal fac-{99mTcVII(O)3}+ building block was introduced.2 Preparation of TcVII complexes is an example about how research is translated to routinely applicable conditions. For proceeding towards theranostics, homologous complexes with Re for therapy and with 99mTc complexes for imaging are mandatory. A new synthetic approach enabled the preparation of cyclopentadienyl complexes of both elements and based on pharmaceutically active lead structures.3 Newly introduced bis-arene complexes scopes at using these structures in analogy to ferrocene.4 The presentation exemplifies how questions from, ultimately practical, application lead to basic developments. Unexpected results in turn influence the discovery of new imaging and therapeutic agents.5 (1) Meggers, E. Curr. Opin. Chem. Biol. 2007, 11, 287. (2) Braband, H.; Tooyama, Y.; Fox, T.; Alberto, R. Chem. Eur. J. 2009, 15, 633. (3) Can, D.; Spingler, B.; Schmutz, P.; Mendes, F.; Raposinho, P.; Fernandes, C.; Carta, F.; Innocenti, A.; Santos, I.; Supuran, C. T.; Alberto, R. Angew. Chem. Int. Edit. 2012, 51, 3354. (4) Benz

  5. III. Organometallic and Bioorganometallic Chemistry - Ferrocene Peptides

    Directory of Open Access Journals (Sweden)

    Kovačević, M.

    2012-02-01

    Full Text Available This paper is devoted to the bioconjugates of ferrocene with naturally occuring amino acids/peptides - mostly dealing with authors' results accompanied, to a lesser degree, by the relevant literature data. Chapter 2 deals with natural peptides and peptidomimetics, mainly focusing on α-helix and β pleated sheet (as the most important elements of peptide secondary and tertiary structure, and artificial β-sheets nucleated by non-amino acid turn inducers. Chapter 3 describes peptides generated from ferrocenecarboxylic acid and ferroceneamine, as well as with the bioconjugates of heteroannulary substituted ferrocene-1,1'-dicarboxylic acid (Fcd and ferrocene-1,1'-diamine (Fcda. Chapter 4 elaborates authors' papers about peptides based on 1'-aminoferrocene-1-carboxylic acid (Fca. Chapter 5 is devoted to the new monosubstituted Fcd and Fcda conjugates with amino acids, while Chapter 6 describes our publications in the field of very topical peptidomimetics - ferrocene ureidopeptides and β peptides. Conformational analysis of the newly prepared ferrocene bioconjugates in solution and solid state was performed by means of spectroscopic methods (CD, IR, 1D- NMR, 2D-NMR, v. r. NMR, and temperature and concentration dependent NMR and DFT calculations.

  6. Biocatalytic conversion of epoxides

    NARCIS (Netherlands)

    de Vries, Erik; Janssen, DB

    2003-01-01

    Epoxides are attractive intermediates for producing chiral compounds. Important biocatalytic reactions involving epoxides include epoxide hydrolase mediated kinetic resolution, leading to the formation of diols and enantiopure remaining substrates, and enantioconvergent enzymatic hydrolysis, which g

  7. Sustainable Biocatalytic Biodiesel Production

    DEFF Research Database (Denmark)

    Güzel, Günduz

    As part of his PhD studies, Gündüz Güzel examined the thermodynamics of reactions involved in biocatalytic biodiesel production processes, with a specific focus on phase equilibria of reactive systems. He carried out the thermodynamic analyses of biocatalytic processes in terms of phase and chemi......As part of his PhD studies, Gündüz Güzel examined the thermodynamics of reactions involved in biocatalytic biodiesel production processes, with a specific focus on phase equilibria of reactive systems. He carried out the thermodynamic analyses of biocatalytic processes in terms of phase...... and chemical equilibria as part of his main sustainable biodiesel project. The transesterification reaction of vegetable oils or fats with an aliphatic alcohol – in most cases methanol or ethanol – yields biodiesel (long-chain fatty acid alkyl esters – FAAE) as the main product in the presence of alkaline....../acid catalysts or biocatalysts (free or immobilised lipase enzymes). The reaction by-product glycerol is immiscible with the ester products (FAAE and oils/fats) in addition to the partial miscibility problem of methanol or ethanol with oils/fats. The insoluble parts of alcohol feeds or by-products form emulsion...

  8. Biocatalytic portfolio of Basidiomycota.

    Science.gov (United States)

    Schmidt-Dannert, Claudia

    2016-04-01

    Basidiomycota fungi have received little attention for applications in biocatalysis and biotechnology and remain greatly understudied despite their importance for carbon recycling, ecosystem functioning and medicinal properties. The steady influx of genome data has facilitated detailed studies aimed at understanding the evolution and function of fungal lignocellulose degradation. These studies and recent explorations into the secondary metabolomes have uncovered large portfolios of enzymes useful for biocatalysis and biosynthesis. This review will provide an overview of the biocatalytic repertoires of Basidiomycota characterized to date with the hope of motivation more research into the chemical toolkits of this diverse group of fungi. PMID:26812494

  9. Oxidase-based biocatalytic processes

    DEFF Research Database (Denmark)

    Ramesh, Hemalata; Woodley, John; Krühne, Ulrich

    Biocatalytic processes are gaining significant focus in frontiers where they offer unique advantages(selectivity and mild operating conditions) over chemical catalysts. It is therefore not surprising that therehave been many industrial biocatalytic processes implemented.Despite past successes, the...... implementation of a new biocatalytic process still presents some challenges (demands placed on the biocatalyst) in terms of the requirements to make a viable industrial process. Inorder for a biocatalytic process to be economically successful, it is necessary that certain a set of targetmetrics (product titre...... reaction species (substrate and product volatility for example) and the process (such as oxygen supply, ability to control pH) and are classified as reaction-related and process-related constraintsrespectively. Although the development of biocatalyst and process engineering tools offers a number...

  10. Biocatalytic material comprising multilayer enzyme coated fiber

    Science.gov (United States)

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    The present invention relates generally to high stability, high activity biocatalytic materials and processes for using the same. The materials comprise enzyme aggregate coatings having high biocatalytic activity and stability useful in heterogeneous environment. These new materials provide a new biocatalytic immobilized enzyme system with applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  11. Application of environmental and economic metrics to guide the development of biocatalytic processes

    DEFF Research Database (Denmark)

    Lima Ramos, Joana; Tufvesson, Pär; Woodley, John

    2014-01-01

    The increasing industrial interest in biocatalytic processes is predominantly driven by the need for selective chemistry, with high reaction yield (Y-reaction) and few side reactions, as well as the need for optically pure chiral molecules (in particularly in the pharmaceutical industry). Interes......The increasing industrial interest in biocatalytic processes is predominantly driven by the need for selective chemistry, with high reaction yield (Y-reaction) and few side reactions, as well as the need for optically pure chiral molecules (in particularly in the pharmaceutical industry...

  12. Model visualization for evaluation of biocatalytic processes

    DEFF Research Database (Denmark)

    Law, HEM; Lewis, DJ; McRobbie, I;

    2008-01-01

    Biocatalysis offers great potential as an additional, and in some cases as an alternative, synthetic tool for organic chemists, especially as a route to introduce chirality. However, the implementation of scalable biocatalytic processes nearly always requires the introduction of process and....../or biocatalyst enhancements to ensure effective scale-up. This paper describes a paradigm for the purpose of evaluating biocatalytic processes in order to provide guidance on process and biocatalyst modification. The paradigm is illustrated with the biocatalytic synthesis of S,S-ethylenediaminedisuccinic acid (S......,S-EDDS), a biodegradable chelant, and is characterised by the use of model visualization using `windows of operation"....

  13. Biocatalytic process development using microfluidic miniaturized systems

    DEFF Research Database (Denmark)

    Krühne, Ulrich; Heintz, Søren; Ringborg, Rolf Hoffmeyer;

    2014-01-01

    The increasing interest in biocatalytic processes means there is a clear need for a new systematic development paradigm which encompasses both protein engineering and process engineering. This paper argues that through the use of a new microfluidic platform, data can be collected more rapidly and...

  14. Efficient Biocatalytic Synthesis of Chiral Chemicals.

    Science.gov (United States)

    Zhang, Zhi-Jun; Pan, Jiang; Ma, Bao-Di; Xu, Jian-He

    2016-01-01

    Chiral chemicals are a group of important chiral synthons for the synthesis of a series of pharmaceuticals, agrochemicals, and fine chemicals. In past decades, a number of biocatalytic approaches have been developed for the green and effective synthesis of various chiral chemicals. However, the practical application of these biocatalytic processes is still hindered by the lack of highly efficient and robust biocatalysts, which usually results in the low volumetric productivity and high cost of the bioprocesses. Further step forward of biocatalysis in industrial application strongly requires the development of versatile and highly efficient biocatalysts, aiming to increase the process efficiency and facilitate the downstream processing. Recently, the fast growth of genome sequences in the database in post-genomic era offers great opportunities for accessing numerous biocatalysts with practical application potential, and the so-called genome mining approach provides time-effective and highly specific strategy for the fast identification of target enzymes with desired properties and outperforms the traditional screening of soil samples for microbial enzyme producers of interest. A number of biocatalytic processes with industrial application potential were developed thereafter. Further development of protein engineering strategies, process optimization, and cooperative work between biologists, organic chemists, and engineers is expected to make biocatalysis technology the first choice approach for the eco-friendly, highly efficient, and cost-effective synthesis of chiral chemicals in the near future. PMID:25537446

  15. Sustainable Biocatalytic Biodiesel Production:A Thermodynamic Analysis

    OpenAIRE

    Güzel, Günduz

    2012-01-01

    As part of his PhD studies, Gündüz Güzel examined the thermodynamics of reactions involved in biocatalytic biodiesel production processes, with a specific focus on phase equilibria of reactive systems. He carried out the thermodynamic analyses of biocatalytic processes in terms of phase and chemical equilibria as part of his main sustainable biodiesel project. The transesterification reaction of vegetable oils or fats with an aliphatic alcohol – in most cases methanol or ethanol – yields biod...

  16. A methodology for development of biocatalytic processes

    DEFF Research Database (Denmark)

    Lima Ramos, Joana

    , is also the source of the greatest opportunities. Indeed, recombinant DNA technology offers a superb complement to process technologies. Potentially this is one of the biggest advantages of biocatalysis when compared with conventional chemical catalysis, where all the reaction boundaries are fixed...... and their relationship with the overall process is not clear.The work described in this thesis presents a methodological approach for early stage development of biocatalytic processes, understanding and dealing with the reaction, biocatalyst and process constraints. When applied, this methodology has a decisive role...... tools, the number of options can be much reduced and the current process bottlenecks identified. By applying a priori this methodology, the Laboratory experts are better able to understand the most favourable operating conditions at fullscale and thus be able to collect information at these relevant...

  17. Biocatalytic Self-Cleaning Polymer Membranes

    Directory of Open Access Journals (Sweden)

    Agnes Schulze

    2015-09-01

    Full Text Available Polymer membrane surfaces have been equipped with the digestive enzyme trypsin. Enzyme immobilization was performed by electron beam irradiation in aqueous media within a one-step method. Using this method, trypsin was covalently and side-unspecific attached to the membrane surface. Thus, the use of preceding polymer functionalization and the use of toxic solvents or reagents can be avoided. The resulting membranes showed significantly improved antifouling properties as demonstrated by repeated filtration of protein solutions. Furthermore, the biocatalytic membrane can be simply “switched on” to actively degrade a fouling layer on the membrane surface and regain the initial permeability. The membrane pore structure (pore size and porosity was neither damaged by the electron beam treatment nor blocked by the enzyme loading, ensuring a stable membrane performance.

  18. Biocatalytic Pathway Selection in Transient Tripeptide Nanostructures.

    Science.gov (United States)

    Pappas, Charalampos G; Sasselli, Ivan R; Ulijn, Rein V

    2015-07-01

    Structural adaption in living systems is achieved by competing catalytic pathways that drive assembly and disassembly of molecular components under the influence of chemical fuels. We report on a simple mimic of such a system that displays transient, sequence-dependent formation of supramolecular nanostructures based on biocatalytic formation and hydrolysis of self-assembling tripeptides. The systems are catalyzed by α-chymotrypsin and driven by hydrolysis of dipeptide aspartyl-phenylalanine-methyl ester (the sweetener aspartame, DF-OMe). We observed switch-like pathway selection, with the kinetics and consequent lifetime of transient nanostructures controlled by the peptide sequence. In direct competition, kinetic (rather than thermodynamic) component selection is observed. PMID:26014441

  19. Biocatalytic desulfurization of petroleum and middle distillates

    International Nuclear Information System (INIS)

    Biocatalytic Desulfurization (BDS) represents an alternative approach to the reduction of sulfur in fossil fuels. The objective is to use bacteria to selectively remove sulfur from petroleum and middle distillate fractions, without the concomitant release of carbon. Recently, bacteria have been developed which have the ability to desulfurize dibenzothiophene (DBT) and other organosulfur molecules. These bacteria are being developed for use in a biocatalyst-based desulfurization process. Analysis of preliminary conceptual engineering designs has shown that this process has the potential to complement conventional technology as a method to temper the sulfur levels in crude oil, or remove the recalcitrant sulfur in middle distillates to achieve the deep desulfurization mandated by State and Federal regulations. This paper describes the results of initial feasibility studies, sensitivity analyses and conceptual design work. Feasibility studies with various crude oils and middle distillates achieved unoptimized desulfurization levels of 40-80%. Sensitivity analyses indicate that total desulfurization costs of about $3.00 per barrel for crude oil and less than $2.00 per barrel for diesel are possible. Key criteria for commercial success of the process include the cost and half-life of the biocatalyst, residence time in the reactor, oil/water ratios required to extract the sulfur and the disposition of the separated sulfur products. 9 refs., 3 figs

  20. Sustainable biocatalytic biodiesel production : A thermodynamic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Guezel, G.

    2012-09-15

    In the present thesis it was aimed at achieving thermodynamic analysis of reactions involved in enzymatic biodiesel production with specific focus on chemical and phase equilibria of reactive systems. Lipase-catalyzed biodiesel production (biocatalytic ethanolysis) presents significant advantages: Easy recovery of glycerol, no complex down-processing operations for elimination of catalyst and salt, and requires less organic solvent and lower energy consumption compared with conventional chemical methods. In overall, the major aims of this thesis were evaluating and subsequently finding feasible solutions to the questions emerged during the corresponding studies that have been performed worldwide. Some of the questions that were answered as appropriate as possible can be listed as follows: 1) What is the solubility of EtOH in vegetable oils and in FAEE blends and how does it change with temperature? 2) Is it possible to prevent denaturing impact of EtOH on biocatalysts? 3) What are the feedstock content (water and FFA) impacts on glycerol and EtOH miscibility with ester species? 4) Is it necessary removing glycerol by-product simultaneously? 5) Is it feasible providing monophasic or homogeneous reaction media that procure lower external mass transfer resistance? 6) What are the moisture absorption limits of FAAE species? 7) How are the interactions of reactive species in terms of miscibility/immiscibility phenomena? 8) Is it thermodynamically feasible providing monophasic reaction media? 9) How can LLE and VLE phase behaviors help to determine optimum reaction conditions? 10) How can the results of LLE and VLE studies be used so as to determine appropriate refining operations? (LN)

  1. Biocatalytic Separation of N-7/N-9 Guanine Nucleosides

    DEFF Research Database (Denmark)

    Singh, Sunil K; Sharma, Vivek K; Olsen, Carl Erik;

    2010-01-01

    Vorbrüggen coupling of trimethylsilylated 2-N-isobutanoylguanine with peracetylated pentofuranose derivatives generally gives inseparable N-7/N-9 glycosyl mixtures. We have shown that the two isomers can be separated biocatalytically by Novozyme-435-mediated selective deacetylation of the 5'-O...

  2. Chemistry

    International Nuclear Information System (INIS)

    The chemical research and development efforts related to the design and ultimate operation of molten-salt breeder reactor systems are concentrated on fuel- and coolant-salt chemistry, including the development of analytical methods for use in these systems. The chemistry of tellurium in fuel salt is being studied to help elucidate the role of this element in the intergranular cracking of Hastelloy N. Studies were continued of the effect of oxygen-containing species on the equilibrium between dissolved UF3 and dissolved UF4, and, in some cases, between the dissolved uranium fluorides and graphite, and the UC2. Several aspects of coolant-salt chemistry are under investigation. Hydroxy and oxy compounds that could be formed in molten NaBF4 are being synthesized and characterized. Studies of the chemistry of chromium (III) compounds in fluoroborate melts were continued as part of a systematic investigation of the corrosion of structural alloys by coolant salt. An in-line voltammetric method for determining U4+/U3+ ratios in fuel salt was tested in a forced-convection loop over a six-month period. (LK)

  3. Biocatalytic membranes for ultrafiltration treatment of wastewater containing dyes

    Energy Technology Data Exchange (ETDEWEB)

    Konovalova, V.V.; Bryk, M.T.; Nigmatullin, R.R.; Gvozdyak, P.I.; Udilova, O.F. [Dept. of Chemistry, Univ. of ' ' Kyiv-Mohyla Academy' ' , Kyiv (Ukraine)

    2000-12-01

    A possibility to prepare the biofunctional membranes showing the biocatalytic properties and use those in post-treatment of wastewater containing synthetic dyes have been established. Selected Pseudomonas mendocina and Bacillus subtilis cultures were used as biocatalysts for dye destruction. It has been established that cells in spore form are able to survive in N-methylpyrrolidone that allow to use method of polymer solution casting for membrane preparation. The optimal conditions for entrapping of whole cells of microorganisms into the polymer matrix have been determined. Membrane biocatalytic activity has been studied depending on method of casting solution preparation, biocatalyst loading and operating parameters. Dye destruction occurs both in membrane pores and on membrane surface. Membrane obtained provide discolouring of treated solutions (permeate). The dye concentration in retentate depends on the trans-membrane fluxes. The concentration in retentate need not be observed at relatively low fluxes (up to 20 l/m{sup 2} h). (orig.)

  4. Biocatalytic synthesis of highly ordered degradable dextran-based hydrogels

    OpenAIRE

    Ferreira, Lino; Gil, Maria H.; Cabrita, António M. S.; Dordick, Jonathan S.

    2005-01-01

    We have prepared unique macroporous and ordered dextran-based hydrogels using a single-step biocatalytic transesterification reaction between dextran and divinyladipate in neat dimethylsulfoxide. These hydrogels show a unimodal distribution of interconnected pores with average diameters from 0.4 to 2.0 [mu]m depending on the degree of substitution. In addition, the hydrogels show a higher elastic modulus for a given swelling ratio than chemically synthesized dextran-based hydrogels. In vivo s...

  5. Chemistry

    International Nuclear Information System (INIS)

    Research progress is reported in programs on fuel-salt chemistry, properties of compounds in the Li--Te system, Te spectroscopy UF4--H equilibria, porous electrode studies of molten salts, fuel salt-coolant salt reactions, thermodynamic properties of transition-metal fluorides, and properties of sodium fluoroborate. Developmental work on analytical methods is summarized including in-line analysis of molten MSBR fuel, analysis of coolant-salts for tritium, analysis of molten LiF--BeF2--ThF4 for Fe and analysis of LiF--BeF--ThF4 for Te

  6. Chemistry

    International Nuclear Information System (INIS)

    Research and development activities dealing with the chemical problems related to design and ultimate operation of molten-salt reactor systems are described. An experimental test stand was constructed to expose metallurgical test specimens to Te2 vapor at defined temperatures and deposition rates. To better define the chemistry of fluoroborate coolant, several aspects are being investigated. The behavior of hydroxy and oxy compounds in molten NaBF4 is being investigated to define reactions and compounds that may be involved in corrosion and/or could be involved in methods for trapping tritium. Two corrosion products of Hastelloy N, Na3CrF6 and Na5Cr3F14, were identified from fluoroborate systems. The evaluation of fluoroborate and alternate coolants continued. Research on the behavior of hydrogen and its isotopes is summarized. The solubilities of hydrogen, deuterium, and helium in Li2BeF4 are very low. The sorption of tritium on graphite was found to be significant (a few milligrams of tritium per kilogram of graphite), possibly providing a means of sequestering a portion of the tritium produced. Development of analytical methods continued with emphasis on voltammetric and spectrophotometric techniques for the in-line analysis of corrosion products such as Fe2+ and Cr3+ and the determination of the U3+/U4+ ratio in MSBR fuel salt. Similar studies were conducted with the NaBF4--NaF coolant salt. Information developed during the previous operation of the CSTF has been assessed and used to formulate plans for evaluation of in-line analytical methods in future CSTF operations. Electroanalytical and spectrophotometric research suggests that an electroactive protonic species is present in molten NaBF4--NaF, and that this species rapidly equilibrates with a volatile proton-containing species. Data obtained from the CSTF indicated that tritium was concentrated in the volatile species. (JGB)

  7. Enzyme-polymer composites with high biocatalytic activity and stability

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jungbae; Kosto, Timothy J.; Manimala, Joseph C.; Nauman, E B.; Dordick, Jonathan S.

    2004-08-22

    We have applied vacuum-spraying and electrospinning to incorporate an enzyme into a polymer matrix, creating a novel and highly active biocatalytic composite. As a unique technical approach, enzymes were co-dissolved in toluene with polymers, and the solvent was then rapidly removed by injecting the mixture into a vacuum chamber or by electrospinning. Subsequent crosslinking of the enzyme with glutaraldehyde resulted in stable entrapped enzyme within the polymeric matrices. For example, an amorphous composite of alpha-chymotrypsin and polyethylene showed no significant loss of enzymatic activity in aqueous buffer for one month. Nanofibers of alpha-chymotrypsin and polystyrene also showed no decrease in activity for more than two weeks. The normalized activity of amorphous composite in organic solvents was 3-13 times higher than that of native alpha-chymotrypsin. The activity of nanofibers was 5-7 times higher than that of amorphous composite in aqueous buffer solution. The composites of alpha-chymotrypsin and polymers demonstrate the feasibility of obtaining a wide variety of active and stable biocatalytic materials with many combinations of enzymes and polymers.

  8. Multi-step biocatalytic strategies for chiral amino alcohol synthesis.

    Science.gov (United States)

    Villegas-Torres, Maria F; Martinez-Torres, R Julio; Cázares-Körner, Armando; Hailes, Helen; Baganz, Frank; Ward, John

    2015-12-01

    Chiral amino alcohols are structural motifs present in sphingolipids, antibiotics, and antiviral glycosidase inhibitors. Their chemical synthesis presents several challenges in establishing at least two chiral centres. Here a de novo metabolic pathway using a transketolase enzyme coupled with a transaminase enzyme has been assembled. To synthesise this motif one of the strategies to obtain high conversions from the transaminase/transketolase cascade is the use of hydroxypyruvate (HPA) as a two-carbon donor for the transketolase reaction; although commercially available it is relatively expensive limiting application of the pathway on an industrial scale. Alternately, HPA can be synthesised but this introduces a further synthetic step. In this study two different biocatalytic strategies were developed for the synthesis of (2S,3R)-2-amino-1,3,4-butanetriol (ABT) without adding HPA into the reaction. Firstly, a sequential cascade of three enzymatic steps (two transaminases and one transketolase) for the synthesis of ABT from serine, pyruvate and glycolaldehyde as substrates. Secondly, a two-step recycling cascade where serine is used as donor to aminate erythrulose (catalysed by a transketolase) for the simultaneous synthesis of ABT and HPA. In order to test the novel pathways, three new transaminases are described, two ω-transaminases able to accept a broad range of amine acceptors with serine as amine donor; and an α-transaminase, which showed high affinity towards serine (KM: 18mM) using pyruvate as amine acceptor. After implementation of the above enzymes in the biocatalytic pathways proposed in this paper, the two-step recycling pathway was found to be the most promising for its integration with E. coli metabolism. It was more efficient (10-fold higher conversion), more sustainable and cost-effective (use of low cost natural substrates and only two enzymes), and the reaction could be performed in a one-pot system. PMID:26453469

  9. Transition metal bioconjugates with an organometallic link between the metal and the biomolecular scaffold

    OpenAIRE

    Monney, Angèle; Albrecht, Martin

    2013-01-01

    This overview compiles recent advances in the synthesis and application of organometallic bioconjugates that comprise a metal–carbon linkage between the metal and the biomolecular scaffold. This specific area of bioorganometallic chemistry has been spurred by the discovery of naturally occurring bioorganometallic compounds and afforded organometallic bioconjugates from transition metals binding to amino acids, nucleic acids and other biomolecules. These artificial bioorganometallic compounds ...

  10. A Study and Application of Biocatalytic Synthesis of (S-N-Boc-3-hydroxypiperidine

    Directory of Open Access Journals (Sweden)

    Chen Ying

    2015-01-01

    Full Text Available This paper first uses the environmental friendly whole cell of biocatalyst pichia pastoris SIT2014 to asymmetrically synthesized anti-tumor drug of chiral intermediate (S-N-Boc-3-hydroxypiperidine.. Improve the final biocatalytic reduction yield to 85.4% based on the study of fermentation optimization and biocatalytic asymmetrical reduction system for pichia pastoris. The ee value of obtained reduction product (S-N-Boc-3-hydroxypiperidine hits over 99%. The study of this article is a successful case where the biocatalyst is applied to the green synthesis of chiral intermediate of anti-tumor drug.

  11. Rational Improvement of Simvastatin Synthase Solubility in Escherichia coli Leads to Higher Whole-cell Biocatalytic Activity

    OpenAIRE

    Xie, Xinkai; Pashkov, Inna; Gao, Xue; Guerrero, Jennifer L.; Yeates, Todd O; Tang, Yi

    2009-01-01

    Simvastatin is the active pharmaceutical ingredient of the blockbuster cholesterol lowering drug Zocor. We have previously developed an Escherichia coli based whole-cell biocatalytic platform towards the synthesis of simvastatin sodium salt (SS) starting from the precursor monacolin J sodium salt (MJSS). The centerpiece of the biocatalytic approach is the simvastatin synthase LovD, which is highly prone to misfolding and aggregation when overexpressed from E. coli. Increasing the solubility o...

  12. Uniform lab-scale biocatalytic nanoporous latex coatings for reactive microorganisms.

    Science.gov (United States)

    Gosse, Jimmy L; Flickinger, Michael C

    2011-01-01

    This chapter describes a method for generating uniform lab-scale biocatalytic nanoporous latex coatings. Nearly everything we come into contact with on a daily basis has been coated with some polymer material. High-speed waterborne polymer coating and ink-jet printing techniques are mature technologies. Methods for immobilizing microorganisms in lab-scale waterborne latex biocatalytic coatings draw on existing coating technologies for generating precision industrial paint and paper coatings and would therefore be amenable to scale up in future applications. An inherent problem for many lab-scale techniques is coating uniformity. The method described here has been developed to dramatically increase the uniformity of multiple individual small surface area coatings derived from a single coating template by minimizing edge effects due to emulsion drying adjacent to the edge of the mask. PMID:21553194

  13. Biocatalytic Synthesis of Chiral Alcohols and Amino Acids for Development of Pharmaceuticals

    OpenAIRE

    Patel, Ramesh N.

    2013-01-01

    Chirality is a key factor in the safety and efficacy of many drug products and thus the production of single enantiomers of drug intermediates and drugs has become increasingly important in the pharmaceutical industry. There has been an increasing awareness of the enormous potential of microorganisms and enzymes derived there from for the transformation of synthetic chemicals with high chemo-, regio- and enatioselectivities. In this article, biocatalytic processes are described for the synthe...

  14. Biocatalytic synthesis of acrylates in supercritical fluids: tuning enzyme activity by changing pressure.

    OpenAIRE

    Kamat, S.V.; Iwaskewycz, B; Beckman, E J; Russell, A.J.

    1993-01-01

    Supercritical fluids are a unique class of nonaqueous media in which biocatalytic reactions can occur. The physical properties of supercritical fluids, which include gas-like diffusivities and liquid-like densities, can be predictably controlled with changing pressure. This paper describes how adjustment of pressure, with the subsequent predictable changes of the dielectric constant and Hildebrand solubility parameter for fluoroform, ethane, sulfur hexafluoride, and propane, can be used to ma...

  15. Actinobase: Database on molecular diversity, phylogeny and biocatalytic potential of salt tolerant alkaliphilic actinomycetes

    OpenAIRE

    Sharma, Amit K; Gohel, Sangeeta; Singh, Satya P.

    2012-01-01

    Actinobase is a relational database of molecular diversity, phylogeny and biocatalytic potential of haloalkaliphilic actinomycetes. The main objective of this data base is to provide easy access to range of information, data storage, comparison and analysis apart from reduced data redundancy, data entry, storage, retrieval costs and improve data security. Information related to habitat, cell morphology, Gram reaction, biochemical characterization and molecular features would allow researchers...

  16. Biocatalytic anode for glucose oxidation utilizing carbon nanotubes for direct electron transfer with glucose oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Vaze, Abhay; Hussain, Nighat; Tang, Chi [Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060 (United States); Leech, Donal [School of Chemistry, National University of Ireland, Galway (Ireland); Rusling, James [Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060 (United States); Department of Cell Biology, University of Connecticut Health Center, Farmington, CT 06032 (United States); School of Chemistry, National University of Ireland, Galway (Ireland)

    2009-10-15

    Covalently linked layers of glucose oxidase, single-wall carbon nanotubes and poly-L-lysine on pyrolytic graphite resulted in a stable biofuel cell anode featuring direct electron transfer from the enzyme. Catalytic response observed upon addition of glucose was due to electrochemical oxidation of FADH{sub 2} under aerobic conditions. The electrode potential depended on glucose concentration. This system has essential attributes of an anode in a mediator-free biocatalytic fuel cell. (author)

  17. Application of Enzyme Coupling Reactions to Shift Thermodynamically Limited Biocatalytic Reactions

    DEFF Research Database (Denmark)

    Abu, Rohana; Woodley, John M.

    2015-01-01

    , it can be challenging to combine several engineered enzymes in vitro for the conversion of non-natural substrates. In this mini-review we focus on enzyme coupling reactions as a tool to alleviate thermodynamic constraints in synthetically useful biocatalytic reactions. The implications of...... shift the equilibrium of otherwise thermodynamically unfavourable reactions to give a higher conversion of the target product. By coupling an energetically unfavourable reaction with a more favourable one, the multi-enzyme cascade mimics the approach taken in nature in metabolic pathways. Nevertheless...

  18. Trehalose Analogues: Latest Insights in Properties and Biocatalytic Production

    Directory of Open Access Journals (Sweden)

    Maarten Walmagh

    2015-06-01

    Full Text Available Trehalose (α-d-glucopyranosyl α-d-glucopyranoside is a non-reducing sugar with unique stabilizing properties due to its symmetrical, low energy structure consisting of two 1,1-anomerically bound glucose moieties. Many applications of this beneficial sugar have been reported in the novel food (nutricals, medical, pharmaceutical and cosmetic industries. Trehalose analogues, like lactotrehalose (α-d-glucopyranosyl α-d-galactopyranoside or galactotrehalose (α-d-galactopyranosyl α-d-galactopyranoside, offer similar benefits as trehalose, but show additional features such as prebiotic or low-calorie sweetener due to their resistance against hydrolysis during digestion. Unfortunately, large-scale chemical production processes for trehalose analogues are not readily available at the moment due to the lack of efficient synthesis methods. Most of the procedures reported in literature suffer from low yields, elevated costs and are far from environmentally friendly. “Greener” alternatives found in the biocatalysis field, including galactosidases, trehalose phosphorylases and TreT-type trehalose synthases are suggested as primary candidates for trehalose analogue production instead. Significant progress has been made in the last decade to turn these into highly efficient biocatalysts and to broaden the variety of useful donor and acceptor sugars. In this review, we aim to provide an overview of the latest insights and future perspectives in trehalose analogue chemistry, applications and production pathways with emphasis on biocatalysis.

  19. Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Tamayo-Ramos Juan Antonio

    2012-12-01

    Full Text Available Abstract Background Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. Results The laccase-like multicopper oxidases McoA, McoB and McoG from the commonly used cell factory Aspergillus niger were homologously expressed, purified and analyzed for their biocatalytic potential. All three recombinant enzymes were monomers with apparent molecular masses ranging from 80 to 110 kDa. McoA and McoG resulted to be blue, whereas McoB was yellow. The newly obtained oxidases displayed strongly different activities towards aromatic compounds and synthetic dyes. McoB exhibited high catalytic efficiency with N,N-dimethyl-p-phenylenediamine (DMPPDA and 2,2-azino-di(3-ethylbenzthiazoline sulfonic acid (ABTS, and appeared to be a promising biocatalyst. Besides oxidizing a variety of phenolic compounds, McoB catalyzed successfully the decolorization and detoxification of the widely used textile dye malachite green. Conclusions The A. niger McoA, McoB, and McoG enzymes showed clearly different catalytic properties. Yellow McoB showed broad substrate specificity, catalyzing the oxidation of several phenolic compounds commonly present in different industrial effluents. It also harbored high decolorization and detoxification activity with the synthetic dye malachite green, showing to have an interesting potential as a new industrial biocatalyst.

  20. Recent advances on halohydrin dehalogenases-from enzyme identification to novel biocatalytic applications.

    Science.gov (United States)

    Schallmey, Anett; Schallmey, Marcus

    2016-09-01

    Halohydrin dehalogenases are industrially relevant enzymes that catalyze the reversible dehalogenation of vicinal haloalcohols with formation of the corresponding epoxides. In the reverse reaction, also other negatively charged nucleophiles such as azide, cyanide, or nitrite are accepted besides halides to open the epoxide ring. Thus, novel C-N, C-C, or C-O bonds can be formed by halohydrin dehalogenases, which makes them attractive biocatalysts for the production of various β-substituted alcohols. Despite the fact that only five individual halohydrin dehalogenase enzyme sequences have been known until recently enabling their heterologous production, a large number of different biocatalytic applications have been reported using these enzymes. The recent characterization of specific sequence motifs has facilitated the identification of novel halohydrin dehalogenase sequences available in public databases and has largely increased the number of recombinantly available enzymes. These will help to extend the biocatalytic repertoire of this enzyme family and to foster novel biotechnological applications and developments in the future. This review gives a general overview on the halohydrin dehalogenase enzyme family and their biochemical properties and further focuses on recent developments in halohydrin dehalogenase biocatalysis and protein engineering. PMID:27502414

  1. A process optimization for bio-catalytic production of substituted catechols (3-nitrocatechol and 3-methylcatechol

    Directory of Open Access Journals (Sweden)

    Tiwary Bhupendra N

    2010-06-01

    Full Text Available Abstract Background Substituted catechols are important precursors for large-scale synthesis of pharmaceuticals and other industrial products. Most of the reported chemical synthesis methods are expensive and insufficient at industrial level. However, biological processes for production of substituted catechols could be highly selective and suitable for industrial purposes. Results We have optimized a process for bio-catalytic production of 3-substituted catechols viz. 3-nitrocatechol (3-NC and 3-methylcatechol (3-MC at pilot scale. Amongst the screened strains, two strains viz. Pseudomonas putida strain (F1 and recombinant Escherichia coli expression clone (pDTG602 harboring first two genes of toluene degradation pathway were found to accumulate 3-NC and 3-MC respectively. Various parameters such as amount of nutrients, pH, temperature, substrate concentration, aeration, inoculums size, culture volume, toxicity of substrate and product, down stream extraction, single step and two-step biotransformation were optimized at laboratory scale to obtain high yields of 3-substituted catechols. Subsequently, pilot scale studies were performed in 2.5 liter bioreactor. The rate of product accumulation at pilot scale significantly increased up to ~90-95% with time and high yields of 3-NC (10 mM and 3-MC (12 mM were obtained. Conclusion The biocatalytic production of 3-substituted catechols viz. 3-NC and 3-MC depend on some crucial parameters to obtain maximum yields of the product at pilot scale. The process optimized for production of 3-substituted catechols by using the organisms P. putida (F1 and recombinant E. coli expression clone (pDTG602 may be useful for industrial application.

  2. Enzyme immobilization by fouling in ultrafiltration membranes: Impact of membrane configuration and type on flux behavior and biocatalytic conversion efficacy

    DEFF Research Database (Denmark)

    Luo, Jianquan; Meyer, Anne S.; Jonsson, Gunnar Eigil;

    2014-01-01

    and PLGC regenerated cellulose membranes. With these two highly hydrophilic membranes, the ADH enzyme activity was fully retained even after 24h of storage of the membrane. Filtration blocking and resistance models were used to analyze the fouling/immobilization mechanisms and give explanations......Enzyme-immobilization in membranes accomplished by fostering membrane fouling was evaluated. Four different membrane configurations and five membranes were compared for immobilization of alcohol dehydrogenase (ADH) in terms of enzyme loading, permeate flux and final biocatalytic conversion....... The membrane configuration impacted the efficiency of the enzyme-immobilization as well as the biocatalytic-membrane reaction, and the “sandwich mode”, with an extra polypropylene support above the membrane skin layer, worked best due to its high flux and stable conversion. Among the membranes, a GR51PP...

  3. Cellulose Digestion and Metabolism Induced Biocatalytic Transitions in Anaerobic Microbial Ecosystems

    Directory of Open Access Journals (Sweden)

    Akira Yamazawa

    2013-12-01

    Full Text Available Anaerobic digestion of highly polymerized biomass by microbial communities present in diverse microbial ecosystems is an indispensable metabolic process for biogeochemical cycling in nature and for industrial activities required to maintain a sustainable society. Therefore, the evaluation of the complicated microbial metabolomics presents a significant challenge. We here describe a comprehensive strategy for characterizing the degradation of highly crystallized bacterial cellulose (BC that is accompanied by metabolite production for identifying the responsible biocatalysts, including microorganisms and their metabolic functions. To this end, we employed two-dimensional solid- and one-dimensional solution-state nuclear magnetic resonance (NMR profiling combined with a metagenomic approach using stable isotope labeling. The key components of biocatalytic reactions determined using a metagenomic approach were correlated with cellulose degradation and metabolic products. The results indicate that BC degradation was mediated by cellulases that contain carbohydrate-binding modules and that belong to structural type A. The degradation reactions induced the metabolic dynamics of the microbial community and produced organic compounds, such as acetic acid and propionic acid, mainly metabolized by clostridial species. This combinatorial, functional and structural metagenomic approach is useful for the comprehensive characterization of biomass degradation, metabolic dynamics and their key components in diverse ecosystems.

  4. Expedient synthesis of C-aryl carbohydrates by consecutive biocatalytic benzoin and aldol reactions.

    Science.gov (United States)

    Hernández, Karel; Parella, Teodor; Joglar, Jesús; Bujons, Jordi; Pohl, Martina; Clapés, Pere

    2015-02-16

    The introduction of aromatic residues connected by a C-C bond into the non-reducing end of carbohydrates is highly significant for the development of innovative structures with improved binding affinity and selectivity (e.g., C-aril-sLex). In this work, an expedient asymmetric "de novo" synthetic route to new aryl carbohydrate derivatives based on two sequential stereoselectively biocatalytic carboligation reactions is presented. First, the benzoin reaction of aromatic aldehydes to dimethoxyacetaldehyde is conducted, catalyzed by benzaldehyde lyase from Pseudomonas fluorescens biovar I. Then, the α-hydroxyketones formed are reduced by using NaBH4 yielding the anti diol. After acetal hydrolysis, the aldol addition of dihydroxyacetone, hydroxyacetone, or glycolaldehyde catalyzed by the stereocomplementary D-fructose-6-phosphate aldolase and L-rhamnulose-1-phosphate aldolase is performed. Both aldolases accept unphosphorylated donor substrates, avoiding the need of handling the phosphate group that the dihydroxyacetone phosphate-dependent aldolases require. In this way, 6-C-aryl-L-sorbose, 6-C-aryl-L-fructose, 6-C-aryl-L-tagatose, and 5-C-aryl-L-xylose derivatives are prepared by using this methodology. PMID:25640727

  5. Microbiome and Biocatalytic Bacteria in Monkey Cup (Nepenthes Pitcher) Digestive Fluid.

    Science.gov (United States)

    Chan, Xin-Yue; Hong, Kar-Wai; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Tropical carnivorous plant, Nepenthes, locally known as "monkey cup", utilises its pitcher as a passive trap to capture insects. It then secretes enzymes into the pitcher fluid to digest the insects for nutrients acquisition. However, little is known about the microbiota and their activity in its pitcher fluid. Eighteen bacteria phyla were detected from the metagenome study in the Nepenthes pitcher fluid. Proteobacteria, Bacteroidetes and Actinobacteria are the dominant phyla in the Nepenthes pitcher fluid. We also performed culturomics approach by isolating 18 bacteria from the Nepenthes pitcher fluid. Most of the bacterial isolates possess chitinolytic, proteolytic, amylolytic, and cellulolytic and xylanolytic activities. Fifteen putative chitinase genes were identified from the whole genome analysis on the genomes of the 18 bacteria isolated from Nepenthes pitcher fluid and expressed for chitinase assay. Of these, six clones possessed chitinase activity. In conclusion, our metagenome result shows that the Nepenthes pitcher fluid contains vast bacterial diversity and the culturomic studies confirmed the presence of biocatalytic bacteria within the Nepenthes pitcher juice which may act in symbiosis for the turn over of insects trapped in the Nepenthes pitcher fluid. PMID:26817720

  6. Two-Input Enzymatic Logic Gates Made Sigmoid by Modifications of the Biocatalytic Reaction Cascades

    CERN Document Server

    Zavalov, Oleksandr; Halamek, Jan; Halamkova, Lenka; Korkmaz, Sevim; Arugula, Mary A; Chinnapareddy, Soujanya; Katz, Evgeny; Privman, Vladimir

    2013-01-01

    Computing based on biochemical processes is a newest rapidly developing field of unconventional information and signal processing. In this paper we present results of our research in the field of biochemical computing and summarize the obtained numerical and experimental data for implementations of the standard two-input OR and AND gates with double-sigmoid shape of the output signal. This form of response was obtained as a function of the two inputs in each of the realized biochemical systems. The enzymatic gate processes in the first system were activated with two chemical inputs and resulted in optically detected chromogen oxidation, which happens when either one or both of the inputs are present. In this case, the biochemical system is functioning as the OR gate. We demonstrate that the addition of a "filtering" biocatalytic process leads to a considerable reduction of the noise transmission factor and the resulting gate response has sigmoid shape in both inputs. The second system was developed for functi...

  7. Silver Iodide-Chitosan Nanotag Induced Biocatalytic Precipitation for Self-Enhanced Ultrasensitive Photocathodic Immunosensor.

    Science.gov (United States)

    Gong, Lingshan; Dai, Hong; Zhang, Shupei; Lin, Yanyu

    2016-06-01

    In this work, we first exposed that the application of p-type semiconductor, silver iodide-chitosan nanoparticle (SICNP), acted as peroxidase mimetic to catalyze the bioprecipitation reaction for signal-amplification photocathodic immunosensing of human interleukin-6 (IL-6). After immobilization of captured antibody onto a polyethylenimine-functionalized carbon nitride (CN) matrix, SICNPs as photoactive tags and peroxidase mimetics were labeled on secondary antibodies, which were subsequently introduced onto the sensing interface to construct sandwich immunoassay platform through antigen-antibody specific recognition. Due to the matched energy levels between CN and AgI, the photocurrent intensity and photostability of SICNP were dramatically improved with rapid separation and transportation of photogenerated carriers. Moreover, the insoluble product in effective biocatalytic precipitation reaction served as electron acceptor to scavenge the photoexcited electron, leading to great amplification of the photocurrent signal of SICNP again. With the help of multiamplification processes, this photocathodic immunosensor presented a turn-on photoelectrochemical performance for IL-6, which showed wide linear dynamic range from 10(-6) to 10 pg/mL with the ultralow detection limit of 0.737 ag/mL. This work also performed the promising application of SICNP in developing an ultrasensitive, cost-effective, and enzyme-free photocathodic immunosensor for biomarkers. PMID:27180822

  8. Discovery and molecular and biocatalytic properties of hydroxynitrile lyase from an invasive millipede, Chamberlinius hualienensis.

    Science.gov (United States)

    Dadashipour, Mohammad; Ishida, Yuko; Yamamoto, Kazunori; Asano, Yasuhisa

    2015-08-25

    Hydroxynitrile lyase (HNL) catalyzes the degradation of cyanohydrins and causes the release of hydrogen cyanide (cyanogenesis). HNL can enantioselectively produce cyanohydrins, which are valuable building blocks for the synthesis of fine chemicals and pharmaceuticals, and is used as an important biocatalyst in industrial biotechnology. Currently, HNLs are isolated from plants and bacteria. Because industrial biotechnology requires more efficient and stable enzymes for sustainable development, we must continuously explore other potential enzyme sources for the desired HNLs. Despite the abundance of cyanogenic millipedes in the world, there has been no precise study of the HNLs from these arthropods. Here we report the isolation of HNL from the cyanide-emitting invasive millipede Chamberlinius hualienensis, along with its molecular properties and application in biocatalysis. The purified enzyme displays a very high specific activity in the synthesis of mandelonitrile. It is a glycosylated homodimer protein and shows no apparent sequence identity or homology with proteins in the known databases. It shows biocatalytic activity for the condensation of various aromatic aldehydes with potassium cyanide to produce cyanohydrins and has high stability over a wide range of temperatures and pH values. It catalyzes the synthesis of (R)-mandelonitrile from benzaldehyde with a 99% enantiomeric excess, without using any organic solvents. Arthropod fauna comprise 80% of terrestrial animals. We propose that these animals can be valuable resources for exploring not only HNLs but also diverse, efficient, and stable biocatalysts in industrial biotechnology. PMID:26261304

  9. Bad chemistry

    OpenAIRE

    Petsko, Gregory A

    2004-01-01

    General chemistry courses haven't changed significantly in forty years. Because most basic chemistry students are premedical students, medical schools have enormous influence and could help us start all over again to create undergraduate chemistry education that works.

  10. A novel system combining biocatalytic dephosphorylation of L-ascorbic acid 2-phosphate and electrochemical oxidation of resulting ascorbic acid.

    Science.gov (United States)

    Kuwahara, Takashi; Homma, Toshimasa; Kondo, Mizuki; Shimomura, Masato

    2011-03-15

    An enzyme electrode was prepared with acid phosphatase (ACP) for development of a new electric power generation system using ascorbic acid 2-phosphate (AA2P) as a fuel. The properties of the electrode were investigated with respect to biocatalytic dephosphorylation of AA2P and electrochemical oxidation of resulting ascorbic acid (AA). The enzyme electrode was fabricated by immobilization of ACP through amide linkage onto a self-assembled monolayer of 3-mercaptopropionic acid on a gold electrode. AA2P was not oxidized on a bare gold electrode in the potential sweep range from -0.1 to +0.5 V vs. Ag/AgCl. However, the enzyme electrode gave an oxidation current in citric buffer solution of pH 5 containing 10 mM of AA2P. The oxidation current began to increase at +0.2V, and reached to 5.0 μA cm(-2) at +0.5 V. The potential +0.2 V corresponded to the onset of oxidation of ascorbic acid (AA). These results suggest that the oxidation current observed with the enzyme electrode is due to AA resulting from dephosphorylation of AA2P. The oxidation current increased with increasing concentration of AA2P and almost leveled off at around the concentration of 5mM. Thus the enzyme electrode brought about biocatalytic conversion of AA2P to AA, followed by electrochemical oxidation of the AA. The oxidation current is likely to be controlled by the biocatalytic reaction. PMID:21247749

  11. Complex chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-15

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  12. Complex chemistry

    International Nuclear Information System (INIS)

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  13. Mathematical Chemistry

    OpenAIRE

    Trinajstić, Nenad; Gutman, Ivan

    2002-01-01

    A brief description is given of the historical development of mathematics and chemistry. A path leading to the meeting of these two sciences is described. An attempt is made to define mathematical chemistry, and journals containing the term mathematical chemistry in their titles are noted. In conclusion, the statement is made that although chemistry is an experimental science aimed at preparing new compounds and materials, mathematics is very useful in chemistry, among other things, to produc...

  14. Peroxidase-active cell free extract from onion solid wastes: biocatalytic properties and putative pathway of ferulic acid oxidation.

    Science.gov (United States)

    El Agha, Ayman; Makris, Dimitris P; Kefalas, Panagiotis

    2008-09-01

    The exploitation of food residuals can be a major contribution in reducing the polluting load of food industry waste and in developing novel added-value products. Plant food residues including trimmings and peels might contain a range of enzymes capable of transforming bioorganic molecules, and thus they may have potential uses in several biocatalytic processes, including green organic synthesis, modification of food physicochemical properties, bioremediation, etc. Although the use of bacterial and fungal enzymes has gained attention in studies pertaining to biocatalytic applications, plant enzymes have been given less consideration or even disregarded. Therefore, we investigated the use of a crude peroxidase preparation from solid onion by-products for oxidizing ferulic acid, a widespread phenolic acid, various derivatives of which may occur in food wastes. The highest enzyme activity was observed at a pH value of 4, but considerable activity was retained up to a pH value of 6. Favorable temperatures for increased activity varied between 20-40 degrees C, 30 degrees C being the optimal. Liquid chromatography-mass spectrometry analysis of a homogenate/H(2)O(2)-treated ferulic acid solution showed the formation of a dimer as a major oxidation product. PMID:18930006

  15. Combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, John

    1994-01-01

    An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

  16. Positronium chemistry

    CERN Document Server

    Green, James

    1964-01-01

    Positronium Chemistry focuses on the methodologies, reactions, processes, and transformations involved in positronium chemistry. The publication first offers information on positrons and positronium and experimental methods, including mesonic atoms, angular correlation measurements, annihilation spectra, and statistical errors in delayed coincidence measurements. The text then ponders on positrons in gases and solids. The manuscript takes a look at the theoretical chemistry of positronium and positronium chemistry in gases. Topics include quenching, annihilation spectrum, delayed coincidence

  17. Biocatalytic desulfurization of diesel oil in an air-lift reactor with immobilized Gordonia nitida CYKS1 cells.

    Science.gov (United States)

    Lee, In Su; Bae, Hee-Sung; Ryu, Hee Wook; Cho, Kyung-Suk; Chang, Yong Keun

    2005-01-01

    A new type of air-lift reactor with immobilized Gordonia nitida CYKS1 cells on a fibrous support was designed and used for the biocatalytic desulfurization (BDS) of diesel oil. Its performance was evaluated at different phase ratios of the oil to the aqueous medium (or oil phase fractions) and different sucrose concentrations. When the reaction mixture contained 10% diesel oil (v/v), 61-67% of sulfur was removed as the sulfur content decreased from 202-250 to 76-90 mg L(-1) in 72 h. The sulfur content did not decrease any further because the remaining sulfur compounds were recalcitrant to BDS. During the desulfurization, the strain CYKS1 consumed hydrocarbons in the diesel oil, mainly n-alkanes with 10-26 carbons, as carbon source even though an easily available carbon source, sucrose, was supplied. PMID:15932256

  18. Biocatalytic self-assembly of supramolecular charge-transfer nanostructures based on n-type semiconductor-appended peptides.

    Science.gov (United States)

    Nalluri, Siva Krishna Mohan; Berdugo, Cristina; Javid, Nadeem; Frederix, Pim W J M; Ulijn, Rein V

    2014-06-01

    The reversible in situ formation of a self-assembly building block (naphthalenediimide (NDI)-dipeptide conjugate) by enzymatic condensation of NDI-functionalized tyrosine (NDI-Y) and phenylalanine-amide (F-NH2) to form NDI-YF-NH2 is described. This coupled biocatalytic condensation/assembly approach is thermodynamically driven and gives rise to nanostructures with optimized supramolecular interactions as evidenced by substantial aggregation induced emission upon assembly. Furthermore, in the presence of di-hydroxy/alkoxy naphthalene donors, efficient charge-transfer complexes are produced. The dynamic formation of NDI-YF-NH2 and electronic and H-bonding interactions are analyzed and characterized by different methods. Microscopy (TEM and AFM) and rheology are used to characterize the formed nanostructures. Dynamic nanostructures, whose formation and function are driven by free-energy minimization, are inherently self-healing and provide opportunities for the development of aqueous adaptive nanotechnology. PMID:24788665

  19. Tunneling of redox enzymes to design nano-probes for monitoring NAD(+) dependent bio-catalytic activity.

    Science.gov (United States)

    Akshath, Uchangi Satyaprasad; Bhatt, Praveena

    2016-11-15

    Monitoring of bio-catalytic events by using nano-probes is of immense interest due to unique optical properties of metal nanoparticles. In the present study, tunneling of enzyme activity was achieved using redox cofactors namely oxidized cytochrome-c (Cyt-c) and Co-enzyme-Q (Co-Q) immobilized on Quantum dots (QDs) which acted as a bio-probe for NAD(+) dependent dehydrogenase catalyzed reaction. We studied how electron transfer from substrate to non-native electron acceptors can differentially modify photoluminescence properties of CdTe QDs. Two probes were designed, QD-Ox-Cyt-c and QD-Ox-Co-Q, which were found to quench the fluorescence of QDs. However, formaldehyde dehydrogenase (FDH) catalyzed reduction of Cyt-c and Co-Q on the surface of QDs lead to fluorescence turn-on of CdTe QDs. This phenomenon was successfully used for the detection of HCHO in the range of 0.01-100,000ng/mL (LOD of 0.01ng/mL) using both QD-Ox-Cyt-c (R(2)=0.93) and QD-Ox-Co-Q (R(2)=0.96). Further probe performance and stability in samples like milk, wine and fruit juice matrix were studied and we could detect HCHO in range of 0.001-100,000ng/mL (LOD of 0.001ng/mL) with good stability and sensitivity of probe in real samples (R(2)=0.97). Appreciable recovery and detection sensitivity in the presence of metal ions suggests that the developed nano-probes can be used successfully for monitoring dehydrogenase based bio-catalytic events even in the absence of NAD(+). Proposed method is advantageous over classical methods as clean up/ derivatization of samples is not required for formaldehyde detection. PMID:27179565

  20. Social Chemistry

    OpenAIRE

    Lichtfouse, Eric; Schwarzbauer, Jan; Robert, Didier

    2012-01-01

    International audience This article is both an essay to propose social chemistry as a new scientific discipline, and a preface of the book Environmental Chemistry for a Sustainable World. Environmental chemistry is a fast emerging discipline aiming at the understanding the fate of pollutants in ecosystems and at designing novel processes that are safe for ecosystems. Past pollution should be cleaned, future pollution should be predicted and avoided (Lichtfouse et al., 2005a). Such advices ...

  1. Computational chemistry

    OpenAIRE

    Truhlar, Donald G.; McKoy, Vincent

    2000-01-01

    Computational chemistry has come of age. With significant strides in computer hardware and software over the last few decades, computational chemistry has achieved full partnership with theory and experiment as a tool for understanding and predicting the behavior of a broad range of chemical, physical, and biological phenomena. The Nobel Prize award to John Pople and Walter Kohn in 1998 highlighted the importance of these advances in computational chemistry. With massively parallel computers ...

  2. Bioinorganic Chemistry

    OpenAIRE

    Bertini, Ivano; Gray, Harry B.; Lippard, Stephen J.; Valentine, Joan Selverstone

    1994-01-01

    This book covers material that could be included in a one-quarter or one-semester course in bioinorganic chemistry for graduate students and advanced undergraduate students in chemistry or biochemistry. We believe that such a course should provide students with the background required to follow the research literature in the field. The topics were chosen to represent those areas of bioinorganic chemistry that are mature enough for textbook presentation. Although each chapter presents material...

  3. Technetium chemistry

    International Nuclear Information System (INIS)

    Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL)

  4. Hybrid membrane with TiO2 based bio-catalytic nanoparticle suspension system for the degradation of bisphenol-A.

    Science.gov (United States)

    Hou, Jingwei; Dong, Guangxi; Luu, Belinda; Sengpiel, Robert G; Ye, Yun; Wessling, Matthias; Chen, Vicki

    2014-10-01

    The removal of micropollutant in wastewater treatment has become a key environmental challenge for many industrialized countries. One approach is to use enzymes such as laccase for the degradation of micropollutants such as bisphenol-A. In this work, laccase was covalently immobilized on APTES modified TiO2 nanoparticles, and the effects of particle modification on the bio-catalytic performance were examined and optimized. These bio-catalytic particles were then suspended in a hybrid membrane reactor for BPA removal with good BPA degradation efficiency observed. Substantial improvement in laccase stability was achieved in the hybrid system compared with free laccase under simulated harsh industrial wastewater treatment conditions (such as a wide range of pH and presence of inhibitors). Kinetic study provided insight of the effect of immobilization on the bio-degradation reaction. PMID:25084046

  5. Development of a two separate phase submerged biocatalytic membrane reactor for the production of fatty acids and glycerol from residual vegetable oil streams

    International Nuclear Information System (INIS)

    Enzymatic membrane bioreactors (MBR) have been studied for very different applications since many years. Submerged MBR has also been successfully used for treatment of wastewater. In the existing submerged configuration, the membrane works as the separation unit operation while the bioconversion is carried out by microorganisms suspended in the tank reactor. In the present work, a novel approach that combines the concept of biocatalytic membranes and submerged modules is proposed for the treatment of biomass. Lipase enzyme from Candida rugosa has been immobilized in polyethersulphone hollow fiber (PES HF) membrane in order to develop a two separate phase biocatalytic submerged membrane reactor in which the membrane works as both catalytic and separation unit. Furthermore, the submerged biocatalytic membrane reactor is intended for production of valuable components from waste biomass, and different physical, chemical and fluid dynamics has been optimized. Response surface methodology (RSM) has been used to model the operating parameters and Box-Behnken method has been applied to maximize the fatty acids production and optimization. At TMP 80 ± 2 kPa, pH 7.40 ± 0.1, temperature 35 ± 0.5 °C with an axial velocity of 0.07 ± 0.01 ms−1 and organic stirring 89.01 rad s−1 the system showed the global examined value within the experimental scope. The proof of principle using fried cooked oils has been performed in later period. -- Highlights: Catalytic activity of enzyme in submerged condition has been studied. ► Optimization of submerged biocatalytic membrane reactor for production of value added components. ► Waste valorization by membrane reactor in order to minimization of waste. ► Three different waste oil (as waste biomass) has been studied in respect to product generation and different results obtained.

  6. Biocatalytic synthesis of flavones and hydroxyl-small molecules by recombinant Escherichia coli cells expressing the cyanobacterial CYP110E1 gene

    OpenAIRE

    Makino Takuya; Otomatsu Toshihiko; Shindo Kazutoshi; Kitamura Emi; Sandmann Gerhard; Harada Hisashi; Misawa Norihiko

    2012-01-01

    Abstract Background Cyanobacteria possess several cytochrome P450s, but very little is known about their catalytic functions. CYP110 genes unique to cyanaobacteria are widely distributed in heterocyst-forming cyanobacteria including nitrogen-fixing genera Nostoc and Anabaena. We screened the biocatalytic functions of all P450s from three cyanobacterial strains of genus Nostoc or Anabaena using a series of small molecules that contain flavonoids, sesquiterpenes, low-molecular-weight drugs, and...

  7. Biocatalytic Conversion of Avermectin to 4″-Oxo-Avermectin: Improvement of Cytochrome P450 Monooxygenase Specificity by Directed Evolution▿ †

    Science.gov (United States)

    Trefzer, Axel; Jungmann, Volker; Molnár, István; Botejue, Ajit; Buckel, Dagmar; Frey, Gerhard; Hill, D. Steven; Jörg, Mario; Ligon, James M.; Mason, Dylan; Moore, David; Pachlatko, J. Paul; Richardson, Toby H.; Spangenberg, Petra; Wall, Mark A.; Zirkle, Ross; Stege, Justin T.

    2007-01-01

    Discovery of the CYP107Z subfamily of cytochrome P450 oxidases (CYPs) led to an alternative biocatalytic synthesis of 4″-oxo-avermectin, a key intermediate for the commercial production of the semisynthetic insecticide emamectin. However, under industrial process conditions, these wild-type CYPs showed lower yields due to side product formation. Molecular evolution employing GeneReassembly was used to improve the regiospecificity of these enzymes by a combination of random mutagenesis, protein structure-guided site-directed mutagenesis, and recombination of multiple natural and synthetic CYP107Z gene fragments. To assess the specificity of CYP mutants, a miniaturized, whole-cell biocatalytic reaction system that allowed high-throughput screening of large numbers of variants was developed. In an iterative process consisting of four successive rounds of GeneReassembly evolution, enzyme variants with significantly improved specificity for the production of 4″-oxo-avermectin were identified; these variants could be employed for a more economical industrial biocatalytic process to manufacture emamectin. PMID:17483257

  8. Good chemistry

    OpenAIRE

    Petsko, Gregory A

    2004-01-01

    The subject matter in chemistry courses reflects almost nothing of the issues that chemists are interested in. It is important to formulate a set of topics - and a Medical College Admissions Test reflecting them - that would leave chemistry departments no choice but to change their teaching.

  9. Quantum chemistry

    CERN Document Server

    Lowe, John P

    1993-01-01

    Praised for its appealing writing style and clear pedagogy, Lowe's Quantum Chemistry is now available in its Second Edition as a text for senior undergraduate- and graduate-level chemistry students. The book assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry, thus enabling students to comprehend much of the current chemical literature in which quantum chemical methods or concepts are used as tools. The book begins with a six-chapter introduction of standard one-dimensional systems, the hydrogen atom,

  10. Materials Chemistry

    CERN Document Server

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  11. Introductory Chemistry

    OpenAIRE

    Baron, Mark; Gonzalez-Rodriguez, Jose; Stevens, Gary; Gray, Nathan; Atherton, Thomas; Winn, Joss

    2010-01-01

    Teaching and Learning resources for the 1st Year Introductory Chemistry course (Forensic Science). 30 credits. These are Open Educational Resources (OER), made available for re-use under a Creative Commons license.

  12. Analytical chemistry

    International Nuclear Information System (INIS)

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

  13. Cluster Chemistry

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Cansisting of eight scientists from the State Key Laboratory of Physical Chemistry of Solid Surfaces and Xiamen University, this creative research group is devoted to the research of cluster chemistry and creation of nanomaterials.After three-year hard work, the group scored a series of encouraging progresses in synthesis of clusters with special structures, including novel fullerenes, fullerene-like metal cluster compounds as well as other related nanomaterials, and their properties study.

  14. Green Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Collison, Melanie

    2011-05-15

    Green chemistry is the science of chemistry used in a way that will not use or create hazardous substances. Dr. Rui Resendes is working in this field at GreenCentre Canada, an offshoot of PARTEQ Innovations in Kingston, Ontario. GreenCentre's preliminary findings suggest their licensed product {sup S}witchable Solutions{sup ,} featuring 3 classes of solvents and a surfactant, may be useful in bitumen oil sands extraction.

  15. Biocatalytic Properties and Structural Analysis of Eugenol Oxidase from Rhodococcus jostii RHA1: A Versatile Oxidative Biocatalyst.

    Science.gov (United States)

    Nguyen, Quoc-Thai; de Gonzalo, Gonzalo; Binda, Claudia; Rioz-Martínez, Ana; Mattevi, Andrea; Fraaije, Marco W

    2016-07-15

    Eugenol oxidase (EUGO) from Rhodococcus jostii RHA1 had previously been shown to convert only a limited set of phenolic compounds. In this study, we have explored the biocatalytic potential of this flavoprotein oxidase, resulting in a broadened substrate scope and a deeper insight into its structural properties. In addition to the oxidation of vanillyl alcohol and the hydroxylation of eugenol, EUGO can efficiently catalyze the dehydrogenation of various phenolic ketones and the selective oxidation of a racemic secondary alcohol-4-(1-hydroxyethyl)-2-methoxyphenol. EUGO was also found to perform the kinetic resolution of a racemic secondary alcohol. Crystal structures of the enzyme in complexes with isoeugenol, coniferyl alcohol, vanillin, and benzoate have been determined. The catalytic center is a remarkable solvent-inaccessible cavity on the si side of the flavin cofactor. Structural comparison with vanillyl alcohol oxidase from Penicillium simplicissimum highlights a few localized changes that correlate with the selectivity of EUGO for phenolic substrates bearing relatively small p-substituents while tolerating o-methoxy substituents. PMID:27123962

  16. Radiation Chemistry

    Science.gov (United States)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  17. Quantum chemistry

    CERN Document Server

    Lowe, John P

    2006-01-01

    Lowe's new edition assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry. It can serve as a primary text in quantum chemistry courses, and enables students and researchers to comprehend the current literature. This third edition has been thoroughly updated and includes numerous new exercises to facilitate self-study and solutions to selected exercises.* Assumes little initial mathematical or physical sophistication, developing insights and abilities in the context of actual problems* Provides thorough treatment

  18. Polymer Chemistry

    Science.gov (United States)

    Williams, Martha; Roberson, Luke; Caraccio, Anne

    2010-01-01

    This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

  19. Organic chemistry

    International Nuclear Information System (INIS)

    The activities of the mycotoxin research group are discussed. This includes the isolation and structure determination of mycotoxins, plant products, the biosyntheris of mycotoxins, the synthesis and characteristics of steroids, the synthesis and mechanistic aspects of heterocyclic chemistry and the functionality of steroids over long distances. Nmr spectra and mass spectroscopy are some of the techniques used

  20. Reinventing Chemistry

    OpenAIRE

    Whitesides, George McClelland

    2015-01-01

    Chemistry is in a period of change, from an era focused on molecules and reactions, to one in which manipulations of systems of molecules and reactions will be essential parts of controlling larger systems. This Essay traces paths from the past to possible futures.

  1. Chemistry Notes

    Science.gov (United States)

    School Science Review, 1972

    1972-01-01

    Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

  2. Fine chemistry

    International Nuclear Information System (INIS)

    The 1988 progress report of the Fine Chemistry laboratory (Polytechnic School, France) is presented. The research programs are centered on the renewal of the organic chemistry most important reactions and on the invention of new, highly efficient and highly selective reactions, by applying low cost reagents and solvents. An important research domain concerns the study and fabrication of new catalysts. They are obtained by means of the reactive sputtering of the metals and metal oxydes thin films. The Monte Carlo simulations of the long-range electrostatic interaction in a clay and the obtention of acrylamides from anhydrous or acrylic ester are summarized. Moreover, the results obtained in the field of catalysis are also given. The published papers and the congress communications are included

  3. Organometallic chemistry

    OpenAIRE

    Bashkin, James K.; M.L.H. Green; Dr. M. L. H. Green

    1982-01-01

    Transition metal organometallic chemistry is a rapidly expanding field, which has an important relationship to industrial problems of petrochemical catalysis. This thesis describes studies of fundamental organometallic reaction processes, such as C-H and C-C bond formation and cleavage, and investigations of the structure and bonding of organometallic compounds. A number of techniques were used to pursue these studies, including synthesis, X-ray crystallography, and semi-em...

  4. Disk Chemistry*

    OpenAIRE

    Thi Wing-Fai

    2015-01-01

    The chemical species in protoplanetary disks react with each other. The chemical species control part of the thermal balance in those disks. How the chemistry proceeds in the varied conditions encountered in disks relies on detailed microscopic understanding of the reactions through experiments or theoretical studies. This chapter strives to summarize and explain in simple terms the different types of chemical reactions that can lead to complex species. The first part of the chapter deals wit...

  5. Interstellar chemistry

    OpenAIRE

    Klemperer, William

    2006-01-01

    In the past half century, radioastronomy has changed our perception and understanding of the universe. In this issue of PNAS, the molecular chemistry directly observed within the galaxy is discussed. For the most part, the description of the molecular transformations requires specific kinetic schemes rather than chemical thermodynamics. Ionization of the very abundant molecular hydrogen and atomic helium followed by their secondary reactions is discussed. The rich variety of organic species o...

  6. Analytical chemistry

    International Nuclear Information System (INIS)

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

  7. Computational chemistry

    Science.gov (United States)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  8. Green chemistry

    International Nuclear Information System (INIS)

    A grand challenge facing government, industry, and academia in the relationship of our technological society to the environment is reinventing the use of materials. To address this challenge, collaboration from an interdisciplinary group of stakeholders will be necessary. Traditionally, the approach to risk management of materials and chemicals has been through inerventions intended to reduce exposure to materials that are hazardous to health and the environment. In 1990, the Pollution Prevention Act encouraged a new tact-elimination of hazards at the source. An emerging approach to this grand challenge seeks to embed the diverse set of environmental perspectives and interests in the everyday practice of the people most responsible for using and creating new materials--chemists. The approach, which has come to be known as Green Chemistry, intends to eliminate intrinsic hazard itself, rather than focusing on reducing risk by minimizing exposure. This chapter addresses the representation of downstream environmental stakeholder interests in the upstream everyday practice that is reinventing chemistry and its material inputs, products, and waste as described in the '12 Principles of Green Chemistry'

  9. Green chemistry

    International Nuclear Information System (INIS)

    The depletion of world fossil fuel reserves and the involvement of greenhouse gases in the global warming has led to change the industrial and energy policies of most developed countries. The goal is now to reserve petroleum to the uses where it cannot be substituted, to implement renewable raw materials obtained from plants cultivation, and to consider the biodegradability of molecules and of manufactured objects by integrating the lifetime concept in their expected cycle of use. The green chemistry includes the design, development and elaboration of chemical products and processes with the aim of reducing or eliminating the use and generation of harmful compounds for the health and the environment, by adapting the present day operation modes of the chemical industry to the larger framework of the sustainable development. In addition to biofuels, this book reviews the applications of green chemistry in the different industrial processes in concern. Part 1 presents the diversity of the molecules coming from renewable carbon, in particular lignocellulose and the biotechnological processes. Part 2 is devoted to materials and treats of the overall available technological solutions. Part 3 focusses on functional molecules and chemical intermediates, in particular in sugar- and fats-chemistry. Part 4 treats of biofuels under the aspects of their production and use in today's technologies. The last part deals with the global approaches at the environmental and agricultural levels. (J.S.)

  10. Surface chemistry

    CERN Document Server

    Desai, KR

    2008-01-01

    The surface Chemistry of a material as a whole is crucially dependent upon the Nature and type of surfaces exposed on crystallites. It is therefore vitally important to independently Study different, well - defined surfaces through surface analytical techniques. In addition to composition and structure of surface, the subject also provides information on dynamic light scattering, micro emulsions, colloid Stability control and nanostructures. The present book endeavour to bring before the reader that the understanding and exploitation of Solid state phenomena depended largely on the ability to

  11. Hypercarbon chemistry

    International Nuclear Information System (INIS)

    This text points out the emerging significance of higher-valent carbon compounds. It describes the compounds of carbon with coordination numbers greater than four and explores the delocalized bonds of π aromatic molecules as a basis for rational description of orbitals; localized multicentered orbitals; the interactions of metallic ions with other atoms and molecules; the skeletal electron counts as a guide for synthesis; and the isolobal concept. Illustrated are the ways in which these subjects bring together structure and reactivity in the great diversity of novel carbon chemistry and its relationship to that of boron, lithium, hydrogen, the metals, and others

  12. Theoretical chemistry periodicities in chemistry and biology

    CERN Document Server

    Eyring, Henry

    1978-01-01

    Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin

  13. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  14. Cyclodextrin chemistry

    International Nuclear Information System (INIS)

    The chemistry of cyclodextrins was studied. This study included synthesising some cyclodextrin derivatives, preparing selected inclusion complexes with cyclodextrin and investigating the effects of gamma irradiation on cyclodextrins and certain linear oligosaccharides. This report presents a brief review of the structure and properties of cyclodextrins, the synthesis of cyclodextrin derivatives, their complexation and applications. This is followed by a description of the synthesis of some cyclodextrin derivatives and the preparation of inclusion complexes of cyclodextrin with some organic compounds. Finally, the effects of gamma irradiation on cyclodextrins, some of their derivatives and certain structurally related carbohydrates are discussed. The gamma irradiation studies were carried out for two reasons: to study the effects of gamma irradiation on cyclodextrins and their derivatives; and to investigate selectivity during the gamma irradiation of cyclodextrin derivatives

  15. Science Update: Inorganic Chemistry

    Science.gov (United States)

    Rawls, Rebecca

    1978-01-01

    This first in a series of articles describing the state of the art of various branches of chemistry reviews inorganic chemistry, including bioinorganic, photochemistry, organometallic, and solid state chemistries. (SL)

  16. Why Teach Environmental Chemistry?

    Science.gov (United States)

    Gardner, Marjorie H.

    1974-01-01

    Discusses the importance of teaching environmental chemistry in secondary school science classes, and outlines five examples of environmental chemistry problems that focus on major concepts of chemistry and have critical implications for human survival and well-being. (JR)

  17. Public perception of chemistry

    OpenAIRE

    Stražar, Alenka

    2015-01-01

    The thesis deals with the perception of chemistry among the public, which reflects the stereotypes that people have about chemistry. It presents the existing classification of stereotypes about chemistry and their upgrade. An analysis of movies that reflect the existing perception of chemistry in the public is written. Literature on selected aspects of the application of chemistry in movies is collected and analyzed. A qualification of perception of chemistry in the movies is presented based ...

  18. Science Update: Inorganic Chemistry.

    Science.gov (United States)

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  19. Trace Chemistry

    Science.gov (United States)

    Radhakrishnan, Krishnan; Whitefield, Philip

    1999-01-01

    The goals of the trace chemistry group were to identify the processes relevant to aerosol and aerosol precursor formation occurring within aircraft gas turbine engines; that is, within the combustor, turbine, and nozzle. The topics of discussion focused on whether the chemistry of aerosol formation is homogeneous or heterogeneous; what species are important for aerosol and aerosol precursor formation; what modeling/theoretical activities to pursue; what experiments to carry out that both support modeling activities and elucidate fundamental processes; and the role of particulates in aerosol and aerosol precursor formation. The consensus of the group was that attention should be focused on SO2, SO3, and aerosols. Of immediate concern is the measurement of the concentration of the species SO3, SO2, H2SO4 OH, HO2, H2O2, O, NO, NO2, HONO, HNO3, CO, and CO2 and particulates in various engines, both those currently in use and those in development. The recommendation was that concentration measurements should be made at both the combustor exit and the engine exit. At each location the above species were classified into one of four categories of decreasing importance, Priority I through IV, as follows: Combustor exit: Priority I species - SO3:SO2 ratio, SO3, SO2, and particulates; Priority II species: OH and O; Priority III species - NO and NO2; and Priority IV species - CO and CO2. For the Engine exit: Priority I species - SO3:SO2 ratio, SO3, SO2,H2SO4, and particulates; Priority II species: OH,HO2, H2O2, and O; Priority III species - NO, NO2, HONO, and HNO3; and Priority IV species - CO and CO2. Table I summarizes the anticipated concentration range of each of these species. For particulate matter, the quantities of interest are the number density, size distribution, and composition. In order to provide data for validating multidimensional reacting flow models, it would be desirable to make 2-D, time-resolved measurements of the concentrations of the above species and

  20. Migration chemistry

    International Nuclear Information System (INIS)

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional KD concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  1. Biocatalytic Synthesis of Vanillin

    OpenAIRE

    Li, Tao; Rosazza, John P. N.

    2000-01-01

    The conversions of vanillic acid and O-benzylvanillic acid to vanillin were examined by using whole cells and enzyme preparations of Nocardia sp. strain NRRL 5646. With growing cultures, vanillic acid was decarboxylated (69% yield) to guaiacol and reduced (11% yield) to vanillyl alcohol. In resting Nocardia cells in buffer, 4-O-benzylvanillic acid was converted to the corresponding alcohol product without decarboxylation. Purified Nocardia carboxylic acid reductase, an ATP and NADPH-dependent...

  2. The Biocatalytic Desulfurization Project

    Energy Technology Data Exchange (ETDEWEB)

    David Nunn; James Boltz; Philip M. DiGrazia; Larry Nace

    2006-03-03

    The material in this report summarizes the Diversa technical effort in development of a biocatalyst for the biodesulfurization of Petro Star diesel as well as an economic report of standalone and combined desulfurization options, prepared by Pelorus and Anvil, to support and inform the development of a commercially viable process. We will discuss goals of the projected as originally stated and their modification as guided by parallel efforts to evaluate commercialization economics and process parameters. We describe efforts to identify novel genes and hosts for the generation of an optimal biocatalyst, analysis of diesel fuels (untreated, chemically oxidized and hydrotreated) for organosulfur compound composition and directed evolution of enzymes central to the biodesulfurization pathway to optimize properties important for their use in a biocatalyst. Finally we will summarize the challenges and issues that are central to successful development of a viable biodesulfurization process.

  3. THE BIOCATALYTIC DESULFURIZATION PROJECT

    Energy Technology Data Exchange (ETDEWEB)

    Steven E. Bonde; David Nunn

    2003-01-01

    During the first quarter of the Biological Desulfurization project several activities were pursued. A project kickoff meeting was held at the Diversa facility in San Diego, CA. Activities that were in process before the meeting and begun afterwards by Diversa Corporation and Petro Star Inc. include: Technology transfer in the form of information generated by Enchira to Diversa, the purchase and installation of equipment by Diversa, development of synthetic methods and preparation of organo-sulfur substrates for use in determining enzyme activities, production of extract via Petro Star's CED process, detailed analysis of Petro Star Inc. diesel and CED extract, and several activities in molecular biology. Diversa Corporation, in the area of molecular biology, engaged in several activities in support of the task list of the contract. These included: construction of a genomic library; development and utilization of a sequence-based gene discovery effort; a parallel discovery approach based on functional expression of enzymes with the ability to oxidize organosulfur compounds. Biodesulfurization genes have already been identified and are being sequenced and subcloned for expression in heterologous biological hosts. Diversa has evaluated and adapted assays developed by Enchira used to assess the activities of DBT and DBTO{sub 2} monooxygenases. Finally, Diversa personnel have developed two novel selection/screen strategies for the improvement of biocatalyst strains by directed evolution.

  4. Biocatalytic weapons against micropollutants

    OpenAIRE

    Agathos, Spiros N.; Environmental Microbiology and Biotechnology in the frame of the Knowledge-Based Bio and Green Economy (EMB2012)

    2012-01-01

    Emerging organic contaminants (EOCs) such as pharmaceuticals and personal care products (PPCPs) are present in areas of significant urbanization and affect treated and untreated wastewater, groundwater, drinking water as well as associated environmental matrices like sludges and sediments. The occurrence of these compounds at very low but environmentally relevant concentrations has earned them the collective term “micropollutants” while an important subgroup is causing concern because of t...

  5. Industrial Chemistry and School Chemistry: Making Chemistry Studies More Relevant

    Science.gov (United States)

    Hofstein, Avi; Kesner, Miri

    2006-01-01

    In this paper, we present the development and implementation over the period of more than 15 years of learning materials focusing on industrial chemistry as the main theme. The work was conducted in the Department of Science Teaching at the Weizmann Institute of Science, Israel. The project's general goal was to teach chemistry concepts in the…

  6. From Matter to Life:Chemistry?Chemistry!

    Institute of Scientific and Technical Information of China (English)

    Jean-Marie; LEHN

    2007-01-01

    1 Results Animate as well as inanimate matter,living organisms as well as materials,are formed of molecules and of the organized entities resulting from the interaction of molecules with each other.Chemistry provides the bridge between the molecules of inanimate matter and the highly complex molecular architectures and systems which make up living organisms. Synthetic chemistry has developed a very powerful set of methods for constructing ever more complex molecules.Supramolecular chemistry seeks to con...

  7. Green chemistry: A tool in Pharmaceutical Chemistry

    OpenAIRE

    Smita Talaviya; Falguni Majumdar

    2012-01-01

    Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceut...

  8. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    Science.gov (United States)

    Burns, Mary Sue

    2001-01-01

    Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

  9. Crevice chemistry estimation from bulk water chemistry

    International Nuclear Information System (INIS)

    Since the first PWR plant in Japan started commercial operation in 1970, 22 plants are running in Japan as of the end of 1994. The main purpose of secondary water chemistry control is to minimize the corrosion possibility of the secondary system equipment, especially steam generators (SG). To achieve this objective, much effort has been concentrated on improving secondary water chemistry control. As a result of this effort, the recent secondary water chemistry in Japanese plants is well maintained in every stage of operation. However, to ensure and improve the reliability of SG, it is necessary to control crevice environments, which are located at tube/tube support plate intersections and under the sludge pile on the tube sheet. According to recent crevice monitoring examination results, the concentration behavior impurities in SG bulk water at the crevice is different for each species, and SG bulk water and crevice chemical compositions are not always equal. From these results, to control the crevice chemistry, improving bulk water chemistry control methods and a new type of molar ratio control index is needed. This paper introduces a brief summary of a recent crevice chemistry evaluation technique and bulk water chemistry control method, which is employed for crevice chemistry control, based on crevice monitoring examination results

  10. Green chemistry: A tool in Pharmaceutical Chemistry

    Directory of Open Access Journals (Sweden)

    Smita Talaviya

    2012-07-01

    Full Text Available Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceuticals is to utilize eco-friendly, non-hazardous, reproducible and efficient solvents and catalysts in synthesis of drug molecules, drug intermediates and in researches involving synthetic chemistry. Microwave synthesis is also an important tool of green chemistry by being an energy efficient process.

  11. Organometallic Chemistry of Molybdenum.

    Science.gov (United States)

    Lucas, C. Robert; Walsh, Kelly A.

    1987-01-01

    Suggests ways to avoid some of the problems students have learning the principles of organometallic chemistry. Provides a description of an experiment used in a third-year college chemistry laboratory on molybdenum. (TW)

  12. CHINESE JOURNAL OF CHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Chinese Journal of Chemistry is an international journal published in English by the Chinese Chemical Society with its editorial office hosted by Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.

  13. Environmental chemistry: Volume A

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.

    1999-08-01

    This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.

  14. Frontiers in Gold Chemistry

    OpenAIRE

    Mohamed, Ahmed A.

    2015-01-01

    Basic chemistry of gold tells us that it can bond to sulfur, phosphorous, nitrogen, and oxygen donor ligands. The Frontiers in Gold Chemistry Special Issue covers gold complexes bonded to the different donors and their fascinating applications. This issue covers both basic chemistry studies of gold complexes and their contemporary applications in medicine, materials chemistry, and optical sensors. There is a strong belief that aurophilicity plays a major role in the unending applications of g...

  15. Green Chemistry and Education.

    Science.gov (United States)

    Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

    2000-01-01

    Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

  16. Environmental Chemistry Activities.

    Science.gov (United States)

    Jackland, Thomas; And Others

    The authors of this curriculum supplement believe in a laboratory approach to chemistry and express the feeling that environmental chemistry provides the students an opportunity to apply theoretical chemistry to important practical problems. There are eighteen activities presented, each accompanied with behavioral objectives, one or more suggested…

  17. Facets of coordination chemistry

    CERN Document Server

    Agarwala, BV

    1993-01-01

    A concise account of coordination chemistry since its inception is given here together with some of the newer significant facets. This book covers a broad spectrum of various topics on Environment, Cyclic Voltammetry, Chromatography, Metal Complexes of biological interest, Alkoxides, NMR spectroscopy and others. These are useful to the scientific community engaged in the field of Inorganic Chemistry and Analytical Chemistry.

  18. Biocatalytic Synthesis of Flavor Ester “Pentyl Valerate” Using Candida rugosa Lipase Immobilized in Microemulsion Based Organogels: Effect of Parameters and Reusability

    Directory of Open Access Journals (Sweden)

    Tripti Raghavendra

    2014-01-01

    Full Text Available Pentyl valerate was synthesized biocatalytically using Candida rugosa lipase (CRL immobilized in microemulsion based organogels (MBGs. The optimum conditions were found to be pH 7.0, temperature of 37°C, ratio of concentration of water to surfactant (Wo of 60, and the surfactant sodium bis-2-(ethylhexylsulfosuccinate (AOT for MBG preparation. Although kinetic studies revealed that the enzyme in free form had high affinity towards substrates (Km = 23.2 mM for pentanol and 76.92 mM for valeric acid whereas, after immobilization, the Km values increased considerably (74.07 mM for pentanol and 83.3 mM for valeric acid resulting in a slower reaction rate, the maximum conversion was much higher in case of immobilized enzyme (~99% as compared to free enzyme (~19%. Simultaneous effects of important parameters were studied using response surface methodology (RSM conjugated with Box-Behnken design (BBD with five variables (process parameters, namely, enzyme concentration, initial water content (Wo, solvent used for MBG preparation, substrate ratio and time, and response as the final product formation, that is, pentyl valerate (%. The MBGs were reused for 10 consecutive cycles for ester synthesis. Efficacy of AOT/isooctane as dehydrating agent for extracting excess water from MBGs was found to exert a positive effect on the esterification reaction.

  19. Combination of deep eutectic solvent and ionic liquid to improve biocatalytic reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cell.

    Science.gov (United States)

    Xu, Pei; Du, Peng-Xuan; Zong, Min-Hua; Li, Ning; Lou, Wen-Yong

    2016-01-01

    The efficient anti-Prelog asymmetric reduction of 2-octanone with Acetobacter pasteurianus GIM1.158 cells was successfully performed in a biphasic system consisting of deep eutectic solvent (DES) and water-immiscible ionic liquid (IL). Various DESs exerted different effects on the synthesis of (R)-2-octanol. Choline chloride/ethylene glycol (ChCl/EG) exhibited good biocompatibility and could moderately increase the cell membrane permeability thus leading to the better results. Adding ChCl/EG increased the optimal substrate concentration from 40 mM to 60 mM and the product e.e. kept above 99.9%. To further improve the reaction efficiency, water-immiscible ILs were introduced to the reaction system and an enhanced substrate concentration (1.5 M) was observed with C4MIM·PF6. Additionally, the cells manifested good operational stability in the reaction system. Thus, the efficient biocatalytic process with ChCl/EG and C4MIM·PF6 was promising for efficient synthesis of (R)-2-octanol. PMID:27185089

  20. American Association for Clinical Chemistry

    Science.gov (United States)

    ... indispensable patient care tool. Learn more IN CLINICAL CHEMISTRY ddPCR Quantification of Lymphoma Mutations Researchers have developed ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  1. The New Color of Chemistry: Green Chemistry

    Directory of Open Access Journals (Sweden)

    Zuhal GERÇEK

    2012-01-01

    Full Text Available Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provide a solution for this requirement, green chemistry rules and under standings should be primarily taken in the university curriculum and at all educational levels.

  2. Surface chemistry essentials

    CERN Document Server

    Birdi, K S

    2013-01-01

    Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

  3. Fundamentals of reactor chemistry

    International Nuclear Information System (INIS)

    In the Nuclear Engineering School of JAERI, many courses are presented for the people working in and around the nuclear reactors. The curricula of the courses contain also the subject material of chemistry. With reference to the foreign curricula, a plan of educational subject material of chemistry in the Nuclear Engineering School of JAERI was considered, and the fundamental part of reactor chemistry was reviewed in this report. Since the students of the Nuclear Engineering School are not chemists, the knowledge necessary in and around the nuclear reactors was emphasized in order to familiarize the students with the reactor chemistry. The teaching experience of the fundamentals of reactor chemistry is also given. (author)

  4. Annual report 1985 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All particles and reports published and lectures given in 1985 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  5. Annual report 1984 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry , environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  6. Annual Report 1984. Chemistry Department

    OpenAIRE

    Funck, Jytte; Nielsen, Ole John

    1985-01-01

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general.

  7. The New Color of Chemistry: Green Chemistry

    OpenAIRE

    Zuhal GERÇEK

    2012-01-01

    Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provid...

  8. Philosophy of Chemistry or Philosophy with Chemistry?

    OpenAIRE

    Bernadette Bensaude-Vincent

    2014-01-01

    Chemistry deserves more philosophical attention not so much to do justice to a long-neglected science or to enhance its cultural prestige, but to undermine a number of taken-for-granted assumptions about scientific rationality and more importantly to diversify our metaphysical views of nature and reality. In brief, this paper does not make the case for a philosophy of chemistry. It rather urges philosophers of science to listen to chemists and discuss what they learn from them. Because over t...

  9. Green chemistry at work

    Energy Technology Data Exchange (ETDEWEB)

    Frost, J. [Michigan State Univ., East Lansing, MI (United States)

    1994-12-31

    The 1.7 billion pounds of benzene produced each year in the US provide one measure of its utility. At the same time, there are a number of environmental reasons for avoiding the use of benzene in chemical manufacture. Perhaps most compelling: benzene is a potent carcinogen. Scrutiny of many of the chemicals derived from benzene reveals that each molecule contains at least one oxygen atom while benzene completely lacks oxygen atoms. Introduction of oxygen to make up for this lack can require processes that are environmentally problematic. One of the steps used to introduce oxygen atoms during manufacture of adipic acid, a component of Nylon 66, is responsible for 10% of the annual global increase in atmospheric nitrous oxide. This by-product is a causative agent of atmospheric ozone depletion and has been implicated in global warming. With support from EPA and the National Science Foundation, alternative manufacturing processes are being explored. By these new methods, chemicals usually created from benzene are made instead from nontoxic glucose, a component of table sugar. Unlike benzene, glucose is obtained from such renewable resources as plant starch and cellulose. ``Green`` manufacturing routes ideally should lead to chemicals that are economically competitive with chemicals produced by traditional methods. For two chemicals of roughly comparable cost, the consumer or producer can then be realistically expected to choose in favor of the chemical produced by a ``green`` process. Projections indicate that catechol and hydroquinone can be biocatalytically produced from glucose at a cost competitive with current market prices. Synthesis of chemicals from glucose using biocatalysis offers the premise of achieving fundamental environmental improvement while increasing the demand for agricultural products. In the final analysis, what is good for the environment can also be good for American agriculture.

  10. Biosensors in clinical chemistry: An overview

    OpenAIRE

    Sathish Babu Murugaiyan; Ramesh Ramasamy; Niranjan Gopal; Kuzhandaivelu, V.

    2014-01-01

    Biosensors are small devices that employ biological/biochemical reactions for detecting target analytes. Basically, the device consists of a biocatalyst and a transducer. The biocatalyst may be a cell, tissue, enzyme or even an oligonucleotide. The transducers are mainly amperometric, potentiometric or optical. The classification of biosensors is based on (a) the nature of the recognition event or (b) the intimacy between the biocatalyst and the transducer. Bioaffinity and biocatalytic device...

  11. Journal of Business Chemistry

    OpenAIRE

    2013-01-01

    The Journal of Business Chemistry examines issues associated with leadership and management for chemists and managers working in chemical research or industry. This journal is devoted to improving and developing the field of Business Chemistry. The Journal of Business Chemistry publishes peer-reviewed papers (including case studies) and essays. Areas for possible publication in include: leadership issues in the chemical and biochemical industry, such as teamwork, team building, mentoring, coa...

  12. Mathematical Thinking in Chemistry

    OpenAIRE

    José L. Villaveces; Guillermo Restrepo

    2012-01-01

    Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffro...

  13. Elementary physical chemistry

    CERN Document Server

    Linder, Bruno

    2010-01-01

    This book is designed for a one-semester course, for undergraduates, not necessarily chemistry majors, who need to know something about physical chemistry. The emphasis is not on mathematical rigor, but subtleties and conceptual difficulties are not hidden. It covers the essential topics in physical chemistry, including the state of matter, thermodynamics, chemical kinetics, phase and chemical equilibria, introduction to quantum theory, and molecular spectroscopy.

  14. Orbital interactions in chemistry

    CERN Document Server

    Albright, Thomas A; Whangbo, Myung-Hwan

    2013-01-01

    Explains the underlying structure that unites all disciplines in chemistry Now in its second edition, this book explores organic, organometallic, inorganic, solid state, and materials chemistry, demonstrating how common molecular orbital situations arise throughout the whole chemical spectrum. The authors explore the relationships that enable readers to grasp the theory that underlies and connects traditional fields of study within chemistry, thereby providing a conceptual framework with which to think about chemical structure and reactivity problems. Orbital Interactions

  15. The Chemistry Institute

    OpenAIRE

    Fontecave, Marc

    2015-01-01

    Chemistry at the Collège de France has received particular attention over the last few years. After the departures of Profs Jean-Marie Lehn and Jacques Livage, new ambition for developing this discipline has led to the creation of several Chairs: Prof. Marc Fontecave’s Chair of Chemistry of Biological Processes in 2008, Prof. Clément Sanchez’ Chair of Chemistry of Hybrid Materials in 2011, and the Chair of Chemistry of Materials and Energy, which Prof. Jean-Marie Tarascon has held since 2014....

  16. Advances in quantum chemistry

    CERN Document Server

    Sabin, John R

    2013-01-01

    Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features detailed reviews written by leading international researchers. This volume focuses on the theory of heavy ion physics in medicine.Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features

  17. DOE fundamentals handbook: Chemistry

    International Nuclear Information System (INIS)

    This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. This volume contains the following modules: reactor water chemistry (effects of radiation on water chemistry, chemistry parameters), principles of water treatment (purpose; treatment processes [ion exchange]; dissolved gases, suspended solids, and pH control; water purity), and hazards of chemicals and gases (corrosives [acids, alkalies], toxic compounds, compressed gases, flammable/combustible liquids)

  18. Group theory and chemistry

    CERN Document Server

    Bishop, David M

    1993-01-01

    Group theoretical principles are an integral part of modern chemistry. Not only do they help account for a wide variety of chemical phenomena, they simplify quantum chemical calculations. Indeed, knowledge of their application to chemical problems is essential for students of chemistry. This complete, self-contained study, written for advanced undergraduate-level and graduate-level chemistry students, clearly and concisely introduces the subject of group theory and demonstrates its application to chemical problems.To assist chemistry students with the mathematics involved, Professor Bishop ha

  19. Biocatalytic synthesis of flavones and hydroxyl-small molecules by recombinant Escherichia coli cells expressing the cyanobacterial CYP110E1 gene

    Directory of Open Access Journals (Sweden)

    Makino Takuya

    2012-07-01

    Full Text Available Abstract Background Cyanobacteria possess several cytochrome P450s, but very little is known about their catalytic functions. CYP110 genes unique to cyanaobacteria are widely distributed in heterocyst-forming cyanobacteria including nitrogen-fixing genera Nostoc and Anabaena. We screened the biocatalytic functions of all P450s from three cyanobacterial strains of genus Nostoc or Anabaena using a series of small molecules that contain flavonoids, sesquiterpenes, low-molecular-weight drugs, and other aromatic compounds. Results Escherichia coli cells carrying each P450 gene that was inserted into the pRED vector, containing the RhFRed reductase domain sequence from Rhodococcus sp. NCIMB 9784 P450RhF (CYP116B2, were co-cultured with substrates and products were identified when bioconversion reactions proceeded. Consequently, CYP110E1 of Nostoc sp. strain PCC 7120, located in close proximity to the first branch point in the phylogenetic tree of the CYP110 family, was found to be promiscuous for the substrate range mediating the biotransformation of various small molecules. Naringenin and (hydroxyl flavanones were respectively converted to apigenin and (hydroxyl flavones, by functioning as a flavone synthase. Such an activity is reported for the first time in prokaryotic P450s. Additionally, CYP110E1 biotransformed the notable sesquiterpene zerumbone, anti-inflammatory drugs ibuprofen and flurbiprofen (methylester forms, and some aryl compounds such as 1-methoxy and 1-ethoxy naphthalene to produce hydroxylated compounds that are difficult to synthesize chemically, including novel compounds. Conclusion We elucidated that the CYP110E1 gene, C-terminally fused to the P450RhF RhFRed reductase domain sequence, is functionally expressed in E. coli to synthesize a robust monooxygenase, which shows promiscuous substrate specificity (affinity for various small molecules, allowing the biosynthesis of not only flavones (from flavanones but also a variety of

  20. Synthesis and characterization of biocatalytic γ-Fe2O3@SiO2 particles as recoverable bioreactors.

    Science.gov (United States)

    Vaz, A M; Serrano-Ruiz, D; Laurenti, M; Alonso-Cristobal, P; Lopez-Cabarcos, E; Rubio-Retama, J

    2014-02-01

    In this work, we present a suitable methodology to produce magnetically recoverable bioreactors based on enzymes, which are covalently attached on the surface of iron oxide@silica nanoparticles. In order to produce this system, iron oxide clusters with a mean diameter of 68 nm were covered with silica. This strategy yields spherical γ-Fe2O3@SiO2 cluster@shell nanoparticles with a mean diameter of 200 nm which present magnetic responsiveness and enhanced stability. The surface of these nanoparticles was modified into two steps with the aim to obtain carboxylic functional groups, which were activated to react with the enzyme glucose oxidase (GOx) that was thus immobilized on the surface of the nanoparticles. The objective of this chemistry at the nanoparticles interface is to produce magnetic-responsive bioreactors. The enzymatic activity was evaluated by using the recoverable bioreactors as part of an amperometric biosensor. These measurements allowed determining the stability, catalytic activity and the amount of enzyme immobilized on the surface of the nanoparticles. Furthermore, the functionalized nanoparticles can be recovered by applying an external magnetic field, which allows them to be employed in chemical processes where the recovery of the biocatalyst is important. PMID:24161502

  1. Open access and medicinal chemistry

    OpenAIRE

    Swain Chris

    2007-01-01

    Abstract Chemistry Central is a new open access website for chemists publishing peer-reviewed research in chemistry from a range of open access journals. A new addition, Chemistry Central Journal, will cover all of chemistry and will be broken down into discipline-specific sections, and Im delighted that Medicinal Chemistry will be a key discipline in this new journal.

  2. Annual report 1988 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1988 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, chemical reactivity, mineral processing, and general. (author)

  3. Annual report 1986 chemistry department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1986 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, radical chemistral, mineral processing, and general. (author)

  4. Annual report 1989 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1989 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, chemical reactivity, mineral processing, and general. (author)

  5. The Breath of Chemistry

    DEFF Research Database (Denmark)

    Josephsen, Jens

    The present preliminary text is a short thematic presentation in biological inorganic chemistry meant to illustrate general and inorganic (especially coordination) chemistry in biochemistry. The emphasis is on molecular models to explain features of the complicated mechanisms essential to breathing...

  6. Movies in Chemistry Education

    Science.gov (United States)

    Pekdag, Bulent; Le Marechal, Jean-Francois

    2010-01-01

    This article reviews numerous studies on chemistry movies. Movies, or moving pictures, are important elements of multimedia and signify a privileged or motivating means of presenting knowledge. Studies on chemistry movies show that the first movie productions in this field were devoted to university lectures or documentaries. Shorter movies were…

  7. Physical Chemistry of Molecular

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Established in 2009, the group consists of six researchers and more than 70 research assistants and graduate students from the CAS Key Laboratory of Molecular Nanostructures and Nanotechnologies at the CAS Institute of Chemistry.Its research focuses on the physical chemistry involved in molecular assembly, molecular nanostructures, functional nanomaterials and conceptual nano-devices.

  8. Chemistry of americium

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.W.

    1976-01-01

    Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, separation, purification. Author and subject indexes are included. (JCB)

  9. Exercises in Computational Chemistry

    DEFF Research Database (Denmark)

    Spanget-Larsen, Jens

    2016-01-01

    A selection of HyperChem© PC-exercises in computational chemistry. Answers to most questions are appended (Roskilde University 2014-16).......A selection of HyperChem© PC-exercises in computational chemistry. Answers to most questions are appended (Roskilde University 2014-16)....

  10. Titanocene sulfide chemistry

    Czech Academy of Sciences Publication Activity Database

    Horáček, Michal

    2016-01-01

    Roč. 314, MAY 2016 (2016), s. 83-102. ISSN 0010-8545 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 Keywords : titanocene sulfide chemistry * photolysis * titanocene hydrosulfides Ti-(SH)n Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 12.239, year: 2014

  11. Chemistry in Microfluidic Channels

    Science.gov (United States)

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  12. Mathematical Thinking in Chemistry

    Directory of Open Access Journals (Sweden)

    José L. Villaveces

    2012-05-01

    Full Text Available Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffroy's affinity table, Lavoisier's classification of substances and their relationships, Mendeleev's periodic table, Cayley's enumeration of alkanes, Sylvester's association of algebra and chemistry, and Wiener's relationship between molecular structure and boiling points. These examples show that mathematical chemistry has much more than a century of history.

  13. Influences of operating conditions on biocatalytic activity and reusability of Novozym 435 for esterification of free fatty acids with short-chain alcohols:A case study of palm fatty acid distillate

    Institute of Scientific and Technical Information of China (English)

    Sawittree Mulalee; Pongrumpa Srisuwan; Muenduen Phisalaphong

    2015-01-01

    In the present study, the effects of operating conditions on biocatalytic activity and stability of Novozym 435 for repeated-batch biodiesel production from free fatty acid (FFA) were investigated. Thermal deactivation caused by increased operating temperature from 45 to 50 °C could seriously affect the reusability of Novozym 435. The deactivation of Novozym 435 during the esterification of oleic acid with ethanol tended to be stronger than that in the system with methanol. Under the optimal conditions, considering both biocatalytic activity and stability of the enzyme, Novozym 435 could be reused for 13 cycles for biodiesel productions from oleic acid and absolute alcohols (methanol and ethanol) with FFA conversions of at least 90%. The presence of 4%–5%water in ethanol significantly affected the reusability of Novozym 435. Changes in the surface morphology of Novozym 435 during the esterification with various conditions were observed. It was revealed that the reduc-tion in catalytic activity was related to the swel ing degree of the catalyst surface. Additionally, biodiesel produc-tion from low cost renewable feedstocks, such as palm fatty acid distillate (PFAD) and 95%ethanol was examined. The esterification of PFAD with 95%ethanol catalyzed by Novozym 435 in 10-repeated batch operation showed the similar results in FFA conversion as compared to those using oleic acid. Novozym 435 remained active and could maintain 97.6%of its initial conversion after being used for 10 batches.

  14. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    Science.gov (United States)

    Murfin, Brian

    2009-01-01

    Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious and popular Korean dish that can be used to explore many important chemistry concepts,…

  15. Third Chemistry Conference on Recent Trends in Chemistry

    International Nuclear Information System (INIS)

    The third chemistry conference 2011 on recent trends in chemistry was held from October 17-19, 2001 at Islamabad, Pakistan. More than 65 papers and oral presentation. The scope of the conference was wide open and provides and opportunity for participation of broad spectrum of chemists. This forum provided a platform for the dissemination of the latest research followed by discussion pertaining to new trends in chemistry. This con fence covered different aspects of subjects including analytical chemistry, environmental chemistry, polymer chemistry, industrial chemistry, biochemistry and nano chemistry etc. (A.B.)

  16. System approach to chemistry course

    OpenAIRE

    Lorina E. Kruglova; Valentina G. Derendyaeva

    2010-01-01

    The article considers the raise of chemistry profile for engineers and constructors training, discloses the system approach to chemistry course and singles out the most important modules from the course of general chemistry for construction industry.

  17. Annual report 1987 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1987 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, radical chemistry, mineral processing, and general. 13 ills., (author)

  18. Annual report 1982 chemistry department

    International Nuclear Information System (INIS)

    The work going on in the Risoe National Laboratory, Chemistry Department is briefly surveyed by a presentation of all articles and reports published in 1982. The facilities and equipment are barely mentioned. The papers are divided into eight activities: 1. neutron activation analysis 2. analytical- and organic chemistry 3. environmental chemistry 4. polymer chemistry 5. geochemistry 6. radical chemistry 7. poitron annihilation 8. uranium process chemistry. (author)

  19. Moderator Chemistry Program

    International Nuclear Information System (INIS)

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation

  20. Moderator Chemistry Program

    Energy Technology Data Exchange (ETDEWEB)

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  1. Moderator Chemistry Program

    Energy Technology Data Exchange (ETDEWEB)

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department`s moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  2. Annual Report 1984. Chemistry Department

    DEFF Research Database (Denmark)

    Funck, Jytte; Nielsen, Ole John

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, an......, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general.......This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry...

  3. Chemistry in water reactors

    International Nuclear Information System (INIS)

    The international conference Chemistry in Water Reactors was arranged in Nice 24-27/04/1994 by the French Nuclear Energy Society. Examples of technical program areas were primary chemistry, operational experience, fundamental studies and new technology. Furthermore there were sessions about radiation field build-up, hydrogen chemistry, electro-chemistry, condensate polishing, decontamination and chemical cleaning. The conference gave the impression that there are some areas that are going to be more important than others during the next few years to come. Cladding integrity: Professor Ishigure from Japan emphasized that cladding integrity is a subject of great concern, especially with respect to waterside corrosion, deposition and release of crud. Chemistry control: The control of the iron/nickel concentration quotient seems to be not as important as previously considered. The future operation of a nuclear power plant is going to require a better control of the water chemistry than achievable today. One example of this is solubility control via regulation in BWR. Trends in USA: means an increasing use of hydrogen, minimization of SCC/IASCC, minimization of radiation fields by thorough chemistry control, guarding fuel integrity by minimization of cladding corrosion and minimization of flow assisted corrosion. Stellite replacement: The search for replacement materials will continue. Secondary side crevice chemistry: Modeling and practical studies are required to increase knowledge about the crevice chemistry and how it develops under plant operation conditions. Inhibitors: Inhibitors for IGSCC and IGA as well for the primary- (zinc) as for the secondary side (Ti) should be studied. The effects and mode of operation of the inhibitors should be documented. Chemical cleaning: of heat transfer surfaces will be an important subject. Prophylactic cleaning at regular intervals could be one mode of operation

  4. Mathematics for physical chemistry

    CERN Document Server

    Mortimer, Robert G

    2013-01-01

    Mathematics for Physical Chemistry is the ideal supplementary text for practicing chemists and students who want to sharpen their mathematics skills while enrolled in general through physical chemistry courses. This book specifically emphasizes the use of mathematics in the context of physical chemistry, as opposed to being simply a mathematics text. This 4e includes new exercises in each chapter that provide practice in a technique immediately after discussion or example and encourage self-study. The early chapters are constructed around a sequence of mathematical topics, wit

  5. Computational quantum chemistry website

    International Nuclear Information System (INIS)

    This report contains the contents of a web page related to research on the development of quantum chemistry methods for computational thermochemistry and the application of quantum chemistry methods to problems in material chemistry and chemical sciences. Research programs highlighted include: Gaussian-2 theory; Density functional theory; Molecular sieve materials; Diamond thin-film growth from buckyball precursors; Electronic structure calculations on lithium polymer electrolytes; Long-distance electronic coupling in donor/acceptor molecules; and Computational studies of NOx reactions in radioactive waste storage

  6. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 1 covers papers on the advances of gas phase ion chemistry. The book discusses the advances in flow tubes and the measurement of ion-molecule rate coefficients and product distributions; the ion chemistry of the earth's atmosphere; and the classical ion-molecule collision theory. The text also describes statistical methods in reaction dynamics; the state selection by photoion-photoelectron coincidence; and the effects of temperature and pressure in the kinetics of ion-molecule reactions. The energy distribution in the unimolecular decomposition of ions, as well

  7. Experiments in physical chemistry

    CERN Document Server

    Wilson, J M; Denaro, A R

    1968-01-01

    Experiments in Physical Chemistry, Second Edition provides a compilation of experiments concerning physical chemistry. This book illustrates the link between the theory and practice of physical chemistry. Organized into three parts, this edition begins with an overview of those experiments that generally have a simple theoretical background. Part II contains experiments that are associated with more advanced theory or more developed techniques, or which require a greater degree of experimental skill. Part III consists of experiments that are in the nature of investigations wherein these invest

  8. DOE fundamentals handbook: Chemistry

    International Nuclear Information System (INIS)

    The Chemistry Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. The handbook includes information on the atomic structure of matter; chemical bonding; chemical equations; chemical interactions involved with corrosion processes; water chemistry control, including the principles of water treatment; the hazards of chemicals and gases, and basic gaseous diffusion processes. This information will provide personnel with a foundation for understanding the chemical properties of materials and the way these properties can impose limitations on the operation of equipment and systems

  9. Chemistry at large

    OpenAIRE

    Sanders, Jeremy K. M.

    2007-01-01

    A new book introduces young researchers to supramolecular chemistry, starting from the basics and working up to the more complicated aspects of the topic. While the text is inspiring for new graduates, it lacks a critical view.

  10. General Chemistry for Engineers.

    Science.gov (United States)

    Kybett, B. D.

    1982-01-01

    Discusses the relationship between molecular structure, intermolecular forces, and tensile strengths of a polymer and suggests that this is a logical way to introduce polymers into a general chemistry course. (Author/JN)

  11. Bringing chemistry to life

    OpenAIRE

    Boyce, Michael; Bertozzi, Carolyn R.

    2011-01-01

    Bioorthogonal chemistry allows a wide variety of biomolecules to be specifically labeled and probed in living cells and whole organisms. Here we discuss the history of bioorthogonal reactions and some of the most interesting and important advances in the field.

  12. Supplemental instruction in chemistry

    Science.gov (United States)

    Lundeberg, Mary A.

    This study was designed to measure some effects of supplemental instruction in chemistry. Supplemental instruction is a peer-led cooperative learning program that encourages students to develop conceptual understanding by articulating both understandings and misconceptions in a think-aloud fashion. Supplemental instruction was offered three hours weekly outside of class and lab time for students in four classes of General Organic and Biological Chemistry. Over a two-year period 108 students volunteered to participate in this program; 45 students did not participate. As measured by final grades in chemistry and responses to a questionnaire, supplemental instruction was effective in increasing students' achievement in chemistry. Further research is needed to determine the in-depth effects of supplemental instruction on students' learning, problem solving, and self-esteem.

  13. Beauty in chemistry

    Directory of Open Access Journals (Sweden)

    Peter Atkins

    2006-03-01

    Full Text Available Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  14. Beauty in chemistry

    OpenAIRE

    Peter Atkins

    2006-01-01

    Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  15. Magnetism in Chemistry

    Science.gov (United States)

    Brookes, R. W.; McFadyen, W. D.

    1975-01-01

    Discusses the technical aspects of paramagnetism and an electrostatic model called Crystal Field Theory (CFT), very often used in the case of transition metal compounds. Suggests that this discussion be included as an option for college chemistry courses. (MLH)

  16. Enzymes in Analytical Chemistry.

    Science.gov (United States)

    Fishman, Myer M.

    1980-01-01

    Presents tabular information concerning recent research in the field of enzymes in analytic chemistry, with methods, substrate or reaction catalyzed, assay, comments and references listed. The table refers to 128 references. Also listed are 13 general citations. (CS)

  17. Forensic Chemistry Training

    OpenAIRE

    Zuhal GERÇEK

    2012-01-01

    Increasing the types of terrorism and crime nowadays, the importance of the forensic sciences can be bett er understood. Forensic science is the application of the wide spectrum of science to answer the question of legal system. It contains the application of the principles, techniques and methods of basic sciences and its main aim is the determination of the physical facts which are important in legal situations. Forensic chemistry is the branch of chemistry which performs the chemical analy...

  18. Applications of supramolecular chemistry

    CERN Document Server

    Schneider, Hans-Jörg

    2012-01-01

    ""The time is ripe for the present volume, which gathers thorough presentations of the numerous actually realized or potentially accessible applications of supramolecular chemistry by a number of the leading figures in the field. The variety of topics covered is witness to the diversity of the approaches and the areas of implementation…a broad and timely panorama of the field assembling an eminent roster of contributors.""-Jean-Marie Lehn, 1987 Noble Prize Winner in Chemistry

  19. Fundamentals of quantum chemistry

    CERN Document Server

    House, J E

    2004-01-01

    An introduction to the principles of quantum mechanics needed in physical chemistry. Mathematical tools are presented and developed as needed and only basic calculus, chemistry, and physics is assumed. Applications include atomic and molecular structure, spectroscopy, alpha decay, tunneling, and superconductivity. New edition includes sections on perturbation theory, orbital symmetry of diatomic molecules, the Huckel MO method and Woodward/Hoffman rules as well as a new chapter on SCF and Hartree-Fock methods. * This revised text clearly presents basic q

  20. Impact of surface chemistry

    OpenAIRE

    Somorjai, Gabor A.; Li, Yimin

    2010-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized.

  1. Quantitative analysis chemistry

    International Nuclear Information System (INIS)

    This book is about quantitative analysis chemistry. It is divided into ten chapters, which deal with the basic conception of material with the meaning of analysis chemistry and SI units, chemical equilibrium, basic preparation for quantitative analysis, introduction of volumetric analysis, acid-base titration of outline and experiment examples, chelate titration, oxidation-reduction titration with introduction, titration curve, and diazotization titration, precipitation titration, electrometric titration and quantitative analysis.

  2. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation

  3. EPA Environmental Chemistry Laboratory

    Science.gov (United States)

    1993-01-01

    The Environmental Protection Agency's (EPA) Chemistry Laboratory (ECL) is a national program laboratory specializing in residue chemistry analysis under the jurisdiction of the EPA's Office of Pesticide Programs in Washington, D.C. At Stennis Space Center, the laboratory's work supports many federal anti-pollution laws. The laboratory analyzes environmental and human samples to determine the presence and amount of agricultural chemicals and related substances. Pictured, ECL chemists analyze environmental and human samples for the presence of pesticides and other pollutants.

  4. Chemistry and nuclear technology

    International Nuclear Information System (INIS)

    The underlying principles of nuclear sciece and technology as based on the two basic phenomena, namely, radioactivity and nuclear reactions, with their relatively large associated energy changes, are outlined. The most important contributions by chemists in the overall historical development are mentioned and the strong position chemistry has attained in these fields is indicated. It is concluded that chemistry as well as many other scientific discplines (apart from general benefits) have largely benefitted from these nuclear developments

  5. Mathematical problems for chemistry students

    CERN Document Server

    Pota, Gyorgy

    2006-01-01

    Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistry students in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialists of the chemistry-related fields (physicists, mathematicians, biologists, etc.) into the world of the chemical applications. Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, other

  6. Annual report 1983 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1983 are presented. The facilities and equipment are barely mentioned. The activities are divided into nine groups: 1. radioisotope chemistry 2. analytical- and organic chemistry 3. environmental chemistry 4. polymer chemistry 5. geochemistry and waste disposal 6. radical chemstry 7. positron annihilation 8. mineral processing 9. general. (author)

  7. Chemistry beyond positivism.

    Science.gov (United States)

    Brandt, Werner W

    2003-05-01

    Chemistry is often thought to be quite factual, and therefore might be considered close to the "positivist" ideal of a value-free science. A closer look, however, reveals that the field is coupled to the invisible realm of values, meanings, and purpose in various ways, and chemists interact with that realm loosely and unevenly. Tacit knowledge is one important locus of such interactions. We are concerned in this essay with two questions. What is the nature of the knowledge when we are in the early stages of discovery? and In what ways does the hidden reality we are seeking affect our search for an understanding of it? The first question is partly answered by Polanyi's theory of tacit knowledge, while the second one leads us to realize the limitations of our language when discussing "reality"-or certain chemical experimental results. A strictly positivist approach is of little use, but so is the opposite, the complete disregard of facts. The contrast between positivism and non-formulable aspects of scientific reasoning amounts to a paradox that needs to be analyzed and can lead to a "connected" chemistry. This in turn resembles networks described by Schweber and is more concerned than the chemistry "as it is" with aspects such as the image of chemistry, the challenges chemists face as citizens, and chemistry in liberal education. PMID:12796119

  8. An Advanced Organometallic Lab Experiment with Biological Implications: Synthesis and Characterization of Fe[subscript 2](µ-S[subscript 2])(C0)[subscript 6

    Science.gov (United States)

    Barrett, Jacob; Spentzos, Ariana; Works, Carmen

    2015-01-01

    The organometallic complex Fe[subscript 2](µ-S[subscript 2])(CO)[subscript 6] has interesting biological implications. The concepts of bio-organometallic chemistry are rarely discussed at the undergraduate level, but this experiment can start such a conversation and, in addition, teach valuable synthetic techniques. The lab experiment takes a…

  9. Suitability assessment of a continuous process combining thermo-mechano-chemical and bio-catalytic action in a single pilot-scale twin-screw extruder for six different biomass sources.

    Science.gov (United States)

    Vandenbossche, Virginie; Brault, Julien; Hernandez-Melendez, Oscar; Evon, Philippe; Barzana, Eduardo; Vilarem, Gérard; Rigal, Luc

    2016-07-01

    A process has been validated for the deconstruction of lignocellulose on a pilot scale installation using six types of biomass selected for their sustainability, accessibility, worldwide availability, and differences of chemical composition and physical structure. The process combines thermo-mechano-chemical and bio-catalytic action in a single twin-screw extruder. Three treatment phases were sequentially performed: an alkaline pretreatment, a neutralization step coupled with an extraction-separation phase and a bioextrusion treatment. Alkaline pretreatment destructured the wall polymers after just a few minutes and allowed the initial extraction of 18-54% of the hemicelluloses and 9-41% of the lignin. The bioextrusion step induced the start of enzymatic hydrolysis and increased the proportion of soluble organic matter. Extension of saccharification for 24h at high consistency (20%) and without the addition of new enzyme resulted in the production of 39-84% of the potential glucose. PMID:27015021

  10. Biocatalytic ammonolysis of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester: preparation of an intermediate to the dipeptidyl peptidase IV inhibitor Saxagliptin.

    Science.gov (United States)

    Gill, Iqbal; Patel, Ramesh

    2006-02-01

    An efficient biocatalytic method has been developed for the conversion of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester (1) into the corresponding amide (5S)-5-aminocarbonyl-4,5-dihydro-1H-pyrrole-1-carboxylic acid, 1-(1,1-dimethylethyl)ester (2), which is a critical intermediate in the synthesis of the dipeptidyl peptidase IV (DPP4) inhibitor Saxagliptin (3). Candida antartica lipase B mediates ammonolysis of the ester with ammonium carbamate as ammonia donor to yield up to 71% of the amide. The inclusion of Ascarite and calcium chloride as adsorbents for carbon dioxide and ethanol byproducts, respectively, increases the yield to 98%, thereby offering an efficient and practical alternative to chemical routes which yield 57-64%. PMID:16257208

  11. Collaborative Physical Chemistry Projects Involving Computational Chemistry

    Science.gov (United States)

    Whisnant, David M.; Howe, Jerry J.; Lever, Lisa S.

    2000-02-01

    The physical chemistry classes from three colleges have collaborated on two computational chemistry projects using Quantum CAChe 3.0 and Gaussian 94W running on Pentium II PCs. Online communication by email and the World Wide Web was an important part of the collaboration. In the first project, students used molecular modeling to predict benzene derivatives that might be possible hair dyes. They used PM3 and ZINDO calculations to predict the electronic spectra of the molecules and tested the predicted spectra by comparing some with experimental measurements. They also did literature searches for real hair dyes and possible health effects. In the final phase of the project they proposed a synthetic pathway for one compound. In the second project the students were asked to predict which isomer of a small carbon cluster (C3, C4, or C5) was responsible for a series of IR lines observed in the spectrum of a carbon star. After preliminary PM3 calculations, they used ab initio calculations at the HF/6-31G(d) and MP2/6-31G(d) level to model the molecules and predict their vibrational frequencies and rotational constants. A comparison of the predictions with the experimental spectra suggested that the linear isomer of the C5 molecule was responsible for the lines.

  12. Reaction chemistry of cerium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    It is truly ironic that a synthetic organic chemist likely has far greater knowledge of the reaction chemistry of cerium(IV) than an inorganic colleague. Cerium(IV) reagents have long since been employed as oxidants in effecting a wide variety of organic transformations. Conversely, prior to the late 1980s, the number of well characterized cerium(IV) complexes did not extend past a handful of known species. Though in many other areas, interest in the molecular chemistry of the 4f-elements has undergone an explosive growth over the last twenty years, the chemistry of cerium(IV) has for the most part been overlooked. This report describes reactions of cerium complexes and structure.

  13. Chemistry of plutonium revealed

    International Nuclear Information System (INIS)

    In 1941 one goal of the Manhattan Project was to unravel the chemistry of the synthetic element plutonium as rapidly as possible. In this paper the work carried out at Berkeley from the spring of 1942 to the summer of 1945 is described briefly. The aqueous chemistry of plutonium is quite remarkable. Important insights were obtained from tracer experiments, but the full complexity was not revealed until macroscopic amounts (milligrams) became available. Because processes for separation from fission products were based on aqueous solutions, such solution chemistry was emphasized, particularly precipitation and oxidation-reduction behavior. The latter turned out to be unusually intricate when it was discovered that two more oxidation states existed in aqueous solution than had previously been suspected. Further, an equilibrium was rapidly established among the four aqueous oxidation states, while at the same time any three were not in equilibrium. These and other observations made while doing a crash study of a previously unknown element are reported

  14. Introductory quantum chemistry

    International Nuclear Information System (INIS)

    This book on quantum chemistry is primarily intended for university students at the senior undergraduate level. It serves as an aid to the basic understanding of the important concepts of quantum mechanics introduced in the field of chemistry. Various chapters of the book are devoted to the following : (i) Waves and quanta, (ii) Operator concept in quantum chemistry, (iii) Wave mechanics of some simple systems, (iv) Perturbation theory, (v) Many-electron atoms and angular momenta (vi) Molecular orbital theory and its application to the electronic structure of diatomic molecules, (vii) Chemical bonding in polyatomic molecules and (viii) Chemical applications of Hellmann-Feynman theorem. At the end of each chapter, a set of problems is given and the answers to these problems are given at the end of the book. (A.K.)

  15. Mathematics for physical chemistry

    CERN Document Server

    Mortimer, Robert G

    2005-01-01

    Mathematics for Physical Chemistry, Third Edition, is the ideal text for students and physical chemists who want to sharpen their mathematics skills. It can help prepare the reader for an undergraduate course, serve as a supplementary text for use during a course, or serve as a reference for graduate students and practicing chemists. The text concentrates on applications instead of theory, and, although the emphasis is on physical chemistry, it can also be useful in general chemistry courses. The Third Edition includes new exercises in each chapter that provide practice in a technique immediately after discussion or example and encourage self-study. The first ten chapters are constructed around a sequence of mathematical topics, with a gradual progression into more advanced material. The final chapter discusses mathematical topics needed in the analysis of experimental data.* Numerous examples and problems interspersed throughout the presentations * Each extensive chapter contains a preview, objectives, and ...

  16. Progress on Biocatalytic Reaction in Various Ionic Liquid Mediums%不同离子液体反应介质在生物催化中的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    杜伟燕; 李娜; 王寿江

    2012-01-01

      离子液体(ILs)因其独特物理化学性质成为新型反应溶剂和催化剂,在生物催化反应中有着广阔的应用前景。根据不同 ILs 的水溶性,其与水可形成4种反应介质,即微水 ILs 单相体系、亲水性 ILs-水单相体系、疏水性 ILs-水两相体系和 ILs 微乳液体系。本文分别介绍了不同 ILs 反应体系中生物催化剂的催化活性、稳定性和选择性,综述了这些体系中的生物催化反应研究进展。%  Ionic liquids (ILs) are new reaction mediums and catalysts for biocatalytic reaction due to their excellent physical and chemical characteristics. ILs can form 4 kinds of reaction mediums with water based on their water solubility, that is, nearly anhydrous ILs systems, hydrophilic ILs-water systems, hydrophobic ILs-water two-phase systems, and water-in-ILs microemulsions. In this article, the activity, stability and selectivity of biocatalysts in the four ILs-containing mediums are summarized and the research progresses of biocatalytic reaction in the systems are discussed.

  17. Dynamic Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Lisbjerg, Micke

    This thesis is divided into seven chapters, which can all be read individually. The first chapter, however, contains a general introduction to the chemistry used in the remaining six chapters, and it is therefore recommended to read chapter one before reading the other chapters. Chapter 1...... is a general introductory chapter for the whole thesis. The history and concepts of dynamic combinatorial chemistry are described, as are some of the new and intriguing results recently obtained. Finally, the properties of a broad range of hexameric macrocycles are described in detail. Chapter 2 gives...

  18. Cloud chemistry on Jupiter

    OpenAIRE

    Carlson, B. E.; Prather, M. J.; W. B. Rossow

    1987-01-01

    Aqueous chemistry on Uranus affects the atmospheric abundances of NH3 and H2S below the methane cloud base. Here a complete thermochemical equilibrium model for the H2O-NH3-H2S system is presented. Inclusion of H2S increases the aqueous removal of NH3 to 20-30 percent, but aqueous chemistry alone cannot account for the depletion of NH3 in the 150-200-K region of the atmosphere required to fit microwave observations. Formation of NH4SH clouds can account for the observed depletion provided the...

  19. Chemistry of Transactinides

    Science.gov (United States)

    Kratz, J. V.

    In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactinides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112.

  20. Solvent effects in chemistry

    CERN Document Server

    Buncel, Erwin

    2015-01-01

    This book introduces the concepts, theory and experimental knowledge concerning solvent effects on the rate and equilibrium of chemical reactions of all kinds.  It begins with basic thermodynamics and kinetics, building on this foundation to demonstrate how a more detailed understanding of these effects may be used to aid in determination of reaction mechanisms, and to aid in planning syntheses. Consideration is given to theoretical calculations (quantum chemistry, molecular dynamics, etc.), to statistical methods (chemometrics), and to modern day concerns such as ""green"" chemistry, where ut

  1. Nanophotonics and supramolecular chemistry

    Science.gov (United States)

    Ariga, Katsuhiko; Komatsu, Hirokazu; Hill, Jonathan P.

    2013-10-01

    Supramolecular chemistry has become a key area in emerging bottom-up nanoscience and nanotechnology. In particular, supramolecular systems that can produce a photonic output are increasingly important research targets and present various possibilities for practical applications. Accordingly, photonic properties of various supramolecular systems at the nanoscale are important in current nanotechnology. In this short review, nanophotonics in supramolecular chemistry will be briefly summarized by introducing recent examples of control of photonic responses of supramolecular systems. Topics are categorized according to the fundamental actions of their supramolecular systems: (i) self-assembly; (ii) recognition; (iii) manipulation.

  2. Revitalizing chemistry laboratory instruction

    Science.gov (United States)

    McBride, Phil Blake

    This dissertation involves research in three major domains of chemical education as partial fulfillment of the requirements for the Ph.D. program in chemistry at Miami University with a major emphasis on chemical education, and concurrent study in organic chemistry. Unit I, Development and Assessment of a Column Chromatography Laboratory Activity, addresses the domain of Instructional Materials Development and Testing. This unit outlines the process of developing a publishable laboratory activity, testing and revising that activity, and subsequently sharing that activity with the chemical education community. A laboratory activity focusing on the separation of methylene blue and sodium fluorescein was developed to demonstrate the effects of both the stationary and mobile phase in conducting a separation. Unit II, Bringing Industry to the Laboratory, addresses the domain of Curriculum Development and Testing. This unit outlines the development of the Chemistry of Copper Mining module, which is intended for use in high school or undergraduate college chemistry. The module uses the learning cycle approach to present the chemistry of the industrial processes of mining copper to the students. The module includes thirteen investigations (three of which are web-based and ten which are laboratory experiments) and an accompanying interactive CD-ROM, which provides an explanation of the chemistry used in copper mining with a virtual tour of an operational copper mine. Unit III, An Alternative Method of Teaching Chemistry. Integrating Lecture and the Laboratory, is a project that addresses the domain of Research in Student Learning. Fundamental Chemistry was taught at Eastern Arizona College as an integrated lecture/laboratory course that met in two-hour blocks on Monday, Wednesday, and Friday. The students taking this integrated course were compared with students taking the traditional 1-hour lectures held on Monday, Wednesday, and Friday, with accompanying 3-hour lab on

  3. Computational organometallic chemistry

    International Nuclear Information System (INIS)

    In this article, the author highlights the tremendous impact that density functional theory has had on computational chemistry over the last decade. This robust and efficient theoretical technique (for which John Pople and Walter Kohn were awarded the Nobel Prize in 1998) has opened up many new possibilities for chemists, allowing to study large systems with a degree of reliability hitherto uncontemplated. Examples which illustrate how both density functional theory and hybrid method have been successfully used in solving difficult problems in quantum chemistry of catalysis are briefly discussed

  4. Spins in chemistry

    CERN Document Server

    McWeeny, Roy

    2004-01-01

    Originally delivered as a series of lectures, this volume systematically traces the evolution of the ""spin"" concept from its role in quantum mechanics to its assimilation into the field of chemistry. Author Roy McWeeny presents an in-depth illustration of the deductive methods of quantum theory and their application to spins in chemistry, following the path from the earliest concepts to the sophisticated physical methods employed in the investigation of molecular structure and properties. Starting with the origin and development of the spin concept, the text advances to an examination of sp

  5. Atmospheric pseudohalogen chemistry

    OpenAIRE

    Lary, D. J.

    2004-01-01

    There are at least three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. The first is well known, HCN is a product and marker of biomass burning. However, if a detailed ion chemistry of lightning is considered then it is almost certain than in addition to lightning producing NOx, it also produces HOx and HCN. Unlike NOx and HOx, HCN is long-lived and could therefore ...

  6. Chemistry WebBook

    Science.gov (United States)

    SRD 69 NIST Chemistry WebBook (Web, free access)   The NIST Chemistry WebBook contains: Thermochemical data for over 7000 organic and small inorganic compounds; thermochemistry data for over 8000 reactions; IR spectra for over 16,000 compounds; mass spectra for over 33,000 compounds; UV/Vis spectra for over 1600 compounds; electronic and vibrational spectra for over 5000 compounds; constants of diatomic molecules(spectroscopic data) for over 600 compounds; ion energetics data for over 16,000 compounds; thermophysical property data for 74 fluids.

  7. Chemistry in microelectronics

    CERN Document Server

    Le Tiec, Yannick

    2013-01-01

    Microelectronics is a complex world where many sciences need to collaborate to create nano-objects: we need expertise in electronics, microelectronics, physics, optics and mechanics also crossing into chemistry, electrochemistry, as well as biology, biochemistry and medicine. Chemistry is involved in many fields from materials, chemicals, gases, liquids or salts, the basics of reactions and equilibrium, to the optimized cleaning of surfaces and selective etching of specific layers. In addition, over recent decades, the size of the transistors has been drastically reduced while the functionalit

  8. Environmental chemistry. 3. ed.

    International Nuclear Information System (INIS)

    The book Environmental Chemistry deals with the basic aspects of environmental chemistry, the natural cycles of the environment, composition of atmosphere and various effects in it by pollutants due to human activities, like energy production, industrial endeavours etc. Details pertaining to the effect of various pollutants on ecosystem are also explained. A number of instrumented techniques in environmental chemical analysis including neutron activation analysis, spectroscopic methods are given. The correlation between energy and environment is dealt with consideration to the global aspects of it. Paper relevant to INIS database is indexed separately. (M.K.V.)

  9. The chemistry of silicon

    CERN Document Server

    Rochow, E G; Emeléus, H J; Nyholm, Ronald

    1975-01-01

    Pergamon Texts in Organic Chemistry, Volume 9: The Chemistry of Silicon presents information essential in understanding the chemical properties of silicon. The book first covers the fundamental aspects of silicon, such as its nuclear, physical, and chemical properties. The text also details the history of silicon, its occurrence and distribution, and applications. Next, the selection enumerates the compounds and complexes of silicon, along with organosilicon compounds. The text will be of great interest to chemists and chemical engineers. Other researchers working on research study involving s

  10. Progress in physical chemistry

    CERN Document Server

    Hempelmann, Rolf

    2008-01-01

    Progress in Physical Chemistry is a collection of recent ""Review Articles"" published in the ""Zeitschrift für Physikalische Chemie"". The second volume of Progress in Physical Chemistry is a collection of thematically closely related minireview articles written by the members of the Collaborative Research Centre (SFB) 277 of the German Research Foundation (DFG). These articles are based on twelve years of intense coordinated research efforts. Central topics are the synthesis and the characterization of interface-dominated, i.e. nanostructured materials, mainly in the solid state but also as

  11. Chemistry in Second Life

    Directory of Open Access Journals (Sweden)

    Bradley Jean-Claude

    2009-10-01

    Full Text Available Abstract This review will focus on the current level on chemistry research, education, and visualization possible within the multi-user virtual environment of Second Life. We discuss how Second Life has been used as a platform for the interactive and collaborative visualization of data from molecules and proteins to spectra and experimental data. We then review how these visualizations can be scripted for immersive educational activities and real-life collaborative research. We also discuss the benefits of the social networking affordances of Second Life for both chemists and chemistry students.

  12. Chemistry and lithography

    CERN Document Server

    Okoroanyanwu, Uzodinma

    2011-01-01

    This is a unique book, combining chemistry and physics with technology and history in a way that is both enlightening and lively. No other book in the field of lithography has as much breadth. Highly recommended for anyone interested in the broad application of chemistry to lithography. --Chris Mack, Gentleman Scientist. This book provides a comprehensive treatment of the chemical phenomena in lithography in a manner that is accessible to a wide readership. The book presents topics on the optical and charged particle physics practiced in lithography, with a broader view of how the marriage bet

  13. Frontiers in nuclear chemistry

    International Nuclear Information System (INIS)

    This book contains articles on the landmarks in nuclear and radiochemistry which takes through scientific history spanning over five decades from the times of Roentgen to the middle of this century. Articles on nuclear fission and back end of the nuclear fuel cycle give an insight into the current status of this subject. Reviews on frontier areas like lanthanides, actinides, muonium chemistry, accelerator based nuclear chemistry, fast radiochemical separations and nuclear medicine bring out the multidisciplinary nature of nuclear sciences. This book also includes an article on environmental radiochemistry and safety. Chapters relevant to INIS are indexed separately

  14. How to teach chemistry? Is Chemistry a new universal language

    OpenAIRE

    López Guerrero, María del Mar; López Guerrero, Gema

    2015-01-01

    Chemistry has been developed greatly throughout the 20th century. Chemistry is included in the curriculum of elementary and secondary education. In general, students are not interested in science, and because of this ,students tend not to make an effort to learn and understand the meaning of concepts and the chemistry language that are being taught to them. If we consider that there is a little bit analogy between chemistry and foreign languages, we should learn the s...

  15. Array processors in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, N.S.

    1980-01-01

    The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

  16. Chromatin chemistry goes cellular.

    OpenAIRE

    W. Fischle; D. Schwarzer; Mootz, H.

    2015-01-01

    Analysing post-translational modifications of histone proteins as they occur within chromatin is challenging due to their large number and chemical diversity. A major step forward has now been achieved by using split intein chemistry to engineer functionalized histones within cells.

  17. Chemistry in Protoplanetary Disks

    OpenAIRE

    Henning, Thomas; Semenov, Dmitry

    2013-01-01

    This comprehensive review summarizes our current understanding of the evolution of gas, solids and molecular ices in protoplanetary disks. Key findings related to disk physics and chemistry, both observationally and theoretically, are highlighted. We discuss which molecular probes are used to derive gas temperature, density, ionization state, kinematics, deuterium fractionation, and study organic matter in protoplanetary disks.

  18. Chemistry Education and Mythology

    OpenAIRE

    Sule Aycan

    2005-01-01

    This study aimed to investigate the effect of mythological story in teaching chemistry. To this end the students in the class were divided into two homogenous groups. While the first group was thought in a traditional way, using a mythological story thought the second group. The story used was based on a Mountain just opposite the faculty.

  19. Chemistry Cook-Off

    Science.gov (United States)

    McCormick, Cynthia

    2012-01-01

    For this activity, high school chemistry students compete in a cooking contest. They must determine the chemical and physical changes that occur in the food they prepare, present their recipe as a step-by-step procedure similar to a lab procedure, identify chemicals in the food, and present all measurements in both metric and English units. The…

  20. Symmetry in chemistry

    CERN Document Server

    Jaffé, Hans H

    1977-01-01

    This book, devoted exclusively to symmetry in chemistry and developed in an essentially nonmathematical way, is a must for students and researchers. Topics include symmetry elements and operations, multiple symmetry operations, multiplication tables and point groups, group theory applications, and crystal symmetry. Extensive appendices provide useful tables.

  1. Nuclear Chemistry, exercises

    International Nuclear Information System (INIS)

    Those exercises have as objective to introduce the student in the basic concepts of nuclear chemistry: a) way of decline b) balances of mass used in nuclear reactions c) how to calculate activities, activity concentrations and specific activity d) radiotracers use in biomedical sciences pharmaceutical

  2. The chemistry of glycerin

    International Nuclear Information System (INIS)

    This book dedicated to chemistry of polyatomic alcohols, in particular, to glycerin and its numerous derivatives. These compounds are very widespread in the natural objects and carry out several functions in alive organism. Big part of these matters are arrange in industry production of base organic synthesis

  3. Online Organic Chemistry

    Science.gov (United States)

    Janowicz, Philip A.

    2010-01-01

    This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…

  4. Nobel Prize in Chemistry

    Science.gov (United States)

    2000-01-01

    The Royal Swedish Academy has awarded the 1999 Nobel Prize in Chemistry to Ahmed H. Zewail (California Institute of Technology, Pasadena, CA) "for his studies of the transition states of chemical reactions using femtosecond spectroscopy". Zewail's work has taken the study of the rates and mechanisms of chemical reactions to the ultimate degree of detail - the time scale of bond making and bond breaking.

  5. Chemistry and Heritage

    Science.gov (United States)

    Vittoria Barbarulo, Maria

    2014-05-01

    Chemistry is the central science, as it touches every aspect of the society we live in and it is intertwined with many aspects of our culture; in particular, the strong link between Chemistry and Archaeology and Art History is being explored, offering a penetrating insight into an area of growing interest from an educational point of view. A series of vital and vibrant examples (i.e., ancient bronzes composition, colour changes due to natural pigment decomposition, marble degradation) has been proposed, on one hand, to improve student understanding of the relationship between cultural and scientific issues arising from the examination, the conservation, and the maintenance of cultural Heritage, on the other, to illustrate the role of the underlying Chemistry. In some case studies, a survey of the most relevant atmospheric factors, which are involved in the deterioration mechanisms, has also been presented to the students. First-hand laboratory experiences have been providing an invaluable means of discovering the full and varied world of Chemistry. Furthermore, the promotion of an interdisciplinary investigation of a famous painting or fresco, involving the study of its nature and significance, the definition of its historical context, any related literature, the chemical knowledge of the materials used, may be an excellent occasion to experiment the Content and Language Integrated Learning (CLIL). The aim of this approach is to convey the important message that everyone has the responsibility to care for and preserve Heritage for the benefit of present and future generations.

  6. Metaphorical Models in Chemistry.

    Science.gov (United States)

    Rosenfeld, Stuart; Bhusan, Nalini

    1995-01-01

    What happens when students of chemistry fail to recognize the metaphorical status of certain models and interpret them literally? Suggests that such failures lead students to form perceptions of phenomena that can be misleading. Argues that the key to making good use of metaphorical models is a recognition of their metaphorical status. Examines…

  7. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  8. The Chemistry of Griseofulvin

    DEFF Research Database (Denmark)

    Petersen, Asger Bjørn; Rønnest, Mads Holger; Larsen, Thomas Ostenfeld;

    2014-01-01

    Specific synthetic routes are presented in schemes to illustrate the chemistry, and the analogs are presented in a table format to give an accessible overview of the structures. Several patents have been published regarding the properties of griseofulvin and its derivatives including synthesis...

  9. Chemistry Education and Mythology

    Directory of Open Access Journals (Sweden)

    Sule Aycan

    2005-01-01

    Full Text Available This study aimed to investigate the effect of mythological story in teaching chemistry. To this end the students in the class were divided into two homogenous groups. While the first group was thought in a traditional way, using a mythological story thought the second group. The story used was based on a Mountain just opposite the faculty.

  10. Forensic Chemistry Training

    Directory of Open Access Journals (Sweden)

    Zuhal GERÇEK

    2012-01-01

    Full Text Available Increasing the types of terrorism and crime nowadays, the importance of the forensic sciences can be bett er understood. Forensic science is the application of the wide spectrum of science to answer the question of legal system. It contains the application of the principles, techniques and methods of basic sciences and its main aim is the determination of the physical facts which are important in legal situations. Forensic chemistry is the branch of chemistry which performs the chemical analysis of evidences that used in the courts. Forensic chemist is the professional chemist who analyzes the evidences from crime scene and reaches a result by application of tests. Th us, they have to have a special education. In forensic laboratories candidates who have chemistry/biochemistry undergraduate degree and took biology and forensic chemistry lectures are preferred. It is necessary to design graduate and undergraduate education to train a forensic chemist. Science education should be at the core of the undergraduate education. In addition to this strong laboratory education on both science and forensic science should be given. Th e graduate program of forensic science example should contain forensic science subjects, strong academic lectures on special subjects and research and laboratory components.

  11. Analytical Chemistry Laboratory

    Science.gov (United States)

    Anderson, Mark

    2013-01-01

    The Analytical Chemistry and Material Development Group maintains a capability in chemical analysis, materials R&D failure analysis and contamination control. The uniquely qualified staff and facility support the needs of flight projects, science instrument development and various technical tasks, as well as Cal Tech.

  12. Evaluating Environmental Chemistry Textbooks.

    Science.gov (United States)

    Hites, Ronald A.

    2001-01-01

    A director of the Indiana University Center for Environmental Science Research reviews textbooks on environmental chemistry. Highlights clear writing, intellectual depth, presence of problem sets covering both the qualitative and quantitative aspects of the material, and full coverage of the topics of concern. Discusses the director's own approach…

  13. Chemistry between the stars

    Science.gov (United States)

    Gammon, R. H.

    1976-01-01

    A unit is presented for the secondary school teacher of physics, chemistry, astronomy, or earth sciences. Included are a list of reference materials, teaching aids, and projects. Discussion questions and a glossary are also provided. Concepts developed are: the nature of interstellar space, spectroscopy, molecular signals from space and interstellar molecules and other areas of astronomy.

  14. Mathematical problems for chemistry students

    CERN Document Server

    Pota, Gyorgy

    2011-01-01

    Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistrystudents in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialistsof the chemistry-related fields (physicists, mathematicians, biologists, etc.) intothe world of the chemical applications.Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, others we

  15. Conference 'Chemistry of hydrides' Proceedings

    International Nuclear Information System (INIS)

    This collection of thesis of conference of Chemistry hydrides presents the results of investigations concerning of base questions of chemistry of nonorganic hydrides, including synthesis questions, studying of physical and chemical properties, thermodynamics, analytical chemistry, investigation of structure, equilibriums in the systems of metal-hydrogen, behaviour of nonorganic hydrides in non-water mediums and applying investigations in the chemistry area and technology of nonorganic hydrides

  16. Predictors of General Chemistry Grades.

    Science.gov (United States)

    Ozsogomonyan, Ardas; Loftus, Drew

    1979-01-01

    Chemistry pretest scores, high school chemistry grades and, to a greater extent, math SAT scores were useful predictors of college general chemistry grades. Regression analysis of all these predictors combined was used to construct an expectancy table which is being used to identify and advise underprepared students. (BB)

  17. Division of Analytical Chemistry, 1998

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    1999-01-01

    The article recounts the 1998 activities of the Division of Analytical Chemistry (DAC- formerly the Working Party on Analytical Chemistry, WPAC), which body is a division of the Federation of European Chemical Societies (FECS). Elo Harald Hansen is the Danish delegate, representing The Danish...... Chemical Society/The Society for Analytical Chemistry....

  18. Combinatorial chemistry and the Grid

    OpenAIRE

    Frey, J G; Bradley, M.; Essex, J.W.; Hursthouse, M. B.; Lewis, S. M.; Luck, M.M.; Moreau, L; De Roure, D C; Surridge, M.; Welsh, A. H.

    2003-01-01

    Chemistry has always made extensive use of the developing computing technology and available computing power though activities such as modelling, simulation and chemical structure interpretational - activities conveniently summarised as computational chemistry. Developing procedures in chemical synthesis and characterisation, particularly in the arena of parallel and combinatorial methodology, have generated ever increasing demands on both Computational Chemistry and Computer Technology. Si...

  19. HMI scientific report - chemistry 1987

    International Nuclear Information System (INIS)

    Results of the R and D activities of the Radiation Chemistry Department, Hahn-Meitner-Institut, are reported, primarily dealing with the following subjects: Interface processes and energy conversion, high-energy photochemistry and radiation chemistry as well as trace elements chemistry. A list of publications and lectures is added and gives a view on results obtained in research and development. (EF)

  20. Annual report 1985 Chemistry Department

    International Nuclear Information System (INIS)

    This annual report describes the activities carried out in 1985 by the Chemistry Department in the following fields: Chemistry, Inorganic Chemistry, Physicochemistry (Interphases, Surfaces), General Chemical Analysis, Active Materials Analysis, X Ray Fluorescence Analysis, Mass Spectroscopy (Isotopic Analysis, Instrumentation) and Optical Spectroscopy. A list of publications is enclosed. (M.E.L.)

  1. Carbohydrates in Supramolecular Chemistry.

    Science.gov (United States)

    Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

    2016-02-24

    Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed. PMID:26702928

  2. Radiation chemistry of oils

    International Nuclear Information System (INIS)

    Full text : Primary investigations have been conducted at the end of the 1950th years in the area of radiation chemistry of the oils, the physical-chemical properties of crude oil have been investigated the influence of ionizing rays. This report by M. Malikzadeh is about the results of investigations carried out in the field of development of radiation chemistry. The power of the radiation dose and temperature-thermal effect of the collapse of Phentadekan -Oil, and oil fractions (200-400 degrees Celsium, 230-310 degrees Celsium) of radiation-thermal separation of olefins - Conversion of hydrogen from the transormation of black oil, bitumen and tar Kinetics of the above-mentioned processes was studied, the technical-economic indicators of the products were determined

  3. Medicinal chemistry for 2020.

    Science.gov (United States)

    Satyanarayanajois, Seetharama D; Hill, Ronald A

    2011-10-01

    Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five main angles to be addressed are: protein-protein interactions; peptides and peptidomimetics; molecular diversity and pharmacological space; molecular pharmacodynamics (significance, potential and challenges); and early-stage clinical efficacy and safety. We then consider, in light of these, the future of medicinal chemistry and the educational preparation that will be required for future medicinal chemists. PMID:22004084

  4. Aqueous chemistry of iodine

    International Nuclear Information System (INIS)

    The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H3BO3 at temperatures up to 1500C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO3- + 2I- + 3H+, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >104 has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs

  5. Chemistry space–time

    Directory of Open Access Journals (Sweden)

    David A. Winkler

    2015-12-01

    Full Text Available As Einstein identified so clearly, space and time are intimately related. We discuss the relationship between time and Euclidean space using spectroscopic and radioastronomical studies of interstellar chemistry as an example. Given the finite speed of light, we are clearly studying chemical reactions occurring tens of thousands of years ago that may elucidate the primordial chemistry of this planet several billion years ago. We also explore space of a different kind – chemical space, with many more dimensions than the four we associate as space–time. Vast chemical spaces also need very efficient (computational methods for their exploration to overcome this ‘curse of dimensionality’. We discuss methods by which the time to explore these new spaces can be very substantially reduced, opening the discovery useful new materials that are the key to our future.

  6. Heterogeneous atmospheric chemistry

    Science.gov (United States)

    Schryer, D. R.

    1982-01-01

    The present conference on heterogeneous atmospheric chemistry considers such topics concerning clusters, particles and microparticles as common problems in nucleation and growth, chemical kinetics, and catalysis, chemical reactions with aerosols, electron beam studies of natural and anthropogenic microparticles, and structural studies employing molecular beam techniques, as well as such gas-solid interaction topics as photoassisted reactions, catalyzed photolysis, and heterogeneous catalysis. Also discussed are sulfur dioxide absorption, oxidation, and oxidation inhibition in falling drops, sulfur dioxide/water equilibria, the evidence for heterogeneous catalysis in the atmosphere, the importance of heterogeneous processes to tropospheric chemistry, soot-catalyzed atmospheric reactions, and the concentrations and mechanisms of formation of sulfate in the atmospheric boundary layer.

  7. Organic Chemistry in Space

    Science.gov (United States)

    Charnley, Steven

    2009-01-01

    Astronomical observations, theoretical modeling, laboratory simulation and analysis of extraterrestrial material have enhanced our knowledge of the inventory of organic matter in the interstellar medium (ISM) and on small bodies such as comets and asteroids (Ehrenfreund & Charnley 2000). Comets, asteroids and their fragments, meteorites and interplanetary dust particles (IDPs), contributed significant amounts of extraterrestrial organic matter to the young Earth. This material degraded and reacted in a terrestrial prebiotic chemistry to form organic structures that may have served as building blocks for life on the early Earth. In this talk I will summarize our current understanding of the organic composition and chemistry of interstellar clouds. Molecules of astrobiological relevance include the building blocks of our genetic material: nucleic acids, composed of subunits such as N-heterocycles (purines and pyrimidines), sugars and amino acids. Signatures indicative of inheritance of pristine and modified interstellar material in comets and meteorites will also be discussed.

  8. Quo vadis, analytical chemistry?

    Science.gov (United States)

    Valcárcel, Miguel

    2016-01-01

    This paper presents an open, personal, fresh approach to the future of Analytical Chemistry in the context of the deep changes Science and Technology are anticipated to experience. Its main aim is to challenge young analytical chemists because the future of our scientific discipline is in their hands. A description of not completely accurate overall conceptions of our discipline, both past and present, to be avoided is followed by a flexible, integral definition of Analytical Chemistry and its cornerstones (viz., aims and objectives, quality trade-offs, the third basic analytical reference, the information hierarchy, social responsibility, independent research, transfer of knowledge and technology, interfaces to other scientific-technical disciplines, and well-oriented education). Obsolete paradigms, and more accurate general and specific that can be expected to provide the framework for our discipline in the coming years are described. Finally, the three possible responses of analytical chemists to the proposed changes in our discipline are discussed. PMID:26631024

  9. Nuclear analytical chemistry

    International Nuclear Information System (INIS)

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection

  10. Supramolecular chemistry and technology

    Directory of Open Access Journals (Sweden)

    HENRIQUE E. TOMA

    2000-03-01

    Full Text Available Supramolecular chemistry deals with the association of several chemical species, in an organized way and according to well defined purposes. Based on a molecular engineering approach, supramolecular structures can be designed from pre-formed building blocks, providing a promising route from chemistry to molecular nanotechnology. New supramolecular systems have been assembled in our laboratory with the use of bridging unities such as tetrapyridylporphyrins, porphyrazines and polypyrazines, connecting transition metal complexes and clusters. These systems display a very exciting electrochemical and catalytic behavior, and interact with DNA, generating ¹O2 and leading to efficient oxidative clivage for photodynamic terapy applications. Molecular interfaces have been developed, exhibiting photocurrent response in the presence of visible-UV light, and rectifying properties in the presence of electroactive species. Successful applications of the supramolecular species in chemical and bio-sensors have been developed.

  11. Muons in chemistry

    Science.gov (United States)

    Clayden, N. J.

    2013-12-01

    Positive muons have long been used as extrinsic probes in chemistry, offering unique properties for the investigation of local magnetism, dynamics, transport and radical kinetics. Exciting new developments in muon beam lines offer the opportunity of extending these studies selectively to surfaces permitting, for example, the detection of increased mobility of polymer chains at the surface of a polymer film. So called pump and probe methods, involving external perturbations by laser irradiation to manipulate vibrational and electronic states, can be followed by muon pulses allowing the probing of the properties of these states. Muoniated radical probes are finding greater use in soft matter. Selectivity is achieved in these complex systems through an appropriate target molecule giving the chance to measure partitioning and interfacial transfer in surfactant systems. Improvements in sample environments allow the observation of muons in increasingly extreme combinations of temperature and pressure, such as supercritical water, allowing the characterization of the chemistry in these systems.

  12. Tropical Soil Chemistry

    DEFF Research Database (Denmark)

    Borggaard, Ole K.

    A new book that is particularly relevant as tropical countries experience increased pressure on land resources to improve agricultural production. To ensure sustainable land use, the potentials and limitations of different kinds of tropical soils must be known in relation to crop production...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...... and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...

  13. Nuclear analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D.; Forkman, B.; Persson, B.

    1984-01-01

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection.

  14. Solvents and sustainable chemistry

    OpenAIRE

    Welton, Tom

    2015-01-01

    Solvents are widely recognized to be of great environmental concern. The reduction of their use is one of the most important aims of green chemistry. In addition to this, the appropriate selection of solvent for a process can greatly improve the sustainability of a chemical production process. There has also been extensive research into the application of so-called green solvents, such as ionic liquids and supercritical fluids. However, most examples of solvent technologies that give improved...

  15. Chemistry of sex attraction.

    OpenAIRE

    Roelofs, W L

    1995-01-01

    The chemical communication system used to attract mates involves not only the overt chemical signals but also indirectly a great deal of chemistry in the emitter and receiver. As an example, in emitting female moths, this includes enzymes (and cofactors, mRNA, genes) of the pheromone biosynthetic pathways, hormones (and genes) involved in controlling pheromone production, receptors and second messengers for the hormones, and host plant cues that control release of the hormone. In receiving ma...

  16. Current ADC Linker Chemistry

    OpenAIRE

    Jain, Nareshkumar; Smith, Sean W.; Ghone, Sanjeevani; Tomczuk, Bruce

    2015-01-01

    The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugati...

  17. Advances in electroanalytical chemistry

    OpenAIRE

    Wang, Yijun; Compton, Richard

    2012-01-01

    This thesis concerns several advances in electroanalytical chemistry which are separated into four parts: the electrochemical investigation of diffusional behaviour, the mechanistic and kinetic study of electrochemistry with room temperature ionic liquids (RTILs), the study of weakly-supported electrochemistry and a comparison of the Butler-Volmer and Marcus-Hush kinetic theories of electron transfer. A study of the diffusional behaviour of electroactive species is essential for further s...

  18. Art and Chemistry

    OpenAIRE

    Walter, Philippe

    2015-01-01

    Philippe Walter’s teaching, which he delivered as holder of the Liliane Bettencourt Annual Chair of Technological Innovation, was completed with two lectures on “practical work” to deal with a real case. The conditions and challenges of interdisciplinary research combining analytical chemistry, art history and archaeology were thus discussed in relation to specific works. The Holy Family, Constantin Abraham (1785-1855) by Raphaël (aka), Sanzio Raffaello (1483-1520), hard porcelain, Sèvres, C...

  19. Chemistry of silybin

    Czech Academy of Sciences Publication Activity Database

    Biedermann, David; Vavříková, Eva; Cvak, L.; Křen, Vladimír

    2014-01-01

    Roč. 31, č. 9 (2014), s. 1138-1157. ISSN 0265-0568 R&D Projects: GA ČR(CZ) GAP301/11/0662; GA MŠk LH13097; GA MŠk(CZ) LD14096; GA MŠk(CZ) LD13042 Institutional support: RVO:61388971 Keywords : silybin * Silybum marianum * separation Subject RIV: CC - Organic Chemistry Impact factor: 10.107, year: 2014

  20. Medicinal chemistry for 2020

    OpenAIRE

    Satyanarayanajois, Seetharama D.; Hill, Ronald A

    2011-01-01

    Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five ma...

  1. Learning Chemistry from Bacteria

    OpenAIRE

    Clardy, Jon

    2013-01-01

    Dr. Jon Clardy Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University All animals, including humans, originated and evolved on a planet already teeming with bacteria, and the two kingdoms of life have been competing and cooperating through their joint history. Although bacteria are most familiar as pathogens, some bacteria produce small molecules that are essential for the biology of animals and other eukaryotes. This lecture explores some of...

  2. Radioanalytical chemistry in Denmark

    International Nuclear Information System (INIS)

    Publications from Denmark in the field of radioanalytical chemistry are presented in 2 groups, one involving neutron activation and similar techniques, and one for other radioanalytical work. Altogether 258 references including books are given for the period 1936-1977, and the overall doubling time is 5.2 years. A significant deviation from a purely exponential growth was caused by the Second World War. (author)

  3. Actinide separative chemistry

    International Nuclear Information System (INIS)

    Actinide separative chemistry has focused very heavy work during the last decades. The main was nuclear spent fuel reprocessing: solvent extraction processes appeared quickly a suitable, an efficient way to recover major actinides (uranium and plutonium), and an extensive research, concerning both process chemistry and chemical engineering technologies, allowed the industrial development in this field. We can observe for about half a century a succession of Purex plants which, if based on the same initial discovery (i.e. the outstanding properties of a molecule, the famous TBP), present huge improvements at each step, for a large part due to an increased mastery of the mechanisms involved. And actinide separation should still focus R and D in the near future: there is a real, an important need for this, even if reprocessing may appear as a mature industry. We can present three main reasons for this. First, actinide recycling appear as a key-issue for future nuclear fuel cycles, both for waste management optimization and for conservation of natural resource; and the need concerns not only major actinide but also so-called minor ones, thus enlarging the scope of the investigation. Second, extraction processes are not well mastered at microscopic scale: there is a real, great lack in fundamental knowledge, useful or even necessary for process optimization (for instance, how to design the best extracting molecule, taken into account the several notifications and constraints, from selectivity to radiolytic resistivity?); and such a need for a real optimization is to be more accurate with the search of always cheaper, cleaner processes. And then, there is room too for exploratory research, on new concepts-perhaps for processing quite new fuels- which could appear attractive and justify further developments to be properly assessed: pyro-processes first, but also others, like chemistry in 'extreme' or 'unusual' conditions (supercritical solvents, sono-chemistry, could be

  4. Quantum mechanics in chemistry

    CERN Document Server

    Schatz, George C

    2002-01-01

    Intended for graduate and advanced undergraduate students, this text explores quantum mechanical techniques from the viewpoint of chemistry and materials science. Dynamics, symmetry, and formalism are emphasized. An initial review of basic concepts from introductory quantum mechanics is followed by chapters examining symmetry, rotations, and angular momentum addition. Chapter 4 introduces the basic formalism of time-dependent quantum mechanics, emphasizing time-dependent perturbation theory and Fermi's golden rule. Chapter 5 sees this formalism applied to the interaction of radiation and matt

  5. Chemistry in Bioinformatics

    OpenAIRE

    Mitchell John; Murray-Rust Peter; Rzepa Henry

    2005-01-01

    Abstract Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the hope of making chemical data (compounds and properties) free during the auth...

  6. Food chemistry. 2. ed.

    International Nuclear Information System (INIS)

    This second edition of the textbook deals with all essential aspects of food chemistry. The revision improved in particular the chapters on food preservation, including irradiation of food, food additives, and pollutants and residues, including radionuclides. The chapter on the German legal regime for foodstuffs has been updated to cover the recent amendments of the law, and the information on processes applied in food technology has been largely enhanced. (VHE) With 153 figs., 78 tabs

  7. Green chemistry: development trajectory

    International Nuclear Information System (INIS)

    Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references

  8. Green chemistry: development trajectory

    Science.gov (United States)

    Moiseev, I. I.

    2013-07-01

    Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references.

  9. Atmospheric pseudohalogen chemistry

    Directory of Open Access Journals (Sweden)

    D. J. Lary

    2004-09-01

    Full Text Available There are at least three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. The first is well known, HCN is a product and marker of biomass burning. However, if a detailed ion chemistry of lightning is considered then it is almost certain than in addition to lightning producing NOx, it also produces HOx and HCN. Unlike NOx and HOx, HCN is long-lived and could therefore be a useful marker of lightning activity. Observational evidence is considered to support this view. Thirdly, the chemical decomposition of HCN leads to the production of small amounts of CN and NCO. NCO can be photolyzed in the visible portion of the spectrum yielding N atoms. The production of N atoms is significant as it leads to the titration of nitrogen from the atmosphere via N+N→N2. Normally the only modelled source of N atoms is NO photolysis which happens largely in the UV Schumann-Runge bands. However, NCO photolysis occurs in the visible and so could be involved in titration of atmospheric nitrogen in the lower stratosphere and troposphere. HCN emission inventories are worthy of attention. The CN and NCO radicals have been termed pseudohalogens since the 1920s. They are strongly bound, univalent, radicals with an extensive and varied chemistry. The products of the atmospheric oxidation of HCN are NO, CO and O3. N+CH4 and N+CH3OH are found to be important sources of HCN. Including the pseudohalogen chemistry gives a small increase in ozone and total reactive nitrogen (NOy.

  10. Chemistry of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Schaedel, M. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan). Advanced Science Research Center; GSI Helmholtz Center for Heavy Ion Research, Darmstadt (Germany)

    2012-07-01

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  11. Chemistry of superheavy elements

    International Nuclear Information System (INIS)

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  12. BWR chromium chemistry

    International Nuclear Information System (INIS)

    This report addresses the concern about higher total specific conductivity in the reactor recirculation loop water due to the chromate ion. This concern is particularly high at plants where all other ionic species have been reduced through careful attention to makeup and condensate polisher operations. An EPRI Chromate Workshop was held in November 1990 to consider the issues raised by observed levels of chromate ion (generally 5 to 50 ppB). While BWRs on normal water chemistry were the only ones observing chromate, even plants on hydrogen water chemistry (HWC) observe sharp spikes of conductivity due to chromate whenever the hydrogen supply was interrupted after a reasonably long HWC operational period. The consensus of the workshop attendees was that chromate was not a concern as an agent causing pipe cracking compared to the more common species such as chloride and sulfate. However, the data are somewhat ambiguous for levels of chromate above 50 ppB. Adjustments to the weighing factors for the various ionic species in the industry chemistry performance index are suggested to allow for the known relative higher aggressiveness of other species relative to that of chromate

  13. General chemistry students' understanding of the chemistry underlying climate science

    Science.gov (United States)

    Versprille, Ashley N.

    The purpose of this study is to investigate first-semester general chemistry students' understanding of the chemistry underlying climate change. The first part of this study involves the collection of qualitative data from twenty-four first-semester general chemistry students from a large Midwestern research institution. The semi-structured interview protocol was developed based on alternative conceptions identified in the research literature and the essential principles of climate change outlined in the U.S. Climate Change Science Program (CCSP) document which pertain to chemistry (CCSP, 2003). The analysis and findings from the interviews indicate conceptual difficulties for students, both with basic climate literacy and underlying chemistry concepts. Students seem to confuse the greenhouse effect, global warming, and the ozone layer, and in terms of chemistry concepts, they lack a particulate level understanding of greenhouse gases and their interaction with electromagnetic radiation, causing them to not fully conceptualize the greenhouse effect and climate change. Based on the findings from these interviews, a Chemistry of Climate Science Diagnostic Instrument (CCSI) was developed for use in courses that teach chemistry with a rich context such as climate science. The CCSI is designed for professors who want to teach general chemistry, while also addressing core climate literacy principles. It will help professors examine their students' prior knowledge and alternative conceptions of the chemistry concepts associated with climate science, which could then inform their teaching and instruction.

  14. Heterogeneous Chemistry in Global Chemistry Transport Models

    Science.gov (United States)

    Stadtler, Scarlet; Simpson, David; Schultz, Martin; Bott, Andreas

    2016-04-01

    The impact of six tropospheric heterogeneous reactions on ozone and nitrogen species was studied using two chemical transport models EMEP MSC-W and ECHAM6-HAMMOZ. Since heterogeneous reactions depend on reactant concentrations (in this study these are N_2O_5, NO_3, NO_2, O_3, HNO_3, HO_2) and aerosol surface area S_a, the modeled surface area of both models was compared to a satellite product retrieving the surface area. This comparison shows a good agreement in global pattern and especially the capability of both models to capture the extreme aerosol loadings in East Asia. Further, the impact of the heterogeneous reactions was evaluated by the simulation of a reference run containing all heterogeneous reactions and several sensitivity runs. One reaction was turned off in each sensitivity run to compare it with the reference run. As previously shown, the analysis of the sensitivity runs shows that the globally most important heterogeneous reaction is the one of N_2O_5. Nevertheless, NO_2, NO_3, HNO3 and HO2 heterogeneous reactions gain relevance particular in East China due to presence of high NOx concentrations and high Sa in the same region. The heterogeneous reaction of O3 itself on dust is compared to the other heterogeneous reactions of minor relevance. Evaluation of the models with northern hemispheric ozone surface observations yields a better agreement of the models with observations when the heterogeneous reactions are incorporated. Impacts of emission changes on the importance of the heterogeneous chemistry will be discussed.

  15. Tropospheric Halogen Chemistry

    Science.gov (United States)

    von Glasow, R.; Crutzen, P. J.

    2003-12-01

    Halogens are very reactive chemicals that are known to play an important role in anthropogenic stratospheric ozone depletion chemistry, first recognized by Molina and Rowland (1974). However, they also affect the chemistry of the troposphere. They are of special interest because they are involved in many reaction cycles that can affect the oxidation power of the atmosphere indirectly by influencing the main oxidants O3 and its photolysis product OH and directly, e.g., by reactions of the Cl radical with hydrocarbons (e.g., CH4).Already by the middle of the nineteenth century, Marchand (1852) reported the presence of bromine and iodine in rain and other natural waters. He also mentions the benefits of iodine in drinking water through the prevention of goitres and cretinism. In a prophetic monograph "Air and Rain: The Beginnings of a Chemical Climatology," Smith (1872) describes measurements of chloride in rain water, which he states to originate partly from the oceans by a process that he compares with the bursting of "soap bubbles" which produces "small vehicles" that transfer small spray droplets of seawater to the air. From deviations of the sulfate-to-chloride ratio in coastal rain compared to seawater, Smith concluded that chemical processes occur once the particles are airborne.For almost a century thereafter, however, atmospheric halogens received little attention. One exception was the work by Cauer (1939), who reported that iodine pollution has been significant in Western and Central Europe due to the inefficient burning of seaweed, causing mean gas phase atmospheric concentrations as high as or greater than 0.5 μg m-3. In his classical textbook Air Chemistry and Radioactivity, Junge (1963) devoted less than three pages to halogen gas phase chemistry, discussing chlorine and iodine. As reviewed by Eriksson (1959a, b), the main atmospheric source of halogens is sea salt, derived from the bursting of bubbles of air which are produced by ocean waves and other

  16. Publicising chemistry in a multicultural society through chemistry outreach

    OpenAIRE

    Joyce D. Sewry; Norman, Nicholas C.; Dudley E. Shallcross; Harrison, Timothy G.; Davies-Coleman, Michael T.

    2011-01-01

    Given the emphasis in Higher Education on community engagement in South Africa and the importance of international collaboration, we discuss a joint approach to chemistry outreach in two countries on two continents with widely differing target school audiences. We describe the history of the partnership between the chemistry departments at Rhodes University and the University of Bristol and provide an outline of the chemistry content of their outreach initiatives, the modes of delivery, the a...

  17. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    OpenAIRE

    Marek Tobiszewski; Mariusz Marć; Agnieszka Gałuszka; Jacek Namieśnik

    2015-01-01

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-establis...

  18. From organic chemistry to fat and oil chemistry*

    OpenAIRE

    Deffense Etienne

    2009-01-01

    With his work on animal fat and identification of fatty acids, Chevreul was a pioneer in organic chemistry. As Chevreul, I had a passion for organic chemistry too. It was then, an honour and a pleasure to present in 2008 at EFL in Athens this presentation entitled “From organic chemistry to fat and oil chemistry” because my background in organic chemistry helped me all along my professional career to understand and implement new developments related to oil and fat technology and processing. A...

  19. Chemistry in Bioinformatics

    Directory of Open Access Journals (Sweden)

    Mitchell John

    2005-06-01

    Full Text Available Abstract Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the hope of making chemical data (compounds and properties free during the authoring process. We argue that the technology is already available; we require a collective agreement to enhance publication protocols.

  20. Optimized random chemistry

    OpenAIRE

    Buzas, Jeffrey S.; Warrington, Gregory S.

    2013-01-01

    The random chemistry algorithm of Kauffman can be used to determine an unknown subset S of a fixed set V. The algorithm proceeds by zeroing in on S through a succession of nested subsets V=V_0,V_1,...,V_m=S. In Kauffman's original algorithm, the size of each V_i is chosen to be half the size of V_{i-1}. In this paper we determine the optimal sequence of sizes so as to minimize the expected run time of the algorithm.

  1. Chemistry of fast electrons

    OpenAIRE

    Maximoff, Sergey N.; Head-Gordon, Martin P.

    2009-01-01

    A chemicurrent is a flux of fast (kinetic energy ≳ 0.5−1.3 eV) metal electrons caused by moderately exothermic (1−3 eV) chemical reactions over high work function (4−6 eV) metal surfaces. In this report, the relation between chemicurrent and surface chemistry is elucidated with a combination of top-down phenomenology and bottom-up atomic-scale modeling. Examination of catalytic CO oxidation, an example which exhibits a chemicurrent, reveals 3 constituents of this relation: The localization of...

  2. Nanoscale surface chemistry

    OpenAIRE

    Madey, Theodore E.; Pelhos, Kalman; WU, QIFEI; Barnes, Robin; Ermanoski, Ivan; Chen, Wenhua; Kolodziej, Jacek J.; Rowe, John E.

    2002-01-01

    We report evidence in several experiments for nanometer-size effects in surface chemistry. The evidence concerns bimetallic systems, monolayer films of Pt or Pd on W(111) surfaces. Pyramidal facets with {211} faces are formed on annealing on physical monolayer of Pt, Pd on a W(111) substrate, and facet sizes increase with annealing temperature. We used synchrotron radiation-based soft x-ray photoemission to show that monolayer films of Pt, Pd, on W “float” on the outer surface, whereas multil...

  3. Radiochemistry and nuclear chemistry

    CERN Document Server

    Choppin, Gregory; RYDBERG, JAN; Ekberg, Christian

    2013-01-01

    Radiochemistry or nuclear chemistry is the study of radiation from an atomic and molecular perspective, including elemental transformation and reaction effects, as well as physical, health and medical properties. This revised edition of one of the earliest and best-known books on the subject has been updated to bring into teaching the latest developments in research and the current hot topics in the field. To further enhance the functionality of this text, the authors have added numerous teaching aids, examples in MathCAD with variable quantities and options, hotlinks to relevant text secti

  4. Principles of quantum chemistry

    CERN Document Server

    George, David V

    2013-01-01

    Principles of Quantum Chemistry focuses on the application of quantum mechanics in physical models and experiments of chemical systems.This book describes chemical bonding and its two specific problems - bonding in complexes and in conjugated organic molecules. The very basic theory of spectroscopy is also considered. Other topics include the early development of quantum theory; particle-in-a-box; general formulation of the theory of quantum mechanics; and treatment of angular momentum in quantum mechanics. The examples of solutions of Schroedinger equations; approximation methods in quantum c

  5. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  6. Arene ruthenium chemistry

    OpenAIRE

    Bates, Richard Simon

    1990-01-01

    This thesis describes the synthesis and reactivity studies of new arene-ruthenium(II) and arene-ruthenium(O) complexes. Ultrasound has been investigated as an alternative energy source, with the overall aim of synthesising arene ruthenium clusters. Chapter 1 gives an introduction and summary of the known arene ruthenium chemistry reported to date. Chapter 2 reports the synthesis of (CGH6)Ru(C2H4)2 and (MeC6H4CHMe2)Ru(C2H4)2. Low temperature protonation studies generated (C6H6)Ru(H)(CZH4...

  7. Introduction to supramolecular chemistry

    CERN Document Server

    Dodziuk, Helena

    2007-01-01

    'A major strength of this work is its inclusion of literally hundreds of clearly drawn structures and diagrams to assist reader understanding of this complex area. In addition, the author has included hundreds of up-to-date references. It also has a useful and extensive index. The book is valuable not only to those working in the field of supramolecular chemistry, but also to chemists in unrelated areas of research who want a refreshingly well-written monograph on an emerging area of important research.' H.T. McKone, Saint Joseph College in Choice, September 2002

  8. Radiochemistry and actinide chemistry

    International Nuclear Information System (INIS)

    The analysis of trace amounts of actinide elements by means of radiochemistry, is discussed. The similarities between radiochemistry and actinide chemistry, in the case of species amount by cubic cm below 1012, are explained. The parameters which allow to define what are the observable chemical reactions, are given. The classification of radionuclides in micro or macrocomponents is considered. The validity of the mass action law and the partition function in the definition of the average number of species for trace amounts, is investigated. Examples illustrating the results are given

  9. Analytical chemistry in space

    CERN Document Server

    Wainerdi, Richard E

    1970-01-01

    Analytical Chemistry in Space presents an analysis of the chemical constitution of space, particularly the particles in the solar wind, of the planetary atmospheres, and the surfaces of the moon and planets. Topics range from space engineering considerations to solar system atmospheres and recovered extraterrestrial materials. Mass spectroscopy in space exploration is also discussed, along with lunar and planetary surface analysis using neutron inelastic scattering. This book is comprised of seven chapters and opens with a discussion on the possibilities for exploration of the solar system by

  10. Introduction to Coordination Chemistry

    CERN Document Server

    Lawrance, Geoffrey Alan

    2010-01-01

    Introduction to Coordination Chemistry examines and explains how metals and molecules that bind as ligands interact, and the consequences of this assembly process. This book describes the chemical and physical properties and behavior of the complex assemblies that form, and applications that may arise as a result of these properties. Coordination complexes are an important but often hidden part of our world?even part of us?and what they do is probed in this book. This book distills the essence of this topic for undergraduate students and for research scientists.

  11. Chemistry in space

    CERN Document Server

    Rehder, Dieter

    2010-01-01

    The dynamic field of extraterrestrial chemistry brings together ideas of chemistr, astrophysics, and biology to the study of molecules between stars, around stars, and on plantes. This book serves as an introduction to chemial processes under ?unearthly? and hence usually extreme conditions (temperature, pressure, high or low density, bombardment by cosmic rays), and their impact on the early development of our solar system, as well as providing a deeper understanding of processes in earthly regions where conditions approach those of extraterrestrial areas.A unique and extraordinary perspe

  12. Radiation chemistry in microemulsion

    International Nuclear Information System (INIS)

    Radiation chemistry can be used to study reactions of free radicals not only in homogeneous medium but also in micro-heterogeneous medium, microemulsion being typical example of this type of medium. This article intends to summarize some radiation chemical studies in microemulsion using pulse radiolysis as a tool. Attempt has been made to show that the reaction and self-decay of hydrated electron can lead to achieve useful results relating to the physical properties of micro-droplets. Moreover, free radical reactions with biomolecules in these media can sometime be extrapolated to living systems. (author)

  13. Quantum chemistry an introduction

    CERN Document Server

    Kauzmann, Walter

    2013-01-01

    Quantum Chemistry: An Introduction provides information pertinent to the fundamental aspects of quantum mechanics. This book presents the theory of partial differentiation equations by using the classical theory of vibrations as a means of developing physical insight into this essential branch of mathematics.Organized into five parts encompassing 16 chapters, this book begins with an overview of how quantum mechanical deductions are made. This text then describes the achievements and limitations of the application of quantum mechanics to chemical problems. Other chapters provide a brief survey

  14. From China to the world: Science China Chemistry celebrates the International Year of Chemistry

    Institute of Scientific and Technical Information of China (English)

    ZHU XiaoWen; XUE Zi-Ling

    2012-01-01

    1 Introduction Science China Chemistry is considered the best and most comprehensive chemistry journal in China,Its primary mission is to communicate the results of basic and innovative chemistry research.The subject areas include physical chemistry,organic chemistry,inorganic chemistry,polymer chemistry,biological chemistry,environmental chemistry,and chemical engineering in the form of Feature Articles,Reviews,Communications,Articles,and News & Comments.

  15. MICROSCALE CHEMISTRY IN LATIN AMERICA

    Directory of Open Access Journals (Sweden)

    Jorge G. Ibáñez

    2005-06-01

    Full Text Available A brief account of the development of Microscale Chemistry in Latin America is here presented. The US National Microscale Chemistry Center (Merrimack College, Massachusetts was instrumental in the initiationof several centers. Its Mexican counterpart, the Mexican Microscale Chemistry Center (CMQM, has been a key player in this process. Other participating countries include Argentina, Bolivia, Brazil, Chile, Cuba,Guatemala, Perú and Uruguay.

  16. Six Phases of Cosmic Chemistry

    OpenAIRE

    Lukasz Lamza

    2014-01-01

    The article presents a conceptually unified, quantitative account of the development of chemical phenomena throughout the cosmic history, with a detailed discussion of the cosmological, astrophysical, geological, biological, and anthropological context. The totality of cosmic chemistry is represented by a list of 176 classes of phenomena, drawn from the Universal Decimal Classification (UDC) library cataloguing system, and divided into 6 phases: of no chemistry, of prestellar chemistry, of ga...

  17. NUCLEAR CHEMISTRY ANNUAL REPORT 1970

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1971-05-01

    Papers are presented for the following topics: (1) Nuclear Structure and Nuclear Properties - (a) Nuclear Spectroscopy and Radioactivity; (b) Nuclear Reactions and Scattering; (c) Nuclear Theory; and (d) Fission. (2) Chemical and Atomic Physics - (a) Atomic and Molecular Spectroscopy; and (b) Hyperfine Interactions. (3) Physical, Inorganic, and Analytical Chemistry - (a) X-Ray Crystallography; (b) Physical and Inorganic Chemistry; (c) Radiation Chemistry; and (d) Chemical Engineering. (4) Instrumentation and Systems Development.

  18. Sixty Years of Chemistry at CAS

    Institute of Scientific and Technical Information of China (English)

    WAN Li-Jun

    2011-01-01

    @@ As one of the fundamental and key disciplines of natural sciences, chemistry deals with the properties, composition, structure, transformation and applications of substances.It could be further divided into several branches, such as inorganic chemistry, organic chemistry, physical chemistry, polymer chemistry, analytical chemistry and chemical engineering.In recent years, many new branches and fields have emerged amide the continuous development of chemistry and its interdisciplinary research with mathematics, physics, astronomy, earth science, biology, medical science, materials science, and environmental science.

  19. Complex Protostellar Chemistry

    Science.gov (United States)

    Nuth, Joseph A., III; Johnson, Natasha M.

    2012-01-01

    Two decades ago, our understanding of the chemistry in protostars was simple-matter either fell into the central star or was trapped in planetary-scale objects. Some minor chemical changes might occur as the dust and gas fell inward, but such effects were overwhelmed by the much larger scale processes that occurred even in bodies as small as asteroids. The chemistry that did occur in the nebula was relatively easy to model because the fall from the cold molecular cloud into the growing star was a one-way trip down a well-known temperature-pressure gradient; the only free variable was time. However, just over 10 years ago it was suggested that some material could be processed in the inner nebula, flow outward, and become incorporated into comets (1, 2). This outward flow was confirmed when the Stardust mission returned crystalline mineral fragments (3) from Comet Wild 2 that must have been processed close to the Sun before they were incorporated into the comet. In this week's Science Express, Ciesla and Sandford (4) demonstrate that even the outermost regions of the solar nebula can be a chemically active environment. Their finding could have consequences for the rest of the nebula.

  20. Materials Chemistry Studies

    International Nuclear Information System (INIS)

    In 2006, a new research group has been created at the SCK-CEN in order to focus more specifically on chemical issues relevant to the studies of materials. The integrated staff personnel has a long experience in many different fields of expertise such as radiochemistry (fuel cycles and radioisotopes), organic chemistry, electrochemistry (analytical techniques and corrosion) and sonochemistry. The previously running activities are now being reoriented according to a well-defined work programme. Each research line that was previously running had specific objectives. Fuel cycle studies were axed on the partitioning of lanthanides and actinides in aqueous solutions. Support to corrosion studies was devoted to the development of a new method for the treatment of electrochemical noise data for the detection and the classification of local corrosion events. New objectives for the future put a strong accent on radioisotopes for the pharmaceutical industry as well as the use of non-aqueous chemistry as a tool for several applications among which the treatment and the separation of radioisotopes, analytical measurements as well as the chemical control of impurities in liquid metals

  1. Solid state chemistry an introduction

    CERN Document Server

    Smart, Lesley E

    2012-01-01

    ""Smart and Moore are engaging writers, providing clear explanations for concepts in solid-state chemistry from the atomic/molecular perspective. The fourth edition is a welcome addition to my bookshelves. … What I like most about Solid State Chemistry is that it gives simple clear descriptions for a large number of interesting materials and correspondingly clear explanations of their applications. Solid State Chemistry could be used for a solid state textbook at the third or fourth year undergraduate level, especially for chemistry programs. It is also a useful resource for beginning graduate

  2. Graduate Education in Environmental Chemistry

    Science.gov (United States)

    Lee, G. Fred

    1974-01-01

    Describes the role chemistry departments should assume in the environmental quality control area. Includes problems of program design, course offerings, research problems, and career qualifications. (GS)

  3. A green chemistry lab course

    International Nuclear Information System (INIS)

    The traditional course content of chemistry classes must change to achieve better awareness of the important issues of sustainability in chemistry within the next generation of professional chemists. To provide the necessary material for the organic chemistry teaching lab course, which is part of almost all study programs in chemistry, material was developed and collected (http://www.oc-praktikum.de/en) that allows students and teachers to assess reactions beyond the experimental set up, reaction mechanism and chemical yield. Additional parameters like atom economy of chemical transformations, energy efficiency, and questions of waste, renewable feed stocks, toxicity and ecotoxicity, as well as the safety measures for the chemicals used are discussed. (author)

  4. Cross-Connections of Chemistry

    Science.gov (United States)

    Mason, Diana S.

    2002-02-01

    We are in desperate need of qualified chemistry teachers. Are the teachers who have biology, physics, or some psychology degrees qualified to teach chemistry? Have they taken enough chemistry to be prepared to teach outside their degree field? If remediation is necessary, what courses should be required? Attracting pre-service science teachers to the study of pure chemistry is not an easy task when more attractive course offerings are available. Maybe we should concentrate on cross-training in-service teachers by providing appropriate graduate courses to encourage them and bring them into the family. Many teachers with degrees outside the traditional discipline of chemistry have adequate backgrounds in the applications of chemistry. Requiring hours of undergraduate education before they enter the hallowed halls of the chemistry building as graduate students only serves to discourage a large segment of in-service teachers who wish to broaden their perspective. The National Science Education Standards make a compelling argument for connecting and integrating science courses for practicing teachers (3). We are at the crossroads. At a time when we so desperately need qualified chemistry teachers, shouldn't we be more open in our graduate teaching programs, inviting those with degrees in other disciplines to start on a graduate degree without insisting on undergraduate or survey coursework first? Many potential chemical education graduate students have a background in chemistry--it is just known by another name.

  5. Influencing College Chemistry Success through High School Chemistry Teaching

    Science.gov (United States)

    Tai, Robert H.; Sadler, Philip M.; Loehr, John F.

    2006-01-01

    The connection between high school chemistry pedagogical experiences and introductory college chemistry performance has been a topic researched in published science education literature since the 1920s. However, analysis techniques have limited the generalizability of these results. This review discusses the findings of a large-scale,…

  6. Introducing Chemistry Students to the "Real World" of Chemistry

    Science.gov (United States)

    Brown, Michael E.; Cosser, Ronald C.; Davies-Coleman, Michael T.; Kaye, Perry T.; Klein, Rosalyn; Lamprecht, Emmanuel; Lobb, Kevin; Nyokong, Tebello; Sewry, Joyce D.; Tshentu, Zenixole R.; van der Zeyde, Tino; Watkins, Gareth M.

    2010-01-01

    A majority of chemistry graduates seek employment in a rapidly changing chemical industry. Our attempts to provide the graduates with skills in entrepreneurship and the ability to understand and communicate with their chemical engineering colleagues, in addition to their fundamental knowledge of chemistry, are described. This is done at…

  7. A Quantum Chemistry Concept Inventory for Physical Chemistry Classes

    Science.gov (United States)

    Dick-Perez, Marilu; Luxford, Cynthia J.; Windus, Theresa L.; Holme, Thomas

    2016-01-01

    A 14-item, multiple-choice diagnostic assessment tool, the quantum chemistry concept inventory or QCCI, is presented. Items were developed based on published student misconceptions and content coverage and then piloted and used in advanced physical chemistry undergraduate courses. In addition to the instrument itself, data from both a pretest,…

  8. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    Directory of Open Access Journals (Sweden)

    Marek Tobiszewski

    2015-06-01

    Full Text Available The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed.

  9. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry.

    Science.gov (United States)

    Tobiszewski, Marek; Marć, Mariusz; Gałuszka, Agnieszka; Namieśnik, Jacek

    2015-01-01

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed. PMID:26076112

  10. Clays in prebiological chemistry

    Science.gov (United States)

    Rao, M.; Oro, J.; Odom, D. G.

    1980-01-01

    The ways in which clays have been utilized in studies of prebiological chemistry are reviewed, and an assessment is given of the possible role of clays in prebiological systems. The adsorption of organic molecules on clays has been demonstrated, as has the synthesis of bioorganic monomers in the presence of clays. For instance, amino acids, purines and pyrimidines have been obtained from carbon monoxide and nitric acid in the presence of clays at relatively high temperatures (250-325 C). The oligomerization of biochemical monomers, mediated by clays, has also been shown to result in the formation of polymer molecules basic to life. Clays have also been found to affect the condensation of mononucleotides to oligonucleotides.

  11. Organic chemistry on Titan

    Science.gov (United States)

    Chang, S.; Scattergood, T.; Aronowitz, S.; Flores, J.

    1979-01-01

    Features taken from various models of Titan's atmosphere are combined in a working composite model that provides environmental constraints within which different pathways for organic chemical synthesis are determined. Experimental results and theoretical modeling suggest that the organic chemistry of the satellite is dominated by two processes: photochemistry and energetic particle bombardment. Photochemical reactions of CH4 in the upper atmosphere can account for the presence of C2 hydrocarbons. Reactions initiated at various levels of the atmosphere by cosmic rays, Saturn 'wind', and solar wind particle bombardment of a CH4-N2 atmospheric mixture can account for the UV-visible absorbing stratospheric haze, the reddish appearance of the satellite, and some of the C2 hydrocarbons. In the lower atmosphere photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. It is concluded that the surface of Titan may contain ancient or recent organic matter (or both) produced in the atmosphere.

  12. Advances in analytical chemistry

    Science.gov (United States)

    Arendale, W. F.; Congo, Richard T.; Nielsen, Bruce J.

    1991-01-01

    Implementation of computer programs based on multivariate statistical algorithms makes possible obtaining reliable information from long data vectors that contain large amounts of extraneous information, for example, noise and/or analytes that we do not wish to control. Three examples are described. Each of these applications requires the use of techniques characteristic of modern analytical chemistry. The first example, using a quantitative or analytical model, describes the determination of the acid dissociation constant for 2,2'-pyridyl thiophene using archived data. The second example describes an investigation to determine the active biocidal species of iodine in aqueous solutions. The third example is taken from a research program directed toward advanced fiber-optic chemical sensors. The second and third examples require heuristic or empirical models.

  13. Prebiotic chemistry in clouds

    Science.gov (United States)

    Oberbeck, Verne R.; Marshall, John; Shen, Thomas

    1991-01-01

    The chemical evolution hypothesis of Woese (1979), according to which prebiotic reactions occurred rapidly in droplets in giant atmospheric reflux columns was criticized by Scherer (1985). This paper proposes a mechanism for prebiotic chemistry in clouds that answers Scherer's concerns and supports Woese's hypothesis. According to this mechanism, rapid prebiotic chemical evolution was facilitated on the primordial earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by, or synthesized during entry of meteorites, comets, and interplanetary dust, would have been scavenged by cloud drops containing clay condensation nuclei and would be polymerized within cloud systems during cycles of condensation, freezing, melting, and evaporation of cloud drops.

  14. Prebiotic phosphorus chemistry reconsidered

    Science.gov (United States)

    Schwartz, A. W.; Orgel, L. E. (Principal Investigator)

    1997-01-01

    The available evidence indicates that the origin of life on Earth certainly occurred earlier than 3.5 billion years ago and perhaps substantially earlier. The time available for the chemical evolution which must have preceded this event is more difficult to estimate. Both endogenic and exogenic contributions to chemical evolution have been considered; i.e., from chemical reactions in a primitive atmosphere, or by introduction in the interiors of comets and/or meteorites. It is argued, however, that the phosphorus chemistry of Earth's earliest hydrosphere, whether primarily exogenic or endogenic in origin, was most likely dominated by compounds less oxidized than phosphoric acid and its esters. A scenario is presented for the early production of a suite of reactive phosphonic acid derivatives, the properties of which may have foreshadowed the later appearance of biophosphates.

  15. Rapid automated nuclear chemistry

    International Nuclear Information System (INIS)

    Rapid Automated Nuclear Chemistry (RANC) can be thought of as the Z-separation of Neutron-rich Isotopes by Automated Methods. The range of RANC studies of fission and its products is large. In a sense, the studies can be categorized into various energy ranges from the highest where the fission process and particle emission are considered, to low energies where nuclear dynamics are being explored. This paper presents a table which gives examples of current research using RANC on fission and fission products. The remainder of this text is divided into three parts. The first contains a discussion of the chemical methods available for the fission product elements, the second describes the major techniques, and in the last section, examples of recent results are discussed as illustrations of the use of RANC

  16. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    During the past year the Nuclear Chemistry Group at Indiana University has concentrated its efforts on (1) the analysis and publication of previous experimental studies and (2) the design and construction of ISiS, a 4π detector for multifragment emission studies. No new experiments were undertaken, rather all of our experimental effort has been directed toward component tests of ISiS, with a goal of beginning measurements with this device in 1992. Research projects that have been largely completed during the last year include: (1) multiple fragment emission studies of the 0.90 and 3.6 GeV 3He + natAg reaction; (2) intermediate-mass-fragment (IMF: 3 ≤ Z ≤ 15) excitation function measurements for the E/A = 20-to-100 MeV 14N + natAg and 197Au reactions, and (3) particle-particle correlation studies for the determination of space-time relationships energy collisions

  17. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  18. Environmental chemistry of technetium

    International Nuclear Information System (INIS)

    Safe disposal of waste is perceived by public opinion as probably the greatest technical problem of the nuclear industry. This concern derives from the large quantities of radioactivity involved and from the suspicion that man-made barriers are not completely reliable for the lifetime of such waste. Therefore, the biogeochemical cycling of long-lived radionuclides resulting from nuclear power generation represents an important factor influencing decisions regarding the future development of the nuclear industry. As far as technetium is concerned, it should be mentioned that the hazard from the isotope /sup 99/Tc remains practically unchanged for some 30,000 years because of its 2.1x10/sup 5/ year half-life. In this paper the information available on the environmental chemistry of technetium is discussed in order to evaluate the importance of chemical processes in determining the distribution of technetium in the biosphere

  19. Rapid automated nuclear chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, R.A.

    1979-05-31

    Rapid Automated Nuclear Chemistry (RANC) can be thought of as the Z-separation of Neutron-rich Isotopes by Automated Methods. The range of RANC studies of fission and its products is large. In a sense, the studies can be categorized into various energy ranges from the highest where the fission process and particle emission are considered, to low energies where nuclear dynamics are being explored. This paper presents a table which gives examples of current research using RANC on fission and fission products. The remainder of this text is divided into three parts. The first contains a discussion of the chemical methods available for the fission product elements, the second describes the major techniques, and in the last section, examples of recent results are discussed as illustrations of the use of RANC.

  20. Modelling electric discharge chemistry

    International Nuclear Information System (INIS)

    The chemistry occurring in a electric discharge was modelled to predict how it would be influenced by discharge conditions. The discharge was characterized by a calculated Boltzmann electron-energy distribution, from which rate constants for electron-molecule processes in air were determined. These rate constants were used in a chemical kinetics calculation that also included reactions between neutral molecules, ions, free radicals and electronically excited species. The model describes how the discharge chemistry was influenced by humidity, electric field, electron number density, and concentrations of key reagents identified in the study. The use of an electric discharge to destroy airborne contaminant molecules was appraised, the targeted contaminants being CF2Cl2, HCN, and SO2. The modelling results indicate that an electric discharge should be able to remove HCN and CF2Cl2 effectively, especially if the discharge conditions have been optimized. Effective destruction is achieved with a moderate electric field (over 1 x 10-15 V.cm2), a substantial electron number density (over 1 x 1012 cm-3), and the presence of H20 in the process air. The residence time in the discharge was also shown to be important in contaminant destruction. An attempt was made to explain the results of the electric discharge abatement of SO2, a component of a simulated flue-gas mixture. Results from the model indicate that the discharge parameters that increase the concentration of hydroxyl radical also increase the rate of decomposition of SO2. An objective of the study was to explain the apparent enhancement of SO2 destruction by the presence of a small amount of NO2. It was thought that a likely explanation would be the stabilization of HOSO2, an important intermediate in the oxidation of SO2 by NO2. (49 figs., 14 tabs., 75 refs.)

  1. Nanoplasmonics tuned ``click chemistry''

    Science.gov (United States)

    Tijunelyte, I.; Guenin, E.; Lidgi-Guigui, N.; Colas, F.; Ibrahim, J.; Toury, T.; Lamy de La Chapelle, M.

    2016-03-01

    Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised ``click'' reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the ``click'' chemistry.Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised ``click'' reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the ``click'' chemistry. Electronic supplementary information (ESI) available: NMR study on reaction initiation, SERS spectra and temperature calculations. See DOI: 10.1039/c5nr09018k

  2. Local Evaluation of Chemistry Journals

    Science.gov (United States)

    Kraus, Joseph R.; Hansen, Rachel

    2008-01-01

    This paper reports on the evaluation of local usage statistics of a specific set of chemistry journals at the University of Denver in Colorado, USA. The objective of the study is to demonstrate that commercial publishers in chemistry charge considerably more for their journals than those from the non-commercial sector. There are three variables…

  3. HMI scientific report - chemistry 1988

    International Nuclear Information System (INIS)

    Results of the R and D activities are reported, dealing with the following subjects: Interface processes and energy conversion, high-energy photochemistry and radiation chemistry as well as trace elements chemistry. A list of publications and lectures is added and gives a view on results obtained in research and development. (EF)

  4. Chemistry Teachers' Views of Creativity

    Science.gov (United States)

    Akkanat, Çigdem; Gökdere, Murat

    2015-01-01

    The purpose of this study was to determine chemistry teachers' views of creativity. In this study, phenomenology method, one of the qualitative research patterns, was used. The participants of this study were 13 chemistry teachers working in Amasya. A semi-structured interview form was used for data collection. By using NVivo 9 qualitative…

  5. News from Online: Green Chemistry

    Science.gov (United States)

    Uffelman, Erich S.

    2004-01-01

    Green chemistry closely relates to energy and environmental problems, and includes the promotion of environmental friendly products and systems within the framework of renewable resources. Various websites on green chemistry are reviewed, one of which lists the 12 commandments of this particular subject.

  6. Introducing Relativity into Quantum Chemistry

    Science.gov (United States)

    Li, Wai-Kee; Blinder, S. M.

    2011-01-01

    It is not often realized by chemists that the special theory of relativity is behind several aspects of quantum chemistry. The Schrdinger equation itself is based on relations between space-time and energy-momentum four vectors. Electron spin is, of course, the most obvious manifestation of relativity. The chemistry of some heavy elements is…

  7. A Cooperative Chemistry Project: Chemsource.

    Science.gov (United States)

    Giles, Catherine Y.

    1994-01-01

    Chemsource is a set of instructional materials designed as a resource for high school chemistry teachers, particularly those not trained in the discipline. Materials consist of a videotape demonstrating both generic and science-specific teaching skills and a textbook on varied chemistry topics, including suggested teaching techniques and…

  8. Contextualising Nanotechnology in Chemistry Education

    Science.gov (United States)

    O'Connor, Christine; Hayden, Hugh

    2008-01-01

    In recent years nanotechnology has become part of the content of many undergraduate chemistry and physics degree courses. This paper deals with the role of contextualisation of nanotechnology in the delivery of the content, as nanotechnology is only now being slowly integrated into many chemistry degree courses in Ireland and elsewhere. An…

  9. Crocodile Chemistry. [CD-ROM].

    Science.gov (United States)

    1999

    This high school chemistry resource is an on-screen chemistry lab. In the program, students can experiment with a huge range of chemicals, choosing the form, quantity and concentrations. Dangerous or difficult experiments can be investigated safely and easily. A vast range of equipment can be set up, and complex simulations can be put together and…

  10. Comet Halley and interstellar chemistry

    International Nuclear Information System (INIS)

    How complex is the chemistry of the interstellar medium? How far does it evolve and how has it interacted with the chemistry of the solar system? Are the galactic chemical processes destroyed, preserved, or even enhanced in comets? Are biogenic molecules formed in space and have the formation mechanisms interacted in any way with prebiotic organic chemical processes on the early earth? Radio molecular studies of comets are important for probing deep into the coma and nuclear region and thus may help answer these questions. Comets are believed to be pristine samples of the debris left from the formation of the solar system and may have been the carrier between interstellar and terrestrial prebiotic chemistries. Recent observations of Comet Halley and subsequent comets have given the author an excellent opportunity to study the relationship between interstellar molecular chemistry and cometary chemistry

  11. Proceedings of the 17. Annual Meeting of the Brazilian Chemistry Society; 7. National Symposium on Inorganic Chemistry. Abstracts

    International Nuclear Information System (INIS)

    These 17. Annual Meeting of the Brazilian Chemistry Society and 7. National Symposium on Inorganic Chemistry present several subjects of different interests for the participants, including sections about inorganic chemistry; organic chemistry; environmental chemistry; technological chemistry; electrochemistry; physical chemistry; photochemistry; chemical education; natural products; analytical chemistry and biological chemistry. (C.G.C.)

  12. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

    Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

  13. Bentonite porewater chemistry

    International Nuclear Information System (INIS)

    Porewater composition in a compacted bentonite is dependent on the composition of the surrounding groundwater, and on the characteristics of the bentonite itself. Two mechanisms through which bentonite influences the respective porewater composition are distinguished: surface chemical reactions (ion exchange, surface complexation) on smectite and dissolution of minerals and soluble impurities included in bentonite. This report provides the results of different activities related to the definition of porewater chemistry through the use of geochemical models: 1) review of thermodynamic model on ion exchange reaction, 2) modeling of bentonite-water interactions under aerobic conditions, 3) performance of sensitivity analyses of key parameters in the bentonite model, 4) model simulation of bentonite porewater chemistry in the engineered barrier system under repository conditions. Experimental information of bentonite-water interaction allowed the determination of soluble impurities in the bentonite, and the knowledge of these impurities is important for predictive modeling. For the impurities of Kunigel-V1, 0.38% of CaSO4, 0.0011% of NaCl and 0.0044% of KCl were determined. The sensitivity analyses resulted in that the presence of calcite, CaSO4 and pyrite strongly influences the pH in the compacted bentonite, and the pH in compacted bentonite is buffered by the acid/base equilibria at the Na-smectite surface as well. Through the model calculations, some remarks on the expected trends for the long term behavior can be made like that the pH in compacted bentonite is expected to increase with increasing number of water exchange cycles, as long as CaCO3 contributes to the pH buffering capacity, due to slow depletion of the soluble impurities in the bentonite. The pH of the porewater, however, lies in all cases (but in the presence of CaCo3) between 5.6 and 9.5. Based on the findings discussed above, a large number of calculations were carried out to support the definition

  14. Chemistry of Technetium

    International Nuclear Information System (INIS)

    Precise and reliable thermodynamic constants for the oxidation/reduction relationships of the technetium ions in various environments are necessary to model the transport behaviour of 99 Tc from the nuclear waste repositories to the bio and geosphere. The current knowledge of the Tc chemistry indicates that the most important oxidation states of Tc in natural environment would be VII in oxidant conditions and IV, in an-oxidant media. However, even the value of the formal oxidation potential of the Tc O4-/Tc (IV) couple in simple media is questionable, because it relies only upon one kind of data: the values of the potential of the half electrochemical cell Tc O4-/Tc O2. These potentials are reversible, but sparingly soluble Tc O2 is not in fast equilibrium with other Tc (IV) complexes. The measured potentials are surely Tc O4-/Tc O2 potentials, but not the Tc O4-/Tc(IV) potentials if Tc O2 is not the thermodynamically stable form of Tc (IV). Quantitative data for the Tc O2 equilibria with Tc (IV) complexes are difficult to obtain because of the slowness of the ligand exchange reactions and the general lack of knowledge of the chemistry of the VIIb group tetravalent ions. The present investigation deals with a new approach for the determination of the formal oxidation potential of the Tc O4-/Tc (IV) couple. Tc was used at trace level, in order to avoid the kinetic and thermodynamic sinks made by insoluble Tc O2. Oxidation and reduction of Tc were governed by controlling the ion concentration of a fast electron exchanger couple of which the formal potential has been measured carefully, presently Fe (III)/Fe (II). Distribution ratios of Tc between aqueous and immiscible organic solution of tetra-phenyl arsenic chloride (TPA.Cl) into chloroform served as the probe for the advancement of oxidation and reduction reaction. In these solvent, only Tc (VII) as Tc O4- anions is extracted. (authors)

  15. COST : action chemistry conference on supramolecular chemistry in water

    OpenAIRE

    Magri, David C.

    2014-01-01

    Scientists and chemists from 18 countries gathered in Malta for the 3rd Scientific Meeting on Supramolecular Chemistry in Water between the 9 − 11th of November 2013 at the Old University Building on St Paul Street in Valletta

  16. Incorporation of Medicinal Chemistry into the Organic Chemistry Curriculum

    Science.gov (United States)

    Forbes, David C.

    2004-01-01

    Application of concepts presented in organic chemistry lecture using a virtual project involving the sythesis of medicinally important compounds is emphasized. The importance of reinforcing the concepts from lecture in lab, thus providing a powerful instructional means is discussed.

  17. Advanced Chemistry Basins Model

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, Mario; Cathles, Lawrence; Manhardt, Paul; Meulbroek, Peter; Tang, Yongchun

    2003-02-13

    The objective of this project is to: (1) Develop a database of additional and better maturity indicators for paleo-heat flow calibration; (2) Develop maturation models capable of predicting the chemical composition of hydrocarbons produced by a specific kerogen as a function of maturity, heating rate, etc.; assemble a compositional kinetic database of representative kerogens; (3) Develop a 4 phase equation of state-flash model that can define the physical properties (viscosity, density, etc.) of the products of kerogen maturation, and phase transitions that occur along secondary migration pathways; (4) Build a conventional basin model and incorporate new maturity indicators and data bases in a user-friendly way; (5) Develop an algorithm which combines the volume change and viscosities of the compositional maturation model to predict the chemistry of the hydrocarbons that will be expelled from the kerogen to the secondary migration pathways; (6) Develop an algorithm that predicts the flow of hydrocarbons along secondary migration pathways, accounts for mixing of miscible hydrocarbon components along the pathway, and calculates the phase fractionation that will occur as the hydrocarbons move upward down the geothermal and fluid pressure gradients in the basin; and (7) Integrate the above components into a functional model implemented on a PC or low cost workstation.

  18. Exoplanet Equilibrium Chemistry Calculations

    Science.gov (United States)

    Blumenthal, Sarah; Harrington, J.; Bowman, M.; Blecic, J.

    2013-10-01

    Recently, Agundez et al. (2012, A&A 548, A73) used a chemical kinetics code to study a model HD 209458b (equilibrium temperature of 1450 K, assuming full redistribution and 0 albedo). They found that thermochemistry dominates most of the dayside, but that significant compositional gradients may exist across the dayside. We calculate equilibrium-chemistry molecular abundances for several model exoplanets, using NASA's open-source Chemical Equilibrium Abundances code (McBride and Gordon 1996). We vary the degree of radiation redistribution to the dark side, ranging from total redistribution to instantaneous reradiation. Atomically, both the solar abundance multiple and the carbon fraction vary. Planet substellar temperatures range from just above 1200 K, where photochemistry should no longer be important, to those of hot planets (3000 K). We present synthetic abundance images for the key spectroscopic molecules CO, CH4, and H2O for several hot-Jupiter model planets. This work was supported by the NASA Planetary Atmospheres grant NNX12AI69G.

  19. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    This is the annual progress report for the Indiana University nuclear chemistry program for the 1992/1993 year. Accomplishments include the construction, testing, and initial experimental runs of the Indiana Silicon Sphere (ISiS) 4π charged particle detector. ISiS is designed to study energy dissipation and multifragmentation phenomena in light-ion-induced nuclear reactions at medium-to-high energies. Its second test run was to examine 3.6 GeV 3He beam reactions at Laboratoire National Saturne (LNS) in Saclay. The development and deployment of this system has occupied a great deal of the groups effort this reporting period. Additional work includes: calculations of isotopic IMF yields in the 4He + 116,124Sn reaction; cross sections for A = 6 - 30 fragments from the 4He + 28Si reaction at 117 and 198 MeV; charging effects of passivated silicon detectors; neck emission of intermediate-mass fragments in the fission of hot heavy nuclei

  20. Atmospheric and aerosol chemistry

    International Nuclear Information System (INIS)

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  1. Chemistry in one dimension.

    Science.gov (United States)

    Loos, Pierre-François; Ball, Caleb J; Gill, Peter M W

    2015-02-01

    We report benchmark results for one-dimensional (1D) atomic and molecular systems interacting via the Coulomb operator |x|(-1). Using various wavefunction-type approaches, such as Hartree-Fock theory, second- and third-order Møller-Plesset perturbation theory and explicitly correlated calculations, we study the ground state of atoms with up to ten electrons as well as small diatomic and triatomic molecules containing up to two electrons. A detailed analysis of the 1D helium-like ions is given and the expression of the high-density correlation energy is reported. We report the total energies, ionization energies, electron affinities and other physical properties of the many-electron 1D atoms and, using these results, we construct the 1D analog of Mendeleev's periodic table. We find that the 1D periodic table contains only two groups: the alkali metals and the noble gases. We also calculate the dissociation curves of several 1D diatomics and study the chemical bond in H2(+), HeH(2+), He2(3+), H2, HeH(+) and He2(2+). We find that, unlike their 3D counterparts, 1D molecules are primarily bound by one-electron bonds. Finally, we study the chemistry of H3(+) and we discuss the stability of the 1D polymer resulting from an infinite chain of hydrogen atoms. PMID:25518906

  2. Computational Chemistry and Lubrication

    Science.gov (United States)

    Zehe, Michael J.

    1998-01-01

    Members of NASA Lewis Research Center's Tribology and Surface Science Branch are applying high-level computational chemistry techniques to the development of new lubrication systems for space applications and for future advanced aircraft engines. The next generation of gas turbine engines will require a liquid lubricant to function at temperatures in excess of 350 C in oxidizing environments. Conventional hydrocarbon-based lubricants are incapable of operating in these extreme environments, but a class of compounds known as the perfluoropolyether (PFAE) liquids (see the preceding illustration) shows promise for such applications. These commercially available products are already being used as lubricants in conditions where low vapor pressure and chemical stability are crucial, such as in satellite bearings and composite disk platters. At higher temperatures, however, these compounds undergo a decomposition process that is assisted (catalyzed) by metal and metal oxide bearing surfaces. This decomposition process severely limits the applicability of PFAE's at higher temperatures. A great deal of laboratory experimentation has revealed that the extent of fluid degradation depends on the chemical properties of the bearing surface materials. Lubrication engineers would like to understand the chemical breakdown mechanism to design a less vulnerable PFAE or to develop a chemical additive to block this degradation.

  3. Computational chemistry research

    Science.gov (United States)

    Levin, Eugene

    1987-01-01

    Task 41 is composed of two parts: (1) analysis and design studies related to the Numerical Aerodynamic Simulation (NAS) Extended Operating Configuration (EOC) and (2) computational chemistry. During the first half of 1987, Dr. Levin served as a member of an advanced system planning team to establish the requirements, goals, and principal technical characteristics of the NAS EOC. A paper entitled 'Scaling of Data Communications for an Advanced Supercomputer Network' is included. The high temperature transport properties (such as viscosity, thermal conductivity, etc.) of the major constituents of air (oxygen and nitrogen) were correctly determined. The results of prior ab initio computer solutions of the Schroedinger equation were combined with the best available experimental data to obtain complete interaction potentials for both neutral and ion-atom collision partners. These potentials were then used in a computer program to evaluate the collision cross-sections from which the transport properties could be determined. A paper entitled 'High Temperature Transport Properties of Air' is included.

  4. Prebiotic chemistry - Lecture 2

    International Nuclear Information System (INIS)

    The nucleic acids and proteins are at the basis of all life. The energy source on the primitive earth acting on the earth's early atmosphere are believed to have produced all the molecules necessary for life. Laboratory experiments over the last four decades have clearly established the prebiotic synthesis of these components, amino acids, purines, pyrimidines, carbohydrates. The mechanisms of polymerization have also been outlined. We thus have a sequence from atoms to small molecules to the large molecules which are necessary for the emergence of life. The analysis of meteorites has given us fresh evidence that these reactions which we have presumed to have taken place on the primitive earth may have also occurred in the early solar system. The analysis of carbonaceous chondrites has given us unmistakable evidence for the presence of these molecules in outer space. Recent observational and theoretical studies have also pointed out that comets may be the location for prebiotic reactions and may also have contributed to organic matter on the primitive earth. The radio astronomers studying interstellar media have also provided us with ample evidence that there are a large number of organic molecules in interstellar space. Organic chemistry appears to be commonplace in the universe. (author)

  5. Pore-water chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Vinsot, A. [Agence Nationale pour la Gestion des Dechets Radioactifs, Lab. de Souterrain de Meuse/Haute-Marne, 55 - Bure (France); Appelo, C.A.J. [Valeriusstraat 11, Amsterdam (Netherlands); Cailteau, C. [LEM, ENSG/INPL, 54 - Vandoeuvre-les-Nancy (France); Cailteau, C. [G2R-CREGU, UMR 7566 CNRS, 54 - Vandoeuvre-les-Nancy (France); Cailteau, C. [Andra - Agence Nationale pour la Gestion des Dechets Radioactifs, 92 - Chatenay Malabry (France); Mettler, S.; Wersin, P. [NAGRA, CH-5430 Wettingen (Switzerland); Canniere, P. de [Studiecentrum voor Kernenergie - Centre d' Etude de l' Energie Nucleaire, Mol (Belgium); Gabler, H.E. [BGR, Hannover (Germany); Gaucher, E.C.; Tournassat, C. [Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France); Jacquot, E.; Altmann, S. [Agence Nationale pour la Gestion des Dechets Radioactifs (DS/TR), 92 - Chatenay Malabry (France); Vinsot, A. [Agence Nationale pour la Gestion des Dechets Radioactifs, Lab. de Recherche Souterrain de Meuse/Haute-Marne, 55 - Bure (France); Courdouan, A.; Christl, I.; Kretzschmar, R. [Institute of Biogeochemistry and Pollutant Dynamics, Dept. of Environmental Sciences, ETH Zurich, CHN (Switzerland); Wersin, P. [National Cooperative for the Disposal of Radioactive Waste (Nagra), Wettingen (Switzerland); Savoye, S.; Matray, J.M.; Wittebroodt, Ch.; Cabrera, J.; Bensenouci, F. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay aux Roses (France); Michelot, J.L.; Bensenouci, F. [Paris-11 Univ., UMR IDES CNRS, 91 - Orsay (France); Waber, H.S. [Rock-Water Interaction (RWI), Inst. of Geological Sciences, Bern (Switzerland); Wittebroodt, Ch. [Montpellier-2 Univ., MSE, 34 (France); Lavielle, B.; Gilabert, E.; Thomas, B.; Lavastre, V. [Bordeaux 1-2 Univ., (GdR FORPRO 0788), Chimie Nucleaire Analytique et Bioenvironnementale (CNAB), CNRS, 33 - Gradignan (France); Lavastre, V. [Nimes Univ., Geochimie Isotopique Environnementale (GIS/CEREGE), CNRS-RANCE, 30 (France)

    2007-07-01

    This session gathers 5 articles dealing with: CO{sub 2} data on gas and pore water sampled in-situ in the Opalinus clay at the Mont Terri rock laboratory (A. Vinsot, C.A.J. Appelo, C. Cailteau, S. Mettler, P. Wersin, P. De Canniere, H.E. Gaebler); the improvements in the modelling of the pore water chemistry of the Callovo-Oxfordian formation (E.C. Gaucher, C. Tournassat, E. Jacquot, S. Altmann, A. Vinsot) the nature and reactivity of dissolved organic matter in the Opalinus clay and Callovo-Oxfordian formations (A. Courdouan, I. Christl, P.Wersin, R. Kretzschmar); PH4: a 250 m deep borehole in Tournemire for assessing the reliability of chloride, helium and water stable isotopes profiles in the Toarcian/ Domerian shales (S. Savoye, J.L. Michelot, H.N. Waber, J.M. Matray, F. Bensenouci, Ch. Wittebroodt, J. Cabrera); and the development of a new facility for dating old groundwaters by using {sup 81}Kr (B. Lavielle, E. Gilabert, B. Thomas, V. Lavastre)

  6. Microfluidics in radiopharmaceutical chemistry

    International Nuclear Information System (INIS)

    The increased demand for molecular imaging tracers useful in assessing and monitoring diseases has stimulated research towards more efficient and flexible radiosynthetic routes, including newer technologies. The traditional vessel-based approach suffers from limitations concerning flexibility, reagent mass needed, hardware requirements, large number of connections and valves, repetitive cleaning procedures and overall big footprint to be shielded from radiation. For these reasons, several research groups have started to investigate the application of the fast growing field of microfluidic chemistry to radiosynthetic procedures. After the first report in 2004, many scientific papers have been published and demonstrated the potential for increased process yields, reduced reagent use, improved flexibility and general ease of setup. This review will address definitions occurring in microfluidics as well as analyze the different approaches under two macro-categories: microvessel and microchannel. In this perspective, several works will be collected, involving the use of positron emitting species (11C, 18F, 64Cu) and the fewer examples of gamma emitting radionuclides (99mTc, 125/131I). New directions in microfluidic research applied to PET radiochemistry, future developments and challenges are also discussed. -- Graphical abstract: Display Omitted

  7. Marine fragrance chemistry.

    Science.gov (United States)

    Hügel, Helmut M; Drevermann, Britta; Lingham, Anthony R; Marriott, Philip J

    2008-06-01

    The main marine message in perfumery is projected by Calone 1951 (7-methyl-2H-1,5-benzodioxepin-3(4H)-one). Kraft (Givaudan) and Gaudin (Firmenich) further maximized the marine fragrance molecular membership by extending the carbon chain of the 7-Me group. Our research targeted the polar group of the benzodioxepinone parent compound to investigate how this region of molecular makeup resonates with the dominant marine fragrance of the Calone 1951 structure. The olfactory evaluation of analogues prepared by chemical modification or removal of the CO group resulted in the introduction of aldehydic, sweet and floral-fruity notes with a diluted/diminished potency of the marine odor. To further analyze the olfactory properties of benzodioxepinones containing a diverse range of aromatic ring substituents, a novel synthesis route was developed. We found that a 7-alkyl group in Calone 1951 was essential for the maintenance of the significant marine odor characteristic, and our studies support the concept that the odorant structure occupying the hydrophobic binding pocket adjacent to the aromatic ring-binding site of the olfactory receptor is pivotal in the design and discovery of more potent and characteristic marine fragrances. How the structure of benzodioxepinones connects to marine sea-breeze fragrances is our continuing challenging research focus at the chemistry-biology interface. PMID:18618392

  8. Advances in electron transfer chemistry

    CERN Document Server

    Mariano, Patrick S

    1993-01-01

    Advances in Electron Transfer Chemistry, Volume 3 presents studies that discuss findings in the various aspects of electron chemistry. The book is comprised of four chapters; each chapter reviews a work that tackles an issue in electron transfer chemistry. Chapter 1 discusses the photoinduced electron transfer in flexible biaryl donor-acceptor molecules. Chapter 2 tackles light-induced electron transfer in inorganic systems in homogeneous and heterogeneous phases. The book also covers internal geometry relaxation effects on electron transfer rates of amino-centered systems. The sequential elec

  9. The radiation chemistry of macromolecules

    CERN Document Server

    1973-01-01

    The Radiation Chemistry of Macromolecules, Volume II is a collection of papers that discusses radiation chemistry of specific systems. Part 1 deals with radiation chemistry of substituted vinyl polymers, particularly polypropylene (PP) as its structure is intermediate between polyethylene and polyisobutylene. This part also discusses polypropylene oxide (PPOx) for it can be prepared in the atactic, isotactic, and optically active forms. One paper focuses on the fundamental chemical processes and the changes in physical properties that give rise to many different applications of polystyrene. An

  10. Catalysis and sustainable (green) chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Centi, Gabriele; Perathoner, Siglinda [Dipartimento di Chimica Industriale ed Ingegneria dei Materiali, University of Messina, Salita Sperone 31, 98166 Messina (Italy)

    2003-01-15

    Catalysis is a key technology to achieve the objectives of sustainable (green) chemistry. After introducing the concepts of sustainable (green) chemistry and a brief assessment of new sustainable chemical technologies, the relationship between catalysis and sustainable (green) chemistry is discussed and illustrated via an analysis of some selected and relevant examples. Emphasis is also given to the concept of catalytic technologies for scaling-down chemical processes, in order to develop sustainable production processes which reduce the impact on the environment to an acceptable level that allows self-depuration processes of the living environment.

  11. Plants and Medicinal Chemistry--2

    Science.gov (United States)

    Bailey, D.

    1977-01-01

    Second of a two part article on the influence of plants on medicinal chemistry. This part considers how drugs work, the attempts to develop anaesthetics safer than cocaine, and useful poisons. (Author/SL)

  12. What Chemistry To Teach Engineers?

    Science.gov (United States)

    Hawkes, Stephen J.

    2000-01-01

    Examines possible general chemistry topics that would be most relevant and practical for engineering majors. Consults the Accreditation Board for Engineering and Technology (ABET), engineering textbooks, texts from other required subjects, and practicing engineers for recommendations. (Contains 24 references.) (WRM)

  13. International Year of Chemistry 2011

    Institute of Scientific and Technical Information of China (English)

    XUE Zi-Ling

    2011-01-01

    Science China Chemistry would like to dedicate this special issue to the International Year of Chemistry (IYC) 2011,as part of the celebrations of IYC in China.Scientists from Australia,Brazil,Britain,Canada,Chile,China,France,Germany,India,Israel,Japan,Nepal,Pakistan,Saudi Arabia,Singapore,South Africa,and the USA have contributed 28 papers marking the event.Our authors from across the globe include students,members (a corresponding member) and fellows of national academies of sciences in several countries (Australia,Chile,China,France,India,Israel,Pakistan,and the USA),fellows of the British and Canadian Royal Societies,and two Nobel Laureates (Robert Grubbs and Ada Yonath).Here they present their work contributing to the IYC 2011 theme "Chemistry-our life,our future" [1].These papers cover fundamental chemistry,the chemical bases of life processes,and their potential applications.

  14. Analytical Chemistry: A Literary Approach.

    Science.gov (United States)

    Lucy, Charles A.

    2000-01-01

    Provides an anthology of references to descriptions of analytical chemistry techniques from history, popular fiction, and film which can be used to capture student interest and frame discussions of chemical techniques. (WRM)

  15. Highlights of nuclear chemistry 1995

    International Nuclear Information System (INIS)

    In this report 9 topics of the work of the Nuclear Chemistry Group in 1995 are highlighted. A list of publications and an overview of the international cooperation is given. (orig.). 19 refs., 19 figs., 2 tabs., 2 app

  16. Organometallic chemistry of metal surfaces

    International Nuclear Information System (INIS)

    The organometallic chemistry of metal surfaces is defined as a function of surface crystallography and of surface composition for a set of cyclic hydrocarbons that include benzene, toluene, cyclohexadienes, cyclohexene, cyclohexane, cyclooctatetraene, cyclooctadienes, cyclooctadiene, cycloheptatriene and cyclobutane. 12 figures

  17. Part 7: Environmental Chemistry, Revised.

    Science.gov (United States)

    Douville, Judith A.

    2003-01-01

    Discusses resources on applied/interdisciplinary areas of chemistry available as books and electronic materials that mostly target graduate students, faculty, and chemists in the industry. (Author/YDS)

  18. Promoting sustainability through green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kirchhoff, Mary M. [American Chemical Society, 1155 Sixteenth Street, NW, Washington, DC 20036 (United States)

    2005-06-15

    Green chemistry is an important tool in achieving sustainability. The implementation of green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, is essential if the expanding global population is to enjoy an increased standard of living without having a negative impact on the health of the planet. Cleaner technologies will allow the chemical enterprise to provide society with the goods and services on which it depends in an environmentally responsible manner. Green chemistry provides solutions to such global challenges as climate change, sustainable agriculture, energy, toxics in the environment, and the depletion of natural resources. A collaborative effort by industry, academia, and government is needed to promote the adoption of the green chemistry technologies necessary to achieve a sustainable society.

  19. Organometallic Chemistry. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-07-14

    The Gordon Research Conference (GRC) on Organometallic Chemistry was held at Salve Regina, Newport, Rhode Island, 7/21-26/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  20. Atmospheric Chemistry and Air Pollution

    OpenAIRE

    Gaffney, Jeffrey S.; Marley, Nancy A.

    2003-01-01

    Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry...

  1. Overview of PWR chemistry options

    Energy Technology Data Exchange (ETDEWEB)

    Nordmann, F.; Stutzmann, A.; Bretelle, J.L. [Electricite de France, Central Labs. (France)

    2002-07-01

    EDF Central Laboratories, in charge of engineering in chemistry, of defining the chemistry specifications and studying the operation feedback and improvement for 58 PWR units, have the opportunity to evaluate many options of operation developed and applied all around the world. Thanks to these international relationships and to the benefit of a large feedback from many units, some general evaluation of the various options is discussed in this paper. (authors)

  2. Contextualising Nanotechnology in Chemistry Education

    OpenAIRE

    O'Connor, Christine; Hayden, Hugh

    2008-01-01

    This paper will give an example of a pedagogical approach taken in integrating nanotechnology into a chemistry degree course. In recent years nanotechnology has widely become part of the course content for undergraduate chemistry and physics degree curriculum. How contextualised the delivery of the subject matter may vary. The role of contextualisation of nanotechnology in the delivery of the content is the main focus of this paper, as to date in Ireland and many other countries nanotechnolog...

  3. Nonthermal plasma chemistry and physics

    CERN Document Server

    Meichsner, Jurgen; Schneider, Ralf; Wagner, Hans-Erich

    2013-01-01

    In addition to introducing the basics of plasma physics, Nonthermal Plasma Chemistry and Physics is a comprehensive presentation of recent developments in the rapidly growing field of nonthermal plasma chemistry. The book offers a detailed discussion of the fundamentals of plasma chemical reactions and modeling, nonthermal plasma sources, relevant diagnostic techniques, and selected applications.Elucidating interconnections and trends, the book focuses on basic principles and illustrations across a broad field of applications. Expert contributors address environmental aspects of plasma chemist

  4. Chemistry in all its States

    OpenAIRE

    Ruiz-Hitzky, Eduardo

    2015-01-01

    1 • The Microwave Oven: from the Kitchen to Synthesis Chemistry “A microwave oven is a domestic appliance that is mainly used to heat up food quickly, by agitating the water molecules contained in the food under the effect of a microwave radiation” (Wikipedia). From the outset, this technology was mainly used in the kitchen and sometimes in highly precise industrial applications. However, for the last twenty years or so microwave has also been used in chemistry laboratories, to activate chem...

  5. Creating a Context for Chemistry

    Science.gov (United States)

    Truman Schwartz, A.

    Until relatively recently, the teaching of chemistry at the college and university level in the United States has been quite traditional and oriented primarily toward the preparation of chemists. Students not concentrating in the sciences have often been poorly served by existing courses. Chemistry in Context: Applying Chemistry to Society, a textbook for nonscience majors developed under the sponsorship of the American Chemical Society, is an effort to address the needs and interests of this audience. The book introduces the phenomena and principles of chemistry within the context of socially significant issues such as global warming, ozone depletion, alternate energy sources, nutrition, and genetic engineering. The chemistry is presented as needed to inform an understanding of the central topics, and the text features student-centered activities designed to promote critical thinking and risk-benefit analysis as well as an understanding of chemical principles. This paper summarizes the origin, development, content, pedagogy, evaluation, and influence of Chemistry in Context and considers its potential implications for other disciplines and the instruction of science majors.

  6. Physical chemistry and the environment

    International Nuclear Information System (INIS)

    From the ozone hole and the greenhouse effect to plastics recycling and hazardous waste disposal, society faces a number of issues, the solutions to which require an unprecedented understanding of the properties of molecules. We are coming to realize that the environment is a coupled set of chemical systems, its dynamics determining the welfare of the biosphere and of humans in particular. These chemical systems are governed by fundamental molecular interactions, and they present chemists with an unparalleled challenge. The application of current concepts of molecular behavior and of up-to-date experimental and computational techniques can provide us with insights into the environment that are needed to mitigate past damage, to anticipate the impact of current human activity, and to avoid future insults to the environment. Environmental chemistry encompasses a number of separate, yet interlocking, areas of research. In all of these areas progress is limited by an inadequate understanding of the underlying chemical processes involved. Participation of all chemical approaches -- experimental, theoretical and computational -- and of all disciplines of chemistry -- organic, inorganic, physical, analytical and biochemistry -- will be required to provide the necessary fundamental understanding. The Symposium on ''Physical Chemistry and the Environment'' was designed to bring the many exciting and challenging physical chemistry problems involved in environmental chemistry to the attention of a larger segment of the physical chemistry community

  7. The Brazilian medicinal chemistry from 1998 to 2008 in the Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters and European Journal of Medicinal Chemistry [A química medicinal brasileira de 1998 a 2008 nos periódicos Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters e European Journal of Medicinal Chemistry

    OpenAIRE

    Bárbara Vasconcellos da Silva; Renato Saldanha Bastos; Angelo da Cunha Pinto

    2009-01-01

    In this article we present the Brazilian publications, the research groups involved, the contributions per states and the main diseases studied from 1998 to 2008 in the following periodicals: Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters and European Journal of Medicinal Chemistry.

  8. Effective Chemistry Communication in Informal Environments

    Science.gov (United States)

    National Academies Press, 2016

    2016-01-01

    Chemistry plays a critical role in daily life, impacting areas such as medicine and health, consumer products, energy production, the ecosystem, and many other areas. Communicating about chemistry in informal environments has the potential to raise public interest and understanding of chemistry around the world. However, the chemistry community…

  9. Who is Teaching the History of Chemistry?

    Science.gov (United States)

    Everett, Kenneth G.; DeLoach, Will S.

    1987-01-01

    Reports on a study into how the history of chemistry is being taught in colleges and universities. Results indicate that courses on the history of chemistry are hardly ever required of chemistry majors, and they are offered in only 10 percent of American Chemical Society approved chemistry departments. (TW)

  10. Peer Mentoring in the General Chemistry and Organic Chemistry Laboratories: The Pinacol Rearrangement--An Exercise in NMR and IR Spectroscopy for General Chemistry and Organic Chemistry Laboratories

    Science.gov (United States)

    Arrington, Caleb A.; Hill, Jameica B.; Radfar, Ramin; Whisnant, David M.; Bass, Charles G.

    2008-01-01

    This article describes a discovery experiment for general chemistry and organic chemistry labs. Although the pinacol rearrangement has been employed in undergraduate organic laboratories before, in this application organic chemistry students act as mentors to students of general chemistry. Students work together using distillation--a new technique…

  11. 42 CFR 493.839 - Condition: Chemistry.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Chemistry. 493.839 Section 493.839... These Tests § 493.839 Condition: Chemistry. The specialty of chemistry includes for the purposes of proficiency testing the subspecialties of routine chemistry, endocrinology, and toxicology....

  12. Language Preferences of Freshman Chemistry Students: An Exploratory Study.

    Science.gov (United States)

    Hill, Douglas M.; And Others

    1980-01-01

    Ascertained whether chemistry instructors have a consistent preference for particular ways of idea expression by chemistry students. Comparisons of responses on a chemistry preference test were made among chemistry instructors, chemistry majors and nonscience majors. (CS)

  13. Advances in BWR water chemistry

    International Nuclear Information System (INIS)

    This paper reviews recent advances in Boiling Water Reactor (BWR) water chemistry control with examples of plant experiences at U.S. designed BWRs. Water chemistry advances provide some of the most effective methods for mitigating materials degradation, reducing fuel performance concerns and lowering radiation fields. Mitigation of stress corrosion cracking (SCC) of materials remains a high priority and improved techniques that have been demonstrated in BWRs will be reviewed, specifically hydrogen injection combined with noble metal chemical addition (NMCA) and the newer on-line noble metal application process (OLNC). Hydrogen injection performance, an important part of SCC mitigation, will also be reviewed for the BWR fleet, highlighting system improvements that have enabled earlier injection of hydrogen including the potential for hydrogen injection during plant startup. Water chemistry has been significantly improved by the application of pre-filtration and optimized use of ion exchange resins in the CP (condensate polishing) and reactor water cleanup (RWCU) systems. EPRI has monitored and supported water treatment improvements to meet water chemistry goals as outlined in the EPRI BWR Water Chemistry Guidelines, particularly those for SCC mitigation of reactor internals and piping, minimization of fuel risk due to corrosion and crud deposits and chemistry control for radiation field reduction. In recent years, a significant reduction has occurred in feedwater corrosion product input, particularly iron. A large percentage of plants are now reporting <0.1 ppb feedwater iron. The impacts to plant operation and chemistry of lower feedwater iron will be explored. Depleted zinc addition is widely practiced across the fleet and the enhanced focus on radiation reduction continues to emphasize the importance of controlling radiation source term. In addition, shutdown chemistry control is necessary to avoid excessive release of activated corrosion products from fuel

  14. Publicising chemistry in a multicultural society through chemistry outreach

    Directory of Open Access Journals (Sweden)

    Joyce D. Sewry

    2011-11-01

    Full Text Available Given the emphasis in Higher Education on community engagement in South Africa and the importance of international collaboration, we discuss a joint approach to chemistry outreach in two countries on two continents with widely differing target school audiences. We describe the history of the partnership between the chemistry departments at Rhodes University and the University of Bristol and provide an outline of the chemistry content of their outreach initiatives, the modes of delivery, the advantages to both departments and their students for involvement in various levels of outreach, the challenges they still face and additional opportunities that such work facilitated. The lecture demonstration ‘A Pollutant’s Tale’ was presented to thousands of learners all over the world, including learners at resource-deprived schools in South Africa. Challenges to extend outreach activities in South Africa include long travelling distances, as well as a lack of facilities (such as school halls and electricity at schools. Outreach activities not only impacted on the target audience of young learners, they also impacted upon the postgraduate and other chemistry students taking part in these initiatives. This collaboration strengthened both institutions and their outreach work and may also lead to chemistry research collaborations between the academics involved.

  15. Philosophy of Chemistry: An Emerging Field with Implications for Chemistry Education.

    Science.gov (United States)

    Erduran, Sibel

    Traditional applications of history and philosophy of science in chemistry education have concentrated on the teaching and learning of "history of chemistry". This paper considers the recent emergence of "philosophy of chemistry" as a distinct field and explores the implications of philosophy of chemistry for chemistry education in the context of…

  16. APPLICATIONS OF GREEN CHEMISTRY IN SUSTAINABLE DEVELOPMENT

    OpenAIRE

    Suresh D. Dhage; Komalsing K. Shisodiya

    2013-01-01

    Chemistry is really very helpful to us as its applications are used worldwide for several purposes. We cannot really imagine a world without chemistry and its applications such as medicines. However, we should now concentrate on green chemistry or sustainable chemistry, which refers to reducing or stopping the damage done to the environment around us. Hence, green chemistry could include anything from reducing waste to even disposing of waste in the correct manner. Another way to save the env...

  17. Cycloadditions in modern polymer chemistry.

    Science.gov (United States)

    Delaittre, Guillaume; Guimard, Nathalie K; Barner-Kowollik, Christopher

    2015-05-19

    Synthetic polymer chemistry has undergone two major developments in the last two decades. About 20 years ago, reversible-deactivation radical polymerization processes started to give access to a wide range of polymeric architectures made from an almost infinite reservoir of functional building blocks. A few years later, the concept of click chemistry revolutionized the way polymer chemists approached synthetic routes. Among the few reactions that could qualify as click, the copper-catalyzed azide-alkyne cycloaddition (CuAAC) initially stood out. Soon, many old and new reactions, including cycloadditions, would further enrich the synthetic macromolecular chemistry toolbox. Whether click or not, cycloadditions are in any case powerful tools for designing polymeric materials in a modular fashion, with a high level of functionality and, sometimes, responsiveness. Here, we wish to describe cycloaddition methodologies that have been reported in the last 10 years in the context of macromolecular engineering, with a focus on those developed in our laboratories. The overarching structure of this Account is based on the three most commonly encountered cycloaddition subclasses in organic and macromolecular chemistry: 1,3-dipolar cycloadditions, (hetero-)Diels-Alder cycloadditions ((H)DAC), and [2+2] cycloadditions. Our goal is to briefly describe the relevant reaction conditions, the advantages and disadvantages, and the realized polymer applications. Furthermore, the orthogonality of most of these reactions is highlighted because it has proven highly beneficial for generating unique, multifunctional polymers in a one-pot reaction. The overview on 1,3-dipolar cycloadditions is mostly centered on the application of CuAAC as the most travelled route, by far. Besides illustrating the capacity of CuAAC to generate complex polymeric architectures, alternative 1,3-dipolar cycloadditions operating without the need for a catalyst are described. In the area of (H)DA cycloadditions

  18. Logic, History, and the Chemistry Textbook: I. Does Chemistry Have a Logical Structure?

    Science.gov (United States)

    Jensen, William B.

    1998-01-01

    Presents the first of three invited keynote lectures from the 1995 conference of the New England Association of Chemistry Teachers. Discusses the relevance of the history of chemistry to the teaching of chemistry. Contains 27 references. (DDR)

  19. Radiation chemistry of heavy particles

    International Nuclear Information System (INIS)

    The physical aspects of the energy deposit of fast particles in matter initiate chemical effects which are merged with the early physical processes. Here only radiation chemistry and its relationship to the initial energy deposit are of concern. The primary objective of our track studies is, however, application to biology. In the radiolytic decomposition of water energy is absorbed almost exclusively in water, and the principal chemistry is that of radiation decomposition of water. The track structure in water is expected to be virtually the same as that in a biological system. The study of radiation chemistry of dilute solutions, therefore, provides another method to investigate the structure of tracks as they are likely to be present in an irradiated biological system but at times much longer than they are accessible to purely physical measurements

  20. Radiation chemistry research using PULAF

    International Nuclear Information System (INIS)

    The details of the recently installed 7 MeV Pune University LINAC Facility (PULAF) coupled with the optical absorption technique for pulse radiolysis studies at the National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune, India are described. The facility has a selection of electron pulse widths in the range 10 ns-3 μs with corresponding doses of about 5-144 Gy per pulse. The operation of the machine and the detection system are fully automated. Several researchers from various Indian universities and national laboratories use the PULAF and some of the projects that are currently undertaken by our group and others include the radiation chemistry of indole and chalcone derivatives, herbal antioxidants, structure-reactivity studies in cinnamates, redox chemistry of inorganic metal complexes, studies on oxidation of pyrimidine analogues and aromatic sulphur compounds. Some of them are briefly discussed here

  1. Problems in structural inorganic chemistry

    CERN Document Server

    Li, Wai-Kee; Mak, Thomas Chung Wai; Mak, Kendrew Kin Wah

    2013-01-01

    This book consists of over 300 problems (and their solutions) in structural inorganic chemistry at the senior undergraduate and beginning graduate level. The topics covered comprise Atomic and Molecular Electronic States, Atomic Orbitals, Hybrid Orbitals, Molecular Symmetry, Molecular Geometry and Bonding, Crystal Field Theory, Molecular Orbital Theory, Vibrational Spectroscopy, and Crystal Structure. The central theme running through these topics is symmetry, molecular or crystalline. The problems collected in this volume originate in examination papers and take-home assignments that have been part of the teaching of the book's two senior authors' at The Chinese University of Hong Kong over the past four decades. The authors' courses include Chemical Bonding, Elementary Quantum Chemistry, Advanced Inorganic Chemistry, X-Ray Crystallography, etc. The problems have been tested by generations of students taking these courses.

  2. Making Decisions by Analytical Chemistry

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    discrepancies are very unfortunate because erroneous conclusions may arise from an otherwise meticulous and dedicated effort of research staff. This may eventually lead to unreliable conclusions thus jeopardizing investigations of environmental monitoring, climate changes, food safety, clinical chemistry......It has been long recognized that results of analytical chemistry are not flawless, owing to the fact that professional laboratories and research laboratories analysing the same type of samples by the same type of instruments are likely to obtain significantly different results. The European......, forensics and other fields of science where analytical chemistry is the key instrument of decision making. In order to elucidate the potential origin of the statistical variations found among laboratories, a major program was undertaken including several analytical technologies where the purpose was to...

  3. The migration chemistry of neptunium

    International Nuclear Information System (INIS)

    The chemistry of neptunium, including redox properties, complex chemistry and chemistry of neptunium in its five oxidation states, III, IV, V, VI and VII has been reviewed with special emphasis on factors, which may be of importance in controlling the environmental behaviour of this element. Under environmental conditions neptunium should exist predominantly in oxidation state V in the form NpO2+ and to some extent also as Np (IV) in the form of Np4+ and Np (VI) in the form of NpO22+, whereas the other oxidation states Np (III) and Np (VII) can not exist in the environment. However, experimental evidence is lacking as is any knowledge about the mobility of neptunium in the environment. (author) 15 tabs., 2 ills., 37 refs

  4. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  5. Radiation chemistry research using PULAF

    Science.gov (United States)

    Gaikwad, Parimal; Priyadarsini, K. I.; Rao, B. S. M.

    2008-10-01

    The details of the recently installed 7 MeV Pune University LINAC Facility (PULAF) coupled with the optical absorption technique for pulse radiolysis studies at the National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune, India are described. The facility has a selection of electron pulse widths in the range 10 ns-3 μs with corresponding doses of about 5-144 Gy per pulse. The operation of the machine and the detection system are fully automated. Several researchers from various Indian universities and national laboratories use the PULAF and some of the projects that are currently undertaken by our group and others include the radiation chemistry of indole and chalcone derivatives, herbal antioxidants, structure-reactivity studies in cinnamates, redox chemistry of inorganic metal complexes, studies on oxidation of pyrimidine analogues and aromatic sulphur compounds. Some of them are briefly discussed here.

  6. Radiation chemistry research using PULAF

    Energy Technology Data Exchange (ETDEWEB)

    Gaikwad, Parimal [National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune 411 007 (India); Priyadarsini, K.I. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Rao, B.S.M. [National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune 411 007 (India)], E-mail: bsmr@chem.unipune.ernet.in

    2008-10-15

    The details of the recently installed 7 MeV Pune University LINAC Facility (PULAF) coupled with the optical absorption technique for pulse radiolysis studies at the National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune, India are described. The facility has a selection of electron pulse widths in the range 10 ns-3 {mu}s with corresponding doses of about 5-144 Gy per pulse. The operation of the machine and the detection system are fully automated. Several researchers from various Indian universities and national laboratories use the PULAF and some of the projects that are currently undertaken by our group and others include the radiation chemistry of indole and chalcone derivatives, herbal antioxidants, structure-reactivity studies in cinnamates, redox chemistry of inorganic metal complexes, studies on oxidation of pyrimidine analogues and aromatic sulphur compounds. Some of them are briefly discussed here.

  7. Handbook of hot atom chemistry

    International Nuclear Information System (INIS)

    Hot atom chemistry is an increasingly important field, which has contributed significantly to our understanding of many fundamental processes and reactions. Its techniques have become firmly entrenched in numerous disciplines, such as applied physics, biomedical research, and all fields of chemistry. Written by leading experts, this comprehensive handbook encompasses a broad range of topics. Each chapter comprises a collection of stimulating essays, given an in-depth account of the state-of-the-art of the field, and stressing opportunities for future work. An extensive introduction to the whole area, this book provides unique insight into a vast subject, and a clear delineation of its goals, techniques, and recent findings. It also contains detailed discussions of applications in fields as diverse as nuclear medicine, geochemistry, reactor technology, and the chemistry of comets and interstellar grains. (orig.)

  8. Atmospheric Chemistry and Air Pollution

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Gaffney

    2003-01-01

    Full Text Available Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry in industrial areas. Regional air pollution issues such as acid rain, long-range transport of aerosols and visibility loss, and the connections of aerosols to ozone and peroxyacetyl nitrate chemistry are examined. Finally, the potential impacts of air pollutants on the global-scale radiative balances of gases and aerosols are discussed briefly.

  9. The chemistry of plutonium revealed

    International Nuclear Information System (INIS)

    In 1941 one goal of the Manhattan Project was to unravel the chemistry of the synthetic element plutonium as rapidly as possible. Important insights were obtained from tracer experiments, but the full complexity of plutonium chemistry was not revealed until macroscopic amounts (milligrams) became available. Because processes for separation from fission products were aqueous solution based, such solution chemistry was emphasized, particularly precipitation and oxidation-reduction behavior. The latter turned out to be unusually intricate when it was discovered that two more oxidation states existed in aqueous solution than had previously been suspected. Further, it was found that an equilibrium was rapidly established among the four aqueous oxidation states while at the same time any three were not in equilibrium. These and other observations made while doing a crash study of a previously unknown element will be reported

  10. Covalent chemistry in graphene electronics

    Directory of Open Access Journals (Sweden)

    Santanu Sarkar

    2012-06-01

    Full Text Available The development of selective high precision chemical functionalization strategies for device fabrication, in conjunction with associated techniques for patterning graphene wafers with atomic accuracy would provide the necessary basis for a post-CMOS manufacturing technology. This requires a thorough understanding of the principles governing the reactivity and patterning of graphene at the sub-nanometer length scale. This article reviews our quest to delineate the principles of graphene chemistry – that is, the chemistry at the Dirac point and beyond, and the effect of covalent chemistry on the electronic structure, electrical transport, and magnetic properties of this low-dimensional material in order to enable the scalable production of graphene-based devices for low- and high-end technology applications.

  11. Towards Bildung-Oriented Chemistry Education

    Science.gov (United States)

    Sjöström, Jesper

    2013-07-01

    This paper concerns Bildung-oriented chemistry education, based on a reflective and critical discourse of chemistry. It is contrasted with the dominant type of chemistry education, based on the mainstream discourse of chemistry. Bildung-oriented chemistry education includes not only content knowledge in chemistry, but also knowledge about chemistry, both about the nature of chemistry and about its role in society. In 2004 Mahaffy suggested a tetrahedron model based on Johnstone's chemical triangle. The latter represents the formal aspects of chemistry teaching (macro, submicro, and symbolic) and the top of the tetrahedron represents a human element. In the present paper the following subdivision of the top is suggested (starting from the bottom): (1) applied chemistry, (2) socio-cultural context, and (3) critical-philosophic approach. The professional identity of the Bildung-oriented chemistry teacher differs from that of the chemist and is informed by research fields such as Philosophy of Chemistry, Science and Technology Studies, and Environmental Education. He/she takes a socio-critical approach to chemistry, emphasising both the benefits and risks of chemistry and its applications.

  12. The Application of SCC-DV-Xα Computational Method of Quantum Chemistry in Cement Chemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical strength and stabilization of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.

  13. Analytical chemistry and semiconductor materials

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, P.W. (Univ. of Illinois at Urbana-Champaign (USA)); Harris, T.D. (AT T Bell Laboratories, Murray Hill, NJ (USA))

    1990-07-15

    Advances in analytical chemistry are crucial to the continued expansion of electronic and optoelectronic materials in device applications. This report explains the critical role that the defect chemistry of semiconductor material in a device and the difficulty of extracting chemical information about defects. The authors focus on the generic class of chemical analysis problems resulting from the fact that the spatial distribution of chemical composition is the single most important factor in determining the operative properties of electronic and optoelectronic materials. 31 refs., 7 figs., 1 tabs.

  14. Department of Chemistry, progress report

    International Nuclear Information System (INIS)

    The research activities in Department of Chemistry during the last 3 years from 1986 to 1988 were compiled. The researches and works of Department of Chemistry are mainly those concerned with important basic matters and items which are committed to the further development of the nuclear fuels and materials, to the establishment of the nuclear fuel cycle, and to the acquisition of data for the environmental safety studies. Intensive efforts were also made on chemical analysis service of various fuels and nuclear materials. (author)

  15. Molten fluoride fuel salt chemistry

    International Nuclear Information System (INIS)

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Fission product behavior is described along with processing experience. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior, processing and recycle of the fuel components is a necessary factor if future systems are to be established

  16. Sustainable Chemistry at Sungkyunkwan University.

    Science.gov (United States)

    Park, Nam-Gyu

    2015-07-20

    Special Issue: Sustainable Chemistry at Sungkyunkwan University. Sustainable chemistry is key to the development of efficient renewable energies, which will become more and more important in order to combat global warming. In this Editorial, guest editor Prof. Nam-Gyu Park describes the context of this Special Issue on top-quality research towards sustainability performed at Sungkyunkwan University (SKKU) in Korea. Scientists at SKKU work on, for example, photovoltaic solar cells to generate low-cost electricity, lithium batteries and capacitors to store electricity, piezoelectric nanogenerators, thermoelectric devices, hydrogen generation, and fuel cells. PMID:26183687

  17. Hot atom chemistry of sulphur

    International Nuclear Information System (INIS)

    An attempt to cover all papers dealing with the hot atom chemistry of sulpphur is made. Publications which: a) only touch the problem, b) contain some data, indirectly connected with sulphur hot atom chemistry, c) deal with 35S-production from a chloride matrix, are included as well. The author's name and literature source are given in the original language, transcribed, when it is necessary, in latine. A number of primery and secondary documents have been used including Chemical Abstracts, INIS Atomindex, the bibliographies of A. Siuda and J.-P. Adloff for 1973 - 77, etc. (authors)

  18. The Doctorate in Chemistry. Carnegie Essays on the Doctorate: Chemistry.

    Science.gov (United States)

    Breslow, Ronald

    The Carnegie Foundation commissioned a collection of essays as part of the Carnegie Initiative on the Doctorate (CID). Essays and essayists represent six disciplines that are part of the CID: chemistry, education, English, history, mathematics, and neuroscience. Intended to engender conversation about the conceptual foundation of doctoral…

  19. Comparing Carbonyl Chemistry in Comprehensive Introductory Organic Chemistry Textbooks

    Science.gov (United States)

    Nelson, Donna J.; Kumar, Ravi; Ramasamy, Saravanan

    2015-01-01

    Learning the chemistry of compounds containing carbonyl groups is difficult for undergraduate students partly because of a convolution of multiple possible reaction sites, competitive reactions taking place at those sites, different criteria needed to discern between the mechanisms of these reactions, and no straightforward selection method…

  20. Integrating Particulate Representations into AP Chemistry and Introductory Chemistry Courses

    Science.gov (United States)

    Prilliman, Stephen G.

    2014-01-01

    The College Board's recently revised curriculum for advanced placement (AP) chemistry places a strong emphasis on conceptual understanding, including representations of particle phenomena. This change in emphasis is informed by years of research showing that students could perform algorithmic calculations but not explain those calculations…

  1. Chemistry on the inside: green chemistry in mesoporous materials

    OpenAIRE

    MacQuarrie, D.J.

    2000-01-01

    An overview of the rapidly expanding area of tailored mesoporous solids is presented. The synthesis of a wide range of the materials is covered, both inorganically and organically modified. Their applications, in particular those relating to green chemistry, are also highlighted. Finally, potential future directions for these materials are discussed.

  2. Integrating Computational Chemistry into the Physical Chemistry Curriculum

    Science.gov (United States)

    Johnson, Lewis E.; Engel, Thomas

    2011-01-01

    Relatively few undergraduate physical chemistry programs integrate molecular modeling into their quantum mechanics curriculum owing to concerns about limited access to computational facilities, the cost of software, and concerns about increasing the course material. However, modeling exercises can be integrated into an undergraduate course at a…

  3. Developing an online chemistry laboratory for non-chemistry majors

    Science.gov (United States)

    Poole, Jacqueline H.

    Distance education, also known as online learning, is student-centered/self-directed educational opportunities. This style of learning is expanding in scope and is increasingly being accepted throughout the academic curriculum as a result of its flexibility for the student as well as the cost-effectiveness for the institution. Nevertheless, the introduction of online science courses including chemistry and physics have lagged behind due to the challenge of re-creation of the hands-on laboratory learning experience. This dissertation looks at the effectiveness of the design of a series of chemistry laboratory experiments for possible online delivery that provide students with simulated hands-on experiences. One class of college Chemistry 101 students conducted chemistry experiments inside and outside of the physical laboratory using instructions on Blackboard and Late Nite Labs(TM). Learning outcomes measured by (a) pretests, (b) written laboratory reports, (c) posttest assessments, (d) student reactions as determined by a questionnaire, and (e) a focus group interview were utilized to compare both types of laboratory experiences. The research findings indicated learning outcomes achieved by students outside of the traditional physical laboratory were statistically greater than the equivalent face-to-face instruction in the traditional laboratory. Evidence from student reactions comparing both types of laboratory formats (online and traditional face-to-face) indicated student preference for the online laboratory format. The results are an initial contribution to the design of a complete sequence of experiments that can be performed independently by online students outside of the traditional face-to-face laboratory that will satisfy the laboratory requirement for the two-semester college Chemistry 101 laboratory course.

  4. A handbook of nuclear water chemistry

    International Nuclear Information System (INIS)

    This contents is divided three parts. The first part deals with chemistry which is related water nuclear energy. So it explains the role of water in atomic reactor including the basic properties of water, the oxide chemistry electricity chemistry, radiochemistry and measuring techniques of the quality of water in nuclear plant and radiation. The second part introduces technique of nuclear water chemistry, which explains purpose, definition and speciality of water chemistry in light-water reactor. The third part indicates application technology of water chemistry in nuclear energy including putting zinc in light-water reactor and technology of surveillance of leakage in steam generator.

  5. I Chemistry Conference of West Bahia

    Directory of Open Access Journals (Sweden)

    Boaz Oliveira

    2014-11-01

    Full Text Available The I Chemistry Conference of West Bahia [1] aimed the meeting of the academic community of west Bahia state developing research activities at graduate level and postgraduate ones in several chemistry areas, mainly the analytic chemistry, natural products, theoretical chemistry, medicinal chemistry, chemistry teaching, spectroscopy, materials science, photochemistry and catalysis. Through the plenary lectures, short courses and poster presentation, invited researchers from other institutions and mainly students could share experiences as well as plan collaborations from multi and interdisciplinar nature, enabling a greater scientific aggrandizement of the research developed by emergent groups distributed along the inland cities of Brazil.

  6. Biocatalytic Synthesis of a-Arbutin by the Intracellular Crude Enzyme from Xanthomonas Campestris%野油菜黄单胞菌胞内粗酶液催化合成α-熊果苷

    Institute of Scientific and Technical Information of China (English)

    张欣英; 严伟; 李群良; 姚评佳; 魏远安; 唐纪良

    2012-01-01

    Biocatalytic synthesis of α-arbutin by the intracellular crude enzyme from Xanthomonas campes-tris pv. campestris 8004 was studied. The effects of hydroquinone concentration,reactant molar ratio,buffer solution pH value,reaction time and cell concentration on the reaction were investigated. The results showed that the optimum reaction conditions were as follows: the reaction temperature was 35℃ ,the rotational speed was 180 r·min-1,hydroquinone concentration was 40 mmol· L-1 ,the molar ratio of hydroquinone to sucrose was 1:30,the buffer solution pH value was 7.0,the reaction time was 36 h,the cell concentration was 80 mg·mL-1 . Under above conditions,α-arbutin content reached 6. 58 mg·mL-1 ,the selectivity of hydroquinone was 66%,and the conversion rate of hydroquinone was 91%.%利用野油菜黄单胞菌(Xanthomonas campestris pv.campestris) 8004胞内粗酶液生物催化合成α-熊果苷,察了对苯二酚浓度、反应物摩尔比、缓冲溶液pH值、反应时间、菌体浓度等因素对反应的影响.确定最佳反应条件为:应温度35℃、摇床转速180 r·min-1、对苯二酚浓度40mmol·L-1、对苯二酚与蔗糖的摩尔比1∶30、缓冲溶液pH7.0、反应时间36 h、菌体浓度80 mg·mL-1,在此条件下,α-熊果苷含量达到6.58mg· mL-1、对苯二酚选择性为66 %对苯二酚转化率为91%.

  7. Green Chemistry with Microwave Energy

    Science.gov (United States)

    Green chemistry utilizes a set of 12 principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and applications of chemical products (1). This newer chemical approach protects the environment by inventing safer and eco-friendl...

  8. Chemistry--The Big Picture

    Science.gov (United States)

    Cassell, Anne

    2011-01-01

    Chemistry produces materials and releases energy by ionic or electronic rearrangements. Three structure types affect the ease with which a reaction occurs. In the Earth's crust, "solid crystals" change chemically only with extreme heat and pressure, unless their fixed ions touch moving fluids. On the other hand, in living things, "liquid crystals"…

  9. Polymer Chemistry and Liposome Technology

    OpenAIRE

    Tirrell, David A.

    1988-01-01

    Polymer chemistry has a great deal to offer in the construction of synthetic liposomal membranes for use in biology and medicine. This chapter explores the preparation and properties of polymeric liposomes , with particular emphasis on the use of controlled polyelectrolyte adsorption to manipulate liposomal membrane properties.

  10. Protostellar accretion traced with chemistry

    DEFF Research Database (Denmark)

    Frimann, Søren; Jørgensen, Jes K.; Padoan, Paolo;

    2016-01-01

    used foranalysing the observations. Methods: Simple freeze-out andsublimation chemistry is added to the simulation, and syntheticC18O line cubes are created for a large number of simulatedprotostars. The spatial extent of C18O is measured for thesimulated protostars and compared directly to a sample of...

  11. Chemistry Teaching: Science or Alchemy?

    Science.gov (United States)

    Johnstone, A. H.

    1997-01-01

    Suggests that the development of good chemistry teaching and the pursuit of research have essentially the same structure. Similarities include the need for a clear focus, efficiency in time and effort, and a direction that is more often right than wrong. (DDR)

  12. Supramolecular chemistry and crystal engineering

    Indian Academy of Sciences (India)

    Ashwini Nangia

    2010-05-01

    Advances in supramolecular chemistry and crystal engineering reported from India within the last decade are highlighted in the categories of new intermolecular interactions, designed supramolecular architectures, network structures, multi-component host-guest systems, cocrystals, and polymorphs. Understanding self-assembly and crystallization through X-ray crystal structures is illustrated by two important prototypes - the large unit cell of elusive saccharin hydrate, Na16(sac)16 . 30H2O, which contains regular and irregular domains in the same structure, and by the Aufbau build up of zinc phosphate framework structures, e.g. ladder motif in [C3N2H12][Zn(HPO4)2] to layer structure in [C3N2H12][Zn2(HPO4)3] upon prolonged hydrothermal conditions. The pivotal role of accurate X-ray diffraction in supramolecular and structural studies is evident in many examples. Application of the bottomup approach to make powerful NLO and magnetic materials, design of efficient organogelators, and crystallization of novel pharmaceutical polymorphs and cocrystals show possible future directions for interdisciplinary research in chemistry with materials and pharmaceutical scientists. This article traces the evolution of supramolecular chemistry and crystal engineering starting from the early nineties and projects a center stage for chemistry in the natural sciences.

  13. Visualizing Chemistry: Investigations for Teachers.

    Science.gov (United States)

    Ealy, Julie B.; Ealy, James L., Jr.

    This book contains 101 investigations for chemistry classrooms. Topics include: (1) Physical Properties; (2) Reactions of Some Elements; (3) Reactions Involving Gases; (4) Energy Changes; (5) Solutions and Solubility; (6) Transition Metals and Complex Ions; (7) Kinetics and Equilibrium; (8) Acids and Bases; (9) Oxidation-Reduction; (10)…

  14. Radiation chemistry of ionic liquids

    International Nuclear Information System (INIS)

    Ionic liquids are expected as a replacement of processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiations and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. (author)

  15. A Comprehensive General Chemistry Demonstration

    Science.gov (United States)

    Sweeder, Ryan D.; Jeffery, Kathleen A.

    2013-01-01

    This article describes the use of a comprehensive demonstration suitable for a high school or first-year undergraduate introductory chemistry class. The demonstration involves placing a burning candle in a container adjacent to a beaker containing a basic solution with indicator. After adding a lid, the candle will extinguish and the produced…

  16. Plasma chemistry and organic synthesis

    Science.gov (United States)

    Tezuka, M.

    1980-01-01

    The characteristic features of chemical reactions using low temperature plasmas are described and differentiated from those seen in other reaction systems. A number of examples of applications of plasma chemistry to synthetic reactions are mentioned. The production of amino acids by discharge reactions in hydrocarbon-ammonia-water systems is discussed, and its implications for the origins of life are mentioned.

  17. Organic chemistry in Titan's atmosphere

    Science.gov (United States)

    Scattergood, T.

    1982-01-01

    Laboratory photochemical simulations and other types of chemical simulations are discussed. The chemistry of methane, which is the major known constituent of Titan's atmosphere was examined with stress on what can be learned from photochemistry and particle irradiation. The composition of dust that comprises the haze layer was determined. Isotope fractionation in planetary atmospheres is also discussed.

  18. BWR water chemistry impurity studies

    International Nuclear Information System (INIS)

    Laboratory studies were made on the effect of water impurities on environmental cracking in simulated BWR water of stainless steel, low alloy steel and nickel-base alloys. Constant elongation rate tensile (CERT) tests were run in simulated normal water chemistry (NWC), hydrogen water chemistry (HWC), or start-up environment. Sulfate, chloride and copper with chloride added to the water at levels of a fraction of a ppM were found to be extremely deleterious to all kinds of materials except Type 316 NG. Other detrimental impurities were fluoride, silica and some organic acids, although acetic acid was beneficial. Nitrate and carbon dioxide were fairly inoccuous. Corrosion fatigue and constant load tests on compact tension specimens were run in simulated normal BWR water chemistry (NWC) or hydrogen water chemistry (HWC), without impurities or with added sulfate or carbon dioxide. For sensitized Type 304 SS in NWC, 0.1 ppM sulfate increased crack propagation rates in constant load tests by up to a factor of 100, and in fatigue tests up to a factor of 10. Also, cracking in Type 316 nuclear grade SS and Alloy 600 was enhanced, but to a smaller degree. Carbon dioxide was less detrimental than sulfate. 3 figs., 4 tabs

  19. Simplified Model for Reburning Chemistry

    DEFF Research Database (Denmark)

    Glarborg, Peter; Hansen, Stine

    2010-01-01

    In solid fuel flames, reburn-type reactions are often important for the concentrations of NOx in the near-burner region. To be able to model the nitrogen chemistry in these flames, it is necessary to have an adequate model for volatile/NO interactions. Simple models consisting of global steps or...

  20. Computational Chemistry of Adhesive Bonds

    Science.gov (United States)

    Phillips, Donald H.

    1999-01-01

    This investigation is intended to determine the electrical mechanical, and chemical properties of adhesive bonds at the molecular level. The initial determinations will be followed by investigations of the effects of environmental effects on the chemistry and properties of the bond layer.

  1. IV. Health physics and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Garden, N.B.; Moyer, B.J.

    1948-05-24

    This report describes progress on the development of equipment and techniques to accomplish the goal of control and trapping of radioactive sustances. Emphasis is on simplicity reproducibiolity, and universal use. Also illustrated is the Health Chemistry Organization set-up of personnel.

  2. Diverse applications of radiation chemistry

    International Nuclear Information System (INIS)

    Radiation chemistry began as early radiotherapists needed a reliable and appropriate dosimeter. The iron sulphate dosimeter, using ferrous iron in sulphuric acid and oxidation by irradiation, was a nasty brew of chemicals but it was sensitive, reliable and conveniently had the same density as human tissue. Water irradiation chemistry studies were driven by the need to understand the fundamental processes in radiotherapy; to control the corrosion problems in the cooling/ heat exchange systems of nuclear reactors and to find stable solvents and reagents for use in spent fuel element processing. The electrical and mechanical stability of materials in high radiation fields stimulated the attention of radiation chemists to the study of defects in solids. The coupled use of radiation and Electron Spin Resonance (ESR) enabled the identity of defect structures to be probed. This research led to the development of the sensitive Thermoluminescent Dosimeters, TLD's and a technique for dating of archaeological pottery artefacts. Radiation chemistry in the area of medicine is very active with fundamental studies of the mechanism of DNA strand breakage and the development of radiation sensitisers and protectors for therapeutic purposes. The major area of polymer radiation chemistry is one which Australia commands great international respect

  3. Chemistry of the transactinide elements

    International Nuclear Information System (INIS)

    The synthesis and decay of the elements 104, 105 and 106 are described as well as the chemistry of the elements in the gaseous and liquid phase. The electron configurations of the ground state of the elements 105 and higher are described, as well as further chemical properties. (SR)

  4. Organometallic chemistry: A new metathesis

    Science.gov (United States)

    Hennessy, Elisabeth T.; Jacobsen, Eric N.

    2016-08-01

    Carbonyls and alkenes, two of the most common functional groups in organic chemistry, generally do not react with one another. Now, a simple Lewis acid has been shown to catalyse metathesis between alkenes and ketones in a new carbonyl olefination reaction.

  5. Quantum Nanobiology and Biophysical Chemistry

    DEFF Research Database (Denmark)

    2013-01-01

    An introduction was provided in the first issue by way of an Editorial to this special two issue volume of Current Physical Chemistry – “Quantum Nanobiology and Biophysical Chemistry” [1]. The Guest Editors would like to thank all the authors and referees who have contributed to this second issue...

  6. Chemistry without borders: An overview

    Science.gov (United States)

    As chemistry becomes more globalized, it is important for an organization to be interconnected and adaptable, and for an individual to keep up with changes and latest scientific findings and keep options open. Many of the challenges and the opportunities of globalization are in the areas of jobs, re...

  7. Structural Chemistry of Functional Materials

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ This innovative research group on structural chemistry of functional materials was approved by NSFC in 2005.Headed by Prof.HONG Maochun, the team consists of several young research scientists from the CAS Fujian Institute of Research on the Structures of Matter, including Profs CAO Rong, LU Canzhong, GUO Guocong, CHEN Zhongning, MAO Jianggao Mao and CHEN Ling.

  8. Green chemistry for chemical synthesis

    OpenAIRE

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.

  9. Green chemistry for chemical synthesis

    Science.gov (United States)

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign. PMID:18768813

  10. Some advances in atmospheric chemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the recent decade, researches have been carried out by our group on some aspects of atmospheric chemistry through field observation, mechanism analysis and model simulation. Here some main results on greenhouse gas (CH4, N2O) emission from Chinese agricultural fields, aerosol, global carbon cycle and ozone variation in surface laver over China are briefly reported.

  11. Teaching Techniques in Clinical Chemistry.

    Science.gov (United States)

    Wilson, Diane

    This master's thesis presents several instructional methods and techniques developed for each of eleven topics or subject areas in clinical chemistry: carbohydrate metabolism, lipid metabolism, diagnostic enzymology, endocrinology, toxicology, quality control, electrolytes, acid base balance, hepatic function, nonprotein nitrogenous compounds, and…

  12. Chemistry Perfumes Your Daily Life

    Science.gov (United States)

    Fortineau, Anne-Dominique

    2004-01-01

    A synopsis on the history of perfumery is presented, along with the various processes accessible for obtaining natural perfume constituents, and creation of synthetic chemicals. The important contribution of organic chemists in the invention of perfumes, aspects of fragrance chemistry, and general information on the perfume industry are…

  13. Chemistry of high temperature superconductors

    CERN Document Server

    1991-01-01

    This review volume contains the most up-to-date articles on the chemical aspects of high temperature oxide superconductors. These articles are written by some of the leading scientists in the field and includes a comprehensive list of references. This is an essential volume for researchers working in the fields of ceramics, materials science and chemistry.

  14. Protostellar accretion traced with chemistry

    DEFF Research Database (Denmark)

    Frimann, Søren; Jørgensen, Jes K.; Padoan, Paolo;

    2016-01-01

    methodology used for analysing the observations. Methods: Simple freeze-out and sublimation chemistry is added to the simulation, and synthetic C18O line cubes are created for a large number of simulated protostars. The spatial extent of C18O is measured for the simulated protostars, and compared directly to...

  15. Biosensors in clinical chemistry: An overview

    Directory of Open Access Journals (Sweden)

    Sathish Babu Murugaiyan

    2014-01-01

    Full Text Available Biosensors are small devices that employ biological/biochemical reactions for detecting target analytes. Basically, the device consists of a biocatalyst and a transducer. The biocatalyst may be a cell, tissue, enzyme or even an oligonucleotide. The transducers are mainly amperometric, potentiometric or optical. The classification of biosensors is based on (a the nature of the recognition event or (b the intimacy between the biocatalyst and the transducer. Bioaffinity and biocatalytic devices are examples for the former and the first, whereas second and third generation instruments are examples for the latter. Cell-based biosensors utilizing immobilized cells, tissues as also enzyme immunosensors and DNA biosensors find variegated uses in diagnostics. Enzyme nanoparticle-based biosensors make use of small particles in the nanometer scale and are currently making a mark in laboratory medicine. Nanotechnology can help in optimizing the diagnostic biochips, which would facilitate sensitive, rapid, accurate and precise bedside monitoring. Biosensors render themselves as capable diagnostic tools as they meet most of the above-mentioned criteria.

  16. Biosensors in clinical chemistry: An overview.

    Science.gov (United States)

    Murugaiyan, Sathish Babu; Ramasamy, Ramesh; Gopal, Niranjan; Kuzhandaivelu, V

    2014-01-01

    Biosensors are small devices that employ biological/biochemical reactions for detecting target analytes. Basically, the device consists of a biocatalyst and a transducer. The biocatalyst may be a cell, tissue, enzyme or even an oligonucleotide. The transducers are mainly amperometric, potentiometric or optical. The classification of biosensors is based on (a) the nature of the recognition event or (b) the intimacy between the biocatalyst and the transducer. Bioaffinity and biocatalytic devices are examples for the former and the first, whereas second and third generation instruments are examples for the latter. Cell-based biosensors utilizing immobilized cells, tissues as also enzyme immunosensors and DNA biosensors find variegated uses in diagnostics. Enzyme nanoparticle-based biosensors make use of small particles in the nanometer scale and are currently making a mark in laboratory medicine. Nanotechnology can help in optimizing the diagnostic biochips, which would facilitate sensitive, rapid, accurate and precise bedside monitoring. Biosensors render themselves as capable diagnostic tools as they meet most of the above-mentioned criteria. PMID:24627875

  17. Nitrogen Compounds in Radiation Chemistry

    International Nuclear Information System (INIS)

    Water radiolysis in presence of N2 is probably the topic the most controversy in the field of water radiolysis. It still exists a strong discrepancy between the different reports of ammonia formation by water radiolysis in presence of N2 and moreover in absence of oxygen there is no agreement on the formation or not of nitrogen oxide like NO2- and NO3-. These discrepancies come from multiple sources: - the complexity of the reaction mechanisms where nitrogen is involved - the experimental difficulties - and, the irradiation conditions. The aim of the workshop is to capitalize the knowledge needed to go further in simulations and understanding the problems caused (or not) by the presence of nitrogen / water in the environment of radioactive materials. Implications are evident in terms of corrosion, understanding of biological systems and atmospheric chemistry under radiation. Topics covered include experimental and theoretical approaches, application and fundamental researches: - Nitrate and Ammonia in radiation chemistry in nuclear cycle; - NOx in biological systems and atmospheric chemistry; - Formation of Nitrogen compounds in Nuclear installations; - Nitrogen in future power plant projects (Gen4, ITER...) and large particle accelerators. This document gathers the transparencies available for 7 of the presentations given at this workshop. These are: - H.E SIMS: 'Radiation Chemistry of Nitrogen Compounds in Nuclear Power Plant'; - G.R. DEY: 'Nitrogen Compounds Formation in the Radiolysis of Aqueous Solutions'; - C.E. VAUDEY et al.: 'Radiolytic corrosion of nuclear graphite studied with the dedicated gas irradiation cell of IPNL'; - J.L. BOUCHER: 'Roles and biosynthesis of NO in eukaryotes and prokaryotes'; - W.H. KOPPENOL: 'Chemistry of NOx'; - E. JANATA: 'Yield of OH in N2O saturated aqueous solution'; - V. DAUVOIS: 'Analytical strategy for the study of radiolysis gases'

  18. Some Exercises Reflecting Green Chemistry Concepts

    Science.gov (United States)

    Song, Yu-Min; Wang, Yong-Cheng; Geng, Zhi-Yuan

    2004-01-01

    Some exercises to introduce students to the concept of green chemistry are given. By doing these exercises, students develop an appreciation for the role of green chemistry on feedstock substitution, milder reaction conditions, reduced environmental exposure, and resource conservation.

  19. Problems in Quantum Chemistry and Spectroscopy

    DEFF Research Database (Denmark)

    Spanget-Larsen, Jens

    2015-01-01

    A collection of 22 introductory exercise problems for the course "Quantum Chemistry and Spectroscopy (QCS)".......A collection of 22 introductory exercise problems for the course "Quantum Chemistry and Spectroscopy (QCS)"....

  20. Outlook Bright for Computers in Chemistry.

    Science.gov (United States)

    Baum, Rudy M.

    1981-01-01

    Discusses the recent decision to close down the National Resource for Computation in Chemistry (NRCC), implications of that decision, and various alternatives in the field of computational chemistry. (CS)

  1. Process chemistry {ampersand} statistics quality assurance plan

    Energy Technology Data Exchange (ETDEWEB)

    Meznarich, H.K.

    1996-08-01

    This document provides quality assurance guidelines and quality control requirements for Process Chemistry and Statistics. This document is designed on the basis of Hanford Analytical Services Quality Assurance Plan (HASQAP) technical guidelines and is used for governing process chemistry activities.

  2. Environmental Chemistry in the High School Curriculum.

    Science.gov (United States)

    Stearns, Carole

    1988-01-01

    Discusses the incorporation of environmental chemistry topics into the traditional high school chemistry curriculum. Describes and provides lesson plans for the sulfur cycle and acid rain, and radioactivity and nuclear energy. Considers possible laboratory experiments. (CW)

  3. Supramolecular chemistry: Functional structures on the mesoscale

    OpenAIRE

    Nguyen, SonBinh T.; Gin, Douglas L.; Hupp, Joseph T.; Zhang, Xi

    2001-01-01

    Supramolecular chemistry deals with the chemistry and collective behavior of organized ensembles of molecules. In this so-called mesoscale regime, molecular building blocks are organized into longer-range order and higher-order functional structures via comparatively weak forces. As one of the modern frontiers in chemistry, supramolecular chemistry heralds many promises that range from biocompatible materials and biomimetic catalysts to sensors and nanoscale fabrication of electronic devices.

  4. Eleventh international symposium on radiopharmaceutical chemistry

    International Nuclear Information System (INIS)

    This document contains abstracts of papers which were presented at the Eleventh International Symposium on Radiopharmaceutical Chemistry. Sessions included: radiopharmaceuticals for the dopaminergic system, strategies for the production and use of labelled reactive small molecules, radiopharmaceuticals for measuring metabolism, radiopharmaceuticals for the serotonin and sigma receptor systems, labelled probes for molecular biology applications, radiopharmaceuticals for receptor systems, radiopharmaceuticals utilizing coordination chemistry, radiolabelled antibodies, radiolabelling methods for small molecules, analytical techniques in radiopharmaceutical chemistry, and analytical techniques in radiopharmaceutical chemistry

  5. Eleventh international symposium on radiopharmaceutical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This document contains abstracts of papers which were presented at the Eleventh International Symposium on Radiopharmaceutical Chemistry. Sessions included: radiopharmaceuticals for the dopaminergic system, strategies for the production and use of labelled reactive small molecules, radiopharmaceuticals for measuring metabolism, radiopharmaceuticals for the serotonin and sigma receptor systems, labelled probes for molecular biology applications, radiopharmaceuticals for receptor systems, radiopharmaceuticals utilizing coordination chemistry, radiolabelled antibodies, radiolabelling methods for small molecules, analytical techniques in radiopharmaceutical chemistry, and analytical techniques in radiopharmaceutical chemistry.

  6. New Earth, New Chemistry. Agenda for the Topsector Chemistry

    International Nuclear Information System (INIS)

    The Dutch Cabinet has appointed 9 top sectors in which the Netherlands holds a strong global position. One of these sectors is the chemical sector. The action agenda proposes two central ambitions for the long term: (1) In 2050 the Netherlands is globally known as the country with green chemistry; (2) In 2050 the Netherlands is in the global top 3 of producers of smart materials.

  7. One-world chemistry and systems thinking

    Science.gov (United States)

    Matlin, Stephen A.; Mehta, Goverdhan; Hopf, Henning; Krief, Alain

    2016-05-01

    The practice and overarching mission of chemistry need a major overhaul in order to be fit for purpose in the twenty-first century and beyond. The concept of 'one-world' chemistry takes a systems approach that brings together many factors, including ethics and sustainability, that are critical to the future role of chemistry.

  8. Undergraduate Chemistry Education: A Workshop Summary

    Science.gov (United States)

    Sawyer, Keegan; Alper, Joe

    2014-01-01

    "Undergraduate Chemistry Education" is the summary of a workshop convened in May 2013 by the Chemical Science Roundtable of the National Research Council to explore the current state of undergraduate chemistry education. Research and innovation in undergraduate chemistry education has been done for many years, and one goal of this…

  9. An Approach towards Teaching Green Chemistry Fundamentals

    Science.gov (United States)

    van Arnum, Susan D.

    2005-01-01

    A useful metrics system for the assessment of the environmental impact of chemical processes is utilized to illustrate several of the principles of green chemistry. The use of this metrics system in conjunction with laboratory experiments in green chemistry would provide for reinforcement in both the theory and practice of green chemistry.

  10. Greener Approaches to Undergraduate Chemistry Experiments.

    Science.gov (United States)

    Kirchhoff, Mary, Ed.; Ryan, Mary Ann, Ed.

    This laboratory manual introduces the idea of Green Chemistry, which is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. Instructional samples are included to help teachers integrate green chemistry into the college chemistry curriculum. Each laboratory includes: (1) a…

  11. A Discovery Chemistry Experiment on Buffers

    Science.gov (United States)

    Kulevich, Suzanne E.; Herrick, Richard S.; Mills, Kenneth V.

    2014-01-01

    The Holy Cross Chemistry Department has designed and implemented an experiment on buffers as part of our Discovery Chemistry curriculum. The pedagogical philosophy of Discovery Chemistry is to make the laboratory the focal point of learning for students in their first two years of undergraduate instruction. We first pose questions in prelaboratory…

  12. Reaction-Map of Organic Chemistry

    Science.gov (United States)

    Murov, Steven

    2007-01-01

    The Reaction-Map of Organic Chemistry lists all the most commonly studied reactions in organic chemistry on one page. The discussed Reaction-Map will act as another learning aide for the students, making the study of organic chemistry much easier.

  13. 42 CFR 493.929 - Chemistry.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Chemistry. 493.929 Section 493.929 Public Health... Proficiency Testing Programs by Specialty and Subspecialty § 493.929 Chemistry. The subspecialties under the specialty of chemistry for which a proficiency testing program may offer proficiency testing are...

  14. 42 CFR 493.931 - Routine chemistry.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Routine chemistry. 493.931 Section 493.931 Public... Proficiency Testing Programs by Specialty and Subspecialty § 493.931 Routine chemistry. (a) Program content and frequency of challenge. To be approved for proficiency testing for routine chemistry, a...

  15. Steroidal ribbons for supramolecular and medicinal chemistry

    Czech Academy of Sciences Publication Activity Database

    Černý, Ivan; Pouzar, Vladimír; Drašar, P.

    Tafila : Tafila Technical University, 2007 - (Ibril, I.). IL21 [Petra International Chemistry Conference and Transmediteranean Colloquium on Heterocyclic Chemistry. 25.06.2007-28.06.2007, Tafila] Institutional research plan: CEZ:AV0Z40550506 Keywords : steroids * oligomers * amides Subject RIV: CC - Organic Chemistry

  16. Let Environmental Chemistry Enrich Your Curriculum.

    Science.gov (United States)

    Parravano, Carlo

    1988-01-01

    Describes a one-semester course in environmental chemistry for students who have had a full year of introductory level chemistry. Illustrates how material from this upper-level course was integrated into a general chemistry course. Examples of content are provided. (CW)

  17. Introducing Green Chemistry in Teaching and Research.

    Science.gov (United States)

    Collins, Terrence J.

    1995-01-01

    Describes key elements for the research and teaching components of green chemistry, an environmentally friendly approach to chemistry. Presents an outline of an introductory course to green chemistry and other efforts at Carnegie Mellon University to incorporate the environment in a fertile manner into teaching. (JRH)

  18. AECL research programs in systems chemistry

    International Nuclear Information System (INIS)

    Research programs in Systems Chemistry are aimed at preserving the integrity of the many working systems in CANDU reactors and at minimizing chemistry-induced problems such as radiation field growth or fouling of surfaces. The topics of main concern are the chemistry and corrosion of steam generators, for it is in this general area that the potential for serious problems is very real

  19. Supplemental Instruction in Physical Chemistry I

    Science.gov (United States)

    Toby, Ellen; Scott, Timothy P.; Migl, David; Kolodzeji, Elizabeth

    2016-01-01

    Physical chemistry I at Texas A&M University is an upper division course requiring mathematical and analytical skills. As such, this course poses a major problem for many Chemistry, Engineering, Biochemistry and Genetics majors. Comparisons between participants and non-participants in Supplemental Instruction for physical chemistry were made…

  20. Diversity and Periodicity: An Inorganic Chemistry Module.

    Science.gov (United States)

    Huheey, James

    This book is one in a series of Interdisciplinary Approaches to Chemistry (IAC) designed to help students discover that chemistry is a lively science and actively used to pursue solutions to the important problems of today. It is expected for students to see how chemistry takes place continuously all around and to readily understand the daily…

  1. The Journal of Kitchen Chemistry: A Tool for Instructing the Preparation of a Chemistry Journal Article

    Science.gov (United States)

    Meyers, Jonathan K.; LeBaron, Tyler W.; Collins, David C.

    2014-01-01

    Writing assignments are typically incorporated into chemistry courses in an attempt to enhance the learning of chemistry or to teach technical writing to chemistry majors. This work addresses the development of chemistry-major writing skills by focusing on the rigorous guidelines and conventions associated with the preparation of a journal…

  2. Atmospheric Chemistry Over Southern Africa

    Science.gov (United States)

    Gatebe, Charles K.; Levy, Robert C.; Thompson, Anne M.

    2011-01-01

    During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semi-permanent atmosphere gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s, and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite-derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field

  3. Abstracts of the 26. Brazilian Congress on Chemistry

    International Nuclear Information System (INIS)

    It is presented the short communications of papers presented at the 26. Brazilian Congress on Chemistry, of nuclear interest. The papers are classified in four areas: isotope chemistry, organic chemistry, inorganic chemistry and physico-chemical. (E.G.)

  4. Chemistry Of Atmospheric Brown Carbon

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2015-05-27

    Organic carbon (OC) accounts for a large fraction of atmospheric aerosol and has profound effects on air quality, atmospheric chemistry and climate forcing. Molecular composition of the OC and its evolution during common processes of atmospheric aging have been a subject of extensive research over the last decade (see reviews of Ervens et al.,1 Hallquist et al.,2 Herckes et al.,3 Carlton et al.,4 Kroll and Seinfeld,5 Rudich et al.,6 and Kanakidou et al.7). Even though many fundamental advances have been reported in these studies, our understanding of the climate-related properties of atmospheric OC is still incomplete and the specific ways in which OC impacts atmospheric environment and climate forcing are just beginning to be understood. This review covers one topic of particular interest in this area –environmental chemistry of light-absorbing aerosol OC and its impact on radiative forcing.

  5. Radiation applications of physical chemistry

    International Nuclear Information System (INIS)

    Many chemical energy problems have a physical chemistry nature connected with chemical kinetics and thermodynamics. In our country, the development in this field is associated with the name N.N. Semenov, who was involved in a large number of fundamental and applied physical chemistry problems.Energy development during the last decades created or sharpened new problems. Our new Institute, the Institute of Energy problems of Chemical Physics, USSR Academy of Sciences, is dealing with some of them. The present article is an overview of our work on radiation applications. Examples of the use of radiation in power industry (such as coal gasification), tire production, mechanical joints, metal powder production and sterilization of pharmaceutical products are given. Methods and problems involved in these applications are discussed and the great potential for vast utilization is demonstrated. (authors)

  6. Radiation chemistry and the environment

    International Nuclear Information System (INIS)

    The rather strong and many-sided pollution of the environment (atmosphere, water resources, soil) as a consequence of human activities is summarized. The solution of the arised problems by application of radiation chemistry methods and the utilization of modern environmentally ''clean'' and economical technologies, founded on electron beam processing, are mentioned. Some basic environmental problems and their solution are briefly discussed: i) Removal of CO2 from flue gases and its radiation induced utilization. ii) Principals for degradation of aqueous pollutants by electron beam processing in the presence of ozone (synergistic effect). The radiation chemistry as a modern and manifold discipline with very broad applications can also essentially contribute in the conservation of the environment

  7. Radiation chemistry and its applications

    International Nuclear Information System (INIS)

    In recent years considerable progress has been made in understanding the fundamental chemical reactions that occur when materials are irradiated. This has followed from the development of new techniques for studying these reactions. The International Atomic Energy Agency held a Panel on Radiation Chemistry in Vienna on 17-21 April 1967, to review the current status of various sources, new techniques in radiation chemistry, and their applications. The main sources mentioned by the Panel were isotope sources, electron accelerators, and chemonuclear reactors. Among the basic techniques discussed were pulsed radiolysis, flash photolysis, fast ESR methods, irradiation at liquid helium temperatures, electric discharge methods and far ultra-violet methods. Interesting industrial applications were discussed, such as the development of wood-plastic combinations, and a paper was given on the curing of paints and thin films Refs, figs and tabs

  8. Amphoteric Aqueous Hafnium Cluster Chemistry.

    Science.gov (United States)

    Goberna-Ferrón, Sara; Park, Deok-Hie; Amador, Jenn M; Keszler, Douglas A; Nyman, May

    2016-05-17

    Selective dissolution of hafnium-peroxo-sulfate films in aqueous tetramethylammonium hydroxide enables extreme UV lithographic patterning of sub-10 nm HfO2 structures. Hafnium speciation under these basic conditions (pH>10), however, is unknown, as studies of hafnium aqueous chemistry have been limited to acid. Here, we report synthesis, crystal growth, and structural characterization of the first polynuclear hydroxo hafnium cluster isolated from base, [TMA]6 [Hf6 (μ-O2 )6 (μ-OH)6 (OH)12 ]⋅38 H2 O. The solution behavior of the cluster, including supramolecular assembly via hydrogen bonding is detailed via small-angle X-ray scattering (SAXS) and electrospray ionization mass spectrometry (ESI-MS). The study opens a new chapter in the aqueous chemistry of hafnium, exemplifying the concept of amphoteric clusters and informing a critical process in single-digit-nm lithography. PMID:27094575

  9. Chemistry and metallurgy of plutonium

    International Nuclear Information System (INIS)

    Plutonium is a strategic element with unique chemistry and metallurgy. It has five valence states with close redox potentials and many of them coexist in solutions. It is a hard Lewis acid and forms strong complexes with hard Lewis bases. Its redox and complexing characteristics are useful in its separation and analytical chemistry. Plutonium metal has several allotropic forms even though its melting point is only 639.5℃. It is a metal with very high density and one of the few metals which shrinks on heating. It holds promise of abundant nuclear energy, but also has potential for being diverted towards nuclear explosive devices. This paper is a brief compilation from available literature. (author)

  10. Actinide chemistry in ionic liquids.

    Science.gov (United States)

    Takao, Koichiro; Bell, Thomas James; Ikeda, Yasuhisa

    2013-04-01

    This Forum Article provides an overview of the reported studies on the actinide chemistry in ionic liquids (ILs) with a particular focus on several fundamental chemical aspects: (i) complex formation, (ii) electrochemistry, and (iii) extraction behavior. The majority of investigations have been dedicated to uranium, especially for the 6+ oxidation state (UO2(2+)), because the chemistry of uranium in ordinary solvents has been well investigated and uranium is the most abundant element in the actual nuclear fuel cycles. Other actinides such as thorium, neptunium, plutonium, americium, and curiumm, although less studied, are also of importance in fully understanding the nuclear fuel engineering process and the safe geological disposal of radioactive wastes. PMID:22873132

  11. Concept Maps in Chemistry Education

    Science.gov (United States)

    Regis, Alberto; Albertazzi, Pier Giorgio; Roletto, Ezio

    1996-11-01

    This article presents and illustrates a proposed application of concept maps in chemistry teaching in high schools. The students were provided with the "concept lables" necessary for map building in three different ways. The analysis of the students' maps at different stages of the learning process led to the recognition of the three types of cognitive events which seem to correspond to the same number of restructuring stages in the conceptual organization. This can enable the teacher to characterize the changes produced in the learners' conceptions by teaching / learning activities. Three examples of the use of concept maps in chemistry teaching are reported and discussed with reference to: atomic structure, oxidation-reduction and thermodynamics.

  12. Chemistry-nuclear chemistry division. Progress report, October 1979-September 1980

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R.R. (comp.)

    1981-05-01

    This report presents the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, element migration and fixation, inorganic chemistry, isotope separation and analysis, atomic and molecular collisions, molecular spectroscopy, muonic x rays, nuclear cosmochemistry, nuclear structure and reactions, radiochemical separations, theoretical chemistry, and unclassified weapons research.

  13. Chemistry-nuclear chemistry division. Progress report, October 1979-September 1980

    International Nuclear Information System (INIS)

    This report presents the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, element migration and fixation, inorganic chemistry, isotope separation and analysis, atomic and molecular collisions, molecular spectroscopy, muonic x rays, nuclear cosmochemistry, nuclear structure and reactions, radiochemical separations, theoretical chemistry, and unclassified weapons research

  14. IN-PACKAGE CHEMISTRY ABSTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    E. Thomas

    2005-07-14

    This report was developed in accordance with the requirements in ''Technical Work Plan for Postclosure Waste Form Modeling'' (BSC 2005 [DIRS 173246]). The purpose of the in-package chemistry model is to predict the bulk chemistry inside of a breached waste package and to provide simplified expressions of that chemistry as a function of time after breach to Total Systems Performance Assessment for the License Application (TSPA-LA). The scope of this report is to describe the development and validation of the in-package chemistry model. The in-package model is a combination of two models, a batch reactor model, which uses the EQ3/6 geochemistry-modeling tool, and a surface complexation model, which is applied to the results of the batch reactor model. The batch reactor model considers chemical interactions of water with the waste package materials, and the waste form for commercial spent nuclear fuel (CSNF) waste packages and codisposed (CDSP) waste packages containing high-level waste glass (HLWG) and DOE spent fuel. The surface complexation model includes the impact of fluid-surface interactions (i.e., surface complexation) on the resulting fluid composition. The model examines two types of water influx: (1) the condensation of water vapor diffusing into the waste package, and (2) seepage water entering the waste package as a liquid from the drift. (1) Vapor-Influx Case: The condensation of vapor onto the waste package internals is simulated as pure H{sub 2}O and enters at a rate determined by the water vapor pressure for representative temperature and relative humidity conditions. (2) Liquid-Influx Case: The water entering a waste package from the drift is simulated as typical groundwater and enters at a rate determined by the amount of seepage available to flow through openings in a breached waste package.

  15. CHRONOLOGICAL INVENTORY OF CHEMISTRY TEACHING

    OpenAIRE

    Laxman S. Bhattar; SWAMINATH L.BHATTAR

    2013-01-01

    The Chronological Research of Chemistry teaching in the science education isinvented by the following pioneer philosophers and they developed the skills abilitieswhich is remarked by the Greek philosophers are socrates and plato (in 116 to 127 BC)given an idea an naturalistic and conceptual thoughts and highlights on water. Chinaphilosophers (365 to 427 BC) Taoism made pioneer of Alchemy used in medicines andtranslation preparation of Au (Gold). Epicurea (341 to 371 to 400 BC) developed kinet...

  16. SUSTAINABLE CHEMISTRY FOR SUSTAINABLE INDUSTRY

    OpenAIRE

    RIZZUTO G.; BUCELLI F.; M. Sciaccaluga; AVATANEO O.

    2015-01-01

    Foundry Alfe Chem is an industrial reality working in the field of lubrication and chemical auxiliaries for industrial processes, which falls within the framework of the emerging and increasingly important «green chemistry». The goal of the company is to develop products that are more environmentally friendly by using raw materials from renewable sources; specifically, Foundry Alfe Chem has a program of self-sustainability that contemplates, for the foreseeable future, the direct production o...

  17. HISTORICAL DEVELOPMENTS IN WOOD CHEMISTRY

    OpenAIRE

    YOUNG, Raymond A.

    2009-01-01

    Wood are one of the most important raw material source for forest products industry. Due to technological developments, researchers in the area of wood chemistry have been showing increased interest in the benefits of utilization wood based materials alone or together as an alternative lignocellulosic fiber sources for forest products industry. However, utilization of woody matrials more efficiently and conservation natural resources have been paid special attention. For that reason...

  18. Wood products and green chemistry

    OpenAIRE

    Pizzi, Antonio

    2016-01-01

    Key message Green chemistry for and from wood has developed numerous industrial products, namely biosourced, green wood adhesives and preservatives, foams, composite matrices, laminates, hard and flexible plastics, flexible films, and abrasive grinding discs, and their number is still growing.IntroductionThis review addresses (1) the elimination of toxic aldehydes from the most common wood panel adhesive, the one based on urea, itself a natural product, (2) biosourced adhesives derived from w...

  19. Laser ablation in analytical chemistry.

    Science.gov (United States)

    Russo, Richard E; Mao, Xianglei; Gonzalez, Jhanis J; Zorba, Vassilia; Yoo, Jong

    2013-07-01

    In 2002, we wrote an Analytical Chemistry feature article describing the Physics of Laser Ablation in Microchemical Analysis. In line with the theme of the 2002 article, this manuscript discusses current issues in fundamental research, applications based on detecting photons at the ablation site (LIBS and LAMIS) and by collecting particles for excitation in a secondary source (ICP), and directions for the technology. PMID:23614661

  20. Handbook of computational quantum chemistry

    CERN Document Server

    Cook, David B

    2005-01-01

    Quantum chemistry forms the basis of molecular modeling, a tool widely used to obtain important chemical information and visual images of molecular systems. Recent advances in computing have resulted in considerable developments in molecular modeling, and these developments have led to significant achievements in the design and synthesis of drugs and catalysts. This comprehensive text provides upper-level undergraduates and graduate students with an introduction to the implementation of quantum ideas in molecular modeling, exploring practical applications alongside theoretical explanations.Wri

  1. Abiotic and prebiotic phosphorus chemistry

    OpenAIRE

    Micheletti, Gabriele

    2011-01-01

    The chief obstacle to understand the metabolic origin of life or RNA-based life is to identify a plausible mechanism for overcoming the clutter wrought by abiotic chemistry. Probably trough simple abiotic and then prebiotic reactions we could arrive to simple pre-RNA molecules. Here we report a possible preibiotic synthesis for heterocyclic compounds, and a self-assembling process of adenosine phosphates a constituent of RNA. In these processes we use a simple and prebiotic phosphorus cyc...

  2. Analytical chemistry of nuclear materials

    International Nuclear Information System (INIS)

    The second panel on the Analytical Chemistry of Nuclear Materials was organized for two purposes: first, to advise the Seibersdorf Laboratory of the Agency on its future programme, and second, to review the results of the Second International Comparison of routine analysis of trace impurities in uranium and also the action taken as a result of the recommendations of the first panel in 1962. Refs, figs and tabs

  3. Surface chemistry in photodissociation regions

    Science.gov (United States)

    Esplugues, G. B.; Cazaux, S.; Meijerink, R.; Spaans, M.; Caselli, P.

    2016-06-01

    Context. The presence of dust can strongly affect the chemical composition of the interstellar medium. We model the chemistry in photodissociation regions (PDRs) using both gas-phase and dust-phase chemical reactions. Aims: Our aim is to determine the chemical compositions of the interstellar medium (gas/dust/ice) in regions with distinct (molecular) gas densities that are exposed to radiation fields with different intensities. Methods: We have significantly improved the Meijerink PDR code by including 3050 new gas-phase chemical reactions and also by implementing surface chemistry. In particular, we have included 117 chemical reactions occurring on grain surfaces covering different processes, such as adsorption, thermal desorption, chemical desorption, two-body reactions, photo processes, and cosmic-ray processes on dust grains. Results: We obtain abundances for different gas and solid species as a function of visual extinction, depending on the density and radiation field. We also analyse the rates of the formation of CO2 and H2O ices in different environments. In addition, we study how chemistry is affected by the presence/absence of ice mantles (bare dust or icy dust) and the impact of considering different desorption probabilities. Conclusions: The type of substrate (bare dust or icy dust) and the probability of desorption can significantly alter the chemistry occurring on grain surfaces, leading to differences of several orders of magnitude in the abundances of gas-phase species, such as CO, H2CO, and CH3OH. The type of substrate, together with the density and intensity of the radiation field, also determine the threshold extinction to form ices of CO2 and H2O. We also conclude that H2CO and CH3OH are mainly released into the gas phase of low, far-ultraviolet illuminated PDRs through chemical desorption upon two-body surface reactions, rather than through photodesorption.

  4. GREEN CHEMISTRY: NEW CHEMICAL PHILOSOPHY

    OpenAIRE

    Tykhomirova, F. A.

    2015-01-01

    The review deals with the principles and guidelines of “Green chemistry” in comparison with the philosophy of nanotechnology. Modern philosophy and methodology of science research focus is on the process of the growth of scientific knowledge. Modern chemistry is complex, hierarchical, multilevel and multidimensional system. Philosophy of nanotechnology relies heavily on the value of scientism and the idea of domination of man over nature , there is an apology of human intervention in nature. ...

  5. IN-PACKAGE CHEMISTRY ABSTRACTION

    International Nuclear Information System (INIS)

    This report was developed in accordance with the requirements in ''Technical Work Plan for Postclosure Waste Form Modeling'' (BSC 2005 [DIRS 173246]). The purpose of the in-package chemistry model is to predict the bulk chemistry inside of a breached waste package and to provide simplified expressions of that chemistry as a function of time after breach to Total Systems Performance Assessment for the License Application (TSPA-LA). The scope of this report is to describe the development and validation of the in-package chemistry model. The in-package model is a combination of two models, a batch reactor model, which uses the EQ3/6 geochemistry-modeling tool, and a surface complexation model, which is applied to the results of the batch reactor model. The batch reactor model considers chemical interactions of water with the waste package materials, and the waste form for commercial spent nuclear fuel (CSNF) waste packages and codisposed (CDSP) waste packages containing high-level waste glass (HLWG) and DOE spent fuel. The surface complexation model includes the impact of fluid-surface interactions (i.e., surface complexation) on the resulting fluid composition. The model examines two types of water influx: (1) the condensation of water vapor diffusing into the waste package, and (2) seepage water entering the waste package as a liquid from the drift. (1) Vapor-Influx Case: The condensation of vapor onto the waste package internals is simulated as pure H2O and enters at a rate determined by the water vapor pressure for representative temperature and relative humidity conditions. (2) Liquid-Influx Case: The water entering a waste package from the drift is simulated as typical groundwater and enters at a rate determined by the amount of seepage available to flow through openings in a breached waste package

  6. Solid state chemistry and its applications

    CERN Document Server

    West, Anthony R

    2013-01-01

    Solid State Chemistry and its Applications, 2nd Edition: Student Edition is an extensive update and sequel to the bestselling textbook Basic Solid State Chemistry, the classic text for undergraduate teaching in solid state chemistry worldwide. Solid state chemistry lies at the heart of many significant scientific advances from recent decades, including the discovery of high-temperature superconductors, new forms of carbon and countless other developments in the synthesis, characterisation and applications of inorganic materials. Looking forward, solid state chemistry will be crucial for the

  7. PWR secondary water chemistry guidelines: Revision 3

    International Nuclear Information System (INIS)

    An effective, state-of-the art secondary water chemistry control program is essential to maximize the availability and operating life of major PWR components. Furthermore, the costs related to maintaining secondary water chemistry will likely be less than the repair or replacement of steam generators or large turbine rotors, with resulting outages taken into account. The revised PWR secondary water chemistry guidelines in this report represent the latest field and laboratory data on steam generator corrosion phenomena. This document supersedes Interim PWR Secondary Water Chemistry Recommendations for IGA/SCC Control (EPRI report TR-101230) as well as PWR Secondary Water Chemistry Guidelines--Revision 2 (NP-6239)

  8. The slow birth of green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Amato, I.

    1993-03-12

    Mainstream chemistry is beginning to look at environmental chemistry as an important solution to environmental problems. This can include research into developing cleaner-burning liquid fuels, cleaning up oil spills, or developing better process methods which engender less pollution, as opposed to previous practices of detecting pollutants without preventing their release to begin with. This article discusses the progress of this chemistry discipline, describes some of the ongoing research, and describes the future for environmental chemistry. An impetus for future growth will be generational change, as young scientists in training are beginning to push faculities into creating programs for environmental chemistry.

  9. Atmospheric chemistry in volcanic plumes.

    Science.gov (United States)

    von Glasow, Roland

    2010-04-13

    Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and heterogeneous reactions on aerosol particles that have previously been unexplored for this type of volcanic plumes. Key features of these measurements can be reproduced by numerical models such as the one employed in this study. The model shows sustained high levels of reactive bromine in the plume, leading to extensive ozone destruction, that, depending on plume dispersal, can be maintained for several days. The very high concentrations of sulfur dioxide in the volcanic plume reduces the lifetime of the OH radical drastically, so that it is virtually absent in the volcanic plume. This would imply an increased lifetime of methane in volcanic plumes, unless reactive chlorine chemistry in the plume is strong enough to offset the lack of OH chemistry. A further effect of bromine chemistry in addition to ozone destruction shown by the model studies presented here, is the oxidation of mercury. This relates to mercury that has been coemitted with bromine from the volcano but also to background atmospheric mercury. The rapid oxidation of mercury implies a drastically reduced atmospheric lifetime of mercury so that the contribution of volcanic mercury to the atmospheric background might be less than previously thought. However, the implications, especially health and environmental effects due to deposition, might be substantial and warrant further studies, especially field measurements to test this hypothesis. PMID:20368458

  10. AMS radiocarbon chemistry at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, G. [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia). Physics Division

    1999-11-01

    The purpose of this paper is to demystify the `black box` of AMS chemistry. For many, a sample is sent and eventually a date is received. Little is known of what happens to the sample beyond that it is treated chemically and then measured in the tandem accelerator. In this overview I will discuss the fate of your radiocarbon samples once they have arrived here at ANSTO with a focus on the chemistry. The AMS measurement of radiocarbon samples has been discussed previously (Lawson 1999). There are three main aims when it comes to the chemistry: 1) to remove extraneous carbon, ie contamination, 2) to convert the carbon to a form suitable for measurement in the tandem accelerator and 3) not to contaminate the sample while doing 1 and 2. Before measurement the sample goes through a number of distinct stages, these being registration, pretreatment, carbon extraction, graphitisation and pressing. Of these I am going to deal mainly with the pretreatment stage, as it is at this stage that contamination is removed for which the accuracy of the final measurement is dependant 12 refs.

  11. Department of Nuclear Physical Chemistry

    International Nuclear Information System (INIS)

    The research program at the Department of Nuclear Physical Chemistry of the Niewodniczanski Institute of Nuclear Physics is described. The Department consist of three laboratories. First - Laboratory of Physical Chemistry of Separation Processes on which the activity is concentrated on separation of radioactive isotopes from particle bombarded target. The main interest is production and separation of neutron deficient isotopes for medical diagnostic and therapy. The investigation program includes measurements of nuclear reaction cross sections,, band resolution technique, preparation of radioactive sources, detection of non-radioactive trace elements. An independent project on desulphurization of flue gases is also carried out in the Laboratory. In the second one - Laboratory of Chemistry and Radiochemistry - the systematic studies of physicochemical properties of transition elements in solutions are carried out. The results of the performed experiments were used for the elaboration of new rapid and selective methods for various elements. Some of these results have been applied for separation of trans actinide elements at U-400 cyclotron of JINR Dubna. The third one laboratory - Environmental Radioactivity Laboratory -conducts continuous monitoring of radioactivity contamination of atmosphere. The investigation of different radionuclides concentration in natural environment, mainly in the forest had been carried out. (author)

  12. AMS radiocarbon chemistry at ANSTO

    International Nuclear Information System (INIS)

    The purpose of this paper is to demystify the 'black box' of AMS chemistry. For many, a sample is sent and eventually a date is received. Little is known of what happens to the sample beyond that it is treated chemically and then measured in the tandem accelerator. In this overview I will discuss the fate of your radiocarbon samples once they have arrived here at ANSTO with a focus on the chemistry. The AMS measurement of radiocarbon samples has been discussed previously (Lawson 1999). There are three main aims when it comes to the chemistry: 1) to remove extraneous carbon, ie contamination, 2) to convert the carbon to a form suitable for measurement in the tandem accelerator and 3) not to contaminate the sample while doing 1 and 2. Before measurement the sample goes through a number of distinct stages, these being registration, pretreatment, carbon extraction, graphitisation and pressing. Of these I am going to deal mainly with the pretreatment stage, as it is at this stage that contamination is removed for which the accuracy of the final measurement is dependant

  13. Green chemistry; La chimie verte

    Energy Technology Data Exchange (ETDEWEB)

    Colonna, P. [Institut National de la Recherche Agronomique, Dept. Caracterisation et Elaboration des Produits, 78 - Versailles (France)

    2006-07-01

    The depletion of world fossil fuel reserves and the involvement of greenhouse gases in the global warming has led to change the industrial and energy policies of most developed countries. The goal is now to reserve petroleum to the uses where it cannot be substituted, to implement renewable raw materials obtained from plants cultivation, and to consider the biodegradability of molecules and of manufactured objects by integrating the lifetime concept in their expected cycle of use. The green chemistry includes the design, development and elaboration of chemical products and processes with the aim of reducing or eliminating the use and generation of harmful compounds for the health and the environment, by adapting the present day operation modes of the chemical industry to the larger framework of the sustainable development. In addition to biofuels, this book reviews the applications of green chemistry in the different industrial processes in concern. Part 1 presents the diversity of the molecules coming from renewable carbon, in particular lignocellulose and the biotechnological processes. Part 2 is devoted to materials and treats of the overall available technological solutions. Part 3 focusses on functional molecules and chemical intermediates, in particular in sugar- and fats-chemistry. Part 4 treats of biofuels under the aspects of their production and use in today's technologies. The last part deals with the global approaches at the environmental and agricultural levels. (J.S.)

  14. Peer Mentoring in the General Chemistry and Organic Chemistry Laboratories. The Pinacol Rearrangement: An Exercise in NMR and IR Spectroscopy for General Chemistry and Organic Chemistry Laboratories

    Science.gov (United States)

    Arrington, Caleb A.; Hill, Jameica B.; Radfar, Ramin; Whisnant, David M.; Bass, Charles G.

    2008-02-01

    This article describes a discovery experiment for general chemistry and organic chemistry labs. Although the pinacol rearrangement has been employed in undergraduate organic laboratories before, in this application organic chemistry students act as mentors to students of general chemistry. Students work together using distillation—a new technique for the general chemistry students and a basic one for the organic students—to isolate an unknown compound. Then, using spectroscopy (IR and NMR), the students collaborate to determine the structure of the product of the reaction. This application of a standard experiment allows general chemistry students to gain exposure to modern spectroscopic instrumentation and to enhance their problem-solving skills. Organic chemistry students improve their understandings of laboratory techniques and spectroscopic interpretation by acting as the resident experts for the team.

  15. New trends and developments in radiation chemistry

    International Nuclear Information System (INIS)

    Radiation chemistry is a branch of chemistry that studies chemical transformations in materials exposed to high-energy radiations. It uses radiation as the initiator of chemical reactions. Practical applications of radiation chemistry today extend to many fields, including health care, food and agriculture, manufacturing, industrial pollution abatement, biotechnology and telecommunications. The important advantage of radiation chemistry lies in its ability to be used to produce, and study, almost any reactive atomic and molecular species playing a part in chemical reactions, synthesis, industrial processes, or in biological systems. The techniques are applicable to gaseous, liquid, solid, and heterogeneous systems. By combining different techniques of radiation chemistry with analytical chemistry, the reaction mechanism and kinetics of chemical reactions are studied. In November 1988 in Bologna, Italy, the IAEA convened an advisory group meeting to assess new trends and developments in radiation chemistry. The present publication includes most of the contributions presented at the meeting. Refs, figs and tabs

  16. In-Package Chemistry Abstraction

    International Nuclear Information System (INIS)

    This report was developed in accordance with the requirements in ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of the in-package chemistry model is to predict the bulk chemistry inside of a breached waste package and to provide simplified expressions of that chemistry as function of time after breach to Total Systems Performance Assessment for the License Application (TSPA-LA). The scope of this report is to describe the development and validation of the in-package chemistry model. The in-package model is a combination of two models, a batch reactor model that uses the EQ3/6 geochemistry-modeling tool, and a surface complexation model that is applied to the results of the batch reactor model. The batch reactor model considers chemical interactions of water with the waste package materials and the waste form for commercial spent nuclear fuel (CSNF) waste packages and codisposed waste packages that contain both high-level waste glass (HLWG) and DOE spent fuel. The surface complexation model includes the impact of fluid-surface interactions (i.e., surface complexation) on the resulting fluid composition. The model examines two types of water influx: (1) the condensation of water vapor that diffuses into the waste package, and (2) seepage water that enters the waste package from the drift as a liquid. (1) Vapor Influx Case: The condensation of vapor onto the waste package internals is simulated as pure H2O and enters at a rate determined by the water vapor pressure for representative temperature and relative humidity conditions. (2) Water Influx Case: The water entering a waste package from the drift is simulated as typical groundwater and enters at a rate determined by the amount of seepage available to flow through openings in a breached waste package. TSPA-LA uses the vapor influx case for the nominal scenario for simulations where the waste package has been

  17. In-Package Chemistry Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    E. Thomas

    2004-11-09

    This report was developed in accordance with the requirements in ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of the in-package chemistry model is to predict the bulk chemistry inside of a breached waste package and to provide simplified expressions of that chemistry as function of time after breach to Total Systems Performance Assessment for the License Application (TSPA-LA). The scope of this report is to describe the development and validation of the in-package chemistry model. The in-package model is a combination of two models, a batch reactor model that uses the EQ3/6 geochemistry-modeling tool, and a surface complexation model that is applied to the results of the batch reactor model. The batch reactor model considers chemical interactions of water with the waste package materials and the waste form for commercial spent nuclear fuel (CSNF) waste packages and codisposed waste packages that contain both high-level waste glass (HLWG) and DOE spent fuel. The surface complexation model includes the impact of fluid-surface interactions (i.e., surface complexation) on the resulting fluid composition. The model examines two types of water influx: (1) the condensation of water vapor that diffuses into the waste package, and (2) seepage water that enters the waste package from the drift as a liquid. (1) Vapor Influx Case: The condensation of vapor onto the waste package internals is simulated as pure H2O and enters at a rate determined by the water vapor pressure for representative temperature and relative humidity conditions. (2) Water Influx Case: The water entering a waste package from the drift is simulated as typical groundwater and enters at a rate determined by the amount of seepage available to flow through openings in a breached waste package. TSPA-LA uses the vapor influx case for the nominal scenario for simulations where the waste

  18. APPLICATIONS OF GREEN CHEMISTRY IN SUSTAINABLE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Suresh D. Dhage

    2013-07-01

    Full Text Available Chemistry is really very helpful to us as its applications are used worldwide for several purposes. We cannot really imagine a world without chemistry and its applications such as medicines. However, we should now concentrate on green chemistry or sustainable chemistry, which refers to reducing or stopping the damage done to the environment around us. Hence, green chemistry could include anything from reducing waste to even disposing of waste in the correct manner. Another way to save the environment through sustainable chemistry is to make use of renewable food stocks. Yet another good move is to make use of catalysts in experiments rather than using stoichiometric reagents. Chemical derivatives must be avoided as far as possible in any type of application as they often prove to be harmful. All chemical wastes should be disposed of in the best possible manner without causing any damage to the environment and living beings. We have to develop materials that will aid in the infusion of green chemistry into the curriculum such as green chemistry laboratory experiments and short courses on green chemistry. This article presents a brief description on green chemistry principles and its developments.

  19. Copper Nanoparticles in Click Chemistry.

    Science.gov (United States)

    Alonso, Francisco; Moglie, Yanina; Radivoy, Gabriel

    2015-09-15

    The challenges of the 21st century demand scientific and technological achievements that must be developed under sustainable and environmentally benign practices. In this vein, click chemistry and green chemistry walk hand in hand on a pathway of rigorous principles that help to safeguard the health of our planet against negligent and uncontrolled production. Copper-catalyzed azide-alkyne cycloaddition (CuAAC), the paradigm of a click reaction, is one of the most reliable and widespread synthetic transformations in organic chemistry, with multidisciplinary applications. Nanocatalysis is a green chemistry tool that can increase the inherent effectiveness of CuAAC because of the enhanced catalytic activity of nanostructured metals and their plausible reutilization capability as heterogeneous catalysts. This Account describes our contribution to click chemistry using unsupported and supported copper nanoparticles (CuNPs) as catalysts prepared by chemical reduction. Cu(0)NPs (3.0 ± 1.5 nm) in tetrahydrofuran were found to catalyze the reaction of terminal alkynes and organic azides in the presence of triethylamine at rates comparable to those achieved under microwave heating (10-30 min in most cases). Unfortunately, the CuNPs underwent dissolution under the reaction conditions and consequently could not be recovered. Compelling experimental evidence on the in situ generation of highly reactive copper(I) chloride and the participation of copper(I) acetylides was provided. The supported CuNPs were found to be more robust and efficient catalyst than the unsupported counterpart in the following terms: (a) the multicomponent variant of CuAAC could be applied; (b) the metal loading could be substantially decreased; (c) reactions could be conducted in neat water; and (d) the catalyst could be recovered easily and reutilized. In particular, the catalyst composed of oxidized CuNPs (Cu2O/CuO, 6.0 ± 2.0 nm) supported on carbon (CuNPs/C) was shown to be highly versatile and very

  20. Chemistry and sustainable environment (abstract)

    International Nuclear Information System (INIS)

    Chemistry is one of the oldest branches of science; the human beings had ever come across. It has consistently contributed towards meeting the human needs from the dawn of civilization. However, its role has multiplied since the inception of industrial revolution. Although anthropogenic activities have made the human life comfortable and even luxurious yet their impacts on the physical, biological and socio-economic environments had been destructive. Numerous kinds of chemicals have engulfed us and our environment. Modern chemistry has leading role in sculpting the present as well as future of human lifestyle. It is serving the man and other biodiversity by providing countless products in every sphere of life. At the same time it is playing villain role in the destruction of environment at an alarming rate. Today the world is confronted with heinous environmental issues hitherto unknown to the living beings mostly triggered by chemicals. Thousands of chemicals are used in industrial products, agricultural chemicals, persistent organic pollutants, freezers, pharmaceuticals, chemical and radiological warfare, construction industry, synthetic materials, electrical goods, medical gadgets etc. Some natural sources of chemicals are acid rains, volcanic eruptions, eutrophication and photochemical smog. The fact of matter is that chemicals are being consistently added into atmosphere, biosphere and lithosphere. For the sustainable environment it is imperative that the chemicals must not be added into human environment beyond its carrying capacity. It is responsibility of chemists to introduce environmentally benign and biodegradable chemicals. All types of chemistry need to be green and environment friendly. The scientists and engineers should develop chemicals and technologies which do not harm the living creatures during any stage of their life-cycle. (author)