WorldWideScience

Sample records for chemistry meets complex

  1. Quantum Chemistry Meets Rotational Spectroscopy for Astrochemistry: Increasing Molecular Complexity

    Science.gov (United States)

    Puzzarini, Cristina

    2016-06-01

    For many years, scientists suspected that the interstellar medium was too hostile for organic species and that only a few simple molecules could be formed under such extreme conditions. However, the detection of approximately 180 molecules in interstellar or circumstellar environments in recent decades has changed this view dramatically. A rich chemistry has emerged, and relatively complex molecules such as C60 and C70 are formed. Recently, researchers have also detected complex organic and potentially prebiotic molecules, such as amino acids, in meteorites and in other space environments. Those discoveries have further stimulated the debate on the origin of the building blocks of life in the universe. Rotational spectroscopy plays a crucial role in the investigation of planetary atmosphere and the interstellar medium. Increasingly these astrochemical investigations are assisted by quantum-mechanical calculations of structures as well as spectroscopic and thermodynamic properties to guide and support observations, line assignments, and data analysis in these new and chemically complicated situations. However, it has proved challenging to extend accurate quantum-chemical computational approaches to larger systems because of the unfavorable scaling with the number of degrees of freedom (both electronic and nuclear). In this contribution, it is demonstrated that it is now possible to compute physicochemical properties of building blocks of biomolecules with an accuracy rivaling that of the most sophisticated experimental techniques. We analyze the spectroscopic properties of representative building blocks of DNA bases (uracil and thiouracil), of proteins (glycine and glycine dipeptide analogue), and also of PAH (phenalenyl radical and cation). V. Barone, M. Biczysko, C. Puzzarini 2015, Acc. Chem. Res., 48, 1413

  2. Quantum Chemistry Meets Spectroscopy for Astrochemistry: Increasing Complexity toward Prebiotic Molecules.

    Science.gov (United States)

    Barone, Vincenzo; Biczysko, Malgorzata; Puzzarini, Cristina

    2015-05-19

    For many years, scientists suspected that the interstellar medium was too hostile for organic species and that only a few simple molecules could be formed under such extreme conditions. However, the detection of approximately 180 molecules in interstellar or circumstellar environments in recent decades has changed this view dramatically. A rich chemistry has emerged, and relatively complex molecules such as C60 and C70 are formed. Recently, researchers have also detected complex organic and potentially prebiotic molecules, such as amino acids, in meteorites and in other space environments. Those discoveries have further stimulated the debate on the origin of the building blocks of life in the universe. Many efforts continue to focus on the physical, chemical, and astrophysical processes by which prebiotic molecules can be formed in the interstellar dust and dispersed to Earth or to other planets.Spectroscopic techniques, which are widely used to infer information about molecular structure and dynamics, play a crucial role in the investigation of planetary atmosphere and the interstellar medium. Increasingly these astrochemical investigations are assisted by quantum-mechanical calculations of structures as well as spectroscopic and thermodynamic properties, such as transition frequencies and reaction enthalpies, to guide and support observations, line assignments, and data analysis in these new and chemically complicated situations. However, it has proved challenging to extend accurate quantum-chemical computational approaches to larger systems because of the unfavorable scaling with the number of degrees of freedom (both electronic and nuclear).In this Account, we show that it is now possible to compute physicochemical properties of building blocks of biomolecules with an accuracy rivaling that of the most sophisticated experimental techniques, and we summarize specific contributions from our groups. As a test case, we present the underlying computational machinery

  3. Complex Autocatalysis in Simple Chemistries.

    Science.gov (United States)

    Virgo, Nathaniel; Ikegami, Takashi; McGregor, Simon

    2016-01-01

    Life on Earth must originally have arisen from abiotic chemistry. Since the details of this chemistry are unknown, we wish to understand, in general, which types of chemistry can lead to complex, lifelike behavior. Here we show that even very simple chemistries in the thermodynamically reversible regime can self-organize to form complex autocatalytic cycles, with the catalytic effects emerging from the network structure. We demonstrate this with a very simple but thermodynamically reasonable artificial chemistry model. By suppressing the direct reaction from reactants to products, we obtain the simplest kind of autocatalytic cycle, resulting in exponential growth. When these simple first-order cycles are prevented from forming, the system achieves superexponential growth through more complex, higher-order autocatalytic cycles. This leads to nonlinear phenomena such as oscillations and bistability, the latter of which is of particular interest regarding the origins of life.

  4. 11(th) National Meeting of Organic Chemistry and 4(th) Meeting of Therapeutic Chemistry.

    Science.gov (United States)

    Sousa, Maria Emília; Araújo, Maria João; do Vale, Maria Luísa; Andrade, Paula B; Branco, Paula; Gomes, Paula; Moreira, Rui; Pinho E Melo, Teresa M V D; Freitas, Victor

    2016-01-01

    For the first time under the auspices of Sociedade Portuguesa de Química, the competences of two important fields of Chemistry are brought together into a single event, the 11st National Organic Chemistry Meeting and the the 4th National Medicinal Chemistry Meeting, to highlight complementarities and to promote new synergies. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report. PMID:27102166

  5. 11th National Meeting of Organic Chemistry and 4th Meeting of Therapeutic Chemistry

    Science.gov (United States)

    Sousa, Maria Emília; Araújo, Maria João; do Vale, Maria Luísa; Andrade, Paula B.; Branco, Paula; Gomes, Paula; Moreira, Rui; Pinho e Melo, Teresa M.V.D.; Freitas, Victor

    2016-01-01

    For the first time under the auspices of Sociedade Portuguesa de Química, the competences of two important fields of Chemistry are brought together into a single event, the 11st National Organic Chemistry Meeting and the the 4th National Medicinal Chemistry Meeting, to highlight complementarities and to promote new synergies. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report. PMID:27102166

  6. 11th National Meeting of Organic Chemistry and 4th Meeting of Therapeutic Chemistry

    Directory of Open Access Journals (Sweden)

    Maria Emília Sousa

    2016-03-01

    Full Text Available For the first time under the auspices of Sociedade Portuguesa de Química, the competences of two important fields of Chemistry are brought together into a single event, the 11st National Organic Chemistry Meeting and the the 4th National Medicinal Chemistry Meeting, to highlight complementarities and to promote new synergies. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report.

  7. 11(th) National Meeting of Organic Chemistry and 4(th) Meeting of Therapeutic Chemistry.

    Science.gov (United States)

    Sousa, Maria Emília; Araújo, Maria João; do Vale, Maria Luísa; Andrade, Paula B; Branco, Paula; Gomes, Paula; Moreira, Rui; Pinho E Melo, Teresa M V D; Freitas, Victor

    2016-03-17

    For the first time under the auspices of Sociedade Portuguesa de Química, the competences of two important fields of Chemistry are brought together into a single event, the 11st National Organic Chemistry Meeting and the the 4th National Medicinal Chemistry Meeting, to highlight complementarities and to promote new synergies. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report.

  8. 11th National Meeting of Organic Chemistry and 4th Meeting of Therapeutic Chemistry

    OpenAIRE

    Maria Emília Sousa; Maria João Araújo; Maria Luísa do Vale; Andrade, Paula B.; Paula Branco; Paula Gomes; Rui Moreira; Teresa M. V. D. Pinho e Melo; Victor de Freitas

    2016-01-01

    For the first time under the auspices of Sociedade Portuguesa de Química, the competences of two important fields of Chemistry are brought together into a single event, the 11st National Organic Chemistry Meeting and the the 4th National Medicinal Chemistry Meeting, to highlight complementarities and to promote new synergies. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report.

  9. 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.

  10. Complex Chemistry on Interstellar Grains

    Science.gov (United States)

    Widicus Weaver, Susanna L.; Kelley, Matthew J.; Blake, Geoffrey A.

    the preliminary results of this model will be presented. The reactions incorporated into this model include photolysis of grain surface species, radical-radical combination reactions between photolysis products, aldehyde proton abstraction reactions, and radical recombination reactions between the photolysis products and aldehyde radicals. H addition reactions dominate the grain surface chemistry at low temperature, forming simple species such as water, methanol, and formaldehyde. Photolysis of simple grain mantle constituents leads to the production of surface radicals that can efficiently compete with H addition reactions at warmer temperatures, and so periodic thermal processing of grain mantles will lead to the buildup of more complex species such as formic acid, methyl formate, formamide, acetaldehyde, and glycolaldehyde. Aldehyde proton abstraction reactions can efficiently compete with single-atom addition reactions at both low and high temperatures, and so the mobile radicals can then react with the resultant aldehyde radicals to form more complex species. Simpler species will be favored at low temperature, but these radicals may also be stored in the grain mantle at low temperature and undergo more complex reactions upon grain mantle heating in hot core regions.

  11. International meeting on radiation chemistry and processing

    International Nuclear Information System (INIS)

    The conference heard 76 papers; the abstracts of 74 of them were inputted in INIS. They deal with the basic principles and mechanisms of radiation chemistry, with radiolysis, radiation cross-linking of polymers, with methods and instruments for irradiation beam dosimetry, and with radiation application in the irradiation of foods and wastes. (M.D.)

  12. View at Croatian Chemistry through Meetings of Croatian

    Directory of Open Access Journals (Sweden)

    Trinajstić, N.

    2007-10-01

    Full Text Available The 20th Croatian meeting of chemists and chemical engineers was a proper occasion to consider the past meetings and their role in the development of Croatian chemistry and chemical engineering last 40 years, because these meetings reflect to a large extent the state of these sciences in Croatia. The circumstances that lead to establishment of the Croatian meetings of chemists and chemical engineers and the role of Professor Marijan Laaan (1919-1981 who started these meetings by organizing the first one are described. He also organized the second and the seventh meeting. All persons who chaired these meetings are mentioned, as well as all the lecturers who won the Nobel Prize in chemistry. Especially emphasized is the participation of Vladimir Prelog (1906-1998 since the twentieth meeting was dedicated to him and to Leopold Ružička (1887-1976 - two excellent Croatian chemists who for their first-class research in organic chemistry won the Nobel Prize (Ružička in 1939 and Prelog 1975. The places where the meetings were held are listed. The structure of the meetings when the change of the meetings' title happened is delineated and the representation of various branches of chemistry according to the number of contributions is discussed. Similarly, the Croatian institutions according to the number ofcontributions of their staff-members and the contributors with the highest number of communications at each meeting are pointed out. Emphasized is the international character of these meetings and the countries from which the participants came are listed. Finally, only one contribution is discussed in detail - the report by Kata Mlinarić-Majerski and Zdenko Majerski on the preparation of [3.1.1]propellane inserted in the structure of adamantane. Adamantane chemistry in Croatia started with the first ever adamantane synthesis in 1941, when Prelog and Seiwerth prepared this cage hydrocarbon and is still going strong due to efforts by Kata Mlinaria

  13. The Complex Chemistry of Embedded Protostars

    DEFF Research Database (Denmark)

    Lykke, Julie Maria

    - or molecular astrophysics - has evolved fast in recent years, due to major technological advancements for radio telescopes. But some of the most central questions still remain unanswered: how, where and when are complex organic molecules formed around young stars? How complex can these molecules become......? Is there a difference in the chemistry for high- and low-mass protostars? The work in this thesis aim to provide answer for these questions by searching for molecules where they have not been detected before and by comparing the relative abundance of different molecules to models and laboratory work as well as between......- and low-mass sources. Modified models and laboratory work as well as more observations are therefore needed to further develop our understanding of the chemistry occurring in star-forming regions....

  14. Regional Meeting on Chemistry - Book of abstracts

    International Nuclear Information System (INIS)

    Preparation and characterization of rare earth complexes; corrosion of AISI-304 steel, in ethanol; photolysis of ruthenium complexes; preparation of chromium-51 by irradiation of vanadium; separation of rare earths by using Zn2+ and Amberlite IR-120 are described. (A.R.H.)

  15. Proceedings of the 4. National Meeting on Analytical Chemistry - Abstracts

    International Nuclear Information System (INIS)

    The 4. National Meeting on Analytical Chemistry includes analysis of nuclear interest elements with nuclear and non nuclear methods and the elements not interest of nuclear energy with nuclear methods. The materials analysed are rocks, ores, metals alloys, waters, plants and biological materials. (C.G.C.)

  16. Tc Chemistry in HLW: Role of Organic Complexants

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Nancy S.; Conradsen, Steven D.

    2003-06-01

    Tc complexation with organic compounds in tank waste plays a significant role in the redox chemistry of Tc and the partitioning of Tc between the supernatant and sludge components in waste tanks. These processes need to be understood so that strategies to effectively remove Tc from high-level nuclear waste prior to waste immobilization can be developed and so that long-term consequences of Tc remaining in residual waste after sludge removal can be evaluated. Only limited data on the stability of Tc-organic complexes exists and even less thermodynamic data on which to develop predictive models of Tc chemical behavior is available. To meet these challenges we are conducting a research program to study to develop thermodynamic data on Tc-organic complexation over a wide range of chemical conditions. We will attempt to characterize Tc-speciation in actual tank waste using state-of-the-art analytical organic chemistry, separations, and speciation techniques to validate our model. On the basis of such studies we will develop credible model of Tc chemistry in HLW that will allow prediction of Tc speciation in tank waste and Tc behavior during waste pretreatment processing and in waste tank residuals.

  17. Technetium Chemistry in HLW: Role of Organic Complexants

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Nancy J.; Blanchard, David L. Jr.; Campbell, James A.; Cho, Herman M.; Rai, Dhanpat, Rai; Xia, Yuanxian; Conradson, Steven D.

    2002-06-01

    Technetium complexation with organic compounds in tank waste plays a significant role in the redox chemistry of Tc and the partitioning of Tc between the supernatant and sludge components in waste tanks. These processes need to be understood so that strategies to effectively remove Tc from high-level nuclear waste prior to waste immobilization can be developed and so that longterm consequences of Tc remaining in residual waste after sludge removal can be evaluated. Only limited data on the stability of Tc-organic complexes exists, and even less thermodynamic data on which to develop predictive models of Tc chemical behavior is available. To meet these challenges, we present a research program to study Tc-speciation in actual tank waste using state-of-the-art analytical organic chemistry, separations, and speciation techniques. On the basis of such studies, we will acquire thermodynamic data for the identified Tc-organic complexes over a wide range of chemical conditions in order to develop credible models to predict Tc speciation in tank waste and Tc behavior during waste pretreatment processing and in waste tank residuals.

  18. Abstracts of the 1. Brazilian Meeting on Analytical Chemistry

    International Nuclear Information System (INIS)

    Abstracts from experimental studies on analytical chemistry are presented. Several techniques have been used, such as: neutron activation analysis, potentiometry, optical emission spectroscopy, alpha and gamma spectroscopy, atomic absorption spectrophotometry, radiometric analysis, fission track detection, complexometry and others. Samples analysed are of various kinds: environmental materials (soil, water, air), rocks, coal, lanthanide complexes, polycarbonates and synthetic quartz. (C.L.B.)

  19. 76 FR 6499 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2011-02-04

    ... FOUNDATION Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory... Chemistry (1191). Dates and Times: February 17, 2011; 8 a.m.-6 p.m. February 18, 2011; 8 a.m.-5 p.m. Place... Meeting: Part-open. Contact Person: Dr. Robert Kuczkowski, Program Director, Chemistry Centers...

  20. 76 FR 12996 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2011-03-09

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee... Chemistry (CHE), 1191. Dates and Times: March 31, 2011; 8 a.m.-5:30 p.m. April 1, 2011; 8 a.m.-5 p.m. April... Meeting: Part-open. Contact Person: Dr. Robert Kuczkowski, Program Director, Chemistry Centers...

  1. 76 FR 24922 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2011-05-03

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee...: Name: Proposal Review Panel for Chemistry 1191. Date and Time: May 17, 2011, 8:30 a.m.- 5 p.m.; May 18..., Acting Deputy Division Director, Chemistry Centers Program, Division of Chemistry, Room 1055,...

  2. 75 FR 5353 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2010-02-02

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee... and The University of Massachusetts, Proposal Review Panel for Chemistry ( 1191). Dates and Times...: Department of Chemistry, Georgia Institute of Technology, Atlanta, GA 30332. Department of Chemistry,...

  3. 77 FR 10574 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2012-02-22

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee... Information: Katharine Covert, Program Director, Division of Chemistry, National Science Foundation,...

  4. 78 FR 31978 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2013-05-28

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee... Innovation Program, Division of Chemistry, Room 1055, National Science Foundation, 4201 Wilson...

  5. 78 FR 4464 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2013-01-22

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee..., Program Director, Centers for Chemical Innovation Program, Division of Chemistry, Room 1055,...

  6. Novel Intramolecular Coordination Chemistry of Some New Metallocene Complexes

    Institute of Scientific and Technical Information of China (English)

    钱延龙; 黄吉玲

    2001-01-01

    This article summarizes the recent results of systematic study on the novel intramolecular cordination chemistry of some new substituted metallocene complexes made by our research group.It deals with the syntheses,reactions,structures of 65 new substituted metallocene complexes and some application of such coordination in homogeneous ctalysis,especially the structural chemistry of such novel intramolecular coordination complexes,and the mechanism of elimination and cyclization of such coordination compounds,as well as their control action in catalytic reactions.

  7. Ultrafast chemistry in complex and confined systems

    Indian Academy of Sciences (India)

    Partha Dutta; Kankan Bhattacharyya

    2004-01-01

    Self-organized molecular assemblies play a crucial role in many natural and biological processes. Recent applications of ultrafast laser spectroscopy and computer simulations revealed that chemistry in a confined environment is fundamentally different from that in ordinary solutions. Many recent examples of slow dynamics in constrained environments and their biological implications are discussed.

  8. Editorial of Special Issue Ruthenium Complex: The Expanding Chemistry of the Ruthenium Complexes

    Directory of Open Access Journals (Sweden)

    Ileana Dragutan

    2015-09-01

    Full Text Available Recent trends in Ru complex chemistry are surveyed with emphasis on the development of anticancer drugs and applications in catalysis, polymers, materials science and nanotechnology.

  9. 75 FR 20007 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2010-04-16

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee... by NSF Division of Chemistry (1191). Dates & Times: May 9, 2010; 8 p.m.-9 p.m., May 10, 2010; 8 a.m.- 9 p.m., May 11, 2010; 8 a.m.-1 p.m. Place: Department of Chemistry, California Institute...

  10. 77 FR 42341 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2012-07-18

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee...: Name: ChemMatCARS Site Visit, 2011 Awardees by NSF Division of Chemistry (1191). Dates & Times: July 23..., Division of Chemistry, Room 1055, National Science Foundation, 4201 Wilson Boulevard, Arlington, VA...

  11. 76 FR 24921 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2011-05-03

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee...: Name: Proposal Review Panel for Chemistry, 1191. Date and Time: May 12, 2011, 8:30 a.m.-5 p.m.; May 13, 2011, 8:30 a.m.-2 p.m. Place: Center for Chemistry at the Space-Time Limit, University of...

  12. 75 FR 3942 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2010-01-25

    ... Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee... Chemistry, 1191. Dates & Times: February 23, 2010; 8:30 a.m.-4:30 p.m. February 24, 2010; 8:30 a.m.-4 p.m..., Chemistry Centers Program, Division of Materials Research, Room 1055, National Science Foundation,...

  13. An introduction to the chemistry of complex compounds

    CERN Document Server

    Grinberg, Aleksander Abramovich; Trimble, R F

    1962-01-01

    An Introduction to the Chemistry of Complex Compounds discusses the fundamental concepts that are essential in understanding the underlying principles of complex compounds. The coverage of the book includes the compounds of the hexa, penta, and tetrammine type; compounds of the tri, dl, monoamine and hexacido types for the coordination number of 6; and complex compounds with a coordination number of 4. The text also covers the effects and chemical properties of complex compounds, such as the nature of the force of complex formation; the mutual effects of coordinated groups; and acid-base prope

  14. Complex Dynamics in Nonequilibrium Economics and Chemistry

    Science.gov (United States)

    Wen, Kehong

    Complex dynamics provides a new approach in dealing with economic complexity. We study interactively the empirical and theoretical aspects of business cycles. The way of exploring complexity is similar to that in the study of an oscillatory chemical system (BZ system)--a model for modeling complex behavior. We contribute in simulating qualitatively the complex periodic patterns observed from the controlled BZ experiments to narrow the gap between modeling and experiment. The gap between theory and reality is much wider in economics, which involves studies of human expectations and decisions, the essential difference from natural sciences. Our empirical and theoretical studies make substantial progress in closing this gap. With the help from the new development in nonequilibrium physics, i.e., the complex spectral theory, we advance our technique in detecting characteristic time scales from empirical economic data. We obtain correlation resonances, which give oscillating modes with decays for correlation decomposition, from different time series including S&P 500, M2, crude oil spot prices, and GNP. The time scales found are strikingly compatible with business experiences and other studies in business cycles. They reveal the non-Markovian nature of coherent markets. The resonances enhance the evidence of economic chaos obtained by using other tests. The evolving multi-humped distributions produced by the moving-time -window technique reveal the nonequilibrium nature of economic behavior. They reproduce the American economic history of booms and busts. The studies seem to provide a way out of the debate on chaos versus noise and unify the cyclical and stochastic approaches in explaining business fluctuations. Based on these findings and new expectation formulation, we construct a business cycle model which gives qualitatively compatible patterns to those found empirically. The soft-bouncing oscillator model provides a better alternative than the harmonic oscillator

  15. 77 FR 27804 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2012-05-11

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee...: Partially-Open. Contact Person: Zeev Rosenzweig, Program Director, Division of Chemistry, National...

  16. Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry

    OpenAIRE

    Rappoport, Dmitrij; Galvin, Cooper J.; Zubarev, Dmitry; Aspuru-Guzik, Alan

    2014-01-01

    While structures and reactivities of many small molecules can be computed efficiently and accurately using quantum chemical methods, heuristic approaches remain essential for modeling complex structures and large-scale chemical systems. Here, we present a heuristics-aided quantum chemical methodology applicable to complex chemical reaction networks such as those arising in cell metabolism and prebiotic chemistry. Chemical heuristics offer an expedient way of traversing high-dimensional reacti...

  17. Abstracts of the 1. Regional Meeting on Chemistry

    International Nuclear Information System (INIS)

    Abstracts from papers on Analytical, Inorganic and Organic Chemistry as well as on Physico-Chemistry are presented. Emphasis is given to the following subjects: use of nuclear techniques for chemical analysis, separation processes, studies about reaction kinetics and thermodynamic properties, radioisotopes production and applications, labelled compounds, electron-molecule collisions, construction of measuring instruments and data acquisition systems. (C.L.B.)

  18. Abstracts of the 3. Brazilian Meeting on Analytical Chemistry

    International Nuclear Information System (INIS)

    Abstracts from experimental research works on analytical chemistry are presented. The following techniques were mainly used: differential pulse polarography, atomic absorption spectrophotometry, ion exchange chromatography and gamma spectroscopy. (C.L.B.)

  19. Flax Complex When West Meets East

    Institute of Scientific and Technical Information of China (English)

    Feng Yuan

    2007-01-01

    @@ At the end of November, representatives from the CELC, who represent the top quality of European Linen Industry, arrived in Beijing to meet their biggest customers, Chinese factories who produce linen yarns. The two sides met under the organization of China Bastand Leaf Fiber Association,and the meeting was held in the China National Textile and Apparel Council.

  20. Technetium Chemistry in HLW: Role of Organic Complexants

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Nancy J.; Blanchard, David L., Jr.; Cho, Herman M.; Xia, Yuanxian; Campbell, James A.; Rai, Dhanpat; Conradson, Steven D.

    2004-06-01

    Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. Technetium is thought to have followed U in bismuth phosphate, REDOX and PUREX extraction campaigns and the Cs and Sr isotope recovery efforts. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry. The fate of Tc in the insoluble salts that constitute tank residuals is of paramount importance due to the long half-life and environmental mobility of Tc. Knowledge gaps include determination of the Tc oxidation state, the stability of reduced Tc solution species, and interactions with possible organic complexants in HLW. The objective of this renewal proposal is to continue to pursue fundamental understanding of Tc solution chemistry that provides the basis to make knowledgeable decisions and predictions of Tc behavior during retrieval operations and in tank residuals.

  1. 1: Redox chemistry of bimetallic fulvalene complexes; 2: Oligocyclopentadienyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D. S. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley Lab., CA (United States). Chemical Sciences Div.

    1993-11-01

    The electrochemistry of the heterobimetallic complexes (fulvalene)WFe(CO){sub 5} (30) and (fulvalene)WRu(CO){sub 5} (31) has been investigated. Compound 30 is reduced in two one-electron processes, and this behavior was exploited synthetically to prepare a tetranuclear dimer by selective metal reduction. Complex 31 displayed a distinction between the metals upon reoxidation of the dianion, allowing the formation of a dimer by selective metal anion oxidation. The redox behavior of 30 led to an investigation of the use of electrocatalysis to effect metal-specific ligand substitution. It was found that reduction of 30 with a catalytic amount of CpFe(C{sub 6}Me{sub 6}) (97) in the presence of excess P(OMe){sub 3} or PMe{sub 3} led to the formation of the zwitterions (fulvalene)[W(CO){sub 3}{sup {minus}}][Fe(CO)PR{sub 3}{sup +}] (107, R = P(OMe){sub 3}; 108, R = PMe{sub 3}). Compound 31 also displayed unique behavior with different reducing agents, as the monosubstituted zwitterion (fulvalene)[W(CO){sub 3}{sup {minus}}][Ru(CO){sub 2}(PMe{sub 3}){sup +}] was obtained when 97 was used while the disubstituted complex (fulvalene) [W(CO){sub 3}{sup {minus}}] [Ru(CO)(PMe{sub 3}){sub 2}{sup +}] was produced when Cp*Fe(C{sub 6}Me{sub 6}) was the catalyst. Potential synthetic routes to quatercyclopentadienyl complexes were also explored. Various attempts to couple heterobimetallic fulvalene compounds proved to be unsuccessful. 138 refs.

  2. Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics

    Science.gov (United States)

    2016-01-01

    Summary The atom-by-atom control provided by synthetic organic chemistry presents a means of generating new functional nanomaterials with great precision. Bringing together these two very disparate skill sets is, however, quite uncommon. This autobiographical review provides some insight into how my program evolved, as well as giving some idea of where we are going. PMID:27559417

  3. Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics.

    Science.gov (United States)

    Rotello, Vincent M

    2016-01-01

    The atom-by-atom control provided by synthetic organic chemistry presents a means of generating new functional nanomaterials with great precision. Bringing together these two very disparate skill sets is, however, quite uncommon. This autobiographical review provides some insight into how my program evolved, as well as giving some idea of where we are going.

  4. Organic chemistry meets polymers, nanoscience, therapeutics and diagnostics.

    Science.gov (United States)

    Rotello, Vincent M

    2016-01-01

    The atom-by-atom control provided by synthetic organic chemistry presents a means of generating new functional nanomaterials with great precision. Bringing together these two very disparate skill sets is, however, quite uncommon. This autobiographical review provides some insight into how my program evolved, as well as giving some idea of where we are going. PMID:27559417

  5. Influence of water chemistry on fuel cladding behaviour. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    For the purpose of the meeting water chemistry included the actual practice, the water chemistry monitoring and the on-going research. Corrosion included also hydriding, recent observations made in reactors, modelling and the recent research carried out. Fifty seven participants representing twenty countries attended the thirty formal presentations and the subsequent discussions. The thirty papers presented were split into five sessions covering, Reactor experience, Mechanism and Modelling, Oxidation and hydriding, On-line monitoring of water chemistry and the review of existing and advanced water chemistries. Four panel discussions including ''Corrosion mechanism and Modelling'', ''Corrosion and Hydriding'', ''Plant Experience and Loop Experiments'', Water Chemistry, Current Practice and Emerging Solutions'' and ''On-line Monitoring of Water Chemistry and Corrosion'' were organized. The main points of discussion focussed on the optimization of water chemistry, the compatibility of potassium water chemistry with the utilization of Zircaloy 4 or the utilization of zirconium niobium cladding with lithium water chemistry. The effect of the fabrication route and of the cladding composition (Sn content) on the corrosion kinetics, the state of the art and the correlative gaps in cladding corrosion modelling and the recent developments of on-line monitoring of water chemistry together with examination of suitable developments, were also discussed. Refs, figs, tabs

  6. "Structure and dynamics in complex chemical systems: Gaining new insights through recent advances in time-resolved spectroscopies.” ACS Division of Physical Chemistry Symposium presented at the Fall National ACS Meeting in Boston, MA, August 2015

    Energy Technology Data Exchange (ETDEWEB)

    Crawford, Daniel [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2016-09-26

    8-Session Symposium on STRUCTURE AND DYNAMICS IN COMPLEX CHEMICAL SYSTEMS: GAINING NEW INSIGHTS THROUGH RECENT ADVANCES IN TIME-RESOLVED SPECTROSCOPIES. The intricacy of most chemical, biochemical, and material processes and their applications are underscored by the complex nature of the environments in which they occur. Substantial challenges for building a global understanding of a heterogeneous system include (1) identifying unique signatures associated with specific structural motifs within the heterogeneous distribution, and (2) resolving the significance of each of multiple time scales involved in both small- and large-scale nuclear reorganization. This symposium focuses on the progress in our understanding of dynamics in complex systems driven by recent innovations in time-resolved spectroscopies and theoretical developments. Such advancement is critical for driving discovery at the molecular level facilitating new applications. Broad areas of interest include: Structural relaxation and the impact of structure on dynamics in liquids, interfaces, biochemical systems, materials, and other heterogeneous environments.

  7. Modification of heterogeneous chemistry by complex substrate morphology

    Energy Technology Data Exchange (ETDEWEB)

    Henson, B.F.; Buelow, S.J.; Robinson, J.M.

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Chemistry in many environmental systems is determined at some stage by heterogeneous reaction with a surface. Typically the surface exists as a dispersion or matrix of particulate matter or pores, and a determination of the heterogeneous chemistry of the system must address the extent to which the complexity of the environmental surface affects the reaction rates. Reactions that are of current interest are the series of chlorine nitrate reactions important in polar ozone depletion. The authors have applied surface spectroscopic techniques developed at LANL to address the chemistry of chlorine nitrate reactions on porous nitric and sulfuric acid ice surfaces as a model study of the measurement of complex, heterogeneous reaction rates. The result of the study is an experimental determination of the surface coverage of one adsorbed reagent and a mechanism of reactivity based on the dependence of this coverage on temperature and vapor pressure. The resulting mechanism allows the first comprehensive modeling of chlorine nitrate reaction probability data from several laboratories.

  8. The 2009 Lindau Nobel Laureate Meeting: Martin Chalfie, Chemistry 2008

    OpenAIRE

    Chalfie, Martin

    2010-01-01

    American Biologist Martin Chalfie shared the 2008 Nobel Prize in Chemistry with Roger Tsien and Osamu Shimomura for their discovery and development of the Green Fluorescent Protein (GFP). Martin Chalfie was born in Chicago in 1947 and grew up in Skokie Illinois. Although he had an interest in science from a young age-- learning the names of the planets and reading books about dinosaurs-- his journey to a career in biological science was circuitous. In high school, Chalfie enjoyed his AP Chemi...

  9. Abstracts of the 2. Brazilian Meeting on Analytical Chemistry

    International Nuclear Information System (INIS)

    Abstracts of theoretical and experimental works on Qualitative and Quantitative Analytical Chemistry are presented. Among the various analytical techniques used, emphasis is given to: neutron activation analysis, crystal doping and annealing, isotopic tracing, fission tracks detection, atomic absorption spectrophotometry, emission spectroscopy with induced coupled plasma, X-ray diffraction, nuclear magnetic resonance, mass spectrometry, polarography, ion exchange and/or thin-layer chromatography, electrodeposition, potentiometric titration and others. (C.L.B)

  10. Complex Surface Concentration Gradients by Stenciled "Electro Click Chemistry"

    DEFF Research Database (Denmark)

    Hansen, Thomas Steen; Lind, Johan Ulrik; Daugaard, Anders Egede;

    2010-01-01

    Complex one- or two-dimensional concentration gradients of alkynated molecules are produced on azidized conducting polymer substrates by stenciled "electro click chemistry". The latter describes the local electrochemical generation of catalytically active Cu(I) required to complete a "click...... reaction" between alkynes and azides at room temperature. A stencil on the counter electrode defines the shape and multiplicity of the gradient(s) on the conducting polymer substrate, while the specific reaction conditions control gradient steepness and the maximum concentration deposited. Biologically...

  11. Complex engineering systems science meets technology

    CERN Document Server

    Minai, Ali A; Bar-Yam, Yaneer

    2006-01-01

    Every time that we take money out of an ATM, surf the internet or simply turn on a light switch, we enjoy the benefits of complex engineered systems. Systems like power grids and global communication networks are so ubiquitous in our daily lives that we usually take them for granted, only noticing them when they break down. But how do such amazing technologies and infrastructures come to be what they are? How are these systems designed? How do distributed networks work? How are they made to respond rapidly in 'real time'? And as the demands that we place on these systems become increasingly complex, are traditional systems-engineering practices still relevant? This volume examines the difficulties that arise in creating highly complex engineered systems and new approaches that are being adopted. Topics addressed range from the formal representation and classification of distributed networked systems to revolutionary engineering practices inspired by biological evolution. By bringing together the latest resear...

  12. 77 FR 5852 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2012-02-06

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee...--Executive Session. 9:30 a.m.-11:45 a.m. Open--Center for Quantum Information and Computation for...

  13. 77 FR 22613 - Proposal Review Panel for Chemistry; Notice of Meeting

    Science.gov (United States)

    2012-04-16

    ... From the Federal Register Online via the Government Publishing Office NATIONAL SCIENCE FOUNDATION Proposal Review Panel for Chemistry; Notice of Meeting In accordance with the Federal Advisory Committee Act (Pub. L. 92- 463, as amended), the National Science Foundation announces the following...

  14. Discussion meeting on nuclear-, radio- and radiation chemistry - basics and applications

    International Nuclear Information System (INIS)

    The following fields have been represented at this meeting: 1. nuclear reactions and properties of the formed products; 2. geo- and cosmochemistry; 3. chemistry of actinides and other radioisotopes; 4. radioanalysis; 5. isotope applications; 6. nuclear fuel cycle. Single papers are listed under appropriate categories. (RB)

  15. Ruthenium Vinylidene and Acetylide Complexes. An Advanced Undergraduate Multi-technique Inorganic/Organometallic Chemistry Experiment

    Science.gov (United States)

    McDonagh, Andrew M.; Deeble, Geoffrey J.; Hurst, Steph; Cifuentes, Marie P.; Humphrey, Mark G.

    2001-02-01

    This experiment describes the isolation and characterization of complexes containing examples of two important monohapto ligands, namely vinylidene (C=CHR) and alkynyl (C ? CR) ligands. The former is a tautomer of acetylene that has minimal (10-10 s) existence as an uncomplexed molecule, providing an interesting example of the stabilization of reactive organic species at transition metals--an important motif in organometallic chemistry. The latter ligand affords complexes that have attracted a great deal of interest recently for their potentially useful electronic or optical properties, illustrating a major focus of contemporary organometallic chemistry, the search for useful materials. The particular strength of this experiment is in demonstrating the utility of a range of spectroscopic and analytical techniques in inorganic complex identification. The students observe unusual chemical shifts in the 13C NMR (vinylidene metal-bound carbon), meet heteronuclear NMR (31P), assign intense metal-to-ligand charge transfer (MLCT) bands in the UV-visible spectra, observe the utility of mass spectra in characterizing complexes of poly-isotopic transition metals, and are introduced to redox potentials (cyclic voltammetry).

  16. Gas-phase chemistry of ruthenium and rhodium carbonyl complexes.

    Science.gov (United States)

    Cao, Shiwei; Wang, Yang; Qin, Zhi; Fan, Fangli; Haba, Hiromitsu; Komori, Yukiko; Wu, Xiaolei; Tan, Cunmin; Zhang, Xin

    2016-01-01

    Short-lived ruthenium and rhodium isotopes were produced from a (252)Cf spontaneous fission (SF) source. Their volatile carbonyl complexes were formed in gas-phase reactions in situ with the carbon-monoxide containing gas. A gas-jet system was employed to transport the volatile carbonyls from the recoil chamber to the chemical separation apparatus. The gas-phase chemical behaviors of these carbonyl complexes were studied using an online low temperature isothermal chromatography (IC) technique. Long IC columns made up of FEP Teflon were used to obtain the chemical information of the high-volatile Ru and Rh carbonyls. By excluding the influence of precursor effects, short-lived isotopes of (109-110)Ru and (111-112)Rh were used to represent the chemical behaviours of Ru and Rh carbonyls. Relative chemical yields of about 75% and 20% were measured for Ru(CO)5 and Rh(CO)4, respectively, relative to the yields of KCl aerosols transported in Ar gas. The adsorption enthalpies of ruthenium and rhodium carbonyl complexes on a Teflon surface were determined to be around ΔHads = -33(+1)(-2) kJ mol(-1) and -36(+2)(-1) kJ mol(-1), respectively, by fitting the breakthrough curves of the corresponding carbonyl complexes with a Monte Carlo simulation program. Different from Mo and Tc carbonyls, a small amount of oxygen gas was found to be not effective for the chemical yields of ruthenium and rhodium carbonyl complexes. The general chemical behaviors of short-lived carbonyl complexes of group VI-IX elements were discussed, which can be used in the future study on the gas-phase chemistry of superheavy elements - Bh, Hs, and Mt carbonyls. PMID:26573993

  17. Chemistry and Properties of Complex Intermetallics from Metallic Fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Kanatzidis, Mercouri G. [Northwestern Univ., Evanston, IL (United States)

    2015-03-28

    This project investigated the reaction chemistry and synthesis of new intermetallic materials with complex compositions and structures using metallic fluxes as solvents. It was found that the metallic fluxes offer several key advantages in facilitating the formation and crystal growth of new materials. The fluxes mostly explored were liquid aluminum, gallium and indium. The main purpose of this project was to exploit the potential of metallic fluxes as high temperature solvent for materials discovery in the broad class of intermetallics. This work opened new paths to compound formation. We discovered many new Si (or Ge)-based compounds with novel structures, bonding and physicochemical properties. We created new insights about the reaction chemistry that is responsible for stabilizing the new materials. We also studied the structural and compositional relationships to understand their properties. We investigated the use of Group-13 metals Al, Ga and In as solvents and have generated a wide variety of new results including several new ternary and quaternary materials with fascinating structures and properties as well as new insights as to how these systems are stabilized in the fluxes. The project focused on reactions of metals from the rare earth element family in combination with transition metals with Si and Ge. For example molten gallium has serves both as a reactive and non-reactive solvent in the preparation and crystallization of intermetallics in the system RE/M/Ga/Ge(Si). Molten indium behaves similarly in that it too is an excellent reaction medium, but it gives compounds that are different from those obtained from gallium. Some of the new phase identified in the aluminide class are complex phases and may be present in many advanced Al-matrix alloys. Such phases play a key role in determining (either beneficially or detrimentally) the mechanical properties of advanced Al-matrix alloys. This project enhanced our basic knowledge of the solid state chemistry

  18. Water Chemistry and Clad Corrosion/Deposition Including Fuel Failures. Proceedings of a Technical Meeting

    International Nuclear Information System (INIS)

    Corrosion is a principal life limiting degradation mechanism in nuclear steam supply systems, particularly taking into account the trends in increasing fuel burnup, thermal ratings and cycle length. Further, many plants have been operating with varying water chemistry regimes for many years, and issues of crud (deposition of corrosion products on other surfaces in the primary coolant circuit) are of significant concern for operators. At the meeting of the Technical Working Group on Fuel Performance and Technology (TWGFPT) in 2007, it was recommended that a technical meeting be held on the subject of water chemistry and clad corrosion and deposition, including the potential consequences for fuel failures. This proposal was supported by both the Technical Working Group on Advanced Technologies for Light Water Reactors (TWG-LWR) and the Technical Working Group on Advanced Technologies for Heavy Water Reactors (TWG-HWR), with a recommendation to hold the meeting at the National Nuclear Energy Generating Company ENERGOATOM, Ukraine. This technical meeting was part of the IAEA activities on water chemistry, which have included a series of coordinated research projects, the most recent of which, Optimisation of Water Chemistry to Ensure Reliable Water Reactor Fuel Performance at High Burnup and in Ageing Plant (FUWAC) (IAEATECDOC-1666), concluded in 2010. Previous technical meetings were held in Cadarache, France (1985), Portland, Oregon, USA (1989), Rez, Czech Republic (1993), and Hluboka nad Vltavou, Czech Republic (1998). This meeting focused on issues associated with the corrosion of fuel cladding and the deposition of corrosion products from the primary circuit onto the fuel assembly, which can cause overheating and cladding failure or lead to unplanned power shifts due to boron deposition in the clad deposits. Crud deposition on other surfaces increases radiation fields and operator dose and the meeting considered ways to minimize the generation of crud to avoid

  19. Complexes and clusters of water relevant to atmospheric chemistry: H2O complexes with oxidants.

    Science.gov (United States)

    Sennikov, Petr G; Ignatov, Stanislav K; Schrems, Otto

    2005-03-01

    Experimental observations and data from quantum chemical calculations on complexes between water molecules and small, oxygen-containing inorganic species that play an important role as oxidants in the atmosphere (O(1D), O(3P), O2(X3sigmag), O2(b1sigmag+), O3, HO, HOO, HOOO, and H2O2) are reviewed, with emphasis on their structure, hydrogen bonding, interaction energies, thermodynamic parameters, and infrared spectra. In recent years, weakly bound complexes containing water have increasingly attracted scientific attention. Water in all its phases is a major player in the absorption of solar and terrestrial radiation. Thus, complexes between water and other atmospheric species may have a perceivable influence on the radiative balance and contribute to the greenhouse effect, even though their concentrations are low. In addition, they can play an important role in the chemistry of the Earth's atmosphere, particularly in the oxidation of trace gases. Apart from gas-phase complexes, the interactions of oxidants with ice surfaces have also received considerable advertency lately due to their importance in the chemistry of snow, ice clouds, and ice surfaces (e.g., ice shields in polar regions). In paleoclimate--respectively paleoenvironmental--studies, it is essential to understand the transfer processes from the atmosphere to the ice surface. Consequently, special attention is being paid here to the intercomparison of the properties of binary complexes and the complexes and clusters of more complicated compositions, including oxidants adsorbed on ice surfaces, where ice is considered a kind of large water cluster. Various facts concerning the chemistry of the Earth's atmosphere (concentration profiles and possible influence on radical reactions in the atmosphere) are discussed. PMID:15799459

  20. Proceedings of the specialists' meeting on the chemistry and technology of actinide elements 2011

    International Nuclear Information System (INIS)

    This report contains the Proceedings of the 17th Specialists' Meeting on the Chemistry and Technology of Actinide Elements, which was held at Research Reactor Institute, Kyoto University, on February 15, 2012. This specialists' meeting has been held annually since 1994, and this is the 17th meeting for the fiscal year 2011. The accident of Fukushima Daiich Nuclear Power Plant, which occurred on March 11, 2011, showed the presence of defect in Japanese past approach to keep nuclear system safe. There is the need to improve existing technological and operational problems, as well as regulatory problems, but we should be aware of the significance of recovering social trust and peoples' peace of mind with the nuclear power. It should be noted that public's anxiety on the backend issue of nuclear system is remarkably big, and thus we must try to provide an understandable solution to them. In this meeting, we dealt with actinide chemistry and technology, which are related to the advanced nuclear fuel cycle development and the disposal of the HLW or TRU wastes. This is because, in the backend of the nuclear system, Actinide and TRU elements have substantial importance, because all of reprocessing, geologic disposal, and partitioning and transmutation depend significantly on the chemistry and technology of Actinides. Therefore, we have continued discussion and information exchange on the Actinide issues over 16 years, and this year's 17th meeting had a special meaning as the first one after the accident. In this context in this 17th meeting, we tried to return to the fundamentals of molten salt chemistry, which is the base of the dry reprocessing development. In addition, in order to expand our attitude by crossing over the fence of nuclear society, we tried to explore the potential of the adoption of molten salt chemistry to the general industry. This was a small new attempt in compliance with the recent tendency to nuclear power reduction in

  1. Meeting on flows of granular materials in complex geometries

    Energy Technology Data Exchange (ETDEWEB)

    Passman, S.L.; Fukushima, E.; Evans, R.E. [eds.

    1994-11-01

    The International Energy Agency Fossil Fuel Multiphase Flow Sciences Agreement has been in effect since 1986. The traditional mechanism for the effort has been information exchange, effected by the inclusion of scientists in annual Executive committee meetings, by exchange of reports and papers, and by visits of scientists to one another`s institutions. In a sequence of informal meetings and at the 1993 Executive committee meeting, held in Pittsburgh, US in March 1994, it was decided that more intensive interactions could be productive. A candidate for such interactions would be specific projects. Each of these would be initiated through a meeting of scientists in which feasibility of the particular project was decided, followed by relatively intense international co-operation in which the work would be done. This is a report of the first of these meetings. Official or unofficial representatives from Canada, italy, japan, mexico, the United Kingdom, and the US met in Albuquerque, New Mexico, US, to consider the subject Flows of Granular Materials in Complex Geometries. Representatives of several other countries expressed interest but were unable to attend this meeting. Sixteen lectures were given on aspects of this topic. It was decided that a co-operative effort was desirable and possible. The most likely candidate for the area of study would be flows in bins and hoppers. Each of the countries wishing to co-operate will pursue funding for its effort. This report contains extended abstracts of the sixteen presentations and a transcription of the final discussion.

  2. Proceedings of the DAE-BRNS theme meeting on chemistry in atomic energy programme

    International Nuclear Information System (INIS)

    The pivotal role played by chemistry in all the stages of atomic energy programme, right from mineral exploration, materials processing, fuel fabrication, coolant, control and structural materials, reactor chemistry, fuel recycling and actinide partitioning to radioactive waste management, has been explicitly demonstrated in the last few decades. The discoveries and developments in chemical sciences that have contributed to the formulation and successful implementation of our nuclear programme are enormous. It is to the credit of all our colleagues of Department of Atomic Energy to reckon the chronology of mile stones in our programme and how they place our nation on the global map of nuclear energy. The theme meeting on Chemistry in Atomic Energy Programme is an outcome of the thinking of some of our colleagues in BARC to take stock of the accomplishments made hitherto and to prepare a roadmap to meet the challenges of future advanced reactor regimes, while safeguarding the strategic interests of mankind. It is not out-of-context to record here that India, with its rich experience, is poised to play a major role in the global nuclear power programme, through bilateral international collaborations as well as on the platform of IAEA. Papers relevant to INIS are indexed separately

  3. Symposium on the Physical Chemistry of Solar Energy Conversion, Indianapolis American Chemical Society Meetings, Fall 2013

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Tianquan [PI, Emory Univ.

    2013-09-20

    The Symposium on the Physical Chemistry of Solar Energy Conversion at the Fall ACS Meeting in Indianapolis, IN (Sept. 8-12) featured the following sessions (approx. 6 speakers per session): (1) Quantum Dots and Nanorods for Solar Energy Conversion (2 half-day sessions); (2) Artificial Photosynthesis: Water Oxidation; (3) Artificial Photosynthesis: Solar Fuels (2 half-day sessions); (4) Organic Solar Cells; (5) Novel Concepts for Solar Energy Conversion (2 half-day sessions); (6) Emerging Techniques for Solar Energy Conversion; (7) Interfacial Electron Transfer

  4. Supported Organometallic Complexes: Surface Chemistry, Spectroscopy, Catalysis, and Homogeneous Models

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Tobin J. [Northwestern Univ., Evanston, IL (United States); Stalzer, Madelyn M. [Northwestern Univ., Evanston, IL (United States); Delferro, Massimiliano [Northwestern Univ., Evanston, IL (United States)

    2016-09-09

    The goal of this project is to model, understand at a fundamental level, expand, and exploit pathways by which organometallic molecules of varying nuclearity undergo chemisorptive activation and catalytic activity enhancement on solid surfaces. Such processes connect to real-world, large-scale industrial hydrocarbon processes and to manufacturing cleaner, greener, more environmentally acceptable products, including those from renewable resources. This research program combines catalyst synthesis, surface chemistry and spectroscopy, homogeneous analogue catalysis, structural analysis, and computation, and involves collaboration with national laboratory and industrial researchers. The objectives are to: 1) Investigate mononuclear and binuclear organometallic chemisorption on “super Brønsted acid” and related oxide surfaces, 2) Synthesize and characterize mononuclear and polynuclear catalyst precursors for understanding-based surface and solution phase catalysis, 3) Use this information to produce new types of efficient energy storage materials, 4) Computationally model both solution phase and chemisorbed catalysts, and investigate their reactivity modes. Of relevance to national energy issues is the potential to transform/metathesize inert saturated hydrocarbons,to drive “uphill” processes by coupling to exoergic transformations, to better utilize biofeedstocks (e.g., Dow’s world-scale Brazilian non-petroleum polyethylene process), and to address challenges articulated in recent BES Catalysis BRN and Grand Research Challenges reports. The long-range objective is therefore to understand and exploit (catalyst)∙∙∙(catalyst) and (catalyst )∙∙∙(surface/cocatalyst) interactions for new, instructive reactivity patterns, and to connect activating surface environments with mechanistically less complex solution environments. The information obtained is then fed back into further catalyst discovery efforts. We have pursued correlated synthesis

  5. Macromolecular crowding: chemistry and physics meet biology (Ascona, Switzerland, 10-14 June 2012).

    Science.gov (United States)

    Foffi, G; Pastore, A; Piazza, F; Temussi, P A

    2013-08-02

    conference held in Ascona from 10 to 14 June 2012. In the unique scenario of the Maggiore lake and absorbed in the magic atmosphere of the Centro Stefano Franscini (CSF) at Monte Verità, we enjoyed three-and-a-half days of intense and inspiring activity, where not only many of the most prominent scientists working on macromolecular crowding, but also experts in closely related fields such as colloids and soft matter presented their work. The meeting was intended and has been organized to bring theoreticians and experimentalists together in the attempt to promote an active dialogue. Moreover, we wanted different disciplines to be represented, notably physics and chemistry, besides biology, as cross-fertilization is proving an increasingly fundamental source of inspiration and advancement. This issue of Physical Biology (PB) features a selection of the oral contributions presented at the conference, expanded in the form of research or review articles. PB, one of the scientific journals of the Institute of Physics (IOP), is one of the most dynamic and lively forums active at the interface between biology on one side, and physics and mathematics on the other. As its mission is stated by IOP, PB 'focuses on research in which physics-based approaches lead to new insights into biological systems at all scales of space and time, and all levels of complexity'. For these reasons, and also in view of its high reputation and broad readership, PB appears to be the ideal place for disseminating the thriving pieces of research presented at the conference. We are extremely grateful to PB and its kind and efficient editorial staff who helped make this issue a great scientific follow-up to the conference. The opening lecture of the conference, the first of four day-opening keynote lectures, was given by Allen P Minton from NIH (USA), possibly the most influential among the pioneers in the field. He provided a lucid and well-thought-out overview of the concept of macromolecular crowding

  6. SUPPORT FOR CHEMISTRY SYMPOSIA AT THE 2011 AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE MEETING FEBRUARY 17-21, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Prof. Charles Casey, University of Wisconsin-Madison

    2011-08-20

    This proposal supported Chemistry Symposia at the 2011 American Association for the Advancement of Science (AAAS) Meeting in Washington, DC February 17-21, 2011. The Chemistry Section of AAAS presented an unusually strong set of symposia for the 2011 AAAS meeting to help celebrate the 2011 International Year of Chemistry. The AAAS meeting provided an unusual opportunity to convey the excitement and importance of chemistry to a very broad audience and allowed access to a large contingent of the scientific press. Excellent suggestions for symposia were received from AAAS Chemistry Fellows and from the chairs of the American Chemical Society Technical Divisions. The AAAS Chemistry executive committee selected topics that would have wide appeal to scientists, the public, and the press for formal proposals of symposia. The symposia proposals were peer reviewed by AAAS. The Chemistry Section made a strong case to the program selection committee for approval of the chemistry symposia and 6 were approved for the 2011 annual meeting. The titles of the approved symposia were: (1) Powering the Planet: Generation of Clean Fuels from Sunlight and Water, (2) Biological Role and Consequences of Intrinsic Protein Disorder, (3) Chemically Speaking: How Organisms Talk to Each Other, (4) Molecular Self-Assembly and Artificial Molecular Machines, (5) Frontiers in Organic Materials for Information Processing, Energy and Sensors, and (6) Celebrating Marie Curie's 100th Anniversary of Her Nobel Prize in Chemistry. The Chemistry Section of AAAS is provided with funds to support only 1-2 symposia a year. Because of the much greater number of symposia approved in conjunction with observance of the 2011 International Year of Chemistry, additional support was sought from DOE to help support the 30 invited speakers and 8 symposia moderators/organizers. Support for the symposia provided the opportunity to highlight the excitement of current chemical research, to educate the public about

  7. Support for chemistry symposia at the 2011 American Association for the Advancement of Science meeting, February 17-21 2011

    Energy Technology Data Exchange (ETDEWEB)

    Casey, Charles [Univ. of Wisconsin, Madison, WI (United States)

    2011-08-20

    This proposal supported Chemistry Symposia at the 2011 American Association for the Advancement of Science (AAAS) Meeting in Washington, DC February 17-21, 2011. The Chemistry Section of AAAS presented an unusually strong set of symposia for the 2011 AAAS meeting to help celebrate the 2011 International Year of Chemistry. The AAAS meeting provided an unusual opportunity to convey the excitement and importance of chemistry to a very broad audience and allowed access to a large contingent of the scientific press. Excellent suggestions for symposia were received from AAAS Chemistry Fellows and from the chairs of the American Chemical Society Technical Divisions. The AAAS Chemistry executive committee selected topics that would have wide appeal to scientists, the public, and the press for formal proposals of symposia. The symposia proposals were peer reviewed by AAAS. The Chemistry Section made a strong case to the program selection committee for approval of the chemistry symposia and 6 were approved for the 2011 annual meeting. The titles of the approved symposia were: (1) Powering the Planet: Generation of Clean Fuels from Sunlight and Water, (2) Biological Role and Consequences of Intrinsic Protein Disorder, (3) Chemically Speaking: How Organisms Talk to Each Other, (4) Molecular Self-Assembly and Artificial Molecular Machines, (5) Frontiers in Organic Materials for Information Processing, Energy and Sensors, and (6) Celebrating Marie Curie's 100th Anniversary of Her Nobel Prize in Chemistry. The Chemistry Section of AAAS is provided with funds to support only 1-2 symposia a year. Because of the much greater number of symposia approved in conjunction with observance of the 2011 International Year of Chemistry, additional support was sought from DOE to help support the 30 invited speakers and 8 symposia moderators/organizers. Support for the symposia provided the opportunity to highlight the excitement of current chemical research, to educate the public about

  8. Uncertainty and error in complex plasma chemistry models

    Science.gov (United States)

    Turner, Miles M.

    2015-06-01

    Chemistry models that include dozens of species and hundreds to thousands of reactions are common in low-temperature plasma physics. The rate constants used in such models are uncertain, because they are obtained from some combination of experiments and approximate theories. Since the predictions of these models are a function of the rate constants, these predictions must also be uncertain. However, systematic investigations of the influence of uncertain rate constants on model predictions are rare to non-existent. In this work we examine a particular chemistry model, for helium-oxygen plasmas. This chemistry is of topical interest because of its relevance to biomedical applications of atmospheric pressure plasmas. We trace the primary sources for every rate constant in the model, and hence associate an error bar (or equivalently, an uncertainty) with each. We then use a Monte Carlo procedure to quantify the uncertainty in predicted plasma species densities caused by the uncertainty in the rate constants. Under the conditions investigated, the range of uncertainty in most species densities is a factor of two to five. However, the uncertainty can vary strongly for different species, over time, and with other plasma conditions. There are extreme (pathological) cases where the uncertainty is more than a factor of ten. One should therefore be cautious in drawing any conclusion from plasma chemistry modelling, without first ensuring that the conclusion in question survives an examination of the related uncertainty.

  9. Proceedings of the Scientific Meeting on Application of Isotopes and Radiation: Book 2. Chemistry, Environment, Radiation Process, And Industry

    International Nuclear Information System (INIS)

    The aim of the 10th Meeting of the Isotope and Radiation Application is to disseminate the result of research on application of nuclear techniques on agriculture, animal, biology, chemistry, environment, radiation process and industry. The meeting was held in Jakarta, 18-19 February 1998, and there were 6 invited papers and 52 papers indexed individually. This proceeding is divided by two volumes. Volume I and volume II consists of agriculture, animal, biology and chemistry, environment, radiation process and industry, respectively.(ID)

  10. Fission product chemistry in severe nuclear reactor accidents, specialists' meeting at JRC-Ispra, 15-17 January 1990

    International Nuclear Information System (INIS)

    A specialists' meeting was held at JRC-Ispra from 15 to 17 January 1990 to review the current understanding of fission-product chemistry during severe accidents in light water reactors. Discussions focussed on the important chemical phenomena that could occur across the wide range of conditions of a damaged nuclear plant. Recommendations for future chemistry work were made covering the following areas: (a) fuel degradation and fission-product release, (b) transport and attenuation processes in the reactor coolant system, (c) containment chemistry (iodine behaviour and core-concrete interactions). (author)

  11. Proceedings of the meeting on tunneling reaction and low temperature chemistry, 97 October. Tunneling reaction and quantum medium

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Tetsuo; Aratono, Yasuyuki; Ichikawa, Tsuneki; Shiotani, Masaru [eds.

    1998-02-01

    Present report is the proceedings of the 3rd Meeting on Tunneling Reaction and Low Temperature Chemistry held in Oct. 13 and 14, 1997. The main subject of the meeting is `Tunneling Reaction and Quantum Medium`. In the meeting, the physical and chemical phenomena in the liquid helium such as quantum nucleation, spectroscopy of atoms and molecules, and tunneling abstraction reaction of tritium atom were discussed as the main topics as well as the tunneling reactions in the solid hydrogen and organic compounds. Through the meetings held in 1995, 1996, and 1997, the tunneling phenomena proceeding at various temperatures (room temperature to mK) in the wide fields of chemistry, biology, and physics were discussed intensively and the importance of the tunneling phenomena in the science has been getting clear. The 12 of the presented papers are indexed individually. (J.P.N.)

  12. Proceedings of the meeting on tunneling reaction and low temperature chemistry, 97 October. Tunneling reaction and quantum medium

    International Nuclear Information System (INIS)

    Present report is the proceedings of the 3rd Meeting on Tunneling Reaction and Low Temperature Chemistry held in Oct. 13 and 14, 1997. The main subject of the meeting is 'Tunneling Reaction and Quantum Medium'. In the meeting, the physical and chemical phenomena in the liquid helium such as quantum nucleation, spectroscopy of atoms and molecules, and tunneling abstraction reaction of tritium atom were discussed as the main topics as well as the tunneling reactions in the solid hydrogen and organic compounds. Through the meetings held in 1995, 1996, and 1997, the tunneling phenomena proceeding at various temperatures (room temperature to mK) in the wide fields of chemistry, biology, and physics were discussed intensively and the importance of the tunneling phenomena in the science has been getting clear. The 12 of the presented papers are indexed individually. (J.P.N.)

  13. Using advanced surface complexation models for modelling soil chemistry under forests: Solling forest, Germany

    International Nuclear Information System (INIS)

    Various dynamic soil chemistry models have been developed to gain insight into impacts of atmospheric deposition of sulphur, nitrogen and other elements on soil and soil solution chemistry. Sorption parameters for anions and cations are generally calibrated for each site, which hampers extrapolation in space and time. On the other hand, recently developed surface complexation models (SCMs) have been successful in predicting ion sorption for static systems using generic parameter sets. This study reports the inclusion of an assemblage of these SCMs in the dynamic soil chemistry model SMARTml and applies this model to a spruce forest site in Solling Germany. Parameters for SCMs were taken from generic datasets and not calibrated. Nevertheless, modelling results for major elements matched observations well. Further, trace metals were included in the model, also using the existing framework of SCMs. The model predicted sorption for most trace elements well. - Highlights: → Surface complexation models can be well applied in field studies. → Soil chemistry under a forest site is adequately modelled using generic parameters. → The model is easily extended with extra elements within the existing framework. → Surface complexation models can show the linkages between major soil chemistry and trace element behaviour. - Surface complexation models with generic parameters make calibration of sorption superfluous in dynamic modelling of deposition impacts on soil chemistry under nature areas.

  14. Macromolecular crowding: chemistry and physics meet biology (Ascona, Switzerland, 10-14 June 2012)

    Science.gov (United States)

    Foffi, G.; Pastore, A.; Piazza, F.; Temussi, P. A.

    2013-08-01

    held in Ascona from 10 to 14 June 2012. In the unique scenario of the Maggiore lake and absorbed in the magic atmosphere of the Centro Stefano Franscini (CSF) at Monte Verità, we enjoyed three-and-a-half days of intense and inspiring activity, where not only many of the most prominent scientists working on macromolecular crowding, but also experts in closely related fields such as colloids and soft matter presented their work. The meeting was intended and has been organized to bring theoreticians and experimentalists together in the attempt to promote an active dialogue. Moreover, we wanted different disciplines to be represented, notably physics and chemistry, besides biology, as cross-fertilization is proving an increasingly fundamental source of inspiration and advancement. This issue of Physical Biology (PB) features a selection of the oral contributions presented at the conference, expanded in the form of research or review articles. PB, one of the scientific journals of the Institute of Physics (IOP), is one of the most dynamic and lively forums active at the interface between biology on one side, and physics and mathematics on the other. As its mission is stated by IOP, PB 'focuses on research in which physics-based approaches lead to new insights into biological systems at all scales of space and time, and all levels of complexity'. For these reasons, and also in view of its high reputation and broad readership, PB appears to be the ideal place for disseminating the thriving pieces of research presented at the conference. We are extremely grateful to PB and its kind and efficient editorial staff who helped make this issue a great scientific follow-up to the conference. The opening lecture of the conference, the first of four day-opening keynote lectures, was given by Allen P Minton from NIH (USA), possibly the most influential among the pioneers in the field. He provided a lucid and well-thought-out overview of the concept of macromolecular crowding through an

  15. Macromolecular crowding: chemistry and physics meet biology (Ascona, Switzerland, 10-14 June 2012).

    Science.gov (United States)

    Foffi, G; Pastore, A; Piazza, F; Temussi, P A

    2013-08-01

    conference held in Ascona from 10 to 14 June 2012. In the unique scenario of the Maggiore lake and absorbed in the magic atmosphere of the Centro Stefano Franscini (CSF) at Monte Verità, we enjoyed three-and-a-half days of intense and inspiring activity, where not only many of the most prominent scientists working on macromolecular crowding, but also experts in closely related fields such as colloids and soft matter presented their work. The meeting was intended and has been organized to bring theoreticians and experimentalists together in the attempt to promote an active dialogue. Moreover, we wanted different disciplines to be represented, notably physics and chemistry, besides biology, as cross-fertilization is proving an increasingly fundamental source of inspiration and advancement. This issue of Physical Biology (PB) features a selection of the oral contributions presented at the conference, expanded in the form of research or review articles. PB, one of the scientific journals of the Institute of Physics (IOP), is one of the most dynamic and lively forums active at the interface between biology on one side, and physics and mathematics on the other. As its mission is stated by IOP, PB 'focuses on research in which physics-based approaches lead to new insights into biological systems at all scales of space and time, and all levels of complexity'. For these reasons, and also in view of its high reputation and broad readership, PB appears to be the ideal place for disseminating the thriving pieces of research presented at the conference. We are extremely grateful to PB and its kind and efficient editorial staff who helped make this issue a great scientific follow-up to the conference. The opening lecture of the conference, the first of four day-opening keynote lectures, was given by Allen P Minton from NIH (USA), possibly the most influential among the pioneers in the field. He provided a lucid and well-thought-out overview of the concept of macromolecular crowding

  16. Chemistry of dihydrogen complexes containing only phosphorus co-ligands

    Indian Academy of Sciences (India)

    Balaji R Jagirdar; Nisha Mathew

    2002-08-01

    A series of new dicationic dihydrogen complexes of ruthenium of the type cis-[(dppm)2Ru(2-H2)(L)][BF4]2 (dppm = Ph2PCH2PPh2; L = phosphite) have been prepared by protonating the precursor hydride complexes cis-[(dppm)2Ru(H)(L)][BF4] using HBF4$\\cdot$Et2O. The precursor hydride complexes have been obtained from trans-[(dppm)2Ru(H)(L)][BF4] (L = phosphite) via a rare acidcatalysed isomerization reaction in six coordinate species. The trans-[(dppm)2Ru(H)(L)][BF4] complexes (L = phosphine) upon protonation gave the isomerized derivatives, however, further addition of acid resulted in a five-coordinate species, [(dppm)2RuCl]+ presumably via an intermediate phosphine dihydrogen complex. The electronic as well as the steric properties of the co-ligands seem to strongly influence the structure-reactivity behaviour of this series of complexes.

  17. Symmetry and Complexity - Fundamental Concepts of Research in Chemistry

    Directory of Open Access Journals (Sweden)

    Klaus Mainzer

    1997-11-01

    Full Text Available Molecules have more or less symmetric and complex structures which can be defined in the mathematical framework of topology, group theory, dynamical systems theory, and quantum mechanics. But symmetry and complexity are by no means only theoretical concepts of research. Modern computer aided visualizations show real forms of matter which nevertheless depend on the technical standards of observation, computation, and representation. Furthermore, symmetry and complexity are fundamental interdisciplinary concepts of research inspiring the natural sciences since the antiquity.

  18. Art, Meet Chemistry; Chemistry, Meet Art: Case Studies, Current Literature, and Instrumental Methods Combined to Create a Hands-On Experience for Nonmajors and Instrumental Analysis Students

    Science.gov (United States)

    Nivens, Delana A.; Padgett, Clifford W.; Chase, Jeffery M.; Verges, Katie J.; Jamieson, Deborah S.

    2010-01-01

    Case studies and current literature are combined with spectroscopic analysis to provide a unique chemistry experience for art history students and to provide a unique inquiry-based laboratory experiment for analytical chemistry students. The XRF analysis method was used to demonstrate to nonscience majors (art history students) a powerful…

  19. Gas-phase chemistry of technetium carbonyl complexes.

    Science.gov (United States)

    Wang, Yang; Qin, Zhi; Fan, Fang-Li; Haba, Hiromitsu; Komori, Yukiko; Cao, Shi-Wei; Wu, Xiao-Lei; Tan, Cun-Min

    2015-05-28

    Gas-phase chemical behaviors of short-lived technetium carbonyl complexes were studied using a low temperature isothermal chromatograph (IC) coupled with a (252)Cf spontaneous fission (SF) source. Fission products recoiled from the (252)Cf SF source were thermalized in a mixed gas containing CO, and then technetium carbonyl complexes were formed from reactions between CO gas and various technetium isotopes. A gas-jet system was employed to transport the volatile carbonyl complexes from a recoil chamber to the IC. Short IC columns made of Fluorinated Ethylene Propylene (FEP) Teflon and quartz were used to obtain chemical information about the technetium carbonyl complexes. The results for the (104)Tc-(106)Tc carbonyl complexes were found to be strongly influenced by the precursors, and showed the chemical behaviors of (104)Mo-(106)Mo carbonyl complexes, respectively. However, (107)Tc and (108)Tc could represent the chemical information of the element technetium due to their high independent yields and the very short half-lives of their precursors (107)Mo and (108)Mo. An adsorption enthalpy of about ΔHads = -43 kJ mol(-1) was determined for the Tc carbonyl complexes on both the Teflon and quartz surfaces by fitting the breakthrough curves of the (107)Tc and (108)Tc carbonyl complexes with a Monte Carlo simulation program. Chemical yields of around 25% were measured for the Tc carbonyl complexes relative to the transport yields obtained with the gas-jet transport of KCl aerosol particles with Ar carrier gas. Furthermore, the influence of a small amount of O2 gas on the yields of the Mo and Tc carbonyl complexes was studied. PMID:25920667

  20. Complex Polymeric Architectures Synthesized and Functionalized using Robust Chemistries

    Science.gov (United States)

    Killops, Kathryn L.

    Niche applications for polymeric materials put stringent requirements on their properties and architecture. Although polymer synthesis techniques have improved significantly to produce well-defined materials with narrow molecular weight distributions from a variety of monomeric precursors, the final materials often require fine-tuning of the structure or functionality to achieve the properties necessary for a given high performance application. The ability to modify and synthesize soft materials in precise and predictable manner requires the use of robust, efficient, and orthogonal chemistries. The highly branched structure of dendrimers provides an ideal platform to rigorously evaluate the ability of a reaction to proceed with quantitative conversion and high specificity. In order to achieve a macromolecular structure having a monodisperse molecular weight of over 10,000 Da, highly efficient reactions must be used. The synthesis of dendrimers up to the fourth generation was accomplished using successive iterations of thiol--ene 'click' chemistry and esterification reactions. The high molecular weight dendrimers were subsequently derivitized at the periphery using a variety of functional groups to demonstrate the orthogonality of the thiol--ene reaction. An extension of this work provided direct comparison of the thermally- and photochemically-initiated thiol--ene reactions, as applied to the functionalization of polymers both along the backbone and at the chain ends. With block copolymers, access to nanoscale features is afforded by the propensity of two chemically-distinct, covalently-linked polymer chains phase separate into discrete domains. These nanoscopic features have important implications for high performance applications like microelectronics and water purification. Precise modification of these structures expands the number of applications that could benefit from their implementation. In the search for a poly(ethylene oxide)-based nanoparticle with

  1. Phase Chemistry of the Complexes of RE Amino Acids

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Forty-three phase diagrams of ternary system concerning rare earth salts, α-amino acids and water, which were constructed by phase equilibrium methods, were expounded. The influences of the factors such as cations, anions, the structure of amino acids, temperature on the phase diagrams were discussed. Under the guidance of phase equilibrium results, over 150 new solid complexes were prepared. IR, reflecting, UV, FS, and Raman spectra for these complexes were investigated and the regularity of “tripartite effect”, “tetrad effect”, “Nephelanxetic effect”, “Oddo-Harkins” was observed. Thermal decomposition processes of the complexes were confirmed. Based on the comparison with the known crystal structures of rare earth-amino acid-complexes, an estimation method for predicting the crystal structure data of series complexes was founded. The constant volume combustion energies of the complexes were determined by RBC-1 type rotating bomb calorimeter. The standard enthalpies of combustion and standard enthalpies of formation were calculated for these complexes.

  2. Energetic lanthanide complexes: coordination chemistry and explosives applications

    International Nuclear Information System (INIS)

    Metals are generally added to organic molecular explosives in a heterogeneous composite to improve overall heat and energy release. In order to avoid creating a mixture that can vary in homogeneity, energetic organic molecules can be directly bonded to high molecular weight metals, forming a single metal complex with Angstrom-scale separation between the metal and the explosive. To probe the relationship between the structural properties of metal complexes and explosive performance, a new series of energetic lanthanide complexes has been prepared using energetic ligands such as NTO (5-nitro-2,4-dihydro-1,2,4-triazole-3-one). These are the first examples of lanthanide NTO complexes where no water is coordinated to the metal, demonstrating novel control of the coordination environment. The complexes have been characterized by X-ray crystallography, NMR and IR spectroscopies, photoluminescence, and sensitivity testing. The structural and energetic properties are discussed in the context of enhanced blast effects and detection. Cheetah calculations have been performed to fine-tune physical properties, creating a systematic method for producing explosives with 'tailor made' characteristics. These new complexes will be benchmarks for further study in the field of metalized high explosives.

  3. Research data supporting "Extending motifs in lithiocuprate chemistry: unexpected structural diversity in thiocyanate complexes"

    OpenAIRE

    Peel, Andrew J.; Hedidi, Madani; Ghenia, Bentabed-Ababsa; Thierry, Roisnel; Mongin, Florence; Wheatley, Andrew E. H.

    2015-01-01

    Supporting data for the publication "Extending motifs in lithiocuprate chemistry: unexpected structural diversity in thiocyanate complexes". Single crystal X-ray diffraction structures and NMR spectroscopic data for complexes 8-11 in the paper. All four complexes were made at Cambridge in 2015 and were characterized in house in 2015. NMR spectra for compounds 15 and 16. These were made and characterized in Rennes in 2015.

  4. Quantum Chemistry Calculation of Quercetin-silver Complex

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Three possible molecular structures of quercetin-silver complexes obtained from the reaction of quercetin and Ag+ in equivalent molar ratio were designed and optimized by using Gaussian 98 program at the B3LYP/LanL2DZ basis set. Through theoretical analysis, one of the three designed structures is discovered to have the most stable coordination position. Then its geometry structure, natural bond orbital analyses, vibrational frequency and biological activity were performed. The results show that it has good stability and relatively stronger antioxidative activity because it is favorably attacked by O2-*. Therefore theoretical foundation is provided for the development of new quercetin metal complexes with higher activity antioxidants.

  5. Prebiotic coordination chemistry: The potential role of transition-metal complexes in the chemical evolution

    Science.gov (United States)

    Beck, M.

    1979-01-01

    In approaching the extremely involved and complex problem of the origin of life, consideration of the coordination chemistry appeared not only as a possibility but as a necessity. The first model experiments appear to be promising because of prebiotic-type synthesis by means of transition-metal complexes. It is especially significant that in some instances various types of vitally important substances (nucleic bases, amino acids) are formed simultaneously. There is ground to hope that systematic studies in this field will clarify the role of transition-metal complexes in the organizatorial phase of chemical evolution. It is obvious that researchers working in the fields of the chemistry of cyano and carbonyl complexes, and of the catalytic effect of transition-metal complexes are best suited to study these aspects of the attractive and interesting problem of the origin of life.

  6. Emergence of complex chemistry on an organic monolayer.

    Science.gov (United States)

    Prins, Leonard J

    2015-07-21

    In many origin-of-life scenarios, inorganic materials, such as FeS or mineral clays, play an important role owing to their ability to concentrate and select small organic molecules on their surface and facilitate their chemical transformations into new molecules. However, considering that life is made up of organic matter, at a certain stage during the evolution the role of the inorganic material must have been taken over by organic molecules. How this exactly happened is unclear, and, indeed, a big gap separates the rudimentary level of organization involving inorganic materials and the complex organization of cells, which are the building blocks of life. Over the past years, we have extensively studied the interaction of small molecules with monolayer-protected gold nanoparticles (Au NPs) for the purpose of developing innovative sensing and catalytic systems. During the course of these studies, we realized that the functional role of this system is very similar to that typically attributed to inorganic surfaces in the early stages of life, with the important being difference that the functional properties (molecular recognition, catalysis, signaling, adaptation) originate entirely from the organic monolayer rather than the inorganic support. This led us to the proposition that this system may serve as a model that illustrates how the important role of inorganic surfaces in dictating chemical processes in the early stages of life may have been taken over by organic matter. Here, we reframe our previously obtained results in the context of the origin-of-life question. The following functional roles of Au NPs will be discussed: the ability to concentrate small molecules and create different local populations, the ability to catalyze the chemical transformation of bound molecules, and, finally, the ability to install rudimentary signaling pathways and display primitive adaptive behavior. In particular, we will show that many of the functional properties of the system

  7. Yearly scientific meeting: chemistry in human health and environment protection. Bialystok'92

    International Nuclear Information System (INIS)

    The conference has been divided into 12 sections devoted to following topics: analytical chemistry; environmental chemistry; chemistry of natural compounds; chemistry of pharmaceutics and toxic compounds; chemistry in medicine; electrochemistry; young scientists forum; didactics and history of chemistry; chemistry and industry - technologies environment friendly; new trends in polymer science; crystallochemistry; pro-ecological actions in leather industry. Different analytical methods for determination of heavy methods and rare earths have been presented. Some of them have been successfully applied for the examination of environmental and biological materials. The basic chemical and physico-chemical studies including thermodynamic, crystal structure, coordination chemistry, sorption properties etc. have been extensively resented. The existence of radioactive elements in environment has been also investigated, especially in respect to municipal and industrial wastes and products of their processing. The radiation effects for different materials have been reported and discussed as well

  8. Para-Functionalized NCN-Pincer Palladium and Platinum Complexes as Building Blocks in Organometallic Chemistry

    NARCIS (Netherlands)

    Slagt, Martijn Quico

    2002-01-01

    A rapidly evolving field in chemistry is the application of organometallic and coordination complexes as building blocks or active components for the construction of new materials exhibiting specific catalytic, redox, optical or sensor activities. A central theme in the construction of these inorgan

  9. Trivalent metallocene chemistry of some uranium, titanium, and zirconium complexes

    Energy Technology Data Exchange (ETDEWEB)

    Lukens, W.W. Jr.

    1995-05-01

    Dicyclopentadienyluranium halide dimers have been prepared and their solution behavior examined. These molecules exist as dimers in solution, and the halide ligands undergo rapid site exchange on the NMR timescale above 50 C. Analogous dicyclopentadienyluranium hydroxide dimers have also been prepared; they oxidatively eliminate hydrogen to give the corresponding oxide dimers. Mechanism of this reaction is consistent with {alpha}migration of one of the hydroxide hydrogen atoms to a uranium center followed by elimination of hydrogen. Ground state of [(Me{sub 3}Si){sub 2}C{sub 5}H{sub 3}]{sub 3}M M = Nd, U and their base adducts has been examined by variable temperature magnetic susceptibility and EPR spectroscopy. The ground state is found to be {sup 4}I{sub 9/2} with a crystal field state consisting largely of J{sub z} = 1/2 lowest, in agreement with previous studies on tris-cyclopentadienylneodymium complexes. The zirconium metallocene Cp{sub 3}Zr has been prepared, characterized crystallographically, and its reactivity studied. Its chemical behavior is controlled by presence of an electron in the non-bonding, d{sub z}2 orbital which prevents formation of base adducts Of Cp{sub 3}Zr, but allows Cp{sub 3}Zr to abstract atoms from other molecules. Electonic and EPR spectra of Cp*{sub 2}TiX complexes, where Cp* is Me{sub 5}C{sub 5} and X is a monodentate, anionic ligand such as halide, have been studied. A {pi}-bonding spectrochemical series is developed, and trends in {pi}-bonding ability are found similar to those in other inorganic complexes. The {beta}-agostic interactions in Cp*{sub 2}TiN(Me)Ph have been examined using variable temperature EPR spectroscopy, and the enthalpy/entropy of the interaction determined. In Cp*{sub 2}TiEt, enthalpy of the {beta}-agostic interaction is {minus}1.9 kcal/mol. The titanocene anion, Cp*{sub 2}TiLi(TMEDA) (TMEDA is N,N,N`,N`-tetramethylethylenediamine), has been prepared and its structure determined.

  10. Developing a computer-based assessment of complex problem solving in Chemistry

    OpenAIRE

    Scherer, Ronny; Meßinger-Koppelt, Jenny; Tiemann, Rüdiger

    2014-01-01

    Background Complex problem-solving competence is regarded as a key construct in science education. But due to the necessity of using interactive and intransparent assessment procedures, appropriate measures of the construct are rare. This paper consequently presents the development and validation of a computer-based problem-solving environment, which can be used to assess students' performance on complex problems in Chemistry. The test consists of four scales, namely, under...

  11. Water-stable fac-{TcO₃}⁺ complexes - a new field of technetium chemistry.

    Science.gov (United States)

    Braband, Henrik

    2011-01-01

    The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of (99)Tc is essential to avoid its release into the environment. In this article the chemistry of technetium at its highest oxidation state (+VII) is reviewed with a special focus on recent developments which make water-stable complexes of the general type [TcO(3)(tacn-R)](+) (tacn-R = 1,4,7-triazacyclononane or derivatives) accessible. Complexes containing the fac-{TcO(3)}(+) core display a unique reactivity. In analogy to [OsO(4)] and [RuO(4)], complexes containing the fac-{TcO(3)}(+) core undergo with alkenes metal-mediated, vicinal cis-dihydroxylation reactions (alkene-glycol interconversion) in water via a (3+2)-cycloaddition reaction. Therefore, water-stable fac-{(99m)TcO(3)}(+) complexes pave the way for a new labeling strategy for radiopharmaceutical applications, based on (3+2)-cycloaddition reactions. This new concept for the labeling of biomolecules with small [(99m)TcO(3)(tacn-R)](+)-type complexes by way of a (3+2)-cycloaddition with alkenes is discussed in detail. The herein reported developments in high-valent technetium chemistry create a new field of research with this artificial element. This demonstrates the potential of fundamental research to provide new impetus of innovation for the development of new methods for radiopharmaceutical applications.

  12. Coordination Chemistry of Homoleptic Actinide(IV)-Thiocyanate Complexes.

    Science.gov (United States)

    Carter, Tyler J; Wilson, Richard E

    2015-10-26

    The synthesis, X-ray crystal structure, vibrational and optical spectroscopy for the eight-coordinate thiocyanate compounds, [Et4 N]4 [Pu(IV) (NCS)8 ], [Et4 N]4 [Th(IV) (NCS)8 ], and [Et4 N]4 [Ce(III) (NCS)7 (H2 O)] are reported. Thiocyanate was found to rapidly reduce plutonium to Pu(III) in acidic solutions (pHthiocyanate complex [Et4 N]4 [Pu(IV) (NCS)8 ] was crystallized when a large excess of [Et4 N][NCS] was present. This compound, along with its U(IV) analogue, maintains inner-sphere thiocyanate coordination in acetonitrile based on the observation of intense ligand-to-metal charge-transfer bands. Spectroscopic and crystallographic data do not support the interaction of the metal orbitals with the ligand π system, but support an enhanced An(IV) -NCS interaction, as the Lewis acidity of the metal ion increases from Th to Pu. PMID:26493880

  13. 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)

  14. Coordination chemistry of amine bis(phenolate) titanium complexes: tuning complex type and structure by ligand modification.

    Science.gov (United States)

    Tshuva, E Y; Goldberg, I; Kol, M; Goldschmidt, Z

    2001-08-13

    The coordination chemistry of titanium(IV) complexes of amine bis(phenolate) ligands was investigated by synthesizing various types of complexes and analyzing them specroscopically and structurally. Steric effects of tridentate [ONO]- and tetradentate [ONNO]-type ligands were studied by reacting the ligand precursors with titanium tetra(isopropoxide). [ONNO]-type ligands featuring an amine donor located on a pendant arm led to octahedral bis(isopropoxide) complexes, regardless of the steric bulk around the metal. Several such complexes having varying steric crowding were thus synthesized. On the other hand, steric effects were found to play a major role in determining the complex constitution when [ONO]-type ligands, featuring no side donor, were involved. Relatively sterically undemanding ligands led to octahedral bis(homoleptic) complexes, whereas increased steric bulk resulted in the formation of pentacoordinate bis(isopropoxide) complexes. These pentacoordinate complexes readily lead to bis(heteroleptic) complexes by reaction with nonsterically demanding [ONO]- and [ONNO]-type ligand precursors. In the latter case the sidearm nitrogen remains uncoordinated to the metal. The bis(isopropoxide) complexes of the [ONNO]-type ligands may also lead to bis(heteroleptic) complexes, however, these reactions are much slower. PMID:11487331

  15. Different worlds, different values : How girls and boys meet physics, chemistry and technology at the upper level of compulsory school

    OpenAIRE

    Staberg, Else-Marie

    1992-01-01

    This study investigates how Swedish pupils meet science (chemistry and physics) and technology in compulsory school. It explores girls' and boys' actions in and thoughts about these subjects. The study has a feminist perspective focusing on girls. Two teaching groups were followed from the start in grade 7 in compulsory school, when the pupils were 13 years old, until they made their choice of study programmes in upper secondary school in grade 9. The main methods were classroom observations ...

  16. Water chemistry and corrosion control of cladding and primary circuit components. Proceedings of a technical committee meeting

    International Nuclear Information System (INIS)

    Corrosion is the principal life limiting degradation mechanism in nuclear steam supply systems, especially taking into account the trends to increase fuel burnup, thermal rate and cycle length. Primary circuit components of water cooled power reactors have an impact on Zr-based alloys behaviour due to crud (primary circuit corrosion products) formation, transport and deposition on heat transfer surfaces. Crud deposits influence water chemistry, radiation and thermal hydraulic conditions near cladding surface, and by this way-Zr-based alloy corrosion. During the last decade, significant improvements were achieved in the reduction of the corrosion and dose rates by changing the cladding material for one more resistant to corrosion or by the improvement of water chemistry conditions. However, taking into account the above mentioned tendency for heavier fuel duties, corrosion and water chemistry, control will remain a serious task to work with for nuclear power plant operators and scientists, as well as development of generally accepted corrosion model of Zr-based alloys in a water environment in a new millennium. Upon the recommendation of the International Working Group on Water Reactor Fuel Performance and Technology, water chemistry and corrosion of cladding and primary circuit components are in the focus of the IAEA activities in the area of fuel technology and performance. At present the IAEA performs two co-ordinated research projects (CRPs): on On-line High Temperature Monitoring of Water Chemistry and Corrosion (WACOL) and on Activity Transport in Primary Circuits. Two CRPs deal with hydrogen and hydride degradation of the Zr-based alloys. A state-of-the-art review entitled: 'Waterside Corrosion of Zirconium Alloys in Nuclear Power Plants' was published in 1998. Technical Committee meetings on the subject were held in 1985 (Cadarache, France), 1989 (Portland, USA), 1993 (Rez, Czech Republic). During the last few years extensive exchange of experience in

  17. Late transition metal m-or chemistry and D6 metal complex photoeliminations

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, Paul [Univ. of Missouri, Columbia, MO (United States)

    2015-07-31

    With the goal of understanding and controlling photoreductive elimination reactions from d6 transition metal complexes as part of a solar energy storage cycle we have investigated the photochemistry of Pt(IV) bromo, chloro, hydroxo, and hydroperoxo complexes. Photoreductive elimination reactions occur for all of these complexes and appear to involve initial Pt-Br, Pt-Cl, or Pt-O bond fission. In the case of Pt-OH bond fission, the subsequent chemistry can be controlled through hydrogen bonding to the hydroxo group.

  18. Proceedings of the meeting on tunneling reaction and low temperature chemistry, 98 August. Tunneling reaction and its theory

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Tetsuo; Aratono, Yasuyuki; Ichikawa, Tsuneki; Shiotani, Masaru [eds.

    1998-10-01

    Present report is the proceedings of the 4th Meeting on Tunneling Reaction and Low Temperature Chemistry held in August 3 and 4, 1998. The main subject of the meeting is `Tunneling Reaction and Its Theory`. In the present meeting the theoretical aspects of tunneling phenomena in the chemical reaction were discussed intensively as the main topics. Ten reports were presented on the quantum diffusion of muon and proton in the metal and H{sub 2}{sup -} anion in the solid para-hydrogen, the theory of tunnel effect in the nuclear reaction and the tunneling reaction in the organic compounds. One special lecture was presented by Prof. J. Kondo on `Proton Tunneling in Solids`. The 11 of the presented papers are indexed individually. (J.P.N.)

  19. Proceedings of the meeting on tunneling reaction and low temperature chemistry, 98 August. Tunneling reaction and its theory

    International Nuclear Information System (INIS)

    Present report is the proceedings of the 4th Meeting on Tunneling Reaction and Low Temperature Chemistry held in August 3 and 4, 1998. The main subject of the meeting is 'Tunneling Reaction and Its Theory'. In the present meeting the theoretical aspects of tunneling phenomena in the chemical reaction were discussed intensively as the main topics. Ten reports were presented on the quantum diffusion of muon and proton in the metal and H2- anion in the solid para-hydrogen, the theory of tunnel effect in the nuclear reaction and the tunneling reaction in the organic compounds. One special lecture was presented by Prof. J. Kondo on 'Proton Tunneling in Solids'. The 11 of the presented papers are indexed individually. (J.P.N.)

  20. Water chemistry control to meet the advanced design and operation of light water reactors

    International Nuclear Information System (INIS)

    Water chemistry control is one of the key technologies to establish safe and reliable operation of nuclear power plants. The road maps on R and D plans for water chemistry of nuclear power systems in Japan have been proposed along with promotion of R and D related water chemistry improvement for the advanced application of light water reactors (LWRs). The technical trends were divided into four categories, dose rate reduction, structural integrity, fuel integrity and radioactive waste reduction, and latest technical break through for each category was shown for the advanced application of LWRs. At the same time, the technical break through and the latest movements for regulation of water chemistry were introduced for each of major organizations related to nuclear engineering in the world. The conclusions were summarized as follows; 1. Water chemistry improvements might contribute to achieve the advanced application of LWRs, while water chemistry should be often changed to achieve the advanced application of LWRs. 2. Only one solution for water chemistry control was not obtained for achieving the advanced application of LWRs, but miscellaneous solutions were possible for achieving one. Optimal water chemistry control was desired for having the good practices for satisfying multi-targets at the same time and it was much affected by the plant unique systems and operational history. 3. That meant it was difficult to determine water chemistry regulation targets for achieving application of LWRs but it was necessary to prepare suitable guideline for good achievement of application of LWRs. That meant the guideline should be recommendation for good practice in the plant. 4. The water chemistry guide line should be modified along with progress of plant operation and water chemistry and related technologies. (author)

  1. Structure Identification Using High Resolution Mass Spectrometry Data and the EPAs Chemistry Dashboard (ACS Fall meeting)

    Science.gov (United States)

    The iCSS Chemistry Dashboard is a publicly accessible dashboard provided by the National Center for Computation Toxicology at the US-EPA. It serves a number of purposes, including providing a chemistry database underpinning many of our public-facing projects (e.g. ToxCast and Exp...

  2. 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

  3. Para-Functionalized NCN-Pincer Palladium and Platinum Complexes as Building Blocks in Organometallic Chemistry

    OpenAIRE

    Slagt, Martijn Quico

    2002-01-01

    A rapidly evolving field in chemistry is the application of organometallic and coordination complexes as building blocks or active components for the construction of new materials exhibiting specific catalytic, redox, optical or sensor activities. A central theme in the construction of these inorganic building blocks is the targeted functionalization of ligands, either prior to or, less conventionally, after the metallation step. Ligand functionalization enables the immobilization of the tran...

  4. Analysis of Finnish chemistry Matriculation Examination questions according to Cognitive Complexity

    OpenAIRE

    Greta Tikkanen; Maija Aksela

    2012-01-01

    This paper presents an analysis of Finnish chemistry matriculation examination questions according to cognitive complexity. The research data consisted of 257 questions from 28 matriculation examinations between 1996 and 2009. Qualitative approach and theory-driven content analysis method using Bloom’s revised Taxonomy of Cognitive Objectives were employed in the research. The categories of the higher-order (HOCS) and lower-order cognitive skills (LOCS) were formed on the basis of earlier res...

  5. Cement encapsulation of low-level radioactive slurries of complex chemistry

    International Nuclear Information System (INIS)

    Investigations have been carried out to solidify in cement a low-level radioactive waste of complex chemistry which should be produced in a new plant designed to process radioactive effluents from CEA Cadarache Research Center. Direct cementation comes up against a major problem: a very long setting time of cement due to strong inhibition by borates from the waste. A two-stage process, including a chemical treatment prior to immobilization, has been elaborated and the resulted material characterized. (authors)

  6. Cement encapsulation of low-level radioactive slurries of complex chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Cau Dit Coumes, C. [CEA/Cadarache, Dept. d' Entreposage et de Stockage des Dechets (DESD), 13 - Saint-Paul-lez-Durance (France)

    2000-07-01

    Investigations have been carried out to solidify in cement a low-level radioactive waste of complex chemistry which should be produced in a new plant designed to process radioactive effluents from CEA Cadarache Research Center. Direct cementation comes up against a major problem: a very long setting time of cement due to strong inhibition by borates from the waste. A two-stage process, including a chemical treatment prior to immobilization, has been elaborated and the resulted material characterized. (authors)

  7. 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...

  8. Proceeding of the Scientific Meeting and Presentation on Basic Research of Nuclear Science and Technology: Book II. Nuclear Chemistry, Process Technology, and Radioactive Waste Processing and Environment

    International Nuclear Information System (INIS)

    The proceeding contains papers presented on Scientific Meeting and Presentation on on Basic Research of Nuclear Science and Technology, held in Yogyakarta, 25-27 April 1995. This proceeding is second part of two books published for the meeting contains papers on nuclear chemistry, process technology, and radioactive waste management and environment. There are 62 papers indexed individually. (ID)

  9. Probing the chemistry, electronic structure and redox energetics in pentavalent organometallic actinide complexes

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Christopher R [Los Alamos National Laboratory; Vaughn, Anthony E [Los Alamos National Laboratory; Morris, David E [Los Alamos National Laboratory; Kiplinger, Jaqueline L [Los Alamos National Laboratory

    2008-01-01

    Complexes of the early actinides (Th-Pu) have gained considerable prominence in organometallic chemistry as they have been shown to undergo chemistries not observed with their transition- or lanthanide metal counterparts. Further, while bonding in f-element complexes has historically been considered to be ionic, the issue of covalence remains a subject of debate in the area of actinide science, and studies aimed at elucidating key bonding interactions with 5f-orbitals continue to garner attention. Towards this end, our interests have focused on the role that metal oxidation state plays in the structure, reactivity and spectral properties of organouranium complexes. We report our progress in the synthesis of substituted U{sup V}-imido complexes using various routes: (1) Direct oxidation of U{sup IV}-imido complexes with copper(I) salts; (2) Salt metathesis with U{sup V}-imido halides; (3) Protonolysis and insertion of an U{sup V}-imido alkyl or aryl complex with H-N{double_bond}CPh{sub 2} or N{triple_bond}C-Ph, respectively, to form a U{sup V}-imido ketimide complex. Further, we report and compare the crystallographic, electrochemical, spectroscopic and magnetic characterization of the pentavalent uranium (C{sub 5}Me{sub 5}){sub 2}U({double_bond}N-Ar)(Y) series (Y = OTf, SPh, C{triple_bond}C-Ph, NPh{sub 2}, OPh, N{double_bond}CPh{sub 2}) to further interrogate the molecular, electronic, and magnetic structures of this new class of uranium complexes.

  10. Evolution of Multi-Component Anion Relay Chemistry (ARC): Construction of Architecturally Complex Natural and Unnatural Products#**

    OpenAIRE

    Smith, Amos B.; Wuest, William M.

    2008-01-01

    Efficient construction of architecturally complex natural and unnatural products is the hallmark of organic chemistry. Anion Relay Chemistry (ARC) - a multi-component coupling protocol - has the potential to provide the chemist with a powerful synthetic tactic, enabling efficient, rapid elaboration of structurally complex scaffolds in a single operation with precise stereochemical control. The ARC tactic can be subdivided into two main classes, comprising the relay of negative charge either t...

  11. 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)

  12. Complexes and Clusters of Water Relevant to Atmospheric Chemistry: H2O Complexes with Oxidants

    OpenAIRE

    Sennikov, Peter; Ignatov, Stanislav; Schrems, Otto

    2005-01-01

    Experimental observations and data from quantum chemical calculations related to the complexes between water molecules and small oxygen containing inorganic species which are playing an important role as oxidants (O(1D), O(3P), O2(X3Σg), O2(b1Σg+), O3, HO, HOO, HOOO, and H2O2) in the atmosphere are reviewed with emphasis on their structure, hydrogen bonding, interaction energies, thermodynamic parameters and IR spectra. In recent years, weakly bound complexes containing water have i...

  13. A COLD COMPLEX CHEMISTRY TOWARD THE LOW-MASS PROTOSTAR B1-b: EVIDENCE FOR COMPLEX MOLECULE PRODUCTION IN ICES

    International Nuclear Information System (INIS)

    Gas-phase complex organic molecules have been detected toward a range of high- and low-mass star-forming regions at abundances which cannot be explained by any known gas-phase chemistry. Recent laboratory experiments show that UV irradiation of CH3OH-rich ices may be an important mechanism for producing complex molecules and releasing them into the gas phase. To test this ice formation scenario, we mapped the B1-b dust core and nearby protostar in CH3OH gas using the IRAM 30 m telescope to identify locations of efficient non-thermal ice desorption. We find three CH3OH abundance peaks tracing two outflows and a quiescent region on the side of the core facing the protostar. The CH3OH gas has a rotational temperature of ∼10 K at all locations. The quiescent CH3OH abundance peak and one outflow position were searched for complex molecules. Narrow, 0.6-0.8 km s-1 wide, HCOOCH3 and CH3CHO lines originating in cold gas are clearly detected, CH3OCH3 is tentatively detected, and C2H5OH and HOCH2CHO are undetected toward the quiescent core, while no complex molecular lines were found toward the outflow. The core abundances with respect to CH3OH are ∼2.3% and 1.1% for HCOOCH3 and CH3CHO, respectively, and the upper limits are 0.7%-1.1%, which is similar to most other low-mass sources. The observed complex molecule characteristics toward B1-b and the pre-dominance of HCO-bearing species suggests a cold ice (below 25 K, the sublimation temperature of CO) formation pathway followed by non-thermal desorption through, e.g., UV photons traveling through outflow cavities. The observed complex gas composition together with the lack of any evidence of warm gas-phase chemistry provides clear evidence of efficient complex molecule formation in cold interstellar ices.

  14. Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts

    International Nuclear Information System (INIS)

    This document brings together the abstracts of the 39 presentations given at this meeting days on uranium, organized by the French geological society, and dealing with: 1 - Prospective study of the electronuclear technological transition; 2 - The front-end of the nuclear cycle: from the molecule to the process; 3 - Geophysics: recent changes; 4 - Use of well logging in uranium exploration; 5 - Genetical classification of thorium deposits; 6 - Genetical nomenclature of uranium sources; 7 - Uranium deposits linked to a Proterozoic discordance - retrospective; 8 - The use of spectral analysis techniques in uranium exploration: real-time mapping of clay alteration features; 9 - Development of functionalized silk-screened carbon electrodes for the analysis of uranium trace amounts; 10 - Study of the actinides solvation sphere in organic environment; 11 - Thermodynamic of uraniferous phases of interest for the nuclear cycle; 12 - Heap leaching of marginal minerals at Somair: from lab studies to the production of 700 t of uranium/year; 13 - Agglomeration phenomenology and role of iron in uranium heap leaching; 14 - Chloride uranyl complexes up to 300 deg. C along the saturation vapour curve: Raman spectroscopy analysis and metallogenic consequences; 15 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): vertical variability of argillaceous weathering; 16 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): contribution of irradiation defects in clays to the tracing of past uranium migrations; 17 - Uranium concentrations in mineralizing fluids of the Athabasca basin: analytical and experimental approach; 18 - Paleo-surfaces and metallic rooting: the autochthonous uranium of pre-Athabasca paleo-alterites, Canada; 19 - Distribution of argillaceous parageneses in the Imouraren deposit - Niger; 20 - Heat flux and radioelements concentration (U, Th, K) of precambrian basements: implications in terms of crust growth mechanisms, paleo

  15. The 2009 Lindau Nobel Laureate Meeting: Sir Harold Kroto, Chemistry 1996

    OpenAIRE

    Kroto, Harold

    2010-01-01

    English Chemist Harold Kroto shared the 1996 Nobel Prize in Chemistry with Robert Curl and Richard Smalley for their discovery of Fullerenes (C60), molecules composed completely of carbon (C60) that form hollow spheres (also known as Buckyballs), tubes, or ellipsoids. These structures hold the potential for use in future technologies ranging from drug development and antimicrobial agents, to armor and superconductors.

  16. Multifunctionality of organometallic quinonoid metal complexes: surface chemistry, coordination polymers, and catalysts.

    Science.gov (United States)

    Kim, Sang Bok; Pike, Robert D; Sweigart, Dwight A

    2013-11-19

    Quinonoid metal complexes have potential applications in surface chemistry, coordination polymers, and catalysts. Although quinonoid manganese tricarbonyl complexes have been used as secondary building units (SBUs) in the formation of novel metal-organometallic coordination networks and polymers, the potentially wider applications of these versatile linkers have not yet been recognized. In this Account, we focus on these diverse new applications of quinonoid metal complexes, and report on the variety of quinonoid metal complexes that we have synthesized. Through the use of [(η(6)-hydroquinone)Mn(CO)3](+), we are able to modify the surface of Fe3O4 and FePt nanoparticles (NPs). This process occurs either by the replacement of oleylamine with neutral [(η(5)-semiquinone)Mn(CO)3] at the NP surface, or by the binding of anionic [(η(4)-quinone)Mn(CO)3](-) upon further deprotonation of [(η(5)-semiquinone)Mn(CO)3] at the NP surface. We have demonstrated chemistry at the intersection of surface-modified NPs and coordination polymers through the growth of organometallic coordination polymers onto the surface modified Fe3O4 NPs. The resulting magnetic NP/organometallic coordination polymer hybrid material exhibited both the unique superparamagnetic behavior associated with Fe3O4 NPs and the paramagnetism attributable to the metal nodes, depending upon the magnetic range examined. By the use of functionalized [(η(5)-semiquinone)Mn(CO)3] complexes, we attained the formation of an organometallic monolayer on the surface of highly ordered pyrolitic graphite (HOPG). The resulting organometallic monolayer was not simply a random array of manganese atoms on the surface, but rather consisted of an alternating "up and down" spatial arrangement of Mn atoms extending from the HOPG surface due to hydrogen bonding of the quinonoid complexes. We also showed that the topology of metal atoms on the surface could be controlled through the use of quinonoid metal complexes. A quinonoid

  17. The role of SIMS in the investigation of the complex crystal chemistry of mica minerals

    International Nuclear Information System (INIS)

    A full characterisation of micas requires complete chemical analysis, including the determination of light elements, combined with Moessbauer spectroscopy or any technique suitable for the determination of ferric and ferrous iron contents, and crystal structural analysis (SCXRD). In this context, the SIMS technique is essential for a deeper understanding of the crystal chemistry of mica owing to its capability of precise and accurate quantification of light elements, i.e., H, Li, B, F, .... The role of SIMS is here outlined in the investigation of the complex crystal structure of mica, with new data on a set of volcanic samples, and their comparison with those from literature on trioctahedral micas from volcanic areas of Southern Italy. The importance of SIMS micro-spot (in-situ) analysis is here emphasized as a modern approach to gain insight into physico-chemical processes that affect grain-to-grain or intra-grain chemical variability in complex mineral structures.

  18. Big Data meets Quantum Chemistry Approximations: The $\\Delta$-Machine Learning Approach

    CERN Document Server

    Ramakrishnan, Raghunathan; Rupp, Matthias; von Lilienfeld, O Anatole

    2015-01-01

    Chemically accurate and comprehensive studies of the virtual space of all possible molecules are severely limited by the computational cost of quantum chemistry. We introduce a composite strategy that adds machine learning corrections to computationally inexpensive approximate legacy quantum methods. After training, highly accurate predictions of enthalpies, free energies, entropies, and electron correlation energies are possible, for significantly larger molecular sets than used for training. For thermochemical properties of up to 16k constitutional isomers of C$_7$H$_{10}$O$_2$ we present numerical evidence that chemical accuracy can be reached. We also predict electron correlation energy in post Hartree-Fock methods, at the computational cost of Hartree-Fock, and we establish a qualitative relationship between molecular entropy and electron correlation. The transferability of our approach is demonstrated, using semi-empirical quantum chemistry and machine learning models trained on 1 and 10\\% of 134k organ...

  19. Sunlight-initiated chemistry of aqueous pyruvic acid: building complexity in the origin of life.

    Science.gov (United States)

    Griffith, Elizabeth C; Shoemaker, Richard K; Vaida, Veronica

    2013-10-01

    Coupling chemical reactions to an energy source is a necessary step in the origin of life. Here, we utilize UV photons provided by a simulated sun to activate aqueous pyruvic acid and subsequently prompt chemical reactions mimicking some of the functions of modern metabolism. Pyruvic acid is interesting in a prebiotic context due to its prevalence in modern metabolism and its abiotic availability on early Earth. Here, pyruvic acid (CH3COCOOH, a C3 molecule) photochemically reacts to produce more complex molecules containing four or more carbon atoms. Acetoin (CH3CHOHCOCH3), a C4 molecule and a modern bacterial metabolite, is produced in this chemistry as well as lactic acid (CH3CHOHCOOH), a molecule which, when coupled with other abiotic chemical reaction pathways, can provide a regeneration pathway for pyruvic acid. This chemistry is discussed in the context of plausible environments on early Earth such as near the ocean surface and atmospheric aerosol particles. These environments allow for combination and exchange of reactants and products of other reaction environments (such as shallow hydrothermal vents). The result could be a contribution to the steady increase in chemical complexity requisite in the origin of life.

  20. The pharmaceutical biochemistry group: where pharmaceutical chemistry meets biology and drug delivery

    OpenAIRE

    Kalia, Yogeshvar; Perozzo, Remo; Scapozza, Leonardo

    2012-01-01

    Successful drug discovery and development of new therapeutics is a long, expensive multidisciplinary process needing innovation and the integration of smart cutting edge science and technology to overcome the challenges in taking a drug from the bench to the bedside. The research activities of the Pharmaceutical Biochemistry group span the drug discovery and development process, providing an interface that brings together pharmaceutical chemistry, biochemistry, structural biology, computation...

  1. Scandinavian Radiation Chemistry Meeting Studsvik and Stockholm, September 17-19, 1969

    International Nuclear Information System (INIS)

    The report contains the abstracts of papers, which are intended for presentation at the meeting. The complete papers will not be published collectively. The following subjects are discussed in the abstracts: Pulse radiolysis, water and aqueous solutions including vapour, inorganic systems, organic systems, monomers and polymers and biochemical systems

  2. High-Relaxivity MRI Contrast Agents: Where Coordination Chemistry Meets Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Eric J.; Datta, Ankona; Jocher, Christoph J.; Raymond, Kenneth N.

    2008-01-15

    The desire to improve and expand the scope of clinical magnetic resonance imaging (MRI) has prompted the search for contrast agents of higher efficiency. The development of better agents requires consideration of the fundamental coordination chemistry of the gadolinium(III) ion and the parameters that affect its efficacy as a proton relaxation agent. In optimizing each parameter, other practical issues such as solubility and in vivo toxicity must also be addressed, making the attainment of safe, high-relaxivity agents a challenging goal. Here we present recent advances in the field, with an emphasis on the hydroxypyridinone family of Gd{sup III} chelates.

  3. Proceedings of the Scientific Meeting and Presentation on Basic Researchin Nuclear Science and Technology part II: Nuclear Chemistry, Process Technology, Radioactive Waste Management and Environment

    International Nuclear Information System (INIS)

    Scientific Meeting and Presentation on Basic Research in Nuclear Scienceand Technology is an annual activity held by Centre for Research and Development of Advanced Technology, National Nuclear Energy Agency, for monitoring research activities achieved by the Agency. The papers presented in the meeting were collected into proceedings. These are the second part of the proceedings that contain 71 articles in the fields of nuclear chemistry, process technology, radioactive waste management, and environment (PPIN).

  4. Novel approach for labeling of biopolymers with DOTA complexes using in situ click chemistry for quantification.

    Science.gov (United States)

    He, Yide; Esteban-Fernández, Diego; Linscheid, Michael W

    2015-03-01

    In this work, we present a two-step labeling approach for the efficient tagging with lanthanide-containing complexes. For this purpose, derivatization of the cysteine residues with an alkyne group acting as linker was done before the DOTA complex was introduced using in situ click chemistry. The characterization of this new methodology is presented including the optimization of the labeling process, demonstration of the quantitative capabilities using both electrospray ionization mass spectrometry (ESI-MS) and inductively coupled plasma mass spectrometry (ICP-MS) detection, and study of the fragmentation behavior of the labeled peptides by collision-induced dissociation (CID) for identification purposes. The results show that, in terms of labeling efficiency, this new methodology improves previously developed DOTA-based label strategies, such as MeCAT-maleimide (metal-coded affinity tag, MeCAT-Mal) and MeCAT-iodoacetamide (MeCAT-IA) reagents. The goal of reducing the steric hindrance caused by the voluminous DOTA complex was fulfilled allowing both, quantification and identification of labeled biopolymers.

  5. American Chemical Society - 240th national meeting - chemistry for preventing and combating disease: part 2.

    Science.gov (United States)

    Kibble, Alexandra

    2010-10-01

    The 240th National Meeting of the American Chemical Society, held in Boston, included topics covering new therapeutic research. This conference report highlights selected presentations on (S)-adenosylhomocysteine (AHCY) inhibitors for the treatment of Alzheimer's disease, 2,4-diphenyl-1H-imidazole analogs as cannabinoid CB2 agonists for the treatment of pain, checkpoint kinase 1 (Chk1) and Aurora kinase B as therapeutic targets for cancer treatment, pyridylmethylthio derivatives as VEGFR2 inhibitors, and Janus kinase 2 (JAK2) for the treatment of myeloproliferative disorders. Investigational drugs discussed include L-002259713 (Merck & Co), AZD-1480 (AstraZeneca), CYT-387 (YM Biosciences) and ruxolitinib (Incyte).

  6. The 2009 Lindau Nobel Laureate Meeting: Sir Harold Kroto, Chemistry 1996.

    Science.gov (United States)

    Kroto, Harold

    2010-01-01

    English Chemist Harold Kroto shared the 1996 Nobel Prize in Chemistry with Robert Curl and Richard Smalley for their discovery of Fullerenes (C(60;)), molecules composed completely of carbon (C(60;)) that form hollow spheres (also known as Buckyballs), tubes, or ellipsoids. These structures hold the potential for use in future technologies ranging from drug development and antimicrobial agents, to armor and superconductors. Harold Kroto was born in Wisbech, Cambridgeshire in 1939 and grew up in Bolton. Educated at Bolton School, he entered Sheffield University in 1958 to study Chemistry. During his time there he played tennis for the university team, illustrated the university's magazine covers, and played folk music with other students. Enjoying his time at Sheffield very much, he chose to stay on and complete a Ph.D. in Chemistry under Richard Dixon. Following graduation in 1964, Kroto went on to post doc at the National Research Council (NRC) in Ottowa, Canada where microwave spectroscopy became his specialty. After two years of study at the NRC he spent a year at Bell Laboratories. He then accepted a position as a tutorial fellow at the University of Sussex, where he was soon offered a permanent position. There, he applied his expertise in microwave spectroscopy to the field of astronomy and spent several fruitful years detecting long carbon chains in the interstellar medium. Upon hearing of the work of Richard Smalley at Rice, who developed a laser that could vaporize graphite, Kroto thought they could use Smalley's instrument to see carbon chains similar to those they had observed in interstellar matter. He suggested his idea for an experiment to Bob Curl, also at Rice. In 1985 he traveled to Rice to perform the experiment (and also to visit a half-price bookstore he'd heard about in Houston). Although he felt certain that the apparatus would create the carbon chains, the experiment revealed a totally unexpected result: the spontaneous formation of spherical

  7. Advances in radiation chemistry of polymers. Proceedings of a technical meeting

    International Nuclear Information System (INIS)

    The meeting on radiation effects on polymers was held at the Radiation Laboratory at the University of Notre Dame to review and discuss advances in the radiation processing of polymers. The trends in the basic research, research and development, and industrial applications were reported. The scope of more applied uses of irradiation involving polymers ranged from discussions of the curing of materials for dental applications, to the effects on polyolefins, the most broadly used class of polymers prevalent in industrial radiation processing, and to emerging interests in hydrogels, carbon fiber composites, heterogeneous mixtures based on material by-products (scrap plastic and wood fragments), grafted materials and materials for electronic uses. In addition, the emerging interests in the use of recently developed high power x ray systems for industrial use were presented. The document contains 12 individual papers, each of them was indexed and abstracted separately

  8. American Chemical Society - 240th national meeting - chemistry for preventing and combating disease: part 1.

    Science.gov (United States)

    Burt, Jessica

    2010-10-01

    The 240th National Meeting of the American Chemical Society, held in Boston, included topics covering new therapeutic research. This conference report highlights selected presentations on negative allosteric modulators of metabotropic glutamate receptor 5 (mGluR5) for the treatment of Parkinson's disease, BACE1 inhibitors and γ-secretase inhibitors for the prevention or treatment of Alzheimer's disease, opioid modulators for the treatment of reward disorders, SGLT2 inhibitors for the treatment of diabetes, backup compounds to the DPP-4 inhibitor sitagliptin (Januvia) for type 2 diabetes, and MCH R1 inhibitors for the treatment of obesity. Investigational drugs discussed include SCH-1359113 and SCH-1682496 (both Merck & Co), NGP-555 (NeuroGenetic Pharmaceuticals), ALKS-33 (Alkermes), dapagliflozin (Bristol-Myers Squibb/AstraZeneca) and GSK-882380 (GlaxoSmithKline).

  9. Complex interactions mediate the effects of fish farming on benthic chemistry within a region of Scotland.

    Science.gov (United States)

    Mayor, Daniel J; Solan, Martin

    2011-07-01

    Fish farms typically generate a localised gradient of both organic and inorganic pollutants in the underlying sediments. The factors governing the extent of such impacts remain poorly understood, particularly when multiple sites are considered. We used regression-type techniques to examine the drivers of sediment chemistry patterns around five Scottish fish farms that ranged in size (120-2106 tonnes) and fish species, but were located within farm illustrate that between-site variability can be high, even at this regional-scale. These effects must be accounted for when comparing the effects of fish farming at different locations. All measured chemical parameters declined rapidly as a function of distance from the cage edge, with the rate of decline depending on local current speeds. Only phosphorus concentrations increased directly with farm size. Increasing current speeds at farms carbon in the underlying sediments, whereas the opposite occurred at larger farms. The counterintuitive effect of current speed at farms above the threshold size suggests that the physical properties of the seabed at these locations favour the accumulation of organic wastes and/or that the underlying communities have a lower assimilative capacity. These imply that the environmental efficiency of fish farming activities may be further optimised by taking into account the interaction between current speed, substrate complexity and the functional characteristics of the benthos. Collectively, our analyses demonstrate that the fate of fish farm-derived wastes is complex and highlight the need for site-specific management techniques.

  10. Diversity of chemistry and excitation conditions in the high-mass star forming complex W33

    CERN Document Server

    Immer, K; König, C; Liu, H B; Menten, K M

    2014-01-01

    The object W33 is a giant molecular cloud that contains star forming regions at various evolutionary stages from quiescent clumps to developed H II regions. Since its star forming regions are located at the same distance and the primary material of the birth clouds is probably similar, we conducted a comparative chemical study to trace the chemical footprint of the different phases of evolution. We observed six clumps in W33 with the Atacama Pathfinder Experiment (APEX) telescope at 280 GHz and the Submillimeter Array (SMA) at 230 GHz. We detected 27 transitions of 10 different molecules in the APEX data and 52 transitions of 16 different molecules in the SMA data. The chemistry on scales larger than $\\sim$0.2 pc, which are traced by the APEX data, becomes more complex and diverse the more evolved the star forming region is. On smaller scales traced by the SMA data, the chemical complexity and diversity increase up to the hot core stage. In the H II region phase, the SMA spectra resemble the spectra of the pr...

  11. Electronic Transitions as a Probe of Tetrahedral versus Octahedral Coordination in Nickel(II) Complexes: An Undergraduate Inorganic Chemistry Experiment.

    Science.gov (United States)

    Filgueiras, Carlos A. L.; Carazza, Fernando

    1980-01-01

    Discusses procedures, theoretical considerations, and results of an experiment involving the preparation of a tetrahedral nickel(II) complex and its transformation into an octahedral species. Suggests that fundamental aspects of coordination chemistry can be demonstrated by simple experiments performed in introductory level courses. (Author/JN)

  12. Identification of Copper(II) Complexes in Aqueous Solution by Electron Spin Resonance: An Undergraduate Coordination Chemistry Experiment.

    Science.gov (United States)

    Micera, G.; And Others

    1984-01-01

    Background, procedures, and results are provided for an experiment which examines, through electron spin resonance spectroscopy, complex species formed by cupric and 2,6-dihydroxybenzoate ions in aqueous solutions. The experiment is illustrative of several aspects of inorganic and coordination chemistry, including the identification of species…

  13. Synthesis and Characterization of Europium(III) and Terbium(III) Complexes: An Advanced Undergraduate Inorganic Chemistry Experiment

    Science.gov (United States)

    Swavey, Shawn

    2010-01-01

    Undergraduate laboratories rarely involve lanthanide coordination chemistry. This is unfortunate in light of the ease with which many of these complexes are made and the interesting and instructive photophysical properties they entail. The forbidden nature of the 4f transitions associated with the lanthanides is overcome by incorporation of…

  14. Chemistry specificity of DNA-polycation complex salt response: a simulation study of DNA, polylysine and polyethyleneimine.

    Science.gov (United States)

    Antila, Hanne S; Härkönen, Marc; Sammalkorpi, Maria

    2015-02-21

    In this work, the chemistry specific stability determining factors of DNA-polycation complexes are examined by performing all-atom molecular dynamics simulations. To this end, we conduct a systematic variation of polycation line charge through polyethyleneimine (PEI) protonation and polycation chemistry via comparison with poly-l-lysine (PLL). Our simulations show that increasing line charge of the polycation alone does not lead to more salt tolerant complexes. Instead, the effective charge compensation by the polycation correlates with the increased stability of the complex against additional salt. The salt stability of PEI-DNA complexes also links to the proton sponge property of weak polycations, commonly assumed to be behind the effectivity of PEI as a gene delivery vector. Examination of the complexes reveals the mechanism behind this behaviour; more Cl(-) ions are attracted by the protonated complexes but, in contrast to the common depiction of the proton sponge behaviour, the ion influx does not cause swelling of the complex structure itself. However, PEI protonation leads to release of PEI while DNA remains tightly bound to the complex. Jointly, these findings shed light on the stability determining factors of DNA-polycation complexes, raise charge distribution as an important stability determining contributor, and indicate that the effectivity of PEI in gene delivery is likely to result from the freed PEI facilitating gene transfection. PMID:25607687

  15. Chemistry specificity of DNA-polycation complex salt response: a simulation study of DNA, polylysine and polyethyleneimine.

    Science.gov (United States)

    Antila, Hanne S; Härkönen, Marc; Sammalkorpi, Maria

    2015-02-21

    In this work, the chemistry specific stability determining factors of DNA-polycation complexes are examined by performing all-atom molecular dynamics simulations. To this end, we conduct a systematic variation of polycation line charge through polyethyleneimine (PEI) protonation and polycation chemistry via comparison with poly-l-lysine (PLL). Our simulations show that increasing line charge of the polycation alone does not lead to more salt tolerant complexes. Instead, the effective charge compensation by the polycation correlates with the increased stability of the complex against additional salt. The salt stability of PEI-DNA complexes also links to the proton sponge property of weak polycations, commonly assumed to be behind the effectivity of PEI as a gene delivery vector. Examination of the complexes reveals the mechanism behind this behaviour; more Cl(-) ions are attracted by the protonated complexes but, in contrast to the common depiction of the proton sponge behaviour, the ion influx does not cause swelling of the complex structure itself. However, PEI protonation leads to release of PEI while DNA remains tightly bound to the complex. Jointly, these findings shed light on the stability determining factors of DNA-polycation complexes, raise charge distribution as an important stability determining contributor, and indicate that the effectivity of PEI in gene delivery is likely to result from the freed PEI facilitating gene transfection.

  16. Water-stable fac-{TcO(3)}(+) Complexes - A new field of technetium chemistry

    OpenAIRE

    Braband, H.

    2011-01-01

    The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of ...

  17. 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)

  18. Evolution of multi-component anion relay chemistry (ARC): construction of architecturally complex natural and unnatural products.

    Science.gov (United States)

    Smith, Amos B; Wuest, William M

    2008-12-01

    Efficient construction of architecturally complex natural and unnatural products is the hallmark of organic chemistry. Anion relay chemistry (ARC)-a multi-component coupling protocol-has the potential to provide the chemist with a powerful synthetic tactic, enabling efficient, rapid elaboration of structurally complex scaffolds in a single operation with precise stereochemical control. The ARC tactic can be subdivided into two main classes, comprising the relay of negative charge either through bonds or through space, the latter with aid of a transfer agent. This review will present the current state of through-space anion relay, in conjunction with examples of natural and unnatural product syntheses that illustrate the utility of this synthetic method. PMID:19030533

  19. A 'complex' of brain metabolites distinguish altered chemistry in the cingulate cortex of episodic migraine patients.

    Science.gov (United States)

    Becerra, L; Veggeberg, R; Prescot, A; Jensen, J E; Renshaw, P; Scrivani, S; Spierings, E L H; Burstein, R; Borsook, D

    2016-01-01

    Despite the prevalence of migraine, the pathophysiology of the disease remains unclear. Current understanding of migraine has alluded to the possibility of a hyperexcitable brain. The aim of the current study is to investigate human brain metabolite differences in the anterior cingulate cortex (ACC) during the interictal phase in migraine patients. We hypothesized that there may be differences in levels of excitatory neurotransmitters and/or their derivatives in the migraine cohort in support of the theory of hyperexcitability in migraine. 2D J-resolved proton magnetic resonance spectroscopy ((1)H-MRS) data were acquired on a 3 Tesla (3 T) MRI from a voxel placed over the ACC of 32 migraine patients (MP; 23 females, 9 males, age 33 ± 9.6 years) and 33 healthy controls (HC; 25 females, 8 males, age 32 ± 9.6 years). Amplitude correlation matrices were constructed for each subject to evaluate metabolite discriminability. ProFit-estimated metabolite peak areas were normalized to a water reference signal to assess subject differences. The initial analysis of variance (ANOVA) was performed to test for group differences for all metabolites/creatine (Cre) ratios between healthy controls and migraineurs but showed no statistically significant differences. In addition, we used a multivariate approach to distinguish migraineurs from healthy subjects based on the metabolite/Cre ratio. A quadratic discriminant analysis (QDA) model was used to identify 3 metabolite ratios sufficient to minimize minimum classification error (MCE). The 3 selected metabolite ratios were aspartate (Asp)/Cre, N-acetyl aspartate (NAA)/Cre, and glutamine (Gln)/Cre. These findings are in support of a 'complex' of metabolite alterations, which may underlie changes in neuronal chemistry in the migraine brain. Furthermore, the parallel changes in the three-metabolite 'complex' may confer more subtle but biological processes that are ongoing. The data also support the current theory that the

  20. Divergent Coordination Chemistry: Parallel Synthesis of [2×2] Iron(II) Grid-Complex Tauto-Conformers.

    Science.gov (United States)

    Schäfer, Bernhard; Greisch, Jean-François; Faus, Isabelle; Bodenstein, Tilmann; Šalitroš, Ivan; Fuhr, Olaf; Fink, Karin; Schünemann, Volker; Kappes, Manfred M; Ruben, Mario

    2016-08-26

    The coordination of iron(II) ions by a homoditopic ligand L with two tridentate chelates leads to the tautomerism-driven emergence of complexity, with isomeric tetramers and trimers as the coordination products. The structures of the two dominant [Fe(II) 4 L4 ](8+) complexes were determined by X-ray diffraction, and the distinctness of the products was confirmed by ion-mobility mass spectrometry. Moreover, these two isomers display contrasting magnetic properties (Fe(II) spin crossover vs. a blocked Fe(II) high-spin state). These results demonstrate how the coordination of a metal ion to a ligand that can undergo tautomerization can increase, at a higher hierarchical level, complexity, here expressed by the formation of isomeric molecular assemblies with distinct physical properties. Such results are of importance for improving our understanding of the emergence of complexity in chemistry and biology.

  1. Deciphering the Complex Chemistry of Deep-Ocean Particles Using Complementary Synchrotron X-ray Microscope and Microprobe Instruments.

    Science.gov (United States)

    Toner, Brandy M; German, Christopher R; Dick, Gregory J; Breier, John A

    2016-01-19

    The reactivity and mobility of natural particles in aquatic systems have wide ranging implications for the functioning of Earth surface systems. Particles in the ocean are biologically and chemically reactive, mobile, and complex in composition. The chemical composition of marine particles is thought to be central to understanding processes that convert globally relevant elements, such as C and Fe, among forms with varying bioavailability and mobility in the ocean. The analytical tools needed to measure the complex chemistry of natural particles are the subject of this Account. We describe how a suite of complementary synchrotron radiation instruments with nano- and micrometer focusing, and X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) capabilities are changing our understanding of deep-ocean chemistry and life. Submarine venting along mid-ocean ridges creates hydrothermal plumes where dynamic particle-forming reactions occur as vent fluids mix with deep-ocean waters. Whether plumes are net sources or sinks of elements in ocean budgets depends in large part on particle formation, reactivity, and transport properties. Hydrothermal plume particles have been shown to host microbial communities and exhibit complex size distributions, aggregation behavior, and composition. X-ray microscope and microprobe instruments can address particle size and aggregation, but their true strength is in measuring chemical composition. Plume particles comprise a stunning array of inorganic and organic phases, from single-crystal sulfides to poorly ordered nanophases and polymeric organic matrices to microbial cells. X-ray microscopes and X-ray microprobes with elemental imaging, XAS, and XRD capabilities are ideal for investigating these complex materials because they can (1) measure the chemistry of organic and inorganic constituents in complex matrices, usually within the same particle or aggregate, (2) provide strong signal-to-noise data with exceedingly small

  2. Computational Chemistry to the Rescue: Modern Toolboxes for the Assignment of Complex Molecules by GIAO NMR Calculations.

    Science.gov (United States)

    Grimblat, Nicolas; Sarotti, Ariel M

    2016-08-22

    The calculations of NMR properties of molecules using quantum chemical methods have deeply impacted several branches of organic chemistry. They are particularly important in structural or stereochemical assignments of organic compounds, with implications in total synthesis, stereoselective reactions, and natural products chemistry. In studying the evolution of the strategies developed to support (or reject) a structural proposal, it becomes clear that the most effective and accurate ones involve sophisticated procedures to correlate experimental and computational data. Owing to their relatively high mathematical complexity, such calculations (CP3, DP4, ANN-PRA) are often carried out using additional computational resources provided by the authors (such as applets or Excel files). This Minireview will cover the state-of-the-art of these toolboxes in the assignment of organic molecules, including mathematical definitions, updates, and discussion of relevant examples.

  3. Mathematical Modeling of Complex Reaction Systems for Computer-Aided Control and its Illustration on Atmospheric Chemistry

    Science.gov (United States)

    Amiryan, A.

    2015-12-01

    Modeling of sequential process has its own importance in Atmospheric Chemistry. Numerical calculations which allow to predict separate stages and components of chemical reaction make possible the reaction management, such is the new and perspective direction in chemical researches. Chemical processes basically pass multiple simple stages where various atoms and radicals participate. The complex chain of chemical reactionary systems complicates their research and the research is impossible without new methods of mathematical simulation and high technologies which allow not only to explain results of experiments but also to predict dynamics of processes. A new program package is suggested for solving research problems of chemical kinetics. The program is tested on different illustrative examples on Atmospheric Chemistry and installed in various scientific and educational institutions.

  4. Interstellar Chemistry Gets More Complex With New Charged-Molecule Discovery

    Science.gov (United States)

    2007-07-01

    Astronomers using data from the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT) have found the largest negatively-charged molecule yet seen in space. The discovery of the third negatively-charged molecule, called an anion, in less than a year and the size of the latest anion will force a drastic revision of theoretical models of interstellar chemistry, the astronomers say. Molecule formation Formation Process of Large, Negatively-Charged Molecule in Interstellar Space CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for page of graphics and detailed information "This discovery continues to add to the diversity and complexity that is already seen in the chemistry of interstellar space," said Anthony J. Remijan of the National Radio Astronomy Observatory (NRAO). "It also adds to the number of paths available for making the complex organic molecules and other large molecular species that may be precursors to life in the giant clouds from which stars and planets are formed," he added. Two teams of scientists found negatively-charged octatetraynyl, a chain of eight carbon atoms and one hydrogen atom, in the envelope of gas around an old, evolved star and in a cold, dark cloud of molecular gas. In both cases, the molecule had an extra electron, giving it a negative charge. About 130 neutral and about a dozen positively-charged molecules have been discovered in space, but the first negatively-charged molecule was not discovered until late last year. The largest previously-discovered negative ion found in space has six carbon atoms and one hydrogen atom. "Until recently, many theoretical models of how chemical reactions evolve in interstellar space have largely neglected the presence of anions. This can no longer be the case, and this means that there are many more ways to build large organic molecules in cosmic environments than have been explored," said Jan M. Hollis of NASA's Goddard Space Flight Center (GSFC). Ultraviolet light from stars can

  5. Solventless and One-Pot Synthesis of Cu(II) Phthalocyanine Complex: A Green Chemistry Experiment

    Science.gov (United States)

    Sharma, R. K.; Sharma, Chetna; Sidhwani, Indu Tucker

    2011-01-01

    With the growing awareness of green chemistry, it is increasingly important for students to understand this concept in the context of laboratory experiments. Although microwave-assisted organic synthesis has become a common and invaluable technique in recent years, there have been few procedures published for microwave-assisted inorganic synthesis…

  6. American Chemical Society--238th National Meeting & Exposition. Developments in medicinal chemistry: part 2. 16-20 August 2009, Washington DC, USA.

    Science.gov (United States)

    Gater, Deborah; Macauley, Donald

    2009-10-01

    The 238th National Meeting and Exposition of the American Chemical Society, held in Washington DC, included topics covering new compounds and developments in the field of medicinal chemistry. This conference report highlights selected presentations on inhibitors of PARP, a heme oxygenase 1 (HO-1) inhibitor, NS3 protease inhibitors, a corticotrophin-releasing factor 1 (CRF-1) receptor antagonist, a cannabinoid receptor antagonist, diacylglycerol acyltransferase inhibitors, cathepsin and chymase receptor inhibitors, and MAPK inhibitors. Investigational drugs discussed include veliparib (Abbott Laboratories), MK-4827 (Merck & Co Inc), OB-24 (Osta Biotechnologies), BMS-339, BMS-764459, BMS-812204 and BMS-640994 (all Bristol-Myers Squibb Co), and JNJ-10311795 (Johnson & Johnson).

  7. Coordination chemistry of sugar-phosphate complexes with palladium(II), rhenium(V) and zinc(II)

    Energy Technology Data Exchange (ETDEWEB)

    Steinborn, Christian Martin

    2013-05-21

    As described before, some studies dealing with coordination chemistry of sugar phosphates are available but no analogous complexes of Zn{sup II} have been investigated yet. The primary goal of this work is, therefore, to fill this gap. In order to stay close to the active sites of enzymes such as class-II-aldolase, the simple metal fragment Zn{sup II}(dien) is used. NMR spectroscopy is used primarily as analytical method since it enables the investigation of both complex equilibria in solution and pH dependence of metal-binding sites. Since this approach is challenging due to the fast metal-ligand exchange and the absence of CIS values, it is necessary to improve the significance of NMR data collected from sugar-phosphate complexes with Zn{sup II}. Hence, further experiments are performed with molecules similar to sugar phosphates such as reducing and methylated sugars or polyols. Beside NMR spectroscopy, crystal-structure analysis will be used to get more detailed information about the binding pattern of the complexes. Additionally, sugar-phosphate complexes of Pd{sup II} are investigated. Further experiments are conducted, on the one hand, to synthesise more sugarphosphate complexes with ReVON2 fragments, and, on the other hand, to grow crystals confirming the theory about mixed sugar-core-phosphate chelation.

  8. Coordination Chemistry of Disilylated Stannylenes with Group 10 d10 Transition Metals: Silastannene vs Stannylene Complexation

    OpenAIRE

    Arp, Henning; Marschner, Christoph; Baumgartner, Judith; Zark, Patrick; Müller, Thomas

    2013-01-01

    The coordination behavior of disilylated stannylenes toward zerovalent group 10 transition metal complexes was studied. This was accomplished by reactions of PEt3 adducts of disilylated stannylenes with zerovalent group 10 transition metal complexes. The thus obtained products differed between the first row example nickel and its heavier congeners. While with nickel stannylene complex formation was observed, coordination of the stannylenes to palladium and platinum compounds led to unusual si...

  9. Heteroskorpionate Ligands In Coordination ChemistryComplexes Relevant To Hydrogenation Catalysis, Olefine Epoxidation, And Inhibitor Studies

    OpenAIRE

    Tampier, Stefan

    2012-01-01

    This work focuses on (i) the syntheses and characterisations of various ruthenium(II) complexes bearing the bdmpza ligand, (ii) complexes based on the new bis(3,5-di-tert-butylpyrazol-1-yl)dithioacetato ligand, (iii) complexes based on bispyrazolylacetate esters, and (iv) the syntheses and characteristics of ferrocenyl-substituted ligands derived from bispyrazolylacetic acid and related chelating ligands. Chapter 3.1.2 outlines principle substitution reactions of [Ru(bdmpza)Cl(PPh3)2] (1) [bd...

  10. Plutonium(IV) complexation by diglycolamide ligands - coordination chemistry insight into TODGA-based actinide separations

    NARCIS (Netherlands)

    Reilly, S.D.; Gaunt, A.J.; Scott, B.L.; Modolo, G.; Iqbal, M.; Verboom, W.; Sarsfield, M.J.

    2012-01-01

    Complexation of Pu(IV) with TMDGA, TEDGA, and TODGA diglycolamide ligands was followed by vis-NIR spectroscopy. A crystal structure determination reveals that TMDGA forms a 1:3 homoleptic Pu(IV) complex with the nitrate anions forced into the outer coordination sphere

  11. PREFACE: 4th National Meeting in Chaos, Complex System and Time Series

    Science.gov (United States)

    Raúl Hernández Montoya, Alejandro; Hernández Lemus, Enrique; Rubén Luévano Enríquez, José; Rodríguez Achach, Manuel Enrique; Vargas Madrazo, Carlos Ernesto

    2013-12-01

    The fourth edition of the National Meeting on Chaos, Complex Systems and Time Series (NMCCSTS4), or in Spanish 4a. Reunión Nacional de Caos, Sistemas Complejos y Series de Tiempo, was held from 29 November to 2 December 2011 in the University of Veracruz (Universidad Veracruzana), Campus Xalapa, at Xalapa Veracruz, México, in the beautiful House of the Lake (Casa del Lago), a late XIX century former textile factory situated in the edge of an also ancient former dam, currently a park containing three small lakes, very emblematic of Xalapa, City, the capital of the state of Veracruz, México. The previous editions of this meeting, were held in Mérida (2006), Pachuca (2008) and Puebla (2009). A clear uptrend is observed in the number of participants in this academic event from all Universities of México and abroad, going from about 15 participants in the first meeting to more than 90 in the last one. On this occasion, about 90 participants from three countries attended our event, where 29 papers (10 master lectures from top recognized national and international leaders in the fields of complexity, and 19 invited papers), one course for students and 42 posters were presented. A look at the scientific program of the NMCCSTS4, allows us to appreciate the wide range of topics and recent advances that were covered during our event; topics and recent results in the areas of biology, econophysics, sociophysics, genomics and bioinformatics, complex networks, thermodynamics, etc, were presented and discussed rigorously in a friendly, dynamical and informal atmosphere. Also, on this occasion, we celebrated Professor Miguel Angel Jiménez Montaño, for his very distinguished academic career throughout more that 50 years and as a founding member of the Faculty of Physics and AI of University of Veracruz. Prizes were awarded for the best poster presentations. The winner was Porfirio Toledo, from Faculty of Mathematics, University of Veracruz (Game theory to characterize

  12. From simple to complex prebiotic chemistry in a carbon-rich universe

    Science.gov (United States)

    Lage, C.; Janot-Pacheco, E.; Domiciano de Souza, A.; Suárez, O.; Bendjoya, P.; Gadotti, D. A.

    2012-09-01

    It is well known that the main components of important biomolecules are quite common not only in the Solar System, but also in other planetary systems and in the Galactic ISM. The ubiquitous presence of C in the Universe and the unique carbon chemical properties and carbon bonding thermodynamics supports the spontaneous self-replication of monomers into larger polymers, yielding the formation of large molecules. The detection of an ever increasing number of organic molecules in the interstellar medium (ISM) by radio-telescopes and chemical analysis of meteorites boosted astrochemical theories on radiation-induced chemistry, supported by laboratory experiments. In this scenario of exogenous origin of carbon compounds, polyaromatic hydrocarbons (PAHs) may represent a resilient way of accumulating carbon as a robust cosmic reservoir. Consisting of a family of compounds with fused aromatic rings, the abundances of its larger members (50-100 carbon atoms) were estimated to be on top scores just after H2 and CO. PAHs have been detected in the ISM, in star-forming regions, ~14% of low-mass premainsequence stars, and, remarkably, in some 54% of intermediate mass stars. They have also been detected by SPITZER in distant galaxies up to z = 3. PAHs were promptly photolysed into a family of radicals if exposed to UV and oxygen-bearing molecules in laboratory. The presence of oxygenbearing molecules was shown in the laboratory to bring aromatic rings into an unstable chemistry leading to the production of e.g. alcohols, ketones and ether radicals. It has already been observed that carbon-and oxygen-rich stellar envelopes give rise to richer carbon chemistry. It appears very tempting to think that key prebiotic fragments should appear along planetary formation as C-O reaction byproducts such as methanol (CH3OH), formaldehyde (H2CO) and also simpler hydrocarbons as methyl acetylene (CH3CCH). Under an Astrobiology perspective it is plausible to map PAHs and oxygen compounds

  13. Chemistry of Platinum and Palladium Metal Complexes in Homogeneous and Heterogeneous Catalysis: A Mini Review

    Directory of Open Access Journals (Sweden)

    Mehrban Ashiq

    2013-04-01

    Full Text Available Transition metal complexes of platinum and palladium are most widely used in catalysis. Many synthetic reactions have been carried out with such complexes (used as a catalyst which have specifically polymer ligands, through hydrosilylation, acetoxylation, hydrogenation, hydro-formylation, oligo-merisation and polymerization. Almost many platinum and palladium catalysts are heterogeneous in nature i.e. the reaction taking place on a solid surface. Now from few years homogeneous catalysts which are completely soluble in the liquid phase reactant, has acknowledged too much attention, yet having small industrial applications, mainly due to the striving of platinum and palladium complexes separation from the catalytic products. More recently a transitional type of platinum and palladium catalysts have been synthesized through attachment of the activated transition metal complexes on the surface of polymer support particularly insoluble which has been establish to offer encouraging new collection of catalysts for effective research on synthesis. Many of such complexes will be based on the palladium and platinum metals group. The major objective of this review is to inaugurate the relationship among the reactivity’s of homogeneous platinum and palladium complexes and heterogeneous complexes of these metals (those bonded to the surface of metals.

  14. Design of stereoelectronically promoted super lewis acids and unprecedented chemistry of their complexes.

    Science.gov (United States)

    Foroutan-Nejad, Cina; Vicha, Jan; Marek, Radek

    2014-09-01

    A new family of stereoelectronically promoted aluminum and scandium super Lewis acids is introduced on the basis of state-of-the-art computations. Structures of these molecules are designed to minimize resonance electron donation to central metal atoms in the Lewis acids. Acidity of these species is evaluated on the basis of their fluoride-ion affinities relative to the antimony pentafluoride reference system. It is demonstrated that introduced changes in the stereochemistry of the designed ligands increase acidity considerably relative to Al and Sc complexes with analogous monodentate ligands. The high stability of fluoride complexes of these species makes them ideal candidates to be used as weakly coordinating anions in combination with highly reactive cations instead of conventional Lewis acid-fluoride complexes. Further, the interaction of all designed molecules with methane is investigated. All studied acids form stable pentavalent-carbon complexes with methane. In addition, interactions of the strongest acid of this family with very weak bases, namely, H2, N2, carbon oxides, and noble gases were investigated; it is demonstrated that this compound can form considerably stable complexes with the aforementioned molecules. To the best of our knowledge, carbonyl and nitrogen complexes of this species are the first hypothetical four-coordinated carbonyl and nitrogen complexes of aluminum. The nature of bonding in these systems is studied in detail by various bonding analysis approaches. PMID:25055748

  15. Design of stereoelectronically promoted super lewis acids and unprecedented chemistry of their complexes.

    Science.gov (United States)

    Foroutan-Nejad, Cina; Vicha, Jan; Marek, Radek

    2014-09-01

    A new family of stereoelectronically promoted aluminum and scandium super Lewis acids is introduced on the basis of state-of-the-art computations. Structures of these molecules are designed to minimize resonance electron donation to central metal atoms in the Lewis acids. Acidity of these species is evaluated on the basis of their fluoride-ion affinities relative to the antimony pentafluoride reference system. It is demonstrated that introduced changes in the stereochemistry of the designed ligands increase acidity considerably relative to Al and Sc complexes with analogous monodentate ligands. The high stability of fluoride complexes of these species makes them ideal candidates to be used as weakly coordinating anions in combination with highly reactive cations instead of conventional Lewis acid-fluoride complexes. Further, the interaction of all designed molecules with methane is investigated. All studied acids form stable pentavalent-carbon complexes with methane. In addition, interactions of the strongest acid of this family with very weak bases, namely, H2, N2, carbon oxides, and noble gases were investigated; it is demonstrated that this compound can form considerably stable complexes with the aforementioned molecules. To the best of our knowledge, carbonyl and nitrogen complexes of this species are the first hypothetical four-coordinated carbonyl and nitrogen complexes of aluminum. The nature of bonding in these systems is studied in detail by various bonding analysis approaches.

  16. Evolved stars as complex chemical laboratories - the quest for gaseous chemistry

    Science.gov (United States)

    Katrien Els Decin, Leen

    2015-08-01

    At the end of their life, most stars lose a large fraction of their mass through a stellar wind. The stellar winds of evolved (super)giant stars are the dominant suppliers for the pristine building blocks of the interstellar medium (ISM). Crucial to the understanding of the chemical life cycle of the ISM is hence a profound insight in the chemical and physical structure governing these stellar winds.These winds are really unique chemical laboratories in which currently more than 70 different molecules and 15 different dust species are detected. Several chemical processes such as neutral-neutral and ion-molecule gas-phase reactions, dust nucleation and growth, and photo-processes determine the chemical content of these winds. However, gas-phase and dust-nucleation chemistry for astronomical environments still faces many challenges. One should realize that only ˜15% of the rate coefficients for gas-phase reactions considered to occur in (inter/circum)stellar regions at temperatures (T) below 300K have been subject to direct laboratory determinations and that the temperature dependence of the rate constants is often not known; only ˜2% have rate constants at Tstars. In this presentation, I will demonstrate the need for accurate temperature-dependent gas-phase reaction rate constants and will present our new laboratory equipment built to measure the rate constants for species key in stellar wind chemistry. Specifically, we aim to obtain the rate constants of reactions involving silicon- and sulphur bearing species and HCCO for 30

  17. Evaluation of phase chemistry and petrochemical aspects of Samchampi–Samteran differentiated alkaline complex of Mikir Hills, northeastern India

    Indian Academy of Sciences (India)

    Abhishek Saha; Sohini Ganguly; Jyotisankar Ray; Nilanjan Chaterjee

    2010-10-01

    The Samchampi –Samteran alkaline complex occurs as a plug-like pluton within the Precambrian granite gneisses of Mikir Hills,Assam,northeastern India and it is genetically related to Sylhet Traps.The intrusive complex is marked by dominant development of syenite within which ijolite – melteigite suite of rocks is emplaced with an arcuate outcrop pattern.Inliers of alkali pyroxenite and alkali gabbro occur within this ijolite –melteigite suite of rocks.The pluton is also traversed by younger intrusives of nepheline syenite and carbonatite.Development of sporadic,lumpy magnetite ore bodies is also recorded within the pluton.Petrographic details of the constituent lithomembers of the pluton have been presented following standard nomenclatorial rules.Overall pyroxene compositions range from diopside to aegirine augite while alkali feldspars are typically orthoclase and plagioclase in syenite corresponds to oligoclase species.Phase chemistry of nepheline is suggestive of Na-rich alkaline character of the complex.Biotite compositions are typically restricted to a uniform compositional range and they belong to ‘biotite ’field in the relevant classification scheme.Garnets (developed in syenite and melteigite)typically tend to be Ti-rich andradite,which on a closer scan can be further designated as melanites.Opaque minerals mostly correspond to magnetite.Use of Lindsley ’s pyroxene thermometric method suggests an equilibration temperature from ∼450°–600°C for melteigite/alkali gabbro and ∼400° C for syenite.Critical assessment of other thermometric methods reveals a temperature of equilibration of ∼700°–1350°C for ijolite –melteigite suite of rocks in contrast to a relatively lower equilibration temperature of ∼600° C for syenite. Geobarometric data based on pyroxene chemistry yield an equilibration pressure of 5.32 –7.72 kb for ijolite,melteigite,alkali pyroxenite,alkali gabbro and nepheline syenite.The dominant syenite member of the

  18. Ruthenium(II) multi carboxylic acid complexes: chemistry and application in dye sensitized solar cells.

    Science.gov (United States)

    Shahroosvand, Hashem; Nasouti, Fahimeh; Sousaraei, Ahmad

    2014-04-01

    Novel ruthenium multi carboxylic complexes (RMCCs) have been synthesized by using ruthenium nitrosyl nitrate, 1,2,4,5-benzenetetracarboxylic acid (H4btec) and 4,7-diphenyl-1,10-phenanthroline (BPhen) as photosensitizers for titanium dioxide semiconductor solar cells. The complexes were characterized by (1)H-NMR, FT-IR, UV-Vis, ICP and CHN analyses. The reaction details and features were then described. SEM analysis revealed that the penetration of dyes into the pores of the nanocrystalline TiO2 surface was improved by increasing the number of btec units. The solar energy to electricity conversion efficiency of complexes shows that the number of attached carboxylates on a dye has an influence on the photoelectrochemical properties of the dye-sensitized electrode. An incident photon-to-current conversion efficiency (IPCE) of 13% at 510 nm was obtained for ruthenium complexes with three btec units. PMID:24500312

  19. Chemistry of Iron N -heterocyclic carbene complexes: Syntheses, structures, reactivities, and catalytic applications

    KAUST Repository

    Riener, Korbinian

    2014-05-28

    Iron is the most abundant transition metal in Earth\\'s crust. It is relatively inexpensive, not very toxic, and environmentally benign. Undoubtedly, due to the involvement in a multitude of biological processes, which heavily rely on the rich functionalities of iron-containing enzymes, iron is one of the most important elements in nature. Additionally, three-coordinate iron complexes have been reported during the past several years. In this review, the mentioned iron NHC complexes are categorized by their main structure and reactivity attributes. Thus, monocarbene and bis-monocarbene complexes are presented first. This class is subdivided into carbonyl, nitrosyl, and halide compounds followed by a brief section on other, more unconventional iron NHC motifs. Subsequently, donor-substituted complexes bearing bi-, tri-, tetra-, or even pentadentate ligands and further pincer as well as scorpionato motifs are described.

  20. Chemistry of Platinum and Palladium Metal Complexes in Homogeneous and Heterogeneous Catalysis: A Mini Review

    OpenAIRE

    Mehrban Ashiq; Fareeha Mukhtar; Sineen Bari; Muhammad Danish; Muhammad Ali Mohsin

    2013-01-01

    Transition metal complexes of platinum and palladium are most widely used in catalysis. Many synthetic reactions have been carried out with such complexes (used as a catalyst) which have specifically polymer ligands, through hydrosilylation, acetoxylation, hydrogenation, hydro-formylation, oligo-merisation and polymerization. Almost many platinum and palladium catalysts are heterogeneous in nature i.e. the reaction taking place on a solid surface. Now from few years homogeneou...

  1. Unified Microscopic-Macroscopic Monte Carlo Simulations of Complex Organic Molecule Chemistry in Cold Cores

    OpenAIRE

    Chang, Qiang; Herbst, Eric

    2016-01-01

    The recent discovery of methyl formate and dimethyl ether in the gas phase of cold cores with temperatures as cold as 10 K challenges our previous astrochemical models concerning the formation of complex organic molecules. The strong correlation between the abundances and distributions of methyl formate and dimethyl ether further shows that current astrochemical models may be missing important chemical processes in cold astronomical sources. We investigate a scenario in which complex organic ...

  2. Host-guest chemistry of Cu2+/Histidine complexes in molecular sieves

    OpenAIRE

    Mesu, Jan Gijsbert

    2005-01-01

    The high activity and selectivity of enzymes have inspired many scientists to study the structure and working mechanism of bio-molecular complexes. Also in the catalysis community this subject is of topical interest, as it may provide inspiration for the development of a new generation of bio-inspired catalyst materials. Functionalization of inorganic substrates, such as zeolites, with transition metal ion (TMI) complexes offers the possibility to design new materials with a high potential to...

  3. Conformer Hunting: An Open-Ended Computational Chemistry Exercise That Expresses Real-World Complexity and Student Forethought

    Science.gov (United States)

    Lipkowitz, Kenny B.; Robertson, Daniel

    2000-02-01

    A computational chemistry project suitable for both graduate and undergraduate classes has been developed, tested, and implemented successfully over the course of 10 years. In this project we ask students the following simple question: "Which conformer searching strategy in Spartan is the best?" To answer this question the students need to develop a working definition of what "best" means within the context of the project, design their own experiments that can address that question most suitably, carry out the calculations to derive a compelling answer, and then write their results in the form of a research paper. In addition to teaching students about potential energy surfaces, molecular modeling techniques, and stereochemistry, the pedagogical advantages of this computational chemistry exercise compared to others published in this Journal are that it (i) requires a significant amount of student forethought in addition to afterthought by forcing students to design their own experiments, (ii) demonstrates real-world levels of complexity by using molecules having multiple rotatable bonds, (iii) allows for student creativity that is missing in most other published exercises, (iv) focuses on writing in the curriculum.

  4. Accurate Reproduction of 161 Small-Molecule Complex Crystal Structures using the EUDOC Program: Expanding the Use of EUDOC to Supramolecular Chemistry

    OpenAIRE

    Wang, Qi; Pang, Yuan-Ping

    2007-01-01

    EUDOC is a docking program that has successfully predicted small-molecule-bound protein complexes and identified drug leads from chemical databases. To expand the application of the EUDOC program to supramolecular chemistry, we tested its ability to reproduce crystal structures of small-molecule complexes. Of 161 selected crystal structures of small-molecule guest-host complexes, EUDOC reproduced all these crystal structures with guest structure mass-weighted root mean square deviations (mwRM...

  5. 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.

  6. Bimetallic ruthenium–tin chemistry: Synthesis and molecular structure of arene ruthenium complexes containing trichlorostannyl ligands

    OpenAIRE

    Therrien, Bruno; Thai, Trieu-Tien; Freudenreich, Julien; Süss-Fink, Georg; Shapovalov, Sergey S.; Pasynskii, Alexandr A.; Plasseraud, Laurent

    2012-01-01

    A series of neutral, anionic and cationic arene ruthenium complexes containing the trichlorostannyl ligand have been synthesised from SnCl2 and the corresponding arene ruthenium dichloride dimers [(η6-arene)Ru(μ2-Cl)Cl]2 (arene = C6H6, PriC6H4Me). While the reaction with triphenylphosphine and stannous chloride only gives the neutral mono(trichlorostannyl) complexes [(η6-C6H6)Ru(PPh3)(SnCl3)Cl] (1) and [(η6-PriC6H4Me)Ru(PPh3)(SnCl3)Cl] (2), the neutral di(trichlorostannyl) complex [(η6-PriC6H...

  7. Fighting Fenton Chemistry: A Highly Active Iron(III) Tetracarbene Complex in Epoxidation Catalysis.

    Science.gov (United States)

    Kück, Jens W; Anneser, Markus R; Hofmann, Benjamin; Pöthig, Alexander; Cokoja, Mirza; Kühn, Fritz E

    2015-12-01

    Organometallic Fe complexes with exceptionally high activities in homogeneous epoxidation catalysis are reported. The compounds display Fe(II) and Fe(III) oxidation states and bear a tetracarbene ligand. The more active catalyst exhibits activities up to 183 000 turnovers per hour at room temperature and turnover numbers of up to 4300 at -30 °C. For the Fe(III) complex, a decreased Fenton-type reactivity is observed compared with Fe(II) catalysts reported previously as indicated by a substantially lower H2 O2 decomposition and higher (initial) turnover frequencies. The dependence of the catalyst performance on the catalyst loading, substrate, water addition, and the oxidant is investigated. Under all applied conditions, the advantageous nature of the use of the Fe(III) complex is evident.

  8. The synthesis and unexpected solution chemistry of thermochromic carborane-containing osmium half-sandwich complexes.

    Science.gov (United States)

    Pitto-Barry, Anaïs; South, Amy; Rodger, Alison; Barry, Nicolas P E

    2016-01-28

    The functionalisation of the 16-electron complex [Os(η(6)-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)] (1) with a series of Lewis bases to give the 18-electron complexes of general formula [Os(η(6)-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)(L)] (L = pyridine (2), 4-dimethylaminopyridine (3), 4-cyanopyridine (4), 4-methoxypyridine (5), pyrazine (6), pyridazine (7), 4,4'-bipyridine (8) and triphenylphosphine (9)) is reported. All 18-electron complexes are in equilibrium in solution with the 16-electron precursor, and thermochromic properties are observed in some cases (2, 3, 5, 8, and 9). The binding constants and Gibbs free energies of the equilibria are determined using UV-visible titrations and their stabilities investigated. Synthetic routes for forcing the formation of the 18-electron species are proposed, and analytical methods to characterise the equilibria are described. PMID:26700880

  9. Bulky N-Phosphino-Functionalized N-Heterocyclic Carbene Ligands: Synthesis, Ruthenium Coordination Chemistry, and Ruthenium Alkylidene Complexes for Olefin Metathesis.

    Science.gov (United States)

    Brown, Christopher C; Rominger, Frank; Limbach, Michael; Hofmann, Peter

    2015-11-01

    Ruthenium chemistry and applications in catalytic olefin metathesis based on N-phosphino-functionalized N-heterocyclic carbene ligands (NHCPs) are presented. Alkyl NHCP Ru coordination chemistry is described, and access to several potential synthetic precursors for ruthenium alkylidene complexes is outlined, incorporating both trimethylsilyl and phenyl alkylidenes. The Ru alkylidene complexes are evaluated as potential olefin metathesis catalysts and were shown to behave in a latent fashion. They displayed catalytic activity at elevated temperatures for both ring closing metathesis and ring opening metathesis polymerization. PMID:26479425

  10. Bulky N-Phosphino-Functionalized N-Heterocyclic Carbene Ligands: Synthesis, Ruthenium Coordination Chemistry, and Ruthenium Alkylidene Complexes for Olefin Metathesis.

    Science.gov (United States)

    Brown, Christopher C; Rominger, Frank; Limbach, Michael; Hofmann, Peter

    2015-11-01

    Ruthenium chemistry and applications in catalytic olefin metathesis based on N-phosphino-functionalized N-heterocyclic carbene ligands (NHCPs) are presented. Alkyl NHCP Ru coordination chemistry is described, and access to several potential synthetic precursors for ruthenium alkylidene complexes is outlined, incorporating both trimethylsilyl and phenyl alkylidenes. The Ru alkylidene complexes are evaluated as potential olefin metathesis catalysts and were shown to behave in a latent fashion. They displayed catalytic activity at elevated temperatures for both ring closing metathesis and ring opening metathesis polymerization.

  11. American Chemical Society--238th National Meeting & Exposition. Developments in medicinal chemistry: part 1. 16-20 August 2009, Washington DC, USA.

    Science.gov (United States)

    Gater, Deborah; Macauley, Donald

    2009-10-01

    The 238th National Meeting and Exposition of the American Chemical Society, held in Washington DC, included topics covering new compounds and developments in the field of medicinal chemistry. This conference report highlights selected presentations on a novel KV1.5 blocker, a state-dependent CaV2.2 antagonist, therapeutic uses of macrocycles, a novel P2X7 antagonist, developments using the StaR technology platform, the optimization of a neuropeptide S receptor antagonist, and type 1 glycine transport modulators. Investigational drugs discussed include WYE-160020 (Wyeth), Trox-1 (Neuromed Pharmaceuticals Inc), ulimorelin (Tranzyme Pharma Inc), E-32224 (Ensemble Discovery Corp) and PF-03463275 (Pfizer Inc); the discontinued compound AZD-9056 is also highlighted.

  12. Chemistry of the Arroyo Marincho complex and Granodiorita of the Arroyo Grande. Part II. (Uruguay)

    International Nuclear Information System (INIS)

    Mineralogical and chemical studies as well as thermodynamic conditions evaluation are able to localize several stabilized curves of the ferromagnese minerals in the Marincho complex ands the Arroyo Grande. The geochemical and thermodynamic characteristics has allowed to drive different evolutive models.

  13. Host-guest chemistry of Cu2+/Histidine complexes in molecular sieves

    NARCIS (Netherlands)

    Mesu, Jan Gijsbert

    2005-01-01

    The high activity and selectivity of enzymes have inspired many scientists to study the structure and working mechanism of bio-molecular complexes. Also in the catalysis community this subject is of topical interest, as it may provide inspiration for the development of a new generation of bio-inspir

  14. Coordination chemistry and reactivity of zinc complexes supported by a phosphido pincer ligand.

    Science.gov (United States)

    D'Auria, Ilaria; Lamberti, Marina; Mazzeo, Mina; Milione, Stefano; Roviello, Giuseppina; Pellecchia, Claudio

    2012-02-20

    The preparation and characterization of new Zn(II) complexes of the type [(PPP)ZnR] in which R = Et (1) or N(SiMe(3))(2) (2) and PPP is a tridentate monoanionic phosphido ligand (PPP-H = bis(2-diphenylphosphinophenyl)phosphine) are reported. Reaction of ZnEt(2) and Zn[N(SiMe(3))(2)](2) with one equivalent of proligand PPP-H produced the corresponding tetrahedral zinc ethyl (1) and zinc amido (2) complexes in high yield. Homoleptic (PPP)(2) Zn complex 3 was obtained by reaction of the precursors with two equivalents of the proligand. Structural characterization of 1-3 was achieved by multinuclear NMR spectroscopy ((1)H, (13)C, and (31)P) and X-ray crystallography (3). Variable-temperature (1)H and (31)P NMR studies highlighted marked flexibility of the phosphido pincer ligand in coordination at the metal center. A DFT calculation on the compounds provided theoretical support for this behavior. The activities of 1 and 2 toward the ring-opening polymerization of ε-caprolactone and of L- and rac-lactide were investigated, also in combination with an alcohol as external chain-transfer agent. Polyesters with controlled molecular parameters (M(n), end groups) and low polydispersities were obtained. A DFT study on ring-opening polymerization promoted by these complexes highlighted the importance of the coordinative flexibility of the ancillary ligand to promote monomer coordination at the reactive zinc center. Preliminary investigations showed the ability of these complexes to promote copolymerization of L-lactide and ε-caprolactone to achieve random copolymers whose microstructure reproduces the composition of the monomer feed.

  15. Experience in performing the commissioning procedures for meeting the requirements of water chemistry at NPP With VVER

    International Nuclear Information System (INIS)

    The integrity of NPP Unit equipment and pipelines is assured by strict following the requirements of rules and regulations by the NPP personnel in the field of nuclear power engineering and other regulatory documents. But all efforts of NPP personnel are unavailing in case of violation of the requirements of design documentation during Unit commissioning. Here the surface cleanness of equipment and pipelines during mounting, the post-mounting cleaning and assurance of water chemistry quality figures during commissioning procedures are of importance. During commissioning activities at the Unit of NPP with VVER a number of procedures are performed and the important place belongs to the procedures on water chemistry coordination. Post-mounting washing of steam generators is intended for cleaning and washing the steam generator internal surfaces against corrosion products, corrosive impurities, preservative residue and mounting fouling. During circulation washing of the reactor plant primary circuit the final cleaning of the internal surfaces is performed as well as preparing for formation of the protective oxide film. During reactor plant «hot» running-in the homogeneous solid protective oxide film is formed during a long-term interaction of the primary circuit internal surfaces with the alkaline reducing medium created due to proportioning of hydrazine and potassium hydroxide into the primary water. The composition and structure of the protective oxide film, formed on the internal surfaces, is such that its safe keeping is assured during Unit further operation. (author)

  16. Recent developments of surface complexation models applied to environmental aquatic chemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on numerous latest references, the current developments in surface complexation, surface precipitation and the corresponding models (SCMs and SPMs), were reviewed. The contents involved comparison on surface charge composition and layer-structure of solid-solution interface for the classical 1-pK and 2- pK models, In addition, the fundamental concept and relations of the new models, i.e., multi-site complexation (MUSIC) and charge -distribution (CD) MUSIC models were described as well. To avoid misuse or abuse, it must be emphasized that the applicability nd limitation for each model should be considered carefully when selecting the concerned model(s). In addition, some new powerful techniques for surface characterization and analysis applied to model establishment and modification were also briefly introduced.

  17. The complex chemistry of outflow cavity walls exposed: the case of low-mass protostars

    CERN Document Server

    Drozdovskaya, Maria N; Visser, Ruud; Harsono, Daniel; van Dishoeck, Ewine F

    2015-01-01

    Complex organic molecules are ubiquitous companions of young low-mass protostars. Recent observations suggest that their emission stems, not only from the traditional hot corino, but also from offset positions. In this work, 2D physicochemical modelling of an envelope-cavity system is carried out. Wavelength-dependent radiative transfer calculations are performed and a comprehensive gas-grain chemical network is used to simulate the physical and chemical structure. The morphology of the system delineates three distinct regions: the cavity wall layer with time-dependent and species-variant enhancements; a torus rich in complex organic ices, but not reflected in gas-phase abundances; and the remaining outer envelope abundant in simpler solid and gaseous molecules. Strongly irradiated regions, such as the cavity wall layer, are subject to frequent photodissociation in the solid phase. Subsequent recombination of the photoproducts leads to frequent reactive desorption, causing gas-phase enhancements of several or...

  18. A Neutrally Charged Trimethylmanganese(III) Complex: Synthesis, Characterization, and Disproportionation Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Stalzer, Madelyn M.; Telser, Joshua; Krzystek, Jurek; Motta, Alessandro; Delferro, Massimiliano; Marks, Tobin J.

    2016-08-22

    The synthesis and properties of an unusual, neutrally charged and volatile N,N,N',N'-tetramethylethylenediamine trimethyl manganese(III) complex, (TMEDA)MnMe3, are described, along with its facile disproportionation to the corresponding Mn(II) and Mn(IV) complexes. Characterization by single-crystal XRD, UV-vis spectroscopy, high-frequency and -field EPR (HFEPR), magnetic susceptibility, and density functional theory (DFT) computations indicate that the (TMEDA)MnMe3 electronic structure can be described as largely square pyramidal Mn(III) centered. The paucity of manganese(III) polyalkyls and the simplicity and reactivity of this compound implicate it as a potentially useful synthetic building block.

  19. Unified Microscopic-Macroscopic Monte Carlo Simulations of Complex Organic Molecule Chemistry in Cold Cores

    CERN Document Server

    Chang, Qiang

    2016-01-01

    The recent discovery of methyl formate and dimethyl ether in the gas phase of cold cores with temperatures as cold as 10 K challenges our previous astrochemical models concerning the formation of complex organic molecules. The strong correlation between the abundances and distributions of methyl formate and dimethyl ether further shows that current astrochemical models may be missing important chemical processes in cold astronomical sources. We investigate a scenario in which complex organic molecules and the methoxy radical can be formed on dust grains via a so-called "chain reaction" mechanism, in a similar manner to CO$_2$. A unified gas-grain microscopic-macroscopic Monte Carlo approach with both normal and interstitial sites for icy grain mantles is used to perform the chemical simulations. Reactive desorption with varying degrees of efficiency is included to enhance the non-thermal desorption of species formed on cold dust grains. In addition, varying degrees of efficiency for the surface formation of m...

  20. CONTRIBUTING TO THE DISCUSSIONS ON THE FUNDAMENTAL ASPECTS AND COMPLEXITIES OF TALSPEAK CHEMISTRY

    Energy Technology Data Exchange (ETDEWEB)

    Peter R. Zalupski; Leigh R. Martin

    2011-10-01

    When liquid-liquid distribution of lanthanides was monitored at Talspeak-related conditions a characteristic drop in the extraction efficiency was observed at high lactate concentrations. The lactate dependency trend also appears to be directly affected by the increasing complexity of the non-aqueous environment. Some considerations of the non-ideal solution behavior in aqueous and organic environment are presented here in an attempt to explain the observed metal partitioning trends. While the mechanism of metal ion phase transfer appears to adhere to the conventional thermodynamic struggle between HDEHP and DTPA, the diminished metal distribution and suppressed slopes for the extractant dependencies suggest further build-up in the complexity of the non-aqueous environment in Talspeak systems.

  1. The role of zinc on the chemistry of complex intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Weiwei [Iowa State Univ., Ames, IA (United States)

    2014-01-01

    Combining experiments and electronic structure theory provides the framework to design and discover new families of complex intermetallic phases and to understand factors that stabilize both new and known phases. Using solid state synthesis and multiple structural determinations, ferromagnetic β-Mn type Co8+xZn12–x was analyzed for their crystal and electronic structures.

  2. Chloromethane Complexation by Cryptophanes : Host-Guest Chemistry Investigated by NMR and Quantum Chemical Calculations

    OpenAIRE

    Takacs, Zoltan

    2012-01-01

    Host–guest complexes are widely investigated because of their importance in many industrial applications. The investigation of their physico–chemical properties helps understanding the inclusion phenomenon. The hosts investigated in this work are cryptophane molecules possessing a hydrophobic cavity. They can encapsulate small organic guests such as halo–methanes (CH2Cl2, CHCl3). The encapsulation process was investigated from both the guest and the host point of view. With the help of Nuclea...

  3. Macrocyclic and lantern complexes of palladium(II) with bis(amidopyridine) ligands: synthesis, structure, and host-guest chemistry.

    Science.gov (United States)

    Yue, Nancy L S; Eisler, Dana J; Jennings, Michael C; Puddephatt, Richard J

    2004-11-29

    The reactions of [PdCl2(NCPh)2] in a 1:1 ratio with the bis(amidopyridine) ligands LL=C6H3(5-R)(1,3-CONH-3-C5H4N)2 with R=H (1a) or R=t-Bu (1b) give the corresponding neutral dipalladium(II) macrocycles trans,trans-[Pd2Cl4(mu-LL)2], 2a and 2b, which crystallize from dimethylformamide with one or two solvent molecules as macrocycle guests. The reaction of [PdCl2(NCPh)2] with LL in a 1:2 ratio gave the cationic lantern complex [Pd2(mu-LL)4]Cl4, 3c (LL=1b), and the reaction in the presence of AgO2CCF3 gave the corresponding trifluoroacetate salts [Pd2(mu-LL)4](CF3CO2)4, 3a (LL=1a) and 3b (LL=1b). These lantern complexes exhibit a remarkable host-guest chemistry, as they can encapsulate cations, anions, and water molecules by interaction of the guest with either the electrophilic NH or the nucleophilic C=O substituents of the amide groups, which can be directed toward the center of the lantern through easy conformational change. The structures of several of these host-guest complexes were determined, and it was found that the cavity size and shape vary according to the ligand conformation, with Pd...Pd separations in the range from 9.45 to 11.95 A. Supramolecular ordering of the lanterns was observed in the solid state, through either hydrogen bonding or secondary bonding to the cationic palladium(II) centers. The selective inclusion by the lantern complexes of alkali metal ions in the sequence Na+ > K+ > Li+ was observed by ESI-MS.

  4. Synthesis, characterization, and reaction chemistry of a bis(iodosylbenzene)-metalloporphyrin complex, (PhI(OAc)O)/sub 2/Mn/sup IV/TPP. A complex possessing a five-electron oxidation capability

    Energy Technology Data Exchange (ETDEWEB)

    Smegal, J.A.; Hill, C.L.

    1983-05-04

    The synthesis, characterization, and reaction chemistry of a new type of manganese(IV) complex, (PhI(OAc)O)/sub 2/Mn/sup IV/TPP, which hydroxylates alkanes and epoxidizes olefins is reported. This complex contains both a transition metal (Mn) and a nonmetal ion (I) in unusual oxidation states. The high-valent iodine and manganese atoms provide this complex with a five-electron oxidation capability.

  5. An europium(III) diglycolamide complex: insights into the coordination chemistry of lanthanides in solvent extraction.

    Science.gov (United States)

    Antonio, Mark R; McAlister, Daniel R; Horwitz, E Philip

    2015-01-14

    The synthesis, stoichiometry, and structural characterization of a homoleptic, cationic europium(III) complex with three neutral tetraalkyldiglycolamide ligands are reported. The tri(bismuth tetrachloride)tris(N,N,N',N'-tetra-n-octyldiglycolamide)Eu salt, [Eu(TODGA)3][(BiCl4)3] obtained from methanol was examined by Eu L3-edge X-ray absorption spectroscopy (XAS) to reveal an inner-sphere coordination of Eu(3+) that arises from 9 O atoms and two next-nearest coordination spheres that arise from 6 carbon atoms each. A structural model is proposed in which each TODGA ligand with its O=Ca-Cb-O-Cb-Ca=O backbone acts as a tridentate O donor, where the two carbonyl O atoms and the one ether O atom bond to Eu(3+). Given the structural rigidity of the tridentate coordination motif in [Eu(TODGA)3](3+) with six 5-membered chelate rings, the six Eu-Ca and six Eu-Cb interactions are readily resolved in the EXAFS (extended X-ray absorption fine structure) spectrum. The three charge balancing [BiCl4](-) anions are beyond the cationic [Eu(TODGA)3](3+) cluster in an outer sphere environment that is too distant to be detected by XAS. Despite their sizeable length and propensity for entanglement, the four n-octyl groups of each TODGA (for a total of twelve) do not perturb the Eu(3+) coordination environment over that seen from previously reported single-crystal structures of tripositive lanthanide (Ln(3+)) complexes with tetraalkyldiglycolamide ligands (of the same 1:3 metal-to-ligand ratio stoichiometry) but having shorter i-propyl and i-butyl groups. The present results set the foundation for understanding advanced solvent extraction processes for the separation of the minor, tripositive actinides (Am, Cm) from the Ln(3+) ions in terms of the local structure of Eu(3+) in a solid state coordination complex with TODGA.

  6. Calcium sulfoaluminate cement blended with OPC: A potential binder to encapsulate low-level radioactive slurries of complex chemistry

    International Nuclear Information System (INIS)

    Investigations were carried out in order to solidify in cement a low-level radioactive waste of complex chemistry obtained by mixing two process streams, a slurry produced by ultra-filtration and an evaporator concentrate with a salinity of 600 gxL-1. Direct cementation with Portland cement (OPC) was not possible due to a very long setting time of cement resulting from borates and phosphates contained in the waste. According to a classical approach, this difficulty could be solved by pre-treating the waste to reduce adverse cement-waste interactions. A two-stage process was defined, including precipitation of phosphates and sulfates at 60 deg. C by adding calcium and barium hydroxide to the waste stream, and encapsulation with a blend of OPC and calcium aluminate cement (CAC) to convert borates into calcium quadriboroaluminate. The material obtained with a 30% waste loading complied with specifications. However, the pre-treatment step made the process complex and costly. A new alternative was then developed: the direct encapsulation of the waste with a blend of OPC and calcium sulfoaluminate cement (CSA) at room temperature. Setting inhibition was suppressed, which probably resulted from the fact that, when hydrating, CSA cement formed significant amounts of ettringite and calcium monosulfoaluminate hydrate which incorporated borates into their structure. As a consequence, the waste loading could be increased to 56% while keeping acceptable properties at the laboratory scale.

  7. Cyclic Tetranuclear and Hexanuclear Palladium(II) Complexes and Their Host-Guest Chemistry

    OpenAIRE

    Judith A. Walmsley; Zhu, Shourong; Matilla, Antonio; Donowick, Tiffanee G.; Cramp, Jessica E.; Tercero, Jose Manuel; Dalrymple, Tatyana

    2007-01-01

    Cyclic tetrameric complexes have been prepared by the reaction of Pd(en)Cl2 or Pd(dapol)Cl2, or their nitrato analogs, with Na2(5′GMP) in aqueous solution, where en = 1,2-diaminoethane, dapol = 1,3-diamino-2-propanol, 5′-GMP = guanosine 5′-monophosphate. Addition of certain small molecules containing hydrophobic groups resulted in the expansion of the tetramer to a cyclic hexamer with strong bonding of one guest per hexameric host. At pH 5-6, the guest molecule can be a cation, anion, or neut...

  8. 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...

  9. Supramolecular fullerene-porphyrin chemistry. Fullerene complexation by metalated "jaws porphyrin" hosts.

    Science.gov (United States)

    Sun, Dayong; Tham, Fook S; Reed, Christopher A; Chaker, Leila; Boyd, Peter D W

    2002-06-12

    Porphyrins and fullerenes are spontaneously attracted to each other. This new supramolecular recognition element is explored in discrete, soluble, coordinatively linked porphyrin and metalloporphyrin dimers. Jawlike clefts in these bis-porphyrins are effective hosts for fullerene guests. X-ray structures of the Cu complex with C60 and free-base complexes with C70 and a pyrrolidine-derivatized C60 have been obtained. The electron-rich 6:6 ring-juncture bonds of C60 show unusually close approach to the porphyrin or metalloporphyrin plane. Binding constants in toluene solution increase in the order Fe(II) metalated porphyrins. This is ascribed to electrostatic forces, enhancing the largely van der Waals forces of the pi-pi interaction. The ordering with metals is ascribed to a subtle interplay of solvation and weak interaction forces. Conflicting opinions on the relative importance of van der Waals forces, charge transfer, electrostatic attraction, and coordinate bonding are addressed. The supramolecular design principles arising from these studies have potential applications in the preparation of photophysical devices, molecular magnets, molecular conductors, and porous metal-organic frameworks. PMID:12047181

  10. Host-guest complexation of [60]fullerenes and porphyrins enabled by "click chemistry".

    Science.gov (United States)

    Ho, Khanh-Hy Le; Hijazi, Ismail; Rivier, Lucie; Gautier, Christelle; Jousselme, Bruno; de Miguel, Gustavo; Romero-Nieto, Carlos; Guldi, Dirk M; Heinrich, Benoit; Donnio, Bertrand; Campidelli, Stéphane

    2013-08-19

    Herein the synthesis, characterization, and organization of a first-generation dendritic fulleropyrrolidine bearing two pending porphyrins are reported. Both the dendron and the fullerene derivatives were synthesized by Cu(I) -catalyzed alkyne-azide cycloaddition (CuAAC). The electron-donor-acceptor conjugate possesses a shape that allows the formation of supramolecular complexes by encapsulation of C60 within the jaws of the two porphyrins of another molecule. The interactions between the two photoactive units (i.e., C60 and Zn-porphyrin) were confirmed by cyclic voltammetry as well as by steady-state and time-resolved spectroscopy. For example, a shift of about 85 mV was found for the first reduction of C60 in the electron-donor-acceptor conjugate compared with the parent molecules, which indicates that C60 is included in the jaws of the porphyrin. The fulleropyrrolidine compound exhibits a rich polymorphism, which was corroborated by AFM and SEM. In particular, it was found to form supramolecular fibrils when deposited on substrates. The morphology of the fibrils suggests that they are formed by several rows of fullerene-porphyrin complexes.

  11. Proceedings of the meeting on computational and experimental studies for modeling of radionuclide migration in complex aquatic ecosystems

    International Nuclear Information System (INIS)

    The Research Group for Environmental Science of JAEA held a meeting on computational and experimental studies for modeling of radionuclide migration in complex aquatic ecosystems during November 16-20 of 2009. The aim was to discuss the relevance of various computational and experimental approaches to that modeling. The meeting was attended by a Swedish researcher, Prof. Dr. Lars Hakanson of Uppsala University. It included a joint talk at the Institute for Environmental Sciences, in addition to a field and facility survey of the JNFL commercial reprocessing plant located in Rokkasho, Aomori. The meeting demonstrated that it is crucial 1) to make a model structure be strictly relevant to the target objectives of a study and 2) to account for inherent fluctuations in target values in nature in a manner of qualitative parameterization. Moreover, it was confirmed that there can be multiple different approaches of modeling (e.g. detailed or simplified) with relevance for the objectives of a study. These discussions should be considered in model integration for complex aquatic ecosystems consisting catchments, rivers, lakes and coastal oceans which can interact with the atmosphere. This report compiles research subjects and lectures presented at the meeting with associated discussions. The 10 of the presented papers indexed individually. (J.P.N.)

  12. Microscale Synthesis, Reactions, and (Super 1)H NMR Spectroscopic Investigations of Square Planar Macrocyclic, Tetramido-N Co(III) Complexes Relevant to Green Chemistry

    Science.gov (United States)

    Watson, Tanya T.; Uffelman, Erich S.; Lee, Daniel W., III; Doherty, Jonathan R.; Schulze, Carl; Burke, Amy L.; Bonnema, Kristen, R.

    2004-01-01

    The microscale preparation, characterization, and reactivity of a square planar Co(III) complex that has grown out of a program to introduce experiments of relevance to green chemistry into the undergraduate curriculum is presented. The given experiments illustrate the remarkable redox and aqueous acid-base stability that make the macrocycles very…

  13. Microscale Syntheses, Reactions, and 1H NMR Spectroscopic Investigations of Square Planar Macrocyclic Tetraamido-N Cu(III) Complexes Relevant to Green Chemistry

    Science.gov (United States)

    Uffelman, Erich S.; Doherty, Jonathan R.; Schulze, Carl; Burke, Amy L.; Bonnema, Kristen R.; Watson, Tanya T.; Lee, Daniel W., III

    2004-01-01

    Microscale fusions, description, and spectroscopic analysis of the reactivity of a square planar Cu(III) complex significant to green chemistry, are presented. The experiment also includes nine focal points on which pre-lab and post-lab questions are based, and the final exams reflect the students' comprehension of these and other features of…

  14. Cationic terminal gallylene complexes by halide abstraction: coordination chemistry of a valence isoelectronic analogue of CO and N2.

    Science.gov (United States)

    Coombs, Natalie D; Vidovic, Dragoslav; Day, Joanna K; Thompson, Amber L; Le Pevelen, Delphine D; Stasch, Andreas; Clegg, William; Russo, Luca; Male, Louise; Hursthouse, Michael B; Willock, David J; Aldridge, Simon

    2008-11-26

    While N(2) and CO have played central roles in developing models of electronic structure, and their interactions with transition metals have been widely investigated, the valence isoelectronic diatomic molecules EX (E = group 13 element, X = group 17 element) have yet to be isolated under ambient conditions, either as the "free" molecule or as a ligand in a simple metal complex. As part of a program designed to address this deficiency, together with wider issues of the chemistry of cationic systems [L(n)M(ER)](+) (E = B, Al, Ga; R = aryl, amido, halide), we have targeted complexes of the type [L(n)M(GaX)](+). Halide abstraction is shown to be a viable method for the generation of mononuclear cationic complexes containing gallium donor ligands. The ability to isolate tractable two-coordinate products, however, is strongly dependent on the steric and electronic properties of the metal/ligand fragment. In the case of complexes containing ancillary pi-acceptor ligands such as CO, cationic complexes can only be isolated as base-trapped adducts, even with bulky aryl substituents at gallium. Base-free gallylene species such as [Cp*Fe(CO)(2)(GaMes)](+) can be identified only in the vapor phase by electrospray mass spectrometry experiments. With bis(phosphine) donor sets at the metal, the more favorable steric/electronic environment allows for the isolation of two-coordinate ligand systems, even with halide substituents at gallium. Thus, [Cp*Fe(dppe)(GaI)](+)[BAr(f)(4)](-) (9) can be synthesized and shown crystallographically to feature a terminally bound GaI ligand; 9 represents the first experimental realization of a complex containing a valence isoelectronic group 13/group 17 analogue of CO and N(2). DFT calculations reveal a relatively weakly bound GaI ligand, which is confirmed experimentally by the reaction of 9 with CO to give [Cp*Fe(dppe)(CO)](+)[BAr(f)(4)](-). In the absence of such reagents, 9 is stable for weeks in fluorobenzene solution, presumably reflecting (i

  15. ADAPTATION OF N-HEPTANE AUTOIGNITION TABULATION FOR COMPLEX CHEMISTRY MECHANISMS

    Directory of Open Access Journals (Sweden)

    Neven Duić

    2011-01-01

    Full Text Available The adaptation of auto-ignition tabulation for effective use of complex chemical mechanisms will be presented in this paper. Taking cool flame ignition phenomenon into account could improve numerical simulations of combustion in compression ignition engines. Current approaches of successful simulation of this phenomenon are based on the extraction of ignition delay times, heat releases and also reaction rates from tabulated data dependant on four parameters: temperature, pressure, equivalence ratio and exhaust gasses mass fraction. The methods described here were used to create lookup tables including cool flame using a comprehensive chemical mechanism without including reaction rates data (as used by other authors. The method proved to be stable for creating tables and these results will be shown, as well as initial implementation results using the tables in computational fluid dynamics software.

  16. Payette River Basin Project: Improving Operational Forecasting in Complex Terrain through Chemistry

    Science.gov (United States)

    Blestrud, D.; Kunkel, M. L.; Parkinson, S.; Holbrook, V. P.; Benner, S. G.; Fisher, J.

    2015-12-01

    Idaho Power Company (IPC) is an investor owned hydroelectric based utility, serving customers throughout southern Idaho and eastern Oregon. The University of Arizona (UA) runs an operational 1.8-km resolution Weather and Research Forecast (WRF) model for IPC, which is incorporated into IPC near and real-time forecasts for hydro, solar and wind generation, load servicing and a large-scale wintertime cloud seeding operation to increase winter snowpack. Winter snowpack is critical to IPC, as hydropower provides ~50% of the company's generation needs. In efforts to improve IPC's near-term forecasts and operational guidance to its cloud seeding program, IPC is working extensively with UA and the National Center for Atmospheric Research (NCAR) to improve WRF performance in the complex terrain of central Idaho. As part of this project, NCAR has developed a WRF based cloud seeding module (WRF CS) to deliver high-resolution, tailored forecasts to provide accurate guidance for IPC's operations. Working with Boise State University (BSU), IPC is conducting a multiyear campaign to validate the WRF CS's ability to account for and disperse the cloud seeding agent (AgI) within the boundary layer. This improved understanding of how WRF handles the AgI dispersion and fate will improve the understanding and ultimately the performance of WRF to forecast other parameters. As part of this campaign, IPC has developed an extensive ground based monitoring network including a Remote Area Snow Sampling Device (RASSD) that provides spatially and temporally discrete snow samples during active cloud seeding periods. To quantify AgI dispersion in the complex terrain, BSU conducts trace element analysis using LA-ICP-MS on the RASSD sampled snow to provide measurements (at the 10-12 level) of incorporated AgI, measurements are compare directly with WRF CS's estimates of distributed AgI. Modeling and analysis results from previous year's research and plans for coming seasons will be presented.

  17. Gas Phase Chemistry and Molecular Complexity: How Far Do They Go?

    Science.gov (United States)

    Balucani, Nadia

    2016-07-01

    The accumulation of organic molecules of increasing complexity is believed to be an important step toward the emergence of life. But how massive organic synthesis could occur in primitive Earth, i.e. a water-dominated environment, is a matter of debate. Two alternative theories have been suggested so far: endogenous and exogenous synthesis. In the first theory, the synthesis of simple organic molecules having a strong prebiotic potential (simple prebiotic molecules SPMs, such as H2CO, HCN, HC3N, NH2CHO) occurred directly on our planet starting from simple parent molecules of the atmosphere, liquid water and various energy sources. Miller's experiment was a milestone in this theory, but it was later recognized that the complexity of a planet cannot be reproduced in a single laboratory experiment. Some SPMs have been identified in the N2-dominated atmosphere of Titan (a massive moon of Saturn), which is believed to be reminiscent of the primitive terrestrial atmosphere. As such, the atmosphere of Titan represents a planetary scale laboratory for the comprehension of SPM formation in an environment close enough to primitive Earth and is the current frontier in the endogenous theory exploration. In the exogenous theory, SPMs came from space, the carriers being comets, asteroids and meteorites. The rationale behind this suggestion is that plenty of SPMs have been observed in interstellar clouds (ISCs), including star-forming regions, and in small bodies like comets, asteroids and meteorites. Therefore, the basic idea is that SPMs were formed in the solar nebula, preserved during the early phases of the Solar System formation in the body of comets/asteroids/meteorites and finally delivered to Earth by cometary and meteoritic falls. In this contribution, the status of our knowledge on how SPMs can be formed in the gas phase, either in the primitive terrestrial atmosphere or in the cold nebula from which the Solar System originated, will be presented. Particular attention

  18. Water oxidation chemistry of a synthetic dinuclear ruthenium complex containing redox-active quinone ligands.

    Science.gov (United States)

    Isobe, Hiroshi; Tanaka, Koji; Shen, Jian-Ren; Yamaguchi, Kizashi

    2014-04-21

    We investigated theoretically the catalytic mechanism of electrochemical water oxidation in aqueous solution by a dinuclear ruthenium complex containing redox-active quinone ligands, [Ru2(X)(Y)(3,6-tBu2Q)2(btpyan)](m+) [X, Y = H2O, OH, O, O2; 3,6-tBu2Q = 3,6-di-tert-butyl-1,2-benzoquinone; btpyan =1,8-bis(2,2':6',2″-terpyrid-4'-yl)anthracene] (m = 2, 3, 4) (1). The reaction involves a series of electron and proton transfers to achieve redox leveling, with intervening chemical transformations in a mesh scheme, and the entire molecular structure and motion of the catalyst 1 work together to drive the catalytic cycle for water oxidation. Two substrate water molecules can bind to 1 with simultaneous loss of one or two proton(s), which allows pH-dependent variability in the proportion of substrate-bound structures and following pathways for oxidative activation of the aqua/hydroxo ligands at low thermodynamic and kinetic costs. The resulting bis-oxo intermediates then undergo endothermic O-O radical coupling between two Ru(III)-O(•) units in an anti-coplanar conformation leading to bridged μ-peroxo or μ-superoxo intermediates. The μ-superoxo species can liberate oxygen with the necessity for the preceding binding of a water molecule, which is possible only after four-electron oxidation is completed. The magnitude of catalytic current would be limited by the inherent sluggishness of the hinge-like bending motion of the bridged μ-superoxo complex that opens up the compact, hydrophobic active site of the catalyst and thereby allows water entry under dynamic conditions. On the basis of a newly proposed mechanism, we rationalize the experimentally observed behavior of electrode kinetics with respect to potential and discuss what causes a high overpotential for water oxidation by 1.

  19. 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...

  20. Complex Coupling of Air Quality and Climate-Relevant Aerosols in a Chemistry-Aerosol Microphysics Model

    Science.gov (United States)

    Yoshioka, M.; Carslaw, K. S.; Reddington, C.; Mann, G.

    2013-12-01

    Controlling emissions of aerosols and their precursors to improve air quality will impact the climate through direct and indirect radiative forcing. We have investigated the impacts of changes in a range of aerosol and gas-phase emission fluxes and changes in temperature on air quality and climate change metrics using a global aerosol microphysics and chemistry model, GLOMAP. We investigate how the responses of PM2.5 and cloud condensation nuclei (CCN) are coupled, and how attempts to improve air quality could have inadvertent effects on CCN, clouds and climate. The parameter perturbations considered are a 5°C increase in global temperature, increased or decreased precursor emissions of anthropogenic SO2, NH3, and NOx, and biogenic monoterpenes, and increased or decreased primary emissions of organic and black carbon aerosols from wildfire, fossil fuel, and biofuel. To quantify the interactions, we define a new sensitivity metric in terms of the response of CCN divided by the response of PM in different regions. .Our results show that the coupled chemistry and aerosol processes cause complex responses that will make any co-benefit policy decision problematic. In particular, we show that reducing SO2 emissions effectively reduces surface-level PM2.5 over continental regions in summer when background PM2.5 is high, with a relatively small reduction in marine CCN (and hence indirect radiative cooling over ocean), which is beneficial for near-term climate. Reducing NOx emissions does not improve summertime air quality very effectively but leads to a relatively high reduction of marine CCN. Reducing NH3 emissions has moderate effects on both PM2.5 and CCN. These three species are strongly coupled chemically and microphysically and the effects of changing emissions of one species on mass and size distributions of aerosols are very complex and spatially and temporally variable. For example, reducing SO2 emissions leads to reductions in sulphate and ammonium mass

  1. Unified Microscopic-Macroscopic Monte Carlo Simulations of Complex Organic Molecule Chemistry in Cold Cores

    Science.gov (United States)

    Chang, Qiang; Herbst, Eric

    2016-03-01

    The recent discovery of methyl formate and dimethyl ether in the gas phase of cold cores with temperatures as cold as 10 K challenges our previous astrochemical models concerning the formation of complex organic molecules (COMs). The strong correlation between the abundances and distributions of methyl formate and dimethyl ether further shows that current astrochemical models may be missing important chemical processes in cold astronomical sources. We investigate a scenario in which COMs and the methoxy radical can be formed on dust grains via a so-called chain reaction mechanism, in a similar manner to CO2. A unified gas-grain microscopic-macroscopic Monte Carlo approach with both normal and interstitial sites for icy grain mantles is used to perform the chemical simulations. Reactive desorption with varying degrees of efficiency is included to enhance the nonthermal desorption of species formed on cold dust grains. In addition, varying degrees of efficiency for the surface formation of methoxy are also included. The observed abundances of a variety of organic molecules in cold cores can be reproduced in our models. The strong correlation between the abundances of methyl formate and dimethyl ether in cold cores can also be explained. Nondiffusive chemical reactions on dust grain surfaces may play a key role in the formation of some COMs.

  2. Tetrapositive plutonium, neptunium, uranium, and thorium coordination complexes: chemistry revealed by electron transfer and collision induced dissociation.

    Science.gov (United States)

    Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K

    2014-04-17

    The Pu(4+), Np(4+), and U(4+) ions, which have large electron affinities of ∼34.6, ∼33.6, and ∼32.6 eV, respectively, were stabilized from solution to the gas phase upon coordination by three neutral tetramethyl-3-oxa-glutaramide ligands (TMOGA). Both collision induced dissociation (CID) and electron transfer dissociation (ETD) of Pu(TMOGA)3(4+) reveal the propensity for reduction of Pu(IV) to Pu(III), by loss of TMOGA(+) in CID and by simple electron transfer in ETD. The reduction of Pu(IV) is in distinct contrast to retention of Th(IV) in both CID and ETD of Th(TMOGA)3(4+), where only the C-Oether bond cleavage product was observed. U(TMOGA)3(4+) behaves similarly to Th(TMOGA)3(4+) upon CID and ETD, while the fragmentation patterns of Np(TMOGA)3(4+) lie between those of Pu(TMOGA)3(4+) and U(TMOGA)3(4+). It is notable that the gas-phase fragmentation behaviors of these exceptional tetrapositive complexes parallel fundamental differences in condensed phase chemistry within the actinide series, specifically the tendency for reduction from the IV to III oxidation states.

  3. Tetrapositive plutonium, neptunium, uranium, and thorium coordination complexes: chemistry revealed by electron transfer and collision induced dissociation.

    Science.gov (United States)

    Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K

    2014-04-17

    The Pu(4+), Np(4+), and U(4+) ions, which have large electron affinities of ∼34.6, ∼33.6, and ∼32.6 eV, respectively, were stabilized from solution to the gas phase upon coordination by three neutral tetramethyl-3-oxa-glutaramide ligands (TMOGA). Both collision induced dissociation (CID) and electron transfer dissociation (ETD) of Pu(TMOGA)3(4+) reveal the propensity for reduction of Pu(IV) to Pu(III), by loss of TMOGA(+) in CID and by simple electron transfer in ETD. The reduction of Pu(IV) is in distinct contrast to retention of Th(IV) in both CID and ETD of Th(TMOGA)3(4+), where only the C-Oether bond cleavage product was observed. U(TMOGA)3(4+) behaves similarly to Th(TMOGA)3(4+) upon CID and ETD, while the fragmentation patterns of Np(TMOGA)3(4+) lie between those of Pu(TMOGA)3(4+) and U(TMOGA)3(4+). It is notable that the gas-phase fragmentation behaviors of these exceptional tetrapositive complexes parallel fundamental differences in condensed phase chemistry within the actinide series, specifically the tendency for reduction from the IV to III oxidation states. PMID:24660979

  4. A quantum chemistry study of actinide(III) and lanthanide(III) complexes with tridentate nitrogen ligands

    Energy Technology Data Exchange (ETDEWEB)

    Guillaumont, D

    2004-07-01

    The structure and bonding in large complexes of actinide(III) and lanthanide(III) with tridentate N-donor ligands and water molecules have been investigated through quantum chemistry calculations in order to characterize the nature of the lanthanide-ligand and actinide-ligand bonds. Calculations have been performed using relativistic density functional theory on [M(L)(H{sub 2}O){sub 6}]{sup 3+}, [M(L)(H{sub 2}O){sub 5}Cl]{sup 2+} and [M(H{sub 2}O){sub 9}]{sup 3+} clusters where M = La, Ce, Nd, U, Pu, Am or Cm and L = 2,2':6'2''ter-pyridine (Terpy) or 2,6-bis(5,6-di-methyl-1,2,4-triazine-3-yl)pyridine (MeBtp). The calculated evolution of the M-L bond as a function of the cation shows that lanthanide-ligand distances decrease with the diminution of the ionic radius, whereas the actinide-ligand distances increase from uranium to americium and are shorter than Ln-N distances. These trends are explained by the presence of covalent effects in the metal-ligand decreasing in the order U > Pu > Am {approx_equal} Cm {approx_equal} Ln. (author)

  5. Stratigraphy, petrology, and geochemistry of the Spurr Volcanic Complex, eastern Aleutian Arc, Alaska. [(Appendix for geothermal fluid chemistry)

    Energy Technology Data Exchange (ETDEWEB)

    Nye, C.J.

    1987-12-01

    The Spurr Volcanic Complex (SVC) is a calcalkaline, medium-K, sequence of andesites erupted over the last quarter of a million years by the easternmost currently active volcanic center in the Aleutian Arc. The ancestral Mt. Spurr was built mostly of andesites of uniform composition (58 to 60% SiO/sub 2/), although andesite production was episodically interrupted by the introduction of new batches of more mafic magma. Near the end of the Pleistocene the ancestral Mt. Spurr underwent Bezyianny-type avalanche caldera formation, resulting in the production of a volcanic debris avalanche with overlying ashflows. Immediately afterward, a large dome (the present Mt. Spurr) was emplaced in the caldera. Both the ashflows and dome are made of acid andesite more silicic than any analyzed lavas from the ancestral Mt. Spurr (60 to 63% SiO/sub 2/), yet contain olivine and amphibole xenocrysts derived from more mafic magma. The mafic magma (53 to 57% SiO/sub 2/) erupted during and after dome emplacement, forming proto-Crater Peak and Crater Peak. Hybrid pyroclastic flows and lavas were also produced. Proto-Crater Peak underwent glacial dissection prior to the formation of Crater Peak in approximately the same location. Appendices II through VIII contain a summary of mineral compositions; Appendix I contains geochemical data. Appendix IX by R.J. Motyka and C.J. Nye describes the chemistry of geothermal fluids. 78 refs., 16 figs., 3 tabs.

  6. On being green: can flow chemistry help?

    Science.gov (United States)

    Ley, Steven V

    2012-08-01

    The principles of Green Chemistry are important but challenging drivers for most modern synthesis programs. To meet these challenges new flow chemistry tools are proving to be very effective by providing improved heat/mass transfer opportunities, lower solvent usage, less waste generation, hazardous compound containment, and the possibility of a 24/7 working regime. This machine-assisted approach can be used to effect repetitive or routine scale-up steps or when combined with reagent and scavenger cartridges, to achieve multi-step synthesis of complex natural products and pharmaceutical agents. PMID:22711555

  7. Yearly scientific meeting: chemistry in human health and environment protection. Bialystok`92; Doroczny zjazd naukowy: chemia w ochronie zdrowia i srodowiska czlowieka. Bialystok`92

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-12-31

    The conference has been divided into 12 sections devoted to following topics: analytical chemistry; environmental chemistry; chemistry of natural compounds; chemistry of pharmaceutics and toxic compounds; chemistry in medicine; electrochemistry; young scientists forum; didactics and history of chemistry; chemistry and industry - technologies environment friendly; new trends in polymer science; crystallochemistry; pro-ecological actions in leather industry. Different analytical methods for determination of heavy methods and rare earths have been presented. Some of them have been successfully applied for the examination of environmental and biological materials. The basic chemical and physico-chemical studies including thermodynamic, crystal structure, coordination chemistry, sorption properties etc. have been extensively resented. The existence of radioactive elements in environment has been also investigated, especially in respect to municipal and industrial wastes and products of their processing. The radiation effects for different materials have been reported and discussed as well.

  8. Synthesis of the Multinuclear Cobaloxime Complexes via Click Chemistry as Catalysts for the Formation of Cyclic Carbonates from Carbon Dioxide and Epoxides

    Indian Academy of Sciences (India)

    Ahmet Kilic; Armagan Keles; Emine Aytar; Mustafa Durgun; Mahmut Ulusoy

    2015-09-01

    In this study, the structurally similar multinuclear cobaloxime complexes based on dioxime ligands were synthesized and characterized as trinuclear complexes with respect to varied axial groups. The multinuclear cobaloxime complexes were characterized by 1H, 13C-NMR, FT-IR, UV-Vis, LC-MS spectra, melting point and magnetic susceptibility measurements. These multinuclear cobaloxime complexes have been successfully applied to the synthesis of cyclic carbonates from CO2 and epoxides under optimized conditions and with-out using any solvent. All multinuclear cobaloxime complexes obtained by click chemistry are good catalysts for the cycloaddition of CO2 to different epoxides in the presence of pyridine as a co-catalyst. Additionally, the effects of epoxides, bases, temperature, pressure, and time on the yield of cyclic carbonates were investigated.

  9. Coordination Chemistry of Polyaromatic Thiosemicarbazones 2: Synthesis and Biological Activity of Zinc, Cobalt, and Copper Complexes of 1-(Naphthalene-2-yl)ethanone Thiosemicarbazone

    OpenAIRE

    Marc-Andre LeBlanc; Antonio Gonzalez-Sarrías; Beckford, Floyd A.; P. Canisius Mbarushimana; Seeram, Navindra P.

    2011-01-01

    A novel thiosemicarbazone from 2-acetonaphthone (represented as acnTSC) has been synthesized and its basic coordination chemistry with zinc(II), cobalt(II), and copper(II) explored. The complexes were characterized by elemental analysis and various spectroscopic techniques and are best formulated as [M(acnTSC)2Cl2] with the metal likely in an octahedral environment. The anticancer activity of the complexes was determined against a panel of human colon cancer cells (HCT-116 and Caco-2). The co...

  10. 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

  11. 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...

  12. Extending molecular simulation time scales: Parallel in time integrations for high-level quantum chemistry and complex force representations

    Science.gov (United States)

    Bylaska, Eric J.; Weare, Jonathan Q.; Weare, John H.

    2013-08-01

    Parallel in time simulation algorithms are presented and applied to conventional molecular dynamics (MD) and ab initio molecular dynamics (AIMD) models of realistic complexity. Assuming that a forward time integrator, f (e.g., Verlet algorithm), is available to propagate the system from time ti (trajectory positions and velocities xi = (ri, vi)) to time ti + 1 (xi + 1) by xi + 1 = fi(xi), the dynamics problem spanning an interval from t0…tM can be transformed into a root finding problem, F(X) = [xi - f(x(i - 1)]i = 1, M = 0, for the trajectory variables. The root finding problem is solved using a variety of root finding techniques, including quasi-Newton and preconditioned quasi-Newton schemes that are all unconditionally convergent. The algorithms are parallelized by assigning a processor to each time-step entry in the columns of F(X). The relation of this approach to other recently proposed parallel in time methods is discussed, and the effectiveness of various approaches to solving the root finding problem is tested. We demonstrate that more efficient dynamical models based on simplified interactions or coarsening time-steps provide preconditioners for the root finding problem. However, for MD and AIMD simulations, such preconditioners are not required to obtain reasonable convergence and their cost must be considered in the performance of the algorithm. The parallel in time algorithms developed are tested by applying them to MD and AIMD simulations of size and complexity similar to those encountered in present day applications. These include a 1000 Si atom MD simulation using Stillinger-Weber potentials, and a HCl + 4H2O AIMD simulation at the MP2 level. The maximum speedup (serial execution time/parallel execution time) obtained by parallelizing the Stillinger-Weber MD simulation was nearly 3.0. For the AIMD MP2 simulations, the algorithms achieved speedups of up to 14.3. The parallel in time algorithms can be implemented in a distributed computing

  13. Extending molecular simulation time scales: Parallel in time integrations for high-level quantum chemistry and complex force representations

    International Nuclear Information System (INIS)

    Parallel in time simulation algorithms are presented and applied to conventional molecular dynamics (MD) and ab initio molecular dynamics (AIMD) models of realistic complexity. Assuming that a forward time integrator, f (e.g., Verlet algorithm), is available to propagate the system from time ti (trajectory positions and velocities xi = (ri, vi)) to time ti+1 (xi+1) by xi+1 = fi(xi), the dynamics problem spanning an interval from t0…tM can be transformed into a root finding problem, F(X) = [xi − f(x(i−1)]i=1,M = 0, for the trajectory variables. The root finding problem is solved using a variety of root finding techniques, including quasi-Newton and preconditioned quasi-Newton schemes that are all unconditionally convergent. The algorithms are parallelized by assigning a processor to each time-step entry in the columns of F(X). The relation of this approach to other recently proposed parallel in time methods is discussed, and the effectiveness of various approaches to solving the root finding problem is tested. We demonstrate that more efficient dynamical models based on simplified interactions or coarsening time-steps provide preconditioners for the root finding problem. However, for MD and AIMD simulations, such preconditioners are not required to obtain reasonable convergence and their cost must be considered in the performance of the algorithm. The parallel in time algorithms developed are tested by applying them to MD and AIMD simulations of size and complexity similar to those encountered in present day applications. These include a 1000 Si atom MD simulation using Stillinger-Weber potentials, and a HCl + 4H2O AIMD simulation at the MP2 level. The maximum speedup ((serial execution time)/(parallel execution time) ) obtained by parallelizing the Stillinger-Weber MD simulation was nearly 3.0. For the AIMD MP2 simulations, the algorithms achieved speedups of up to 14.3. The parallel in time algorithms can be implemented in a distributed computing environment

  14. Preparation and Reactions of the 1,1-Dithiolato Complexes of Ni(II). An Undergraduate Coordination Chemistry Experiment.

    Science.gov (United States)

    Ballester, L.; Perpinan, M. F.

    1988-01-01

    Described is an undergraduate coordination chemistry experiment that enables students to relate concepts developed in class about the stereochemistry and coordination numbers to the interpretation of the electronic and infrared spectra and their magnetic behavior. Indicates that thermal decomposition and x-ray diffraction studies can also be…

  15. Coordination Chemistry of Polyaromatic Thiosemicarbazones 2: Synthesis and Biological Activity of Zinc, Cobalt, and Copper Complexes of 1-(Naphthalene-2-yl)ethanone Thiosemicarbazone

    Science.gov (United States)

    LeBlanc, Marc-Andre; Gonzalez-Sarrías, Antonio; Beckford, Floyd A.; Mbarushimana, P. Canisius; Seeram, Navindra P.

    2012-01-01

    A novel thiosemicarbazone from 2-acetonaphthone (represented as acnTSC) has been synthesized and its basic coordination chemistry with zinc(II), cobalt(II), and copper(II) explored. The complexes were characterized by elemental analysis and various spectroscopic techniques and are best formulated as [M(acnTSC)2Cl2] with the metal likely in an octahedral environment. The anticancer activity of the complexes was determined against a panel of human colon cancer cells (HCT-116 and Caco-2). The compounds bind to DNA via an intercalative mode with binding constants of 9.7 × 104 M−1, 1.8 × 105 M−1, and 9.5 × 104 M−1 for the zinc, cobalt, and copper complexes, respectively. PMID:22303515

  16. A new PC(sp(3))P ligand and its coordination chemistry with low-valent iron, cobalt and nickel complexes.

    Science.gov (United States)

    Zhu, Gengyu; Li, Xiaoyan; Xu, Guoqiang; Wang, Lin; Sun, Hongjian

    2014-06-21

    A new PC(sp(3))P ligand N,N'-bis(diphenylphosphino)dipyrromethane [PCH2P] (1) was prepared and its iron, cobalt and nickel chemistry was explored. Two pincer-type complexes [PCHP]Fe(H)(PMe3)2 (2) and [PCHP]Co(PMe3)2 (4) were synthesized in the reaction of with Fe(PMe3)4 and Co(Me)(PMe3)4. 1 reacted with Co(PMe3)4 and Ni(PMe3)4 to afford Co(0) and Ni(0) complexes [PCH2P]Co(PMe3)2 (3) and [PCH2P]Ni(PMe3)2 (5). The structures of complexes 2-5 were determined by X-ray diffraction.

  17. Coordination Chemistry of Polyaromatic Thiosemicarbazones 2: Synthesis and Biological Activity of Zinc, Cobalt, and Copper Complexes of 1-(Naphthalene-2-ylethanone Thiosemicarbazone

    Directory of Open Access Journals (Sweden)

    Marc-Andre LeBlanc

    2011-01-01

    Full Text Available A novel thiosemicarbazone from 2-acetonaphthone (represented as acnTSC has been synthesized and its basic coordination chemistry with zinc(II, cobalt(II, and copper(II explored. The complexes were characterized by elemental analysis and various spectroscopic techniques and are best formulated as [M(acnTSC2Cl2] with the metal likely in an octahedral environment. The anticancer activity of the complexes was determined against a panel of human colon cancer cells (HCT-116 and Caco-2. The compounds bind to DNA via an intercalative mode with binding constants of 9.7×104 M-1, 1.8×105 M-1, and 9.5×104 M-1 for the zinc, cobalt, and copper complexes, respectively.

  18. Synthesis, chemistry, and catalytic activity of complexes of lanthanide and actinide metals in unusual oxidation states and coordination environments. Progress report, February 1, 1981-January 31, 1982

    International Nuclear Information System (INIS)

    The objectives of this research project are: (1) to demonstrate experimentally that the lanthanide and actinide metals have a more extensive chemistry than is presently known; (2) to develop a better understanding of the special features of the f orbital elements which will allow the design of f orbital complexes possessing unique chemical and physical properties; (3) to provide a basis for seeking unusual catalytic transformations involving these elements; and (4) to synthesize and explore the chemical and physical properties of mixed metal complexes which contain both lanthanide and transition metals. During the past year progress was made in each area. Some of the specific results are: (1) the first activation of CO by an organolanthanide complex was demonstrated; (2) the first, crystallograhically characterized, molecular lanthanide hydride complexes, the bridged dimers, [(C5H4R)2LnH(THF)]2 (R=H, CH3; Ln=Lu, Er, Y), were synthesized by hydrogenolysis of the appropriate (C5H4R)2Ln(C(CH3)3)(THF) complex; (3) [(C5H5)2(THF)ErH]2 was found to catalyze the homogeneous hydrogenation of alkynes; (4) the first trimetallic organolanthanide complex was synthesized; (5) the first polyhydridic organolanthanide complex was synthesized; (6) U(III) hydride was found to catalytically activate molecular hydrogen in alkene and alkyne hydrogenation reactions

  19. Complexity Meets Development - A Felicitous Encounter on the Road of Life

    Directory of Open Access Journals (Sweden)

    Lewis L. Smith

    2007-10-01

    Full Text Available Since before Adam Smith, economists have been concerned with development. However, they have seldom understood it or paid it enough mind. For example, the “sequence” economists, such as Marx in the 19th Century and Rostow in the 20th sought to force development everywhere into a rigid pattern. Since 1874, the marginalists and their Neoliberal descendents have emphasised comparative statics and steady-state equilibriums, not growth.Although many new ideas popped up after WW II, none proved satisfactory. These included alleged “silver bullets” such as “free” trade, foreign direct investment, import substitution, industrialization and investment in human capital, as well as varied sets of “multiple drivers”, whose individual effects proved hard to sort out.Meanwhile, Neoliberal economics gradually took over the non-Marxist world. But it lost its credibility by spawning a mindless globalisation and long series of economic, human and social disasters. So today development economics is undergoing a “rebirth”, with “the Barcelona Consensus”, custom design, multiple objectives and sustainability among its guiding stars.By happy coincidence, a new discipline called complexity began to emerge in the mid 1980’s. Out of it has come a new kind of economics which is not only congruent with current thinking about development but also provides useful advice in the design and management of development programs, including those related to poverty.Meanwhile the Commonwealth of Puerto Rico (USA is trying a new approach to the eradication of this evil. Poor communities have been identified, organised and then made responsible for taking the lead in coordinating their own development. This coordination covers not only projects managed by the community but those sponsored by outside private- and public-sector organisations. The “jury is still out” but the odds are that this approach will provide much more civic, economic and social

  20. Human Development VIII: A Theory of “Deep” Quantum Chemistry and Cell Consciousness: Quantum Chemistry Controls Genes and Biochemistry to Give Cells and Higher Organisms Consciousness and Complex Behavior

    Directory of Open Access Journals (Sweden)

    Søren Ventegodt

    2006-01-01

    Full Text Available Deep quantum chemistry is a theory of deeply structured quantum fields carrying the biological information of the cell, making it able to remember, intend, represent the inner and outer world for comparison, understand what it “sees”, and make choices on its structure, form, behavior and division. We suggest that deep quantum chemistry gives the cell consciousness and all the qualities and abilities related to consciousness. We use geometric symbolism, which is a pre-mathematical and philosophical approach to problems that cannot yet be handled mathematically. Using Occam’s razor we have started with the simplest model that works; we presume this to be a many-dimensional, spiral fractal. We suggest that all the electrons of the large biological molecules’ orbitals make one huge “cell-orbital”, which is structured according to the spiral fractal nature of quantum fields. Consciousness of single cells, multi cellular structures as e.g. organs, multi-cellular organisms and multi-individual colonies (like ants and human societies can thus be explained by deep quantum chemistry. When biochemical activity is strictly controlled by the quantum-mechanical super-orbital of the cell, this orbital can deliver energetic quanta as biological information, distributed through many fractal levels of the cell to guide form and behavior of an individual single or a multi-cellular organism. The top level of information is the consciousness of the cell or organism, which controls all the biochemical processes. By this speculative work inspired by Penrose and Hameroff we hope to inspire other researchers to formulate more strict and mathematically correct hypothesis on the complex and coherence nature of matter, life and consciousness.

  1. Conservation Meets Militarisation in Kruger National Park: Historical Encounters and Complex Legacies

    Directory of Open Access Journals (Sweden)

    Elizabeth Lunstrum

    2015-01-01

    Full Text Available Drawing on environmental history and political ecology, this paper contributes to growing debates concerning military-environment encounters and conservation militarisation/securitisation by investigating the complex histories and legacies of these relations. Grounding my insights in South Africa's iconic Kruger National Park, I chart how encounters between environment and military/security activity over the last century offer a repeatedly contradictory picture: military activity, skills, and weapons have harmed wildlife and hence reinforced the need for its protection, and they have simultaneously been deployed in the name of such protection. Furthermore, some of these historical engagements failed to materialise as planned and, as such, provide insight into military-environment frictions as well as nature's ability to thwart militarised interventions. Yet other engagements thrived and resulted in the multi-layered militarisation of Kruger, as both protected area and strategic borderland. Several of these encounters have lived on to shape Kruger's current intensive militarisation tied to rhino poaching, both the state response and poaching itself. Past military activity, in fact, provides an arsenal of enabling factors for current poaching- and conservation-related militarised violence that ultimately proves harmful to conservation efforts.

  2. Accurate reproduction of 161 small-molecule complex crystal structures using the EUDOC program: expanding the use of EUDOC to supramolecular chemistry.

    Directory of Open Access Journals (Sweden)

    Qi Wang

    Full Text Available EUDOC is a docking program that has successfully predicted small-molecule-bound protein complexes and identified drug leads from chemical databases. To expand the application of the EUDOC program to supramolecular chemistry, we tested its ability to reproduce crystal structures of small-molecule complexes. Of 161 selected crystal structures of small-molecule guest-host complexes, EUDOC reproduced all these crystal structures with guest structure mass-weighted root mean square deviations (mwRMSDs of <1.0 A relative to the corresponding crystal structures. In addition, the average interaction energy of these 161 guest-host complexes (-50.1 kcal/mol was found to be nearly half of that of 153 previously tested small-molecule-bound protein complexes (-108.5 kcal/mol, according to the interaction energies calculated by EUDOC. 31 of the 161 complexes could not be reproduced with mwRMSDs of <1.0 A if neighboring hosts in the crystal structure of a guest-host complex were not included as part of the multimeric host system, whereas two of the 161 complexes could not be reproduced with mwRMSDs of <1.0 A if water molecules were excluded from the host system. These results demonstrate the significant influence of crystal packing on small molecule complexation and suggest that EUDOC is able to predict small-molecule complexes and that it is useful for the design of new materials, molecular sensors, and multimeric inhibitors of protein-protein interactions.

  3. Understanding FVIII/VWF complex--report from a symposium of XXIX WFH meeting 2010.

    Science.gov (United States)

    Gringeri, A; Ofosu, F A; Grancha, S; Oldenburg, J; Ewing, N P; Federici, A B

    2012-05-01

    von Willebrand factor (VWF) has the capacity to form a complex with factor VIII (FVIII) which may modulate the immunogenicity of FVIII. It has been proposed that a significant fraction of recombinant FVIII (rFVIII) is unable to bind VWF. In an experimental model studied at the McMaster University in Canada, this VWF-unbound rFVIII fraction showed no coagulant function. Sulphation of FVIII tyrosine (Tyr) 1680 has been reported as essential for the interaction with VWF. In a study performed at the Grifols and CNS-CSIC in Spain, Tyr1680 sulphation was observed to be incomplete in rFVIII and complete in plasma-derived FVIII (pdFVIII). This could explain the incapability of some rFVIII molecules to bind VWF. Experience with immune tolerance induction (ITI) at the Bonn Haemophilia Centre indicates that only eradication of FVIII inhibitors allows safe haemostasis control and the option of prophylactic treatment. Various clinical trials were planned to evaluate the clinical role VWF-containing FVIII concentrates (FVIII/VWF). RES.I.ST (an acronym for REScue Immunotolerance STudy) is an international, prospective study aimed at assessing whether FVIII/VWF can induce ITI in high-risk haemophilia patients (RES.I.ST naïve) and whether patients who previously failed ITI with FVIII alone can be rescued with FVIII/VWF (RES.I.ST experienced). Enrolment started in November 2009. In the FAIReSt.Will (Fanhdi and Alphanate Italian Retrospective Study in Willebrand disease) study, 120 von Willebrand disease (VWD) patients treated with Fanhdi(®) or Alphanate(®) were retrospectively analysed. Efficacy was excellent and no side effects were reported. The ongoing PRO.Will study is a prospective, multicenter trial aimed at assessing the efficacy, safety and pharmacoeconomics of secondary long-term prophylaxis in patients with severe inherited VWD.

  4. Synthesis and Properties of Chelating N-Heterocyclic Carbene Rhodium(I) Complexes: Synthetic Experiments in Current Organometallic Chemistry

    Science.gov (United States)

    Mata, Jose A.; Poyatos, Macarena; Mas-Marza, Elena

    2011-01-01

    The preparation and characterization of two air-stable Rh(I) complexes bearing a chelating N-heterocyclic carbene (NHC) ligand is described. The synthesis involves the preparation of a Ag(I)-NHC complex and its use as carbene transfer agent to a Rh(I) precursor. The so obtained complex can be further reacted with carbon monoxide to give the…

  5. 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

  6. Coordination chemistry of a low-coordinate non-metal element: the case of electrophilic terminal phosphinidene complexes.

    Science.gov (United States)

    Villalba Franco, José Manuel; Schnakenburg, Gregor; Espinosa Ferao, Arturo; Streubel, Rainer

    2016-09-21

    3-Imino-azaphosphiridine complex 1 reacts with carbon monoxide to give 1,3-azaphosphetidinone complex 2, whereas with isocyanides 3a,b substitution occurred to yield complexes 4a,b. Oxidation of 1 using elemental sulfur afforded the first 1,3,2-thiazaphosphetidine-4-imine complex 5. DFT calculations provide insight into a manifold of pathways based on a common intermediate, a carbodiimide-to-phosphinidene complex, leading to P-N and P-C bond insertion products as well as ligand substitution products. PMID:27527532

  7. Main group chemistry of 9-hydroxophenalenone: Syntheses and structural characterization of the alkaline earth and zinc complexes

    Indian Academy of Sciences (India)

    Arup Mukherjee; Prinson P Samuel; Carola Schulzke; Swadhin K Mandal

    2014-09-01

    Herein, we report the synthesis and characterization of 9-hydroxophenalenone based alkaline earth and zinc complexes.The reaction of 9-hydroxophenalenone (HO,O-PLY (1)) with one equivalent of KN(SiMe3)2 and MI2 in THF yields heteroleptic complexes [(O,O-PLY)M(THF)]I [M= Mg (2), Ca (3), Sr (4), Ba (5); n = 1-4], while use of two equivalents of KN(SiMe3)2 in THF (with respect to PLY) produces homoleptic complex (O,O-PLY)2Mg(THF)2 (6). Moreover, reaction between two equivalents of 1 with one equivalent of ZnMe2 in THF produces complex (O,O-PLY)2Zn(THF)2 (7). All these complexes were characterized by NMR spectroscopy and elemental analyses. The solid state structures of complexes 2, 6 and 7 were established by single crystal X-ray diffraction analysis.

  8. Level rings arising from meet-distributive meet-semilattices

    OpenAIRE

    Herzog, Juergen; Hibi, Takayuki

    2006-01-01

    The homogenized ideal dual complex of an arbitrary meet-semilattice is introduced and described explicitly. Meet-distributive meet-semilattices whose homogenized ideal dual complex is level are characterized.

  9. Synthesis of Well-Defined Copper "N"-Heterocyclic Carbene Complexes and Their Use as Catalysts for a "Click Reaction": A Multistep Experiment that Emphasizes the Role of Catalysis in Green Chemistry

    Science.gov (United States)

    Ison, Elon A.; Ison, Ana

    2012-01-01

    A multistep experiment for an advanced synthesis lab course that incorporates topics in organic-inorganic synthesis and catalysis and highlights green chemistry principles was developed. Students synthesized two "N"-heterocyclic carbene ligands, used them to prepare two well-defined copper(I) complexes and subsequently utilized the complexes as…

  10. A new diamantane functionalized tris(aryloxide) ligand system for small molecule activation chemistry at reactive uranium complexes

    Energy Technology Data Exchange (ETDEWEB)

    Lam, O.P.; Heinemann, F.W.; Meyer, K. [Department of Chemistry and Pharmacy, Inorganic Chemistry, University Erlangen-Nuremberg, Erlangen (Germany); Lam, O.P. [University of California, San Diego, Department of Chemistry and Biochemistry, La Jolla, CA (United States)

    2010-06-15

    The diamantane functionalized triazacyclononane ligand ({sup Dia}ArOH){sub 3}tacn (L{sub 3}) has been synthesized and the reactivity of its U(III) metallated product [(({sup Dia}ArO){sub 3}tacn)U] (1) has been explored. Complex 1 promotes dichloromethane and azido-trimethyl-silane activation to generate U(IV) complex [(({sup Dia}ArO){sub 3}tacn)U(Cl)] (2) and U(V) complex [(({sup Dia}ArO){sub 3}tacn)U(NTMS)] (3), respectively. Spectroscopic investigations of complexes 1, 2, and 3 will be discussed, along with molecular structures where possible. (authors)

  11. A new diamantane functionalized tris(aryloxide) ligand system for small molecule activation chemistry at reactive uranium complexes

    International Nuclear Information System (INIS)

    The diamantane functionalized triazacyclononane ligand (DiaArOH)3tacn (L3) has been synthesized and the reactivity of its U(III) metallated product [((DiaArO)3tacn)U] (1) has been explored. Complex 1 promotes dichloromethane and azido-trimethyl-silane activation to generate U(IV) complex [((DiaArO)3tacn)U(Cl)] (2) and U(V) complex [((DiaArO)3tacn)U(NTMS)] (3), respectively. Spectroscopic investigations of complexes 1, 2, and 3 will be discussed, along with molecular structures where possible. (authors)

  12. Constitutional dynamic chemistry: bridge from supramolecular chemistry to adaptive chemistry.

    Science.gov (United States)

    Lehn, Jean-Marie

    2012-01-01

    Supramolecular chemistry aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the investigation of chemical systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems. Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.CDC introduces a paradigm shift with respect to constitutionally static chemistry. The latter relies on design for the generation of a target entity, whereas CDC takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.The merging of the features: -information and programmability, -dynamics and reversibility, -constitution and structural diversity, points to the emergence of adaptive and evolutive chemistry, towards a chemistry of complex matter.

  13. Does vegetation complexity affect host plant chemistry, and thus multitrophic interactions, in a human-altered landscape?

    Science.gov (United States)

    Wäschke, Nicole; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2015-09-01

    Anthropogenic land use may shape vegetation composition and affect trophic interactions by altering concentrations of host plant metabolites. Here, we investigated the hypotheses that: (1) plant N and defensive secondary metabolite contents of the herb Plantago lanceolata are affected by land use intensity (LUI) and the surrounding vegetation composition (=plant species richness and P. lanceolata density), and that (2) changes in plant chemistry affect abundances of the herbivorous weevils Mecinus pascuorum and Mecinus labilis, as well as their larval parasitoid Mesopolobus incultus, in the field. We determined plant species richness, P. lanceolata density, and abundances of the herbivores and the parasitoid in 77 grassland plots differing in LUI index in three regions across Germany. We also measured the N and secondary metabolite [the iridoid glycosides (IGs) aucubin and catalpol] contents of P. lanceolata leaves. Mixed-model analysis revealed that: (1) concentrations of leaf IGs were positively correlated with plant species richness; leaf N content was positively correlated with the LUI index. Furthermore: (2) herbivore abundance was not related to IG concentrations, but correlated negatively with leaf N content. Parasitoid abundance correlated positively only with host abundance over the three regions. Structural equation models revealed a positive impact of IG concentrations on parasitoid abundance in one region. We conclude that changes in plant chemistry due to land use and/or vegetation composition may affect higher trophic levels and that the manifestation of these effects may depend on local biotic or abiotic features of the landscape. PMID:25986560

  14. 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.

  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. Syntheses and Characterization of Ruthenium(II) Tetrakis(pyridine)complexes: An Advanced Coordination Chemistry Experiment or Mini-Project

    Science.gov (United States)

    Coe, Benjamin J.

    2004-01-01

    An experiment for third-year undergraduate a student is designed which provides synthetic experience and qualitative interpretation of the spectroscopic properties of the ruthenium complexes. It involves the syntheses and characterization of several coordination complexes of ruthenium, the element found directly beneath iron in the middle of the…

  17. The redox chemistry of niobium(V) fluoro and oxofluoro complexes in LiF-NaF-KF melts

    DEFF Research Database (Denmark)

    Matthiesen, Flemming; Christensen, Erik; Barner, Jens H. Von;

    1996-01-01

    The electrochemical behavior of niobium(V) fluoro and oxofluoro complexes in eutectic LiF-NaF-KF (FLINAK) melts at 700 degrees C has been studied by cyclic voltammetry. The fluoro complexes NbF72-, introduced into the melt by the addition of K2NbF7, can be reduced to niobium metal in two reversible...

  18. Reports from the award symposia hosted by the American Chemical Society, Division of Carbohydrate Chemistry at the 245th American Chemical Society National Meeting.

    Science.gov (United States)

    Huang, Xuefei; Vocadlo, David J

    2013-07-19

    We would like to congratulate all of the award winners for the well deserved honor. The award symposia provided a snapshot of some of the state-of-the-art research at the interface between chemistry and biology in the glycoscience field. The presentations serve as prime examples of the increasing integration of chemical and biological research in the area of glycoscience and how tools of chemistry can be applied to answer interesting, important, and fundamental biological questions. We look forward to many more years of exciting developments in the chemistry and chemical biology of glycoscience and anticipate improved tools and approaches will drive major advances while also spurring interests in the wider field.

  19. Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts; Reunion de la Societe Geologique de France - Uranium: geologie, geophysique, chimie. Recueil des resumes

    Energy Technology Data Exchange (ETDEWEB)

    Zakari, A.A.; Mima, S.; Bidaud, A.; Criqui, P.; Menanteau, P.; David, S.; Pagel, M.; Chagnes, A.; Cote, G.; Courtaud, B.; Thiry, J.; Miehe, J.M.; Gilbert, F.; Cuney, M.; Bruneton, P.; Ewington, D.; Vautrin-Ul, C.; Cannizzo, C.; Betelu, S.; Chausse, A.; Ly, J.; Bourgeois, D.; Maynadie, J.; Meyer, D.; Clavier, N.; Costin, D.T.; Cretaz, F.; Szenknect, S.; Ravaux, J.; Poinssot, C.; Dacheux, N.; Durupt, N.; Blanvillain, J.J.; Geffroy, F.; Aparicio, B.; Dubessy, J.; Nguyen-Trung, C.; Robert, P.; Uri, F.; Beaufort, D.; Lescuyer, J.L.; Morichon, E.; Allard, T.; Milesi, J.P.; Richard, A.; Rozsypal, C.; Mercadier, J.; Banks, D.A.; Boiron, M.C.; Cathelineau, M.; Dardel, J.; Billon, S.; Patrier, P.; Wattinne, A.; Vanderhaeghe, O.; Fabre, C.; Castillo, M.; Salvi, S.; Beziat, D.; Williams-Jones, A.E.; Trap, P.; Durand, C.; Goncalves, P.; Marquer, D.; Feybesse, J.L.; Richard, Y.; Orberger, B.; Hofmann, A.; Megneng, M.; Orberger, B.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Perdicakis, M.; Prignon, N.; Toe, W.; Andre-Mayer, A.S.; Eglinger, A.; Jordaan, T.; Hocquet, S.; Ledru, P.; Selezneva, V.; Vendryes, G.; Lach, P.; Cuney, M.; Mercadier, J.; Brouand, M.; Duran, C.; Seydoux-Guillaume, A.M.; Bingen, B.; Parseval, P. de; Guillaume, D.; Bosse, V.; Paquette, J.L.; Ingrin, J.; Montel, J.M.; Giot, R.; Maucotel, F.; Hubert, S.; Gautheron, C.; Tassan-Got, L.; Pagel, M.; Barbarand, J.; Cuney, M.; Lach, P.; Bonhoure, J.; Leisen, M.; Kister, P.; Salaun, A.; Villemant, B.; Gerard, M.; Komorowski, J.C.; Michel, A.; Riegler, T.; Tartese, R.; Boulvais, P.; Poujols, M.; Gloaguen, E.; Mazzanti, M.; Mougel, V.; Nocton, G.; Biswas, B.; Pecaut, J.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Galoisy, L.; Calas, G.; Fayek, M.

    2010-11-15

    This document brings together the abstracts of the 39 presentations given at this meeting days on uranium, organized by the French geological society, and dealing with: 1 - Prospective study of the electronuclear technological transition; 2 - The front-end of the nuclear cycle: from the molecule to the process; 3 - Geophysics: recent changes; 4 - Use of well logging in uranium exploration; 5 - Genetical classification of thorium deposits; 6 - Genetical nomenclature of uranium sources; 7 - Uranium deposits linked to a Proterozoic discordance - retrospective; 8 - The use of spectral analysis techniques in uranium exploration: real-time mapping of clay alteration features; 9 - Development of functionalized silk-screened carbon electrodes for the analysis of uranium trace amounts; 10 - Study of the actinides solvation sphere in organic environment; 11 - Thermodynamic of uraniferous phases of interest for the nuclear cycle; 12 - Heap leaching of marginal minerals at Somair: from lab studies to the production of 700 t of uranium/year; 13 - Agglomeration phenomenology and role of iron in uranium heap leaching; 14 - Chloride uranyl complexes up to 300 deg. C along the saturation vapour curve: Raman spectroscopy analysis and metallogenic consequences; 15 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): vertical variability of argillaceous weathering; 16 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): contribution of irradiation defects in clays to the tracing of past uranium migrations; 17 - Uranium concentrations in mineralizing fluids of the Athabasca basin: analytical and experimental approach; 18 - Paleo-surfaces and metallic rooting: the autochthonous uranium of pre-Athabasca paleo-alterites, Canada; 19 - Distribution of argillaceous parageneses in the Imouraren deposit - Niger; 20 - Heat flux and radioelements concentration (U, Th, K) of precambrian basements: implications in terms of crust growth mechanisms, paleo

  20. Charnockitic ortho gneisses and mafic granulite s of the Cerro Olivo complex, south-east Uruguay, Part 2: lithogeochemistry, mineral o chemistry and thermo barometry

    International Nuclear Information System (INIS)

    The Cerro Olivo complex in SE-Uruguay shows different kinds of orthogneisses containing biotite, amphibole and/or orthopyroxene-biotite (charnockitic gneisses). Minor occurrences of mafic granulites are associated. They include low and high pressure kinds. We present the lithogeochemistry and compared mineral chemistry analyses of both the charnockitic orthogneisses and the mafic rocks. Theres i a calc-alkaline geochemical affinity of the biotite-bearing and charnockitic gneisses, while the mafic rocks could derive from tholeitic gabbros. These results allow discrininatieg two kinds of mafic rocks: Low and hight MgO contents, both representing respectively garnet-bearing and garnet-free mafic granulites. The orthopyroxene in the Opx-Bt orthogneisses in FE-rich while MgO-rich mafic rocks show hypersthenes. The thermobarometric data of mafic granulites show temperatures higher than 850°C and two contrasting mineral assemblages, one formed by ∼ 1 Kbar and 770° - 800°C (pre-M). and the other by 5.5 Kbar and 680-700° (M). The mineral chemistry suggests the occurrence of contrasting protoliths to explain the stability of two different mineral associations

  1. Iridium Cyclometalated Complexes in Host-Guest Chemistry: A Strategy for Maximizing Quantum Yield in Aqueous Media.

    Science.gov (United States)

    Alrawashdeh, Lubna R; Cronin, Michael P; Woodward, Clifford E; Day, Anthony I; Wallace, Lynne

    2016-07-01

    The weaker emission typically seen for iridium(III) cyclometalated complexes in aqueous medium can be reversed via encapsulation in cucurbit[10]uril (Q[10]). The Q[10] cavity is shown to effectively maximize quantum yields for the complexes, compared to any other medium. This may provide significant advantages for a number of sensor applications. NMR studies show that the complexes are accommodated similarly within the host molecule, even with cationic substituents attached to the ppy ligands, indicating that the hydrophobic effect is the dominant driving force for binding. Cavity-encapsulated 1:1 host-guest species dominate the emission, but 1:2 species are also indicated, which also give some enhancement of intensity. Results demonstrate that the enhancement is due primarily to much lower rates of nonradiative decay but also suggest that the encapsulation can cause a change in character of the emitting state.

  2. Iridium Cyclometalated Complexes in Host-Guest Chemistry: A Strategy for Maximizing Quantum Yield in Aqueous Media.

    Science.gov (United States)

    Alrawashdeh, Lubna R; Cronin, Michael P; Woodward, Clifford E; Day, Anthony I; Wallace, Lynne

    2016-07-01

    The weaker emission typically seen for iridium(III) cyclometalated complexes in aqueous medium can be reversed via encapsulation in cucurbit[10]uril (Q[10]). The Q[10] cavity is shown to effectively maximize quantum yields for the complexes, compared to any other medium. This may provide significant advantages for a number of sensor applications. NMR studies show that the complexes are accommodated similarly within the host molecule, even with cationic substituents attached to the ppy ligands, indicating that the hydrophobic effect is the dominant driving force for binding. Cavity-encapsulated 1:1 host-guest species dominate the emission, but 1:2 species are also indicated, which also give some enhancement of intensity. Results demonstrate that the enhancement is due primarily to much lower rates of nonradiative decay but also suggest that the encapsulation can cause a change in character of the emitting state. PMID:27315543

  3. Making Visible the Complexities of Problem Solving: An Ethnographic Study of a General Chemistry Course in a Studio Learning Environment

    Science.gov (United States)

    Kalainoff, Melinda Zapata

    Studio classrooms, designed such that laboratory and lecture functions can occur in the same physical space, have been recognized as a promising contributing factor in promoting collaborative learning in the sciences (NRC, 2011). Moreover, in designing for instruction, a critical goal, especially in the sciences and engineering, is to foster an environment where students have opportunities for learning problem solving practices (NRC, 2012a). However, few studies show how this type of innovative learning environment shapes opportunities for learning in the sciences, which is critical to informing future curricular and instructional designs for these environments. Even fewer studies show how studio environments shape opportunities to develop problem solving practices specifically. In order to make visible how the learning environment promotes problem solving practices, this study explores problem solving phenomena in the daily life of an undergraduate General Chemistry studio class using an ethnographic perspective. By exploring problem solving as a sociocultural process, this study shows how the instructor and students co-construct opportunities for learning in whole class and small group interactional spaces afforded in this studio environment and how the differential demands on students in doing problems requires re-conceptualizing what it means to "apply a concept".

  4. Coordination chemistry of actinide elements: preparation of new uranium complexes with schiff bases and their characterization (Preprint No. CT-31)

    International Nuclear Information System (INIS)

    The Schiff bases, o-vanillin semicarbazone (oVSC) and 2-pyridine carboxaldehyde isonicotinoyl hydrazone (PCINH) have been prepared and their novel complexes with dioxouranium(VI) have been synthesized and characterized by IR spectra, elemental analysis and other physico-chemical techniques. (author)

  5. Proceedings of the 13. International Conference on the Properties of Water and Steam : steam, water and hydrothermal systems : physics and chemistry meeting the needs of the industry

    Energy Technology Data Exchange (ETDEWEB)

    Tremaine, P.R. [ed.] [Memorial Univ. of Newfoundland, St. John' s, NF (Canada); Hill, P.G. [ed.] [British Columbia Univ., Vancouver, BC (Canada); Irish, D.E. [ed.] [Waterloo Univ., ON (Canada); Balakrishnan, P.V. [eds.] [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

    2000-07-01

    This international conference focused on the physical and chemical properties of water, steam and aqueous systems. More than 140 presentations from nearly 200 scientists presented work in applied research in physics and chemistry of hydrothermal systems which are of particular importance to the thermal power industry. This year the conference expanded into new areas of pure and applied research related to water and aqueous solutions at temperature and pressure extremes. This application is useful to electric power cycle chemistry and other industrial technologies that involve the use of high-temperature and supercritical steam. The areas of basic science that were included were: spectroscopy, calorimetry, potentiometry, PVT measurements, molecular simulation studies of water, and solvated species in high-temperature or supercooled water. The areas of application were: power cycle chemistry, high-temperature aqueous technologies that apply to new steam cycles, use of high-temperature water and supercritical steam in chemical and metallurgical processes, supercritical destruction of toxic wastes, and hydrothermal geochemistry and hydrometallurgy. refs., tabs., figs.

  6. Optically active tetra-tert-butyl-P(5)-deltacyclene epimers: preparation, spectroscopy, dynamic equilibriums, H/D exchange, and transition-metal complex chemistry.

    Science.gov (United States)

    Rohwer, Lars; Höhn, Christine; Autschbach, Jochen; Bauer, Walter; Heinemann, Frank W; Huguet Torrell, Sergi; Keller, Irene; Shubina, Tatyana E; Steffen, Jacob; Zenneck, Ulrich

    2014-05-01

    -metal complex fragment. Such ligand flexibility is regularly observed in metalloenzymes, but is a very rare case in classical and organometallic complex chemistry. PMID:24677381

  7. Zircon chemistry and magma mixing, SE China: In-situ analysis of Hf isotopes, Tonglu and Pingtan igneous complexes

    Science.gov (United States)

    Griffin, W. L.; Wang, Xiang; Jackson, S. E.; Pearson, N. J.; O'Reilly, Suzanne Y.; Xu, Xisheng; Zhou, Xinmin

    2002-04-01

    Field relations and whole-rock geochemistry indicate that magma mixing has been important in the genesis of the late Mesozoic I-type igneous complexes at Pingtan and Tonglu in SE China. Morphological and trace-element studies of zircon populations in rocks from each of these complexes have defined several distinct growth stages [Mineral. Mag. (2001)]. In-situ LAM-MC-ICPMS microanalysis shows large variations in 176Hf/ 177Hf (up to 15 ɛHf units) between zircons of different growth stages within a single rock, and between zones within single zircon grains (up to 9 ɛHf units). These variations suggest that each of the observed magmas in both complexes developed through hybridisation of ≥2 magmas with different sources. Although this mixing has produced similar Sr and Nd isotopic compositions in the different rock types of each complex, the zircons have functioned as "tape recorders" and have preserved details of the assembly of the different magmas. In the Tonglu complex the most primitive magma is a mafic monzonite (preserved as enclaves), whose isotopic composition suggests derivation from the lower crust; rhyodacites, rhyolites and quartz diorites reflect the mixing of the monzonite with ≥2 more felsic magmas, derived from older crustal materials. In the Pingtan complex, zircons in a quartz diorite enclave suggest mixing between a crustal magma and a more primitive mantle-derived component. Zircons from granites and granodiorite enclaves indicate mixing between the quartz diorite and more felsic melts with lower 176Hf/ 177Hf. Major changes in 176Hf/ 177Hf correlate with discontinuous changes in the trace-element composition and morphology of the zircons, in particular the development of sector zoning that suggests rapid disequilibrium crystallisation. We suggest that the magma mixing recorded by the changes in 176Hf/ 177Hf occurred during transport in magma conduits. The in-situ analysis of Hf-isotopic stratigraphy in zircons is a new and powerful tool for

  8. Preparation of a N-Heterocyclic Carbene Nickel(II) Complex: Synthetic Experiments in Current Organic and Organometallic Chemistry

    Science.gov (United States)

    Ritleng, Vincent; Brenner, Eric; Chetcuti, Michael J.

    2008-01-01

    A four-part experiment that leads to the synthesis of a cyclopentadienyl chloro-nickel(II) complex bearing a N-heterocyclic carbene (NHC) ligand is presented. In the first part, the preparation of 1,3-bis-(2,4,6-trimethylphenyl)imidazolium chloride (IMes[middle dot]HCl) in a one-pot procedure by reaction of 2,4,6-trimethylaniline with…

  9. Solid-state and solution-state coordination chemistry of lanthanide(III) complexes with α-hydroxyisobutyric acid.

    Science.gov (United States)

    Chen, Xiao-Yan; Goff, George S; Ewing, William C; Scott, Brian L; Runde, Wolfgang

    2012-12-17

    Despite the wide range of applications of α-hydroxyisobutyric acid (HIBA) in biochemical processes, pharmaceutical formulations, and group and elemental separations of lanthanides and actinides, the structures and geometries of lanthanide-HIBA complexes are still not well understood. We reacted HIBA with lanthanides in aqueous solution at pH = 5 and synthesized 14 lanthanide-HIBA complexes of the formula [Ln(HIBA)(2)(H(2)O)(2)](NO(3))·H(2)O (Ln = La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8), Dy (9), Ho (10), Er (11), Tm (12), Yb (13), Lu (14)), isolating single crystals (1-7, 10, and 11) and powders (8, 9, and 12-14). Both single-crystal and powder X-ray diffraction studies reveal a two-dimensional extended structure across the entire lanthanide series. The environment around the eight-coordinated Ln(III) atom is best described as a distorted dodecahedron, where HIBA acts as a monoanionic tridentate ligand with one carboxylato oxygen atom and one hydroxyl oxygen atom chelating to one Ln(III) center. The carboxylato oxygen atom from a second HIBA ligand bridges to a neighboring Ln(III) atom to form a two-dimensional extended structure. While the coordination mode for HIBA is identical across the lanthanide series, three different structure types are found for La, Ce-Ho, and Er-Lu. Solution characterization using (13)C NMR further confirmed a single solution complex under the crystallization conditions. Raman and UV-vis-NIR absorbance and diffuse reflectance spectra of HIBA-Ln(III) complexes were also measured.

  10. A Systematic Study of Structure and E-H Bond Activation Chemistry by Sterically Encumbered Germylene Complexes.

    Science.gov (United States)

    Usher, Matthew; Protchenko, Andrey V; Rit, Arnab; Campos, Jesús; Kolychev, Eugene L; Tirfoin, Rémi; Aldridge, Simon

    2016-08-01

    A series of new germylene compounds has been synthesized offering systematic variation in the σ- and π-capabilities of the α-substituent and differing levels of reactivity towards E-H bond activation (E=H, B, C, N, Si, Ge). Chloride metathesis utilizing [(terphenyl)GeCl] proves to be an effective synthetic route to complexes of the type [(terphenyl)Ge(ERn )] (1-6: ERn =NHDipp, CH(SiMe3 )2 , P(SiMe3 )2 , Si(SiMe3 )3 or B(NDippCH)2 ; terphenyl=C6 H3 Mes2 -2,6=Ar(Mes) or C6 H3 Dipp2 -2,6=Ar(Dipp) ; Dipp=C6 H3 iPr2 -2,6, Mes=C6 H2 Me3 -2,4,6), while the related complex [{(Me3 Si)2 N}Ge{B(NDippCH)2 }] (8) can be accessed by an amide/boryl exchange route. Metrical parameters have been probed by X-ray crystallography, and are consistent with widening angles at the metal centre as more bulky and/or more electropositive substituents are employed. Thus, the widest germylene units (θ>110°) are found to be associated with strongly σ-donating boryl or silyl ancillary donors. HOMO-LUMO gaps for the new germylene complexes have been appraised by DFT calculations. The aryl(boryl)-germylene system [Ar(Mes) Ge{B(NDippCH)2 }] (6-Mes), which features a wide C-Ge-B angle (110.4(1)°) and (albeit relatively weak) ancillary π-acceptor capabilities, has the smallest HOMO-LUMO gap (119 kJ mol(-1) ). These features result in 6-Mes being remarkably reactive, undergoing facile intramolecular C-H activation involving one of the mesityl ortho-methyl groups. The related aryl(silyl)-germylene system, [Ar(Mes) Ge{Si(SiMe3 )3 }] (5-Mes) has a marginally wider HOMO-LUMO gap (134 kJ mol(-1) ), rendering it less labile towards decomposition, yet reactive enough to oxidatively cleave H2 and NH3 to give the corresponding dihydride and (amido)hydride. Mixed aryl/alkyl, aryl/amido and aryl/phosphido complexes are unreactive, but amido/boryl complex 8 is competent for the activation of E-H bonds (E=H, B, Si) to give hydrido, boryl and silyl products. The results of these reactivity studies

  11. Petrography and mineral chemistry of carbonatites and mica-rich rocks from the Araxa Complex (Alto Paranaiba Province, Brazil)

    Energy Technology Data Exchange (ETDEWEB)

    Traversa, Gianbosco; Morbidelli, Lucio; Ronca, Sara [Roma Univ. (Italy). Dipt. di Scienze della Terra; Gomes, Celso B.; Ruberti, Excelso [Sao Paulo Univ., SP (Brazil). Inst. de Geociencias].E-mail: cgomes@usp.br; Brotzu, Piero [Napoli Univ. (Italy). Dipt. di Scienze della Terra; Buraglini, Nicoletta [Catania Univ. (Italy). Dipt. di Scienza della Terra; Principato, Maria Speranza [Milano Univ. (Italy). Dipt. di Scienza della Terra

    2001-03-01

    The Araxa complex (16 km{sup 2}) comprises carbonatites forming a central core and a complex network of concentric and radial dykes as well as small veins; additionally, it includes mica-rich rocks, phoscorities and lamprophyres. Fenites also occur and rare represented by Proterozoic quartzites and schists of the Araxa Group. The petrographic study of 130 borehole samples indicates that the complex is basically made up by two rock-types, carbonatites and mica-rich rocks, and subordinately by a third unit of hybrid composition. Carbonatites range chemically in composition, the most abundant type being magnesio-carbonatites. Dolomite and calcite correspond to the chief constituents, but other carbonate phases, including the Ce-group RE minerals, are also recognized. phosphates and oxides are widespread accessories whereas silicate minerals consist of olivine, clinopyroxene, mica and amphibole. Mica-rich rocks are represented by abundant glimmeritic rocks and scare cumulitic phlogopite-, olivine-and diopside-bearing pyroxenites. Hybrid rocks mainly contain phlogopite and tetraferriphlopite as cumulus and intercumulus phases, respectively; carbonate minerals may also be found. Chemical data indicate that the carbonatities are strongly enriched in REE and have lower contents of Nb, Zr, V, Cr, Ni and Rb compared to the mica-rich rocks. The higher K, Nb and Zr contents of the latter rocks are believed to be related to metasomatic processes (glimmeritization) of the pyroxenites. Similar REE patterns for carbonatites and mica-rich rocks seem to suggest that they are related to a single parental magma, possibly of ijolitic composition. Steep LREE/HREE fractionation and high {sigma}REE content of some carbonatite samples would be explained by hydrothermal and supergenic processes. (author)

  12. Solid-state and solution-state coordination chemistry of lanthanide(III) complexes with (pyrazol-1-yl)acetic acid.

    Science.gov (United States)

    Chen, Xiao-Yan; Goff, George S; Scott, Brian L; Janicke, Michael T; Runde, Wolfgang

    2013-03-18

    As a precursor of carboxyl-functionalized task-specific ionic liquids (TSILs) for f-element separations, (pyrazol-1-yl)acetic acid (L) can be deprotonated as a functionalized pyrazolate anion to coordinate with hard metal cations. However, the coordination chemistry of L with f-elements remains unexplored. We reacted L with lanthanides in aqueous solution at pH = 5 and synthesized four lanthanide complexes of general formula [Ln(L)3(H2O)2]·nH2O (1, Ln = La, n = 2; 2, Ln = Ce, n = 2; 3, Ln = Pr, n = 2; 4, Ln = Nd, n = 1). All complexes were characterized by single crystal X-ray diffraction analysis revealing one-dimensional chain formations. Two distinct crystallographic structures are governed by the different coordination modes of carboxylate groups in L: terminal bidentate and bridging tridentate (1-3); terminal bidentate, bridging bidentate, and tridentate coordination in 4. Comparison of the solid state UV-vis-NIR diffuse reflectance spectra with solution state UV-vis-NIR spectra suggests a different species in solution and solid state. The different coordination in solid state and solution was verified by distinctive (13)C NMR signals of the carboxylate groups in the solid state NMR.

  13. 配位印迹聚合物在分析化学中的应用进展%Application Development of Complex Imprinted Polymer in Analytical Chemistry

    Institute of Scientific and Technical Information of China (English)

    黄健祥; 胡玉玲; 胡玉斐; 李攻科

    2012-01-01

    分子印迹聚合物(MIP)是一种对目标分子(模板分子)具有选择性结合能力的聚合物.配位印迹聚合物(CIP)是基于金属离子与功能单体、模板分子间配位作用的分子印迹聚合物,既沿袭了MIP的优点,又具有适用于极性环境等优点,在食品、环境、生物、医药等领域目标物的识别中有良好的应用潜力.本文介绍了CIP的原理和特点,综述了CIP在分析化学中的应用进展,展望了CIP的发展前景.%Molecularly imprinted polymer (MIP) has the selective binding ability for target molecule (template molecule). Based on the coordination among metal, functional monomer and template molecule, complex imprinted polymer (CIP) holds selectivity derived from MIP and has some specialties like being stable and effective in polar environment, which make a great potential of the recognition of target analytes in food, environmental, biological and pharmaceutical samples. In this paper, the characteristic of CIP was introduced. Its development of application in analytical chemistry was summarized. The foreground of complex imprinted technique was previewed.

  14. Green chemistry: principles and practice.

    Science.gov (United States)

    Anastas, Paul; Eghbali, Nicolas

    2010-01-01

    Green Chemistry is a relatively new emerging field that strives to work at the molecular level to achieve sustainability. The field has received widespread interest in the past decade due to its ability to harness chemical innovation to meet environmental and economic goals simultaneously. Green Chemistry has a framework of a cohesive set of Twelve Principles, which have been systematically surveyed in this critical review. This article covers the concepts of design and the scientific philosophy of Green Chemistry with a set of illustrative examples. Future trends in Green Chemistry are discussed with the challenge of using the Principles as a cohesive design system (93 references). PMID:20023854

  15. Uranium triamidoamine chemistry.

    Science.gov (United States)

    Gardner, Benedict M; Liddle, Stephen T

    2015-07-01

    Triamidoamine (Tren) complexes of the p- and d-block elements have been well-studied, and they display a diverse array of chemistry of academic, industrial and biological significance. Such in-depth investigations are not as widespread for Tren complexes of uranium, despite the general drive to better understand the chemical behaviour of uranium by virtue of its fundamental position within the nuclear sector. However, the chemistry of Tren-uranium complexes is characterised by the ability to stabilise otherwise reactive, multiply bonded main group donor atom ligands, construct uranium-metal bonds, promote small molecule activation, and support single molecule magnetism, all of which exploit the steric, electronic, thermodynamic and kinetic features of the Tren ligand system. This Feature Article presents a current account of the chemistry of Tren-uranium complexes.

  16. Investigating the Complex Chemistry of Functional Energy Storage Systems: The Need for an Integrative, Multiscale (Molecular to Mesoscale) Perspective

    Science.gov (United States)

    2016-01-01

    Electric energy storage systems such as batteries can significantly impact society in a variety of ways, including facilitating the widespread deployment of portable electronic devices, enabling the use of renewable energy generation for local off grid situations and providing the basis of highly efficient power grids integrated with energy production, large stationary batteries, and the excess capacity from electric vehicles. A critical challenge for electric energy storage is understanding the basic science associated with the gap between the usable output of energy storage systems and their theoretical energy contents. The goal of overcoming this inefficiency is to achieve more useful work (w) and minimize the generation of waste heat (q). Minimization of inefficiency can be approached at the macro level, where bulk parameters are identified and manipulated, with optimization as an ultimate goal. However, such a strategy may not provide insight toward the complexities of electric energy storage, especially the inherent heterogeneity of ion and electron flux contributing to the local resistances at numerous interfaces found at several scale lengths within a battery. Thus, the ability to predict and ultimately tune these complex systems to specific applications, both current and future, demands not just parametrization at the bulk scale but rather specific experimentation and understanding over multiple length scales within the same battery system, from the molecular scale to the mesoscale. Herein, we provide a case study examining the insights and implications from multiscale investigations of a prospective battery material, Fe3O4. PMID:27413781

  17. Thermally Induced Chemistry of Meteoritic Complex Organic Molecules: A New Heat-Diffusion Model for the Atmospheric Entry of Meteorites

    CERN Document Server

    Shingledecker, Christopher N

    2014-01-01

    Research over the past four decades has shown a rich variety of complex organic molecular content in some meteorites. This current study is an attempt to gain a better insight into the thermal conditions experienced by these molecules inside meteorites during atmospheric entry. In particular, we wish to understand possible chemical processes that can occur during entry and that might have had an effect on complex organic or prebiotic species that were delivered in this way to the early Earth. A simulation was written in Fortran to model heating by the shock generated during entry and the subsequent thermal diffusion inside the body of a meteorite. Experimental data was used for the thermal parameters of several types of meteorites, including iron-nickel and several classes of chondrites. A Sutton-Graves model of stagnation-point heating was used to calculate peak surface temperatures and an explicit difference formula was used to generate thermal diffusion profiles for both chondrites and iron-nickel type met...

  18. Mineral Chemistry of Melanite from Calcitic Ijolite, the Oka Carbonatite Complex, Canada:Implications for Multi-Pulse Magma Mixing

    Institute of Scientific and Technical Information of China (English)

    Wei Chen; Weiqi Zhang; Antonio Simonetti; Shaoyong Jiang

    2016-01-01

    Ti-rich garnet is found within calcitic ijolite from the Oka carbonatite complex in Can-ada, which is characterized by 58%–73% andradite component (2.12 wt.%–4.18 wt.% TiO2) and classi-fied as melanite. The garnet displays complex zoning and contains abundant high field strength ele-ments (HFSEs) and rare earth elements (REEs). Three groups (I, II, III) have been identified based on their petrographic nature. Compared to groups II and III, Group I garnet cores contain higher TiO2, MgO, HFSE, and REE and lower SiO2 abundances. The distinct chemical and petrographic signatures of the investigated garnets cannot be attributed to simple closed system crystallization, but they are consistent with the multi-pulse magma mixing. Combined with previously reported U-Pb ages for apa-tite from the calcitic ijolite, at least three stages of magma evolution and subsequent mixing have been involved in the generation of calcitic ijolite at Oka. The early-formed melt that generated Group I gar-net core was later mixed with at least two small-volume, more evolved melts. The intermediate stage melt formed the remaining garnet along with some pyroxene, calcite, nepheline, and apatite at 127±3.6 Ma. The youngest, most evolved melt generated the majority of pyroxene, calcite, nepheline, and apatite within the calcitic ijolite at 115±3.1 Ma.

  19. Chemistry by nanocatalysis: First example of a solid-supported RAPTA complex for organic reactions in aqueous medium

    KAUST Repository

    García-Garrido, Sergio E.

    2010-11-18

    A ruthenium-arene-PTA (RAPTA) complex has been supported for the first time on an inorganic solid, that is, silica-coated ferrite nanoparticles. The resulting magnetic material proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentration, environmentally friendly water as a reaction medium, with no use at all of organic solvent during or after the reactions, and microwaves as an alternative energy source renders the synthetic processes reported herein "truly" green and sustainable. RAPTA\\'s delight: A nano-RAPTA complex supported on silica-coated ferrite nanoparticles proved to be a general, very efficient and easily reusable catalyst for three synthetically useful organic transformations; selective nitrile hydration, redox isomerization of allylic alcohols, and heteroannulation of (Z)-enynols. The use of low metal concentrations, water as a reaction medium, and microwaves as an energy source renders these processes green and sustainable. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Investigating the Complex Chemistry of Functional Energy Storage Systems: The Need for an Integrative, Multiscale (Molecular to Mesoscale) Perspective.

    Science.gov (United States)

    Abraham, Alyson; Housel, Lisa M; Lininger, Christianna N; Bock, David C; Jou, Jeffrey; Wang, Feng; West, Alan C; Marschilok, Amy C; Takeuchi, Kenneth J; Takeuchi, Esther S

    2016-06-22

    Electric energy storage systems such as batteries can significantly impact society in a variety of ways, including facilitating the widespread deployment of portable electronic devices, enabling the use of renewable energy generation for local off grid situations and providing the basis of highly efficient power grids integrated with energy production, large stationary batteries, and the excess capacity from electric vehicles. A critical challenge for electric energy storage is understanding the basic science associated with the gap between the usable output of energy storage systems and their theoretical energy contents. The goal of overcoming this inefficiency is to achieve more useful work (w) and minimize the generation of waste heat (q). Minimization of inefficiency can be approached at the macro level, where bulk parameters are identified and manipulated, with optimization as an ultimate goal. However, such a strategy may not provide insight toward the complexities of electric energy storage, especially the inherent heterogeneity of ion and electron flux contributing to the local resistances at numerous interfaces found at several scale lengths within a battery. Thus, the ability to predict and ultimately tune these complex systems to specific applications, both current and future, demands not just parametrization at the bulk scale but rather specific experimentation and understanding over multiple length scales within the same battery system, from the molecular scale to the mesoscale. Herein, we provide a case study examining the insights and implications from multiscale investigations of a prospective battery material, Fe3O4.

  1. Investigating the Complex Chemistry of Functional Energy Storage Systems: The Need for an Integrative, Multiscale (Molecular to Mesoscale) Perspective.

    Science.gov (United States)

    Abraham, Alyson; Housel, Lisa M; Lininger, Christianna N; Bock, David C; Jou, Jeffrey; Wang, Feng; West, Alan C; Marschilok, Amy C; Takeuchi, Kenneth J; Takeuchi, Esther S

    2016-06-22

    Electric energy storage systems such as batteries can significantly impact society in a variety of ways, including facilitating the widespread deployment of portable electronic devices, enabling the use of renewable energy generation for local off grid situations and providing the basis of highly efficient power grids integrated with energy production, large stationary batteries, and the excess capacity from electric vehicles. A critical challenge for electric energy storage is understanding the basic science associated with the gap between the usable output of energy storage systems and their theoretical energy contents. The goal of overcoming this inefficiency is to achieve more useful work (w) and minimize the generation of waste heat (q). Minimization of inefficiency can be approached at the macro level, where bulk parameters are identified and manipulated, with optimization as an ultimate goal. However, such a strategy may not provide insight toward the complexities of electric energy storage, especially the inherent heterogeneity of ion and electron flux contributing to the local resistances at numerous interfaces found at several scale lengths within a battery. Thus, the ability to predict and ultimately tune these complex systems to specific applications, both current and future, demands not just parametrization at the bulk scale but rather specific experimentation and understanding over multiple length scales within the same battery system, from the molecular scale to the mesoscale. Herein, we provide a case study examining the insights and implications from multiscale investigations of a prospective battery material, Fe3O4. PMID:27413781

  2. Chemistry Notes

    Science.gov (United States)

    School Science Review, 1976

    1976-01-01

    Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)

  3. Colour Chemistry

    Science.gov (United States)

    Griffiths, J.; Rattee, I. D.

    1973-01-01

    Discusses the course offerings in pure color chemistry at two universities and the three main aspects of study: dyestuff chemistry, color measurement, and color application. Indicates that there exists a constant challenge to ingenuity in the subject discipline. (CC)

  4. Preliminary geology, mineral chemistry and diamond results from the C29/30 Candle Lake volcanic complex, Saskatchewan, Canada

    Science.gov (United States)

    Verigeanu, D.; Hetman, C. M.; Jellicoe, B.; Baumgartner, M. C.

    2009-11-01

    The C29/30 kimberlite is one of two diamondiferous kimberlites in the Candle Lake cluster located in east-central Saskatchewan, Canada, approximately 70 km from the Fort á la Corne kimberlite field. The kimberlites are hosted by a Cretaceous sequence of marine mudstone and shale of the Lower Colorado Group, and underlying siltstone and sandstone of the Mannville Group. This sequence overlies Paleozoic carbonates that were deposited over the Proterozoic crystalline basement. Based on the country rock stratigraphy and morphology of the body, C29/30 is inferred to be Cretaceous in age. The elongated kimberlite body has a lateral extent of approximately 2 km with the long axis oriented in a south-east to north-west direction and an estimated surface expression of 75.3 ha. The investigation of 47 drill cores suggests that this body is a single volcanic complex dominated by a single phase of volcaniclastic kimberlite that is characterised by absent to rare phlogopite within the groundmass of preserved juvenile clasts. Minor amounts of at least one other phase of kimberlite containing conspicuous groundmass phlogopite have also been documented. The subsurface shape of C29/30 is complex and is interpreted to result from a combination of explosive volcanic activity that formed two craters from separate feeder vents. The formation of the elongated trough is poorly understood. It may have formed by a fissure style eruption, or erosive processes related to the mass flow of material away from one of the craters or possible the collapse of an eruption column. The C29/30 kimberlite is similar to bodies of the Fort á la Corne kimberlite field with respect to country rock setting, pipe morphology and the dominant textural varieties present. This contribution presents a preliminary geological model of C29/30 based on data obtained from the drilling programmes completed in 2006, 2007 and 2008.

  5. 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

  6. 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....

  7. 77 FR 485 - Wind Plant Performance-Public Meeting on Modeling and Testing Needs for Complex Air Flow...

    Science.gov (United States)

    2012-01-05

    ... Testing Needs for Complex Air Flow Characterization AGENCY: Office of Energy Efficiency and Renewable... validation techniques for complex flow phenomena in and around off- shore and on-shore utility-scale wind... in regards to complex flow modeling and experimental validation. Ultimately, research in this...

  8. [Physico-chemistry of dinitrosyl iron complexes with thiol-containing ligands underlying their beneficial treatment of endometriosis].

    Science.gov (United States)

    Vanin, A F; Adamian, L V; Burgova, E N; Tkachev, N A

    2014-01-01

    Exogenous dinitrosyl iron complexes (DNIC) with thiol-containing ligands as NO and NO+ donors are capable of exerting both regulatory and cytotoxic effects on diverse biological processes similarly to those characteristic of endogenous nitric oxide. Regulatory activity of DNIC (vasodilation, hypotension, trombosis suppression, red blood cell elasticity increasing, skin wound healing acceleration, penile erection inducing, etc) is determined by their capacity of NO and NO+ transfer to biological targets of the latter (hemo- and thiol-containing proteins, respectively) due to higher affinity of the proteins for NO and NO+ than that of DNIC. Cytotoxic activity of DNIC is endowed with rapid DNIC decomposition under action of iron-chelating compounds resulting in appearance of NO and NO+ in cells and tissues in high amount. The latter mechanism is suggested to cause the blocking effect of DNIC as cytotoxic effectors on the development of benign endometrial tumors in rats with experimental endometriosis. It is also proposed that. a similar mechanism can operate causing at least a delay of malignant tumor proliferation under action of DNIC.

  9. Host-Guest Chemistry in the Gas Phase: Complex Formation of Cucurbit[6]uril with Proton-bound Water Dimer

    Science.gov (United States)

    Noh, Dong Hun; Lee, Shin Jung C.; Lee, Jong Wha; Kim, Hugh I.

    2014-03-01

    The hydration of cucurbit[6]uril (CB[6]) in the gas phase is investigated using electrospray ionization traveling wave ion mobility mass spectrometry (ESI-TWIM-MS). Highly abundant dihydrated and tetrahydrated species of diprotonated CB[6] are found in the ESI-TWIM-MS spectrum. The hydration patterns of the CB[6] ion and the dissociation patterns of the hydrated CB[6] ion indicate that two water molecules are bound to each other, forming a water dimer in the CB[6] complex. Ion mobility studies combined with the structures calculated by density functional theory suggest that the proton-bound water dimer is present as a Zundel-like structure in the CB[6] portal, forming a hydrogen bond network with carbonyl groups of the CB[6]. When a large guest molecule is bound to a CB[6] portal, water molecules cannot bind to the portal. In addition, the strong binding energy of the water dimer blocks the portal, hindering the insertion of the long alkyl chain of the guest molecule into the CB[6] cavity. With small alkali metal cations, such as Li+ and Na+, a single water molecule interacts with the CB[6] portal, forming hydrogen bonds with the carbonyl groups of CB[6]. A highly stable Zundel-like structure of the proton-bound water dimer or a metal-bound water molecule at the CB[6] portal is suggested as an initial hydration process for CB[6], which is only dissolved in aqueous solution with acid or alkali metal ions.

  10. Marcoule institute for separation chemistry - ICSM. Scientific report 2007 - 2010

    International Nuclear Information System (INIS)

    The mixed research unit 'Institute for Separation Chemistry' was created jointly by CEA, CNRS, University of Montpellier and Ecole Nationale superieure de Chimie de Montpellier has obtained authorisation to start experiments including a few grams of depleted uranium and natural thorium in January 2010. Last takeoff was from our theory group, who started in October 2009. But the unit 'Institut de Chimie separative de Marcoule' existed as a team scattered in several places in France since 2007. At that time, monthly meetings gathered people for full days of open discussion every month, as 'Point ICSM', where colleagues from R/D Departments of the centre of Marcoule composed half of the audience. Scientific activity began in 2007 with progressive joining of ICSM of team leaders, co-workers, technicians and students, today with 38 permanent staff and 29 nonpermanent scientists and students. Most of the staff joined ICSM after or before participating to the European practical summer school in Analytical and separation chemistry, hold yearly for a full week including practical sessions since the first edition 2006 in Montpellier. Resources in Uranium are scarce, if only the 235 isotope is used. Wastes related to nuclear energy production are potentially dangerous. Since fifty years, the chemistry associated to nuclear energy production always followed the principles of green chemistry. Permanent attention in devoted to closing the life-cycle of materials and fuel, minimize wastes and ascertain the acceptability by a society via knowledge of chemistry and physical chemistry involved in the chemistry used for separation. Developing knowledge in order to propose new separation processes is the central aim of the ICSM. Enlarging this central goal to surfaces of materials, sono-chemistry as an example of green chemistry, chemistry and physical chemistry specific to actinides complete this picture. Thus, the ICSM is devoted to chemistry at the service of the nuclear energy of

  11. 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.)

  12. Quest for new materials: Inorganic chemistry plays a crucial role

    Indian Academy of Sciences (India)

    J Gopalakrishnan; Rohini Mani

    2009-05-01

    There is an endless quest for new materials to meet the demands of advancing technology. Thus, we need new magnetic and metallic/semiconducting materials for spintronics, new low-loss dielectrics for telecommunication, new multi-ferroic materials that combine both ferroelectricity and ferromagnetism for memory devices, new piezoelectrics that do not contain lead, new lithium containing solids for application as cathode/anode/electrolyte in lithium batteries, hydrogen storage materials for mobile/transport applications and catalyst materials that can convert, for example, methane to higher hydrocarbons, and the list is endless! Fortunately for us, chemistry - inorganic chemistry in particular - plays a crucial role in this quest. Most of the functional materials mentioned above are inorganic non-molecular solids, while much of the conventional inorganic chemistry deals with isolated molecules or molecular solids. Even so, the basic concepts that we learn in inorganic chemistry, for example, acidity/basicity, oxidation/reduction (potentials), crystal field theory, low spin-high spin/inner sphere-outer sphere complexes, role of -electrons in transition metal chemistry, electron-transfer reactions, coordination geometries around metal atoms, Jahn-Teller distortion, metal-metal bonds, cation-anion (metal-nonmetal) redox competition in the stabilization of oxidation states - all find crucial application in the design and synthesis of inorganic solids possessing technologically important properties. An attempt has been made here to illustrate the role of inorganic chemistry in this endeavour, drawing examples from the literature as well as from the research work of my group.

  13. Complexity

    CERN Document Server

    Gershenson, Carlos

    2011-01-01

    The term complexity derives etymologically from the Latin plexus, which means interwoven. Intuitively, this implies that something complex is composed by elements that are difficult to separate. This difficulty arises from the relevant interactions that take place between components. This lack of separability is at odds with the classical scientific method - which has been used since the times of Galileo, Newton, Descartes, and Laplace - and has also influenced philosophy and engineering. In recent decades, the scientific study of complexity and complex systems has proposed a paradigm shift in science and philosophy, proposing novel methods that take into account relevant interactions.

  14. The coordination chemistry of boron porphyrin complexes B2OX2 (TYPP) (X = OH, F; Y = Cl, CH3) and their chemical reactivities

    Indian Academy of Sciences (India)

    G I Cárdenas-Jirón; F Espinoza-Leyton; T L Sordo

    2005-09-01

    The structure and coordination chemistry of boron porphyrin complexes B2OX2 (TYPP) (X = OH, F; Y = Cl, CH3) in connection with its chemical reactivity are analyzed at ab initio density functional theory B3LYP/6-31G∗ and restricted Hartree-Fock RHF/6-31G∗ levels of theory. Global reactivity and local selectivity descriptors are used as adequate tools to analyze the isomerism effect ( or isomer) and the substitution effect (X: in axial ligand; or Y: in porphyrin ligand). In all the cases, we find that the conformation is the most stable one, in agreement with X-ray results, and that a principle of maximum hardness in the isomerism analysis is fullfilled. In the substitution analysis, we find that the three global reactivity indexes (, , ) and the two local reactivity indexes (, electrostatic potential) used in this paper predict the same trend when an electron-withdrawing substituent is replaced by an electron donor. Finally, we show that substitution in the porphyrin ligand is slightly more significant than that in the axial ligand.

  15. Synthesis of P-stereogenic diarylphosphinic amides by directed lithiation: transformation into tertiary phosphine oxides via methanolysis, aryne chemistry and complexation behaviour toward zinc(ii).

    Science.gov (United States)

    del Águila-Sánchez, Miguel A; Navarro, Yolanda; García López, Jesús; Guedes, Guilherme P; López Ortiz, Fernando

    2016-02-01

    The highly diastereoselective synthesis of P-stereogenic phosphinic amides via directed ortho lithiation (DoLi) of (SC)-P,P-diphenylphosphinic amides with t-BuLi followed by electrophilic quench reactions is described. Functionalised derivatives containing a wide variety of ortho substituents (Cl, Br, I, OH, N3, SiMe3, SnMe3, P(O)Ph2, Me, allyl, (t)BuOCO) have been prepared in high yields with diastereomeric ratios up to 98 : 2. The X-ray diffraction structure of the ortho-stannylated and ortho-iodo compounds showed that the pro-S P-phenyl ring was stereoselectively ortho-deprotonated by the organolithium base. The usefulness of the method is supported by two key transformations, the synthesis of P-stereogenic methyl phosphinates through replacement of the chiral auxiliary by a methoxy group and the first example of the insertion of benzyne into the P-N bond of a P-stereogenic phosphinic amide. A DFT study of this reaction showed that the insertion proceeds through a [2 + 2] cycloaddition and a subsequent ring-opening with retention of the P-configuration. Explorative coordination chemistry of the new P-stereogenic ligands provided access to a chiral phosphinic amide-phosphine oxide Zn(ii) complex, the crystal structure of which is reported. PMID:26370566

  16. Meeting the complex needs of urban youth and their families through the 4Rs 2Ss Family Strengthening Program: The "real world" meets evidence-informed care.

    Science.gov (United States)

    Small, Latoya; Jackson, Jerrold; Gopalan, Geetha; McKay, Mary McKernan

    2015-07-01

    Youth living in poverty face compounding familial and environmental challenges in utilizing effective community mental health services. They have ongoing stressors that increase their dropout rate in mental health service use. Difficulties also exist in staying engaged in services when they are involved with the child welfare system. This study examines the 4Rs 2Ss Family Strengthening Program, developed across four broad conceptual categories related to parenting skills and family processes that form a multiple family group service delivery approach. A total of 321 families were enrolled in this randomized intervention study, assigned to either the 4Rs 2Ss Family Strengthening Program or standard care services. Caregivers and their children randomly assigned to the experimental condition received a 16 week multiple family group intervention through their respective outpatient community mental health clinic. Data was collected at baseline, midtest (8 weeks), posttest (16 weeks), and 6 month follow-up. Major findings include high engagement in the 4Rs 2Ss Family Strengthening Program, compared to standard services. Although child welfare status is not related to attendance, family stress and parental depression are also related to participant engagement in this multiple family group intervention. Involvement in the 4Rs 2Ss Family Strengthening Program resulted in improved effects for child behaviors. Lastly, no evidence of moderation effects on family stress, child welfare involvement, or parental needs were found. The 4Rs 2Ss Family Strengthening Program appeared able to engage families with more complex "real world" needs.

  17. The Complex Stratigraphy of the Highland Crust in the Serenitatis Region of the Moon Inferred from Mineral Fragment Chemistry

    Science.gov (United States)

    Ryder, Graham; Norman, Marc D.; Taylor, G. Jeffrey

    1997-01-01

    rocks do not contribute significantly to the fragment population. Nor do ferroan anorthosites contribute more than a tiny part of even the plagiociase fragment population. A few mineral fragments that are consistent with the cryptic low-K Fra Mauro chemical component were found, and these appear to be from gabbroic sources. The mineral fragment populations cannot be mixed in their observed proportions to produce the whole rock composition, because the fragments are more refractory and deficient in Ti, P, and alkalis. A preferential contribution to the melt from a rock similar to sodic ferrogabbro can partly resolve the discrepancy. The population of mineral fragments requires a very diverse population of igenous rocks that are not all related to each other, demonstrating the existence of a complex crust built of numerous separate igneous plutons. Many of these plutons may have crystallized at shallow depths. The chemical composition of the melt breccias, in combination with the mineral fragment data and an understanding of the cratering process, suggests that the deepest crust sampled by the Serenitatis impace (not necessarily the deepest crust) was basaltic in composition, including KREEP and gabbroic rocks like sodic ferrogabbro, and lacking abundant olivine-rich material. These were overlain by Mg-suite rocks of varied types, including norites and troctolites that supplied most of the olivine mineral fragments. Granulities, which are metamorphosed and more feldspathic breccias, were abundant near the surface. Remote sensing indicates that the entire Serenitatis region lacks ferroan anorthosite, consistent with the results of our study.

  18. 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

  19. Zirconium and hafnium complexes containing N-alkyl substituted amine biphenolate ligands: coordination chemistry and living ring-opening polymerization catalysis.

    Science.gov (United States)

    Liang, Lan-Chang; Lin, Sheng-Ta; Chien, Chia-Cheng; Chen, Ming-Tsz

    2013-07-01

    The coordination chemistry of zirconium and hafnium complexes containing the tridentate amine biphenolate ligands [RN(CH2-2-O-3,5-C6H2(tBu)2)2](2-) ([R-ONO](2-); R = tBu (1a), iPr (1b), nPr (1c)) featuring distinct N-alkyl substituents is described. Alcoholysis of Zr(OiPr)4(HOiPr) or Hf(OiPr)4(HOiPr) with H2[1a] in diethyl ether solutions at -35 °C generates the corresponding five-coordinate [1a]M(OiPr)2 (M = Zr (2a), Hf (3a)) in high isolated yield. Similar reactions employing H2[1b] produce six-coordinate [1b]M(OiPr)2(HOiPr) (M = Zr (2b·HOiPr), Hf (3b·HOiPr)) as an isopropanol adduct. Repetitive trituration of 2b·HOiPr and 3b·HOiPr with diethyl ether gives five-coordinate 2b and 3b, respectively. Treatment of M(OiPr)4(HOiPr) with H2[1c] under similar conditions affords six-coordinate [1c]M(OiPr)2(HOiPr) (M = Zr (2c·HOiPr), Hf (3c·HOiPr)), subsequent recrystallization of which from acetonitrile-diethyl ether solutions leads to acetonitrile adducts 2c·MeCN and 3c·MeCN. Reactivity studies of these zirconium and hafnium complexes revealed that they are all active catalysts for ring-opening polymerization of ε-caprolactone. Among them, the N-isopropyl derived complexes are most reactive. Polymerizations catalyzed by 2b, 3b and 3c·MeCN were proved to be living. The X-ray structures of 2a·HOiPr, 2a·MeCN, 2c·HOiPr, 2c·MeCN, and 3c·MeCN are presented.

  20. 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...

  1. Organic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-08-15

    This book with sixteen chapter explains organic chemistry on linkage isomerism such as alkane, cycloalkane, alkene, aromatic compounds, stereo selective isomerization, aromatic compounds, stereo selective isomerization, organic compounds, stereo selective isomerization, organic halogen compound, alcohol, ether, aldehyde and ketone, carboxylic acid, dicarboxylic acid, fat and detergent, amino, carbohydrate, amino acid and protein, nucleotide and nucleic acid and spectroscopy, a polymer and medical chemistry. Each chapter has introduction structure and characteristic and using of organic chemistry.

  2. 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 ...

  3. 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 ...

  4. 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.

  5. 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…

  6. 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.

  7. Third working meeting on radiation interaction. 1

    International Nuclear Information System (INIS)

    The following topics have been discussed during the meeting: elementary processes in radiation chemistry and physics (theory, inorganic and organic systems); applied radiation chemistry and radiation processing; techniques, methods and instrumentation used in radiation chemistry and radiation processing; and irradiation of food, agricultural products, pharmaceutical products, domestic and industrial wastes. 52 papers are included in part 1

  8. Third working meeting on radiation interaction. 2

    International Nuclear Information System (INIS)

    The following topics have been discussed during the meeting: elementary processes in radiation chemistry and physics (theory, inorganic and organic systems); applied radiation chemistry and radiation processing; techniques, methods and instrumentation used in radiation chemistry and radiation processing; and irradiation of food, agricultural products, pharmaceutical products, domestic and industrial wastes. 55 papers are included in part 2

  9. 8th 'Tihany' Symposium on Radiation Chemistry

    International Nuclear Information System (INIS)

    Several aspects of radiation chemistry and radiation effects on various substances have been treated at the meeting, short communications of papers are presented in this publication. All items within the scope of INIS database were indexed individually

  10. 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,

  11. 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

  12. 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

  13. 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

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. Studies on coordination chemistry and bioactivity of metal complexes of some nitrogen-sulfur donor ligands: Section A: hydraziniumdithiocarbazate and its complexes. Section B: complexes of Ni2+ and Cu2+ ions with s-picolyldithiocarbazate

    International Nuclear Information System (INIS)

    Two new nitrogen - sulphur donor ligands, hydraziniumdithiocarbazate(HzDTC) and S-picolyldithiocarbazate(SPDTC), along with three novel Schiff bases were prepared. Complexes of some of HzDTC with nickel(II), zinc(II), and those of SPDTC with nickel(II) and copper(II) were prepared and characterized by a variety of physico- chemical techniques. The ligand, HzDTC, was a potential bidentate and uninegatively charged providing terminal amino and thiolate bindings with the metal ions, while SPDTC coordinates via the pyridine nitrogen and the thiolate anion. All of the compounds were tested against four pathogenic bacteria and fungi. HzDTC was found to be very effective antimicrobial than its complexes. The complexes of SPDTC and the Schiff bases of HzDTC were more antifungal. None of the compounds were effective anti- cancer agents except for [Ni(HzDTCA)Cl.H2O], which was moderately active against CEM- SS (Human cell T- lymphoblastic) leukemic cells. (author)

  19. Why Society is a Complex Matter Meeting Twenty-first Century Challenges with a New Kind of Science

    CERN Document Server

    Ball, Philip

    2012-01-01

    Society is complicated. But this book argues that this does not place it beyond the reach of a science that can help to explain and perhaps even to predict social behaviour. As a system made up of many interacting agents – people, groups, institutions and governments, as well as physical and technological structures such as roads and computer networks – society can be regarded as a complex system. In recent years, scientists have made great progress in understanding how such complex systems operate, ranging from animal populations to earthquakes and weather. These systems show behaviours that cannot be predicted or intuited by focusing on the individual components, but which emerge spontaneously as a consequence of their interactions: they are said to be ‘self-organized’. Attempts to direct or manage such emergent properties generally reveal that ‘top-down’ approaches, which try to dictate a particular outcome, are ineffectual, and that what is needed instead is a ‘bottom-up’ approach that aim...

  20. 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

  1. Meeting the needs of children with medical complexity using a telehealth advanced practice registered nurse care coordination model.

    Science.gov (United States)

    Cady, Rhonda G; Erickson, Mary; Lunos, Scott; Finkelstein, Stanley M; Looman, Wendy; Celebreeze, Margaret; Garwick, Ann

    2015-07-01

    Effective care coordination is a key quality and safety strategy for populations with chronic conditions, including children with medical complexity (CMC). However, gaps remain in parent report of the need for care coordination help and receipt of care coordination help. New models must close this gap while maintaining family-centered focus. A three-armed randomized controlled trial conducted in an established medical home utilized an advanced practice registered nurse intervention based on Presler's model of clinic-based care coordination. The model supported families of CMC across settings using telephone only or telephone and video telehealth care coordination. Effectiveness was evaluated from many perspectives and this paper reports on a subset of outcomes that includes family-centered care (FCC), need for care coordination help and adequacy of care coordination help received. FCC at baseline and end of study showed no significant difference between groups. Median FCC scores of 18.0-20.0 across all groups indicated high FCC within the medical home. No significant differences were found in the need for care coordination help within or between groups and over time. No significant difference was found in the adequacy of help received between groups at baseline. However, this indicator increased significantly over time for both intervention groups. These findings suggest that in an established medical home with high levels of FCC, families of CMC have unmet needs for care coordination help that are addressed by the APRN telehealth care coordination model.

  2. 42 CFR 493.1210 - Condition: Routine chemistry.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Routine chemistry. 493.1210 Section 493....1210 Condition: Routine chemistry. If the laboratory provides services in the subspecialty of Routine chemistry, the laboratory must meet the requirements specified in §§ 493.1230 through 493.1256, §...

  3. 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.

  4. Dynamics and chemistry of Venus' large and complex cloud system : a science case for an in-situ long-term chemical laboratory

    Science.gov (United States)

    Widemann, Thomas; Määttänen, Anni; Wilquet, Valérie; McGouldrick, Kevin; Jessup, Kandis Lea; Wilson, Colin; Limaye, Sanjay; EuroVenus Consortium, the

    2014-05-01

    combine through meso-scale convection. In situ sampling of these aerosols represents a key measurement for constraining their properties, and identifying their role in the sulfurohydrological cycle by means of microphysical models of steadily increasing complexity. A probe/lander making a single descent will lack the spatial, temporal and local time coverage to address the coupling of compositional variations with radiative and dynamical properties of the atmosphere at cloud level, requiring a long duration flight. Establishing a long-term chemical laboratory in the cloud layer which would measure the detailed composition of both gas and liquid phases, and their latitudinal, diurnal and vertical variability using a combination of mass spectrometry, gas chromatography, tunable laser transmission spectrometry, and polar nephelometry would significantly address all of these objectives. It would allow the determination of the size distribution, shape, and real and imaginary refractive indices of the cloud particles, and the measurement of intensity and polarization phase functions. Our target species would include those known to be associated with cloud formation (e.g. H2SO4, SO3, SO2, H2O), as well as species important in stratospheric chemistry (e.g. CO, ClCOx, Ox, HCl, HF) and surface-atmosphere buffering (e.g. CO, OCS, SOx, Ox, H2S).

  5. Brittle-ductile deformation effects on zircon crystal-chemistry and U-Pb ages: an example from the Finero Mafic Complex (Ivrea-Verbano Zone, western Alps)

    Science.gov (United States)

    Langone, Antonio; José Alberto, Padrón-Navarta; Zanetti, Alberto; Mazzucchelli, Maurizio; Tiepolo, Massimo; Giovanardi, Tommaso; Bonazzi, Mattia

    2016-04-01

    A detailed structural, geochemical and geochronological survey was performed on zircon grains from a leucocratic dioritic dyke discordantly intruded within meta-diorites/gabbros forming the External Gabbro unit of the Finero Mafic Complex. This latter is nowadays exposed as part of a near complete crustal section spanning from mantle rocks to upper crustal metasediments (Val Cannobina, Ivrea-Verbano Zone, Italy). The leucocratic dyke consists mainly of plagioclase (An18‑24Ab79‑82Or0.3‑0.7) with subordinate amounts of biotite, spinel, zircon and corundum. Both the leucocratic dyke and the surrounding meta-diorites show evidence of ductile deformation occurred under amphibolite-facies conditions. Zircon grains (up to 2 mm in length) occur mainly as euhedral grains surrounded by fine grained plagioclase-dominated matrix and pressure shadows, typically filled by oxides. Fractures and cracks within zircon are common and can be associated with grain displacement or they can be filled by secondary minerals (oxides and chlorite). Cathodoluminescence (CL) images show that zircon grains have internal features typical of magmatic growth, but with local disturbances. However EBSD maps on two selected zircon grains revealed a profuse mosaic texture resulting in an internal misorientation of ca. 10o. The majority of the domains of the mosaic texture are related to parting and fractures, but some domains show no clear relation with brittle features. Rotation angles related to the mosaic texture are not crystallographically controlled. In addition, one of the analysed zircons shows clear evidence of plastic deformation at one of its corners due to indentation. Plastic deformation results in gradual misorientations of up to 12o, which are crystallographically controlled. Trace elements and U-Pb analyses were carried out by LA-ICP-MS directly on petrographic thin sections and designed to cover the entire exposed surface of selected grains. Such investigations revealed a strong

  6. 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

  7. 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.

  8. 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

  9. Industrial chemistry and chemoecology are linked together to realize a modern and sustainable chemistry

    OpenAIRE

    Saling Peter

    2007-01-01

    Abstract Meeting society's needs without damaging the environment requires new ways of thinking. The link of industrial chemistry and chemoecology will be one of the key factors of sustainable development within the chemicals industry.

  10. Industrial chemistry and chemoecology are linked together to realize a modern and sustainable chemistry

    Directory of Open Access Journals (Sweden)

    Saling Peter

    2007-03-01

    Full Text Available Abstract Meeting society's needs without damaging the environment requires new ways of thinking. The link of industrial chemistry and chemoecology will be one of the key factors of sustainable development within the chemicals industry.

  11. A computer model for one-dimensional mass and energy transport in and around chemically reacting particles, including complex gas-phase chemistry, multicomponent molecular diffusion, surface evaporation, and heterogeneous reaction

    Science.gov (United States)

    Cho, S. Y.; Yetter, R. A.; Dryer, F. L.

    1992-01-01

    Various chemically reacting flow problems highlighting chemical and physical fundamentals rather than flow geometry are presently investigated by means of a comprehensive mathematical model that incorporates multicomponent molecular diffusion, complex chemistry, and heterogeneous processes, in the interest of obtaining sensitivity-related information. The sensitivity equations were decoupled from those of the model, and then integrated one time-step behind the integration of the model equations, and analytical Jacobian matrices were applied to improve the accuracy of sensitivity coefficients that are calculated together with model solutions.

  12. 49. Meeting of the Chemical Societies: Proceedings of the contributions. Vol. 2

    International Nuclear Information System (INIS)

    The publication has been set up as a abstracts of the meeting dealing with chemical problems. The book (Vol. 2) consists of the sections: (C) Physical chemistry; (D) History of the chemistry; (E) Food chemistry and technology; (D) Environmental chemistry; (E) Nuclear chemistry and radioecology; (H) Synthetic polymers

  13. Quantum chemistry and relativity: exploring the physical and chemical properties of the complexes of heavy elements; Chimie quantique et relativite. Exploration des proprietes physiques et chimiques des complexes d'atomes lourds

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, V. [Munich Univ., Institute for Theoretical Chemistry, Technical (Germany)

    2003-01-01

    Molecular and nano-molecular systems containing rare earth and actinides elements have extraordinary chemical and physical properties. Computer simulations using quantum chemistry methods can play an important role in many investigative procedures and provide help in understanding the microscopic nature of the interactions governing these macroscopic properties. The recent theoretical efforts have been devoted to the development of accurate and efficient methods that take into account all important interactions influencing the electronic structures, such as electron correlation and relativity. In particular, we illustrate the importance of relativity on chemical and spectroscopic properties. We will then focus on the modelling aspects of solution chemistry. (author)

  14. 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

  15. 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.

  16. 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.

  17. Marcoule Institute for Separation Chemistry - 2009-2012 Scientific report

    International Nuclear Information System (INIS)

    The mixed research unit 'Institute for Separation Chemistry' was created jointly by CEA, CNRS, University of Montpellier and Ecole Nationale Superieure de Chimie de Montpellier in March 2007. The building has been inaugurated in June 2009, with laboratories opened in the fall 2009 and has obtained authorisation to start experiments including a few grams of depleted uranium and natural thorium in January 2010. Last take-off was the theory group, who started in October 2009. Resources in Uranium are scarce, if only the 235 isotope is used and wastes related to nuclear energy production are potentially dangerous. The use of fast neutrons allows to multiply existing resources in national independence, but will be based on new separation processes, that can be modelled using predictive theory. Understanding and optimizing separation in the nuclear fuel cycle is the central aim of the 'Institute for Separation Chemistry' (ICSM). Enlarging this central goal to the needs for chemistry of recycling, for instance, strategic metals crucial for alternative energy, is the natural extension surfaces of needs and development of science, with a strong link for technology and implementation. This report gives an overview of the work published and submitted by ICSM since January 2009. The nine active research teams still work in the direction of the scientific open questions as defined and published by the French academy in 2007. The report is organized by scientific topics: each of the nine active research groups gathers a community of researchers and engineers from different expertises, who publish in various domains in the corresponding journals, and who participate at different international meetings. The research teams are organized as follows: 1 - Chemistry and Physical-chemistry of the Actinides; 2 - Ions at Active Interfaces; 3 - Ionic Separation from self-assembled Molecular systems; 4 - Sono-chemistry in Complex Fluids; 5 - Nano-materials for Energy and Recycling processes

  18. 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...

  19. 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...

  20. Atom transfer as a preparative tool in coordination chemistry. Synthesis and characterization of Cr(V) nitrido complexes of bidentate ligands

    DEFF Research Database (Denmark)

    Birk, Torben; Bendix, Jesper

    2003-01-01

    a mixture of CrV nitrido species with only labile auxiliary ligands. From this solution CrV nitrido complexes with bidentate monoanionic ligands can be obtained in high yields. Five coordinate complexes of 8-hydroxoquinolinate (quin), 1,3-diphenylpropane-1,3-dionate (dbm), and pyrrolidinedithiocarbamate...... = 11.8267(12) Å, ß = 106.528(7)°, V = 1441.7(2) Å3, Z = 4. Complexes 2 and 3 represent new coordination environments for first row transition metal nitrido complexes. The d-orbital energy splitting in these systems with relatively weak equatorial donors differs significantly from the pattern in vanadyl...

  1. 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.

  2. In-situ Evaluation of Soil Organic Molecules: Functional Group Chemistry Aggregate Structures, Metal & Surface Complexation Using Soft X-Ray

    Energy Technology Data Exchange (ETDEWEB)

    Myneni, Satish, C

    2008-11-30

    Organic molecules are common in all Earth surface environments, and their composition and chemistry play an important role in a variety of biogeochemical reactions, such as mineral weathering, nutrient cycling and the solubility and transport of contaminants. However, most of what we know about the chemistry of these molecules comes from spectroscopy and microscopy studies of organic molecules extracted from different natural systems using either inorganic or organic solvents. Although all these methods gave us clues about the composition of these molecules, their composition and structure change with the extraction and the type of ex-situ analysis, their true behavior is less well understood. The goal of this project is to develop synchrotron instrumentation for studying natural organics, and to apply these recently developed synchrotron X-ray spectroscopy and microscopy techniques for understanding the: (1) functional group composition of naturally occurring organic molecules; (2) macromolecular structures of organic molecules; and (3) the nature of interactions of organic molecules with mineral surfaces in different environmental conditions.

  3. Structure and intermolecular vibrations of 7-azaindole-water 2:1 complex in a supersonic jet expansion: Laser-induced fluorescence spectroscopy and quantum chemistry calculation

    Indian Academy of Sciences (India)

    Montu K Hazra; Moitrayee Mukherjee; V Ramanathan; Tapas Chakraborty

    2012-01-01

    Laser-induced fluorescence spectra of a 2:1 complex between 7-azaindole and water, known as `non-reactive dimer’ of the molecule, have been measured in a supersonic jet expansion. The dispersed fluorescence spectrum of the electronic origin band of the complex shows a very large number of low-frequency vibrational features corresponding to different intermolecular modes of the complex in the ground electronic state. Geometries of several possible isomeric structures of the complex and their vibrational frequencies at harmonic approximation were calculated by electronic structure theory method at MP2/6-31G∗∗ level. An excellent agreement is observed between the measured and calculated intermolecular vibrational mode frequencies for the energetically most favoured structure of the complex, where the water molecule is inserted within one of the two N$\\cdots$H-N hydrogen bonds of the 7AI dimer.

  4. 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.

  5. 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

  6. Oligocyclopentadienyl transition metal complexes

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  7. Novel mononuclear vanadium complexes having pentalene ligands η8-bonded to a single metal atom - a new type of coordination in organometallic chemistry

    International Nuclear Information System (INIS)

    The pronounced folding of the η8-coordinated pentalene ligand along the bond between the two bridgehead carbon atoms is the most prominent structural feature of the vanadium complex 2. This compound and further 18e complexes of this type are readily prepared by the reaction of vanadocene monohalides 1 or their derivatives with dilithium pentalenediide. Although these mononuclear complexes are air-sensitive, they are thermally so stable that they can be sublimed in high vacuum at 80-100 C without decomposition. (orig.)

  8. Novel mononuclear vanadium complexes having pentalene ligands {eta}{sup 8}-bonded to a single metal atom - a new type of coordination in organometallic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Jonas, K.; Gabor, B.; Mynott, R.; Angermund, K.; Heinemann, O.; Krueger, C. [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany)

    1997-09-01

    The pronounced folding of the {eta}{sup 8}-coordinated pentalene ligand along the bond between the two bridgehead carbon atoms is the most prominent structural feature of the vanadium complex 2. This compound and further 18e complexes of this type are readily prepared by the reaction of vanadocene monohalides 1 or their derivatives with dilithium pentalenediide. Although these mononuclear complexes are air-sensitive, they are thermally so stable that they can be sublimed in high vacuum at 80-100 C without decomposition. (orig.)

  9. Quantitative HPLC-ICP-MS analysis of antimony redox speciation in complex sample matrices: new insights into the Sb-chemistry causing poor chromatographic recoveries

    DEFF Research Database (Denmark)

    Hansen, Claus; Schmidt, Bjørn; Larsen, Erik Huusfeldt;

    2011-01-01

    In solution antimony exists either in the pentavalent or trivalent oxidation state. As Sb(III) is more toxic than Sb(V), it is important to be able to perform a quantitative speciation analysis of Sb’s oxidation state. The most commonly applied chromatographic methods used for this redox speciation...... analysis do, however, often show a low chromatographic Sb recovery when samples of environmental or biological origin are analysed. In this study we explored basal chemistry of antimony and found that formation of macromolecules, presumably oligomeric and polymeric Sb(V) species, is the primary cause...... of low chromatographic recoveries. A combination of HPLC-ICP-MS, AFFF-ICP-MS and spinfiltration was applied for analysis of model compounds and biological samples. Quantitative chromatographic Sb redox speciation analysis was possible by acidic hydrolysis of the antimony polymers prior to analysis...

  10. Mathematical methods for physical and analytical chemistry

    CERN Document Server

    Goodson, David Z

    2011-01-01

    Mathematical Methods for Physical and Analytical Chemistry presents mathematical and statistical methods to students of chemistry at the intermediate, post-calculus level. The content includes a review of general calculus; a review of numerical techniques often omitted from calculus courses, such as cubic splines and Newton's method; a detailed treatment of statistical methods for experimental data analysis; complex numbers; extrapolation; linear algebra; and differential equations. With numerous example problems and helpful anecdotes, this text gives chemistry students the mathematical

  11. 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

  12. Iridium(I) Compounds as Prospective Anticancer Agents: Solution Chemistry, Antiproliferative Profiles and Protein Interactions for a Series of Iridium(I) N-Heterocyclic Carbene Complexes.

    Science.gov (United States)

    Gothe, Yvonne; Marzo, Tiziano; Messori, Luigi; Metzler-Nolte, Nils

    2016-08-22

    A series of structurally related mono- and bis-NHC-iridium(I) (NHC: N-heterocyclic carbene) complexes have been investigated for their suitability as potential anticancer drugs. Their spectral behaviour in aqueous buffers under physiological-like conditions and their cytotoxicity against the cancer cell lines MCF-7 and HT-29 are reported. Notably, almost all complexes exhibit significant cytotoxic effects towards both cancer cell lines. In general, the cationic bis-carbene complexes show higher stability and greater anticancer activity than their neutral mono-carbene analogues with IC50 values in the high nanomolar range. Furthermore, to gain initial mechanistic insight, the interactions of these iridium(I)-NHC complexes with two model proteins, namely lysozyme and cytochrome c, were explored by HR-ESI-MS analyses. The different protein metalation patterns of the complexes can be roughly classified into two distinct groups. Those interactions give us a first idea about the possible mechanism of action of this class of compounds. Overall, our findings show that iridium(I)-NHC complexes represent very interesting candidates for further development as new metal-based anticancer drugs.

  13. A smart recipe of chemistry and management

    OpenAIRE

    Seeger, S

    2008-01-01

    The Bachelor and Master Program in Chemistry and Business Studies has been offered by the Chemical Institutes of the University of Zurich since 2004 to meet the growing demand for graduates with solid scientific and technical background but also management skills. The program has attracted a large number of students whilst not affecting the numbers in the chemistry program showing that young people are attracted who would not otherwise have chosen a science degree. Future planned development ...

  14. Dissociation of diglycolamide complexes of Ln3+ (Ln = La-Lu) and An3+ (An = Pu, Am, Cm): redox chemistry of 4f and 5f elements in the gas phase parallels solution behavior.

    Science.gov (United States)

    Gong, Yu; Tian, Guoxin; Rao, Linfeng; Gibson, John K

    2014-11-17

    Tripositive lanthanide and actinide ions, Ln(3+) (Ln = La-Lu) and An(3+) (An = Pu, Am, Cm), were transferred from solution to gas by electrospray ionization as Ln(L)3(3+) and An(L)3(3+) complexes, where L = tetramethyl-3-oxa-glutaramide (TMOGA). The fragmentation chemistry of the complexes was examined by collision-induced and electron transfer dissociation (CID and ETD). Protonated TMOGA, HL(+), and Ln(L)(L-H)(2+) are the major products upon CID of La(L)3(3+), Ce(L)3(3+), and Pr(L)3(3+), while Ln(L)2(3+) is increasingly pronounced beyond Pr. A C-Oether bond cleavage product appears upon CID of all Ln(L)3(3+); only for Eu(L)3(3+) is the divalent complex, Eu(L)2(2+), dominant. The CID patterns of Pu(L)3(3+), Am(L)3(3+), and Cm(L)3(3+) are similar to those of the Ln(L)3(3+) for the late Ln. A striking exception is the appearance of Pu(IV) products upon CID of Pu(L)3(3+), in accord with the relatively low Pu(IV)/Pu(III) reduction potential in solution. Minor divalent Ln(L)2(2+) and An(L)2(2+) were produced for all Ln and An; with the exception of Eu(L)2(2+) these complexes form adducts with O2, presumably producing superoxides in which the trivalent oxidation state is recovered. ETD of Ln(L)3(3+) and An(L)3(3+) reveals behavior which parallels that of the Ln(3+) and An(3+) ions in solution. A C-Oether bond cleavage product, in which the trivalent oxidation state is preserved, appeared for all complexes; charge reduction products, Ln(L)2(2+) and Ln(L)3(2+), appear only for Sm, Eu, and Yb, which have stable divalent oxidation states. Both CID and ETD reveal chemistry that reflects the condensed-phase redox behavior of the 4f and 5f elements.

  15. Systems chemistry: All in a spin

    Science.gov (United States)

    Clark, Lucy; Lightfoot, Philip

    2016-05-01

    A fundamental challenge in systems chemistry is to engineer the emergence of complex behaviour. The collective structures of metal cyanide chains have now been interpreted in the same manner as the myriad of magnetic phases displayed by frustrated spin systems, highlighting a symbiotic approach between systems chemistry and magnetism.

  16. Advanced radiation chemistry research: Current status

    International Nuclear Information System (INIS)

    Radiation chemistry is a branch of chemistry that studies chemical transformations in materials exposed to high-energy radiations. It is based on the use of ionizing radiation as the initiator or catalyst in chemical reactions. The most significant advantage of radiation chemistry lies in its ability to be used in the production and study of almost any reactive atomic and molecular species playing a part in chemical reaction, synthesis, industrial processes, or in biological systems. Over the the last few years a number of meetings have taken place, under the auspices of the IAEA, in order to evaluate recent developments in radiation chemistry as well as the trends indicated by the results obtained. Radiation chemists from different countries have participated at these meetings. The present publication, a companion to the previous publication - New Trends and Development in Radiation Chemistry, IAEA-TECDOC-527 (1989) - includes some of the important contributions presented at these meetings. It is hoped that it will provide a useful overview of current activities and of emerging trends in this field, thus promoting better understanding of potential contributions of radiation chemistry to other fields of knowledge as well as to practical applications in industry, medicine and agriculture. Refs, figs and tabs

  17. Solution chemistry of a water-soluble eta2-H2 ruthenium complex: evidence for coordinated H2 acting as a hydrogen bond donor.

    Science.gov (United States)

    Szymczak, Nathaniel K; Zakharov, Lev N; Tyler, David R

    2006-12-13

    The ability of an eta2-H2 ligand to participate in intermolecular hydrogen bonding in solution has long been an unresolved issue. Such species are proposed to be key intermediates in numerous important reactions such as the proton-transfer pathway of H2 production by hydrogenase enzymes. We present the synthesis of several new water-soluble ruthenium coordination complexes including an eta2-H2 complex that is surprisingly inert to substitution by water. The existence of dihydrogen hydrogen bonding (DHHB) was experimentally probed by monitoring the chemical shift of H-bonded Ru-(H2) complexes using NMR spectroscopy, by UV-visible spectroscopy, and by monitoring the rotational dynamics of a hydrogen-bonding probe molecule. The results provide strong evidence that coordinated H2 can indeed participate in intermolecular hydrogen bonding to bulk solvent and other H-bond acceptors. PMID:17147394

  18. Sustainable chemistry metrics.

    Science.gov (United States)

    Calvo-Flores, Francisco García

    2009-01-01

    Green chemistry has developed mathematical parameters to describe the sustainability of chemical reactions and processes, in order to quantify their environmental impact. These parameters are related to mass and energy magnitudes, and enable analyses and numerical diagnoses of chemical reactions. The environmental impact factor (E factor), atom economy, and reaction mass efficiency have been the most influential metrics, and they are interconnected by mathematical equations. The ecodesign concept must also be considered for complex industrial syntheses, as a part of the sustainability of manufacturing processes. The aim of this Concept article is to identify the main parameters for evaluating undesirable environmental consequences. PMID:19780101

  19. 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

  20. 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...

  1. Friendship chemistry: An examination of underlying factors☆

    Science.gov (United States)

    Campbell, Kelly; Holderness, Nicole; Riggs, Matt

    2015-01-01

    Interpersonal chemistry refers to a connection between two individuals that exists upon first meeting. The goal of the current study is to identify beliefs about the underlying components of friendship chemistry. Individuals respond to an online Friendship Chemistry Questionnaire containing items that are derived from interdependence theory and the friendship formation literature. Participants are randomly divided into two subsamples. A principal axis factor analysis with promax rotation is performed on subsample 1 and produces 5 factors: Reciprocal candor, mutual interest, personableness, similarity, and physical attraction. A confirmatory factor analysis is conducted using subsample 2 and provides support for the 5-factor model. Participants with agreeable, open, and conscientious personalities more commonly report experiencing friendship chemistry, as do those who are female, young, and European/white. Responses from participants who have never experienced chemistry are qualitatively analyzed. Limitations and directions for future research are discussed. PMID:26097283

  2. Sites of Chemistry in the Nineteenth Century

    OpenAIRE

    García Belmar, Antonio

    2014-01-01

    The three articles in this special issue of Ambix were among the twenty-one papers presented at the conference “Sites of Chemistry in the Nineteenth Century,” held in Valencia at the Institute for the History of Medicine and Science ‘López Piñero’ in July 2012. This meeting was the second of the series of conferences organised as part of the project Sites of Chemistry, 1600–2000, the aim of which was to investigate the wide and diverse range of physical spaces and places where chemistry has b...

  3. Martian Chlorine Chemistry: A Study of Perchlorate on the Martian Surface, Evidence of an Ongoing Formation Mechanism and Implications of a Complex Chlorine Cycle

    Science.gov (United States)

    Carrier, Brandi L.

    2015-10-01

    The research presented herein addresses the detection of perchlorate on Mars, evidence of perchlorate in Mars meteorite EETA 79001, determination of the perchlorate parent salts at the Phoenix landing site, and the ongoing formation of perchlorate from chloride minerals as well as from other oxychlorine species. The detection of perchlorate in three samples by the Phoenix Wet Chemistry Laboratory and the implication of these results are discussed. The further detection of perchlorate in Mars meteorite EETA 79001 by ion chromatography and the determination of the parent salts of the perchlorate detected at the Phoenix landing site by electrochemical analyses and ion chromatography are detailed and the implications of the identity of the parent salts are discussed. The possible formation pathways for martian perchlorate are then explored and a possible mechanism for ongoing perchlorate formation on the martian surface is detailed. Perchlorate is shown to be formed upon exposure of chloride minerals, as well as of chlorite and chlorate salts, to current Mars relevant conditions including temperature, pressure, ultraviolet radiation and atmospheric composition. The implications of this ongoing perchlorate formation for the survival and detection of organics, the oxidizing nature of the soil, formation of liquid brines and recurring slope lineae are discussed. Further preliminary experiments have been conducted to investigate the effects of perchlorate formation on the survival and degradation of organic compounds.

  4. 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)…

  5. 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).

  6. Developments in the Coordination Chemistry of Europium(II)

    OpenAIRE

    Garcia, Joel; Allen, Matthew J.

    2012-01-01

    Recent advances in the coordination chemistry of Eu2+ are reviewed. Common synthetic routes for generating discrete Eu2+-containing complexes reported since 2000 are summarized, followed by a description of the reactivity of these complexes and their applications in reduction chemistry, polymerization, luminescence, and as contrast agents for magnetic resonance imaging. Rapid development of the coordination chemistry of Eu2+ has led to an upsurge in the utilization of Eu2+-containing complexe...

  7. 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 ...

  8. Organic chemistry on solid surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Zhen; Zaera, Francisco [Department of Chemistry, University of California, Riverside, CA 92521 (United States)

    2006-07-15

    Chemistry on solid surfaces is central to many areas of practical interest such as heterogeneous catalysis, tribology, electrochemistry, and materials processing. With the development of many surface-sensitive analytical techniques in the past decades, great advances have been possible in our understanding of such surface chemistry at the molecular level. Earlier studies with model systems, single crystals in particular, have provided rich information about the adsorption and reaction kinetics of simple inorganic molecules. More recently, the same approach has been expanded to the study of the surface chemistry of relatively complex organic molecules, in large measure in connection with the selective synthesis of fine chemicals and pharmaceuticals. In this report, the chemical reactions of organic molecules and fragments on solid surfaces, mainly on single crystals of metals but also on crystals of metal oxides, carbides, nitrides, phosphides, sulfides and semiconductors as well as on more complex models such as bimetallics, alloys, and supported particles, are reviewed. A scheme borrowed from the organometallic and organic chemistry literature is followed in which key examples of representative reactions are cited first, and general reactivity trends in terms of both the reactants and the nature of the surface are then identified to highlight important mechanistic details. An attempt has been made to emphasize recent advances, but key earlier examples are cited as needed. Finally, correlations between surface and organometallic and organic chemistry, the relevance of surface reactions to applied catalysis and materials functionalization, and some promising future directions in this area are briefly discussed. (author)

  9. On the formulation of species reaction rates in the context of multi-species CFD codes using complex chemistry tabulation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Michel, Jean-Baptiste; Colin, Olivier; Angelberger, Christian [IFP, 1 et 4 Avenue de Bois Preau, F-92500 Rueil Malmaison (France)

    2010-04-15

    In the standard implementation of tabulated combustion models of the FPI or FGM type, the mean species mass fractions are read from look-up tables as functions of a progress variable, mixture fraction and their variances. In multi-species CFD codes however, the mean thermodynamic properties are deduced from the local mean species mass fractions. The unclosed mean source terms appearing in the latter's transport equations must then be given by the chemistry look-up tables. Two possible formulations for this mean source terms are discussed and compared in the present paper. In the reaction rate (RR) formulation, all mean reaction rates are directly read from a look-up table. In the mass fraction (MF) formulation, only the reaction rate for the progress variable is stored, and mean species source terms are constructed to relax the mean mass fractions towards the value stored in the look-up table. After a detailed description of in particular the MF formulation, simple a priori tests of auto-igniting reactors without convection and diffusion are used to illustrate and discuss the differences between the two formulations. Both formulations are then applied to a RANS simulation of the Cabra et al. burner in the context of a PCM-FPI and of an ADF-PCM model. The reported findings confirm the conclusions from the simple tests, highlighting the definitive advantages of the MF formulation. It ensures an accurate reproduction of auto-ignition delays, species evolutions and equilibriums, at the condition that the relaxation parameter is of the order of a characteristic chemical time. Finally, it is shown that the relaxation's effect is only a second order correction. (author)

  10. New chemistry from an old reagent: mono- and dinuclear macrocyclic uranium(III) complexes from [U(BH4)3(THF)2].

    Science.gov (United States)

    Arnold, Polly L; Stevens, Charlotte J; Farnaby, Joy H; Gardiner, Michael G; Nichol, Gary S; Love, Jason B

    2014-07-23

    A new robust and high-yielding synthesis of the valuable U(III) synthon [U(BH4)3(THF)2] is reported. Reactivity in ligand exchange reactions is found to contrast significantly to that of uranium triiodide. This is exemplified by the synthesis and characterization of azamacrocyclic U(III) complexes, including mononuclear [U(BH4)(L)] and dinuclear [Li(THF)4][{U(BH4)}2(μ-BH4)(L(Me))] and [Na(THF)4][{U(BH4)}2(μ-BH4)(L(A))(THF)2]. The structures of all complexes have been determined by single-crystal X-ray diffraction and display two new U(III)2(BH4)3 motifs.

  11. Dibutyltin(IV) complexes containing arylazobenzoate ligands: chemistry, in vitro cytotoxic effects on human tumor cell lines and mode of interaction with some enzymes.

    Science.gov (United States)

    Basu Baul, Tushar S; Paul, Anup; Pellerito, Lorenzo; Scopelliti, Michelangelo; Singh, Palwinder; Verma, Pooja; Duthie, Andrew; de Vos, Dick; Tiekink, Edward R T

    2011-04-01

    Dibutyltin(IV) complexes of composition Bu₂Sn(LH)₂, where LH is a carboxylate residue derived from 2-[(E)-(5-tert-butyl-2-hydroxyphenyl)diazenyl]benzoate (L¹H) with water molecule (1), 4-[(E)-(5-tert-butyl-2-hydroxyphenyl)diazenyl]benzoate (L²H) (2) and 4-[(E)-(4-hydroxy-5-methylphenyl)diazenyl]benzoate (L³H) (3), were synthesized and characterized by spectroscopic (¹H, ¹³C and ¹¹⁹Sn NMR, IR, ¹¹⁹Sn Mössbauer) techniques. A full characterization was accomplished from the crystal structure of complex 1. The molecular structures and geometries of the complexes (1a i.e. 1 without water molecule and 3) were fully optimized using the quantum mechanical method (PM6). Complexes 1 and 3 were found to exhibit stronger cytotoxic activity in vitro across a panel of human tumor cell lines viz., A498, EVSA-T, H226, IGROV, M19 MEL, MCF-7 and WIDR. Compound 3 is found to be four times superior for the A498, EVSA-T and MCF-7 cell lines than CCDP (cisplatin), and four, eight and sixteen times superior for the A498, H226 and MCF-7 cell lines, respectively, compared to ETO (etoposide). The mechanistic role of cytotoxic activity of test compounds is discussed in relation to the theoretical results of docking studies with some key enzymes such as ribonucleotide reductase, thymidylate synthase, thymidylate phosphorylase and topoisomerase II associated with the propagation of cancer. PMID:20012338

  12. Almanac of the contributions of the 49. meeting of the chemical societies. Selected papers from Vol. 1,2,3

    International Nuclear Information System (INIS)

    The publication has been set up as a abstracts of the meeting dealing with chemical problems. The book (Vol. 1) consists of the sections: (A) Analytical chemistry; (B) Inorganic chemistry. The book (Vol. 2) consists of the sections: (C) Physical chemistry; (D) History of the chemistry; (E) Food chemistry and technology; (D) Environmental chemistry; (E) Nuclear chemistry and radioecology; (H) Synthetic polymers. The book (Vol. 3) consists of the sections: (I) Fibres, Textile and foil materials; (J) Wood, pulp, paper; (K) Organic Chemistry; (L) Bio-organic chemistry; (M) Didactic of the chemistry

  13. Coordination chemistry of two heavy metals: I, Ligand preferences in lead(II) complexation, toward the development of therapeutic agents for lead poisoning: II, Plutonium solubility and speciation relevant to the environment

    International Nuclear Information System (INIS)

    The coordination chemistry and solution behavior of the toxic ions lead(II) and plutonium(IV, V, VI) have been investigated. The ligand pKas and ligand-lead(II) stability constants of one hydroxamic acid and four thiohydroaxamic acids were determined. Solution thermodynamic results indicate that thiohydroxamic acids are more acidic and slightly better lead chelators than hydroxamates, e.g., N-methylthioaceto-hydroxamic acid, pKa = 5.94, logβ120 = 10.92; acetohydroxamic acid, pKa = 9.34, logβl20 = 9.52. The syntheses of lead complexes of two bulky hydroxamate ligands are presented. The X-ray crystal structures show the lead hydroxamates are di-bridged dimers with irregular five-coordinate geometry about the metal atom and a stereochemically active lone pair of electrons. Molecular orbital calculations of a lead hydroxamate and a highly symmetric pseudo octahedral lead complex were performed. The thermodynamic stability of plutonium(IV) complexes of the siderophore, desferrioxamine B (DFO), and two octadentate derivatives of DFO were investigated using competition spectrophotometric titrations. The stability constant measured for the plutonium(IV) complex of DFO-methylterephthalamide is logβ110 = 41.7. The solubility limited speciation of 242Pu as a function of time in near neutral carbonate solution was measured. Individual solutions of plutonium in a single oxidation state were added to individual solutions at pH = 6.0, T = 30.0, 1.93 mM dissolved carbonate, and sampled over intervals up to 150 days. Plutonium solubility was measured, and speciation was investigated using laser photoacoustic spectroscopy and chemical methods

  14. Coordination chemistry of two heavy metals: I, Ligand preferences in lead(II) complexation, toward the development of therapeutic agents for lead poisoning: II, Plutonium solubility and speciation relevant to the environment

    Energy Technology Data Exchange (ETDEWEB)

    Neu, M.P. [Lawrence Berkeley Lab., CA (United States)

    1993-11-01

    The coordination chemistry and solution behavior of the toxic ions lead(II) and plutonium(IV, V, VI) have been investigated. The ligand pK{sub a}s and ligand-lead(II) stability constants of one hydroxamic acid and four thiohydroaxamic acids were determined. Solution thermodynamic results indicate that thiohydroxamic acids are more acidic and slightly better lead chelators than hydroxamates, e.g., N-methylthioaceto-hydroxamic acid, pK{sub a} = 5.94, log{beta}{sub 120} = 10.92; acetohydroxamic acid, pK{sub a} = 9.34, log{beta}{sub l20} = 9.52. The syntheses of lead complexes of two bulky hydroxamate ligands are presented. The X-ray crystal structures show the lead hydroxamates are di-bridged dimers with irregular five-coordinate geometry about the metal atom and a stereochemically active lone pair of electrons. Molecular orbital calculations of a lead hydroxamate and a highly symmetric pseudo octahedral lead complex were performed. The thermodynamic stability of plutonium(IV) complexes of the siderophore, desferrioxamine B (DFO), and two octadentate derivatives of DFO were investigated using competition spectrophotometric titrations. The stability constant measured for the plutonium(IV) complex of DFO-methylterephthalamide is log{beta}{sub 110} = 41.7. The solubility limited speciation of {sup 242}Pu as a function of time in near neutral carbonate solution was measured. Individual solutions of plutonium in a single oxidation state were added to individual solutions at pH = 6.0, T = 30.0, 1.93 mM dissolved carbonate, and sampled over intervals up to 150 days. Plutonium solubility was measured, and speciation was investigated using laser photoacoustic spectroscopy and chemical methods.

  15. Crossword Puzzles for Chemistry Education: Learning Goals beyond Vocabulary

    Science.gov (United States)

    Yuriev, Elizabeth; Capuano, Ben; Short, Jennifer L.

    2016-01-01

    Chemistry is a technical scientific discipline strongly underpinned by its own complex and diverse language. To be successful in the problem-solving aspects of chemistry, students must master the language of chemistry, and in particular, the definition of terms and concepts. To assist students in this challenging task, a variety of instructional…

  16. Petrography and mineral chemistry of carbonatites and mica-rich rocks from the Araxá complex (Alto Paranaíba Province, Brazil

    Directory of Open Access Journals (Sweden)

    TRAVERSA GIANBOSCO

    2001-01-01

    Full Text Available The Araxá complex (16 km² comprises carbonatites forming a central core and a complex network of concentric and radial dykes as well as small veins; additionally, it includes mica-rich rocks, phoscorites and lamprophyres. Fenites also occur and are represented by Proterozoic quartzites and schists of the Araxá Group. The petrographic study of 130 borehole samples indicates that the complex is basically made up by two rock-types, carbonatites and mica-rich rocks, and subordinately by a third unit of hybrid composition. Carbonatites range chemically in composition, the most abundant type being magnesiocarbonatites. Dolomite and calcite correspond to the chief constituents, but other carbonate phases, including the Ce-group RE minerals, are also recognized. Phosphates and oxides are widespread accessories whereas silicate minerals consist of olivine, clinopyroxene, mica and amphibole. Mica-rich rocks are represented by abundant glimmeritic rocks and scarce cumulitic phlogopite-, olivine- and diopside-bearing pyroxenites. Hybrid rocks mainly contain phlogopite and tetraferriphlogopite as cumulus and intercumulus phases, respectively; carbonate minerals may also be found. Chemical data indicate that the carbonatites are strongly enriched in REE and have lower contents of Nb, Zr, V, Cr, Ni and Rb compared to the mica-rich rocks. The higher K, Nb and Zr contents of the latter rocks are believed to be related to metasomatic processes (glimmeritization of the pyroxenites. Similar REE patterns for carbonatites and mica-rich rocks seem to suggest that they are related to a single parental magma, possibly of ijolitic composition. Steep LREE/HREE fractionation and high sigmaREE content of some carbonatite samples would be explained by hydrothermal and supergenic processes.

  17. Quantum chemistry study of uranium(VI), neptunium(V), and plutonium(IV,VI) complexes with preorganized tetradentate phenanthrolineamide ligands.

    Science.gov (United States)

    Xiao, Cheng-Liang; Wu, Qun-Yan; Wang, Cong-Zhi; Zhao, Yu-Liang; Chai, Zhi-Fang; Shi, Wei-Qun

    2014-10-20

    The preorganized tetradentate 2,9-diamido-1,10-phenanthroline ligand with hard-soft donors combined in the same molecule has been found to possess high selectivity toward actinides in an acidic aqueous solution. In this work, density functional theory (DFT) coupled with the quasi-relativistic small-core pseudopotential method was used to investigate the structures, bonding nature, and thermodynamic behavior of uranium(VI), neptunium(V), and plutonium(IV,VI) with phenanthrolineamides. Theoretical optimization shows that Et-Tol-DAPhen and Et-Et-DAPhen ligands are both coordinated with actinides in a tetradentate chelating mode through two N donors of the phenanthroline moiety and two O donors of the amide moieties. It is found that [AnO2L(NO3)](n+) (An = U(VI), Np(V), Pu(VI); n = 0, 1) and PuL(NO3)4 are the main 1:1 complexes. With respect to 1:2 complexes, the reaction [Pu(H2O)9](4+)(aq) + 2L(org) + 2NO3(-)(aq) → [PuL2(NO3)2](2+)(org) + 9H2O(aq) might be another probable extraction mechanism for Pu(IV). From the viewpoint of energy, the phenanthrolineamides extract actinides in the order of Pu(IV) > U(VI) > Pu(VI) > Np(V), which agrees well with the experimental results. Additionally, all of the thermodynamic reactions are more energetically favorable for the Et-Tol-DAPhen ligand than the Et-Et-DAPhen ligand, indicating that substitution of one ethyl group with one tolyl group can enhance the complexation abilities toward actinide cations (anomalous aryl strengthening).

  18. Air oxygenation chemistry of 4-TBC catalyzed by chloro bridged dinuclear copper(II) complexes of pyrazole based tridentate ligands: synthesis, structure, magnetic and computational studies.

    Science.gov (United States)

    Banerjee, Ishita; Samanta, Pabitra Narayan; Das, Kalyan Kumar; Ababei, Rodica; Kalisz, Marguerite; Girard, Adrien; Mathonière, Corine; Nethaji, M; Clérac, Rodolphe; Ali, Mahammad

    2013-02-01

    Four dinuclear bis(μ-Cl) bridged copper(II) complexes, [Cu(2)(μ-Cl)(2)(L(X))(2)](ClO(4))(2) (L(X) = N,N-bis[(3,5-dimethylpyrazole-1-yl)-methyl]benzylamine with X = H(1), OMe(2), Me(3) and Cl(4)), have been synthesized and characterized by the single crystal X-ray diffraction method. In these complexes, each copper(II) center is penta-coordinated with square-pyramidal geometry. In addition to the tridentate L(X) ligand, a chloride ion occupies the last position of the square plane. This chloride ion is also bonded to the neighboring Cu(II) site in its axial position forming an SP-I dinuclear Cu(II) unit that exhibits small intramolecular ferromagnetic interactions and supported by DFT calculations. The complexes 1-3 exhibit methylmonooxygenase (pMMO) behaviour and oxidise 4-tert-butylcatechol (4-TBCH(2)) with molecular oxygen in MeOH or MeCN to 4-tert-butyl-benzoquinone (4-TBQ), 5-methoxy-4-tert-butyl-benzoquinone (5-MeO-4-TBQ) as the major products along with 6,6'-Bu(t)-biphenyl-3,4,3',4'-tetraol and others as minor products. These are further confirmed by ESI- and FAB-mass analyses. A tentative catalytic cycle has been framed based on the mass spectral analysis of the products and DFT calculations on individual intermediates that are energetically feasible. PMID:23172025

  19. Managing Meetings

    Science.gov (United States)

    Hay, Susan

    2010-01-01

    Meetings are a means of giving people a chance to contribute. Meetings are also the nursery where the people's skills of listening, speaking, and building good working relationships are honed. They are where people practice being courteously challenging and confident, and they are where people are fascinated and fascinating. Meetings are where…

  20. Theoretical chemistry advances and perspectives

    CERN Document Server

    Eyring, Henry

    1980-01-01

    Theoretical Chemistry: Advances and Perspectives, Volume 5 covers articles concerning all aspects of theoretical chemistry. The book discusses the mean spherical approximation for simple electrolyte solutions; the representation of lattice sums as Mellin-transformed products of theta functions; and the evaluation of two-dimensional lattice sums by number theoretic means. The text also describes an application of contour integration; a lattice model of quantum fluid; as well as the computational aspects of chemical equilibrium in complex systems. Chemists and physicists will find the book usef

  1. 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

  2. Química de (nanomateriais Nano materials chemistry

    Directory of Open Access Journals (Sweden)

    Aldo J. G. Zarbin

    2007-12-01

    Full Text Available An overview of different aspects related to Materials and Nanomaterials Chemistry is presented and discussed. The insertion of this field in Brazil is evaluated on the basis of the communications presented on the 30th Annual Meeting of the Brazilian Chemical Society (SBQ. The importance of the Materials Chemistry Division of SBQ for the growth and consolidation of Materials Chemistry in Brazil is also discussed.

  3. Chemistry Notes

    Science.gov (United States)

    School Science Review, 1977

    1977-01-01

    Includes methods for determining melting and boiling points, illustrating the Finkelstein reaction, choosing acid-base indicators, growing perfect NaC1 cubes and "whiskers," bromination of alkenes, using vanadium in the laboratory, preparing phenylamine-copper (II) sulfate (VI) complex, simulating first-order chemical kinetics on a programmable…

  4. Chemistry Notes.

    Science.gov (United States)

    School Science Review, 1982

    1982-01-01

    Presents laboratory procedures, classroom materials/activities, and demonstrations, including: vapor pressure of liquid mixtures and Raoult's law; preparation/analysis of transition metal complexes of ethylammonium chloride; atomic structure display using a ZX81 (includes complete program listing); "pop-up" models of molecules and ions; reactions…

  5. Some electroanalytical investigations into the cure chemistry of industrial sealants

    OpenAIRE

    Raftery, Declan Patrick

    1996-01-01

    This thesis represents a study of the cure chemistry of three contrasting adhesive technologies, applying a range of analytical approaches to gain further insight into the complex chemistry of adhesives. An introduction is given in chapter one into the general chemistry of adhesives and their analysis, with particular emphasis on anaerobic adhesives and the crucial role played by transition metals in the cure chemistry. In order to elucidate the role played by tertiary amines and saccahri...

  6. The chemistry and mechanism of thermal degradation reactions of lanthanum(III) and praseodymium(III) complexes of acetylacetone-bis(thiosemicarbazones)

    International Nuclear Information System (INIS)

    The reactions of acetylacetone with 4-phenyl, 4-(2-chlorophenyl), 4-(4-nitrophenyl) and 4-(2-methylphenyl) thiosemicarbazide yields acetylacetone-bis(thiosemicarbazone) ligands (H2L). Lanthanum(III) and praseodymium(III) complexes with these ligands of the type (Ln(L)Cl(H2O)) have been prepared. The thermal behaviour of these compounds in non-isothermal conditions was investigated using TG, DTG and DSC techniques. The intermediates obtained at the end of various thermal decomposition steps were identified from elemental analyses and infrared spectral studies. The graphical method of Coats and Redfern was employed to evaluate the kinetic parameters such as apparent activation energy and order of reaction. The heats of reaction for the different decomposition steps were calculated from DSC curves. (author)

  7. Chemistry without Borders: Careers, Research, and Entrepreneurship

    Science.gov (United States)

    This book is based on two symposia of the American Chemical Society (ACS): 1) “The Transnational Practice of Chemistry and Allied Sciences and Engineering: Study, Research and Careers without Borders” held at the Spring National Meeting in Denver in March 2015, and 2) “International Entrepreneurship...

  8. 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

  9. 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.

  10. 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.

  11. Coordination chemistry of gadolinium complexes having pyridine carboxylate units in relation with the medical imagery; Chimie de coordination de complexes de gadolinium a motifs pyridine carboxylate en relation avec l'imagerie medicale

    Energy Technology Data Exchange (ETDEWEB)

    Gateau, C.; Chatterton, N.; Nonat, A.; Mazzanti, M. [CEA Grenoble, Dept. de Recherche Fondamentale sur la Matiere Condensee (DRFMC/SCIB/LAI) Lab. de Reconnaissance Ionique, 38 (France); Pecaut, J. [CEA Grenoble, Dept. de Recherche Fondamentale sur la Matiere Condensee (DRFMC/SCIB/LAI) Lab. de Coordination et Chiralite, 38 (France); Borel, A.; Merbach, A.; Heim, L. [Lausanne Univ., Institut de Chimie Minerale et Analytique (Switzerland)

    2005-07-01

    In order to study the influence of the coordination sphere on the properties which govern the relaxivity, ligands containing pyridine carboxylates units have been particularly studied. It has been shown that the tripodal ligand tpaa forms with gadolinium (III) a neutral complex having a relaxivity (r1p=13.3 mM{sup -1} at 298 K and 60 MHz) which is three times superior to the contrast agents currently used in NMR Imaging. To explain this remarkably relaxivity, two new ligands analogous to the tpaa: the tpatcn and the bpeda containing pyridine carboxylate units bound to one or several aliphatic nitrogen have been studied in modulating the number of coordination sites and the symmetry degree. The study of the relaxivity of the corresponding gadolinium (III) complexes gives precious data on the understanding of the results in the case of the complex [Gd(tpaa)]. The synthesis and the properties of these gadolinium (III) complexes will be presented during this conference. (O.M.)

  12. Electron microscopy of particles collected at Praia, Cape Verde, during the Saharan Mineral Dust Experiment: particle chemistry, shape, mixing state and complex refractive index

    Energy Technology Data Exchange (ETDEWEB)

    Kandler, K.; Lieke, K.; Benker, N. (Institut fur Angewandte Geowissenschaften, Technische Universitaet Darmstadt, Darmstadt (Germany)), e-mail: kzk@gmx.de (and others)

    2011-09-15

    A large field experiment of the Saharan Mineral Dust Experiment (SAMUM) was performed in Praia, Cape Verde, in January and February 2008. The aerosol at Praia is a superposition of mineral dust, sea-salt, sulphates and soot. Particles smaller than 500 nm are mainly mineral dust, mineral dust-sulphate mixtures, sulphates and soot-sulphate mixtures. Particles larger then 2.5mum consist of mineral dust, sea-salt and few mineral dust-sulphate mixtures. A transition range exists in between. The major internal mixtures are mineral dust-sulphate and soot-sulphate. Mineral dust-sea-salt mixtures occur occasionally, mineral dust-soot mixtures were not observed. The aspect ratio was 1.3-1.4 for dry particles smaller than 500 nm and 1.6-1.7 for larger ones. Parameterizations are given for dry and humid state. Although the real part of the refractive index showed low variation (1.55-1.58 at 532 nm), a multi-modal imaginary part was detected as function of particle size, reflecting the complex composition. Soot mainly influences the absorption for wavelengths longer than the haematite absorption edge, whereas for shorter wavelengths dust is dominating. The refractive index of the aerosol depends on the source region of the mineral dust and on the presence/absence of a marine component

  13. Coordination chemistry of Co complexes containing tridentate SNS ligands and their application as catalysts for the oxidation of n-octane.

    Science.gov (United States)

    Soobramoney, Lynette; Bala, Muhammad D; Friedrich, Holger B

    2014-11-14

    The selective oxidation of saturated hydrocarbons to terminal oxygenates under mild catalytic conditions has remained a centuries long challenge in chemical catalysis. In an attempt to address this challenge, two series of tridentate donor ligands {2,6-bis(RSCH2)pyridine and bis(RSCH2CH2)amine [R = alkyl, aryl]} and their respective cobalt complexes {Co[2,6-bis(RSCH2)pyridine]Cl2 and Co[bis(RSCH2CH2)amine]Cl2} were synthesized and characterized. Crystal structures of Co[2,6-bis(RSCH2)pyridine]Cl2 [R = -CH3 (), -CH2CH3 (), -CH2CH2CH2CH3 () and -C6H5 ()] are reported in which crystallized as a homo-bimetallic dimer that incorporated two bridging chloride atoms in an octahedral geometry around each cobalt center, while , and crystallized as mono-metallic species characterized by trigonal bipyramidal arrangement of ligands around each cobalt center. As catalysts for the homogeneous selective oxidation of n-octane, the catalysts yielded ketones as the dominant products with a selectivity of ca. 90% for the most active catalyst Co[bis(CH2CH2SCH2CH2)amine]Cl2 () at a total n-octane conversion of 23%. Using tert-butyl hydroperoxide (TBHP) as an oxidant, optimization of reaction conditions is also reported. PMID:25233287

  14. 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…

  15. General theory for multiple input-output perturbations in complex molecular systems. 1. Linear QSPR electronegativity models in physical, organic, and medicinal chemistry.

    Science.gov (United States)

    González-Díaz, Humberto; Arrasate, Sonia; Gómez-SanJuan, Asier; Sotomayor, Nuria; Lete, Esther; Besada-Porto, Lina; Ruso, Juan M

    2013-01-01

    In general perturbation methods starts with a known exact solution of a problem and add "small" variation terms in order to approach to a solution for a related problem without known exact solution. Perturbation theory has been widely used in almost all areas of science. Bhor's quantum model, Heisenberg's matrix mechanincs, Feyman diagrams, and Poincare's chaos model or "butterfly effect" in complex systems are examples of perturbation theories. On the other hand, the study of Quantitative Structure-Property Relationships (QSPR) in molecular complex systems is an ideal area for the application of perturbation theory. There are several problems with exact experimental solutions (new chemical reactions, physicochemical properties, drug activity and distribution, metabolic networks, etc.) in public databases like CHEMBL. However, in all these cases, we have an even larger list of related problems without known solutions. We need to know the change in all these properties after a perturbation of initial boundary conditions. It means, when we test large sets of similar, but different, compounds and/or chemical reactions under the slightly different conditions (temperature, time, solvents, enzymes, assays, protein targets, tissues, partition systems, organisms, etc.). However, to the best of our knowledge, there is no QSPR general-purpose perturbation theory to solve this problem. In this work, firstly we review general aspects and applications of both perturbation theory and QSPR models. Secondly, we formulate a general-purpose perturbation theory for multiple-boundary QSPR problems. Last, we develop three new QSPR-Perturbation theory models. The first model classify correctly >100,000 pairs of intra-molecular carbolithiations with 75-95% of Accuracy (Ac), Sensitivity (Sn), and Specificity (Sp). The model predicts probabilities of variations in the yield and enantiomeric excess of reactions due to at least one perturbation in boundary conditions (solvent, temperature

  16. 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...

  17. 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)

  18. 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)

  19. 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

  20. 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. ...

  1. Algorithmic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, W.

    1990-12-13

    In this paper complex adaptive systems are defined by a self- referential loop in which objects encode functions that act back on these objects. A model for this loop is presented. It uses a simple recursive formal language, derived from the lambda-calculus, to provide a semantics that maps character strings into functions that manipulate symbols on strings. The interaction between two functions, or algorithms, is defined naturally within the language through function composition, and results in the production of a new function. An iterated map acting on sets of functions and a corresponding graph representation are defined. Their properties are useful to discuss the behavior of a fixed size ensemble of randomly interacting functions. This function gas'', or Turning gas'', is studied under various conditions, and evolves cooperative interaction patterns of considerable intricacy. These patterns adapt under the influence of perturbations consisting in the addition of new random functions to the system. Different organizations emerge depending on the availability of self-replicators.

  2. 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.

  3. 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.

  4. 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.

  5. Advances in high temperature chemistry 1

    CERN Document Server

    Eyring, Leroy

    2013-01-01

    Advances in High Temperature Chemistry, Volume 1 describes the complexities and special and changing characteristics of high temperature chemistry. After providing a brief definition of high temperature chemistry, this nine-chapter book goes on describing the experiments and calculations of diatomic transition metal molecules, as well as the advances in applied wave mechanics that may contribute to an understanding of the bonding, structure, and spectra of the molecules of high temperature interest. The next chapter provides a summary of gaseous ternary compounds of the alkali metals used in

  6. Polysaccharides: The “Click” Chemistry Impact

    OpenAIRE

    Romain Lucas; Daniel Montplaisir; Rachida Zerrouki; Pierre-Antoine Faugeras; François Brouillette; Benjamin Boëns; Pierre-Henri Elchinger

    2011-01-01

    Polysaccharides are complex but essential compounds utilized in many areas such as biomaterials, drug delivery, cosmetics, food chemistry or renewable energy. Modifications and functionalizations of such polymers are often necessary to achieve molecular structures of interest. In this area, the emergence of the “click” chemistry concept, and particularly the copper-catalyzed version of the Huisgen 1,3-dipolar cycloaddition reaction between terminal acetylenes and azides, had an impact on the ...

  7. Organic chemistry experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mun, Seok Sik

    2005-02-15

    This book deals with organic chemistry experiments, it is divided five chapters, which have introduction, the way to write the experiment report and safety in the laboratory, basic experiment technic like recrystallization and extraction, a lot of organic chemistry experiments such as fischer esterification, ester hydrolysis, electrophilic aromatic substitution, aldol reaction, benzoin condensation, wittig reaction grignard reaction, epoxidation reaction and selective reduction. The last chapter introduces chemistry site on the internet and way to find out reference on chemistry.

  8. Density functional theory-based prediction of the formation constants of complexes of ammonia in aqueous solution: indications of the role of relativistic effects in the solution chemistry of gold(I).

    Science.gov (United States)

    Hancock, Robert D; Bartolotti, Libero J

    2005-10-01

    A prediction of the formation constants (log K1) for complexes of metal ions with a single NH3 ligand in aqueous solution, using quantum mechanical calculations, is reported. DeltaG values at 298 K in the gas phase for eq 1 (DeltaG(DFT)) were calculated for 34 metal ions using density functional theory (DFT), with the expectation that these would correlate with the free energy of complex formation in aqueous solution (DeltaG(aq)). [M(H2O)6]n+(g) + NH(3)(g) = [M(H2O)5NH3]n+(g) + H2O(g) (eq 1). The DeltaG(aq) values include the effects of complex changes in solvation on complex formation, which are not included in eq 1. It was anticipated that such changes in solvation would be constant or vary systematically with changes in the log K(1) value for different metal ions; therefore, simple correlations between DeltaG(DFT) and DeltaG(aq) were sought. The bulk of the log K1(NH3) values used to calculate DeltaG(aq) were not experimental, but estimated previously (Hancock 1978, 1980) from a variety of empirical correlations. Separate linear correlations between DeltaG(DFT) and DeltaG(aq) for metal ions of different charges (M2+, M3+, and M4+) were found. In plots of DeltaG(DFT) versus DeltaG(aq), the slopes ranged from 2.201 for M2+ ions down to 1.076 for M4+ ions, with intercepts increasing from M2+ to M4+ ions. Two separate correlations occurred for the M3+ ions, which appeared to correspond to small metal ions with a coordination number (CN) of 6 and to large metal ions with a higher CN in the vicinity of 7-9. The good correlation coefficients (R) in the range of 0.97-0.99 for all these separate correlations suggest that the approach used here may be the basis for future predictions of aqueous phase chemistry that would otherwise be experimentally inaccessible. Thus, the log K1(NH3) value for the transuranic Lr3+, which has a half-life of 3.6 h in its most stable isotope, is predicted to be 1.46. These calculations should also lead to a greater insight into the factors

  9. Impact of aircraft emissions on the atmospheric chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Dameris, M.; Sausen, R.; Grewe, V.; Koehler, I.; Ponater, M. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere; Steil, B. [Max-Planck-Inst. fuer Meteorologie, Hamburg (Germany); Bruehl, Ch. [Max-Planck-Inst. fuer Chemie (Otto-Hahn-Institut), Mainz (Germany)

    1997-12-31

    A hierarchy of models of different complexity has been applied to estimate the impact of aircraft NO{sub x} emissions on atmospheric chemistry. The global circulation model ECHAM3 has been coupled with two types of chemistry modules. The first of these describes only a simplified (linear) NO{sub x} and HNO{sub 3} chemistry while the second one is a comprehensive chemistry module (CHEM), describing tropospheric and stratospheric chemistry including photochemical reactions and heterogeneous reactions on sulphate aerosols and PSCs. The module CHEM has been coupled either off-line or with feedback via the ozone concentration. First results of multilayer integrations (over decades) are discussed. (author) 27 refs.

  10. 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)

  11. Protonolysis of Dialkyl- and Alkylarylplatinum(II) Complexes and Geometrical Isomerization of the Derived Monoorgano-Solvento Complexes: Clear-Cut Examples of Associative and Dissociative Pathways in Platinum(II) Chemistry.

    Science.gov (United States)

    Romeo, Raffaello; Plutino, Maria Rosaria; Elding, Lars I.

    1997-12-01

    Protonolysis of the complexes cis-[PtR(2)(PEt(3))(2)] (R = Me, Et, Pr(n)(), Bu(n)(), CH(2)C(Me)(3), CH(2)Si(Me)(3)) and cis-[Pt(R)(R')(PEt(3))(2)] (R = Ph, 2-MeC(6)H(4), 2,4,6-Me(3)C(6)H(2); R' = Me) in methanol selectively cleaves one alkyl group, yielding cis-[Pt(R)(PEt(3))(2)(MeOH)](+) and alkanes. The reactions occur as single-stage conversions from the substrate to the product. There is no evidence by UV and by low-temperature (1)H and (31)P NMR spectroscopy for the presence of significant amounts of Pt(II) or Pt(IV) intermediate species. Reactions are first order with respect to complex and proton concentrations and are strongly retarded by steric congestion at the Pt-C bond, varying from k(2) = (2.65 +/- 0.08) x 10(5) M(-)(1) s(-)(1) for R = R' = Et to k(2) = 9.80 +/- 0.44 M(-)(1)s(-)(1) for R = R'= CH(2)Si(Me)(3). Low enthalpies of activation and largely negative volumes of activation are associated with the process. The mechanism involves a rate-determining proton transfer either to the metal-carbon sigma bond (S(E)2 mechanism) or to the metal center (S(E)(oxidative) mechanism), followed by fast extrusion of the alkane and simultaneous blocking of the vacant coordination site by the solvent to generate cis-[Pt(R)(PEt(3))(2)(MeOH)](+) species. The subsequent slower process, cis to trans isomerization of cis-[Pt(R)(PEt(3))(2)(MeOH)](+), is characterized by high values of enthalpies of activation, positive entropies of activation, and largely positive volumes of activation. The reaction is shown to proceed through the dissociative loss of the weakly bonded molecule of solvent and the interconversion of two geometrically distinct T-shaped 14-electron 3-coordinate intermediates. The presence of beta-hydrogens on the residual alkyl chain produces a great acceleration of the rate (R = Me, k(i) = 0.0026 s(-)(1); R = Et, k(i) = 44.9 s(-)(1)) as a consequence of the stabilization of the 3-coordinate [Pt(R)(PEt(3))(2)](+) transition state through an incipient agostic

  12. A report of the first biennial meeting on Capita Selecta in Complex Disease Analysis (CSCDA2010), Leuven, Belgium, August 25-27, 2010.

    Science.gov (United States)

    Van Steen, Kristel; Sleegers, Kristel

    2011-07-01

    There is a need for interdisciplinary assessments and interpretations of -omics underpinnings of human complex diseases. However, often investigators from different, yet overlapping, disciplines experience difficulties in understanding the other discipline's language and there is a clear need for establishing a platform that nourishes interdisciplinary team processes and allows tearing down the professional's tower of Babel. To accommodate these needs, the biennial mini-conference Capita Selecta in Complex Disease Analysis was instigated. Abstracts are freely available online [http://www.aimontefiore.org/cscda2010/]. PMID:21668910

  13. 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

  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. Public meetings

    CERN Multimedia

    Staff Association

    2014-01-01

    You were hundreds of persons to participate in our information meetings of October 3 and 6 2014, and we thank you for your participation! The full presentation is available here. A summary of the topics is available here (in french).

  16. 51. Meeting of the Chemical Societies: Almanac of Contributions, Vol. Program, 1, 2, 3, 4 Molecular Models (Workshop)

    International Nuclear Information System (INIS)

    The publication has been set up as a abstracts of the meeting dealing with different chemical problems. The book (Vol. 1) consists of the sections: All-plenary lectures (9 papers); (D) History of the chemistry (14); (K) Didactics of chemistry (32); The book (Vol. 2) consists of the sections: (A) Analytical chemistry (48); (B) Inorganic chemistry (75); (C) Physical chemistry (27); (F) Nuclear chemistry and radioecology (12); (L) Environmental chemistry and toxicology (33); (M) Agricultural chemistry (20). The book (Vol. 3) consists of the sections: (E) Wood, pulp, paper (15); (G) Macromolecular chemistry (42); (H) Organic chemistry, bio-organic chemistry and pharmaceutical chemistry (96); (I) Food chemistry and biochemistry (34); (J) Textile, fibres and foil materials (9). The book (Vol. 4) consists of the workshop Molecular models (3 papers)

  17. Synthesis and first use of pyridine-2,6-diylbis(pyrazine-2-ylmethanone) in metal cluster chemistry: a {Mn(III)3Na2} complex with an ideal trigonal bipyramidal geometry.

    Science.gov (United States)

    Giannopoulos, Dimosthenis P; Wilson-Konderka, Cody; Gagnon, Kevin J; Teat, Simon J; Escuer, Albert; Metallinos, Costa; Stamatatos, Theocharis C

    2015-03-01

    The successful organic synthesis of a new dipyrazole/pyridine-dicarbonyl organic molecule, namely pyridine-2,6-diylbis(pyrazine-2-ylmethanone) [(pz)CO(py)CO(pz)], followed by its employment in Mn coordination chemistry has yielded the neutral cluster compound [Mn3Na2O(N3)3(L)3] (1), where L(2-) is the (pz)C(CH2COCH3)(O(-))(py)C(CH2COCH3)(O(-))(pz) dianion. The latter group was formed in situ, presumably by the nucleophilic attack of the carbanion (-)CH2COCH3 to the carbonyl carbon atoms of (pz)CO(py)CO(pz), in the presence of Mn(n+) ions under basic conditions and in solvent Me2CO. Complex 1 possesses an almost ideal trigonal bipyramidal topology, with the two Na(I) ions occupying the apical positions and the three Mn(III) ions residing in the equatorial trigonal plane. The bridging ligation about the metal ions is provided by a μ3-O(2-) ion and six μ-OR(-) groups from the L(2-) ligand, while peripheral ligation is completed by three terminal azido groups and the pyridine N and carbonyl O atoms of L(2-). Magnetic susceptibility studies revealed the presence of predominant antiferromagnetic exchange interactions between the paramagnetic Mn(III) centres; the use of an anisotropic, equilateral Mn(III)3 triangle model allowed us to fit the magnetic data and obtain the best-fit parameters: J = -10.8 cm(-1), D = -5.3 cm(-1), and g = 1.99. The combined results demonstrate the rich chemical reactivity of carbonyl groups and the ability of poly-ketone ligands to stabilize cluster compounds with unprecedented structural motifs and interesting architectures.

  18. 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

  19. 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.

  20. 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)

  1. Meeting the complex needs of urban youth and their families through the 4Rs 2Ss Family Strengthening Program: The “real world” meets evidence-informed care

    Science.gov (United States)

    Small, Latoya; Jackson, Jerrold; Gopalan, Geetha; McKay, Mary McKernan

    2014-01-01

    Youth living in poverty face compounding familial and environmental challenges in utilizing effective community mental health services. They have ongoing stressors that increase their dropout rate in mental health service use. Difficulties also exist in staying engaged in services when they are involved with the child welfare system. This study examines the 4Rs 2Ss Family Strengthening Program, developed across four broad conceptual categories related to parenting skills and family processes that form a multiple family group service delivery approach. A total of 321 families were enrolled in this randomized intervention study, assigned to either the 4Rs 2Ss Family Strengthening Program or standard care services. Caregivers and their children randomly assigned to the experimental condition received a 16 week multiple family group intervention through their respective outpatient community mental health clinic. Data was collected at baseline, midtest (8 weeks), posttest (16 weeks), and 6 month follow-up. Major findings include high engagement in the 4Rs 2Ss Family Strengthening Program, compared to standard services. Although child welfare status is not related to attendance, family stress and parental depression are also related to participant engagement in this multiple family group intervention. Involvement in the 4Rs 2Ss Family Strengthening Program resulted in improved effects for child behaviors. Lastly, no evidence of moderation effects on family stress, child welfare involvement, or parental needs were found. The 4Rs 2Ss Family Strengthening Program appeared able to engage families with more complex “real world” needs. PMID:26523115

  2. PrefaceThe Seventh Sino-US Chemistry Professors Conference: Bridging International Research Communities in Chemistry

    Institute of Scientific and Technical Information of China (English)

    CHEN Xi; SUO Zucai; HUANG Zhen; PU Lin

    2012-01-01

    The seventh Sino-US Chemistry Professors Conference,co-organized by Guizhou University (Professor Baoan Song as the chairman) and CAPA (The Chinese-American Chemistry & Chemical Biology Professors Association,USA;Professor Chuan He as the co-chairman) was successfully held in Huaxi,Guizhou,China on June 28-30,2011.Over 200 professors from China and abroad participated in this conference with three parallel sessions on synthetic chemistry,natural products,synthetic materials,medicinal chemistry,and chemical biology.There were 106 oral presentations and 15 poster presentations in this conference.We are indebted to our local hosts,Professor Baoan Song,the conference sectaries Professor Song Yang and Professor Cai-Guang Yang,and the staffs and students in the Center for Research and Development for Fine Chemicals of Guizhou University,for arranging the meeting in the historic Huaxi Guesthouse and their hospitality during the conference.

  3. Enlarged Halden programme group meeting on man-machine systems research and high burn-up fuel performance, safety and reliability and degradation of in-core materials and water chemistry effects. Volume I

    International Nuclear Information System (INIS)

    An Enlarged Halden Programme Group Meeting on Fuel Performance and Materials Testing and Man-Machine Research was held at Loen, Norway 24 to 29 May, 1999. The papers presented covered work performed at the OECD Halden Reactor Project during the years up to April 1999 as well as studies conducted within organisations participating in the Halden Project. The Halden Boiling Water Reactor, HBWR, was built in the years 1955 - 1958 by the Norwegian Institutt for Atomenergi, and has since 1958 been operated internationally as one of the joint undertakings of the OECD Nuclear Energy Agency. The experimental operation of the Halden Boiling Water Reactor and associated programmes are sponsored through an international agreement by Institute for energy technology, Norway, the Belgian Nuclear Research Centre SCK/CEN, acting also on behalf of other public or private organisations in Belgium, the Risoe National Laboratory in Denmark, the Finnish Ministry of Trade and Industry, the Electricite de France, the Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbH, representing a German group of companies working in agreement with the German Federal Ministry for Education, Science, Research and Technology, the Italian Ente per le Nouve Tecnologie, L'Energia e l'Ambiente, the Japan Atomic Energy Research Institute, the Korean Atomic Energy Research Institute, the Spanish Centre de Investigaciones Energeticas, Medioambientales y Tecnologias, representing a group of national and industry organisations in Spain, the Swedish Nuclear Power Inspectorate, the Swiss Federal Nuclear Safety Inspectorate, representing also the Swiss nuclear utilities and the Paul Scherrer Institute, the Nuclear Electric pic, representing a group of nuclear research and industry organisations in the United Kingdom, and the United States Nuclear Regulatory Commission, and as associated parties: the Brazilian Comissao Nacional de Energia Nuclear (CNEN), the Czech Nuclear Research Institute, the Hungarian

  4. Enlarged Halden programme group meeting on high burn-up fuel performance, safety and reliability and degradation of in-core materials and water chemistry effects and man-machine systems research. Volume I

    International Nuclear Information System (INIS)

    An Enlarged Halden Programme Group Meeting on Fuel Performance and Materials Testing and Man-Machine Research was held at Loen, Norway 24 to 29 May, 1999. The papers presented covered work performed at the OECD Halden Reactor Project during the years up to April 1999 as well as studies conducted within organisations participating in the Halden Project. The Halden Boiling Water Reactor, HBWR, was built in the years 1955 - 1958 by the Norwegian Institutt for Atomenergi, and has since 1958 been operated internationally as one of the joint undertakings of the OECD Nuclear Energy Agency. The experimental operation of the Halden Boiling Water Reactor and associated programmes are sponsored through an international agreement by Institute for energy technology, Norway, the Belgian Nuclear Research Centre SCK/CEN, acting also on behalf of other public or private organisations in Belgium, the Risoe National Laboratory in Denmark, the Finnish Ministry of Trade and Industry, the Electricite de France, the Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) mbH, representing a German group of companies working in agreement with the German Federal Ministry for Education, Science, Research and Technology, the Italian Ente per le Nouve Tecnologie, l'Energia e l'Ambiente, the Japan Atomic Energy Research Institute, the Korean Atomic Energy Research Institute, the Spanish Centre de Investigaciones Energeticas, Medioambientales y Tecnologias, representing a group of national and industry organisations in Spain, the Swedish Nuclear Power Inspectorate, the Swiss Federal Nuclear Safety Inspectorate, representing also the Swiss nuclear utilities and the Paul Scherrer Institute, the Nuclear Electric pic, representing a group of nuclear research and industry organisations in the United Kingdom, and the United States Nuclear Regulatory Commission, and as associated parties: the Brazilian Comissao Nacional de Energia Nuclear (CNEN), the Czech Nuclear Research Institute, the Hungarian

  5. The New Color of Chemistry: Green Chemistry

    OpenAIRE

    GERÇEK, Zuhal

    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...

  6. 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...

  7. 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'

  8. Nitrogen Compounds in Radiation Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Sims, H.E. [NNL Sellafield (United Kingdom); Dey, G.R. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Vaudey, C.E.; Peaucelle, C. [Institut de Physique Nucleaire de Lyon - IPNL, 69 - Lyon (France); Boucher, J.L. [Lab. de Chimie et Biochimie Pharmacologiques et Toxicologiques, UMR 8601 CNRS 45 rue des Saints Peres, 75270 Paris cedex 06, Univ Paris 5, 75 (France); Toulhoat, N. [Institut de Physique Nucleaire de Lyon (France); Commissariat a l' Energie Atomique CEA/DEN, Centre de Saclay (France); Bererd, N. [Institut de Physique Nucleaire de Lyon (France); IUT Departement Chimie, Universite Claude Bernard Lyon 1 (France); Koppenol, W.H. [Department of Chemistry and Applied Biosciences, ETH Zurich (Switzerland); Janata, E. [Helmholtz-Zentrum fuer Materialien und Energie, Solar Energy Research, Berlin (Germany); Dauvois, V.; Durand, D.; Legand, S.; Roujou, J.L.; Doizi, D.; Dannoux, A.; Lamouroux, C. [Laboratoire de Speciation des Radionucleides et des Molecules, DEN/DPC/Service d' Etude du Comportement des Radionucleides, CEA Saclay, 91 - Gif sur yvette (France)

    2009-07-01

    Water radiolysis in presence of N{sub 2} 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 N{sub 2} and moreover in absence of oxygen there is no agreement on the formation or not of nitrogen oxide like NO{sub 2}- and NO{sub 3}-. 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 N{sub 2}O saturated aqueous solution'; - V. DAUVOIS: 'Analytical strategy for the study of radiolysis gases'

  9. Patterns in Organometallic Chemistry with Application in Organic Synthesis.

    Science.gov (United States)

    Schwartz, Jeffrey; Labinger, Jay A.

    1980-01-01

    Of interest in this discussion of organometallic complexes are stoichiometric or catalytic reagents for organic synthesis in the complex transformations observed during synthesis for transition metal organometallic complexes. Detailed are general reaction types from which the chemistry or many transition metal organometallic complexes can be…

  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. Coordination Chemistry of 2,2'-Bipyridyl- and 2,2':6',2″-Terpyridyl-Substituted BEDT-TTFs: Formation of a Supramolecular Capsule Motif by the Iron(II) Tris Complex of 2,2'-Bipyridine-4-thiomethyl-BEDT-TTF.

    Science.gov (United States)

    Wang, Qiang; Martin, Lee; Blake, Alexander J; Day, Peter; Akutsu, Hiroki; Wallis, John D

    2016-09-01

    Molecules of tris(2,2'-bipyridine-4-thiomethyl-BEDT-TTF)iron(II) (BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene) assemble in pairs to form a novel supramolecular capsular structure in the solid state. Three BEDT-TTF residues from one complex lie in the three grooves between coordinated bipyridines of the other complex, and vice versa, to form a capsule with 3-fold rotational symmetry and an internal volume of ca. 160 Å(3). Further aspects of the coordination chemistry of this ligand, its 6-substituted isomer, and the 2,2':6'2″-terpyridyl-4'-thiomethyl-BEDT-TTF analogue are described.

  12. ACCU MEETING

    CERN Multimedia

    PH Department

    2010-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 September 2010 at 9:15 a.m. in Room 60-6-002 Chairperson’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS Department An update on Safety at CERN The CERN Summer Student program Bringing Library services to users Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairperson in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): ...

  13. ACCU Meeting

    CERN Multimedia

    PH Department

    2010-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 June 2010 At 9:15 a.m. in room 60-6-002 Chairperson’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department CERN Global Network An update on Safety at CERN Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairperson in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) ...

  14. ACCU Meeting

    CERN Multimedia

    PH Department

    2011-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 March 2011 At 9:15 a.m. in room 60-6-002   Chairperson's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department Update on Safety at CERN The new account management system Users’ Office news Any Other Business Agenda for the next meeting   Anyone wishing to raise any points under item 10 is invited to send them to the Chairperson in writing or by e-mail to Michael.Hauschild@cern.ch Michael Hauschild (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria G. Walzel (76592) Belgium ...

  15. ACCU Meeting

    CERN Multimedia

    PH Department

    2010-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 December 2010 at 9:15 a.m. in room 60-6-002 Chairperson's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department The CERN Ombuds The new account management system Crèche progress + Restaurants Reports from ACCU representatives on other committees Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairperson in writing or by e-mail to Michael.Hauschild@cern.ch   Michael Hauschild (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): ...

  16. Public meeting

    CERN Multimedia

    HR Department

    2010-01-01

    Dear Colleagues, I am pleased to invite you to a public meeting which will be held on Thursday 11 November 2010 at 2:30 p.m., in the Main Auditorium (welcome coffee from 2 p.m.) In this meeting Sigurd Lettow, Director for Administration and General Infrastructure will present the Management’s proposals towards restoring full funding of the Pension Fund. The meeting will follow discussions which took place with the Staff Association, at the Standing Concertation Committee (CCP) of 1 November 2010 and will be held with the Members States, at the Tripartite Employment Conditions Forum (TREF) of 4 November 2010. You will be able to attend this presentation in the Main Auditorium or via the webcast. The Management will also be available to reply to your questions on this subject. Best regards, Anne-Sylvie Catherin

  17. The 21st century chemistry journal

    OpenAIRE

    Steven M. Bachrach

    1999-01-01

    Internet publication will radically alter how chemists will publish their research in the next century. In this article, we describe two fundamental changes: enhanced chemical publication which allows chemists to publish materials that cannot be published on paper and end-user customization which allows readers to read articles prepared to meet their specifications. These concepts have been implemented within the Internet Journal of Chemistry, a new journal designed to employ the latest techn...

  18. Public meetings

    CERN Multimedia

    Staff Association

    2014-01-01

      Public meetings : Come and talk about your future employment conditions !   The Staff Association will come and present the results of our survey on the 2015 five-yearly review. Following the survey, the topics discussed, will be contract policy, recognition of merit (MARS), working time arrangements and family policy. After each meeting and around a cup of coffee or tea you will be able to continue the discussions. Do not hesitate to join us, the five-yearly review, it is with YOU!

  19. STAFF MEETING

    CERN Multimedia

    2003-01-01

    I would like to invite all members of the CERN Personnel to a meeting on Tuesday 13 January 2004 at 4:00 p.m. - Main Auditorium (bldg. 500) to convey my best wishes for the new year and to present a perspective of CERN's future activities. Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (bldg. 31) and the AT Auditorium (bldg. 30). A simultaneous translation into English will be available in the main Auditorium. Robert AYMAR

  20. STAFF MEETING

    CERN Multimedia

    2004-01-01

    I would like to invite all members of the CERN Personnel to a meeting on Tuesday 13 January 2004 at 4:00 p.m. - Main Auditorium (bldg. 500) to convey my best wishes for the new year and to present a perspective of CERN's future activities. Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (bldg. 31) and the AT Auditorium (bldg. 30). A simultaneous translation into English will be available in the main Auditorium. Robert AYMAR

  1. Bioscience methodologies in physical chemistry an engineering and molecular approach

    CERN Document Server

    D'Amore, Alberto

    2013-01-01

    The field of bioscience methodologies in physical chemistry stands at the intersection of the power and generality of classical and quantum physics with the minute molecular complexity of chemistry and biology. This book provides an application of physical principles in explaining and rationalizing chemical and biological phenomena. It does not stick to the classical topics that are conventionally considered as part of physical chemistry; instead it presents principles deciphered from a modern point of view, which is the strength of this book.

  2. 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...

  3. 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...

  4. 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

  5. ACCU MEETING

    CERN Document Server

    Chris Onions (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 December 2001 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 2. Adoption of the agenda 3. Minutes of the previous meeting 4. Matters arising 5. News from the CERN Management 6. Housing 7. Restaurant Surveillance Committee 8. Users' Office news 9. Election of ACCU chairman 10. Any Other Business 11. Dates for meetings in 2002 12. Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria  W. Adam  (71661) Belgium  G. Wilquet  (74664) Bulgaria  R. Tzenov  (77958) Czech Republic  P. Závada&am...

  6. ACCU MEETING

    CERN Multimedia

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 December 2000 At 10 a.m. in the 6th floor Conference Room, Main Building Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Equal Opportunities at CERN The Summer Student programme CERN Programme for Physics High School Teachers Users' Office News Any Other Business Dates for Meetings in 2001 Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) :   Austria G. Neuhofer (74094) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958)...

  7. ACCU MEETING

    CERN Multimedia

    Chris Onions (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 December 2001 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 2. Adoption of the agenda 3. Minutes of the previous meeting 4. Matters arising 5. News from the CERN Management 6. Housing 7. Restaurant Surveillance Committee 8. Users' Office news 9. Election of ACCU chairman 10. Any Other Business 11. Dates for meetings in 2002 12. Agenda for the next meetingAnyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland A. Kiiskinen (79387) Fr...

  8. ACCU MEETING

    CERN Multimedia

    Chris Onions (Secretary)

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 December 2000 At 10 a.m. in the 6th floor Conference Room, Main Building Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Equal Opportunities at CERN The Summer Student programme CERN Programme for Physics High School Teachers Users' Office News Any Other Business Dates for Meetings in 2001 Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) : Austria G. Neuhofer (74094) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Re...

  9. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 4 December 2002 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Fellows, Associates and Summer Student Programmes Particle Data Book distribution Revoking Computer accounts Equipment insurance on site Reports from ACCU representatives on other committees Users' Office news Any Other Business Dates for meetings in 2003 Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch   ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (74837...

  10. Crisis meeting

    CERN Multimedia

    Staff Association

    2014-01-01

      To all CERN staff: your rights are at risk ! We invite you to come to a crisis meeting on Wednesday 2nd April at 10:30 a.m., Auditorium, Main Building, Meyrin site. Your presence is crucial, we are ALL concerned !

  11. Crisis meeting

    CERN Multimedia

    Staff Association

    2015-01-01

    To all CERN staff: your rights are at risk! We invite you to come to a crisis meeting on Thursday 7th May 2015 at 9 a.m., Auditorium, Main Building, Meyrin site. Your presence is crucial, we are ALL concerned!

  12. ACCU Meeting

    CERN Multimedia

    PH Department

    2011-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 15 June 2011 At 9:15 a.m. in room 60-6-002 Chairperson’s remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on services from GS department Update on Safety at CERN Reports from ACCU representatives on other Committees a. Scientific Information Policy Board (SIPB) b. IT Service Review Meeting (ITSRM) c. GS User Commission Users’ Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairperson in writing or by e-mail to Michael.Hauschild@cern.ch Michael Hauschild (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in bra...

  13. 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....

  14. 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

  15. 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)

  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. Science Update: Analytical Chemistry.

    Science.gov (United States)

    Worthy, Ward

    1980-01-01

    Briefly discusses new instrumentation in the field of analytical chemistry. Advances in liquid chromatography, photoacoustic spectroscopy, the use of lasers, and mass spectrometry are also discussed. (CS)

  18. Grand Challenges in Chemistry for 2016 and Beyond

    OpenAIRE

    Bertozzi, Carolyn R.; Chang, Christopher J.; Davis, Benjamin G.; de la Cruz, Monica Olvera; Tirrell, David A.; Zhao, Dongyuan

    2016-01-01

    When several ACS Central Science Editors met for dinner at the 2015 Pacifichem meeting, conversation turned to the grand challenges facing science and society, and those we felt chemistry was in a unique position to solve. With the New Year, we thought we would share our ideas in our first editorial of 2016. The arenas in which we see chemistry having the largest influence are the molecular bases of disease and aging, alternative energy advancement, and the conservatio...

  19. 2. Working Meeting on Radiation Interaction

    International Nuclear Information System (INIS)

    The following topics have been discussed during the meeting: (1) elementary processes of radiation chemistry, (2) particle-induced x-ray emission, (3) special radiation-induced physical and chemical phenomena in matter, and (4) industrial application of radiation techniques. 104 summaries are included

  20. Photocytotoxic lanthanide complexes

    Indian Academy of Sciences (India)

    Akhtar Hussain; Akhil R Chakravarty

    2012-11-01

    Lanthanide complexes have recently received considerable attention in the field of therapeutic and diagnostic medicines. Among many applications of lanthanides, gadolinium complexes are used as magnetic resonance imaging (MRI) contrast agents in clinical radiology and luminescent lanthanides for bioanalysis, imaging and sensing. The chemistry of photoactive lanthanide complexes showing biological applications is of recent origin. Photodynamic therapy (PDT) is a non-invasive treatment modality of cancer using a photosensitizer drug and light. This review primarily focuses on different aspects of the chemistry of lanthanide complexes showing photoactivated DNA cleavage activity and cytotoxicity in cancer cells. Macrocyclic texaphyrin-lanthanide complexes are known to show photocytotoxicity with the PDT effect in near-IR light. Very recently, non-macrocyclic lanthanide complexes are reported to show photocytotoxicity in cancer cells. Attempts have been made in this perspective article to review and highlight the photocytotoxic behaviour of various lanthanide complexes for their potential photochemotherapeutic applications.

  1. Recent advances in the field of recoil chemistry

    International Nuclear Information System (INIS)

    Recent advances in the field of recoil chemistry are summarized and discussed. As important aids to furthering our knowledge of complex systems, the role is emphasized of new techniques such as vapour-phase chromatography, ion exchange and paper electrophoresis. An attempt is made to relate current work in recoil chemistry to other fields of investigation. (author)

  2. Molecular Modeling and Computational Chemistry at Humboldt State University.

    Science.gov (United States)

    Paselk, Richard A.; Zoellner, Robert W.

    2002-01-01

    Describes a molecular modeling and computational chemistry (MM&CC) facility for undergraduate instruction and research at Humboldt State University. This facility complex allows the introduction of MM&CC throughout the chemistry curriculum with tailored experiments in general, organic, and inorganic courses as well as a new molecular modeling…

  3. 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.

  4. 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)

  5. 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)

  6. 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)

  7. Photoredox Catalysis in Organic Chemistry

    Science.gov (United States)

    2016-01-01

    In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon–carbon and carbon–heteroatom bonds. PMID:27477076

  8. Photoredox Catalysis in Organic Chemistry.

    Science.gov (United States)

    Shaw, Megan H; Twilton, Jack; MacMillan, David W C

    2016-08-19

    In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon-carbon and carbon-heteroatom bonds. PMID:27477076

  9. Photoredox Catalysis in Organic Chemistry.

    Science.gov (United States)

    Shaw, Megan H; Twilton, Jack; MacMillan, David W C

    2016-08-19

    In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon-carbon and carbon-heteroatom bonds.

  10. Organic chemistry of elemental phosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Milyukov, V A; Budnikova, Yulia H; Sinyashin, Oleg G [A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Centre of the Russian Academy of Sciences, Kazan (Russian Federation)

    2005-09-30

    The principal achievements and the modern trends in the development of the chemistry of elemental phosphorus are analysed, described systematically and generalised. The possibilities and advantages of the preparation of organophosphorus compounds directly from white phosphorus are demonstrated. Attention is focused on the activation and transformation of elemental phosphorus in the coordination sphere of transition metal complexes. The mechanisms of the reactions of white phosphorus with nucleophilic and electrophilic reagents are discussed. Electrochemical approaches to the synthesis of organic phosphorus derivatives based on white phosphorus are considered.

  11. Advances in high temperature chemistry

    CERN Document Server

    Eyring, Leroy

    1969-01-01

    Advances in High Temperature Chemistry, Volume 2 covers the advances in the knowledge of the high temperature behavior of materials and the complex and unfamiliar characteristics of matter at high temperature. The book discusses the dissociation energies and free energy functions of gaseous monoxides; the matrix-isolation technique applied to high temperature molecules; and the main features, the techniques for the production, detection, and diagnosis, and the applications of molecular beams in high temperatures. The text also describes the chemical research in streaming thermal plasmas, as w

  12. Specialists' meeting on carbon in sodium. Summary report

    International Nuclear Information System (INIS)

    The purpose of the meeting was to provide a forum for the exchange of views on: the chemistry and thermodynamics of carbon in sodium; the analysis and monitoring of carbon in sodium; the behaviour of carbon in sodium circuits; and the implications of the above in LMFBRs. The technical parts of the meeting were divided into five major sessions

  13. Fission product chemistry in severe nuclear reactor accidents

    International Nuclear Information System (INIS)

    A specialist's meeting was held at JRC-Ispra from 15 to 17 January 1990 to review the current understanding of fission-product chemistry during severe accidents in light water reactors. Discussions focussed on the important chemical phenomena that could occur across the wide range of conditions of a damaged nuclear plant. Recommendations for future chemistry work were made covering the following areas: (a) fuel degradation and fission-product release, (b) transport and attenuation processes in the reactor coolant system, (c) containment chemistry (iodine behaviour and core-concrete interactions)

  14. 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.

  15. 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…

  16. 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...

  17. Career Options in Chemistry.

    Science.gov (United States)

    Belloli, Robert C.

    1985-01-01

    Describes a credit/no credit course which focuses on career options in chemistry. The course (consisting of 15 one-hour seminar-type sessions) includes guest speakers for several sessions and an emphasis (in introductory sessions) on graduate school in chemistry, the chemical industry, resumes, and interviews. Also briefly describes an internship…

  18. 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)....

  19. 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)

  20. Public meetings

    CERN Multimedia

    Staff Association

    2012-01-01

    MARS PENSIONS CONTRACT POLICY GENERAL INFORMATION   PUBLIC MEETINGS COME AND BE INFORMED! Public meetings Monday 15 Oct. 2 pm Amphi IT, 31-3-004 Meyrin Wednesday 17 Oct. 10 am Amphi BE, 864-1-D02 Prévessin Thursday 18 Oct. 10 am Salle du Conseil/ Council Chamber 503-1-001 Meyrin Thursday 18 Oct. 2 pm Filtration Plant, 222-R-001(in English) Meyrin   Overview of the topics to be discussed Recognition of Merit – MARS Outcome of last exercise 2007 to 2012 : lessons learned Pension Fund Capital preservation policy : what is it ? Contract policy LC2IC statistics SA proposal General information CVI 2013 Voluntary programmes (PRP, SLS)  

  1. Staff meeting

    CERN Multimedia

    2007-01-01

    I would like to invite all members of the CERN Personnel to a meeting on Wednesday 16 January 2008 at 3:00 p.m. Main Auditorium (bldg 500) to convey my best wishes for the new year, to review CERN’s activities during 2007 and to present the perspectives for 2008, the year of the LHC start-up. Closed-circuit transmission of the meeting will be available in the Council Chamber and in the AB Auditorium (Meyrin), the AB Auditorium (Prévessin), the IT Auditorium (Bldg. 31) and the AT Auditorium (Bldg. 30). Simultaneous translation into English will be available in the main Auditorium. Best wishes for the festive season! Robert AYMAR

  2. Playing with Liquid Foams: Learning Physical Chemistry

    Science.gov (United States)

    Ritacco, Hernan

    2008-01-01

    Who has never played with soap bubbles? They are so beautiful and amazing, they have a perfect spherical shape and surprising tints. Foams are structures of bubbles of an incredible complexity and they are a perfect system to stimulate students' interest in the chemistry and physics of surface phenomena. In this article I propose a simple…

  3. Hydrated Cations in the General Chemistry Course.

    Science.gov (United States)

    Kauffman, George B.; Baxter, John F., Jr.

    1981-01-01

    Presents selected information regarding the descriptive chemistry of the common metal ions and their compounds, including the concepts of process of solution, polar molecules, ionic size and charge, complex ions, coordination number, and the Bronsted-Lowry acid-base theory. (CS)

  4. Chemistry Education: Ten Facets to Shape Us

    Science.gov (United States)

    Talanquer, Vicente

    2013-01-01

    The chemistry knowledge that we want our students to develop is rich, complex, and multifaceted. However, some teachers and instructors at the secondary school and college levels approach it in rather rigid and unidimensional ways. The central goal of this contribution is to describe and discuss 10 different complementary perspectives or…

  5. Stratospheric General Circulation with Chemistry Model (SGCCM)

    Science.gov (United States)

    Rood, Richard B.; Douglass, Anne R.; Geller, Marvin A.; Kaye, Jack A.; Nielsen, J. Eric; Rosenfield, Joan E.; Stolarski, Richard S.

    1990-01-01

    In the past two years constituent transport and chemistry experiments have been performed using both simple single constituent models and more complex reservoir species models. Winds for these experiments have been taken from the data assimilation effort, Stratospheric Data Analysis System (STRATAN).

  6. 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

  7. 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

  8. ACCU MEETING

    CERN Multimedia

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 September 2000 At 10 a.m. in the 6th floor Conference Room, Main Building 1. Chairman's remarks 2. Adoption of the agenda 3. News from the CERN Management 4. Minutes of the previous meeting 5. Matters arising 6. Report from the Scientific Information Policy Board 7. Report from ETT Division: The Press Office 8. Update on Computing Issues 9. Users' Office News 10. Any Other Business 11. Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Bryan Pattison (Secretary). ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) : Austria G. Neuhofer (74094) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Z vada (75...

  9. ACCU MEETING

    CERN Multimedia

    Chris Onions/EP (Secretary)

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 June 2001 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising EP Space management Cars Housing EDH from the User's point of view VRVS Users' Office News Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland A. Kiiskinen (79387) France M. Déj...

  10. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2001-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 March 2001 At 9:15 a.m. in the 6th floor Conference Room, Main Building Chairman's remarks Adoption of the agenda News from the CERN Management Minutes of the previous meeting Matters arising Video-conferencing/recording Fellows programme Operational Circular No. 6 EP Space management Update on Computing Issues Users' Office News Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 12 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary)  ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic...

  11. ACCU MEETING

    CERN Multimedia

    Bryan Pattison

    2000-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 September 2000 At 10 a.m. in the 6th floor Conference Room, Main Building1. Chairman's remarks2. Adoption of the agenda3. News from the CERN Management4. Minutes of the previous meeting5. Matters arising6. Report from the Scientific Information Policy Board7. Report from ETT Division: The Press Office8. Update on Computing Issues9. Users' Office News10. Any Other Business11. Agenda for the next meetingAnyone wishing to raise any points under item 10 is invited to send them to the Secretary in writing via the CERN Users' Office or by e-mail toBryan Pattison(Secretary).ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets) :Austria G. Neuhofer (74094)Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958)Czech Republic P. Závada (75877)Den...

  12. ACCU MEETING

    CERN Document Server

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 March 2002 At 9:15 a.m. in the Council Chamber Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Follow-up on Space Management Users' Desktop needs PIE procedures Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland E. Tuominen (71534) France F. Bauer L. Serin (712...

  13. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2005-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 December 2005 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Closure of computer accounts upon CERN contract expiry Reports from ACCU representatives on other committees Users' Office news Election of ACCU Chair Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets). Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) ...

  14. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 December 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting The effects of the reorganization of CERN's structure, one year on Matters arising News from the CERN Management Computer Security The new CERN Dosimeter Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (7594...

  15. ACCU Meeting

    CERN Multimedia

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 March 2007 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car-sharing pilot project Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Kunne S. La...

  16. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 December 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 8. Report from IT division on Computing matters 2. Adoption of the agenda 9. Young Particle Physicists Association 3. Minutes of the previous meeting 10. Reports from ACCU representatives on other committees 4. Matters arising 11. Users' Office news 5. News from the CERN Management 12. Election of the ACCU Chair 6. Report from the new Director-General 13. Any Other Business 7. CERN's 50th anniversary 14. Agenda for the next meeting Anyone wishing to raise any points under item 13 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Ada...

  17. ACCU MEETING

    CERN Document Server

    2006-01-01

    DRAFT Agenda of the meeting to be held on Wednesday 6 September 2006 at 9:15 a.m. in Room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Report on Fellows and Associates Programme Overview of safety at CERN Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under Item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K....

  18. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 11 June 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 7. Reports from ACCU representatives 2. Adoption of the agenda on other committees 3. Minutes of the previous meeting 8. Users' Office news 4. Matters arising 9. Any Other Business 5. News from the CERN Management 10. Agenda for the next meeting 6. Property Protection at CERN Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (75917) Bulgaria R. Tsenov (74837) Portugal P. Bordalo (74704) Czech Republic ...

  19. ACCU Meeting

    CERN Multimedia

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 7 March 2007 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car-sharing pilot project Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Kunne S. ...

  20. ACCU Meeting

    CERN Document Server

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 September 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management The Visits Service Lifetime of Computer Accounts Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Bauer (7...

  1. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 December 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 8. Report from IT division on Computing matters 2. Adoption of the agenda 9. Young Particle Physicists Association 3. Minutes of the previous meeting 10. Reports from ACCU representatives on other committees 4. Matters arising 11. Users' Office news 5. News from the CERN Management 12. Election of the ACCU Chair 6. Report from the new Director-General 13. Any Other Business 7. CERN's 50th anniversary 14. Agenda for the next meeting Anyone wishing to raise any points under item 13 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (716...

  2. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 14 June 2006 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car sharing pilot project The CERN Document Server : the portal to Open Access Videoconferencing and collaborative tools at CERN Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (7...

  3. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 June 2004 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Update on CERN's 50th anniversary celebrations Report from the EPOG (European Particle Physics Outreach Group) Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finlan...

  4. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 June 2004 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Update on CERN's 50th anniversary celebrations Report from the EPOG (European Particle Physics Outreach Group) Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark P. Hansen (75941...

  5. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 12 June 2002 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management PIE procedures CERN Cars EP Electronics Advisory Board Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch   ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland E. Tuominen (71534) France F. Bauer (71247) L. Serin (71143) Germany H. Kroha...

  6. ACCU Meeting

    CERN Document Server

    Chris Onions

    2006-01-01

    DRAFT Agenda of the meeting to be held on Wednesday 8 March 2006 At 9:15 a.m. in Room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Proposal for a centralised access control service Report from PH Space Management Policy Board Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under Item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives on ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) ...

  7. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 March 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 7. Equipment insurance on site 2. Adoption of the agenda,8. ACCU reporting mechanisms in the different countries 3. Minutes of the previous meeting9. Reports from ACCU representatives on other committees 4. Matters arising10. Users' Office news 5. News from the CERN Management11. Any Other Business 6. CHIS news and follow-up of survey12. Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661)NorwayH. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (7591...

  8. ACCU MEETING

    CERN Document Server

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 June 2007 at 9:15 a.m. in room 60-6-002 1.\tChairman’s remarks 6.\tDosimetry at CERN 2.\tAdoption of the agenda 7.\tStatus of collaborative tools at CERN 3.\tMinutes of the previous meeting 8.\tReports from ACCU representatives on other committees 4.\tMatters arising 9.\tUsers’ Office newss 5.\tNews from the CERN Management 10.\tAny Other Business 11.\tAgenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway G. Løvhøiden (73176) Belgium G. Wilquet (74664) Poland M. Witek (78967) Bulgaria Portugal...

  9. ACCU Meeting

    CERN Document Server

    Chris Onions

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 14 June 2006 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Car sharing pilot project The CERN Document Server : the portal to Open Access Videoconferencing and collaborative tools at CERN Reports from ACCU representatives on other committees Users'Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) ...

  10. ACCU Meeting

    CERN Multimedia

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 March 2004 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 6. The PH Department 2. Adoption of the agenda 7. Reports from ACCU representatives on other committees 3. Minutes of the previous meeting 8. Users' Office news 4. News from the CERN Management 9. Any Other Business 5. Matters arising 10. Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wilquet (74664) Poland Z. Hajduk (75917) Bulgaria R. Tsenov (79573) Portugal P. Bordalo (74704) Czech Republic P. Závada ...

  11. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 September 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management The Visits Service Lifetime of Computer Accounts Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finland K. Lassila-Perini (79354) France F. Bauer (...

  12. ACCU MEETING

    CERN Multimedia

    2006-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 6 September 2006 at 9:15 a.m. in room 60-6-002 1.     Chairman's remarks 2.     Adoption of the agenda 3.     Minutes of the previous meeting 4.     Matters arising 5.     News from the CERN Management 6.     Report on Fellows and Associates programme 7.     Overview of safety at CERN 8.     Reports from ACCU representatives on other committees 9.     Users' Office news 10.  Any Other Business 11.  Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets):Austria W. Adam  (71661) Belgium G. Wilquet (74664) Bulgaria ...

  13. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 10 March 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting News from the CERN Management Matters arising The PH Department Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 9 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finland E. Tuominen (71534) France F. Bauer (71247) L. Serin...

  14. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2004-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 December 2004 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting The effects of the reorganization of CERN's structure, one year on Matters arising News from the CERN Management Computer Security The new CERN Dosimeter Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark P. Hansen (75941) Finl...

  15. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2006-01-01

    DRAFT Agendafor the meeting to be held on Wednesday 8 March 2006At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Proposal for a centralised access control service Report from PH Space Management Policy Board Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Fin...

  16. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2002-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 12 June 2002 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management PIE procedures CERN Cars EP Electronics Advisory Board Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch   ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tzenov (77958) Czech Republic P. Závada (75877) Denmark A. Waananen (75941) Finland E. Tuominen (71534) France F. Bauer (71247) L. Serin (71143) Germany H. Kroha ...

  17. ACCU MEETING

    CERN Multimedia

    Chris Onions

    2007-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 13 June 2007 at 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Dosimetry at CERN Status of collaborative tools at CERN Reports from ACCU representatives on other committees Users' Office newss Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini (7935...

  18. ACCU MEETING

    CERN Multimedia

    2003-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 5 March 2003 At 9:15 a.m. in room 60-6-002 1. Chairman's remarks 7. Equipment insurance on site 2. Adoption of the agenda 8. ACCU reporting mechanisms in the different countries 3. Minutes of the previous meeting 9. Reports from ACCU representatives on other committees 4. Matters arising 10. Users' Office news 5. News from the CERN Management 11. Any Other Business 6. Health Insurance news and follow-up of survey 12. Agenda for the next meeting Anyone wishing to raise any points under item 11 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Norway H. Helstrup (73601) Belgium G. Wil...

  19. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2005-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 8 June 2005 At 9:15 a.m. in room 60-6-002 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Logistics at CERN Open Access Publishing Reports from ACCU representatives on other committees Users' Office news Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Lassila-Perini ...

  20. ACCU Meeting

    CERN Multimedia

    Chris Onions

    2005-01-01

    DRAFT Agenda for the meeting to be held on Wednesday 9 March 2005 At 9:15 a.m. in room 160-1-009 Chairman's remarks Adoption of the agenda Minutes of the previous meeting Matters arising News from the CERN Management Purchasing procedures at CERN Reports from ACCU representatives on other committees Users' Office news CERN Clubs Any Other Business Agenda for the next meeting Anyone wishing to raise any points under item 10 is invited to send them to the Chairman in writing or by e-mail to Christopher.Onions@cern.ch Chris Onions (Secretary) ACCU is the forum for discussion between the CERN Management and the representatives of CERN Users to review the practical means taken by CERN for the work of Users of the Laboratory. The User Representatives to ACCU are (CERN internal telephone numbers in brackets): Austria W. Adam (71661) Belgium G. Wilquet (74664) Bulgaria R. Tsenov (79573) Czech Republic P. Závada (75877) Denmark J.B. Hansen (75941) Finland K. Las...