WorldWideScience

Sample records for scale chemistry progress

  1. Progress in physical chemistry

    CERN Document Server

    Hempelmann, Rolf

    2008-01-01

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

  2. Recent progress in ellagitannin chemistry.

    Science.gov (United States)

    Feldman, Ken S

    2005-09-01

    Continuing studies on the total synthesis of ellagitannin plant metabolites have led to the preparation of the dimeric antitumor compound, coriariin A, as well as designed structural analogues. In related investigations, the synthesis of a 2,4-hexahydroxydiphenoyl (HHDP)-bearing glucopyranose structure has been achieved. This species is related to the geraniin family of ellagitannins, and its subsequent chemistry is suggestive of a mechanistic rationale for the observation that the HHDP units within (3,6-bridged)2,4-HHDP-containing ellagitannins invariably are oxidized further in vivo. Companion studies designed to assay the immunomodulatory properties of coriariin A and analogues have led to the thesis that tumor necrosis factor alpha (TNFalpha) serves as a mediator of this ellagitannin's tumor remissive activity. Furthermore, certain tannins and tannin analogues appear to act in an immunosuppressive capacity with peripheral blood monocytes that were exposed to the bacterially derived septic shock inducing agent lipid A.

  3. Bioorthogonal chemistry: recent progress and future directions.

    Science.gov (United States)

    Lim, Reyna K V; Lin, Qing

    2010-03-14

    The ability to use covalent chemistry to label biomolecules selectively in their native habitats has greatly enhanced our understanding of biomolecular dynamics and function beyond what is possible with genetic tools alone. To attain the exquisite selectivity that is essential in this covalent approach a "bottom-up" two-step strategy has achieved many successes recently. In this approach, a bioorthogonal chemical functionality is built into life's basic building blocks-amino acids, nucleosides, lipids, and sugars-as well as coenzymes; after the incorporation, an array of biophysical probes are selectively appended to the tagged biomolecules via a suitable bioorthogonal reaction. While much has been accomplished in the expansion of non-natural building blocks carrying unique chemical moieties, the dearth of robust bioorthogonal reactions has limited both the scope and utility of this promising approach. Here, we summarize the recent progress in the development of bioorthogonal reactions and their applications in various biological systems. A major emphasis has been placed on the mechanistic and kinetic studies of these reactions with the hope that continuous improvements can be made with each reaction in the future. In view of the gap between the capabilities of the current repertoire of bioorthogonal reactions and the unmet needs of outstanding biological problems, we also strive to project the future directions of this rapidly developing field.

  4. Chemistry Division annual progress report for period ending January 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    1984-05-01

    Progress is reported in the following fields: coal chemistry, aqueous chemistry at high temperatures and pressures, geochemistry, high-temperature chemistry and thermodynamics of structural materials, chemistry of transuranium elements and compounds, separations chemistry, elecrochemistry, catalysis, chemical physics, theoretical chemistry, nuclear waste chemistry, chemistry of hazardous chemicals, and thermal energy storage.

  5. Chemistry-Nuclear Chemistry Division. Progress report, October 1980-September 1981

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R.R. (comp.)

    1982-05-01

    This report describes major progress in the research and development programs pursued by the Chemistry-Nuclear Chemistry Division of the Los Alamos National Laboratory during FY 1981. Topics covered include advanced analytical methods, atmospheric chemistry and transport, biochemistry, biomedical research, medical radioisotopes research, element migration and fixation, nuclear waste isolation research, inorganic and structural chemistry, isotope separation, analysis and applications, the newly established Nuclear Magnetic Resonance Center, atomic and molecular collisions, molecular spectroscopy, nuclear cosmochemistry, nuclear structure and reactions, pion charge exchange, radiochemical separations, theoretical chemistry, and unclassified weapons research.

  6. Natural products chemistry research: progress in China in 2011.

    Science.gov (United States)

    Ye, Yang; Li, Xi-Qiang; Tang, Chun-Ping; Yao, Sheng

    2013-03-01

    This article reviews the progress made by Chinese scientists in the field of natural products chemistry in 2011. Selected compounds with unique structural features and/or promising bioactivities are described herein on the basis of structural types. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  7. Natural products chemistry research 2010's progress in China.

    Science.gov (United States)

    Ye, Yang; Li, Xi-Qiang; Tang, Chun-Ping; Yao, Sheng

    2012-01-01

    This article reviews the progresses made by Chinese scientists in the field of natural products chemistry in 2010. Selected compounds with unique structural features and/or promising bioactivities were described herein on the basis of structural types. Copyright © 2012 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  8. Analytical Chemistry Laboratory progress report for FY 1999

    Energy Technology Data Exchange (ETDEWEB)

    Green, D. W.; Boparai, A. S.; Bowers, D. L.; Graczyk, D. G.

    2000-06-15

    This report summarizes the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1999 (October 1998 through September 1999). This annual progress report, which is the sixteenth in this series for the ACL, describes effort on continuing projects, work on new projects, and contributions of the ACL staff to various programs at ANL.

  9. On Study of New Progress and Application of Coordination Chemistry in Chemistry and Chemical Industry in Recent Years

    Science.gov (United States)

    Zhang, Yunshen

    2017-12-01

    Coordination chemistry refers to a branch of chemistry, and its research results are widely used in industry and people's daily life. Many edge disciplines emerge during the development, which propels the process of disciplines and technology. This paper briefly discusses new progress of coordination chemistry and its application in chemistry and chemical industry in recent years.

  10. Small-scale chemistry for a hands-on approach to chemistry ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the possibility of using a small-scale chemistry (SSC) approach as a means of performing chemistry practical activities in Ethiopian secondary schools. A total of eight experiments from two topics, electrolysis and rate of reaction, in the Ethiopian grade 11 chemistry syllabus were ...

  11. Analytical chemistry laboratory. Progress report for FY 1997

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Boparai, A.S.; Bowers, D.L. [and others

    1997-12-01

    The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1997 (October 1996 through September 1997). This annual progress report is the fourteenth in this series for the ACL, and it describes continuing effort on projects, work on new projects, and contributions of the ACL staff to various programs at ANL.

  12. How Do Undergraduate Students Conceptualize Acid-Base Chemistry? Measurement of a Concept Progression

    Science.gov (United States)

    Romine, William L.; Todd, Amber N.; Clark, Travis B.

    2016-01-01

    We developed and validated a new instrument, called "Measuring Concept progressions in Acid-Base chemistry" (MCAB) and used it to better understand the progression of undergraduate students' understandings about acid-base chemistry. Items were developed based on an existing learning progression for acid-base chemistry. We used the Rasch…

  13. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 2000

    DEFF Research Database (Denmark)

    2001-01-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 2000 are presented in this progress report. Theresearch in physics is concentrated on neutron...... and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures.The research in chemistry includes chemical synthesis and physico-chemical investigation of small...

  14. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1999

    DEFF Research Database (Denmark)

    2000-01-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1999 are presented in this progress report. Theresearch in physics is concentrated on neutron...... and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small...

  15. Progress of modern agricultural chemistry and future prospects.

    Science.gov (United States)

    Jeschke, Peter

    2016-03-01

    Agriculture is facing an enormous challenge: it must ensure that enough high-quality food is available to meet the needs of a continually growing population. Current and future agronomic production of food, feed, fuel and fibre requires innovative solutions for existing and future challenges, such as climate change, resistance to pests, increased regulatory demands, renewable raw materials or requirements resulting from food chain partnerships. Modern agricultural chemistry has to support farmers to manage these tasks. Today, the so-called 'side effects' of agrochemicals regarding yield and quality are gaining more importance. Agrochemical companies with a strong research and development focus will have the opportunity to shape the future of agriculture by delivering innovative integrated solutions. This review gives a comprehensive overview of the innovative products launched over the past 10 years and describes the progress of modern agricultural chemistry and its future prospects. © 2015 Society of Chemical Industry.

  16. Green chemistry applied to corrosion and scale inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Darling, D.; Rakshpal, R. [Environmental Protection Agency, Washington, DC (United States)

    1998-12-31

    Numerous breakthroughs in environmental protection and pollution prevention have been realized in recent years by both industry and academia through the application of green chemistry principles. Green chemistry, or pollution prevention at the molecular level, is chemistry designed to reduce or eliminate the use or generation of hazardous materials associated with the manufacture and application of chemicals. The application of the green chemistry principles to the areas of corrosion and scale inhibitors has resulted in the reduction/elimination of many of the more toxic inhibitors and the development of newer, more environmentally friendly ones.

  17. Recent Progress in Large-Scale Structure

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    I will discuss recent progress in the understanding of how to model galaxy clustering. While recent analyses have focussed on the baryon acoustic oscillations as a probe of cosmology, galaxy redshift surveys contain a lot more information than the acoustic scale. In extracting this additional information three main issues need to be well understood: nonlinear evolution of matter fluctuations, galaxy bias and redshift-space distortions. I will present recent progress in modeling these three effects that pave the way to constraining cosmology and galaxy formation with increased precision.

  18. Annual progress report of the Condensed Matter Physics and Chemistry Department. 1 January - 31 December 2000

    Energy Technology Data Exchange (ETDEWEB)

    Lebech, B. [ed.

    2001-03-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 2000 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

  19. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1997

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, M.; Bechgaard, K.; Clausen, K.N.; Feidenhans`l, R.; Johannsen, I. [eds.

    1998-01-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1997 are presented in this progress report. The research in physics in concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems in undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au). 129 ills., 213 refs.

  20. Annual progress report of the Condensed Matter Physics and Chemistry Department 1 January - 31 December 1998

    Energy Technology Data Exchange (ETDEWEB)

    Bechgaard, K.; Clausen, K.N.; Feidenhans`l, R.; Johannsen, I. [eds.

    1999-04-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical properties of materials. The principal activities in the year 1998 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scale structures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au) 2 tabs., 142 ills., 169 refs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R.R. (comp.)

    1981-05-01

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

  2. NWChem: Quantum Chemistry Simulations at Scale

    Energy Technology Data Exchange (ETDEWEB)

    Apra, Edoardo; Kowalski, Karol; Hammond, Jeff R.; Klemm, Michael

    2015-01-17

    Methods based on quantum mechanics equations have been developed since the 1930's with the purpose of accurately studying the electronic structure of molecules. However, it is only during the last two decades that intense development of new computational algorithms has opened the possibility of performing accurate simulations of challenging molecular processes with high-order many-body methods. A wealth of evidence indicates that the proper inclusion of instantaneous interactions between electrons (or the so-called electron correlation effects) is indispensable for the accurate characterization of chemical reactivity, molecular properties, and interactions of light with matter. The availability of reliable methods for benchmarking of medium-size molecular systems provides also a unique chance to propagate high-level accuracy across spatial scales through the multiscale methodologies. Some of these methods have potential to utilize computational resources in an effi*cient way since they are characterized by high numerical complexity and appropriate level of data granularity, which can be effi*ciently distributed over multi-processor architectures. The broad spectrum of coupled cluster (CC) methods falls into this class of methodologies. Several recent CC implementations clearly demonstrated the scalability of CC formalisms on architectures composed of hundreds thousand computational cores. In this context NWChem provides a collection of Tensor Contraction Engine (TCE) generated parallel implementations of various coupled cluster methods capable of taking advantage of many thousand of cores on leadership class parallel architectures.

  3. Chemistry Division. Quarterly progress report for period ending June 30, 1949

    Energy Technology Data Exchange (ETDEWEB)

    1949-09-14

    Progress reports are presented for the following tasks: (1) nuclear and chemical properties of heavy elements (solution chemistry, phase rule studies); (2) nuclear and chemical properties of elements in the fission product region; (3) general nuclear chemistry; (4) radio-organic chemistry; (5) chemistry of separations processes; (6) physical chemistry and chemical physics; (7) radiation chemistry; (8) physical measurements and instrumentation; and (9) analytical chemistry. The program of the chemistry division is divided into two efforts of approximately equal weight with respect to number of personnel, chemical research, and analytical service for the Laboratory. The various research problems fall into the following classifications: (1) chemical separation processes for isolation and recovery of fissionable material, production of radioisotopes, and military applications; (2) reactor development; and (3) fundamental research.

  4. Analytical Chemistry Laboratory. Progress report for FY 1996

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Boparai, A.S.; Bowers, D.L.

    1996-12-01

    The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1996. This annual report is the thirteenth for the ACL. It describes effort on continuing and new projects and contributions of the ACL staff to various programs at ANL. The ACL operates in the ANL system as a full-cost-recovery service center, but has a mission that includes a complementary research and development component: The Analytical Chemistry Laboratory will provide high-quality, cost-effective chemical analysis and related technical support to solve research problems of our clients -- Argonne National Laboratory, the Department of Energy, and others -- and will conduct world-class research and development in analytical chemistry and its applications. Because of the diversity of research and development work at ANL, the ACL handles a wide range of analytical chemistry problems. Some routine or standard analyses are done, but the ACL usually works with commercial laboratories if our clients require high-volume, production-type analyses. It is common for ANL programs to generate unique problems that require significant development of methods and adaption of techniques to obtain useful analytical data. Thus, much of the support work done by the ACL is very similar to our applied analytical chemistry research.

  5. Analytical Chemistry Laboratory progress report for FY 1985

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Heinrich, R.R.; Jensen, K.J.

    1985-12-01

    The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of technical support services to the scientific and engineering programs at ANL. In addition, ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques. The purpose of this report is to summarize the technical and administrative activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1985 (October 1984 through September 1985). This is the second annual report for the ACL. 4 figs., 1 tab.

  6. Analytical Chemistry Laboratory, progress report for FY 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-01

    The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1993 (October 1992 through September 1993). This annual report is the tenth for the ACL and describes continuing effort on projects, work on new projects, and contributions of the ACL staff to various programs at ANL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. The ACL also has research programs in analytical chemistry, conducts instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems. Some routine or standard analyses are done, but it is common for the Argonne programs to generate unique problems that require development or modification of methods and adaption of techniques to obtain useful analytical data. The ACL is administratively within the Chemical Technology Division (CMT), its principal ANL client, but provides technical support for many of the technical divisions and programs at ANL. The ACL has four technical groups--Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis--which together include about 45 technical staff members. Talents and interests of staff members cross the group lines, as do many projects within the ACL.

  7. Analytical Chemistry Laboratory Progress Report for FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Boparai, A.S.; Bowers, D.L. [and others

    1994-12-01

    The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1994 (October 1993 through September 1994). This annual report is the eleventh for the ACL and describes continuing effort on projects, work on new projects, and contributions of the ACL staff to various programs at ANL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. The ACL also has a research program in analytical chemistry, conducts instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems. Some routine or standard analyses are done, but it is common for the Argonne programs to generate unique problems that require significant development of methods and adaption of techniques to obtain useful analytical data. The ACL has four technical groups -- Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis -- which together include about 45 technical staff members. Talents and interests of staff members cross the group lines, as do many projects within the ACL. The Chemical Analysis Group uses wet- chemical and instrumental methods for elemental, compositional, and isotopic determinations in solid, liquid, and gaseous samples and provides specialized analytical services. Major instruments in this group include an ion chromatograph (IC), an inductively coupled plasma/atomic emission spectrometer (ICP/AES), spectrophotometers, mass spectrometers (including gas-analysis and thermal-ionization mass spectrometers), emission spectrographs, autotitrators, sulfur and carbon determinators, and a kinetic phosphorescence uranium analyzer.

  8. Applied physical chemistry progress report, October 1991--September 1992

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, C.E.; Attaya, H.M.; Billone, M.C.; Blomquist, R.A.; Kopasz, J.P.; Leibowitz, L.; Roche, M.F.; Seils, C.A.

    1993-12-01

    This document reports on the work done in applied physical chemistry at the Chemical Technology Division (CMT), Argonne National Laboratory (ANL), in the period October 1991 through September 1992. this work includes research into the process that control the release and transport of fission products under accident-like conditions in a light water reactor, the thermophysical properties of the metal fuel in the Integral Fast Reactor under development at ANL, and the properties of candidate tritium breeding materials in environments simulating those of fusion energy systems. Viscosity and liquidus-solidus temperatures of core-concrete mixtures were studied.

  9. Analytical Chemistry Division annual progress report for period ending December 31, 1985

    Energy Technology Data Exchange (ETDEWEB)

    Shultz, W.D.

    1986-05-01

    Progress reports are presented for the four major sections of the division: analytical spectroscopy, radioactive materials laboratories, inorganic chemistry, and organic chemistry. A brief discussion of the division's role in the Laboratory's Environmental Restoration and Facilities Upgrade is given. Information about quality assurance and safety programs is presented, along with a tabulation of analyses rendered. Publications, oral presentations, professional activities, educational programs, and seminars are cited.

  10. Polyphenolic chemistry of tea and coffee: a century of progress.

    Science.gov (United States)

    Wang, Yu; Ho, Chi-Tang

    2009-09-23

    Tea and coffee, the most popular beverages in the world, have been consumed for thousands of years for their alluring flavors and health benefits. Polyphenols, particularly flavonoids and phenolic acids, are of great abundance in tea and coffee and contribute a lot to their flavor and health properties. This paper reviews the polyphenol chemistry of tea and coffee, specifically their stability, and scavenging ability of reactive oxygen species (ROS) and reactive carbonyl species (RCS). During the manufacturing and brewing process, green tea and black tea polyphenols undergo epimerization and oxidation, respectively. Meanwhile, the lactonization and the polymerization of chlorogenic acid are the major causes for the degradation of polyphenols in coffee. Tea catechins, besides having antioxidant properties, have the novel characteristic of trapping reactive carbonyl species. The A ring of the catechins is the binding site for RCS trapping, whereas the B ring is the preferred site for antioxidation.

  11. Progress in the Chemistry of Naturally Occurring Coumarins.

    Science.gov (United States)

    Sarker, Satyajit D; Nahar, Lutfun

    Coumarins are the largest group of 1-benzopyran derivatives found in plants. The initial member of this group of compounds, coumarin (2H-1-benzopyran-2-one), a fragrant colorless compound, was first isolated from the Tonka bean (Dipteryx odorata, family Fabaceae) in 1820. The name coumarin comes from a French term for the tonka bean, coumarou. Since the discovery of coumarin, several of its derivatives, with umbelliferone (7-hydroxycoumarin) being the most common one, have been reported from various natural sources. The families Apiaceae, Asteraceae, and Rutaceae are the three major plant sources of coumarins.Generally, these plant secondary metabolites may be classified into simple, simple prenylated, simple geranylated, furano, pyrano, sesquiterpenyl and oligomeric coumarins. Using this standard classification, this chapter aims to present an account on the advances of the chemistry of naturally occurring coumarins, as reported in the literature during the period 2013-2015.In Sect. 1, the coumarins are introduced and their generic biosynthetic route discussed briefly. In Sect. 2, the largest of the three sections, various classes of natural coumarins are detailed, with their relevant structures and the citation of appropriate references. In a concluding section, it is highlighted that during the last 3 years, more than 400 coumarins have been reported in the literature. Many of these coumarins have been re-isolations of known compounds from known or new sources, most often associated with various biological activities. However, a substantial number of coumarins bearing new skeletons, especially dimers, prenylated furanocoumarins, sesquiterpenyl, and some unusual coumarins were also reported during the period of 2013-2015.Coumarin chemistry remains one of the major interest areas of phytochemists, especially because of their structural diversity and medicinal properties, along with the wide-ranging bioactivities of these compounds, inclusive of analgesic

  12. Racing chemistry: A century of challenges and progress.

    Science.gov (United States)

    Kremmer, Christopher

    2017-09-01

    Horseracing has been called 'one of the first quintessentially modern sports'. Its urge towards standardization, its mathematically set odds, its concern with weights, and its pioneering embrace of drug-testing reflect an empirical temperament crucial to its transformation from a gentleman's pastime to a global industry funded by wagering. Ironically, in the late nineteenth century, it was modern science itself, and in particular the purification and synthesis of the drugs of nature, that turned the doping of racing animals - a practice recorded in antiquity - into an organized criminal enterprise. This paper presents original research into the history of racing chemistry in Australia in the context of developments in the field worldwide. Using a case-study approach based on extensive archival materials, it reveals unpublished diaries kept by an analyst working at Sydney Racing Laboratory in the 1950s that document conflicts between scientists over identification of performance drugs in racing animals. The author presents evidence that augments and revises earlier narratives concerning the history of the establishment of laboratory control at Australian racetracks and the removal of the country's first official analyst for racing, Miss Jean Kimble. The Kimble case illustrates the inevitable political, professional, and personal pressures that bear upon drug-testing in sports, and also conflicts between scientists over standards and priorities. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  13. IPEN's Nuclear Physics and Chemistry Department - Progress report - 1995-1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The biannual progress report of 1995-1996 of IPEN's Nuclear Physics and Chemistry Department - Brazilian organization - introduces the next main topics: neutron activation and radiochemical analysis; nuclear structure and reactions; neutron diffraction; hyperfine interactions; applied physics and instrumentation; publications; academic activities; services; and personnel.

  14. Chemistry research and development. Progress report, July 1977--May 1978

    Energy Technology Data Exchange (ETDEWEB)

    Miner, F.J.

    1979-03-30

    Studies were continued to determine the compatibility of non-nuclear weapons metals with various production processing materials. The corrosion resistance of 304L stainless steel in mixed acid environment was tested. Intergranular corrosion tests were performed on welded 21-6-9 and 304L stainless steels. A laboratory scale fast fluidized bed incineration system was installed and operating techniques developed. A new uranium chip burning process is being developed. Component development, pilot plant development, and instrumentation and statistical systems development are briefly discussed.

  15. Flow Chemistry on Multigram Scale: Continuous Synthesis of Boronic Acids within 1 s.

    Science.gov (United States)

    Hafner, Andreas; Meisenbach, Mark; Sedelmeier, Joerg

    2016-08-05

    The benefits and limitations of a simple continuous flow setup for handling and performing of organolithium chemistry on the multigram scale is described. The developed metalation platform embodies a valuable complement to existing methodologies, as it combines the benefits of Flash Chemistry (chemical synthesis on a time scale of <1 s) with remarkable throughput (g/min) while mitigating the risk of blockages.

  16. Annual progress report of the Condensed Matter Physics and Chemistry Department. 1 January - 31 December 1999

    Energy Technology Data Exchange (ETDEWEB)

    Lebech, B. [ed.

    2000-02-01

    The Condensed Matter Physics and Chemistry Department is concerned with both fundamental and applied research into the physical and chemical properties of materials. The principal activities in the year 1999 are presented in this progress report. The research in physics is concentrated on neutron and x-ray scattering measurements and the problems studied include two- and three-dimensional structures, magnetic ordering and spin dynamics, superconductivity, phase transitions and nano-scalestructures. The research in chemistry includes chemical synthesis and physico-chemical investigation of small molecules and polymers, with emphasis on polymers with new optical properties, block copolymers, surface-modified polymers, and supramolecular structures. Theoretical work related to these problems is undertaken, including Monte Carlo simulations, computer simulation of molecules and polymers and methods of data analysis. (au)

  17. Current organic chemistry

    National Research Council Canada - National Science Library

    1997-01-01

    Provides in depth reviews on current progress in the fields of asymmetric synthesis, organometallic chemistry, bioorganic chemistry, heterocyclic chemistry, natural product chemistry, and analytical...

  18. Chemistry Division annual progress report for period ending July 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    Research is reported on: chemistry of coal liquefaction, aqueous chemistry at high temperatures, geosciences, high-temperature chemistry and thermodynamics of structural materials, chemistry of TRU elements and compounds, separations chemistry, electrochemistry, nuclear waste chemistry, chemical physics, theoretical chemistry, inorganic chemistry of hydrogen cycles, molten salt systems, and enhanced oil recovery. Separate abstracts were prepared for the sections dealing with coal liquefaction, TRU elements and compounds, separations, nuclear wastes, and enhanced oil recovery. (DLC)

  19. Chemistry Division annual progress report for period ending January 31, 1986

    Energy Technology Data Exchange (ETDEWEB)

    1986-05-01

    This report has been indexed by 11 separate chapters. The subjects covered are: coal chemistry, aqueous chemistry at high temperatures and pressures, geochemistry, materials chemistry, chemistry of transuranium elements and compounds, separations chemistry, catalysis, electron spectroscopy, nuclear waste chemistry, heuristic modeling, and special topics. (PLG)

  20. small-scale chemistry for a hands-on approach to chemistry practical

    African Journals Online (AJOL)

    IICBA01

    Department of Chemistry, Norwegian University of Science and Technology, NTNU, Norway .... implemented as of 2008, 70% of the student enrolment in universities (and secondary schools alike) has to be in the ..... friendly, and both they and their students were smiling, signs of their motivation and happiness.

  1. 25th anniversary article: progress in chemistry and applications of functional indigos for organic electronics.

    Science.gov (United States)

    Głowacki, Eric Daniel; Voss, Gundula; Sariciftci, Niyazi Serdar

    2013-12-17

    Indigo and its derivatives are dyes and pigments with a long and distinguished history in organic chemistry. Recently, applications of this 'old' structure as a functional organic building block for organic electronics applications have renewed interest in these molecules and their remarkable chemical and physical properties. Natural-origin indigos have been processed in fully bio-compatible field effect transistors, operating with ambipolar mobilities up to 0.5 cm(2) /Vs and air-stability. The synthetic derivative isoindigo has emerged as one of the most successful building-blocks for semiconducting polymers for plastic solar cells with efficiencies > 5%. Another isomer of indigo, epindolidione, has also been shown to be one of the best reported organic transistor materials in terms of mobility (∼2 cm(2) /Vs) and stability. This progress report aims to review very recent applications of indigoids in organic electronics, but especially to logically bridge together the hereto independent research directions on indigo, isoindigo, and other materials inspired by historical dye chemistry: a field which was the root of the development of modern chemistry in the first place. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Current progress on the chemical functionalization and supramolecular chemistry of M@C82

    Science.gov (United States)

    Maeda, Yutaka; Tsuchiya, Takahiro; Lu, Xing; Takano, Yuta; Akasaka, Takeshi; Nagase, Shigeru

    2011-06-01

    Since the first discovery of fullerenes in 1985, the insertion of one or more atoms into a hollow fullerene cage has been attempted. Furthermore, synthesis and extraction of metallofullerene, La@Cn, were reported in 1991. Recent successful isolation and purification of metallofullerenes have facilitated the investigation of their chemical properties. This mini-review presents a summary of the recent progress of chemical functionalization and supramolecular chemistry of M@C82. Selective functionalization and successful structural analysis of derivatives have revealed their chemical features arising from endohedral metal doping.Since the first discovery of fullerenes in 1985, the insertion of one or more atoms into a hollow fullerene cage has been attempted. Furthermore, synthesis and extraction of metallofullerene, La@Cn, were reported in 1991. Recent successful isolation and purification of metallofullerenes have facilitated the investigation of their chemical properties. This mini-review presents a summary of the recent progress of chemical functionalization and supramolecular chemistry of M@C82. Selective functionalization and successful structural analysis of derivatives have revealed their chemical features arising from endohedral metal doping. This article was submitted as part of a collection highlighting papers from the Fullerene Silver Anniversary Symposium Conference held in Crete in October 2010.

  3. Impact of General Chemistry on Student Achievement and Progression to Subsequent Chemistry Courses: A Regression Discontinuity Analysis

    Science.gov (United States)

    Shultz, Ginger V.; Gottfried, Amy C.; Winschel, Grace A.

    2015-01-01

    General chemistry is a gateway course that impacts the STEM trajectory of tens of thousands of students each year, and its role in the introductory curriculum as well as its pedagogical design are the center of an ongoing debate. To investigate the role of general chemistry in the curriculum, we report the results of a posthoc analysis of 10 years…

  4. Chemistry Division: Annual progress report for period ending March 31, 1987

    Energy Technology Data Exchange (ETDEWEB)

    1987-08-01

    This report is divided into the following sections: coal chemistry; aqueous chemistry at high temperatures and pressures; geochemistry of crustal processes to high temperatures and pressures; chemistry of advanced inorganic materials; structure and dynamics of advanced polymeric materials; chemistry of transuranium elements and compounds; separations chemistry; reactions and catalysis in molten salts; surface science related to heterogeneous catalysis; electron spectroscopy; chemistry related to nuclear waste disposal; computational modeling of security document printing; and special topics. (DLC)

  5. Chemistry of the pheromones of mealybug and scale insects.

    Science.gov (United States)

    Zou, Yunfan; Millar, Jocelyn G

    2015-07-01

    This article comprehensively reviews the syntheses of all known sex pheromones of scales and mealybugs, describes how they were identified, and how the synthetic pheromones are used in insect management.

  6. Analytical Chemistry Division annual progress report for period ending December 31, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1988-05-01

    The Analytical Chemistry Division of Oak Ridge National Laboratory (ORNL) is a large and diversified organization. As such, it serves a multitude of functions for a clientele that exists both in and outside of ORNL. These functions fall into the following general categories: (1) Analytical Research, Development, and Implementation. The division maintains a program to conceptualize, investigate, develop, assess, improve, and implement advanced technology for chemical and physicochemical measurements. Emphasis is on problems and needs identified with ORNL and Department of Energy (DOE) programs; however, attention is also given to advancing the analytical sciences themselves. (2) Programmatic Research, Development, and Utilization. The division carries out a wide variety of chemical work that typically involves analytical research and/or development plus the utilization of analytical capabilities to expedite programmatic interests. (3) Technical Support. The division performs chemical and physicochemical analyses of virtually all types. The Analytical Chemistry Division is organized into four major sections, each of which may carry out any of the three types of work mentioned above. Chapters 1 through 4 of this report highlight progress within the four sections during the period January 1 to December 31, 1988. A brief discussion of the division's role in an especially important environmental program is given in Chapter 5. Information about quality assurance, safety, and training programs is presented in Chapter 6, along with a tabulation of analyses rendered. Publications, oral presentations, professional activities, educational programs, and seminars are cited in Chapters 7 and 8.

  7. Analytical Chemistry Division annual progress report for period ending December 31, 1989

    Energy Technology Data Exchange (ETDEWEB)

    1990-04-01

    The Analytical Chemistry Division of Oak Ridge National Laboratory (ORNL) is a large and diversified organization. As such, it serves a multitude of functions for a clientele that exists both in and outside of ORNL. These functions fall into the following general categories: Analytical Research, Development and Implementation; Programmatic Research, Development, and Utilization; and Technical Support. The Analytical Chemistry Division is organized into four major sections, each which may carry out any of the three types of work mentioned above. Chapters 1 through 4 of this report highlight progress within the four sections during the period January 1 to December 31, 1989. A brief discussion of the division's role in an especially important environmental program is given in Chapter 5. Information about quality assurance, safety, and training programs is presented in Chapter 6, along with a tabulation of analyses rendered. Publications, oral presentations, professional activities, educational programs, and seminars are cited in Chapters 7 and 8. Approximately 69 articles, 41 proceedings, and 31 reports were published, and 151 oral presentations were given during this reporting period. Some 308,981 determinations were performed.

  8. Analytical Chemistry Division. Annual progress report for period ending December 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, W. S. [ed.

    1982-04-01

    The functions of the Analytical Chemistry Division fall into three general categories: (1) analytical research, development, and implementation; (2) programmatic research, development and utilization; (3) technical support. The Division is organized into five major sections each of which may carry out any type of work falling into the thre categories mentioned above. Chapters 1 through 5 of this report highlight progress within the five sections which are: analytical methodology; mass and emission spectrometry; analytical technical support; bio/organic analysis section; and nuclear and radiochemical analysis. A short summary introduces each chapter to indicate work scope. Information about quality assurance and safety programs is presented in Chapter 6, along with a tabulation of analyses rendered. Chapter 7 covers supplementary activities. Chapter 8 is on presentation of research results (publications, articles reviewed or referred for periodicals). Approximately 56 articles, 31 proceedings publications and 33 reports have been published, and 119 oral presentations given during this reporting period.

  9. Climate and chemistry effects of a regional scale nuclear conflict

    Directory of Open Access Journals (Sweden)

    A. Stenke

    2013-10-01

    Full Text Available Previous studies have highlighted the severity of detrimental effects for life on earth after an assumed regionally limited nuclear war. These effects are caused by climatic, chemical and radiative changes persisting for up to one decade. However, so far only a very limited number of climate model simulations have been performed, giving rise to the question how realistic previous computations have been. This study uses the coupled chemistry climate model (CCM SOCOL, which belongs to a different family of CCMs than previously used, to investigate the consequences of such a hypothetical nuclear conflict. In accordance with previous studies, the present work assumes a scenario of a nuclear conflict between India and Pakistan, each applying 50 warheads with an individual blasting power of 15 kt ("Hiroshima size" against the major population centers, resulting in the emission of tiny soot particles, which are generated in the firestorms expected in the aftermath of the detonations. Substantial uncertainties related to the calculation of likely soot emissions, particularly concerning assumptions of target fuel loading and targeting of weapons, have been addressed by simulating several scenarios, with soot emissions ranging from 1 to 12 Tg. Their high absorptivity with respect to solar radiation leads to a rapid self-lofting of the soot particles into the strato- and mesosphere within a few days after emission, where they remain for several years. Consequently, the model suggests earth's surface temperatures to drop by several degrees Celsius due to the shielding of solar irradiance by the soot, indicating a major global cooling. In addition, there is a substantial reduction of precipitation lasting 5 to 10 yr after the conflict, depending on the magnitude of the initial soot release. Extreme cold spells associated with an increase in sea ice formation are found during Northern Hemisphere winter, which expose the continental land masses of North

  10. New prospects of low-scale gas chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Arutyunov, Vladimir, E-mail: arutyunov@center.chph.ras.ru [Semenov Institute of Chemical Physics, Russ. Acad. Sci., Kosygina, 4, Moscow, 119991 (Russian Federation)

    2011-04-01

    The large-scale industrial sources of conventional natural gas are limited and can be exhausted in the nearest future. But there are still a significant number of low deposit, remote, low-pressure fields, and abundant resources of unconventional gas including coal-bed methane, shale gas, gas hydrates. However, usually these sources are less intensive, short living and spread through a large area. So gas industry very likely will have to develop new low-scale technologies to explore and process such resources into more valuable and easily transportable liquid products to satisfy consumers in any point of the world as we do it now with oil and petrochemicals.

  11. Electrostimulation to reduce synaptic scaling driven progression of Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Mark eRowan

    2014-04-01

    Full Text Available Cell death and synapse dysfunction are two likely causes of cognitive decline in AD. As cells die and synapses lose their drive, remaining cells suffer an initial decrease in activity. Neuronal homeostatic synaptic scaling then provides a feedback mechanism to restore activity. This homeostatic mechanism is believed to sense levels of activity-dependent cytosolic calcium within the cell and to adjust neuronal firing activity by increasing the density of AMPA synapses at remaining synapses to achieve balance. The scaling mechanism increases the firing rates of remaining cells in the network to compensate for decreases in network activity. However, this effect can itself become a pathology, as it produces increased imbalance between excitatory and inhibitory circuits, leading to greater susceptibility to further cell loss via calcium-mediated excitotoxicity.Here, we present a mechanistic explanation of how directed brain stimulation might be expected to slow AD progression based on computational simulations in a 470-neuron biomimetic model of a neocortical column. The simulations demonstrate that the addition of low-intensity electrostimulation (neuroprosthesis to a network undergoing AD-like cell death can raise global activity and break this homeostatic-excitotoxic cascade. The increase in activity within the remaining cells in the column results in lower scaling-driven AMPAR upregulation, reduced imbalances in excitatory and inhibitory circuits, and lower susceptibility to ongoing damage.

  12. The self-evaluation of Slovenian prospective chemistry teachers' progress during their practical pedagogical training in primary schools.

    Science.gov (United States)

    Wissiak Grm, Katarina S; Savec, Vesna Ferk

    2014-01-01

    The present research deals with the self-evaluation of prospective chemistry teachers' progress during their practical pedagogical training (PPT) in primary schools. The sample consisted of 42 students from the 3rd and 4th years of the undergraduate programmes "Chemistry and Biology" or "Chemistry and Physics" at the Faculty of Education, University of Ljubljana. For the purpose of the investigation, the students completed questionnaires after each day of their practical pedagogical training, and at the end the entire training wrote reflective essays about their most significant experiences. Analysis of the results reveals that the students believe that practical pedagogical training makes a crucial contribution to their practical pedagogical education in the light of their future profession. The students also reported on their progress concerning the various skills that were developed.

  13. Solution chemistry and scaling in hot dry rock geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    Tester, J.W.; Holley, C.E. Jr.; Blatz, L.A.

    1977-01-01

    Field and laboratory experiments have focused on measuring the kinetics and equilibria associated with the transport of minerals from granite to circulating aqueous solutions. Presently two wellbores drilled to a depth of approximately 10,000 ft in the Valles Caldera region of the New Mexico Jemez mountains permit closed-loop circulation of fluid through a hydraulically fractured granite geothermal reservoir containing rock at 200/sup 0/C. Field measurements have dealth primarily with the buildup of dissolved and suspended material in water as it is circulated through the fractured region. Chemical treatment methods, involving the selective dissolution of quartz (SiO/sub 2/), a major component of granite, with sodium carbonate solutions have been employed to increase the in situ permeability of the rock matrix. Laboratory measurements have concentrated on identifying the effects of temperature, pH and chemical additives on the solubility of granite samples taken from the two test wellbores. Promising results from these solubility experiments are tested in a laboratory-scale circulating system to examine kinetic parameters influencing rock dissolution and reprecipitation (scaling) under conditions that simulate the in situ reservoir and heat exchange environments.

  14. Chemistry?!

    Indian Academy of Sciences (India)

    Chemistry is the science of matter and of its transformations, and life is its highest expression. It provides structures endowed with properties and develops processes for the synthesis of structures. It plays a primordial role in our understanding of material phe- nomena, in our capability to act upon them, to modify them, to.

  15. Analytical Chemistry Division annual progress report for period ending December 31, 1991

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-01-01

    The following sentences highlight some of the technical activities carried out during 1991. They illustrate the diversity of programs and technical work performed within the Analytical Chemistry Division. Our neutron activation analysis laboratory at HFIR was placed into operation during 1991. We have combined inductively coupled plasma mass spectrometry (ICP/MS) with a preparation procedure developed at the Argonne National Laboratory to measure ultra-trace levels of U, Pu, Np, and Am in body fluids, primarily urine. Much progress has been made over the last year in the interfacing of an rf-powered glow discharge source to a double-focusing mass spectrometer. Preliminary experiments using electrospray ionization combined with ion trap mass spectrometry show much promise for the analysis of metals in solution. A secondary ion microprobe has been constructed that permits determination of the distribution of organic compounds less than a monolayer thick on samples as large as 1 cm diameter. Fourier transform mass spectrometry has been demonstrated to be a highly effective tool for the detailed characterization of biopolymers, especially normal and modified oligonucleotides. Much has been accomplished in understanding the fundamentals of quadrupole ion trap mass spectrometry. Work with ITMS instrumentation has led to the development of rapid methods for the detection of trace organics in environmental and physiological samples. A new type of time-of-flight mass spectrometer was designed for use with our positron ionization experiments. Fundamental research on chromatography at high concentrations and on gas-solid adsorption has continued. The preparation of a monograph on the chemistry of environmental tobacco smoke was completed this year.

  16. Fine scale variations of surface water chemistry in an ephemeral to perennial drainage network

    Science.gov (United States)

    Margaret A. Zimmer; Scott W. Bailey; Kevin J. McGuire; Thomas D. Bullen

    2013-01-01

    Although temporal variation in headwater stream chemistry has long been used to document baseline conditions and response to environmental drivers, less attention is paid to fine scale spatial variations that could yield clues to processes controlling stream water sources. We documented spatial and temporal variation in water composition in a headwater catchment (41 ha...

  17. Phase II -- Photovoltaics for Utility Scale Applications (PVUSA). Progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale (US) photovoltaic (PV) electric generation systems and recent developments in PV module technology. This report updates the project`s progress, reviews the status and performance of the various PV installations during 1994, summarizes key accomplishments and conclusions for the year, and outlines future work. The PVUSA project has five objectives. These are designed to narrow the gap between a large utility industry that is unfamiliar with PV and a small PV industry that is aware of a potentially large utility market but unfamiliar with how to meet its requirements. The objectives are: Evaluate the performance, reliability, and cost of promising PV modules and balance-of-system (BOS) components side by side at a single location; Assess PV system operation and maintenance in a utility setting; Compare US utilities hands-on experience in designing, procuring, and operating PV systems; and, Document and disseminate knowledge gained from the project.

  18. Analytical Chemistry Division annual progress report: For period ending December 31, 1987

    Energy Technology Data Exchange (ETDEWEB)

    1988-05-01

    This report is divided into analytical spectroscopy; radioactive materials analysis; inorganic chemistry; organic chemistry; ORNL environmental programs; quality assurance, safety, and training; supplementary activities; and presentation of research results.

  19. Developing Technical Writing Skills in the Physical Chemistry Laboratory: A Progressive Approach Employing Peer Review

    Science.gov (United States)

    Gragson, Derek E.; Hagen, John P.

    2010-01-01

    Writing formal "journal-style" lab reports is often one of the requirements chemistry and biochemistry students encounter in the physical chemistry laboratory. Helping students improve their technical writing skills is the primary reason this type of writing is a requirement in the physical chemistry laboratory. Developing these skills is an…

  20. Chemistry Division annual progress report for period ending April 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Poutsma, M.L.; Ferris, L.M.; Mesmer, R.E.

    1993-08-01

    The Chemistry Division conducts basic and applied chemical research on projects important to DOE`s missions in sciences, energy technologies, advanced materials, and waste management/environmental restoration; it also conducts complementary research for other sponsors. The research are arranged according to: coal chemistry, aqueous chemistry at high temperatures and pressures, geochemistry, chemistry of advanced inorganic materials, structure and dynamics of advanced polymeric materials, chemistry of transuranium elements and compounds, chemical and structural principles in solvent extraction, surface science related to heterogeneous catalysis, photolytic transformations of hazardous organics, DNA sequencing and mapping, and special topics.

  1. Analytical Chemistry Division annual progress report for period ending December 31, 1982

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, W.S. (ed.)

    1983-05-01

    The Analytical Chemistry Dvision of Oak Ridge National laboratory (ORNL) serves a multitude of functions for a clientele that exists both in and outside ORNL. These functions fall into the following general categories: (1) analytical research, development, and implementation; (2) programmatic research, development, and utilization; and (3) technical support. The Division is organized into five major sections, each of which may carry out any type of work falling in the three categories mentioned above. Chapters 1 through 5 of this report highlight progress within the five sections (analytical methodology, mass and emission spectrometry, radioactive materials, bio/organic analysis, and general and environmental analysis) during the period January 1, 1982 to December 31, 1982. A short summary introduces each chapter to indicate work scope. Information about quality assurance and safety programs is presented in Chapter 6, along with a tabulation of analyses rendered. Publications, oral presentations, professional activities, educational programs, and seminars are cited in Chapters 7 and 8. Approximately 61 articles, 32 proceedings publications and 37 reports have been published, and 107 oral presentations were given during this reporting period.

  2. Development and Validation of Chemistry Self-Efficacy Scale for College Students

    Science.gov (United States)

    Uzuntiryaki, Esen; Çapa Aydın, Yeşim

    2009-08-01

    This study described the process of developing and validating the College Chemistry Self-Efficacy Scale (CCSS) that can be used to assess college students’ beliefs in their ability to perform essential tasks in chemistry. In the first phase, data collected from 363 college students provided evidence for the validity and reliability of the new scale. Three dimensions emerged: self-efficacy for cognitive skills, self-efficacy for psychomotor skills, and self-efficacy for everyday applications. In the second phase, data collected from an independent sample of 353 college students confirmed the factorial structure of the 21-item CCSS. The Cronbach alpha coefficients ranged from 0.82 to 0.92. In addition, each dimension of the CCSS had moderate and significant correlations with student chemistry achievement and differentiated between major and non-major students. Followed by the additional validation studies, the CCSS will serve as a valuable tool for both instructors and researchers in science education to assess college students’ chemistry self-efficacy beliefs.

  3. Chemistry {ampersand} Materials Science progress report summary of selected research and development topics, FY97

    Energy Technology Data Exchange (ETDEWEB)

    Newkirk, L.

    1997-12-01

    This report contains summaries of research performed in the Chemistry and Materials Science division. Topics include Metals and Ceramics, High Explosives, Organic Synthesis, Instrument Development, and other topics.

  4. Analytical Chemistry Division annual progress report for period ending December 31, 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-04-01

    The Analytical Chemistry Division has programs in inorganic mass spectrometry, optical spectroscopy, organic mass spectrometry, and secondary ion mass spectrometry. It maintains a transuranium analytical laboratory and an environmental analytical laboratory. It carries out chemical and physical analysis in the fields of inorganic chemistry, organic spectroscopy, separations and synthesis. (WET)

  5. Student Conceptions about Energy Transformations: Progression from General Chemistry to Biochemistry

    Science.gov (United States)

    Wolfson, Adele J.; Rowland, Susan L.; Lawrie, Gwendolyn A.; Wright, Anthony H.

    2014-01-01

    Students commencing studies in biochemistry must transfer and build on concepts they learned in chemistry and biology classes. It is well established, however, that students have difficulties in transferring critical concepts from general chemistry courses; one key concept is "energy." Most previous work on students' conception of energy…

  6. Workshop report on large-scale matrix diagonalization methods in chemistry theory institute

    Energy Technology Data Exchange (ETDEWEB)

    Bischof, C.H.; Shepard, R.L.; Huss-Lederman, S. [eds.

    1996-10-01

    The Large-Scale Matrix Diagonalization Methods in Chemistry theory institute brought together 41 computational chemists and numerical analysts. The goal was to understand the needs of the computational chemistry community in problems that utilize matrix diagonalization techniques. This was accomplished by reviewing the current state of the art and looking toward future directions in matrix diagonalization techniques. This institute occurred about 20 years after a related meeting of similar size. During those 20 years the Davidson method continued to dominate the problem of finding a few extremal eigenvalues for many computational chemistry problems. Work on non-diagonally dominant and non-Hermitian problems as well as parallel computing has also brought new methods to bear. The changes and similarities in problems and methods over the past two decades offered an interesting viewpoint for the success in this area. One important area covered by the talks was overviews of the source and nature of the chemistry problems. The numerical analysts were uniformly grateful for the efforts to convey a better understanding of the problems and issues faced in computational chemistry. An important outcome was an understanding of the wide range of eigenproblems encountered in computational chemistry. The workshop covered problems involving self- consistent-field (SCF), configuration interaction (CI), intramolecular vibrational relaxation (IVR), and scattering problems. In atomic structure calculations using the Hartree-Fock method (SCF), the symmetric matrices can range from order hundreds to thousands. These matrices often include large clusters of eigenvalues which can be as much as 25% of the spectrum. However, if Cl methods are also used, the matrix size can be between 10{sup 4} and 10{sup 9} where only one or a few extremal eigenvalues and eigenvectors are needed. Working with very large matrices has lead to the development of

  7. Net Community Metabolism and Seawater Carbonate Chemistry Scale Non-intuitively with Coral Cover

    Directory of Open Access Journals (Sweden)

    Heather N. Page

    2017-05-01

    Full Text Available Coral cover and reef health have been declining globally as reefs face local and global stressors including higher temperature and ocean acidification (OA. Ocean warming and acidification will alter rates of benthic reef metabolism (i.e., primary production, respiration, calcification, and CaCO3 dissolution, but our understanding of community and ecosystem level responses is limited in terms of functional, spatial, and temporal scales. Furthermore, dramatic changes in coral cover and benthic metabolism could alter seawater carbonate chemistry on coral reefs, locally alleviating or exacerbating OA. This study examines how benthic metabolic rates scale with changing coral cover (0–100%, and the subsequent influence of these coral communities on seawater carbonate chemistry based on mesocosm experiments in Bermuda and Hawaii. In Bermuda, no significant differences in benthic metabolism or seawater carbonate chemistry were observed for low (40% and high (80% coral cover due to large variability within treatments. In contrast, significant differences were detected between treatments in Hawaii with benthic metabolic rates increasing with increasing coral cover. Observed increases in daily net community calcification and nighttime net respiration scaled proportionally with coral cover. This was not true for daytime net community organic carbon production rates, which increased the most between 0 and 20% coral cover and then less so between 20 and 100%. Consequently, diel variability in seawater carbonate chemistry increased with increasing coral cover, but absolute values of pH, Ωa, and pCO2 were not significantly different during daytime. To place the results of the mesocosm experiments into a broader context, in situ seawater carbon dioxide (CO2 at three reef sites in Bermuda and Hawaii were also evaluated; reefs with higher coral cover experienced a greater range of diel CO2 levels, complementing the mesocosm results. The results from this study

  8. Effects of flow and water chemistry on lead release rates from pipe scales.

    Science.gov (United States)

    Xie, Yanjiao; Giammar, Daniel E

    2011-12-01

    Lead release from pipe scales was investigated under different water compositions, stagnation times, and flow regimes. Pipe scales containing PbO(2) and hydrocerussite (Pb(3)(OH)(2)(CO(3))(2)) were developed on lead pipes by conditioning the pipes with water containing free chlorine for eight months. Water chemistry and the composition of the pipe scales are two key factors affecting lead release from pipe scales. The water rarely reached equilibrium with pipe scales within one day, which makes solid-water contact time and corrosion product dissolution rates the controlling factors of lead concentrations for the conditions tested. Among five water compositions studied, a solution with orthophosphate had the lowest dissolved lead release rate and highest particulate lead release rate. Free chlorine also decreased the dissolved lead release rate at stagnant conditions. Water flow increased rates of release of both dissolved and particulate lead by accelerating the mass transfer of lead out of the porous pipe scales and by physically destabilizing pipe scales. Dissolved lead comprised the majority of the lead released at both stagnant and laminar flow conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Development of a MELCOR Sodium Chemistry (NAC) Package - FY17 Progress.

    Energy Technology Data Exchange (ETDEWEB)

    Louie, David; Humphries, Larry L.

    2018-02-01

    This report describes the status of the development of MELCOR S odium Chemistry (NAC) package. This development is based on the CONTAIN-LMR so dium physics and chemistry models to be implemented in MELCOR. In the past three years, the sodium equation of state as a working fluid from the nuclear fu sion safety research and from the SIMMER code has been implemented into MELCOR. The chem istry models from the CONTAIN-LMR code, such as the spray and pool fire mode ls, have also been implemented into MELCOR. This report describes the implemented models and the issues encountered. Model desc riptions and input descriptions are provided. Development testing of the spray and pool fire models is descri bed, including the code- to-code comparison with CONTAIN-LMR. The report ends with an e xpected timeline for the remaining models to be implemented, such as the atmosph ere chemistry, sodium-concrete interactions, and experimental validation tests .

  10. Progress in the medicinal chemistry of silicon: C/Si exchange and beyond.

    Science.gov (United States)

    Fujii, Shinya; Hashimoto, Yuichi

    2017-04-01

    Application of silyl functionalities is one of the most promising strategies among various 'elements chemistry' approaches for the development of novel and distinctive drug candidates. Replacement of one or more carbon atoms of various biologically active compounds with silicon (so-called sila-substitution) has been intensively studied for decades, and is often effective for alteration of activity profile and improvement of metabolic profile. In addition to simple C/Si exchange, several novel approaches for utilizing silicon in medicinal chemistry have been suggested in recent years, focusing on the intrinsic differences between silicon and carbon. Sila-substitution offers great potential for enlarging the chemical space of medicinal chemistry, and provides many options for structural development of drug candidates.

  11. Supported organometallic complexes: Surface chemistry, spectroscopy, and catalysis. Progress report, July 15, 1989--July 14, 1990

    Energy Technology Data Exchange (ETDEWEB)

    Marks, T.J.

    1991-02-01

    Adsorbing organometallic molecules onto the surfaces of inorganic supports such as Al{sub 2}O{sub 3}, MgCl{sub 2}, SiO{sub 2}, etc. can result in dramatic enhancements in catalytic activity. The reasons for this and the structures of the resulting surface organometallic centers are not well understood. We have addressed this problem using thorium, uranium, and early transition metal complexes as model adsorbates. Characterization tools include catalytic and stoichiometric reaction chemistry, reaction kinetics and isotopic labeling, quantitative poisoning studies, model solution chemistry, and a wide array of surface-sensitive physicochemical techniques such as CPMAS, NMR, EPR, and optical spectroscopy as well as titration calorimetry.

  12. Supported organometallic complexes, surface chemistry, spectroscopy, and catalysis. Progress report, September 15, 1992--November 14, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Marks, T.J.

    1993-04-01

    Goal is to elucidate and understand the surface chemistry and catalytic properties of well-defined, highly-reactive organometallic molecules (principally based upon abundant actinide, lanthanide, and early transition elements) adsorbed on metal oxides and halides. Nature of adsorbed species is probed by a battery of chemical and physicochemical techniques, to understand the nature of the molecule-surface coordination chemistry and how this can give rise to extremely high catalytic activity. A complementary objective is to delineate the scope and mechanisms of the heterogeneous catalytic reactions, as well as to relate them both conceptually and functionally to model systems generated in solution.

  13. Supported organometallic complexes: Surface chemistry, spectroscopy, and catalysis. Progress report, February 1, 1991--January 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Marks, T.J.

    1992-02-01

    The long-range goal of this project is to elucidate and understand the surface chemistry and catalytic properties of well-defined, highly-reactive organometallic molecules (principally based upon abundant actinide, lanthanide, and early transition elements) adsorbed on metal oxides and halides. The nature of the adsorbed species is probed by a battery of chemical and physicochemical techniques, to understand the nature of the molecular-surface coordination chemistry and how this can give rise to extremely high catalytic activity. A complementary objective is to delineate the scope and mechanisms of the heterogeneous catalytic reactions, as well as to relate them both conceptually and functionally to model systems generated in solution.

  14. Organometallic chemistry of bimetallic compounds. Progress report, January 1992--July 1995

    Energy Technology Data Exchange (ETDEWEB)

    Casey, C.P.

    1994-07-01

    Four main projects at the interface between organometallic chemistry and homogeneous catalysis were pursued. All were designed to give increased understanding of the mechanisms of organometallic reactions related to homogeneous and heterogeneous catalysis. In addition, a minor study involving {eta}{sup 5}-to {eta}{sup 1}-cyclopentadienyl ring slippage in catalysis was completed.

  15. Analytical Chemistry Division annual progress report for period ending December 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Shults, W.D.; Lyon, W.S. (ed.)

    1980-05-01

    The progress is reported in the following sections: analytical methodology, mass and emission spectrometry, technical support, bio-organic analysis, nuclear and radiochemical analysis, and quality assurance. (DLC)

  16. Progress in long scale length laser plasma interactions

    Science.gov (United States)

    Glenzer, S. H.; Arnold, P.; Bardsley, G.; Berger, R. L.; Bonanno, G.; Borger, T.; Bower, D. E.; Bowers, M.; Bryant, R.; Buckman, S.; Burkhart, S. C.; Campbell, K.; Chrisp, M. P.; Cohen, B. I.; Constantin, C.; Cooper, F.; Cox, J.; Dewald, E.; Divol, L.; Dixit, S.; Duncan, J.; Eder, D.; Edwards, J.; Erbert, G.; Felker, B.; Fornes, J.; Frieders, G.; Froula, D. H.; Gardner, S. D.; Gates, C.; Gonzalez, M.; Grace, S.; Gregori, G.; Greenwood, A.; Griffith, R.; Hall, T.; Hammel, B. A.; Haynam, C.; Heestand, G.; Henesian, M.; Hermes, G.; Hinkel, D.; Holder, J.; Holdner, F.; Holtmeier, G.; Hsing, W.; Huber, S.; James, T.; Johnson, S.; Jones, O. S.; Kalantar, D.; Kamperschroer, J. H.; Kauffman, R.; Kelleher, T.; Knight, J.; Kirkwood, R. K.; Kruer, W. L.; Labiak, W.; Landen, O. L.; Langdon, A. B.; Langer, S.; Latray, D.; Lee, A.; Lee, F. D.; Lund, D.; MacGowan, B.; Marshall, S.; McBride, J.; McCarville, T.; McGrew, L.; Mackinnon, A. J.; Mahavandi, S.; Manes, K.; Marshall, C.; Menapace, J.; Mertens, E.; Meezan, N.; Miller, G.; Montelongo, S.; Moody, J. D.; Moses, E.; Munro, D.; Murray, J.; Neumann, J.; Newton, M.; Ng, E.; Niemann, C.; Nikitin, A.; Opsahl, P.; Padilla, E.; Parham, T.; Parrish, G.; Petty, C.; Polk, M.; Powell, C.; Reinbachs, I.; Rekow, V.; Rinnert, R.; Riordan, B.; Rhodes, M.; Roberts, V.; Robey, H.; Ross, G.; Sailors, S.; Saunders, R.; Schmitt, M.; Schneider, M. B.; Shiromizu, S.; Spaeth, M.; Stephens, A.; Still, B.; Suter, L. J.; Tietbohl, G.; Tobin, M.; Tuck, J.; Van Wonterghem, B. M.; Vidal, R.; Voloshin, D.; Wallace, R.; Wegner, P.; Whitman, P.; Williams, E. A.; Williams, K.; Winward, K.; Work, K.; Young, B.; Young, P. E.; Zapata, P.; Bahr, R. E.; Seka, W.; Fernandez, J.; Montgomery, D.; Rose, H.

    2004-12-01

    The first experiments on the National Ignition Facility (NIF) have employed the first four beams to measure propagation and laser backscattering losses in large ignition-size plasmas. Gas-filled targets between 2 and 7 mm length have been heated from one side by overlapping the focal spots of the four beams from one quad operated at 351 nm (3ω) with a total intensity of 2 × 1015 W cm-2. The targets were filled with 1 atm of CO2 producing up to 7 mm long homogeneously heated plasmas with densities of ne = 6 × 1020 cm-3 and temperatures of Te = 2 keV. The high energy in an NIF quad of beams of 16 kJ, illuminating the target from one direction, creates unique conditions for the study of laser-plasma interactions at scale lengths not previously accessible. The propagation through the large-scale plasma was measured with a gated x-ray imager that was filtered for 3.5 keV x-rays. These data indicate that the beams interact with the full length of this ignition-scale plasma during the last ~1 ns of the experiment. During that time, the full aperture measurements of the stimulated Brillouin scattering and stimulated Raman scattering show scattering into the four focusing lenses of 3% for the smallest length (~2 mm), increasing to 10-12% for ~7 mm. These results demonstrate the NIF experimental capabilities and further provide a benchmark for three-dimensional modelling of the laser-plasma interactions at ignition-size scale lengths.

  17. Progress toward a full scale mobile satellite system for Canada

    Science.gov (United States)

    Roscoe, Orest S.

    The MSAT satellite, planned for launch in early 1994, will provide full scale, satellite based, mobile voice and data communication services to Canada. The MSAT system will provide mobile telephone, mobile radio and mobile data services to customers on the move in any part of North America. The Telesat Mobile Inc. (TMI) satellite will be backed up by a similar satellite to be operated by the American Mobile Satellite Corporation (AMSC) in the United States. An early entry mobile data service was inaugurated in the second quarter of 1990 using channels leased from INMARSAT on Marisat or Marecs-B. The baseline TMI system is described, beginning with the MSAT satellite under contract. The network architecture and the control system that are under development to support the mobile services are discussed. Since it is clearly desirable to have a North American system, such that customers may buy a mobile earth terminal (MET) from a number of qualified suppliers and be able to use it either in Canada or the U.S., TMI and AMSC are cooperating closely in the development of the space and ground segments of the system. The time scale for the procurement of all the elements of the systems is discussed.

  18. Nanometer-Scale Chemistry of a Calcite Biomineralization Template: Implications for Skeletal Composition and Nucleation

    Science.gov (United States)

    Bonnin, Elisa A.; Perea, Daniel E.; Spero, Howard J.; Zhu, Zihua; Winters, Maria; Hönisch, Bärbel; Russell, Ann D.; Fehrenbacher, Jennifer S.; Gagnon, Alexander C.

    2016-01-01

    Plankton, corals, and other organisms produce calcium carbonate skeletons that are integral to their survival, form a key component of the global carbon cycle, and record an archive of past oceanographic conditions in their geochemistry. A key aspect of the formation of these biominerals is the interaction between organic templating structures and mineral precipitation processes. Laboratory-based studies have shown that these atomic-scale processes can profoundly influence the architecture and composition of minerals, but their importance in calcifying organisms is poorly understood because it is difficult to measure the chemistry of in vivo biomineral interfaces at spatially relevant scales. Understanding the role of templates in biomineral nucleation, and their importance in skeletal geochemistry requires an integrated, multiscale approach, which can place atom-scale observations of organic-mineral interfaces within a broader structural and geochemical context. Here we map the chemistry of an embedded organic template structure within a carbonate skeleton of the foraminifera Orbulina universa using both atom probe tomography (APT), a 3D chemical imaging technique with Ångström-level spatial resolution, and time-of-flight secondary ionization mass spectrometry (ToF-SIMS), a 2D chemical imaging technique with submicron resolution. We quantitatively link these observations, revealing that the organic template in O. universa is uniquely enriched in both Na and Mg, and contributes to intraskeletal chemical heterogeneity. Our APT analyses reveal the cation composition of the organic surface, offering evidence to suggest that cations other than Ca2+, previously considered passive spectator ions in biomineral templating, may be important in defining the energetics of carbonate nucleation on organic templates. PMID:27794119

  19. Developing A Renewable Energy Awareness Scale For Pre-service Chemistry Teachers

    Directory of Open Access Journals (Sweden)

    Soner YAVUZ

    2006-01-01

    Full Text Available Developing A Renewable Energy Awareness Scale For Pre-service Chemistry Teachers Inci MORGIL Nilgün SECKEN A. Seda YUCEL Ozge OZYALCIN OSKAY Soner YAVUZ and Evrim URAL Hacettepe University, Faculty of Education, Department of Chemistry Education, 06800 Beytepe, Ankara, TURKEY ABSTRACT In times when human beings used to live in a natural environment, their needs were also provided by natural resources. With the increases in population in time, human beings started to look for new resources willing to get “the more” and “the fastest”. Just like the invention of steam, firstly, they increased the density of the resources and produced “more” energy. However, instead of working on the density of water, which spreads with the solar energy, they chose an easier way, which was fuel that produced more energy when burnt. Unfortunately, the damages these fuel products create in the atmosphere and environment shaded their benefits. It did not take so long for the earth to run out of energy resources and to threaten environmental and human health. As a result of that, new energy resources were started to be sought and the studies enlightened the concepts of sustainable, renewable energy. Renewable energy is defined as “the energy source, which continues its existence for the following days within the evolution of nature”. Educators pointed out a need in students for gaining consciousness on renewable energy resources. In the light of the importance of renewable and sustainable energy, a “Renewable Energy Awareness Scale” that questioned to what extent the individuals were aware of renewable energy was developed. The Renewable Energy Awareness Scale, which consisted of 50 items, was administered as a pilot study. The factor analysis concluded with a scale of 39 items with a reliability coefficient of 0.944 was developed.

  20. Analytical Chemistry Division annual progress report for period ending December 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Shults, W.D.

    1993-04-01

    This report is divided into: Analytical spectroscopy (optical spectroscopy, organic mass spectrometry, inorganic mass spectrometry, secondary ion mass spectrometry), inorganic and radiochemistry (transuranium and activation analysis, low-level radiochemical analysis, inorganic analysis, radioactive materials analysis, special projects), organic chemistry (organic spectroscopy, separations and synthesis, special projects, organic analysis, ORNL/UT research program), operations (quality assurance/quality control, environmental protection, safety, analytical improvement, training, radiation control), education programs, supplementary activities, and presentation of research results. Tables are included for articles reviewed or refereed for periodicals, analytical service work, division manpower and financial summary, and organization chart; a glossary is also included.

  1. Cold molecules: Progress in quantum engineering of chemistry and quantum matter

    Science.gov (United States)

    Bohn, John L.; Rey, Ana Maria; Ye, Jun

    2017-09-01

    Cooling atoms to ultralow temperatures has produced a wealth of opportunities in fundamental physics, precision metrology, and quantum science. The more recent application of sophisticated cooling techniques to molecules, which has been more challenging to implement owing to the complexity of molecular structures, has now opened the door to the longstanding goal of precisely controlling molecular internal and external degrees of freedom and the resulting interaction processes. This line of research can leverage fundamental insights into how molecules interact and evolve to enable the control of reaction chemistry and the design and realization of a range of advanced quantum materials.

  2. Chemistry of silica scale mitigation for RO desalination with particular reference to remote operations.

    Science.gov (United States)

    Milne, Nicholas A; O'Reilly, Tom; Sanciolo, Peter; Ostarcevic, Eddy; Beighton, Mark; Taylor, Kelvin; Mullett, Mark; Tarquin, Anthony J; Gray, Stephen R

    2014-11-15

    Silica scaling in reverse osmosis of groundwater is a significant issue in water stressed areas due to the limitations that scaling imposes on water recovery. While calcium and magnesium scaling potential can be significantly reduced by the use of ion exchange or other softening processes, the silica scaling potential typically remains. Improving the recovery of reverse osmosis by limiting the potential for silica scale is important in ensuring maximum water recovery. This is particularly important for mining and natural gas industries that are located in remote regions. The remote nature of these sites imposes three major restrictions on the silica scale mitigation process. Firstly, the generation of poorly dewaterable sludges must be avoided. Also, the quality of any reverse osmosis (RO) permeate must be able to meet the end use requirements, particularly for boilers. Finally, silica removal should not impact upon other potentially useful or valuable components within the brine, and should not make the disposal of the unusable waste brine components more difficult. Reduction of scaling potential can be achieved in three main ways: operating RO at high pH after hardness has been removed, operating at low pH, and reducing the silica concentration either in pretreatment or by using an interstage technique. Operating at high pH has the initial requirement of hardness removal to prevent scaling and this could be an issue on some sites. Hardness removal operations that use ion exchange resins may be challenged by water chemistry and the operational costs associated with high chemical regeneration costs. Operating at low pH may be more desirable than high pH operation as this can help to reduce the risk of scale formation from calcium or magnesium salts. The drawback comes from the cost of acid, particularly for high-alkalinity waters. There are numerous silica removal techniques including chemical dosing of lime, or aluminium or iron salts, electrocoagulation

  3. An overview and recent progress in the chemistry of uranium extraction from seawater.

    Science.gov (United States)

    Parker, B F; Zhang, Z; Rao, L; Arnold, J

    2018-01-15

    This review provides a brief background on the extraction of uranium from seawater as well as recent work by the United States Department of Energy on this project. The world's oceans contain uranium at 3 parts per billion, and despite this low concentration, there has been historical interest in harvesting it, mainly in Japan in the 1980s and the United States in this decade. Improvements in materials, chemistry, and deployment methods have all been made, with the ultimate goal of lower cost. This has been partially realized, dropping from approximately $2000 per kg U3O8 extracted in 1984 to $500 per kg today, although this is not yet competitive with terrestrial uranium. This technology may become cost-competitive if the cost of land-based uranium rises, especially if seawater extraction technology is improved further. The coordination chemistry aspects of the project are described in more detail, exploring the functional groups that are present on typical polymer sorbents as well as small-molecule analogues of these ligands. Selectivity for uranium over other metals, particularly vanadium, remains problematic, and techniques to both quantify binding strength and selectivity in order to overcome this issue are essential for future cost improvements.

  4. Progresses in the operation of large scale LBE loop: Helios

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Lim; Seung Ho, Jeong; Young Jin, Oh; Hyo On, Nam; Chi Bum, Bahn; Seung Hee, Chang; Won Chang, Nam; Kyung Ha, Ryu; Tai Hyun, Lee; Seung Gi, Lee; Na Young, Lee; Il Soon, Hwang [Seoul National Univ., Nuclear Transmutation Energy Research Center of Korea (NUTRECK) (Korea, Republic of)

    2007-07-01

    A 12 m tall LBE (lead-bismuth eutectic) coolant loop, named as HELIOS (Heavy Eutectic liquid metal Loop for Investigation of Operability and Safety of PEACER), has been developed by thermal-hydraulic scaling of the PEACER-300-MWe (Proliferation-resistant, Environment-friendly, Accident-tolerant, Continual and Economical Reactor). HELIOS has 5 main vessels: mockup core, expansion tank, heat exchanger, sump tank (containing sump pump inside) and storage tank. The total power of the 4 four main heaters in the mockup core is 60 kW. Natural circulation experiment and material test are principal purposes of HELIOS operation. During preliminary tests, many practical difficulties arouse with sensors for pressure measurement and with the orifice flow meter for flow rate measurement. After modification and calibration of sensors, forced circulation and natural circulation tests were performed. For the long term material test, specimen cage was designed to control the flow-rate only by natural circulation. The required flow-rate of material test section is over 1 m/s under natural circulation condition. Natural circulation capability of HELIOS is expected to be sufficient to achieve flow velocity in test sections. Preliminary corrosion tests were performed in order to establish optimum process of LBE corrosion experiment in large loop.

  5. Calcium-based multi-element chemistry for grid-scale electrochemical energy storage

    Science.gov (United States)

    Ouchi, Takanari; Kim, Hojong; Spatocco, Brian L.; Sadoway, Donald R.

    2016-03-01

    Calcium is an attractive material for the negative electrode in a rechargeable battery due to its low electronegativity (high cell voltage), double valence, earth abundance and low cost; however, the use of calcium has historically eluded researchers due to its high melting temperature, high reactivity and unfavorably high solubility in molten salts. Here we demonstrate a long-cycle-life calcium-metal-based rechargeable battery for grid-scale energy storage. By deploying a multi-cation binary electrolyte in concert with an alloyed negative electrode, calcium solubility in the electrolyte is suppressed and operating temperature is reduced. These chemical mitigation strategies also engage another element in energy storage reactions resulting in a multi-element battery. These initial results demonstrate how the synergistic effects of deploying multiple chemical mitigation strategies coupled with the relaxation of the requirement of a single itinerant ion can unlock calcium-based chemistries and produce a battery with enhanced performance.

  6. Chemistry research and development. Progress report, December 1978-May 1979. [Component, pilot plant, instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Miner, F. J.

    1980-06-30

    Progress and activities are reported on component development, pilot plant development, and instrumentation and statistical systems. Specific items studied include processing of pond sludge, transport of radioactive materials and wastes, corrosion, decontamination and cleaning, fluidized-bed incineration, Pu contamination of soils, chemical analysis, radiometric analysis, security. (DLC)

  7. Analytical Chemistry Division annual progress report for period ending December 31, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, W.S. (ed.)

    1985-04-01

    Progress reports are presented for the following sections: analytical methodology; mass and emission spectroscopy; radioactive materials analysis; bio/organic analysis; and general and environmental analysis; quality assurance, safety, and tabulation analyses. In addition a list of publications and oral presentations and supplemental activities are included.

  8. Analytical Chemistry Division annual progress report for period ending December 31, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Lyon, W.S. (ed.)

    1984-05-01

    Progress and activities are reported in: analytical methodology, mass and emission spectrometry, radioactive materials analysis, bio/organic analysis, general and environmental analysis, and quality assurance and safety. Supplementary activities are also discussed, and a bibliography of publications is also included. (DLC)

  9. Recent progress in orbital-free density functional theory (recent advances in computational chemistry)

    CERN Document Server

    Wesolowski, Tomasz A

    2013-01-01

    This is a comprehensive overview of state-of-the-art computational methods based on orbital-free formulation of density functional theory completed by the most recent developments concerning the exact properties, approximations, and interpretations of the relevant quantities in density functional theory. The book is a compilation of contributions stemming from a series of workshops which had been taking place since 2002. It not only chronicles many of the latest developments but also summarises some of the more significant ones. The chapters are mainly reviews of sub-domains but also include original research. Readership: Graduate students, academics and researchers in computational chemistry. Atomic & molecular physicists, theoretical physicists, theoretical chemists, physical chemists and chemical physicists.

  10. Compilation and analyses of emissions inventories for the NOAA atmospheric chemistry project. Progress report, August 1997

    Energy Technology Data Exchange (ETDEWEB)

    Benkovitz, C.M.

    1997-09-01

    Global inventories of anthropogenic emissions of oxides of nitrogen for circa 1985 and 1990 and non-methane volatile organic compounds (NMVOCs) for circa 1990 have been compiled by this project. Work on the inventories has been carried out under the umbrella of the Global Emissions Inventory Activity of the International Global Atmospheric Chemistry program. Global emissions of NOx for 1985 are estimated to be 21 Tg N/yr, with approximately 84% originating in the Northern Hemisphere. The global emissions for 1990 are 31 Tg N/yr for NOx and 173 Gg NMVOC/yr. Ongoing research activities for this project continue to address emissions of both NOx and NMVOCs. Future tasks include: evaluation of more detailed regional emissions estimates and update of the default 1990 inventories with the appropriate estimates; derivation of quantitative uncertainty estimates for the emission values; and development of emissions estimates for 1995.

  11. [Research progress and trend analysis of biology and chemistry of Taxus medicinal resources].

    Science.gov (United States)

    Hao, Da-Cheng; Xiao, Pei-Gen; Peng, Yong; Liu, Ming; Huo, Li

    2012-07-01

    Taxus is the source plant of anti-cancer drug paclitaxel and its biosynthetic precursor, analogs and derivatives, which has been studying for decades. There are many endemic Taxus species in China, which have been studied in the field of multiple disciplines. Based on the recent studies of the researchers, this review comments on the study of Taxus biology and chemistry. The bibliometric method is used to quantify the global scientific production of Taxus-related research, and identify patterns and tendencies of Taxus-related articles. Gaps are present in knowledge about the genomics, epigenomics, transcriptomics, proteomics, metabolomics and bioinformatics of Taxus and their endophytic fungi. Systems biology and various omics technologies will play an increasingly important role in the coming decades.

  12. Reaction Scale and Green Chemistry: Microscale or Macroscale, Which is Greener?

    Science.gov (United States)

    Duarte, Rita C. C.; Ribeiro, M. Gabriela T. C.; Machado, Adelio A. S. C.

    2017-01-01

    The different ways microscale and green chemistry allow reducing the deleterious impacts of chemistry on human health and the environment are discussed in terms of their different basic paradigms: green chemistry follows the ecologic paradigm and microscale the risk paradigm. A study of the synthesis of 1-bromobutane at macro- ? microscale (109.3…

  13. Disease Severity and Progression in Progressive Supranuclear Palsy and Multiple System Atrophy: Validation of the NNIPPS – PARKINSON PLUS SCALE

    Science.gov (United States)

    Payan, Christine A. M.; Viallet, François; Landwehrmeyer, Bernhard G.; Bonnet, Anne-Marie; Borg, Michel; Durif, Franck; Lacomblez, Lucette; Bloch, Frédéric; Verny, Marc; Fermanian, Jacques; Agid, Yves; Ludolph, Albert C.

    2011-01-01

    Background The Natural History and Neuroprotection in Parkinson Plus Syndromes (NNIPPS) study was a large phase III randomized placebo-controlled trial of riluzole in Progressive Supranuclear Palsy (PSP, n = 362) and Multiple System Atrophy (MSA, n = 398). To assess disease severity and progression, we constructed and validated a new clinical rating scale as an ancillary study. Methods and Findings Patients were assessed at entry and 6-montly for up to 3 years. Evaluation of the scale's psychometric properties included reliability (n = 116), validity (n = 760), and responsiveness (n = 642). Among the 85 items of the initial scale, factor analysis revealed 83 items contributing to 15 clinically relevant dimensions, including Activity of daily Living/Mobility, Axial bradykinesia, Limb bradykinesia, Rigidity, Oculomotor, Cerebellar, Bulbar/Pseudo-bulbar, Mental, Orthostatic, Urinary, Limb dystonia, Axial dystonia, Pyramidal, Myoclonus and Tremor. All but the Pyramidal dimension demonstrated good internal consistency (Cronbach α≥0.70). Inter-rater reliability was high for the total score (Intra-class coefficient = 0.94) and 9 dimensions (Intra-class coefficient = 0.80–0.93), and moderate (Intra-class coefficient = 0.54–0.77) for 6. Correlations of the total score with other clinical measures of severity were good (rho≥0.70). The total score was significantly and linearly related to survival (p<0.0001). Responsiveness expressed as the Standardized Response Mean was high for the total score slope of change (SRM = 1.10), though higher in PSP (SRM = 1.25) than in MSA (SRM = 1.0), indicating a more rapid progression of PSP. The slope of change was constant with increasing disease severity demonstrating good linearity of the scale throughout disease stages. Although MSA and PSP differed quantitatively on the total score at entry and on rate of progression, the relative contribution of clinical dimensions to overall

  14. Disease severity and progression in progressive supranuclear palsy and multiple system atrophy: validation of the NNIPPS--Parkinson Plus Scale.

    Directory of Open Access Journals (Sweden)

    Christine A M Payan

    Full Text Available The Natural History and Neuroprotection in Parkinson Plus Syndromes (NNIPPS study was a large phase III randomized placebo-controlled trial of riluzole in Progressive Supranuclear Palsy (PSP, n = 362 and Multiple System Atrophy (MSA, n = 398. To assess disease severity and progression, we constructed and validated a new clinical rating scale as an ancillary study.Patients were assessed at entry and 6-montly for up to 3 years. Evaluation of the scale's psychometric properties included reliability (n = 116, validity (n = 760, and responsiveness (n = 642. Among the 85 items of the initial scale, factor analysis revealed 83 items contributing to 15 clinically relevant dimensions, including Activity of daily Living/Mobility, Axial bradykinesia, Limb bradykinesia, Rigidity, Oculomotor, Cerebellar, Bulbar/Pseudo-bulbar, Mental, Orthostatic, Urinary, Limb dystonia, Axial dystonia, Pyramidal, Myoclonus and Tremor. All but the Pyramidal dimension demonstrated good internal consistency (Cronbach α ≥ 0.70. Inter-rater reliability was high for the total score (Intra-class coefficient = 0.94 and 9 dimensions (Intra-class coefficient = 0.80-0.93, and moderate (Intra-class coefficient = 0.54-0.77 for 6. Correlations of the total score with other clinical measures of severity were good (rho ≥ 0.70. The total score was significantly and linearly related to survival (p<0.0001. Responsiveness expressed as the Standardized Response Mean was high for the total score slope of change (SRM = 1.10, though higher in PSP (SRM = 1.25 than in MSA (SRM = 1.0, indicating a more rapid progression of PSP. The slope of change was constant with increasing disease severity demonstrating good linearity of the scale throughout disease stages. Although MSA and PSP differed quantitatively on the total score at entry and on rate of progression, the relative contribution of clinical dimensions to overall severity and progression was similar.The NNIPPS-PPS has suitable validity, is

  15. Fuels, materials, and coolant chemistry programs. Annual technical progress report, GFY 1969

    Energy Technology Data Exchange (ETDEWEB)

    Murbach, E. W.; Atkins, D. F.

    1970-09-01

    The objectives of the project are to (1) manage a source of stock systems quality sodium for the program, (2) monitor the compositions of sodium and of gas atmospheres in use on all the subtasks in the program; and provide a management system for ensuring the use of proper procedures in sampling, transferring, and analyzing of sodium, and (3) procure, characterize and manage a supply of cladding materials for the program. The report provides technical progress during fiscal year 1969.

  16. Fenton chemistry-based detemplation of an industrially relevant microcrystalline beta zeolite. Optimization and scaling-up studies

    NARCIS (Netherlands)

    Ortiz-Iniesta, Maria Jesus; Melian-Cabrera, Ignacio

    A mild template removal of microcrystalline beta zeolite, based on Fenton chemistry, was optimized. Fenton detemplation was studied in terms of applicability conditions window, reaction rate and scale up. TGA and CHN elemental analysis were used to evaluate the detemplation effectiveness, while 'CP,

  17. PubChemQC Project: A Large-Scale First-Principles Electronic Structure Database for Data-Driven Chemistry.

    Science.gov (United States)

    Nakata, Maho; Shimazaki, Tomomi

    2017-06-26

    Large-scale molecular databases play an essential role in the investigation of various subjects such as the development of organic materials, in silico drug design, and data-driven studies with machine learning. We have developed a large-scale quantum chemistry database based on first-principles methods. Our database currently contains the ground-state electronic structures of 3 million molecules based on density functional theory (DFT) at the B3LYP/6-31G* level, and we successively calculated 10 low-lying excited states of over 2 million molecules via time-dependent DFT with the B3LYP functional and the 6-31+G* basis set. To select the molecules calculated in our project, we referred to the PubChem Project, which was used as the source of the molecular structures in short strings using the InChI and SMILES representations. Accordingly, we have named our quantum chemistry database project "PubChemQC" ( http://pubchemqc.riken.jp/ ) and placed it in the public domain. In this paper, we show the fundamental features of the PubChemQC database and discuss the techniques used to construct the data set for large-scale quantum chemistry calculations. We also present a machine learning approach to predict the electronic structure of molecules as an example to demonstrate the suitability of the large-scale quantum chemistry database.

  18. Atomic-scale simulation of dust grain collisions: Surface chemistry and dissipation beyond existing theory

    Science.gov (United States)

    Quadery, Abrar H.; Doan, Baochi D.; Tucker, William C.; Dove, Adrienne R.; Schelling, Patrick K.

    2017-10-01

    The early stages of planet formation involve steps where submicron-sized dust particles collide to form aggregates. However, the mechanism through which millimeter-sized particles aggregate to kilometer-sized planetesimals is still not understood. Dust grain collision experiments carried out in the environment of the Earth lead to the prediction of a 'bouncing barrier' at millimeter-sizes. Theoretical models, e.g., Johnson-Kendall-Roberts and Derjaguin-Muller-Toporov theories, lack two key features, namely the chemistry of dust grain surfaces, and a mechanism for atomic-scale dissipation of energy. Moreover, interaction strengths in these models are parameterized based on experiments done in the Earth's environment. To address these issues, we performed atomic-scale simulations of collisions between nonhydroxylated and hydroxylated amorphous silica nanoparticles. We used the ReaxFF approach which enables modeling chemical reactions using an empirical potential. We found that nonhydroxylated nanograins tend to adhere with much higher probability than suggested by existing theories. By contrast, hydroxylated nanograins exhibit a strong tendency to bounce. Also, the interaction between dust grains has the characteristics of a strong chemical force instead of weak van der Waals forces. This suggests that the formation of strong chemical bonds and dissipation via internal atomic vibration may result in aggregation beyond what is expected based on our current understanding. Our results also indicate that experiments should more carefully consider surface conditions to mimic the space environment. We also report results of simulations with molten silica nanoparticles. It is found that molten particles are more likely to adhere due to viscous dissipation, which supports theories that suggest aggregation to kilometer scales might require grains to be in a molten state.

  19. Air-chemistry "turbulence": power-law scaling and statistical regularity

    Directory of Open Access Journals (Sweden)

    H.-m. Hsu

    2011-08-01

    Full Text Available With the intent to gain further knowledge on the spectral structures and statistical regularities of surface atmospheric chemistry, the chemical gases (NO, NO2, NOx, CO, SO2, and O3 and aerosol (PM10 measured at 74 air quality monitoring stations over the island of Taiwan are analyzed for the year of 2004 at hourly resolution. They represent a range of surface air quality with a mixed combination of geographic settings, and include urban/rural, coastal/inland, plain/hill, and industrial/agricultural locations. In addition to the well-known semi-diurnal and diurnal oscillations, weekly, and intermediate (20 ~ 30 days peaks are also identified with the continuous wavelet transform (CWT. The spectra indicate power-law scaling regions for the frequencies higher than the diurnal and those lower than the diurnal with the average exponents of −5/3 and −1, respectively. These dual-exponents are corroborated with those with the detrended fluctuation analysis in the corresponding time-lag regions. These exponents are mostly independent of the averages and standard deviations of time series measured at various geographic settings, i.e., the spatial inhomogeneities. In other words, they possess dominant universal structures. After spectral coefficients from the CWT decomposition are grouped according to the spectral bands, and inverted separately, the PDFs of the reconstructed time series for the high-frequency band demonstrate the interesting statistical regularity, −3 power-law scaling for the heavy tails, consistently. Such spectral peaks, dual-exponent structures, and power-law scaling in heavy tails are important structural information, but their relations to turbulence and mesoscale variability require further investigations. This could lead to a better understanding of the processes controlling air quality.

  20. Raven's progressive matrices test: scale construction and verification of "Flynn effect"

    OpenAIRE

    Lopetegui, María Susana; Neer, Rosa Haydée; Rossi Casé, Lilia Elba

    2002-01-01

    In this paper, the scales of Raven's Progressive Matrices Test, General Scale and Advanced Scale, Series II, for the student population (third cycle of EGB and Polimodal ) in the city of La Plata are presented. Considerations are made as regards both the increase in scores (Flynn effect) observed in relation to the previous scale (1964) and the different mean scores according to two age groups (13-16 and 17-18 years of age) and education mode. The findings enabled inferences related to the si...

  1. COMPILATION AND ANALYSES OF EMISSIONS INVENTORIES FOR THE NOAA ATMOSPHERIC CHEMISTRY PROJECT. PROGRESS REPORT, AUGUST 1997.

    Energy Technology Data Exchange (ETDEWEB)

    BENKOVITZ,C.M.

    1997-09-01

    Global inventories of anthropogenic emissions of oxides of nitrogen (NO{sub x}) for circa 1985 and 1990 and Non-Methane Volatile Organic Compounds (NMVOCs) for circa 1990 have been compiled by this project. Work on the inventories has been carried out under the umbrella of the Global Emissions Inventory Activity (GEIA) of the International Global Atmospheric Chemistry (IGAC) Program. The 1985 NO{sub x} inventory was compiled using default data sets of global emissions that were refined via the use of more detailed regional data sets; this inventory is being distributed to the scientific community at large as the GEIA Version 1A inventory. Global emissions of NO{sub x} for 1985 are estimated to be 21 Tg N y{sup -1}, with approximately 84% originating in the Northern Hemisphere. The 1990 inventories of NO{sub x} and NMVOCs were compiled using unified methodologies and data sets in collaboration with the Netherlands National Institute of Public Health and Environmental Protection (Rijksinstituut Voor Volksgezondheid en Milieuhygiene, RIVM) and the Division of Technology for Society of the Netherlands Organization for Applied Scientific Research, (IMW-TNO); these emissions will be used as the default estimates to be updated with more accurate regional data. The NMVOC inventory was gridded and speciated into 23 chemical categories. The resulting global emissions for 1990 are 31 Tg N yr{sup -1} for NO{sub x} and 173 Gg NMVOC yr{sup -1}. Emissions of NO{sub x} are highest in the populated and industrialized areas of eastern North America and across Europe, and in biomass burning areas of South America, Africa, and Asia. Emissions of NMVOCs are highest in biomass burning areas of South America, Africa, and Asia. The 1990 NO{sub x} emissions were gridded to 1{sup o} resolution using surrogate data, and were given seasonal, two-vertical-level resolution and speciated into NO and NO{sub 2} based on proportions derived from the 1985 GEIA Version 1B inventory. Global NMVOC

  2. Large-Scale Parallel Simulations of Turbulent Combustion using Combined Dimension Reduction and Tabulation of Chemistry

    Science.gov (United States)

    2012-05-22

    redistributing the chemistry workload, namely (a) PLP, purely local processing; (b) URAN , the uniform random distribution of chemistry com- putations among...all cores following an early stage of PLP; and (c) P- URAN , a Partitioned URAN strategy that redistributes the workload within parti- tions or subsets...parallel strate- gies for redistributing the chemistry workload, namely (a) PLP, purely local processing; (b) URAN , the uniform random distribution

  3. Large-scale separation of single-walled carbon nanotubes by electronic type using click chemistry

    Science.gov (United States)

    Um, Jo-Eun; Song, Sun Gu; Yoo, Pil J.; Song, Changsik; Kim, Woo-Jae

    2018-01-01

    Single-walled carbon nanotubes (SWCNTs) can be either metallic or semiconducting, making their separation critical for applications in nanoelectronics, biomedical materials, and solar cells. Herein, we investigate a novel solution-phase separation method based on click chemistry (azide-alkyne Huisgen cycloaddition) and determine its efficiency and scalability. In this method, metallic SWCNTs in metallic/semiconducting SWCNT mixtures are selectively functionalized with alkyne groups by being reacted with 4-propargyloxybenezenediazonium tetrafluoroborate. Subsequently, silica nanoparticles are functionalized with azide groups and reacted with alkyne-bearing metallic SWCNTs in the SWCNT mixture in the presence of a Cu catalyst. As a result, metallic SWCNTs are anchored on silica powder, whereas non-functionalized semiconducting SWCNTs remain in solution. Low-speed centrifugation effectively removes the silica powder with attached metallic SWCNTs, furnishing a solution of highly pure semiconducting SWCNTs, as confirmed by Raman and UV-vis/near-infrared absorption measurements. This novel separation scheme exhibits the advantage of simultaneously separating both metallic and semiconducting SWCNTs from their mixtures, being cost-effective and therefore applicable at an industrial scale.

  4. Sequential Progressions in a Theory-of-Mind Scale: Longitudinal Perspectives

    Science.gov (United States)

    Wellman, Henry M.; Fang, Fuxi; Peterson, Candida C.

    2011-01-01

    Consecutive retestings of 92 U.S. preschoolers (n = 30), Chinese preschoolers (n = 31), and deaf children (n = 31) examined whether the sequences of development apparent in cross-sectional results with a theory-of-mind scale also appeared in longitudinal assessment. Longitudinal data confirmed that theory-of-mind progressions apparent in…

  5. Development and Evaluation of a Chemistry-Specific Version of the Academic Motivation Scale (AMS-Chemistry)

    Science.gov (United States)

    Liu, Yujuan; Ferrell, Brent; Barbera, Jack; Lewis, Jennifer E.

    2017-01-01

    Fundamentally concerned with motivation, self-determination theory (SDT) represents a framework of several mini-theories to explore how social context interacts with people's motivational types categorized by degree of regulation internalization. This paper aims to modify an existing theory-based instrument (Academic Motivation Scale, or AMS) and…

  6. Regional scale effects of the aerosol cloud interaction simulated with an online coupled comprehensive chemistry model

    Directory of Open Access Journals (Sweden)

    M. Bangert

    2011-05-01

    Full Text Available We have extended the coupled mesoscale atmosphere and chemistry model COSMO-ART to account for the transformation of aerosol particles into cloud condensation nuclei and to quantify their interaction with warm cloud microphysics on the regional scale. The new model system aims to fill the gap between cloud resolving models and global scale models. It represents the very complex microscale aerosol and cloud physics as detailed as possible, whereas the continental domain size and efficient codes will allow for both studying weather and regional climate. The model system is applied in a first extended case study for Europe for a cloudy five day period in August 2005.

    The model results show that the mean cloud droplet number concentration of clouds is correlated with the structure of the terrain, and we present a terrain slope parameter TS to classify this dependency. We propose to use this relationship to parameterize the probability density function, PDF, of subgrid-scale cloud updraft velocity in the activation parameterizations of climate models.

    The simulations show that the presence of cloud condensation nuclei (CCN and clouds are closely related spatially. We find high aerosol and CCN number concentrations in the vicinity of clouds at high altitudes. The nucleation of secondary particles is enhanced above the clouds. This is caused by an efficient formation of gaseous aerosol precursors above the cloud due to more available radiation, transport of gases in clean air above the cloud, and humid conditions. Therefore the treatment of complex photochemistry is crucial in atmospheric models to simulate the distribution of CCN.

    The mean cloud droplet number concentration and droplet diameter showed a close link to the change in the aerosol. To quantify the net impact of an aerosol change on the precipitation we calculated the precipitation susceptibility β for the whole model domain over a period of two days with

  7. An Evaluation of Ozone Dry Deposition in Global Scale Chemistry Climate Models

    Science.gov (United States)

    Hardacre, C.; Wild, O.; Emberson, L.

    2014-12-01

    Dry deposition of atmospheric oxidants to the Earth's surface or vegetation is important as both a major removal pathway governing their atmospheric abundance and as a key input of oxidants and nutrients to sensitive vegetation surfaces. By linking the atmosphere and biosphere, dry deposition processes contribute to wider climate and Earth system feedbacks which need to be adequately quantified for a full understanding of Earth system responses. In addition, they have immediate policy-relevant implications for air quality, ecosystem health and crop productivity that need to be assessed on local, regional and global scales. In this study we use results from the recent Task Force on Hemispheric Transport of Air Pollution (HTAP) model intercomparison to explore how dry deposition of ozone varies across 15 current atmospheric chemistry and transport models. While most models take a similar, resistances-based approach to parameterising dry deposition, there are substantial differences across the models in the magnitude and variability of the annual and monthly ozone deposition fluxes which contribute to the differences in modelled surface ozone and in the global tropospheric ozone budget. We find that the range in global ozone deposition flux over the HTAP model ensemble spans about 30% with deposition to ocean, grass land and tropical forests being particularly variable. Further, we compare modelled dry deposition of ozone to measurements made at a variety of locations in Europe and North America, noting differences of up to a factor of two but no clear systematic bias over the sites examined. We extend this analysis by running sensitivity studies to determine the importance of key parameters in the ozone dry deposition process, including soil moisture and leaf area index. This study provides an important first step towards quantifying the uncertainty in ozone dry deposition and permitting a more thorough, observation-based evaluation of this important process.

  8. Experimental and Numerical Evaluation of Progressive Collapse Behavior in Scaled RC Beam-Column Subassemblage

    Directory of Open Access Journals (Sweden)

    Rasool Ahmadi

    2016-01-01

    Full Text Available An experimental test was carried out on a 3/10 scale subassemblage in order to investigate the progressive collapse behavior of reinforced concrete (RC structures. Investigation of alternative load paths and resistance mechanisms in scaled subassemblage and differences between the results of full-scale and scaled specimens are the main goals of this research. Main characteristics of specimen response including load-displacement curve, mechanism of formation and development of cracks, and failure mode of the scaled specimen had good agreement with the full-scale specimen. In order to provide a reliable numerical model for progressive collapse analysis of RC beam-column subassemblages, a macromodel was also developed. First, numerical model was validated with experimental tests in the literature. Then, experimental results in this study were compared with validated numerical results. It is shown that the proposed macromodel can provide a precise estimation of collapse behavior of RC subassemblages under the middle column removal scenario. In addition, for further evaluation, using the validated numerical model, parametric study of new subassemblages with different details, geometric and boundary conditions, was also done.

  9. Severity score system for progressive myelopathy: development and validation of a new clinical scale

    Science.gov (United States)

    Castilhos, R.M.; Blank, D.; Netto, C.B.O.; Souza, C.F.M.; Fernandes, L.N.T.; Schwartz, I.V.D.; Giugliani, R.; Jardim, L.B.

    2012-01-01

    Progressive myelopathies can be secondary to inborn errors of metabolism (IEM) such as mucopolysaccharidosis, mucolipidosis, and adrenomyeloneuropathy. The available scale, Japanese Orthopaedic Association (JOA) score, was validated only for degenerative vertebral diseases. Our objective is to propose and validate a new scale addressing progressive myelopathies and to present validating data for JOA in these diseases. A new scale, Severity Score System for Progressive Myelopathy (SSPROM), was constructed covering motor disability, sphincter dysfunction, spasticity, and sensory losses. Inter-and intra-rater reliabilities were measured. External validation was tested by applying JOA, the Expanded Disability Status Scale (EDSS), the Barthel index, and the Osame Motor Disability Score. Thirty-eight patients, 17 with adrenomyeloneuropathy, 3 with mucopolysaccharidosis I, 3 with mucopolysaccharidosis IV, 2 with mucopolysaccharidosis VI, 2 with mucolipidosis, and 11 with human T-cell lymphotropic virus type-1 (HTLV-1)-associated myelopathy participated in the study. The mean ± SD SSPROM and JOA scores were 74.6 ± 11.4 and 12.4 ± 2.3, respectively. Construct validity for SSPROM (JOA: r = 0.84, P myelopathies. PMID:22570090

  10. Modeling Macro- and Micro-Scale Turbulent Mixing and Chemistry in Engine Exhaust Plumes

    Science.gov (United States)

    Menon, Suresh

    1998-01-01

    Simulation of turbulent mixing and chemical processes in the near-field plume and plume-vortex regimes has been successfully carried out recently using a reduced gas phase kinetics mechanism which substantially decreased the computational cost. A detailed mechanism including gas phase HOx, NOx, and SOx chemistry between the aircraft exhaust and the ambient air in near-field aircraft plumes is compiled. A reduced mechanism capturing the major chemical pathways is developed. Predictions by the reduced mechanism are found to be in good agreement with those by the detailed mechanism. With the reduced chemistry, the computer CPU time is saved by a factor of more than 3.5 for the near-field plume modeling. Distributions of major chemical species are obtained and analyzed. The computed sensitivities of major species with respect to reaction step are deduced for identification of the dominant gas phase kinetic reaction pathways in the jet plume. Both the near field plume and the plume-vortex regimes were investigated using advanced mixing models. In the near field, a stand-alone mixing model was used to investigate the impact of turbulent mixing on the micro- and macro-scale mixing processes using a reduced reaction kinetics model. The plume-vortex regime was simulated using a large-eddy simulation model. Vortex plume behind Boeing 737 and 747 aircraft was simulated along with relevant kinetics. Many features of the computed flow field show reasonable agreement with data. The entrainment of the engine plumes into the wing tip vortices and also the partial detrainment of the plume were numerically captured. The impact of fluid mechanics on the chemical processes was also studied. Results show that there are significant differences between spatial and temporal simulations especially in the predicted SO3 concentrations. This has important implications for the prediction of sulfuric acid aerosols in the wake and may partly explain the discrepancy between past numerical studies

  11. Severity score system for progressive myelopathy: development and validation of a new clinical scale

    Directory of Open Access Journals (Sweden)

    R.M. Castilhos

    2012-07-01

    Full Text Available Progressive myelopathies can be secondary to inborn errors of metabolism (IEM such as mucopolysaccharidosis, mucolipidosis, and adrenomyeloneuropathy. The available scale, Japanese Orthopaedic Association (JOA score, was validated only for degenerative vertebral diseases. Our objective is to propose and validate a new scale addressing progressive myelopathies and to present validating data for JOA in these diseases. A new scale, Severity Score System for Progressive Myelopathy (SSPROM, covering motor disability, sphincter dysfunction, spasticity, and sensory losses. Inter- and intra-rater reliabilities were measured. External validation was tested by applying JOA, the Expanded Disability Status Scale (EDSS, the Barthel index, and the Osame Motor Disability Score. Thirty-eight patients, 17 with adrenomyeloneuropathy, 3 with mucopolysaccharidosis I, 3 with mucopolysaccharidosis IV, 2 with mucopolysaccharidosis VI, 2 with mucolipidosis, and 11 with human T-cell lymphotropic virus type-1 (HTLV-1-associated myelopathy participated in the study. The mean ± SD SSPROM and JOA scores were 74.6 ± 11.4 and 12.4 ± 2.3, respectively. Construct validity for SSPROM (JOA: r = 0.84, P < 0.0001; EDSS: r = -0.83, P < 0.0001; Barthel: r = 0.56, P < 0.002; Osame: r = -0.94, P < 0.0001 and reliability (intra-rater: r = 0.83, P < 0.0001; inter-rater: r = 0.94, P < 0.0001 were demonstrated. The metric properties of JOA were similar to those found in SSPROM. Several clinimetric requirements were met for both SSPROM and JOA scales. Since SSPROM has a wider range, it should be useful for follow-up studies on IEM myelopathies.

  12. Large Scale Observatories for Changing Cold Regions - Recent Progress and Future Vision

    Science.gov (United States)

    Wheater, H. S.; Pomeroy, J. W.; Carey, S. K.; DeBeer, C. M.

    2016-12-01

    Observatories are at the core of hydrological science and a critical resource for the detection and analysis of environmental change. The combination of multiple pressures on the water environment and new scientific opportunities provides a context where a broader vision is urgently needed. Human activities are increasingly affecting land and water management at multiple scales, so our observatories now need to more fully include the human dimensions of water, including their integration across jurisdictional boundaries and at large basin scales. And large scales are also needed to diagnose and predict impacts of climate change at regional and continental scales, and to address land-water-atmosphere interactions and feedbacks. We argue the need to build on the notable past successes of the World Climate Research Programme and move forward to a new era of globally-distributed large scale observatories. This paper introduces 2 such observatories in rapidly warming western Canada - the 405,000 km2 Saskatchewan and the 1.8 million km2 Mackenzie river basins. We review progress in these multi-scale observatories, including the use of point and small basin-scale observatory sites to observe and diagnose complex regional patterns of hydrological change. And building on new opportunities for observational systems and data assimilation, we present a vision for a pan-Canadian observing system to support the science needed for the management of future societal risk from extreme events and environmental change.

  13. Hot Gas Conditioning: Recent Progress with Larger-Scale Biomass Gasification Systems; Update and Summary of Recent Progress

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D. J.

    2001-09-01

    As a result of environmental and policy considerations, there is increasing interest in using renewable biomass resources as feedstock for power, fuels, and chemicals and hydrogen. Biomass gasification is seen as an important technology component for expanding the use of biomass. Advanced biomass gasification systems provide clean products that can be used as fuel or synthesis gases in a variety of environmentally friendly processes. Advanced end-use technologies such as gas turbines or synthesis gas systems require high quality gases with narrowly defined specifications. Other systems such as boilers may also have fuel quality requirements, but they will be substantially less demanding. The gas product from biomass gasifiers contains quantities of particulates, tars, and other constituents that may exceed these specified limits. As a result, gas cleaning and conditioning will be required in most systems. Over the past decade, significant research and development activities have been conducted on the topic of gas cleanup and conditioning. This report provides an update of efforts related to large-scale biomass gasification systems and summarizes recent progress. Remaining research and development issues are also summarized.

  14. Using Streamwater Chemistry in Flowpath Analysis of Large-Scale Forested Watersheds Near Stowe, VT: Developed vs. Undeveloped Watersheds

    Science.gov (United States)

    Zinni, B. J.; Wemple, B. C.; Lini, A.; James, S. B.

    2004-05-01

    The analysis of flowpaths in small alpine watersheds has provided insight into the interrelationships between overall streamwater chemistry and the various flowpaths contributing to it. The purpose of this study is to determine whether the methods used in determining the flowpaths of small watersheds are applicable in a large-scale watershed. The two sites being studied are in the Mt. Mansfield region of Vermont. They are the Ranch Brook (9.6km2) and West Branch (11.7km2) watersheds. The techniques being implemented include the isotopic characterization of streamwater samples following a precipitation event, basic streamwater chemistry data and their relationship to stream discharge, and the determination of endmembers to the overall streamwater chemistry. Analysis of stream chemistry data suggests that up to three end members contribute to run-off production in both watersheds. A second aspect of this study is a comparison of the two watersheds. These watersheds are similar in all aspects except for the amount of development within each. Ranch Brook is undeveloped forestland while West Branch encompasses an alpine ski resort. Elevated chloride concentrations in the managed watershed suggest the possibility of contamination due to the application of road-salt. Initial oxygen isotope data suggests different flowpath patterns during snowmelt events, which may be the result of the impacts of ski trails and artificial snow on the West Branch site. These two sites provide the unique opportunity to determine impacts of ski development on the streamwater chemistry of alpine watersheds. Future plans include sampling of potential end members such as soilwater, groundwater and snowpack and analysis of additional isotopic data in order to constrain our assessment of flowpaths contributing to the runoff in these basins.

  15. A Modeling Approach Across Length Scales for Progressive Failure Analysis of Woven Composites

    Science.gov (United States)

    Mao, J. Z.; Sun, X. S.; Ridha, M.; Tan, V. B. C.; Tay, T. E.

    2013-06-01

    This paper presents a multiscale modeling approach for the progressive failure analysis of carbon-fiber-reinforced woven composite materials. Hierarchical models of woven composites at three different length scales (micro, meso, and macro) were developed according to their unique geometrical and material characteristics. A novel strategy of two-way information transfer is developed for the multiscale analysis of woven composites. In this strategy, the macroscopic effective material properties are obtained from property homogenizations at micro and meso scales and the stresses at three length scales are computed with stress amplification method from macroscale to microscale. By means of the two-way information transfer, the micro, meso and macro structural characterizations of composites are carried out so that the micromechanisms of damage and their interactions are successfully investigated in a single macro model. In addition, both the nucleation and growth of damages are tracked during the progressive failure analysis. A continuum damage mechanics (CDM) method is used for post-failure modeling. The material stiffness, tensile strength and damage patterns of an open-hole woven composite laminate are predicted with the proposed multiscale method. The predictions are in good agreement with the experimental results.

  16. Use of the Progressive Aphasia Severity Scale (PASS) in monitoring speech and language status in PPA.

    Science.gov (United States)

    Sapolsky, Daisy; Domoto-Reilly, Kimiko; Dickerson, Bradford C

    2014-01-01

    Primary progressive aphasia (PPA) is a devastating neurodegenerative syndrome involving the gradual development of aphasia, slowly impairing the patient's ability to communicate. Pharmaceutical treatments do not currently exist and intervention often focuses on speech-language behavioral therapies, although further investigation is warranted to determine how best to harness functional benefits. Efforts to develop pharmaceutical and behavioral treatments have been hindered by a lack of standardized methods to monitor disease progression and treatment efficacy. Here we describe our current approach to monitoring progression of PPA, including the development and applications of a novel clinical instrument for this purpose, the Progressive Aphasia Severity Scale (PASS). We also outline some of the issues related to initial evaluation and longitudinal monitoring of PPA. In our clinical and research practice we perform initial and follow-up assessments of PPA patients using a multi-faceted approach. In addition to standardized assessment measures, we use the PASS to rate presence and severity of symptoms across distinct domains of speech, language, and functional and pragmatic aspects of communication. Ratings are made using the clinician's best judgment, integrating information from patient test performance in the office as well as a companion's description of routine daily functioning. Monitoring symptom characteristics and severity with the PASS can assist in developing behavioral therapies, planning treatment goals, and counseling patients and families on clinical status and prognosis. The PASS also has potential to advance the implementation of PPA clinical trials. PPA patients display heterogeneous language profiles that change over time given the progressive nature of the disease. The monitoring of symptom progression is therefore crucial to ensure that proposed treatments are appropriate at any given stage, including speech-language therapy and potentially

  17. Chemistry and materials science progress report. Weapons-supporting research and laboratory directed research and development: FY 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-01

    This report covers different materials and chemistry research projects carried out a Lawrence Livermore National Laboratory during 1995 in support of nuclear weapons programs and other programs. There are 16 papers supporting weapons research and 12 papers supporting laboratory directed research.

  18. The IUPAC International Congresses of Pesticide Chemistry (1963-2014) and Pest Management Science: a half-century of progress.

    Science.gov (United States)

    Brooks, Gerald T

    2014-08-01

    As we approach the 2014 San Francisco IUPAC Pesticide Chemistry Congress, we reflect on the 51 years of such congresses every 4 years since 1963. Meanwhile, our journal, Pesticide Science/Pest Management Science, has in parallel continually published relevant science for nearly as long (44 years from 1970). © 2014 Society of Chemical Industry.

  19. Fiber laser beam combining and power scaling progress: Air Force Research Laboratory Laser Division

    Science.gov (United States)

    Wagner, T. J.

    2012-02-01

    Numerous achievements have been made recently by researchers in the areas of fiber laser beam combining and power scaling. Industry has demonstrated multi-kW power from a single fiber amplifier, and a US national laboratory has coherently combined eight fiber amplifiers totaling 4 kW. This paper will survey the recent literature and then focus on fiber laser results from the Laser Division, Directed Energy Directorate of the Air Force Research Laboratory (AFRL). Progress has been made in the power scaling of narrow-linewidth fiber amplifiers, and we are transitioning lessons learned from PCF power scaling into monolithic architectures. SBS suppression has been achieved using a variety of techniques to lower the Brillioun gain, including acoustically tailored fiber, laser gain competition resulting from multitone seeding and inducing a longitudinal thermal gradient. We recently demonstrated a 32-channel coherent beam combination result using AFRL's phaselocking technique and are focused on exploring the limitations of this technique including linewidth broadening, kW-induced phase nonlinearities and auto-tuning methods for large channel counts. Additionally, we have recently refurbished our High Energy Laser Joint Technology Office-sponsored 16-amplifier fiber testbed to meet strict PER, spatial drift, power stability and beam quality requirements.

  20. Nanometer-Scale Chemistry of a Calcite Biomineralization Template: Implications for Skeletal Composition and Nucleation

    Energy Technology Data Exchange (ETDEWEB)

    Branson, Oscar; Bonnin, Elisa A.; Perea, Daniel E.; Spero, Howard J.; Zhu, Zihua; Winters, Maria; Hönisch, Bärbel; Russell, Ann D.; Fehrenbacher, Jennifer S.; Gagnon, Alexander C.

    2016-10-28

    Biomineralizing organisms exhibit exquisite control over skeletal morphology and composition. The promise of understanding and harnessing this feat of natural engineering has motivated an intense search for the mechanisms that direct in vivo mineral self-assembly. We used atom probe tomography, a sub-nanometer 3D chemical mapping technique, to examine the chemistry of a buried organic-mineral interface in biomineral calcite from a marine foraminifer. The chemical patterns at this interface capture the processes of early biomineralization, when the shape, mineralogy, and orientation of skeletal growth are initially established. Sodium is enriched by a factor of nine on the organic side of the interface. Based on this pattern, we suggest that sodium plays an integral role in early biomineralization, potentially altering interfacial energy to promote crystal nucleation, and that interactions between organic surfaces and electrolytes other than calcium or carbonate could be a crucial aspect of CaCO3 biomineralization.

  1. Construction of a robust, large-scale, collaborative database for raw data in computational chemistry: the Collaborative Chemistry Database Tool (CCDBT).

    Science.gov (United States)

    Chen, Mingyang; Stott, Amanda C; Li, Shenggang; Dixon, David A

    2012-04-01

    A robust metadata database called the Collaborative Chemistry Database Tool (CCDBT) for massive amounts of computational chemistry raw data has been designed and implemented. It performs data synchronization and simultaneously extracts the metadata. Computational chemistry data in various formats from different computing sources, software packages, and users can be parsed into uniform metadata for storage in a MySQL database. Parsing is performed by a parsing pyramid, including parsers written for different levels of data types and sets created by the parser loader after loading parser engines and configurations. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Evaluation of Alzheimer's disease progression based on clinical dementia rating scale with missing responses and covariates.

    Science.gov (United States)

    Das, Kalyan; Rana, Subrata; Roy, Surupa

    2017-11-27

    In clinical trials, patient's disease severity is usually assessed on a Likert-type scale. Patients, however, may miss one or more follow-up visits (non-monotone missing). The statistical analysis of non-Gaussian longitudinal data with non-monotone missingness is difficult to handle, particularly when both response and time-dependent covariates are subject to such missingness. Even when the number of patients with intermittent missing data is small, ignoring those patients from analysis seems to be unsatisfactory. The focus of the current investigation is to study the progression of Alzheimer's disease by incorporating a non-ignorable missing data mechanism for both response and covariates in a longitudinal setup. Combining the cumulative logit longitudinal model for Alzheimer's disease progression with the bivariate binary model for the missing pattern, we develop a joint likelihood. The parameters are then estimated using the Monte Carlo Newton Raphson Expectation Maximization (MCNREM) method. This approach is quite easy to handle and the convergence of the estimates is attained in a reasonable amount of time. The study reveals that apolipo-protein plays a significant role in assessing a patient's disease severity. A detailed simulation has also been carried out for justifying the performance of our approach.

  3. The influence of small-scale variations in isoprene concentrations on atmospheric chemistry over a tropical rainforest

    Directory of Open Access Journals (Sweden)

    T. A. M. Pugh

    2011-05-01

    Full Text Available Biogenic volatile organic compounds (BVOCs such as isoprene constitute a large proportion of the global atmospheric oxidant sink. Their reactions in the atmosphere contribute to processes such as ozone production and secondary organic aerosol formation. However, over the tropical rainforest, where 50 % of the global emissions of BVOCs are believed to occur, atmospheric chemistry models have been unable to simulate concurrently the measured daytime concentration of isoprene and that of its principal oxidant, hydroxyl (OH. One reason for this model-measurement discrepancy may be incomplete mixing of isoprene within the convective boundary layer, leading to patchiness or segregation in isoprene and OH mixing ratios and average concentrations that appear to be incompatible with each other. One way of capturing this effect in models of atmospheric chemistry is to use a reduced effective rate constant for their reaction. Recent studies comparing atmospheric chemistry global/box models with field measurements have suggested that this effective rate reduction may be as large as 50 %; which is at the upper limit of that calculated using large eddy simulation models. To date there has only been one field campaign worldwide that has reported co-located measurements of isoprene and OH at the necessary temporal resolution to calculate the segregation of these compounds. However many campaigns have recorded sufficiently high resolution isoprene measurements to capture the small-scale fluctuations in its concentration. Assuming uniform distributions of other OH production and loss processes, we use a box model of atmospheric chemistry, constrained by the spectrum of isoprene concentrations measured, as a virtual instrument, to estimate the variability in OH at a point and hence, to estimate the segregation intensity of isoprene and OH from high-frequency isoprene time series. The method successfully reproduces the only directly observed segregation, using

  4. Recent advances in the computational chemistry of soft porous crystals.

    Science.gov (United States)

    Fraux, Guillaume; Coudert, François-Xavier

    2017-06-29

    Here we highlight recent progress in the field of computational chemistry of nanoporous materials, focusing on methods and studies that address the extraordinary dynamic nature of these systems: the high flexibility of their frameworks, the large-scale structural changes upon external physical or chemical stimulation, and the presence of defects and disorder. The wide variety of behavior demonstrated in soft porous crystals, including the topical class of metal-organic frameworks, opens new challenges for computational chemistry methods at all scales.

  5. Progress in Heavy Ion Driven Inertial Fusion Energy: From Scaled Experiments to the Integrated Research Experiment.

    Energy Technology Data Exchange (ETDEWEB)

    Barnard, J J; Ahle, L E; Baca, D; Bangerter, R O; Bieniosek, F M; Celata, C M; Chacon-Golcher, E; Davidson, R C; Faltens, A; Friedman, A; Franks, R M; Grote, D P; Haber, I; Henestroza, E; de Hoon, M J; Kaganovich, I; Karpenko, V P; Kishek, R A; Kwan, J W; Lee, E P; Logan, B G; Lund, S M; Meier, W R; Molvik, W; Olson, C; Prost, L R; Qin, H; Rose, D; Sabbi, G L; Sangster, T C; Seidl, P A; Sharp, W M; Shuman, D; Vay, J L; Waldron, W L; Welch, D; Yu, S S

    2001-07-10

    provide an integrated test of the beam physics necessary for a driver, but in addition will provide target and chamber data. This paper will review the experimental and theoretical progress in heavy ion accelerator driver research from the scaled experiments through the present experiments and will discuss plans for the IRE.

  6. Influence of chemistry and climate on large induced large scale stresses in anisotropically fractured carbonates.

    Science.gov (United States)

    Toussaint, R.; Cornet, F.

    2012-04-01

    We will explore a simple model coupling for carbonate rocks the fracture density and orientation, the water chemistry and transport, the dissolution reactions and the expected irreversible rock deformation. Adding elasticity and boundary conditions, plus an estimation of the water source composition in the formation, we will estimate orders of magnitudes of the stress changes that can be expected from these processes in sedimentary basins over long times. We will in particular examine whether such intrinsic deformation mechanism can give a hint to explain the observed anisotropic stresses, in orientation and magnitude, in zones above the C.O.X. argillite formation in the Paris Basin, where the horizontal stress anisotropy has been shown to be important, whereas stress decoupling from the deep crustal roots should be effective, and no strong anisotropy would be expected in the absence of active deformation mechanism. In the Paris basin, the analysis of log cores shows that fractures and joints, up to meter-long ones, are common anisotropic features present in the carbonate rocks. Dissolution of calcite along these oriented features removes material with an a priori oriented flux reflecting this structural anisotropy, resulting in a non-isotropic deformation associated to this dissolution. We will present a simple model where dissolution and transport of dissolved calcite is associated with the deformation of the carbonate rock. Estimating the reaction constants, the chemical composition variation of the meteoric water, the rock permeability and the fracture density from observations around the Bure underground laboratory, we will estimate the order of magnitude of the deformations expected from these types of mechanisms. Such estimates have already been performed for dissolution along stylolites, e.g. by Clark, 1966; Renard et al., 2004; Schmittbuhl et al., 2004; Koehn et al., 2007. We will adapt these to reflect the anisotropic feature of the fractures present in

  7. Modelling the urban air quality in Hamburg with the new city-scale chemistry transport model CityChem

    Science.gov (United States)

    Karl, Matthias; Ramacher, Martin; Aulinger, Armin; Matthias, Volker; Quante, Markus

    2017-04-01

    Air quality modelling plays an important role by providing guidelines for efficient air pollution abatement measures. Currently, most urban dispersion models treat air pollutants as passive tracer substances or use highly simplified chemistry when simulating air pollutant concentrations on the city-scale. The newly developed urban chemistry-transport model CityChem has the capability of modelling the photochemical transformation of multiple pollutants along with atmospheric diffusion to produce pollutant concentration fields for the entire city on a horizontal resolution of 100 m or even finer and a vertical resolution of 24 layers up to 4000 m height. CityChem is based on the Eulerian urban dispersion model EPISODE of the Norwegian Institute for Air Research (NILU). CityChem treats the complex photochemistry in cities using detailed EMEP chemistry on an Eulerian 3-D grid, while using simple photo-stationary equilibrium on a much higher resolution grid (receptor grid), i.e. close to industrial point sources and traffic sources. The CityChem model takes into account that long-range transport contributes to urban pollutant concentrations. This is done by using 3-D boundary concentrations for the city domain derived from chemistry-transport simulations with the regional air quality model CMAQ. For the study of the air quality in Hamburg, CityChem was set-up with a main grid of 30×30 grid cells of 1×1 km2 each and a receptor grid of 300×300 grid cells of 100×100 m2. The CityChem model was driven with meteorological data generated by the prognostic meteorology component of the Australian chemistry-transport model TAPM. Bottom-up inventories of emissions from traffic, industry, households were based on data of the municipality of Hamburg. Shipping emissions for the port of Hamburg were taken from the Clean North Sea Shipping project. Episodes with elevated ozone (O3) were of specific interest for this study, as these are associated with exceedances of the World

  8. Modeling lightning-NOx chemistry on a sub-grid scale in a global chemical transport model

    Directory of Open Access Journals (Sweden)

    A. Gressent

    2016-05-01

    Full Text Available For the first time, a plume-in-grid approach is implemented in a chemical transport model (CTM to parameterize the effects of the nonlinear reactions occurring within high concentrated NOx plumes from lightning NOx emissions (LNOx in the upper troposphere. It is characterized by a set of parameters including the plume lifetime, the effective reaction rate constant related to NOx–O3 chemical interactions, and the fractions of NOx conversion into HNO3 within the plume. Parameter estimates were made using the Dynamical Simple Model of Atmospheric Chemical Complexity (DSMACC box model, simple plume dispersion simulations, and the 3-D Meso-NH (non-hydrostatic mesoscale atmospheric model. In order to assess the impact of the LNOx plume approach on the NOx and O3 distributions on a large scale, simulations for the year 2006 were performed using the GEOS-Chem global model with a horizontal resolution of 2° × 2.5°. The implementation of the LNOx parameterization implies an NOx and O3 decrease on a large scale over the region characterized by a strong lightning activity (up to 25 and 8 %, respectively, over central Africa in July and a relative increase downwind of LNOx emissions (up to 18 and 2 % for NOx and O3, respectively, in July. The calculated variability in NOx and O3 mixing ratios around the mean value according to the known uncertainties in the parameter estimates is at a maximum over continental tropical regions with ΔNOx [−33.1, +29.7] ppt and ΔO3 [−1.56, +2.16] ppb, in January, and ΔNOx [−14.3, +21] ppt and ΔO3 [−1.18, +1.93] ppb, in July, mainly depending on the determination of the diffusion properties of the atmosphere and the initial NO mixing ratio injected by lightning. This approach allows us (i to reproduce a more realistic lightning NOx chemistry leading to better NOx and O3 distributions on the large scale and (ii to focus on other improvements to reduce remaining uncertainties from processes

  9. Dynamics of ozone and nitrogen oxides at Summit, Greenland. II. Simulating snowpack chemistry during a spring high ozone event with a 1-D process-scale model

    NARCIS (Netherlands)

    Murray, K.A.; Kramer, L.J.; Doskey, P.V.; Ganzeveld, L.N.; Seok, B.; Dam, van B.; Helmig, D.

    2015-01-01

    Observed depth profiles of nitric oxide (NO), nitrogen dioxide (NO2), and ozone (O3) in snowpack interstitial air at Summit, Greenland were best replicated by a 1-D process-scale model, which included (1) geometrical representation of snow grains as spheres, (2) aqueous-phase chemistry confined to a

  10. Using sulfite chemistry for robust bioconversion of Douglas-fir forest residue to bioethanol at high titer and lignosulfonate: A pilot-scale evaluation

    Science.gov (United States)

    J.Y. Zhu; M. Subhosh Chandra; Feng Gu; Roland Gleisner; J.Y. Zhu; John Sessions; Gevan Marrs; Johnway Gao; Dwight Anderson

    2015-01-01

    This study demonstrated at the pilot-scale (50 kg) use of Douglas-fir forest harvest residue, an underutilized forest biomass, for the production of high titer and high yield bioethanol using sulfite chemistry without solid–liquor separation and detoxification. Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL) was directly applied to the...

  11. Description and evaluation of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry model (NMMB-MONARCH) version 1.0: gas-phase chemistry at global scale

    Science.gov (United States)

    Badia, Alba; Jorba, Oriol; Voulgarakis, Apostolos; Dabdub, Donald; Pérez García-Pando, Carlos; Hilboll, Andreas; Gonçalves, María; Janjic, Zavisa

    2017-02-01

    This paper presents a comprehensive description and benchmark evaluation of the tropospheric gas-phase chemistry component of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry model (NMMB-MONARCH), formerly known as NMMB/BSC-CTM, that can be run on both regional and global domains. Here, we provide an extensive evaluation of a global annual cycle simulation using a variety of background surface stations (EMEP, WDCGG and CASTNET), ozonesondes (WOUDC, CMD and SHADOZ), aircraft data (MOZAIC and several campaigns), and satellite observations (SCIAMACHY and MOPITT). We also include an extensive discussion of our results in comparison to other state-of-the-art models. We note that in this study, we omitted aerosol processes and some natural emissions (lightning and volcano emissions). The model shows a realistic oxidative capacity across the globe. The seasonal cycle for CO is fairly well represented at different locations (correlations around 0.3-0.7 in surface concentrations), although concentrations are underestimated in spring and winter in the Northern Hemisphere, and are overestimated throughout the year at 800 and 500 hPa in the Southern Hemisphere. Nitrogen species are well represented in almost all locations, particularly NO2 in Europe (root mean square error - RMSE - below 5 ppb). The modeled vertical distributions of NOx and HNO3 are in excellent agreement with the observed values and the spatial and seasonal trends of tropospheric NO2 columns correspond well to observations from SCIAMACHY, capturing the highly polluted areas and the biomass burning cycle throughout the year. Over Asia, the model underestimates NOx from March to August, probably due to an underestimation of NOx emissions in the region. Overall, the comparison of the modeled CO and NO2 with MOPITT and SCIAMACHY observations emphasizes the need for more accurate emission rates from anthropogenic and biomass burning sources (i.e., specification of temporal variability). The resulting

  12. Compilation and analyses of emissions inventories for NOAA`s atmospheric chemistry project. Progress report, August 1997

    Energy Technology Data Exchange (ETDEWEB)

    Benkovitz, C.M.; Mubaraki, M.A.

    1997-09-01

    Global inventories of anthropogenic emissions of oxides of nitrogen (NO{sub x}) for circa 1985 and 1990 and Non-Methane Volatile Organic Compounds (NMVOCs) for circa 1990 have been compiled by this project. Work on the inventories has been carried out under the umbrella of the Global Emissions Inventory Activity (GEIA) of the International Global Atmospheric Chemistry (IGAC) Program. The 1985 NO{sub x} inventory was compiled using default data sets of global emissions that were refined via the use of more detailed regional data sets; this inventory is being distributed to the scientific community at large as the GEIA Version 1A inventory. Global emissions of NO{sub x} for 1985 are estimated to be 21 Tg N y{sup -1}, with approximately 84% originating in the Northern Hemisphere. The 1990 inventories of NO{sub x} and NMVOCs were compiled using unified methodologies and data sets in collaboration with the Netherlands National Institute of Public Health and Environmental Protection (Rijksinstituut Voor Volksgezondheid en Milieuhygiene, RIVM) and the Division of Technology for Society of the Netherlands Organization for Applied Scientific Research, (IMW-TNO); these emissions will be used as the default estimates to be updated with more accurate regional data. The NMVOC inventory was gridded and speciated into 23 chemical categories.

  13. Superacid Catalyzed Coal Conversion Chemistry. 1st and 2nd Quarterly Technical Progress Reports, September 1, 1983-March 30, 1984.

    Science.gov (United States)

    Olah, G. A.

    1984-01-01

    In our laboratories we have previously developed a mild coal conversion process. This involves the use of a superacid system consisting of HF and BF{sub 3} in presence of hydrogen and/or a hydrogen donor solvent. In order to understand the chemistry involved in the process of depolymerization of coal by the HF:BF{sub 3}:H{sub 2} system we are carrying out a systematic study of a number of coal model compounds. The model compounds selected for present study have two benzene rings connected with various bridging units such as alkylidene, ether, sulfide etc. From studies so far carried out it appears that high pyridine extractibilities achieved by treating coal at temperature below 100 degrees C results from the cleavage of bridges such as present in bibenzyl, diphenyl methane, dibenzyl ether, dibenzyl sulfide etc. On the other hand the increased cyclohexane extractibility and distillability observed at relatively higher temperatures and hydrogen pressures reflects the hydrogenation and cleavage of the aromatic backbone in coal structure similar to what is seen in the conversion of model compounds such as biphenyl, diphenyl ether, diphenyl sulfide, anthracene, etc.

  14. Progression to multi-scale models and the application to food system intervention strategies.

    Science.gov (United States)

    Gröhn, Yrjö T

    2015-02-01

    The aim of this article is to discuss how the systems science approach can be used to optimize intervention strategies in food animal systems. It advocates the idea that the challenges of maintaining a safe food supply are best addressed by integrating modeling and mathematics with biological studies critical to formulation of public policy to address these challenges. Much information on the biology and epidemiology of food animal systems has been characterized through single-discipline methods, but until now this information has not been thoroughly utilized in a fully integrated manner. The examples are drawn from our current research. The first, explained in depth, uses clinical mastitis to introduce the concept of dynamic programming to optimize management decisions in dairy cows (also introducing the curse of dimensionality problem). In the second example, a compartmental epidemic model for Johne's disease with different intervention strategies is optimized. The goal of the optimization strategy depends on whether there is a relationship between Johne's and Crohn's disease. If so, optimization is based on eradication of infection; if not, it is based on the cow's performance only (i.e., economic optimization, similar to the mastitis example). The third example focuses on food safety to introduce risk assessment using Listeria monocytogenes and Salmonella Typhimurium. The last example, practical interventions to effectively manage antibiotic resistance in beef and dairy cattle systems, introduces meta-population modeling that accounts for bacterial growth not only in the host (cow), but also in the cow's feed, drinking water and the housing environment. Each example stresses the need to progress toward multi-scale modeling. The article ends with examples of multi-scale systems, from food supply systems to Johne's disease. Reducing the consequences of foodborne illnesses (i.e., minimizing disease occurrence and associated costs) can only occur through an

  15. Effectiveness of scaling up the 'three pillars' approach to accelerating MDG 4 progress in Ethiopia.

    Science.gov (United States)

    Carnell, Mary A; Dougherty, Leanne; Pomeroy, Amanda M; Karim, Ali M; Mekonnen, Yared M; Mulligan, Brian E

    2014-12-01

    This paper describes the integrated approach taken by the Government of Ethiopia with support from the Essential Services for Health in Ethiopia (ESHE) Project and assesses its effect on the coverage of six child health practices associated with reducing child mortality. The ESHE Project was designed to contribute to reducing high child mortality rates at scale among 14.5 million people through the 'three pillars' approach. This approach aimed to (i) strengthen health systems, (ii) improve health workers' performance, and (iii) engage the community. The intervention was designed with national and subnational stakeholders' input. To measure the Project's effect on the coverage of child health practices, we used a quasi-experimental design, with representative household survey data from the three most populous regions of Ethiopia, collected at the 2003-2004 baseline and 2008 endline surveys of the Project. Adifference-in-differences analysis model detected an absolute effect of the ESHE intervention of 8.4% points for DTP3 coverage (p=0.007), 12.9% points for measles vaccination coverage (p<0.001), 12.6% points for latrines (p=0.002), and 9.8% points for vitamin A supplementation (p<0.001) across the ESHE-intervention districts (woredas) compared to all non-ESHE districts of the same three regions. Improvements in the use of modern family planning methods and exclusive breastfeeding were not significant. Important regional variations are discussed. ESHE was one of several partners of the Ministry of Health whose combined efforts led to accelerated progress in the coverage of child health practices.

  16. Influence of mercury and selenium chemistries on the progression of cardiomyopathy in pygmy sperm whales, Kogia breviceps.

    Science.gov (United States)

    Bryan, Colleen E; Davis, W Clay; McFee, Wayne E; Neumann, Carola A; Schulte, Jennifer; Bossart, Gregory D; Christopher, Steven J

    2012-10-01

    More than half of pygmy sperm whales (Kogia breviceps) that strand exhibit signs of cardiomyopathy (CMP). Many factors may contribute to the development of idiopathic CMP in K. breviceps, including genetics, infectious agents, contaminants, biotoxins, and dietary intake (e.g. selenium, mercury, and pro-oxidants). This study assessed trace elements in K. breviceps at various stages of CMP progression using fresh frozen liver and heart samples collected from individuals that stranded along US Atlantic and Gulf coasts between 1993 and 2007. Standard addition calibration and collision cell inductively coupled plasma mass spectrometry (ICP-MS) were employed for total Se analysis and pyrolysis atomic absorption (AA) was utilized for total Hg analysis to examine if the Se/Hg detoxification pathway inhibits the bioavailability of Se. Double spike speciated isotope dilution gas chromatography ICP-MS was utilized to measure methyl Hg and inorganic Hg. Immunoblot detection and colorimetric assays were used to assess protein oxidation status. Data collected on trace elements, selenoproteins, and oxidative status were evaluated in the context of animal life history and other complementary histological information to gain insight into the biochemical pathways contributing to the development of CMP in K. breviceps. Cardiomyopathy was only observed in adult pygmy sperm whales, predominantly in male animals. Both Hg:Se molar ratios and overall protein oxidation were greater in males than females and increased with progression of CMP. Published by Elsevier Ltd.

  17. Finding the Connections between a High-School Chemistry Curriculum and Nano-Scale Science and Technology

    Science.gov (United States)

    Blonder, Ron; Sakhnini, Sohair

    2017-01-01

    The high-school chemistry curriculum is loaded with many important chemical concepts that are taught at the high-school level and it is therefore very difficult to add modern contents to the existing curriculum. However, many studies have underscored the importance of integrating modern chemistry contents such as nanotechnology into a high-school…

  18. A Global Scale Scenario for Prebiotic Chemistry: Silica-Based Self-Assembled Mineral Structures and Formamide

    Science.gov (United States)

    2016-01-01

    membrane are clearly specific, demonstrating that the mineral self-assembled membranes at the same time create space compartmentalization and selective catalysis of the synthesis of relevant compounds. Rather than requiring odd local conditions, the prebiotic organic chemistry scenario for the origin of life appears to be common at a universal scale and, most probably, earlier than ever thought for our planet. PMID:27115539

  19. From C60 to Infinity: Large-Scale Quantum Chemistry Calculations of the Heats of Formation of Higher Fullerenes.

    Science.gov (United States)

    Chan, Bun; Kawashima, Yukio; Katouda, Michio; Nakajima, Takahito; Hirao, Kimihiko

    2016-02-03

    We have carried out large-scale computational quantum chemistry calculations on the K computer to obtain heats of formation for C60 and some higher fullerenes with the DSD-PBE-PBE/cc-pVQZ double-hybrid density functional theory method. Our best estimated values are 2520.0 ± 20.7 (C60), 2683.4 ± 17.7 (C70), 2862.0 ± 18.5 (C76), 2878.8 ± 13.3 (C78), 2946.4 ± 14.5 (C84), 3067.3 ± 15.4 (C90), 3156.6 ± 16.2 (C96), 3967.7 ± 33.4 (C180), 4364 (C240) and 5415 (C320) kJ mol(-1). In our assessment, we also find that the B3-PW91-D3BJ and BMK-D3(BJ) functionals perform reasonably well. Using the convergence behavior for the calculated per-atom heats of formation, we obtained the formula ΔfH per carbon = 722n(-0.72) + 5.2 kJ mol(-1) (n = the number of carbon atoms), which enables an estimation of ΔfH for higher fullerenes more generally. A slow convergence to the graphene limit is observed, which we attribute to the relatively small proportion of fullerene carbons that are in "low-strain" regions. We further propose that it would take tens, if not hundreds, of thousands of carbons for a fullerene to roughly approach the limit. Such a distinction may be a contributing factor to the discrete properties between the two types of nanomaterials. During the course of our study, we also observe a fairly reliable means for the theoretical calculation of heats of formation for medium-sized fullerenes. This involves the use of isodesmic-type reactions with fullerenes of similar sizes to provide a good balance of the chemistry and to minimize the use of accompanying species.

  20. Birth, growth and progresses through the last twelve years of a regional scale landslide warning system

    Science.gov (United States)

    Fanti, Riccardo; Segoni, Samuele; Rosi, Ascanio; Lagomarsino, Daniela; Catani, Filippo

    2017-04-01

    recordings and landslides occurred) and to use them to define more robust relationships between rainfalls and landslide triggering, with the final aim to increase the forecasting effectiveness of the warning system. The updated rainfall and landslide database were used to periodically perform a quantitative validation and to analyze the errors affecting the system forecasts. The errors characterization was used to implement a continuous process of updating and modification of SIGMA, that included: - Main model upgrades (generalization from a pilot test site to the whole Emilia Romagna region; calibration against well documented landslide events to define specific σ levels for each territorial units; definition of different alert levels according to the number of expected - Ordinary updates (periodically, the new landslide and rainfall data were used to re-calibrate the thresholds, taking into account a more robust sample). - Model tuning (set up of the optimal version of the decisional algorithm, including different definitions of "long" and "short" periods; selection of the optimal reference rain gauge for each Territorial Unit; modification of the boundaries of some territorial - Additional features (definition of a module that takes into account the effect of snow melt and snow accumulation; coupling with a landslide susceptibility model to improve the spatial accuracy of the model). - Various performance tests (including the comparison with alternate versions of SIGMA or with thresholds based on rainfall intensity and duration). This process has led to an evolution of the warning system and to a documented improvement of its forecasting effectiveness. Landslide forecasting at regional scale is a very complex task, but as time passes by and with the systematic gathering of new substantial data and the continuous progresses of research, uncertainties can be progressively reduced and a warning system can be set that increases its performances and reliability with time.

  1. Applications of molecular quantum mechanics to problems in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, H.F. III

    1983-03-01

    The past decade has witnessed remarkable progress in the development of rigorous quantum mechanical methods for the study of molecular electronic structure. Key developments include the emergence of large scale configuration interaction methods (including more than one million variational parameters) and of analytic first and second energy derivative techniques. These advances have greatly increased the scope of current applications of quantun mechanics to chemistry. Present and anticipated future developments with respect to the fields of physical, organic, and inorganic chemistry are surveyed.

  2. Planar interfaces: Synthesis and high resolution chemistry and structure analysis. Progress report, March 1, 1997--February 28, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, R.W.; Kim, M.J.

    1998-04-01

    The interface synthesis unit is operational and working well. The authors have synthesized interfaces between substrates of austenitic stainless steel, silicon, silicon/niobium, and alumina with and without addition of other materials in the interfaces. Early in the synthesis work it was apparent that substrate surface preparation was critical, along with the usual variables: temperature, time, and pressure. After suitable surface preparation successful interfaces were bonded. Substrate surface preparation requires surface cleaning, to activate the surface and polishing to flatten the bonding surfaces. Flatness has two components: large scale flatness and short wavelength near atomic scale flatness. Analytical TEM electron energy loss (ELS) and energy dispersive x-ray (EDS) nanospectroscopies showed that no detectable oxygen contamination occurred in any of the interfaces they have synthesized, in particular in the stainless steel interfaces containing Ti or Cu. Those two interfaces were especially stringent tests of the synthesis unit because of the high reactivity of Ti and Cu with oxygen. Single crystal Si {l_brace}100{r_brace} substrates are more useful than polycrystalline stainless steel for determining the effect of ion cleaning induced roughness on interface morphology. Nb was deposited at room temperature on ion-cleaned and as-received Si wafers to evaluate this effect in edge-on transmission geometry. The authors have extended their work on contacts for GaN to TiN/GaN interfaces and Au/Ti/GaN multilayer interfaces. Some recent results from the GaN contact research are given in Smith et. al. (1996a) and Smith et. al. (1996b). The authors have evaluated the usefulness of one of the new oxygen plasma cleaning units for prevention of carbonaceous contamination build-up on TEM specimens. It proved very successful.

  3. Advanced solids NMR studies of coal structure and chemistry. Progress report, September 1, 1995--February 28, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Zilm, K.W.

    1996-09-01

    This report covers the progress made on the title project for the project period. The study of coal chemical structure is a vital component of research efforts to develop better chemical utilization of coals, and for furthering our basic understanding of coal geochemistry. In this grant we are addressing several structural questions pertaining to coals with advances in state of the art solids NMR methods. Our goals are twofold. First, we are interested in developing new methods that will enable us to measure important structural parameters in whole coals not directly accessible by other techniques. In parallel with these efforts we will apply these NMR methods in a study of the chemical differences between gas-sourcing and oil-sourcing coals. The NMR methods work will specifically focus on determination of the number and types of methylene groups, determination of the number and types of methine groups, identification of carbons adjacent to nitrogen and sites with exchangeable protons, and methods to more finely characterize the distribution of hydrogen in coals. We will also develop NMR methods for probing coal macropore structure using hyperpolarized {sup 129}Xe as a probe, and study the molecular dynamics of what appear to be mobile, CH{sub 2} rich, long chain hydrocarbons. The motivation for investigating these specific structural features of coals arises from their relevance to the chemical reactivity of some types of coals. The coals to be studied and contrasted include oil-prone coals from Australia and Indonesia, those comprising the Argonne Premium Coal Sample bank, and other relevant samples.

  4. Description and Evaluation of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry Model (NMMB-MONARCH) Version 1.0: Gas-Phase Chemistry at Global Scale

    Science.gov (United States)

    Badia, Alba; Jorba, Oriol; Voulgarakis, Apostolos; Dabdub, Donald; Garcia-Pando, Carlos Perez; Hilboll, Andreas; Goncalves, Maria; Janjic, Zavisa

    2017-01-01

    This paper presents a comprehensive description and benchmark evaluation of the tropospheric gas-phase chemistry component of the Multiscale Online Nonhydrostatic AtmospheRe CHemistry model (NMMBMONARCH), formerly known as NMMB/BSC-CTM, that can be run on both regional and global domains. Here, we provide an extensive evaluation of a global annual cycle simulation using a variety of background surface stations (EMEP, WDCGG and CASTNET), ozonesondes (WOUDC, CMD and SHADOZ), aircraft data (MOZAIC and several campaigns), and satellite observations (SCIAMACHY and MOPITT).We also include an extensive discussion of our results in comparison to other state-of-the-art models. We note that in this study, we omitted aerosol processes and some natural emissions (lightning and volcano emissions). The model shows a realistic oxidative capacity across the globe. The seasonal cycle for CO is fairly well represented at different locations (correlations around 0.3-0.7 in surface concentrations), although concentrations are underestimated in spring and winter in the Northern Hemisphere, and are overestimated throughout the year at 800 and 500 hPa in the Southern Hemisphere. Nitrogen species are well represented in almost all locations, particularly NO2 in Europe (root mean square error - RMSE - below 5 ppb). The modeled vertical distributions of NOx and HNO3 are in excellent agreement with the observed values and the spatial and seasonal trends of tropospheric NO2 columns correspond well to observations from SCIAMACHY, capturing the highly polluted areas and the biomass burning cycle throughout the year. Over Asia, the model underestimates NOx from March to August, probably due to an underestimation of NOx emissions in the region. Overall, the comparison of the modeled CO and NO2 with MOPITT and SCIAMACHY observations emphasizes the need for more accurate emission rates from anthropogenic and biomass burning sources (i.e., specification of temporal variability).

  5. Chemistry and structure of coal-derived asphaltenes, Phase III. Quarterly progress report, July--September 1978

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.

    1978-01-01

    Preparative scale GPC separation of Synthoil asphaltene was carried out on styrene-divinyl benzene packing (Bio-Beads S-X8). The elution took place in the order of high to low molecular weight. Analyses indicate that aromatic ring systems with large saturated substituents elute first followed by more aromatic molecules with less saturated substituents. Infrared measurements on coal-derived asphaltenes were carried out with a large path cell (1 cm) in order to measure absorbance as a function of concentration in dilute solution down to 0.3 g/l where association between asphaltenes is not significant. VPO molecular weight studies indicate that coal-derived oils and resins undergo very little association in the solvent THF in the range 4 to 30 g/l in contrast to coal-derived asphaltenes and benzene insolubles. Thermal treatment of a Synthoil Coal liquid solvent fraction (oil + resin), in tetralin (1:2 wt. ratio) at 232/sup 0/C for 20 h resulted in the transformation of 3 to 10% of the oil + resin into asphaltene. These results support the proposed reversibility of coal liquefaction steps. Pryolysis of coal-derived asphaltenes has been shown to produce residues that are characteristic of coalesced mesophase. Asphaltenes from three liquefaction processes, Catalytic Incorporatd SRC, Synthoil, and FMC-COED, were pyrolyzed under a nitrogen atmosphere at 20/sup 0/C/h to 360/sup 0/C and at 5/sup 0/C/h to 420/sup 0/C. Crossed polarized light reflection micrographs showed a coarse deformed structure for Synthoil asphaltene, a course, but not deformed structure for Catalytic Inc. asphaltne, and a fine isotropic structure for FMC-COED asphaltene.

  6. Experimental determination of contaminant metal mobility as a function of temperature, time and solution chemistry. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, S.; Bruton, C. [Lawrence Livermore National Lab., CA (US); O' Day, P.; Sahai, N. [Arizona State Univ., Tempe, AZ (US)

    1997-01-01

    'Strontium is significantly more mobile than other hazardous radioactive metals. Its partitioning between aqueous and solid phases is controlled by reactions that occur at the interface between natural waters and minerals. At a groundwater site in Hanford (200-BP-5), the aerial extent of the {sup 90}Sr plume is 100 times larger than the aerial extent of the {sup 137}Cs and the {sup 239}Pu plumes. Similarly, contaminated, perched watertables at INEL have much higher aqueous concentrations of {sup 90}Sr than {sup 137}Cs, presumably because Cs is preferentially sorbed to solids (Duncan 1995). Under high physical flow conditions, such as those in the highly fractured rock at Hanford and INEL, {sup 90}Sr present in plumes may spread off-site and cause contamination of aquifers or other water sources. Geochemical factors that may contribute to the overall mobility of Sr in natural waters are the solubilities of phases such as strontianite (SrCO{sub 3}) and formation of strong complexes with sulfate and nitrate. Although {sup 90}Sr is mobilized in natural waters in these examples, significant concentrations may also be present in solid phases. Sorption experiments using a wide variety of substrates at room temperature have shown that Sr is removed from solution under certain conditions. Additionally, strontianite (SrCO{sub 3}) may precipitate at low Sr concentrations in the pH range of waters in contact with basaltic rocks, which varies between pH 8 and 10. Waters contain variable amounts of carbonate owing to atmospheric interactions; the partial pressure of CO{sub 2} is about 10 x 3.5 atm in air and commonly as high as 10 x 2.5 atm in soils. The objective of this work is to determine the fundamental data needed to predict the behavior of strontium at temperature and time scales appropriate to thermal remediation. The authors approach combines macroscopic sorption/precipitation and desorption/dissolution kinetic experiments, which track changes in solution

  7. Measuring Progress in Deaf-Blind Children: Use of the "Azusa Scale".

    Science.gov (United States)

    Stillman, Robert D.

    Evaluated was the use of the Azusa developmental scale with 16 deaf blind children in a completed study and 124 deaf blind children in an ongoing study to determine the scale's usefulness for objective evaluation of behavior change, instructional planning, and program evaluation. The children in the first study were rated on the performance…

  8. HISTOPATHOLOGICAL SCALE AND SYNOVITIS ALGORITHM – 15 YEARS OF EXPERIENCE: EVALUATION AND FOLLOWING PROGRESS

    Directory of Open Access Journals (Sweden)

    V. Krenn

    2017-01-01

    Full Text Available The diagnostic  histopathology scales are mainly  the  multilevel  evaluation systems. The same principle  is lying in the  basis of synovitis  scale elaboration. This  scale gradually  and  semi-quantitatively assesses the  inflammatory and immunological changes in case of synovitis  considering  three  synovial components: thickness  of synovial cellular layer, cellular  stroma  density  and  severity  of inflammatory infiltration. The  scale comprises  four semi-quantitative  grades: normal 0, mild, moderate  and severe. Scale points from 0 to 9 are summated. Such sum evaluation allows to identify high and low degree synovitis.  Scale points  from 1 to ≤4 correspond to low degree synovitis  which determines and includes the following diagnosis: arthritis associated  synovitis;  synovitis  associated  with  meniscus  pathology;  hemochromatosis associated  synovitis.  Scale points  from ≥5 to  9 determine high  degree  synovitis  including  diagnosis  like rheumatoid arthritis; psoriatic  arthritis; Lyme arthritis; post  infection  (reactive arthritis and  peripheral arthritis in Bekhterev’s disease. Thus, the synovitis scale allows to assess degenerative or posttraumatic (low degree synovitis and inflammatoryrheumatoid pathology  (high  degree  synovitis based  on histopathological diagnostics with  sensitivity of 61,7% and specificity  of 96,1%. The scale is characterized by a good diagnostics significance  by ROC  analysis (area  under  curve: 0,8–0,9.  Two versions of synovitis  scale was published:  first in 2002, second reworked  in 2006 and the latter includes the concept  of subdivision  into two groups of high and low degree synovitis.  Thanking to both  versions a national  and international recognition of histological  evaluation during  15 years was gained.   To clarity  diagnosis description using synovitis  scale particularly in rheumatology various

  9. Progress report 1965. Nuclear chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Carleson, G.

    1966-04-15

    Isotopic hydrogen-deuterium effects down to eutectic temperatures in saturated halide and nitrate solutions have been investigated by means of Rayleigh distillations and solubility determinations. A thorough study of the fission-fragment-induced emission of uranium atoms from uranium metal and dioxide has been concluded. Supplementary and new experiments were performed in various atmospheres and at different pressures, and the results and mechanism theoretically interpreted. In order to study the energy transfer mechanism the heterogeneous system n-hexane/silica gel was irradiated with a y-ray source. The products formed were identified by gas chromatography and ESR spectroscopy and their G-values determined. New and efficient methods of separating mixed fission products from an acid and highly active waste solution containing large amounts of uranyl nitrate are required for the reprocessing of plutonium-enriched fuel elements by amine extraction. As part of a project to achieve this separation by eutectic freezing the ternary phase diagram of simulated waste solution was studied and solubilities were determined at low temperatures. Work on the separation of fission products of interest by means of inorganic ion exchangers has also been carried out. The properties and affinities of zirconium phosphates and zirconium silicate phosphates were studied. It was shown that high loads of caesium may be selectively sorbed on partially dehydrated zirconium phosphate gels.

  10. Revisiting the generalized scaling law for adhesion: role of compliance and extension to progressive failure.

    Science.gov (United States)

    Mojdehi, Ahmad R; Holmes, Douglas P; Dillard, David A

    2017-10-25

    A generalized scaling law, based on the classical fracture mechanics approach, is developed to predict the bond strength of adhesive systems. The proposed scaling relationship depends on the rate of change of debond area with compliance, rather than the ratio of area to compliance. This distinction can have a profound impact on the expected bond strength of systems, particularly when the failure mechanism changes or the compliance of the load train increases. Based on the classical fracture mechanics approach for rate-independent materials, the load train compliance should not affect the force capacity of the adhesive system, whereas when the area to compliance ratio is used as the scaling parameter, it directly influences the bond strength, making it necessary to distinguish compliance contributions. To verify the scaling relationship, single lap shear tests were performed for a given pressure sensitive adhesive (PSA) tape specimens with different bond areas, number of backing layers, and load train compliance. The shear lag model was used to derive closed-form relationships for the system compliance and its derivative with respect to the debond area. Digital image correlation (DIC) is implemented to verify the non-uniform shear stress distribution obtained from the shear lag model in a lap shear geometry. The results obtained from this approach could lead to a better understanding of the relationship between bond strength and the geometry and mechanical properties of adhesive systems.

  11. Newton iterative methods for large scale nonlinear systems. Progress report, 1992--1993

    Energy Technology Data Exchange (ETDEWEB)

    Walker, H.F.; Turner, K.

    1993-06-01

    Objective is to develop robust, efficient Newton iterative methods for general large scale problems well suited for discretizations of partial differential equations, integral equations, and other continuous problems. A concomitant objective is to develop improved iterative linear algebra methods. We first outline research on Newton iterative methods and then review work on iterative linear algebra methods. (DLC)

  12. Progressive atrophic rhinitis in a medium-scale pig farm in Kiambu, Kenya : case report

    Directory of Open Access Journals (Sweden)

    J.K. Wabacha

    2000-07-01

    Full Text Available Forty-two pigs in a herd of 117 displayed various clinical signs of progressive atrophic rhinitis. The main signs included sneezing, coughing, lachrymation, serous to muco-purulent nasal discharge, and nasal bleeding in 1 pig. Three pigs had lateral deviation of the snout, while 4 had brachygnathia superior with obvious deformation of the face. Four acutely affected weaner pigs appeared weak, while the 7 chronically-affected pigs appeared smaller than their apparently unaffected penmates of the same age. Treatment of the acutely affected pigs with long-acting oxytetracycline at 20 mg/kg body weight intra-muscularly, repeated once after 7 days, reduced the severity but did not clear the sneezing from all the pigs. Fifteen pigs were slaughtered 2 months after the clinical diagnosis was made. The carcasses of the chronically affected pigs were about 15 % lighter than those of the apparently normal pigs of the same age and from the same pen, which translated to a loss of 921.00 Kenya shillings per pig (US$13.7. Diagnosis of progressive atrophic rhinitis was confirmed by sectioning the snouts of randomly selected slaughtered pigs with obvious deformation of the snout. Sections were madeat the level of the 1st/2nd upper premolar tooth. Varying degrees of turbinate atrophy, from mild to complete, were noted. Histopathology of the turbinates revealed metaplasia of nasal epithelium and fibrosis in the lamina propria.

  13. Bench scale testing of micronized magnetite beneficiation. Quarterly technical progress report 4, October--December, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Anast, K.

    1994-01-25

    This project is aimed at development of a process that, by using ultra fine magnetite suspension, would expand the application of heavy media separation technology to processing fine, {minus}28 mesh coals. These coal fines, produced during coal mining and crushing, are separated in the conventional coal preparation plant and generally impounded in a tailings pond. Development of an economic process for processing these fines into marketable product will expand the utilization of coal for power production in an environmentally acceptable and economically viable way. This process has been successfully researched at PETC but has not been studied on a continuous bench-scale unit, which is a necessary step towards commercial development of this promising technology. The goal of the program is to investigate the technology in a continuous circuit at a reasonable scale to provide a design basis for larger plants and a commercial feasibility data.

  14. dV/dt - Accelerating the Rate of Progress towards Extreme Scale Collaborative Science

    Energy Technology Data Exchange (ETDEWEB)

    Livny, Miron [Univ. of Wisconsin, Madison, WI (United States)

    2018-01-22

    This report introduces publications that report the results of a project that aimed to design a computational framework that enables computational experimentation at scale while supporting the model of “submit locally, compute globally”. The project focuses on estimating application resource needs, finding the appropriate computing resources, acquiring those resources,deploying the applications and data on the resources, managing applications and resources during run.

  15. [Supporting the progress of preterm babies with breastfeeding due to a behavior scale].

    Science.gov (United States)

    Petit, Isabelle; Grattepanche, Catherine

    2012-01-01

    Preterm babies' breastfeeding skills vary from one child to the next, but they can develop very early. Knowledge around this subject now allows each mother and baby to be given individualized support on the long and difficult road from the feeding tube to the breast. The adaptation of the Preterm Infant Breastfeeding Behavior Scale into a diagram provides a visual assessment of the baby's skills.

  16. The Effect of Scale Dependent Discretization on the Progressive Failure of Composite Materials Using Multiscale Analyses

    Science.gov (United States)

    Ricks, Trenton M.; Lacy, Thomas E., Jr.; Pineda, Evan J.; Bednarcyk, Brett A.; Arnold, Steven M.

    2013-01-01

    A multiscale modeling methodology, which incorporates a statistical distribution of fiber strengths into coupled micromechanics/ finite element analyses, is applied to unidirectional polymer matrix composites (PMCs) to analyze the effect of mesh discretization both at the micro- and macroscales on the predicted ultimate tensile (UTS) strength and failure behavior. The NASA code FEAMAC and the ABAQUS finite element solver were used to analyze the progressive failure of a PMC tensile specimen that initiates at the repeating unit cell (RUC) level. Three different finite element mesh densities were employed and each coupled with an appropriate RUC. Multiple simulations were performed in order to assess the effect of a statistical distribution of fiber strengths on the bulk composite failure and predicted strength. The coupled effects of both the micro- and macroscale discretizations were found to have a noticeable effect on the predicted UTS and computational efficiency of the simulations.

  17. Progress toward understanding the distribution of Accumulibacter among full-scale enhanced biological phosphorus removal systems.

    Science.gov (United States)

    He, Shaomei; Gu, April Z; McMahon, Katherine D

    2008-02-01

    This study investigated the role of Accumulibacter-related bacterial populations and factors influencing their distribution in enhanced biological phosphorus removal (EBPR) systems in the USA. For this purpose, five full-scale wastewater treatment facilities performing EBPR were surveyed. The facilities had different configurations but were all treating primarily domestic wastewater. Two facilities had history of poor EBPR performance. Batch-scale acetate uptake and inorganic phosphate (P(i)) release and uptake experiments were conducted to evaluate the EBPR activity of each sludge. Typical P(i) and acetate profiles were observed, and EBPR activity was found to be positively correlated to polyphosphate (polyP)-accumulating organism (PAO) abundance, as determined by staining intracellular polyP. The abundance of Accumulibacter-related organisms was investigated using fluorescent in situ hybridization. Accumulibacter-related organisms were present in all full-scale EBPR facilities, at levels ranging from 9 to 24% of total cells. More than 80% of Accumulibacter-related organisms were estimated to have high polyP content, confirming their involvement in EBPR in these five facilities. However, Accumulibacter-related PAOs were only a fraction (40-69%) of the total PAO population. The variation of Accumulibacter-related PAO abundance among these EBPR systems suggests that multiple interacting factors such as wastewater characteristics and operational conditions are structuring PAO communities.

  18. Cross-flow turbines: progress report on physical and numerical model studies at large laboratory scale

    Science.gov (United States)

    Wosnik, Martin; Bachant, Peter

    2016-11-01

    Cross-flow turbines show potential in marine hydrokinetic (MHK) applications. A research focus is on accurately predicting device performance and wake evolution to improve turbine array layouts for maximizing overall power output, i.e., minimizing wake interference, or taking advantage of constructive wake interaction. Experiments were carried with large laboratory-scale cross-flow turbines D O (1 m) using a turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. Several turbines of varying solidity were employed, including the UNH Reference Vertical Axis Turbine (RVAT) and a 1:6 scale model of the DOE-Sandia Reference Model 2 (RM2) turbine. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier-Stokes models. Results are presented for the simulation of performance and wake dynamics of cross-flow turbines and compared with experiments and body-fitted mesh, blade-resolving CFD. Supported by NSF-CBET Grant 1150797, Sandia National Laboratories.

  19. Progress of organic matter degradation and maturity of compost produced in a large-scale composting facility.

    Science.gov (United States)

    Nakasaki, Kiyohiko; Marui, Taketoshi

    2011-06-01

    To monitor the progress of organic matter degradation in a large-scale composting facility, the percentage of organic matter degradation was determined by measuring CO(2) evolution during recomposting of compost samples withdrawn from the facility. The percentage of organic matter degradation was calculated as the ratio of the amount of CO(2) evolved from compost raw material to that evolved from each sample during recomposting in the laboratory composting apparatus. It was assumed that the difference in the cumulative emission of CO(2) between the compost raw material and a sample corresponds to the amount of CO( 2) evolved from the sample in the composting facility. Using this method, the changes in organic matter degradation during composting in practical large-scale composting facilities were estimated and it was found that the percentage of organic matter degradation increased more vigorously in the earlier stages than in the later stages of composting. The percentage of organic matter degradation finally reached 78 and 55% for the compost produced from garbage-animal manure mixture and distillery waste (shochu residue), respectively. It was thus ascertained that organic matter degradation progressed well in both composting facilities. Furthermore, by performing a plant growth assay, it was observed that the compost products of both the facilities did not inhibit seed germination and thus were useful in promoting plant growth.

  20. Applications of Magnetic Suspension Technology to Large Scale Facilities: Progress, Problems and Promises

    Science.gov (United States)

    Britcher, Colin P.

    1997-01-01

    This paper will briefly review previous work in wind tunnel Magnetic Suspension and Balance Systems (MSBS) and will examine the handful of systems around the world currently known to be in operational condition or undergoing recommissioning. Technical developments emerging from research programs at NASA and elsewhere will be reviewed briefly, where there is potential impact on large-scale MSBSS. The likely aerodynamic applications for large MSBSs will be addressed, since these applications should properly drive system designs. A recently proposed application to ultra-high Reynolds number testing will then be addressed in some detail. Finally, some opinions on the technical feasibility and usefulness of a large MSBS will be given.

  1. Progress in Root Cause and Fault Propagation Analysis of Large-Scale Industrial Processes

    Directory of Open Access Journals (Sweden)

    Fan Yang

    2012-01-01

    Full Text Available In large-scale industrial processes, a fault can easily propagate between process units due to the interconnections of material and information flows. Thus the problem of fault detection and isolation for these processes is more concerned about the root cause and fault propagation before applying quantitative methods in local models. Process topology and causality, as the key features of the process description, need to be captured from process knowledge and process data. The modelling methods from these two aspects are overviewed in this paper. From process knowledge, structural equation modelling, various causal graphs, rule-based models, and ontological models are summarized. From process data, cross-correlation analysis, Granger causality and its extensions, frequency domain methods, information-theoretical methods, and Bayesian nets are introduced. Based on these models, inference methods are discussed to find root causes and fault propagation paths under abnormal situations. Some future work is proposed in the end.

  2. Progress in Large-Scale Production of Graphene. Part 2: Vapor Methods

    Science.gov (United States)

    Li, Yuan; Chopra, Nitin

    2015-01-01

    Graphene is critical for applications in electronics, optical devices, thermal management, energy, and biosystems, while at the same time cost-effective and large-scale production of graphene is a challenge. In this regard, vapor phase graphene synthesis is a bottom-up approach, which could be compatible with device industry fabrication methods. Here, we review the state-of-the-art techniques developed for the scalable production of graphene in bottom-up approaches. These mainly include the epitaxial growth and chemical vapor deposition methods. Product quality, structure, and yields for different graphene growth techniques are discussed and specific examples are described. The article also emphasizes promising methods for scalable graphene production but still needing a deeper research understanding.

  3. Progress in Large-Scale Production of Graphene. Part 1: Chemical Methods

    Science.gov (United States)

    Li, Yuan; Chopra, Nitin

    2015-01-01

    Graphene is a two-dimensional nanomaterial that has unique electrical, mechanical, thermal, and optical properties. For realizing the practical applications of graphene, one of the major challenges lies in cost-effective production of graphene-based nanomaterials at a large scale. Significant research efforts have been demonstrated in regard to scalable manufacturing of graphene and show strong potential for their commercialization and industrialization. Here, we review the state-of-the-art techniques developed for the scalable production of graphene. This review mainly discusses the top-down techniques including exfoliation of bulk graphite and chemical reduction of graphene oxide. Critical comparison for graphene quality, structure, and yields for different techniques is discussed and specific examples are described in detail.

  4. 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.

  5. Minnesota wood energy scale-up project: a progress report 5 years after establishment

    Energy Technology Data Exchange (ETDEWEB)

    Downing, M. [Oak Ridge National Laboratory, Oak Ridge (United States); Langseth, D.; Pierce, R. [Champion International, Alexandria (United States); Lundblad, T. [WesMin Resource Conservation and Development, Alexandria (United States); Stoffel, R. [Minnesota Dept. of Natural Resources-Forestry, Alexandria (United States)

    1999-07-01

    Nearly 2000 acres of hybrid poplar have been growing on Conservation Reserve Program (CRP) land near Alexandria, Minnesota. Many collaborators have cost-shared with landowners on this pre-commercial demonstration project. The economic cost of land preparation, planting, and field maintenance have been collected at the field scale since 1994 (Downing et al., 1995; Downing et al., 1996). There have been many articles written and much information disseminated in popular and international press (Kroll et al., 1995, Downing et al., 1996, and Langseth, et al., 1997). More than 50 field trips have been conducted across landowner fields, and an extensive collection of photographs currently exists. During the next five years of the rotation, several management decisions will be made. Landowners, along with the U.S. Forest Service silviculturists and others will recommend an optimal harvesting time. This decision will be based, in part, on yield and survival data that have been collected since the third year of growth. Landowners will decide to whom to sell their timber, and at what price. Finally, upon harvest, one complete rotation of hybrid poplar will have been produced on privately owned land. (author)

  6. Biosynthetic inorganic chemistry.

    Science.gov (United States)

    Lu, Yi

    2006-08-25

    Inorganic chemistry and biology can benefit greatly from each other. Although synthetic and physical inorganic chemistry have been greatly successful in clarifying the role of metal ions in biological systems, the time may now be right to utilize biological systems to advance coordination chemistry. One such example is the use of small, stable, easy-to-make, and well-characterized proteins as ligands to synthesize novel inorganic compounds. This biosynthetic inorganic chemistry is possible thanks to a number of developments in biology. This review summarizes the progress in the synthesis of close models of complex metalloproteins, followed by a description of recent advances in using the approach for making novel compounds that are unprecedented in either inorganic chemistry or biology. The focus is mainly on synthetic "tricks" learned from biology, as well as novel structures and insights obtained. The advantages and disadvantages of this biosynthetic approach are discussed.

  7. Atomic Scale Imaging of the Electronic Structure and Chemistry of Graphene and Its Precursors on Metal Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, George W. [Columbia Univ., New York, NY (United States)

    2015-02-16

    The objectives of this project were to reveal the mechanisms and reaction processes that solid carbon materials undergo when combining with gases such as oxygen, water vapor and hydrocarbons. This research was focused on fundamental chemical events taking place on single carbon sheets of graphene, a two-dimensional, polycyclic carbon material that possesses remarkable chemical and electronic properties. Ultimately, this work is related to the role of these materials in mediating the formation of polycyclic aromatic hydrocarbons (PAH’s), their reactions at interfaces, and the growth of soot particles. Our intent has been to contribute to a fundamental understanding of carbon chemistry and the mechanisms that control the formation of PAH’s, which eventually lead to the growth of undesirable particulates. We expect increased understanding of these basic chemical mechanisms to spur development of techniques for more efficient combustion of fossil fuels and to lead to a concomitant reduction in the production of undesirable solid carbon material.

  8. Progress on Scaling the Sheared-Flow Stabilized Z-Pinch: The Fusion Z-Pinch Experiment ``FuZE''

    Science.gov (United States)

    Nelson, B. A.; Shumlak, U.; Claveau, E. L.; Forbes, E. G.; Golingo, R. P.; Stepanov, A. D.; Weber, T. R.; Zhang, Y.; McLean, H. S.; Higginson, D. P.; Schmidt, A. E.; Tummel, K. K.

    2017-10-01

    The sheared-flow-stabilized (SFS) Z-pinch ZaP experiment was constructed based on calculations showing stabilization of the kink and sausage instabilities with sufficient flow shear. ZaP experimentally demonstrated production and sustainment of an SFS Z-pinch for a wide range of plasma parameters, with densities up to n = 5 ×1022 m-3 and a pinch radius of a=1 cm. The follow-on ZaP-HD (high density) experiment demonstrated scaling of the SFS Z-pinch to 2-3x smaller radii and 10x higher densities than ZaP, with up to 1 keV temperatures. Based on the successful results of ZaP and ZaP-HD, the Fusion Z-pinch Experiment (FuZE) project is experimentally and computationally studying scaling the plasma performance toward fusion conditions, with the target of a smaller radius, a=1 mm, and higher density, n = 2 ×1024 m-3. Initial FuZE experimental results show several hundred eV ion temperatures, with pinch currents of 100-200 kA and a few mm radius. 2D kinetic calculations show stabilization of instabilities at moderate sheared flows, and 3D kinetic calculations are in progress. This work is supported by an award from US ARPA-E.

  9. Atomic-Scale Structure and Local Chemistry of CoFeB-MgO Magnetic Tunnel Junctions.

    Science.gov (United States)

    Wang, Zhongchang; Saito, Mitsuhiro; McKenna, Keith P; Fukami, Shunsuke; Sato, Hideo; Ikeda, Shoji; Ohno, Hideo; Ikuhara, Yuichi

    2016-03-09

    Magnetic tunnel junctions (MTJs) constitute a promising building block for future nonvolatile memories and logic circuits. Despite their pivotal role, spatially resolving and chemically identifying each individual stacking layer remains challenging due to spatially localized features that complicate characterizations limiting understanding of the physics of MTJs. Here, we combine advanced electron microscopy, spectroscopy, and first-principles calculations to obtain a direct structural and chemical imaging of the atomically confined layers in a CoFeB-MgO MTJ, and clarify atom diffusion and interface structures in the MTJ following annealing. The combined techniques demonstrate that B diffuses out of CoFeB electrodes into Ta interstitial sites rather than MgO after annealing, and CoFe bonds atomically to MgO grains with an epitaxial orientation relationship by forming Fe(Co)-O bonds, yet without incorporation of CoFe in MgO. These findings afford a comprehensive perspective on structure and chemistry of MTJs, helping to develop high-performance spintronic devices by atomistic design.

  10. Progress of ITER full tungsten divertor technology qualification in Japan: Manufacturing full-scale plasma-facing unit prototypes

    Energy Technology Data Exchange (ETDEWEB)

    Ezato, Koichiro, E-mail: ezato.koichiro@jaea.go.jp [Department of ITER Project, Naka Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency (Japan); Suzuki, Satoshi; Seki, Yohji; Yamada, Hirokazu; Hirayama, Tomoyuki; Yokoyama, Kenji [Department of ITER Project, Naka Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency (Japan); Escourbiac, Frederic; Hirai, Takeshi [ITER Organization, route de vinon sur Verdon, 13067 St Paul lez Durance (France)

    2016-11-01

    Highlights: • JADA has demonstrated the feasibility of manufacturing the full-W plasma-facing units (W-PFU). • The surface profiles of the W monoblocks of the W-PFU prototypes on the test frame to mimic the support structure of the ITER OVT were examined by using an optical three-dimensional measurement system. The results show the most W monoblock surface in the target part locates within + 0.25 mm from the CAD data. • The strict profile control with the profile tolerance of ±0.3 mm is imposed on the OVT to prevent the leading edges of the W monoblocks from over-heating. • The present full-scale prototyping demonstrates to satisfy this requirement on the surface profile. • It can be concluded that the technical maturities of JADA and its suppliers are as high as to start series manufacturing the ITER divertor components. - Abstract: Japan Atomic Energy Agency (JAEA) is in progress for technology demonstration toward Full-tungsten (W) ITER divertor outer vertical target (OVT), especially, W monoblock technology that needs to withstand the repetitive heat load as high as 20 MW/m{sup 2} for 10 s. Under the framework of the W divertor qualification program developed ITER organization, JAEA as Japanese Domestic Agency (JADA) manufactured seven full-scale plasma-facing unit (PFU) prototypes with the Japanese industries. Four prototypes that have 146 W monoblock joint with casted copper (Cu) interlayer passed successfully the ultrasonic testing. In the other three prototypes that have the different W/Cu interlayer joint, joint defects were found. The dimension measurements reveal the requirements of the gap between W monoblocks and the surface profile of PFU are feasible.

  11. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly progress report, July - September 1996

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1996-10-01

    The advanced fine-coal cleaning techniques such as column flotation, recovers a low-ash ultra-fine size clean-coal product. However, economical dewatering of the clean coal product to less than 20 percent moisture using conventional technology is difficult. This research program objective is to evaluate a novel coal surface modification technique developed at the University of Kentucky Center for Applied Energy Research in conjunction with conventional and advanced dewatering technique at a pilot scale. The study which is in progress is being conducted at the Powell Mountain Coal Company`s Mayflower preparation plant located in St. Charles, VA. During this quarter laboratory dewatering studies were conducted using a 4-in diameter laboratory chemical centrifuge. The baseline data provided a filter cake with about 32% moisture. Addition of 0.3 kg/t of a cationic surfactant lowered the moisture to 29%. Addition of anionic and non-ionic surfactant was not effective in reducing the filter cake moisture content. In the pilot scale studies, a comparison was conducted between the high pressure and vacuum dewatering techniques. The base line data with high pressure and vacuum filtration provided filter cakes with 23.6% and 27.8% moisture, respectively. Addition of 20 g/t of cationic flocculent provided 21% filter cake moisture using the high pressure filter. A 15% moisture filter cake was obtained using 1.5 kg/t of non-ionic surfactant. Vacuum filter provided about 23% to 25% moisture product with additional reagents. The high pressure filter processed about 3 to 4 times more solids compared to vacuum filter.

  12. Progression towards optimization of viscosity of highly concentrated carbonaceous solid-water slurries by incorporating and modifying surface chemistry parameters with and without additives

    Science.gov (United States)

    Mukherjee, Amrita

    Carbonaceous solid-water slurries (CSWS) are concentrated suspensions of coal, petcoke bitumen, pitch etc. in water which are used as feedstock for gasifiers. The high solid loading (60-75 wt.%) in the slurry increases CSWS viscosity. For easier handling and pumping of these highly loaded mixtures, low viscosities are desirable. Depending on the nature of the carbonaceous solid, solids loading in the slurry and the particle size distribution, viscosity of a slurry can vary significantly. Ability to accurately predict the viscosity of a slurry will provide a better control over the design of slurry transport system and for viscosity optimization. The existing viscosity prediction models were originally developed for hard-sphere suspensions and therefore do not take into account surface chemistry. As a result, the viscosity predictions using these models for CSWS are not very accurate. Additives are commonly added to decrease viscosity of the CSWS by altering the surface chemistry. Since additives are specific to CSWS, selection of appropriate additives is crucial. The goal of this research was to aid in optimization of CSWS viscosity through improved prediction and selection of appropriate additive. To incorporate effect of surface chemistry in the models predicting suspension viscosity, the effect of the different interfacial interactions caused by different surface chemistries has to be accounted for. Slurries of five carbonaceous solids with varying O/C ratio (to represent different surface chemistry parameters) were used for the study. To determine the interparticle interactions of the carbonaceous solids in water, interfacial energies were calculated on the basis of surface chemistries, characterized by contact angles and zeta potential measurements. The carbonaceous solid particles in the slurries were assumed to be spherical. Polar interaction energy (hydrophobic/hydrophilic interaction energy), which was observed to be 5-6 orders of magnitude higher than the

  13. Natural spatial and temporal variations in groundwater chemistry in fractured, sedimentary rocks: scale and implications for solute transport

    Energy Technology Data Exchange (ETDEWEB)

    Hoven, Stephen J. van der [Department of Geography-Geology, Illinois State University, Campus Box 4400, Normal, IL 61761 (United States)]. E-mail: vanderhoven@ilstu.edu; Kip Solomon, D. [Department of Geology and Geophyics, University of Utah, 135 S. 1460 E., Room 719, Salt Lake City, UT 84112 (United States); Moline, Gerilynn R. [10 Victorian Heights, Thackeray Road, London SW8 3TD (United Kingdom)

    2005-05-15

    Natural tracers (major ions, {delta} {sup 18}O, and O{sub 2}) were monitored to evaluate groundwater flow and transport to a depth of 20 m below the surface in fractured sedimentary (primarily shale and limestone) rocks. Large temporal variations in these tracers were noted in the soil zone and the saprolite, and are driven primarily by individual storm events. During nonstorm periods, an upward flow brings water with high TDS, constant {delta} {sup 18}O, and low dissolved O{sub 2} to the water table. During storm events, low TDS, variable {delta} {sup 18}O, and high dissolved O{sub 2} water recharges through the unsaturated zone. These oscillating signals are rapidly transmitted along fracture pathways in the saprolite, with changes occurring on spatial scales of several meters and on a time scale of hours. The variations decreased markedly below the boundary between the saprolite and less weathered bedrock. Variations in the bedrock units occurred on time scales of days and spatial scales of at least 20 m. The oscillations of chemical conditions in the shallow groundwater are hypothesized to have significant implications for solute transport. Solutes and colloids that adsorb onto aquifer solids can be released into solution by decreases in ionic strength and pH. The decreases in ionic strength also cause thermodynamic undersaturation of the groundwater with respect to some mineral species and may result in mineral dissolution. Redox conditions are also changing and may result in mineral dissolution/precipitation. The net result of these chemical variations is episodic transport of a wide range of dissolved solutes or suspended particles, a phenomenon rarely considered in contaminant transport studies.

  14. Meso-Scale Progressive Damage Behavior Characterization of Triaxial Braided Composites under Quasi-Static Tensile Load

    Science.gov (United States)

    Ren, Yiru; Zhang, Songjun; Jiang, Hongyong; Xiang, Jinwu

    2017-08-01

    Based on continuum damage mechanics (CDM), a sophisticated 3D meso-scale finite element (FE) model is proposed to characterize the progressive damage behavior of 2D Triaxial Braided Composites (2DTBC) with 60° braiding angle under quasi-static tensile load. The modified Von Mises strength criterion and 3D Hashin failure criterion are used to predict the damage initiation of the pure matrix and fiber tows. A combining interface damage and friction constitutive model is applied to predict the interface damage behavior. Murakami-Ohno stiffness degradation scheme is employed to predict the damage evolution process of each constituent. Coupling with the ordinary and translational symmetry boundary conditions, the tensile elastic response including tensile strength and failure strain of 2DTBC are in good agreement with the available experiment data. The numerical results show that the main failure modes of the composites under axial tensile load are pure matrix cracking, fiber and matrix tension failure in bias fiber tows, matrix tension failure in axial fiber tows and interface debonding; the main failure modes of the composites subjected to transverse tensile load are free-edge effect, matrix tension failure in bias fiber tows and interface debonding.

  15. Chemistry Dashboard

    Science.gov (United States)

    The Chemistry Dashboard is part of a suite of dashboards developed by EPA to help evaluate the safety of chemicals. The Chemistry Dashboard provides access to a variety of information on over 700,000 chemicals currently in use.

  16. Linking local riverbed flow patterns and pore-water chemistry to hydrogeologic and geomorphic features across scales

    Science.gov (United States)

    Ibrahim, T. G.; Thornton, S.; Surridge, B.; Wainwright, J.

    2009-12-01

    The groundwater-surface water interface (GSI) is a critical environmental hotspot, a key area influencing the fate of carbon, nutrients and contaminants of surface and subsurface origin, and a zone of ecological importance. Policy seeking to mitigate issues relating to dissolved contaminants and to improve stream health, increasingly recognizes its significance, particularly in the context of integrated management of streams and aquifers. Techniques assessing riverbed flow and solute patterns are often limited to the local scale. When related to the multi-scale pattern of hydrogeologic and geomorphic features controlling stream, hyporheic and groundwater fluxes, they can improve larger scale predictions of flow and solute behaviour at the GSI. This study develops a conceptual model of riverbed flow and solute patterns, and tests it in a 4th order stream in the UK. It assesses the interaction between large scale subsurface flowpaths, driven by the distribution of bedrock outcrops, and the expansion and closure of alluvial deposits, and small-scale hyporheic flowpaths, driven by riffle-pool sequences. It uses two networks of riverbed mini-piezometers and multi-level samplers: network 1, across fifteen sites in a 7.2 km length of river in unconstrained (open alluvial valley), asymmetric (bedrock outcropping on one bank) and constrained (bedrock on both banks) contexts; and network 2, across six riffle-pool sequences in a 350-m reach, at the transition between asymmetric/unconstrained and constrained contexts. Subsurface flowpaths and stream-water infiltration were deduced by relating vertical exchange fluxes to stream and pore-water patterns of conservative natural tracers. Biogeochemical processes were highlighted using reactive natural tracers. At network 2, measurements of surface water profiles and riverbed coring were also undertaken, and dissolved metal concentrations in the first 15 cm of sediments assessed using gel probes. Network 1 was sampled twice. Monthly

  17. 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....

  18. Arrows in Chemistry

    Indian Academy of Sciences (India)

    IAS Admin

    reaction conditions, reagents and catalysts used in the chemical reaction are written on the chemical reaction arrow. For example,. Arrows in chemistry can be broadly classified as 'reaction arrows' and 'electron arrows'. While the former is used to describe the state or progress of a chemical reaction, the latter is used to.

  19. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-08-21

    written in Python that make calls to a precompiled quantum chemistry package (NWChem) are demonstrated to provide an actual speedup of 8.2 for a 2.5 ps AIMD simulation of HCl+4H2O at the MP2/6-31G* level. Implemented in this way these algorithms can be used for long time high-level AIMD simulations at a modest cost using machines connected by very slow networks such as WiFi, or in different time zones connected by the Internet. The algorithms can also be used with programs that are already parallel. By using these algorithms we are able to reduce the cost of a MP2/6-311++G(2d,2p) simulation that had reached its maximum possible speedup in the parallelization of the electronic structure calculation from 32 seconds per time step to 6.9 seconds per time step.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bylaska, Eric J., E-mail: Eric.Bylaska@pnnl.gov [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States); Weare, Jonathan Q., E-mail: weare@uchicago.edu [Department of Mathematics, University of Chicago, Chicago, Illinois 60637 (United States); Weare, John H., E-mail: jweare@ucsd.edu [Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States)

    2013-08-21

    to 14.3. The parallel in time algorithms can be implemented in a distributed computing environment using very slow transmission control protocol/Internet protocol networks. Scripts written in Python that make calls to a precompiled quantum chemistry package (NWChem) are demonstrated to provide an actual speedup of 8.2 for a 2.5 ps AIMD simulation of HCl + 4H{sub 2}O at the MP2/6-31G* level. Implemented in this way these algorithms can be used for long time high-level AIMD simulations at a modest cost using machines connected by very slow networks such as WiFi, or in different time zones connected by the Internet. The algorithms can also be used with programs that are already parallel. Using these algorithms, we are able to reduce the cost of a MP2/6-311++G(2d,2p) simulation that had reached its maximum possible speedup in the parallelization of the electronic structure calculation from 32 s/time step to 6.9 s/time step.

  2. Effectiveness of Scaling up the ‘Three Pillars’ Approach to Accelerating MDG 4 Progress in Ethiopia

    Science.gov (United States)

    Dougherty, Leanne; Pomeroy, Amanda M.; Karim, Ali M.; Mekonnen, Yared M.; Mulligan, Brian E.

    2014-01-01

    ABSTRACT This paper describes the integrated approach taken by the Government of Ethiopia with support from the Essential Services for Health in Ethiopia (ESHE) Project and assesses its effect on the coverage of six child health practices associated with reducing child mortality. The ESHE Project was designed to contribute to reducing high child mortality rates at scale among 14.5 million people through the ‘three pillars’ approach. This approach aimed to (i) strengthen health systems, (ii) improve health workers’ performance, and (iii) engage the community. The intervention was designed with national and subnational stakeholders’ input. To measure the Project's effect on the coverage of child health practices, we used a quasi-experimental design, with representative household survey data from the three most populous regions of Ethiopia, collected at the 2003-2004 baseline and 2008 endline surveys of the Project. A difference-in-differences analysis model detected an absolute effect of the ESHE intervention of 8.4% points for DTP3 coverage (p=0.007), 12.9% points for measles vaccination coverage (p<0.001), 12.6% points for latrines (p=0.002), and 9.8% points for vitamin A supplementation (p<0.001) across the ESHE-intervention districts (woredas) compared to all non-ESHE districts of the same three regions. Improvements in the use of modern family planning methods and exclusive breastfeeding were not significant. Important regional variations are discussed. ESHE was one of several partners of the Ministry of Health whose combined efforts led to accelerated progress in the coverage of child health practices. PMID:25895187

  3. Scale-dependent effects of land cover on water physico-chemistry and diatom-based metrics in a major river system, the Adour-Garonne basin (South Western France)

    Energy Technology Data Exchange (ETDEWEB)

    Tudesque, Loïc, E-mail: loic.tudesque@univ-tlse3.fr [CNRS, Université Paul Sabatier, ENFA, UMR5174 EDB (Laboratoire Évolution and Diversité Biologique), 118 route de Narbonne, F-31062 Toulouse (France); Université Toulouse 3 Paul Sabatier, CNRS, UMR5174 EDB, F-31062 Toulouse (France); Tisseuil, Clément [CNRS, Université Paul Sabatier, ENFA, UMR5174 EDB (Laboratoire Évolution and Diversité Biologique), 118 route de Narbonne, F-31062 Toulouse (France); Université Toulouse 3 Paul Sabatier, CNRS, UMR5174 EDB, F-31062 Toulouse (France); Lek, Sovan, E-mail: sovan.lek@univ-tlse3.fr [CNRS, Université Paul Sabatier, ENFA, UMR5174 EDB (Laboratoire Évolution and Diversité Biologique), 118 route de Narbonne, F-31062 Toulouse (France); Université Toulouse 3 Paul Sabatier, CNRS, UMR5174 EDB, F-31062 Toulouse (France)

    2014-01-01

    The scale dependence of ecological phenomena remains a central issue in ecology. Particularly in aquatic ecology, the consideration of the accurate spatial scale in assessing the effects of landscape factors on stream condition is critical. In this context, our study aimed at assessing the relationships between multi-spatial scale land cover patterns and a variety of water quality and diatom metrics measured at the stream reach level. This investigation was conducted in a major European river system, the Adour-Garonne river basin, characterized by a wide range of ecological conditions. Redundancy analysis (RDA) and variance partitioning techniques were used to disentangle the different relationships between land cover, water-chemistry and diatom metrics. Our results revealed a top-down “cascade effect” indirectly linking diatom metrics to land cover patterns through water physico-chemistry, which occurred at the largest spatial scales. In general, the strength of the relationships between land cover, physico-chemistry, and diatoms was shown to increase with the spatial scale, from the local to the basin scale, emphasizing the importance of continuous processes of accumulation throughout the river gradient. Unexpectedly, we established that the influence of land cover on the diatom metric was of primary importance both at the basin and local scale, as a result of discontinuous but not necessarily antagonist processes. The most detailed spatial grain of the Corine land cover classification appeared as the most relevant spatial grain to relate land cover to water chemistry and diatoms. Our findings provide suitable information to improve the implementation of effective diatom-based monitoring programs, especially within the scope of the European Water Framework Directive. - Highlights: •The spatial scale dependence of the “cascade effect” in a river system has been demonstrated. •The strength of the relationships between land cover and diatoms through

  4. Atomic-Scale Design of Iron Fischer-Tropsch Catalysts: A Combined Computational Chemistry, Experimental, and Microkinetic Modeling Approach

    Energy Technology Data Exchange (ETDEWEB)

    Manos Mavrikakis; James A. Dumesic; Rahul P. Nabar

    2006-09-29

    Work continued on the development of a microkinetic model of Fischer-Tropsch synthesis (FTS) on supported and unsupported Fe catalysts. The following aspects of the FT mechanism on unsupported iron catalysts were investigated on during this third year: (1) the collection of rate data in a Berty CSTR reactor based on sequential design of experiments; (2) CO adsorption and CO-TPD for obtaining the heat of adsorption of CO on polycrystalline iron; and (3) isothermal hydrogenation (IH) after Fischer Tropsch reaction to identify and quantify surface carbonaceous species. Rates of C{sub 2+} formation on unsupported iron catalysts at 220 C and 20 atm correlated well to a Langmuir-Hinshelwood type expression, derived assuming carbon hydrogenation to CH and OH recombination to water to be rate-determining steps. From desorption of molecularly adsorbed CO at different temperatures the heat of adsorption of CO on polycrystalline iron was determined to be 100 kJ/mol. Amounts and types of carbonaceous species formed after FT reaction for 5-10 minutes at 150, 175, 200 and 285 C vary significantly with temperature. Mr. Brian Critchfield completed his M.S. thesis work on a statistically designed study of the kinetics of FTS on 20% Fe/alumina. Preparation of a paper describing this work is in progress. Results of these studies were reported at the Annual Meeting of the Western States Catalysis and at the San Francisco AIChE meeting. In the coming period, studies will focus on quantitative determination of the rates of kinetically-relevant elementary steps on unsupported Fe catalysts with/without K and Pt promoters by SSITKA method. This study will help us to (1) understand effects of promoter and support on elementary kinetic parameters and (2) build a microkinetics model for FTS on iron. Calculations using periodic, self-consistent Density Functional Theory (DFT) methods were performed on models of defected Fe surfaces, most significantly the stepped Fe(211) surface. Binding

  5. Research in nuclear chemistry. Progress report, March 1, 1976--February 28, 1977. [Actinide and lanthanide complexes with organic and inorganic ligands

    Energy Technology Data Exchange (ETDEWEB)

    Choppin, Gregory R.

    1976-01-01

    The study of the binding of actinide ions by the humic and fulvic acid fractions of humus soil has been initiated. Comparison of the thermodynamics of binding of actinides by these soil fractions with the analogous data for a variety of monomer ligands of the type expected to be present in humic acid may enable us to derive a useful model for actinide sorption by humus soils. Inasmuch as humus constitutes a large fraction of the soils of the world, development of a model for its binding of actinide ions could be most helpful in understanding the environmental chemistry of the actinide elements. Our investigation of the binding of the actinide ions by these soil fractions has been coupled with a study of the protonation thermodynamics of humic acid in order to provide a more full characterization of these materials.

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

    OpenAIRE

    Marek Tobiszewski; Mariusz Marć; Agnieszka Gałuszka; Jacek Namieśnik

    2015-01-01

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

  7. Chemistry Technology

    Data.gov (United States)

    Federal Laboratory Consortium — Chemistry technology experts at NCATS engage in a variety of innovative translational research activities, including:Design of bioactive small molecules.Development...

  8. Mathematics for physical chemistry

    CERN Document Server

    Mortimer, Robert G

    2005-01-01

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

  9. The Relationships between University Students' Chemistry Laboratory Anxiety, Attitudes, and Self-Efficacy Beliefs

    Science.gov (United States)

    Kurbanoglu, N. Izzet; Akin, Ahmet

    2010-01-01

    The aim of this study is to examine the relationships between chemistry laboratory anxiety, chemistry attitudes, and self-efficacy. Participants were 395 university students. Participants completed the Chemistry Laboratory Anxiety Scale, the Chemistry Attitudes Scale, and the Self-efficacy Scale. Results showed that chemistry laboratory anxiety…

  10. THE PROGRESS STUDY OF TRADITIONAL TURKISH MUSIC LESSONS SELF-EFFICACY PERCEPTION SCALE FOR MUSIC TEACHING PROGRAMME

    Directory of Open Access Journals (Sweden)

    Koray Celenk

    2017-01-01

    Full Text Available The aim of this research is to develop a scale in order to determine the perspective of self-efficacy related to the course Traditional Turkish Music (Traditional Turkish Folk Music/Traditional Turkish Classical Music, which takes place in the curriculum of Faculty of Education, Department of Fine Arts Education, Division of Music Education. The working group of this research consists of 97 students who receive training in the division of Music Education in Atatürk, Niğde (Ömer Halisdemir, Uludağ and Pamukkale Universities. The research is a descriptive study. In the research, general scanning method has been used, self efficacy- scale both in and non-area have been examined, literature review has been done and a scale, as research result, has been developed in order to determine possible Music teachers’ perspective of self-efficacy related to the course Traditional Turkish Music. An item pool has been formed for the validity of the scale, having prepared an expert opinion form the items have been submitted for consideration, getting the content validity ratios (CVR of the items and the content validity index of the whole scale, taking the margin of error of 5 percent, statistical significance has been tested. To determine the construct validity of the scale the factor analysis has been made and it has been confirmed that the scale has a single factor structure and establishes construct validity. Pilot scheme has been done to check the validity of the scale. Within this scope, the reliability coefficient of the scale has been calculated as 0.842 cronbach’s alpha and the scale developed is highly reliable. As a result, the scale developed is a valid and reliable tool to determine possible Music teachers’ perspective of self-efficacy related to the course Traditional Turkish Music.

  11. Prognostic Ability of Practitioners of Traditional Arabic Medicine: Comparison with Western Methods through a Relative Patient Progress Scale

    Directory of Open Access Journals (Sweden)

    Bertrand Graz

    2010-01-01

    Full Text Available The ancient Greek medical theory based on balance or imbalance of humors disappeared in the western world, but does survive elsewhere. Is this survival related to a certain degree of health care efficiency? We explored this hypothesis through a study of classical Greco-Arab medicine in Mauritania. Modern general practitioners evaluated the safety and effectiveness of classical Arabic medicine in a Mauritanian traditional clinic, with a prognosis/follow-up method allowing the following comparisons: (i actual patient progress (clinical outcome compared with what the traditional ‘tabib’ had anticipated (= prognostic ability and (ii patient progress compared with what could be hoped for if the patient were treated by a modern physician in the same neighborhood. The practice appeared fairly safe and, on average, clinical outcome was similar to what could be expected with modern medicine. In some cases, patient progress was better than expected. The ability to correctly predict an individual's clinical outcome did not seem to be better along modern or Greco-Arab theories. Weekly joint meetings (modern and traditional practitioners were spontaneously organized with a modern health centre in the neighborhood. Practitioners of a different medical system can predict patient progress. For the patient, avoiding false expectations with health care and ensuring appropriate referral may be the most important. Prognosis and outcome studies such as the one presented here may help to develop institutions where patients find support in making their choices, not only among several treatment options, but also among several medical systems.

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

    Directory of Open Access Journals (Sweden)

    Marek Tobiszewski

    2015-06-01

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

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

    Science.gov (United States)

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

    2015-06-12

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

  14. 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,

  15. Chemistry of Transactinides

    Science.gov (United States)

    Kratz, J. V.

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

  16. Significant steps in the evolution of analytical chemistry--is the today's analytical chemistry only chemistry?

    Science.gov (United States)

    Karayannis, Miltiades I; Efstathiou, Constantinos E

    2012-12-15

    In this review the history of chemistry and specifically the history and the significant steps of the evolution of analytical chemistry are presented. In chronological time spans, covering the ancient world, the middle ages, the period of the 19th century, and the three evolutional periods, from the verge of the 19th century to contemporary times, it is given information for the progress of chemistry and analytical chemistry. During this period, analytical chemistry moved gradually from its pure empirical nature to more rational scientific activities, transforming itself to an autonomous branch of chemistry and a separate discipline. It is also shown that analytical chemistry moved gradually from the status of exclusive serving the chemical science, towards serving, the environment, health, law, almost all areas of science and technology, and the overall society. Some recommendations are also directed to analytical chemistry educators concerning the indispensable nature of knowledge of classical analytical chemistry and the associated laboratory exercises and to analysts, in general, why it is important to use the chemical knowledge to make measurements on problems of everyday life. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. 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...

  18. Nuclear Chemistry.

    Science.gov (United States)

    Chemical and Engineering News, 1979

    1979-01-01

    Provides a brief review of the latest developments in nuclear chemistry. Nuclear research today is directed toward increased activity in radiopharmaceuticals and formation of new isotopes by high-energy, heavy-ion collisions. (Author/BB)

  19. 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.

  20. Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres. Progress report, May 1, 1993--January 31, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hopke, P.K.

    1993-01-01

    Progress is reported on the chemical and physical behavior of the {sup 218}Po atom immediately following its formation by the alpha decay of radon. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical processes that affect the progeny`s atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. The specific tasks addressed were to determine the formation rates of {center_dot}OH radicals formed by the radiolysis of air following radon decay, to examine the formation of particles by the radiolytic oxidation of substances like SO{sub 2}, ethylene, and H{sub 2}S to lower vapor pressure compounds and determine the role of gas phase additives such as H{sub 2}O and NH{sub 3} in determining the particle size, to measure the rate of ion-induced nucleation using a thermal diffusion cloud chamber, and to measure the neutralization rate of {sup 218}PoO{sub x}{sup +} in O{sub 2} at low radon concentrations. Initial measurements were conducted of the activity size distributions in actual homes with occupants present so that the variability of the indoor activity size distributions can be assessed with respect to indoor aerosol sources and general lifestyle variations of the occupants. A prospective study of the utility of measurement of deposited {sup 210}Pb embedded in glass surfaces as a measure of the long-term, integrated exposure of the population to radon are described. Methodology was developed to determine the hygroscopicity of the indoor aerosol so that the changes in deposition efficiency of the radioactive indoor aerosol with hygroscopic growth in the respiratory tract can be assessed.

  1. The slow birth of green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Amato, I.

    1993-03-12

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

  2. Ultrafast phenomena in molecular sciences femtosecond physics and chemistry

    CERN Document Server

    Bañares, Luis

    2014-01-01

    This book presents the latest developments in Femtosecond Chemistry and Physics for the study of ultrafast photo-induced molecular processes. Molecular systems, from the simplest H2 molecule to polymers or biological macromolecules, constitute central objects of interest for Physics, Chemistry and Biology, and despite the broad range of phenomena that they exhibit, they share some common behaviors. One of the most significant of those is that many of the processes involving chemical transformation (nuclear reorganization, bond breaking, bond making) take place in an extraordinarily short time, in or around the femtosecond temporal scale (1 fs = 10-15 s). A number of experimental approaches - very particularly the developments in the generation and manipulation of ultrashort laser pulses - coupled with theoretical progress, provide the ultrafast scientist with powerful tools to understand matter and its interaction with light, at this spatial and temporal scale. This book is an attempt to reunite some of the ...

  3. Progress in computational toxicology.

    Science.gov (United States)

    Ekins, Sean

    2014-01-01

    Computational methods have been widely applied to toxicology across pharmaceutical, consumer product and environmental fields over the past decade. Progress in computational toxicology is now reviewed. A literature review was performed on computational models for hepatotoxicity (e.g. for drug-induced liver injury (DILI)), cardiotoxicity, renal toxicity and genotoxicity. In addition various publications have been highlighted that use machine learning methods. Several computational toxicology model datasets from past publications were used to compare Bayesian and Support Vector Machine (SVM) learning methods. The increasing amounts of data for defined toxicology endpoints have enabled machine learning models that have been increasingly used for predictions. It is shown that across many different models Bayesian and SVM perform similarly based on cross validation data. Considerable progress has been made in computational toxicology in a decade in both model development and availability of larger scale or 'big data' models. The future efforts in toxicology data generation will likely provide us with hundreds of thousands of compounds that are readily accessible for machine learning models. These models will cover relevant chemistry space for pharmaceutical, consumer product and environmental applications. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Measuring Armenia's progress on the Tobacco Control Scale: an evaluation of tobacco control in an economy in transition, 2005-2009.

    Science.gov (United States)

    Movsisyan, Narine K; Connolly, Gregory N

    2014-02-27

    This study aimed to measure the 5-year progress in the implementation of WHO Framework Convention on Tobacco Control (FCTC) in Armenia by applying the Tobacco Control Scale, a rapid assessment tool developed to assess the strength of tobacco control policies in Europe. Armenia, an economy in transition, has extreme smoking rates among men (62.5%) despite acceding to FCTC in 2004. However, little research has been carried out to evaluate Armenia's progress in tobacco control. The Tobacco Control Scale total score was estimated for Armenia using the original methodology; however, a different source of data was used in estimating the subscores on tobacco price and tobacco control spending. Armenia's total score on Tobacco Control Scale has considerably improved from 2005 to 2009, mostly due to larger health warnings and advertising ban, and increased public spending on tobacco control. The scores for smoke-free public places, advertising ban, health warnings and treatment categories were below the European average in 2005 and 2007, while the price score was higher. Neither total tobacco control score nor any of its components showed a significant predictive value in a simple regression analysis using the total score and subscores as predictors for log-transformed per capita tobacco consumption. Higher than the European average price score for Armenia cannot be explained by the concept of affordability alone and may reflect a measurement error due to peculiarities of transition economies. The applicability of the Tobacco Control Scale could be limited to countries with mature economies, but not to transition countries such as Armenia with different social, political and economic environment. The scale modification, such as an adjustment for the policy enforcement and the effectiveness of public tobacco control spending along with alternative measures of affordability would be warranted to enhance its applicability in low-income and middle-income countries.

  5. Walking speed, rather than Expanded Disability Status Scale, relates to long-term patient-reported impact in progressive MS

    NARCIS (Netherlands)

    Bosma, L.V.A.E.; Kragt, J.J.; Polman, C.H.; Uitdehaag, B.M.J.

    2013-01-01

    Objective: To study the relationships between 1-2 year changes in well-known physician-rated measurements (Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT)) and the long-term (= 5 years) outcome in patient-reported outcome (PRO) measures (Multiple Sclerosis

  6. The Impact of the Progressive Efficiency Test on a Rowing Ergometer on White Blood Cells Distribution and Clinical Chemistry Changes in Paralympic Rowers During the Preparatory Stage Before the Paralympic Games in Rio, 2016 – A Case Report

    Science.gov (United States)

    Nowak, Robert; Buryta, Rafał; Krupecki, Krzysztof; Zając, Tomasz; Zawartka, Marek; Proia, Patrizia

    2017-01-01

    Abstract There is a large gap in knowledge regarding research on post-exercise blood changes in disabled athletes. There are relatively few data on adaptive mechanisms to exercise in disabled athletes, including disabled rowers. Two rowers from a Polish adaptive rowing settle TAMix2x that qualified for the Paralympic Games in Rio, 2016 took part in this study. They performed a progressive test on a rowing ergometer until exhaustion. The cardiorespiratory fitness measures, complete blood count, white blood cells’ distribution and 30 clinical chemistry variables describing laboratory diagnostic profiles and general health were determined. The extreme effort induced changes in all studied metabolites (glucose, creatinine, urea, uric acid, total and direct bilirubin), albumin, total protein levels in both participants. Furthermore, a post-exercise increase in aspartate transaminase activity, yet a 2-fold decrease during the recovery time in both rowers were found. White blood cell count increased 2-fold after the test. The percentages of natural killer cells were higher and total T lymphocytes were lower after the exercise protocol. There were higher percentages of suppressor/cytotoxic and lower percentages of helper/inducer T lymphocyte subsets in both studied rowers. No changes in B lymphocytes distribution were observed. Lack of inflammatory symptoms during the experiment suggests a high level of rowers’ biological adaptation to the physical effort. The different changes in physiological, biochemical and immunological variables are related to the adaptive mechanism to physical exercise allowing for improvement of performance. PMID:29340006

  7. The Impact of the Progressive Efficiency Test on a Rowing Ergometer on White Blood Cells Distribution and Clinical Chemistry Changes in Paralympic Rowers During the Preparatory Stage Before the Paralympic Games in Rio, 2016 - A Case Report.

    Science.gov (United States)

    Nowak, Robert; Buryta, Rafał; Krupecki, Krzysztof; Zając, Tomasz; Zawartka, Marek; Proia, Patrizia; Kostrzewa-Nowak, Dorota

    2017-12-01

    There is a large gap in knowledge regarding research on post-exercise blood changes in disabled athletes. There are relatively few data on adaptive mechanisms to exercise in disabled athletes, including disabled rowers. Two rowers from a Polish adaptive rowing settle TAMix2x that qualified for the Paralympic Games in Rio, 2016 took part in this study. They performed a progressive test on a rowing ergometer until exhaustion. The cardiorespiratory fitness measures, complete blood count, white blood cells' distribution and 30 clinical chemistry variables describing laboratory diagnostic profiles and general health were determined. The extreme effort induced changes in all studied metabolites (glucose, creatinine, urea, uric acid, total and direct bilirubin), albumin, total protein levels in both participants. Furthermore, a post-exercise increase in aspartate transaminase activity, yet a 2-fold decrease during the recovery time in both rowers were found. White blood cell count increased 2-fold after the test. The percentages of natural killer cells were higher and total T lymphocytes were lower after the exercise protocol. There were higher percentages of suppressor/cytotoxic and lower percentages of helper/inducer T lymphocyte subsets in both studied rowers. No changes in B lymphocytes distribution were observed. Lack of inflammatory symptoms during the experiment suggests a high level of rowers' biological adaptation to the physical effort. The different changes in physiological, biochemical and immunological variables are related to the adaptive mechanism to physical exercise allowing for improvement of performance.

  8. The Impact of the Progressive Efficiency Test on a Rowing Ergometer on White Blood Cells Distribution and Clinical Chemistry Changes in Paralympic Rowers During the Preparatory Stage Before the Paralympic Games in Rio, 2016 – A Case Report

    Directory of Open Access Journals (Sweden)

    Nowak Robert

    2017-12-01

    Full Text Available There is a large gap in knowledge regarding research on post-exercise blood changes in disabled athletes. There are relatively few data on adaptive mechanisms to exercise in disabled athletes, including disabled rowers. Two rowers from a Polish adaptive rowing settle TAMix2x that qualified for the Paralympic Games in Rio, 2016 took part in this study. They performed a progressive test on a rowing ergometer until exhaustion. The cardiorespiratory fitness measures, complete blood count, white blood cells’ distribution and 30 clinical chemistry variables describing laboratory diagnostic profiles and general health were determined. The extreme effort induced changes in all studied metabolites (glucose, creatinine, urea, uric acid, total and direct bilirubin, albumin, total protein levels in both participants. Furthermore, a post-exercise increase in aspartate transaminase activity, yet a 2-fold decrease during the recovery time in both rowers were found. White blood cell count increased 2-fold after the test. The percentages of natural killer cells were higher and total T lymphocytes were lower after the exercise protocol. There were higher percentages of suppressor/cytotoxic and lower percentages of helper/inducer T lymphocyte subsets in both studied rowers. No changes in B lymphocytes distribution were observed. Lack of inflammatory symptoms during the experiment suggests a high level of rowers’ biological adaptation to the physical effort. The different changes in physiological, biochemical and immunological variables are related to the adaptive mechanism to physical exercise allowing for improvement of performance.

  9. 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.

  10. Parallel supercomputing: Advanced methods, algorithms and software for large-scale problems. Progress report, April 1991--April 1992

    Energy Technology Data Exchange (ETDEWEB)

    Carey, G.F.; Young, D.M.

    1992-04-01

    Research has continued with excellent progress and new results on methodology and algorithms. We have also made supporting benchmark application studies on representative parallel computing architectures. Results from these research studies have been reported at scientific meetings, as technical reports and as journal publications. A list of pertinent presentations and publications is attached. The work on parallel element-by-element techniques and domain decomposition schemes has developed well. In particular, we have focused on the use of finite element spectral methods (or high p methods) on distributed massively parallel systems. The approach has been implemented in a prototype finite element program for solution of coupled Navier Stokes flow and transport processes. This class of problems is of fundamental interest and basic to many ``grand challenge`` type problems for which parallel supercomputing is warranted.

  11. Progress of Large-Scale Synthesis and Electronic Device Application of Two-Dimensional Transition Metal Dichalcogenides.

    Science.gov (United States)

    Song, Xiongfei; Guo, Zhongxun; Zhang, Qiaochu; Zhou, Peng; Bao, Wenzhong; Zhang, David Wei

    2017-09-01

    The recent exploration of semiconducting two-dimensional (2D) transition metal dichalcogenides (TMDs) with atomic thickness has taken both the scientific and technological communities by storm. Extensively investigated TMD that are accessible by large-scale synthetic methods materials are remarkably stable, such as MoS2 and WSe2 . They allow superior gate control due to their 2D nature and favorable electronic transport properties, thus suggesting a bright future for digital and RF electronics. In this review, the latest developments in the controlled synthesis of large scale TMDs are firstly introduced by discussing various approaches. The major obstacles that must be overcome to achieve wafer-scale, uniform, and high-quality TMD films for practical electronic applications are included. Advances in the electronic transport studies of TMDs are presented, such as doping, contact engineering, and mobility improvement, which contribute to overall device performance. A perspective and a look at the future for this field is provided in closing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. 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.

  13. Final Progress Report: FRACTURE AND SUBCRITICAL DEBONDING IN THIN LAYERED STRUCTURES: EXPERIMENTS AND MULTI-SCALE MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Reinhold H. Dauskardt

    2005-08-30

    Final technical report detailing unique experimental and multi-scale computational modeling capabilities developed to study fracture and subcritical cracking in thin-film structures. Our program to date at Stanford has studied the mechanisms of fracture and fatigue crack-growth in structural ceramics at high temperature, bulk and thin-film glasses in selected moist environments where we demonstrated the presence of a true mechanical fatigue effect in some glass compositions. We also reported on the effects of complex environments and fatigue loading on subcritical cracking that effects the reliability of MEMS and other micro-devices using novel micro-machined silicon specimens and nanomaterial layers.

  14. Food carbohydrate chemistry

    National Research Council Canada - National Science Library

    Wrolstad, R. E

    2012-01-01

    .... Now in Food Carbohydrate Chemistry, author Wrolstad emphasizes the application of carbohydrate chemistry to understanding the chemistry, physical and functional properties of food carbohydrates...

  15. POC-scale testing of an advanced equipment/technology. Quarterly technical progress report No. 1, October--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, J.G.; Parekh, B.K.

    1995-01-30

    The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the University of Kentucky Center for Applied Energy Research (UKCAER) will be evaluated using vacuum, centrifuge, and hyperbaric filtration systems. Dewatering tests will be conducted using the fine clean coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high sulfur and low sulfur clean coal. The Mayflower Plant processes coals from five different seams, thus the dewatering studies results could be generalized for most of the bituminous coals. The project team met with the DOE project management representatives at the Pittsburgh Energy Technology Center on November 18, 1994 to review project plans. After review and comments provided by the DOE, the Project Management and Work Plans were issued on December 15, 1994. The project team held a meeting at the Powell Mountain Coal Company Mayflower Preparation Plant to discuss the strategy on installation and operation of the various dewatering units. Samples of the low sulfur and high sulfur clean coal froths were collected and shipped to UKCAER and Andritz Ruthner Inc.

  16. Analytical Chemistry in Russia.

    Science.gov (United States)

    Zolotov, Yuri

    2016-09-06

    Research in Russian analytical chemistry (AC) is carried out on a significant scale, and the analytical service solves practical tasks of geological survey, environmental protection, medicine, industry, agriculture, etc. The education system trains highly skilled professionals in AC. The development and especially manufacturing of analytical instruments should be improved; in spite of this, there are several good domestic instruments and other satisfy some requirements. Russian AC has rather good historical roots.

  17. Confectionary Chemistry.

    Science.gov (United States)

    Levine, Elise Hilf

    1996-01-01

    Presents activities and demonstrations that enable teachers to use various types of confections as tactile experiences to spark chemistry students' interest and generate enthusiasm for learning. Presents uses of candy in teaching about atomic structure, spontaneous nuclear decay, chemical formulas, fractoluminescence, the effect of a molecular…

  18. Chemistry Notes.

    Science.gov (United States)

    School Science Review, 1983

    1983-01-01

    Presents chemistry experiments, laboratory procedures, demonstrations, and classroom materials/activities. These include: experiments on colloids, processing of uranium ore, action of heat on carbonates; color test for phenols and aromatic amines; solvent properties of non-electrolytes; stereoscopic applications/methods; a valency balance;…

  19. Optimization and scale-up of fermentation process for production of microbial polysaccharide. Final technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Buller, C.S.

    1994-12-21

    This grant was awarded to provide for the scale-up of the process of production of a (1 {r_arrow})-{beta}-D-glucan which is produced by Cellulomonas flavigena. One of the goals was to provide sufficient amounts of the polysaccharide polymer to conduct a field test of its usefulness in subterranean permeability modification procedures of enhanced oil recovery. During September and October, 1994, fermentations and recoveries were done by Abbott Laboratories, to develop a process to provide at least 400 lbs of the glucan polymer for field testing. Shake flask runs and four fermentation runs were completed. A summary of the fourth fermentation run, conducted in a 40,000 liter fermentor, follows.

  20. Quantum-chemistry based calibration of the alkali metal cation series (Li(+)-Cs(+)) for large-scale polarizable molecular mechanics/dynamics simulations.

    Science.gov (United States)

    Dudev, Todor; Devereux, Mike; Meuwly, Markus; Lim, Carmay; Piquemal, Jean-Philip; Gresh, Nohad

    2015-02-15

    The alkali metal cations in the series Li(+)-Cs(+) act as major partners in a diversity of biological processes and in bioinorganic chemistry. In this article, we present the results of their calibration in the context of the SIBFA polarizable molecular mechanics/dynamics procedure. It relies on quantum-chemistry (QC) energy-decomposition analyses of their monoligated complexes with representative O-, N-, S-, and Se- ligands, performed with the aug-cc-pVTZ(-f) basis set at the Hartree-Fock level. Close agreement with QC is obtained for each individual contribution, even though the calibration involves only a limited set of cation-specific parameters. This agreement is preserved in tests on polyligated complexes with four and six O- ligands, water and formamide, indicating the transferability of the procedure. Preliminary extensions to density functional theory calculations are reported. © 2014 Wiley Periodicals, Inc.

  1. IV. Health physics and chemistry

    Energy Technology Data Exchange (ETDEWEB)

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

    1948-05-24

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

  2. Catalysis and sustainable (green) chemistry

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-01-15

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

  3. Facilitating Phenological Assessments at Local, Regional and National Scales: Year Two Progress of the USA National Phenology Network

    Science.gov (United States)

    Weltzin, J. F.

    2009-12-01

    Patterns of phenology for plants and animals control ecosystem processes, determine land surface properties, control biosphere-atmosphere interactions, and affect food production, health, conservation, and recreation. Although directional climate change has already caused documented shifts in organismal, population, community and ecosystem-level patterns and processes, a national phenological assessment requires a comprehensive suite of standardized methodologies to track phenology across a range of spatial and temporal scales (e.g., organismal to landscapes). The USA National Phenology Network (USA-NPN; www.usanpn.org) is an emerging and exciting partnership between federal agencies, the academic community, and the general public to establish a national science and monitoring initiative focused on phenology as a tool to understand how plants, animals and landscapes respond to climate variation, and as a tool to facilitate human adaptation to ongoing and potential future climate change. USA-NPN will (1) integrate with other formal and informal science observation networks (e.g., NEON, LTER, Ameriflux, NPS I & M, OBFS, GEO, public gardens, conservation groups) including regional phenology networks; (2) utilize and enhance remote sensing products, emerging technologies and data management capabilities; and (3) capitalize on myriad educational opportunities and a new readiness of the public to participate in investigations of nature on a national scale. In its second year of operation, USA-NPN produced many new phenology products and venues for phenology research and citizen involvement that will facilitate local, regional or national assessments of phenology. A new web-page contains an advanced on-line user interface to facilitate entry of contemporary data into the National Phenology Database. The new plant phenology monitoring program provides standardized methodologies and monitoring protocols for 215 local, regional, and nationally distributed plant species

  4. A software environment for large-scale sequencing. Comprehensive progress report: February 23, 1991--July 15, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, C.B.

    1993-07-08

    The authors are developing a next-generation software environment to support large-scale DNA sequencing for the Human Genome Project. The goal is to automate the data flow from its generation by the DNA sequencing hardware to the final reconstructed sequence. Thus, the emphasis is on automation while providing efficient graphical interfaces for interaction with or inspection of the data. A secondary goal is to develop a system flexible enough to support a range of sequencing strategies, including random, and various directed and mixed strategies. The project will result in a software product named the {open_quotes}Genome Reconstruction Manager{close_quotes} (GRM). The authors are presently engaged in the final phase during which they plan to deliver a production quality system to a small number of DNA sequencing laboratories. By the end of the project they will have accomplished the main objectives stated in their original proposal except that GRM will not include all of the analytical capabilities that were planned. The reason for this is that the system proved to be much more complex than originally expected and required more effort to be devoted to system design and implementation. However, the design of GRM anticipates the addition of analytical capabilities and the strategy to fucus on system design has resulted in a solid foundation on which to build.

  5. Small scale laboratory studies of flow and transport phenonmena in pores and fractures, Phase II. Second yearly progress report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.L.

    1993-04-01

    Small scale laboratory experiments, equipped with an ability to actually observe behavior on the pore level using microscopy, provide an economical and easily understood scientific tool to help us validateconcepts and assumptions about the transport of contaminants, and offers the propensity to discover heretofore unrecognized phenomena or behavior. The main technique employs etched glass micromodels, composed of two etched glass plates, sintered together, to form a two dimensional network of three dimensional pores. Flow and transport behavior is observed on a pore or pore network level, and recorded on film and video tape. This technique is coupled with related column studies. Specifically we`re examining multiphase flow behavior of relevance, for example, to liquid-liquid mass transfer (solubilization of capillary trapped organic liquids); liquid-gas mass transfer (in situ volatilization); colloid movement, attachment and detachment in the presence of fluid-fluid interfaces; bacteria colonization and motility in porous systems; and heterogeneity effects on multi-phase flow, colloid movement and bacteria behavior.

  6. Large-scale identification of clinical and genetic predictors of motor progression in patients with newly diagnosed Parkinson's disease: a longitudinal cohort study and validation.

    Science.gov (United States)

    Latourelle, Jeanne C; Beste, Michael T; Hadzi, Tiffany C; Miller, Robert E; Oppenheim, Jacob N; Valko, Matthew P; Wuest, Diane M; Church, Bruce W; Khalil, Iya G; Hayete, Boris; Venuto, Charles S

    2017-11-01

    Better understanding and prediction of progression of Parkinson's disease could improve disease management and clinical trial design. We aimed to use longitudinal clinical, molecular, and genetic data to develop predictive models, compare potential biomarkers, and identify novel predictors for motor progression in Parkinson's disease. We also sought to assess the use of these models in the design of treatment trials in Parkinson's disease. A Bayesian multivariate predictive inference platform was applied to data from the Parkinson's Progression Markers Initiative (PPMI) study (NCT01141023). We used genetic data and baseline molecular and clinical variables from patients with Parkinson's disease and healthy controls to construct an ensemble of models to predict the annual rate of change in combined scores from the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) parts II and III. We tested our overall explanatory power, as assessed by the coefficient of determination (R 2 ), and replicated novel findings in an independent clinical cohort from the Longitudinal and Biomarker Study in Parkinson's disease (LABS-PD; NCT00605163). The potential utility of these models for clinical trial design was quantified by comparing simulated randomised placebo-controlled trials within the out-of-sample LABS-PD cohort. 117 healthy controls and 312 patients with Parkinson's disease from the PPMI study were available for analysis, and 317 patients with Parkinson's disease from LABS-PD were available for validation. Our model ensemble showed strong performance within the PPMI cohort (five-fold cross-validated R 2 41%, 95% CI 35-47) and significant-albeit reduced-performance in the LABS-PD cohort (R 2 9%, 95% CI 4-16). Individual predictive features identified from PPMI data were confirmed in the LABS-PD cohort. These included significant replication of higher baseline MDS-UPDRS motor score, male sex, and increased age, as well as a novel Parkinson's disease

  7. Advances in Phosphasilene Chemistry.

    Science.gov (United States)

    Nesterov, Vitaly; Breit, Nora C; Inoue, Shigeyoshi

    2017-09-07

    Heavier alkene analogues possess unique electronic properties and reactivity, encouraging multidisciplinary research groups to utilize them in the rational design of novel classes of compounds and materials. Phosphasilenes are heavier imine analogues, containing highly reactive Si=P double bonds. Recent achievements in this field are closely related to the progress in the chemistry of stable low-coordinate silicon compounds. In this Review, we have attempted to summarize in a comprehensive way the available data on the structures, syntheses, electronic and chemical properties of these compounds, with an emphasis on recent achievements. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Progress in national-scale landslide susceptibility mapping in Romania using a combined statistical-heuristical approach

    Science.gov (United States)

    Bălteanu, Dan; Micu, Mihai; Malet, Jean-Philippe; Jurchescu, Marta; Sima, Mihaela; Kucsicsa, Gheorghe; Dumitrică, Cristina; Petrea, Dănuţ; Mărgărint, Ciprian; Bilaşco, Ştefan; Văcăreanu, Radu; Georgescu, Sever; Senzaconi, Francisc

    2017-04-01

    Landslide processes represent a very widespread geohazard in Romania, affecting mainly the hilly and plateau regions as well as the mountain sectors developed on flysch formations. Two main projects provided the framework for improving the existing national landslide susceptibility map (Bălteanu et al. 2010): the ELSUS (Pan-European and nation-wide landslide susceptibility assessment, EC-CERG) and the RO-RISK (Disaster Risk Evaluation at National Level, ESF-POCA) projects. The latter one, a flagship project aiming at strengthening risk prevention and management in Romania, focused on a national-level evaluation of the main risks in the country including landslides. The strategy for modeling landslide susceptibility was designed based on the experience gained from continental and national level assessments conducted in the frame of the International Programme on Landslides (IPL) project IPL-162, the European Landslides Expert Group - JRC and the ELSUS project. The newly proposed landslide susceptibility model used as input a reduced set of landslide conditioning factor maps available at scales of 1:100,000 - 1:200,000 and consisting of lithology, slope angle and land cover. The input data was further differentiated for specific natural environments, defined here as morpho-structural units in order to incorporate differences induced by elevation (vertical climatic zonation), morpho-structure as well as neotectonic features. In order to best discern the specific landslide conditioning elements, the analysis has been carried out for one single process category, namely slides. The existence of a landslide inventory covering the whole country's territory ( 30,000 records, Micu et al. 2014), although affected by incompleteness and lack of homogeneity, allowed for the application of a semi-quantitative, mixed statistical-heuristical approach having the advantage of combining the objectivity of statistics with expert-knowledge in calibrating class and factor weights. The

  9. Changes in Lens Opacities on the Age-Related Eye Disease Study Grading Scale Predict Progression to Cataract Surgery and Vision Loss

    Science.gov (United States)

    Indaram, Maanasa; Agrón, Elvira; Clemons, Traci E.; Sperduto, Robert D.; Wong, Wai T.; Ferris, Frederick L.; Chew, Emily Y.

    2015-01-01

    Purpose To investigate whether the two year change in severity of lens opacities on the Age-Related Eye Disease Study (AREDS) lens grading scale predicts progression to cataract surgery or loss of visual acuity by 5 years. Design Prospective, cohort study within a randomized clinical trial of oral supplements Participants AREDS participants whose eyes were phakic at baseline and free of late AMD throughout the study. Methods Baseline and annual lens photographs of AREDS participants (n=3466/4757; 73%) were graded for severity of cataract using the AREDS System for Classifying Cataracts from Photographs. Clinical exams conducted semi-annually collected data on cataract surgery and visual acuity. Association of the change in lens opacities at 2 years with these outcomes at 5 years was analyzed with adjusted Cox proportional hazard models. Main Outcome Measurements Progression of lens opacities on stereoscopic lens photographs at 2 years, cataract surgery, and visual acuity loss of 2 or more lines at 5 years. Results The adjusted hazard ratios (HR) for association of progression to cataract surgery at 5 years, were: nuclear cataract increase of 1.0 unit or greater compared with cataract increase of 5% or greater in lens opacity in the central 5mm of the lens, compared with cataract increase of 5% or greater vs. <5% in the central 5 mm of the lens: 8.25 (95% CL: 5.55–12.29, p<.001). Similarly, HRs of vision loss of ≥2 lines at 5 years for this degree of lens changes at 2 years were the following: nuclear: 1.83 (95% CL: 1.49–2.25, p<.001); cortical: 1.13 (95% CL: 0.78–1.65, p=.519); and PSC: 3.05 (95% CL: 1.79–5.19, p<0.001). Conclusions Two-year changes in severity of lens opacities on the AREDS lens grading scale are predictive of long-term clinically relevant outcomes, making them potential surrogate endpoints in follow-up studies. PMID:25682177

  10. Relationships between water, otolith, and scale chemistries of westslope cutthroat trout from the Coeur d'Alene River, Idaho: the potential application of hard-part chemistry to describe movements in freshwater

    Science.gov (United States)

    Brian K. Wells; Bruce E. Rieman; James L. Clayton; Donna L. Horan; Cynthia M. Jones

    2003-01-01

    We quantified Mg:Ca, Mn:Ca, Sr:Ca, and Ba:Ca molar ratios from an area representing the summer 2000 growth season on otoliths and scales from 1-year-old westslope cutthroat trout Oncorhyncus clarki lewisi collected from three streams in the Coeur d'Alene River, Idaho, system. We also quantified Mg:Ca, Sr:Ca, and Ba:Ca molar ratios in the water...

  11. 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

  12. A refuge for inorganic chemistry: Bunsen's Heidelberg laboratory.

    Science.gov (United States)

    Nawa, Christine

    2014-05-01

    Immediately after its opening in 1855, Bunsen's Heidelberg laboratory became iconic as the most modern and best equipped laboratory in Europe. Although comparatively modest in size, the laboratory's progressive equipment made it a role model for new construction projects in Germany and beyond. In retrospect, it represents an intermediate stage of development between early teaching facilities, such as Liebig's laboratory in Giessen, and the new 'chemistry palaces' that came into existence with Wöhler's Göttingen laboratory of 1860. As a 'transition laboratory,' Bunsen's Heidelberg edifice is of particular historical interest. This paper explores the allocation of spaces to specific procedures and audiences within the laboratory, and the hierarchies and professional rites of passage embedded within it. On this basis, it argues that the laboratory in Heidelberg was tailored to Bunsen's needs in inorganic and physical chemistry and never aimed at a broad-scale representation of chemistry as a whole. On the contrary, it is an example of early specialisation within a chemical laboratory preceding the process of differentiation into chemical sub-disciplines. Finally, it is shown that the relatively small size of this laboratory, and the fact that after ca. 1860 no significant changes were made within the building, are inseparably connected to Bunsen's views on chemistry teaching.

  13. Interstellar chemistry

    Science.gov (United States)

    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 observed is a challenge for complete understanding. The role and nature of reactions involving grain surfaces as well as new spectroscopic observations of interstellar and circumstellar regions are topics presented in this special feature. PMID:16894148

  14. Development of the Connected Chemistry as Formative Assessment Pedagogy for High School Chemistry Teaching

    Science.gov (United States)

    Park, Mihwa; Liu, Xiufeng; Waight, Noemi

    2017-01-01

    This paper describes the development of Connected Chemistry as Formative Assessment (CCFA) pedagogy, which integrates three promising teaching and learning approaches, computer models, formative assessments, and learning progressions, to promote student understanding in chemistry. CCFA supports student learning in making connections among the…

  15. A comparison of two chemistry and aerosol schemes on the regional scale and the resulting impact on radiative properties and liquid- and ice-phase aerosol-cloud interactions

    Science.gov (United States)

    Glassmeier, Franziska; Possner, Anna; Vogel, Bernhard; Vogel, Heike; Lohmann, Ulrike

    2017-07-01

    The complexity of atmospheric aerosol causes large uncertainties in its parameterization in atmospheric models. In a process-based comparison of two aerosol and chemistry schemes within the regional atmospheric modeling framework COSMO-ART (Consortium for Small-Scale Modelling, Aersosol and Reactive Trace gases extension), we identify key sensitivities of aerosol parameterizations. We consider the aerosol module MADE (Modal Aerosol Dynamics model for Europe) in combination with full gas-phase chemistry and the aerosol module M7 in combination with a constant-oxidant-field-based sulfur cycle. For a Saharan dust outbreak reaching Europe, modeled aerosol populations are more sensitive to structural differences between the schemes, in particular the consideration of aqueous-phase sulfate production, the selection of aerosol species and modes, and modal composition, than to parametric choices like modal standard deviation and the parameterization of aerosol dynamics. The same observation applies to aerosol optical depth (AOD) and the concentrations of cloud condensation nuclei (CCN). Differences in the concentrations of ice-nucleating particles (INPs) are masked by uncertainties between two ice-nucleation parameterizations and their coupling to the aerosol scheme. Differences in cloud droplet and ice crystal number concentrations are buffered by cloud microphysics as we show in a susceptibility analysis.

  16. 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).

  17. Immobilization chemistries.

    Science.gov (United States)

    Todt, Sascha; Blohm, Dietmar H

    2009-01-01

    Among the parameters which influence the success of a microarray experiment, the attachment of the nucleic acid captures to the support surface plays a decisive role.This article attempts to review the main concepts and ideas of the multiple variants which exist in terms of the immobilization chemistries used in nucleic acid microarray technology. Starting from the attachment of unmodified nucleic acids to modified glass slides by adsorption, further strategies for the coupling of nucleic acid capture molecules to a variety of support materials are surveyed with a focus on the reactive groups involved in the respective process.After a brief introduction, an overview is given about microarray substrates with special emphasis on the approaches used for the activation of these - usually chemically inert - materials. In the next sections strategies for the "undefined" and "defined" immobilization of captures on the substrates are described. While the latter approach tries to accomplish the coupling via a defined reactive moiety of the molecule to be immobilized, the former mentioned techniques involve multiply occurring reactive groups in the capture.The article finishes with an example for microarray manufacture, the production of aminopropyltriethoxysilane (APTES) functionalized glass substrates to which PDITC homobifunctional linker molecules are coupled; on their part providing reactive functional groups for the covalent immobilization of pre-synthesized, amino-modified oligonucleotides.This survey does not seek to be comprehensive rather it tries to present and provide key examples for the basic techniques, and to enable orientation if more detailed studies are needed. This review should not be considered as a guide to how to use the different chemistries described, but instead as a presentation of various principles and approaches applied in the still evolving field of nucleic acid microarray technology.

  18. Decadal to multi-decadal scale variability of Indian summer monsoon rainfall in the coupled ocean-atmosphere-chemistry climate model SOCOL-MPIOM

    Science.gov (United States)

    Malik, Abdul; Brönnimann, Stefan; Stickler, Alexander; Raible, Christoph C.; Muthers, Stefan; Anet, Julien; Rozanov, Eugene; Schmutz, Werner

    2017-01-01

    The present study is an effort to deepen the understanding of Indian summer monsoon rainfall (ISMR) on decadal to multi-decadal timescales. We use ensemble simulations for the period AD 1600-2000 carried out by the coupled Atmosphere-Ocean-Chemistry-Climate Model (AOCCM) SOCOL-MPIOM. Firstly, the SOCOL-MPIOM is evaluated using observational and reanalyses datasets. The model is able to realistically simulate the ISMR as well as relevant patterns of sea surface temperature and atmospheric circulation. Further, the influence of Atlantic Multi-decadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), and El Niño Southern Oscillation (ENSO) variability on ISMR is realistically simulated. Secondly, we investigate the impact of internal climate variability and external climate forcings on ISMR on decadal to multi-decadal timescales over the past 400 years. The results show that AMO, PDO, and Total Solar Irradiance (TSI) play a considerable role in controlling the wet and dry decades of ISMR. Resembling observational findings most of the dry decades of ISMR occur during a negative phase of AMO and a simultaneous positive phase of PDO. The observational and simulated datasets reveal that on decadal to multi-decadal timescales the ISMR has consistent negative correlation with PDO whereas its correlation with AMO and TSI is not stationary over time.

  19. Dragonfly Mercury Project—A citizen science driven approach to linking surface-water chemistry and landscape characteristics to biosentinels on a national scale

    Science.gov (United States)

    Eagles-Smith, Collin A.; Nelson, Sarah J.; Willacker,, James J.; Flanagan Pritz, Colleen M.; Krabbenhoft, David P.

    2016-02-29

    Mercury is a globally distributed pollutant that threatens human and ecosystem health. Even protected areas, such as national parks, are subjected to mercury contamination because it is delivered through atmospheric deposition, often after long-range transport. In aquatic ecosystems, certain environmental conditions can promote microbial processes that convert inorganic mercury to an organic form (methylmercury). Methylmercury biomagnifies through food webs and is a potent neurotoxicant and endocrine disruptor. The U.S. Geological Survey (USGS), the University of Maine, and the National Park Service (NPS) Air Resources Division are working in partnership at more than 50 national parks across the United States, and with citizen scientists as key participants in data collection, to develop dragonfly nymphs as biosentinels for mercury in aquatic food webs. To validate the use of these biosentinels, and gain a better understanding of the connection between biotic and abiotic pools of mercury, this project also includes collection of landscape data and surface-water chemistry including mercury, methylmercury, pH, sulfate, and dissolved organic carbon and sediment mercury concentration. Because of the wide geographic scope of the research, the project also provides a nationwide “snapshot” of mercury in primarily undeveloped watersheds.

  20. Decadal to multi-decadal scale variability of Indian summer monsoon rainfall in the coupled ocean-atmosphere-chemistry climate model SOCOL-MPIOM

    Science.gov (United States)

    Malik, Abdul; Brönnimann, Stefan; Stickler, Alexander; Raible, Christoph C.; Muthers, Stefan; Anet, Julien; Rozanov, Eugene; Schmutz, Werner

    2017-11-01

    The present study is an effort to deepen the understanding of Indian summer monsoon rainfall (ISMR) on decadal to multi-decadal timescales. We use ensemble simulations for the period AD 1600-2000 carried out by the coupled Atmosphere-Ocean-Chemistry-Climate Model (AOCCM) SOCOL-MPIOM. Firstly, the SOCOL-MPIOM is evaluated using observational and reanalyses datasets. The model is able to realistically simulate the ISMR as well as relevant patterns of sea surface temperature and atmospheric circulation. Further, the influence of Atlantic Multi-decadal Oscillation (AMO), Pacific Decadal Oscillation (PDO), and El Niño Southern Oscillation (ENSO) variability on ISMR is realistically simulated. Secondly, we investigate the impact of internal climate variability and external climate forcings on ISMR on decadal to multi-decadal timescales over the past 400 years. The results show that AMO, PDO, and Total Solar Irradiance (TSI) play a considerable role in controlling the wet and dry decades of ISMR. Resembling observational findings most of the dry decades of ISMR occur during a negative phase of AMO and a simultaneous positive phase of PDO. The observational and simulated datasets reveal that on decadal to multi-decadal timescales the ISMR has consistent negative correlation with PDO whereas its correlation with AMO and TSI is not stationary over time.

  1. 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 ...

  2. USSR Report Chemistry

    National Research Council Canada - National Science Library

    1986-01-01

    Contents: Adsorption, Chemistry,Alkaloids, Analytical Chemistry, Catalysis,Chemical Industry,,Coal Gasification, Combustion, Electrochemistry,Explosives and Explosions, Fertilizers, Free Radicals, Inorganic...

  3. 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)

  4. Mars aqueous chemistry experiment

    Science.gov (United States)

    Clark, Benton C.; Mason, Larry W.

    1993-01-01

    The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

  5. 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.

  6. Recent progress in microcalorimetry

    CERN Document Server

    Calvet, E; Skinner, H A

    2013-01-01

    Recent Progress in Microcalorimetry focuses on the methodologies, processes, and approaches involved in microcalorimetry, as well as heat flow, temperature constancy, and chemistry of alumina and cements.The selection first offers information on the different types of calorimeters; measurement of the heat flow between the calorimeter and jacket boundaries by means of a thermoelectric pile; and constructional details of the microcalorimeter. Discussions focus on classification of calorimeters, use of thermoelectric piles as thermometers, correct measurement of heat flow from a calorimeter conta

  7. Microscale Experiments in Chemistry - The Need of the New Millenium

    Indian Academy of Sciences (India)

    carbohydrate chemistry. He had been associated with popularizing microscale chemistry from its inception in. India. In each of the four parts 1 of this series, we stressed the need for implementing microscale techniques in chemistry laboratories and described various experiments for employme:nt on smaller scale.

  8. Zambian Pre-Service Chemistry Teachers' Views on Chemistry Education Goals and Challenges for Achieving Them in Schools

    Science.gov (United States)

    Banda, Asiana; Mumba, Frackson; Chabalengula, Vivien M.

    2014-01-01

    This study examined Zambian preservice chemistry teachers' views on the goals of chemistry education, the importance of the goals, and challenges for achieving them in schools. The study sample was comprised of 59 pre-service chemistry teachers at the University of Zambia. Data were collected using a modified Likert-scale questionnaire that was…

  9. PROBLEMS AND SOLUTIONS IN CHEMISTRY EDUCATION

    OpenAIRE

    TSAPARLIS, Georgios

    2016-01-01

    As an established research field, chemistry education, is relatively a young one – its origins go back only to the 1970s. The present author has started his engagement with chemistry education since the late 1970s, and as a consequence he has followed the progress of the field over the years. This paper will focus on the challenges (the “problems”) confronting a teacher of chemistry, and on suggestions for solutions as these follow from the findings of educational research, with emphasis on t...

  10. Chemistry in Our Life

    Indian Academy of Sciences (India)

    IAS Admin

    toothpaste, soaps and cosmetics, (7) plastics and polymers, (8) chemistry in health and disease, (9) chemistry of building, (10) fire chemistry and (11) chemistry of electricity. To write on these topics at a popular level for lay persons, without bringing in chemical for- mulas, structures or equations, is extremely difficult.

  11. Atmospheric Chemistry and Air Pollution

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Gaffney

    2003-01-01

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

  12. Mars aqueous chemistry experiment

    Science.gov (United States)

    Clark, Benton C.; Mason, Larry W.

    1994-01-01

    Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

  13. 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...

  14. In-situ exploration of Venus on a global scale : direct measurements of origins and evolution, meterology, dynamics, and chemistry by a long-duration aerial science station

    Science.gov (United States)

    Baines, Kevin H.; Atreya, Sushi; Carlson, Robert W.; Chutjian, Ara; Crisp, David; Hall, Jeffrey L.; Jones, Dayton L.; Kerzhanovich, Victor V.; Limaye, Sanjay S.

    2005-01-01

    Drifting in the strong winds of Venus under benign Earth-like temperature and pressure conditions, an instrumented balloon-borne science station presents a viable means to explore, in-situ, the Venusian atmosphere on a global scale. Flying over the ground at speeds exceeding 240 km/hour while floating in the Venusian skies near 55 km altitude for several weeks, such an aerostat can conduct a 'world tour' of our neighboring planet, as it circumnavigates the globe multiple times during its flight from equatorial to polar latitudes. Onboard science sensors can repeatedly and directly sample gas compositions, atmospheric pressures and temperatures and cloud particle properties, giving unprecedented insight into the chemical processes occurring within the sulfuric clouds. Additionally, interferometric tracking via Earth-based radio observatories can yield positions and windspeeds to better than 10 cm/sec over one-hour periods, providing important information for understanding the planet's meridional circulation and enigmatic zonal super-rotation, as well as local dynamics associated with meteorological processes. As well, hundreds of GCMS spectra collected during the flight can provide measurements of noble gas compositions and their isotopes with unprecedented accuracy, thereby enabling fundamental new insights into Venus's origin and evolution.

  15. Context-specific, evidence-based planning for scale-up of family planning services to increase progress to MDG 5: health systems research.

    Science.gov (United States)

    Byrne, Abbey; Morgan, Alison; Soto, Eliana Jimenez; Dettrick, Zoe

    2012-11-12

    Unmet need for family planning is responsible for 7.4 million disability-adjusted life years and 30% of the maternity-related disease burden. An estimated 35% of births are unintended and some 200 million couples state a desire to delay pregnancy or cease fertility but are not using contraception. Unmet need is higher among the poorest, lesser educated, rural residents and women under 19 years. The barriers to, and successful strategies for, satisfying all demand for modern contraceptives are heavily influenced by context. Successfully overcoming this to increase the uptake of family planning is estimated to reduce the risk of maternal death by up to 58% as well as contribute to poverty reduction, women's empowerment and educational, social and economic participation, national development and environmental protection. To strengthen health systems for delivery of context-specific, equity-focused reproductive, maternal, newborn and child health services (RMNCH), the Investment Case study was applied in the Asia-Pacific region. Staff of local and central government and non-government organisations analysed data indicative of health service delivery through a supply-demand oriented framework to identify constraints to RMNCH scale-up. Planners developed contextualised strategies and the projected coverage increases were modelled for estimates of marginal impact on maternal mortality and costs over a five year period. In Indonesia, Philippines and Nepal the constraints behind incomplete coverage of family planning services included: weaknesses in commodities logistic management; geographical inaccessibility; limitations in health worker skills and numbers; legislation; and religious and cultural ideologies. Planned activities included: streamlining supply systems; establishment of Community Health Teams for integrated RMNCH services; local recruitment of staff and refresher training; task-shifting; and follow-up cards. Modelling showed varying marginal impact and costs

  16. Context-specific, evidence-based planning for scale-up of family planning services to increase progress to MDG 5: health systems research

    Directory of Open Access Journals (Sweden)

    Byrne Abbey

    2012-11-01

    Full Text Available Abstract Background Unmet need for family planning is responsible for 7.4 million disability-adjusted life years and 30% of the maternity-related disease burden. An estimated 35% of births are unintended and some 200 million couples state a desire to delay pregnancy or cease fertility but are not using contraception. Unmet need is higher among the poorest, lesser educated, rural residents and women under 19 years. The barriers to, and successful strategies for, satisfying all demand for modern contraceptives are heavily influenced by context. Successfully overcoming this to increase the uptake of family planning is estimated to reduce the risk of maternal death by up to 58% as well as contribute to poverty reduction, women’s empowerment and educational, social and economic participation, national development and environmental protection. Methods To strengthen health systems for delivery of context-specific, equity-focused reproductive, maternal, newborn and child health services (RMNCH, the Investment Case study was applied in the Asia-Pacific region. Staff of local and central government and non-government organisations analysed data indicative of health service delivery through a supply–demand oriented framework to identify constraints to RMNCH scale-up. Planners developed contextualised strategies and the projected coverage increases were modelled for estimates of marginal impact on maternal mortality and costs over a five year period. Results In Indonesia, Philippines and Nepal the constraints behind incomplete coverage of family planning services included: weaknesses in commodities logistic management; geographical inaccessibility; limitations in health worker skills and numbers; legislation; and religious and cultural ideologies. Planned activities included: streamlining supply systems; establishment of Community Health Teams for integrated RMNCH services; local recruitment of staff and refresher training; task-shifting; and follow

  17. Effects of regional-scale and convective transports on tropospheric ozone chemistry revealed by aircraft observations during the wet season of the AMMA campaign

    Science.gov (United States)

    Ancellet, G.; Leclair de Bellevue, J.; Mari, C.; Nedelec, P.; Kukui, A.; Borbon, A.; Perros, P.

    2009-01-01

    The African Monsoon Multidisciplinary Analyses (AMMA) fourth airborne campaign was conducted in July-August 2006 to study the chemical composition of the middle and upper troposphere in West Africa with the major objective to better understand the processing of chemical emissions by the West African Monsoon (WAM) and its associated regional-scale and vertical transports. In particular, the french airborne experiment was organized around two goals. The first was to characterize the impact of Mesoscale Convective Systems (MCSs) on the ozone budget in the upper troposphere and the evolution of the chemical composition of these convective plumes as they move westward toward the Atlantic Ocean. The second objective was to discriminate the impact of remote sources of pollution over West Africa, including transport from the middle east, Europe, Asia and from southern hemispheric fires. Observations of O3, CO, NOx, H2O and hydroperoxide above West Africa along repeated meridional transects were coupled with transport analysis based on the FLEXPART lagrangian model. The cross analysis of trace gas concentrations and transport pathways revealed 5 types of air masses: convective uplift of industrial and urban emissions, convective uplift of biogenic emissions, slow advection from Cotonou polluted plumes near the coast, meridional transport of upper tropospheric air from the subtropical barrier region, and meridional transport of Southern Hemisphere (SH) biomass burning emissions. O3/CO correlation plots and the correlation plots of H2O2 with a OH proxy revealed not only a control of the trace gas variability by transport processes but also significant photochemical reactivity in the mid- and upper troposphere. The study of four MCSs outflow showed contrasted chemical composition and air mass origins depending on the MCSs lifetime and latitudinal position. Favorables conditions for ozone production were found for MCSs with increased MCS lifetime (>1.5 days), which allowed for

  18. Effects of regional-scale and convective transports on tropospheric ozone chemistry revealed by aircraft observations during the wet season of the AMMA campaign

    Directory of Open Access Journals (Sweden)

    G. Ancellet

    2009-01-01

    Full Text Available The African Monsoon Multidisciplinary Analyses (AMMA fourth airborne campaign was conducted in July–August 2006 to study the chemical composition of the middle and upper troposphere in West Africa with the major objective to better understand the processing of chemical emissions by the West African Monsoon (WAM and its associated regional-scale and vertical transports. In particular, the french airborne experiment was organized around two goals. The first was to characterize the impact of Mesoscale Convective Systems (MCSs on the ozone budget in the upper troposphere and the evolution of the chemical composition of these convective plumes as they move westward toward the Atlantic Ocean. The second objective was to discriminate the impact of remote sources of pollution over West Africa, including transport from the middle east, Europe, Asia and from southern hemispheric fires. Observations of O3, CO, NOx, H2O and hydroperoxide above West Africa along repeated meridional transects were coupled with transport analysis based on the FLEXPART lagrangian model. The cross analysis of trace gas concentrations and transport pathways revealed 5 types of air masses: convective uplift of industrial and urban emissions, convective uplift of biogenic emissions, slow advection from Cotonou polluted plumes near the coast, meridional transport of upper tropospheric air from the subtropical barrier region, and meridional transport of Southern Hemisphere (SH biomass burning emissions. O3/CO correlation plots and the correlation plots of H2O2 with a OH proxy revealed not only a control of the trace gas variability by transport processes but also significant photochemical reactivity in the mid- and upper troposphere. The study of four MCSs outflow showed contrasted chemical composition and air mass origins depending on the MCSs lifetime and latitudinal position. Favorables conditions for ozone

  19. 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.

  20. [Research Advances in Postmortem Chemistry].

    Science.gov (United States)

    Han, Shun-qi; Qin, Zhi-qiang; Deng, Kai-fei; Zhang, Jian-hua; Liu, Ning-guo; Zou, Dong-hua; Li, Zheng-dong; Shao, Yu; Huang, Ping; Chen, Yi-jiu

    2015-08-01

    Postmortem chemistry is becoming more and more essential in routine forensic pathology and has made considerable progress over the past years. Biochemical analyses of vitreous humor, blood, urine and cerebrospinal fluid may provide important information in determining the cause of death or in elucidating forensic issues. Postmortem chemistry may be essential for the determination of cause of death when morphological methods (diabetes mellitus, alcoholic ketoacidosis and electrolytic disorders) cannot detect the pathophysiological changes involved in the death process. It can also provide many information in other forensic situations, including myocardial ischemia, sepsis, inflammation, infection, anaphylaxis and hormonal disturbances. The most recent relevant research advances on glucose metabolism, liver function, cardiac function, renal function, sepsis, inflammation, infection, anaphylaxis and hormonal aspect are hereby reviewed.

  1. Coordination Chemistry of Life Processes: Bioinorganic Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Coordination Chemistry of Life Processes: Bioinorganic Chemistry. R N Mukherjee. General Article Volume 4 Issue 9 September 1999 pp 53-62. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Green chemistry measures for process research and development

    Energy Technology Data Exchange (ETDEWEB)

    Constable, D.J.C.; Curzons, A.D.; Freitas dos Santos, L.M. (and others)

    2001-07-01

    A set of metrics has been developed which enables a simple assessment to be made of batch processes in terms of waste, energy usage, and chemistry efficiency. It is intended to raise awareness of green chemistry by providing a tool to assist chemists in monitoring progress in the reduction of environmental impact as they design new routes and modify processes. (author)

  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. A dictionary of chemistry

    National Research Council Canada - National Science Library

    Daintith, John

    2008-01-01

    "Fully revised and updated, the sixth edition of this popular dictionary covers all aspects of chemistry from physical chemistry to biochemisty, and boasts broader coverage in forensics, metallurgy, and geology...

  5. Organometallic Chemistry of Molybdenum.

    Science.gov (United States)

    Lucas, C. Robert; Walsh, Kelly A.

    1987-01-01

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

  6. Advanced Chemistry Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Chemistry laboratoryThe Advanced Chemistry Laboratory (ACL) is a unique facility designed for working with the most super toxic compounds known...

  7. Chemistry is Evergreen

    Indian Academy of Sciences (India)

    Srimath

    RESONANCE ⎜ March 2009. GENERAL ⎜ ARTICLE. Keywords. Green fluorescent protein,. FRET. Chemistry is Evergreen. 2008 Nobel Prize in Chemistry. Swagata Dasgupta. Swagata Dasgupta is an. Associate Professor in the. Department of Chemistry at IIT Kharagpur. Her research interests revolve around proteins and ...

  8. 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)

  9. American Association for Clinical Chemistry

    Science.gov (United States)

    ... Find the answer to your question IN CLINICAL CHEMISTRY Hs-cTnI as a Gatekeeper for Further Cardiac ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  10. Advances in electron transfer chemistry

    CERN Document Server

    Mariano, Patrick S

    1995-01-01

    Advances in Electron Transfer Chemistry, Volume 4 presents the reaction mechanisms involving the movement of single electrons. This book discusses the electron transfer reactions in organic, biochemical, organometallic, and excited state systems. Organized into four chapters, this volume begins with an overview of the photochemical behavior of two classes of sulfonium salt derivatives. This text then examines the parameters that control the efficiencies for radical ion pair formation. Other chapters consider the progress in the development of parameters that control the dynamics and reaction p

  11. 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.

  12. 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

  13. History of ``NANO''-Scale VERY EARLY Solid-State (and Liquid-State) Physics/Chemistry/Metallurgy/ Ceramics; Interstitial-Alloys Carbides/Nitrides/Borides/...Powders and Cermets, Rock Shocks, ...

    Science.gov (United States)

    Maiden, Colin; Siegel, Edward

    History of ``NANO'': Siegel-Matsubara-Vest-Gregson[Mtls. Sci. and Eng. 8, 6, 323(`71); Physica Status Solidi (a)11,45(`72)] VERY EARLY carbides/nitrides/borides powders/cermets solid-state physics/chemistry/metallurgy/ ceramics FIRST-EVER EXPERIMENTAL NANO-physics/chemistry[1968 ->Physica Status Solidi (a)11,45(`72); and EARLY NANO-``physics''/NANO-``chemistry'' THEORY(after: Kubo(`62)-Matsubara(`60s-`70s)-Fulde (`65) [ref.: Sugano[Microcluster-Physics, Springer('82 `98)

  14. Isotope and Nuclear Chemistry Division annual report, FY 1983

    Energy Technology Data Exchange (ETDEWEB)

    Heiken, J.H.; Lindberg, H.A. (eds.)

    1984-05-01

    This report describes progress in the major research and development programs carried out in FY 1983 by the Isotope and Nuclear Chemistry Division. It covers radiochemical diagnostics of weapons tests; weapons radiochemical diagnostics research and development; other unclassified weapons research; stable and radioactive isotope production, separation, and applications (including biomedical applications); element and isotope transport and fixation; actinide and transition metal chemistry; structural chemistry, spectroscopy, and applications; nuclear structure and reactions; irradiation facilities; advanced analytical techniques; development and applications; atmospheric chemistry and transport; and earth and planetary processes.

  15. The New Color of Chemistry: Green Chemistry

    OpenAIRE

    Zuhal GERÇEK

    2012-01-01

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

  16. Atmospheric chemistry and physics from air pollution to climate change

    CERN Document Server

    Seinfeld, John H

    2016-01-01

    Expanded and updated with new findings and new features Since the second edition of Seinfeld and Pandis’ classic textbook, significant progress has taken place in the field of atmospheric chemistry and physics, particularly in the areas of tropospheric chemistry, aerosols, and the science of climate change. A new edition of this comprehensive work has been developed by the renowned author team. Atmospheric Chemistry and Physics, 3rd Edition, as the previous two editions have done, provides a rigorous and comprehensive treatment of the chemistry and physics of the atmosphere – including the chemistry of the stratosphere and troposphere, aerosol physics and chemistry, atmospheric new particle formation, physical meteorology, cloud physics, global climate, statistical analysis of data, and mathematical chemical/transport models of the atmosphere. Each of these topics is covered in detail and in each area the central results are developed from first principles. In this way the reader gains a significant un...

  17. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 6, January--March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1996-05-03

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1- March 31, 1996.

  18. 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...

  19. 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

  20. BIOMASS-FUELED, SMALL-SCALE, INTEGRATED-GASIFIER, GAS-TURBINE POWER PLANT: PROGRESS REPORT ON THE PHASE 2 DEVELOPMENT

    Science.gov (United States)

    The paper reports the latest efforts to complete development of Phase 2 of a three-phase effort to develop a family of small-scale (1 to 20 MWe) biomass-fueled power plants. The concept envisioned is an air-blown pressurized fluidized-bed gasifier followed by a dry hot gas clean...

  1. USSR Report, Chemistry

    National Research Council Canada - National Science Library

    1986-01-01

    This USSR Report on Chemistry contains articles on Aerosols, Adsorption, Biochemistry, Catalysis, Chemical Industry, Coal Gasification, Electrochemistry, Explosives and Explosions, Fertilizers, Food...

  2. 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

  3. Canopy Chemistry (OTTER)

    Data.gov (United States)

    National Aeronautics and Space Administration — Canopy characteristics: leaf chemistry, specific leaf area, LAI, PAR, IPAR, NPP, standing biomass--see also: Meteorology (OTTER) for associated meteorological...

  4. Solution phase combinatorial chemistry.

    Science.gov (United States)

    Merritt, A T

    1998-06-01

    Combinatorial chemistry and parallel array synthesis techniques are now used extensively in the drug discovery process. Although published literature has been dominated by solid phase chemistry approaches, the use of solution phase techniques has also been widely explored. This review considers the advantages and disadvantages of choosing solution phase approaches in the various stages of drug discovery and optimisation, and assesses the practical issues related to these approaches. The uses of standard solution chemistry, the related liquid phase approach, and of supported materials to enhance solution phase chemistry are all illustrated by a comprehensive review of the published literature over the past three years.

  5. Elements of environmental chemistry

    National Research Council Canada - National Science Library

    Hites, R. A; Raff, Jonathan D

    2012-01-01

    ... more. Extensively revised, updated, and expanded, this second edition includes new chapters on atmospheric chemistry, climate change, and polychlorinated biphenyls and dioxins, and brominated flame retardants...

  6. Computational Chemistry for Kids

    National Research Council Canada - National Science Library

    Naef, Olivier

    2000-01-01

    This article aims to show that computational chemistry is not exclusively restricted to molecular energy and structure calculations but also includes chemical process control and reaction simulation...

  7. Green Chemistry Pedagogy

    Science.gov (United States)

    Kolopajlo, Larry

    2017-02-01

    This chapter attempts to show how the practice of chemistry teaching and learning is enriched by the incorporation of green chemistry (GC) into lectures and labs. To support this viewpoint, evidence from a wide range of published papers serve as a cogent argument that GC attracts and engages both science and nonscience students, enhances chemistry content knowledge, and improves the image of the field, while preparing the world for a sustainable future. Published pedagogy associated with green and sustainable chemistry is critically reviewed and discussed.

  8. Progress Report

    DEFF Research Database (Denmark)

    Duer, Karsten

    1999-01-01

    Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999.......Progress report describing the work carried out by the Danish participant in the ALTSET project in the period January 1999 to July 1999....

  9. Modern Trends in Inorganic Chemistry

    Indian Academy of Sciences (India)

    Unknown

    projections of research in frontier areas of inorganic chemistry, includ- ing organometallics, bio-inorganic chemistry, catalysis and materials chemistry. We do hope that the wide range of topics covered in this Issue reflect the current trends of research in inorganic chemistry in India and prac- titioners of inorganic chemistry ...

  10. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 2, January 1995--March 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, J.G.; Parekh, B.K.

    1995-05-05

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 to March 31, 1995.

  11. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report, April 1996--June 1996

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1996-07-31

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. The cost sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from April 1 - June 30, 1996.

  12. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report, No. 4, July 1995--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, J.G.; Parekh, B.K.

    1995-11-06

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 29, 1995.

  13. The effects of a technology-enhanced, flexible choice science program on achievement, self-efficacy and the scale learner progression mechanism in science

    Science.gov (United States)

    Grace, Lori

    A mixed methods comparative case study of two DRG I urban high schools was used to determine the effectiveness of the Flexible Choice Science Program (FCSP) at producing equitable learning outcomes in students. FCSP recognized both 'among and within learner' differences, while allowing the teacher the semblance of a single lesson. Program sequencing, a differentiated technology platform and allowances for student control and creativity, allowed learners to progress from novice to master at their own pace. Results showed that holistic participation in FCSP by School A students led to significant positive learning effects, particularly for low ability learners. Results of this study challenge current educational grouping techniques that have resulted in inequity, by demonstrating that when students group themselves, their success increases by more than 100%. Results of this research also challenge common notion that cognition most defines student potential by demonstrating that student affect most influences learning.

  14. Protostellar accretion traced with chemistry

    DEFF Research Database (Denmark)

    Frimann, Søren; Jørgensen, Jes Kristian; Padoan, Paolo

    2016-01-01

    used foranalysing the observations. Methods: Simple freeze-out andsublimation chemistry is added to the simulation, and syntheticC18O line cubes are created for a large number of simulatedprotostars. The spatial extent of C18O is measured for thesimulated protostars and compared directly to a sample...... by infall from the larger scales of the molecular cloud, anddo not include any disk physics. The discrepancy between simulation andobservations is taken as support for the necessity of disks, even indeeply embedded objects, to produce episodic accretion events ofsufficient frequency and amplitude....

  15. Modeling the chemistries of technical molecular plasmas

    Science.gov (United States)

    Munro, James J.; Tennyson, Jonathan; Brown, Daniel B.; Varambhia, Hemal N.; Doss, Natasha

    2008-10-01

    Plasma chemistries, especially for molecular gases, are complicated. With a limited amount of molecular data available, it is hard to model these plasmas accurately; just a couple of feedstock gases can lead to a minimal model containing perhaps dozens of gas-phase species. The possible gas-phase and surface reactions that can occur could be in the tens of thousands; less than a hundred are typically used in chemistry models. Understanding the importance of various species and reactions to a chemical model is vital. Here we present the progress on constructing a package (Quantemol-P)[1] to simplify and automate the process of building and analyzing plasma chemistries e.g. SF6/O2, CF4/O2 and O2/He. [1] J.J. Munro, J. Tennyson, J. Vac. Sci. Tech. A, accepted

  16. Diversity in Medicinal Chemistry.

    Science.gov (United States)

    Peralta, David

    2018-01-08

    The wide world of medicinal chemistry: We look back at our activities in 2017, particularly the expansion of the journal's scope to nanomedicine and why we need a more inclusive medicinal chemistry journal. Additionally, we look at upcoming special issues and developments for ChemPubSoc Europe in 2018. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. 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…

  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. 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...

  20. Movies in Chemistry Education

    Science.gov (United States)

    Pekdag, Bulent; Le Marechal, Jean-Francois

    2010-01-01

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

  1. 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)

  2. Chemistry is Evergreen

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 3. Chemistry is Everygreen - 2008 Nobel Prize in Chemistry. Swagata Dasgupta. General Article Volume 14 Issue 3 March 2009 pp 248-258. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

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

  4. Transuranic Computational Chemistry.

    Science.gov (United States)

    Kaltsoyannis, Nikolas

    2018-02-26

    Recent developments in the chemistry of the transuranic elements are surveyed, with particular emphasis on computational contributions. Examples are drawn from molecular coordination and organometallic chemistry, and from the study of extended solid systems. The role of the metal valence orbitals in covalent bonding is a particular focus, especially the consequences of the stabilization of the 5f orbitals as the actinide series is traversed. The fledgling chemistry of transuranic elements in the +II oxidation state is highlighted. Throughout, the symbiotic interplay of experimental and computational studies is emphasized; the extraordinary challenges of experimental transuranic chemistry afford computational chemistry a particularly valuable role at the frontier of the periodic table. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Large scale solubilization of coal and bioconversion to utilizable energy. Eighth quarterly technical progress report, July 1, 1995--September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, N.C.

    1996-02-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, we plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. We also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  6. A comparison of impulse drying to double felted pressing on pilot- scale shoe presses and roll presses. Progress report, No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Orloff, D.I.

    1992-08-01

    Pilot-scale shoe press and roll press experiments have been conducted to compare impulse drying and double felted pressing. Both ceramic coated and Beloit Type C press rolls have been evaluated. The experiments show that impulse drying can provide significantly higher outgoing solids than double felled pressing at the same impulse. For example, at an impulse of 0.234 MPa seconds (34 psi seconds), sheets at an ingoing solids of 52% were impulse dried (using the Beloit Type C press roll) to 68% solids while optimized double felled pressing could only yield press dryness of, at most, 60%.

  7. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    Science.gov (United States)

    Murfin, Brian

    2009-01-01

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

  8. Subsurface high-resolution definition of subsurface heterogeneity for understanding the biodynamics of natural field systems: Advancing the ability for scaling to field conditions. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Majer, E.L.

    1997-01-01

    'This research is an integrated physical (geophysical and hydrologic) and microbial study using innovative geophysical imaging and microbial characterization methods to identify key scales of physical heterogeneities that affect the biodynamics of natural subsurface environments. Data from controlled laboratory and in situ experiments at the INEEL Test Area North (TAN) site are being used to determine the dominant physical characteristics (lithologic, structural, and hydrologic) that can be imaged in situ and correlated with microbial properties. Emphasis is being placed on identifying fundamental scales of variation of physical parameters that control transport behavior relative to predicting subsurface microbial dynamics. The outcome will be an improved understanding of the relationship between physical and microbial heterogeneity, thus facilitating the design of bioremediation strategies in similar environments. This work is an extension of basic research on natural heterogeneity first initiated within the DOE/OHER Subsurface Science Program (SSP) and is intended to be one of the building blocks of an integrated and collaborative approach with an INEEL/PNNL effort aimed at understanding the effect of physical heterogeneity on transport properties and biodynamics in natural systems. The work is closely integrated with other EMSP projects at INEEL (Rick Colwell et al.) and PNNL (Fred Brockman and Jim Fredrickson).'

  9. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report No. 5, October--December, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, J.G.; Parekh, B.K.

    1996-02-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74{mu}m) clean coal. Economical dewatering of an ultrafine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the the University of Kentucky Center for Applied Energy Research will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high sulfur and low sulfur clean coal. Accomplishments for the past quarter are described.

  10. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report 3, April--June 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groppo, J.G.; Parekh, B.K.

    1995-08-05

    Economical dewatering of an ultra-fine clean coal product to a 20% or lower level moisture will be an important step in successful implementation of the advanced fine coal cleaning processes. The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept (POC) scale of 1 to 2 tph. The novel surface modification technique developed at the UKCAER will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high sulfur and low sulfur clean coal. The Mayflower Plant processes coals from five different seams, thus the dewatering studies results could be generalized for most of the bituminous coals. During this quarter, addition of reagents such as ferric ions and a novel concept of in-situ polymerization (ISP) was studied in the laboratory. Using the ISP approach with vacuum filtration provided 25% moisture filter cake compared to 65.5% moisture obtained conventionally without using the ISP. A series of dewatering tests were conducted using the Andritz hyperbaric pilot filter unit with high sulfur clean coal slurry.

  11. Progressive Business

    DEFF Research Database (Denmark)

    Christiansen, Christian O.

    2016-01-01

    Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015.......Guest Post to the Society for U.S. Intellectual History Blog. Brief introduction to the book Progressive Business: An Intellectual History of the Role of Business in American Society, Oxford U.P., 2015....

  12. Annual Report 1984. Chemistry Department

    DEFF Research Database (Denmark)

    Funck, Jytte; Nielsen, Ole John

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

  13. POC-scale testing of an advanced fine coal dewatering equipment/technique: Quarterly technical progress report No. 9, October 1996--December 1996

    Energy Technology Data Exchange (ETDEWEB)

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1997-01-21

    The advanced fine-coal cleaning techniques such as column flotation, recovers a low-ash ultra-fine size clean-coal product. However, economical dewatering of the clean coal product to less than 20 percent moisture using conventional technology is difficult. This research program objective is to evaluate a novel coal surface modification technique developed at the University of Kentucky Center for Applied Energy Research in conjunction with conventional and advanced dewatering technique at a pilot scale at the Powell Mountain Coal Company`s Mayflower preparation plant located in St. Charles, VA. During this quarter in the laboratory dewatering studies were conducted using copper and aluminum ions showed that for the low sulfur clean coal slurry addition of 0.1 Kg/t of copper ions was effective in lowering the filter cake moisture from 29 percent to 26.3 percent. Addition of 0.3 Kg/t of aluminum ions provided filter cake with 28 percent moisture. For the high sulfur clean coal slurry 0.5 Kg/t of copper and 0.1 Kg/t of aluminum ions reduced cake moisture from 30.5 percent to 28 percent respectively. Combined addition of anionic (10 g/t) and cationic (10 g/t) flocculants was effective in providing a filter cake with 29.8 percent moisture. Addition of flocculants was not effective in centrifuge dewatering. In pilot scale screen bowl centrifuge dewatering studies it was found that the clean coal slurry feed rate of 30 gpm was optimum to the centrifuge, which provided 65 percent solids capture. Addition of anionic or cationic flocculants was not effective in lowering of filter cake moisture, which remained close to 30 percent for both clean coal slurries.

  14. Updating the Geomagnetic Polarity Time Scale with Marine Magnetic Anomalies (Chrons C13-C33, 33-83 Ma): A Progress Report

    Science.gov (United States)

    Quigley, K. W.; Malinverno, A.

    2016-12-01

    Marine magnetic anomalies are found in ocean basins worldwide, and are the result of the magnetization of basaltic rocks formed at seafloor spreading centers. Because the earth's geomagnetic field has reversed throughout history, these detected anomalies record the history of reversals on the flanks of mid-ocean ridges. Magnetic anomalies define the geometry of magnetized polarity blocks in the crust, and the width of these blocks combined with absolute ages and some assumptions on the variation of spreading rates can give us a Geomagnetic Polarity Time Scale (GPTS). Time scales are important in many fields of the earth sciences to determine past rates of change, correlate geological events, and constrain the history of seafloor spreading and plate motion. Our goal is to determine an improved GPTS for the Eocene-Late Cretaceous (Chrons C13-C33). The current GPTS is based on an assumption of smoothly varying spreading rates in the South Atlantic. To better constrain the duration of polarity chrons, we will minimize spreading rate fluctuations in several regions worldwide besides the South Atlantic. Our work thus far has focused on methods of analysis for the marine magnetic anomaly data. The Pacific-Antarctic ridge was chosen as a starting point for the project because of new data and clear anomalies in mid to high latitudes. In our analysis, we select magnetic anomaly data from cruises, project data onto a plate motion flow line, identify anomalies, and compare modeled and measured anomalies. We apply a Monte Carlo sampling method that allows us to estimate start and end distances along a flow line for polarity chrons in each ship track, and quantify the uncertainty of those distances. Using the estimated block model distances, we can determine how spreading rates change between chrons along each ship track for any given GPTS. With the method we developed, our goal is to use block model distances from several spreading centers to determine a GPTS that minimizes the

  15. Genetic epidemiology of bladder cancer: scaling up in the identification of low-penetrance genetic markers of bladder cancer risk and progression.

    Science.gov (United States)

    Malats, Núria

    2008-09-01

    Bladder cancer is an increasingly important international public health problem. As a multifactorial disease, both environmental and genetic factors are involved in its development and progression. This neoplasm is a paradigm for the participation of low-penetrance genetic variants (GSTM1-null and NAT2-slow) and provides the best established gene-environment interaction in cancer (NAT2-slow * tobacco). Genetic variants in nucleotide excision and double strand break DNA repair pathways have provided promising results, ERCC2-XPD rs238406 being the most consistent variant associated with an increased of bladder cancer risk, by itself and by interacting with tobacco. Variants in other pathways such as cell-cycle control, 1-C metabolism and inflammation have been studied, although the results are inconsistent. Three very large whole genome association studies are being undertaken using the same genotyping platform. Their results will be available soon. Genetic variants have seldom been considered as markers of prognosis or response to therapy in this tumour. The results of these studies are inconclusive. Other issues that need to be addressed are the role of genetic variants in different population subgroups--defined by ethnicity, gender and age, among others--and the association with bladder cancer subphenotypes according to clinical, pathological and molecular characteristics of the tumour. This endeavour can only be achieved by integrating multidisciplinary tools and information. Can this information be applied better to identify high-risk populations? Can the information be used to better assess prognosis or predict response to therapy? These questions require large, well-designed, multicentre studies to be conducted. Funding agencies should be aware of these needs.

  16. Developing a scorecard to assess global progress in scaling up diarrhea control tools: a qualitative study of academic leaders and implementers.

    Directory of Open Access Journals (Sweden)

    Alexander Anthony Rosinski

    Full Text Available BACKGROUND: In 2010, diarrhea caused 0.75 million child deaths, accounting for nearly 12% of all under-five mortality worldwide. Many evidence-based interventions can reduce diarrhea mortality, including oral rehydration solution (ORS, zinc, and improved sanitation. Yet global coverage levels of such interventions remain low. A new scorecard of diarrhea control, showing how different countries are performing in their control efforts, could draw greater attention to the low coverage levels of proven interventions. METHODS: We conducted in-depth qualitative interviews with 21 experts, purposively sampled for their relevant academic or implementation expertise, to explore their views on (a the value of a scorecard of global diarrhea control and (b which indicators should be included in such a scorecard. We then conducted a ranking exercise in which we compiled a list of all 49 indicators suggested by the experts, sent the list to the 21 experts, and asked them to choose 10 indicators that they would include and 10 that they would exclude from such a scorecard. Finally, we created a "prototype" scorecard based on the 9 highest-ranked indicators. RESULTS: Key themes that emerged from coding the interview transcripts were: a scorecard could facilitate country comparisons; it could help to identify best practices, set priorities, and spur donor action; and it could help with goal-setting and accountability in diarrhea control. The nine highest ranking indicators, in descending order, were ORS coverage, rotavirus vaccine coverage, zinc coverage, diarrhea-specific mortality rate, diarrhea prevalence, proportion of population with access to improved sanitation, proportion with access to improved drinking water, exclusive breastfeeding coverage, and measles vaccine coverage. CONCLUSION: A new scorecard of global diarrhea control could help track progress, focus prevention and treatment efforts on the most effective interventions, establish transparency and

  17. Presidential Green Chemistry Challenge: 2012 Greener Reaction Conditions Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 2012 award winner, Cytec Industries, developed the MAX HT sodalite scale inhibitor for heat exchangers and pipes in the Bayer process, which converts bauxite into alumina.

  18. Mathematics for physical chemistry

    CERN Document Server

    Mortimer, Robert G

    2013-01-01

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

  19. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

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

  20. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    Although spatial structures can play a crucial role in chemical systems and can drastically alter the outcome of reactions, the traditional framework of artificial chemistry is a well-stirred tank reactor with no spatial representation in mind. Advanced method development in physical chemistry has...... made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  1. Experiments in physical chemistry

    CERN Document Server

    Wilson, J M; Denaro, A R

    1968-01-01

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

  2. High-temperature gas-cooled reactor base-technology program. Progress report, January 1, 1974--June 30, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Coobs, J.H.; Kasten, P.R.

    1976-11-01

    Progress is reported in the following areas: PCRV development, studies on structural materials, fission product technology studies, kernel migration and irradiated fuel chemistry, coolant chemistry (steam-graphite reactions), fuel qualification, and characterization and standardization of graphite.

  3. Chemistry of fast electrons

    Science.gov (United States)

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

    2009-01-01

    A chemicurrent is a flux of fast (kinetic energy ≳ 0.5−1.3 eV) metal electrons caused by moderately exothermic (1−3 eV) chemical reactions over high work function (4−6 eV) metal surfaces. In this report, the relation between chemicurrent and surface chemistry is elucidated with a combination of top-down phenomenology and bottom-up atomic-scale modeling. Examination of catalytic CO oxidation, an example which exhibits a chemicurrent, reveals 3 constituents of this relation: The localization of some conduction electrons to the surface via a reduction reaction, 0.5 O2 + δe− → Oδ− (Red); the delocalization of some surface electrons into a conduction band in an oxidation reaction, Oδ− + CO → CO2δ− → CO2 + δe− (Ox); and relaxation without charge transfer (Rel). Juxtaposition of Red, Ox, and Rel produces a daunting variety of metal electronic excitations, but only those that originate from CO2 reactive desorption are long-range and fast enough to dominate the chemicurrent. The chemicurrent yield depends on the universality class of the desorption process and the distribution of the desorption thresholds. This analysis implies a power-law relation with exponent 2.66 between the chemicurrent and the heat of adsorption, which is consistent with experimental findings for a range of systems. This picture also applies to other oxidation-reduction reactions over high work function metal surfaces. PMID:19561296

  4. Progress Report No. 65 Aug. 15-Sept. 15, 1948

    Energy Technology Data Exchange (ETDEWEB)

    Various

    1948-09-15

    This is a progress report on the following: (1) 184-inch Cyclotron Program; (2) 60-inch Cyclotron Operation; (3) Synchrotron Program; (4) Linear Accelerator Operation; (5) Experimental Physics; (6) Theoretical Physics; (7) Isotope Separation Program; (8) Chemistry; (9) Medical Physics; and (10) Health Chemistry and Physics.

  5. Subsurface high resolution definition of subsurface heterogeneity for understanding the biodynamics of natural field systems: Advancing the ability for scaling to field conditions. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Majer, E.L. [Lawrence Berkeley National Lab., CA (US); Brockman, F.J. [Pacific Northwest National Lab., Richland, WA (US)

    1998-06-01

    'This research is an integrated physical (geophysical and hydrologic) and microbial study using innovative geophysical imaging and microbial characterization methods to identify key scales of physical heterogeneities that affect the biodynamics of natural subsurface environments. Data from controlled laboratory and in-situ experiments at the INEEL Test Area North (TAN) site are being used to determine the dominant physical characteristics (lithologic, structural, and hydrologic) that can be imaged in-situ and correlated with microbial properties. The overall goal of this research is to contribute to the understanding of the interrelationships between transport properties and spatially varying physical, chemical, and microbiological heterogeneity. The outcome will be an improved understanding of the relationship between physical and microbial heterogeneity, thus facilitating the design of bioremediation strategies in similar environments. This report summarizes work as of May 1998, the second year of the project. This work is an extension of basic research on natural heterogeneity first initiated within the DOE/OHER Subsurface Science Program (SSP) and is intended to be one of the building blocks of an integrated and collaborative approach with an INEEL/PNNL effort aimed at understanding the effect of physical heterogeneity on transport properties and biodynamics in natural systems. The work is closely integrated with other EMSP projects at INEEL (Rick Colwell et al.) and PNNL (Fred Brockman and Jim Fredrickson).'

  6. Monitoring the progression of calcium and protein solubilisation as affected by calcium chelators during small-scale manufacture of casein-based food matrices.

    Science.gov (United States)

    McIntyre, Irene; O'Sullivan, Michael; O'Riordan, Dolores

    2017-12-15

    Calcium and protein solubilisation during small-scale manufacture of semi-solid casein-based food matrices was investigated and found to be very different in the presence or absence of calcium chelating salts. Calcium concentrations in the dispersed phase increased and calcium-ion activity (ACa++) decreased during manufacture of the matrices containing calcium chelating salts; with ∼23% of total calcium solubilised by the end of manufacture. In the absence of calcium chelating salts, these concentrations were significantly lower at equivalent processing times and remained unchanged as did ACa++, throughout manufacture. The protein content of the dispersed phase was low (≤3% of total protein), but was significantly higher for matrices containing calcium chelating salts. This study elucidates the critical role of calcium chelating salts in modulating casein hydration and dispersion and gives an indication of the levels of soluble calcium and protein required to allow matrix formation during manufacture of casein-based food structures e.g. processed and analogue cheese. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Frontiers in Atmospheric Chemistry Modelling

    Science.gov (United States)

    Colette, Augustin; Bessagnet, Bertrand; Meleux, Frederik; Rouïl, Laurence

    2013-04-01

    The first pan-European kilometre-scale atmospheric chemistry simulation is introduced. The continental-scale air pollution episode of January 2009 is modelled with the CHIMERE offline chemistry-transport model with a massive grid of 2 million horizontal points, performed on 2000 CPU of a high performance computing system hosted by the Research and Technology Computing Center at the French Alternative Energies and Atomic Energy Commission (CCRT/CEA). Besides the technical challenge, which demonstrated the robustness of the selected air quality model, we discuss the added value in terms of air pollution modelling and decision support. The comparison with in-situ observations shows that model biases are significantly improved despite some spurious added spatial variability attributed to shortcomings in the emission downscaling process and coarse resolution of the meteorological fields. The increased spatial resolution is clearly beneficial for the detection of exceedances and exposure modelling. We reveal small scale air pollution patterns that highlight the contribution of city plumes to background air pollution levels. Up to a factor 5 underestimation of the fraction of population exposed to detrimental levels of pollution can be obtained with a coarse simulation if subgrid scale correction such as urban increments are ignored. This experiment opens new perspectives for environmental decision making. After two decades of efforts to reduce air pollutant emissions across Europe, the challenge is now to find the optimal trade-off between national and local air quality management strategies. While the first approach is based on sectoral strategies and energy policies, the later builds upon new alternatives such as urban development. The strategies, the decision pathways and the involvement of individual citizen differ, and a compromise based on cost and efficiency must be found. We illustrated how high performance computing in atmospheric science can contribute to this

  8. Recent advances in the chemistry and biology of pyridopyrimidines.

    Science.gov (United States)

    Buron, F; Mérour, J Y; Akssira, M; Guillaumet, G; Routier, S

    2015-05-05

    The interest in pyridopyrimidine cores for pharmaceutical products makes this scaffold a highly useful building block for organic chemistry. These derivatives have found applications in various areas of medicine such as anticancer, CNS, fungicidal, antiviral, anti-inflammatory, antimicrobial, and antibacterial therapies. This review mainly focuses on the progress achieved since 2004 in the chemistry and biological activity of pyridopyrimidines. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  9. Recent advances in the chemistry of organic thiocyanates.

    Science.gov (United States)

    Castanheiro, Thomas; Suffert, Jean; Donnard, Morgan; Gulea, Mihaela

    2016-02-07

    Organic thiocyanates are important synthetic intermediates to access valuable sulfur-containing compounds. In this review the different methods for their preparation and their synthetic applications will be presented. The literature of the last 15 years will be covered, highlighting selected recent advances in the chemistry of this class of compounds. We hope to offer chemists the tools to have a good grasp of this singular functionality and open the door to further progress in this chemistry.

  10. The chemistry of energy conversion and storage.

    Science.gov (United States)

    Su, Dang Sheng

    2014-05-01

    What's in store: The sustainable development of our society requires the conversion and storage of renewable energy, and these should be scaled up to serve the global primary energy consumption. This special issue on "The Chemistry of Energy Conversion and Storage", assembled by guest editor Dangsheng Su, contains papers dealing with these aspects, and highlights important developments in the chemistry of energy conversion and storage during the last two years. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Chemistry with a Peel.

    Science.gov (United States)

    Borer, Londa; Larsen, Eric

    1997-01-01

    Presents experiments that introduce natural product chemistry into high school classrooms. In the laboratory activities, students isolate and analyze the oil in orange peels. Students also perform a steam distillation and learn about terpenes. (DDR)

  12. Indicators: Soil Chemistry

    Science.gov (United States)

    The chemical makeup of the soil can provide information on wetland condition, wetland water quality and services being provided by the wetland ecosystem. Analyzing soil chemistry reveals if the soil is contaminated with a toxic chemical or heavy metal.

  13. Microfluidics in inorganic chemistry.

    Science.gov (United States)

    Abou-Hassan, Ali; Sandre, Olivier; Cabuil, Valérie

    2010-08-23

    The application of microfluidics in chemistry has gained significant importance in the recent years. Miniaturized chemistry platforms provide controlled fluid transport, rapid chemical reactions, and cost-saving advantages over conventional reactors. The advantages of microfluidics have been clearly established in the field of analytical and bioanalytical sciences and in the field of organic synthesis. It is less true in the field of inorganic chemistry and materials science; however in inorganic chemistry it has mostly been used for the separation and selective extraction of metal ions. Microfluidics has been used in materials science mainly for the improvement of nanoparticle synthesis, namely metal, metal oxide, and semiconductor nanoparticles. Microfluidic devices can also be used for the formulation of more advanced and sophisticated inorganic materials or hybrids.

  14. Supplemental instruction in chemistry

    Science.gov (United States)

    Lundeberg, Mary A.

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

  15. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 7. Electrostatics in Chemistry - Molecular Electrostatic Potential: Visualization and Topography. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 7 July 1999 pp 14-23 ...

  16. Development & testing of industrial scale, coal fired combustion system, phase 3. Eighth quarterly technical progress report, 1 October, 1993--31 December, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Zauderer, B.

    1994-01-31

    The primary objective of the present Phase 3 effort is to perform the final testing at a 20 MMBtu/hr commercial scale of an air cooled, slagging coal combustor for application to industrial steam boilers and power plants. The focus of the test effort will be on combustor durability, automatic control of the combustor`s operation, and optimum environmental control of emissions inside the combustor. In connection with the latter, the goal is to achieve 0.4 lb/MMBtu of SO{sub 2} emissions, 0.2 lb/MMBtu of NO{sub x} emissions, and 0.02 lb particulates/MMBtu. Meeting the particulate goal will require the use of a baghouse or electrostatic precipitator to augment the nominal slag retention in the combustor. The NO{sub x} emission goal will require a modest improvement over maximum reduction achieved to date in the combustor to a level of 0.26 lb/MMBtu. To reach the SO{sub 2} emissions goal may require a combination of sorbent injection inside the combustor and sorbent injection inside the boiler, especially in high (>3.5%) sulfur coals. Prior to the initiation of the project, SO{sub 2} levels as low as 0.6 lb/MMBtu, equal to 81% reduction in 2% sulfur coals, were measured with boiler injection of calcium hydrate. The final objective is to define suitable commercial power or steam generating systems to which the use of the air cooled combustor offers significant technical and economic benefits. In implementing this objective both simple steam generation and combined gas turbine-steam generation systems will be considered.

  17. Applications of supramolecular chemistry

    CERN Document Server

    Schneider, Hans-Jörg

    2012-01-01

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

  18. Fundamentals of quantum chemistry

    CERN Document Server

    House, J E

    2004-01-01

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

  19. Tropical Soil Chemistry

    DEFF Research Database (Denmark)

    Borggaard, Ole K.

    and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...

  20. Impact of surface chemistry

    Science.gov (United States)

    Somorjai, Gabor A.; Li, Yimin

    2011-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized. PMID:20880833

  1. Magnetization of exsolution intergrowths of hematite and ilmenite: Mineral chemistry, phase relations, and magnetic properties of hemo-ilmenite ores with micron- to nanometer-scale lamellae from Allard Lake, Quebec

    DEFF Research Database (Denmark)

    McEnroe, S.A.; Robinson, P.; Langenhorst, F.

    2007-01-01

    . To understand the magnetism and evolution of the exsolution lamellae, the microstructures and nanostructures were studied using scanning electron microscopy and transmission electron microscopy (TEM), phase chemistry, and relations between mineral chemistry and the hematite-ilmenite phase diagram. Cycles...... of exsolution during slow cooling resulted in lamellae down to 1 -2 nm thick. Combined electron microprobe, TEM, and X-ray diffraction (XRD) results indicate that hematite hosts reached a composition approximately ilmenite (Ilm) 14.4, and ilmenite hosts similar to Ilm 98. The bulk of the very stable NRM, which...... shows thermal unblocking similar to 595 -620 degrees C, was acquired during final exsolution in the two-phase region canted antiferromagnetic R(3) over bar c hematite + R (3) over bar ilmenite. Hysteresis measurements show a very strong anisotropy, with a stronger coercivity normal to, than parallel to...

  2. The effects of atmospheric chemistry on radiation budget in the Community Earth Systems Model

    Science.gov (United States)

    Choi, Y.; Czader, B.; Diao, L.; Rodriguez, J.; Jeong, G.

    2013-12-01

    The Community Earth Systems Model (CESM)-Whole Atmosphere Community Climate Model (WACCM) simulations were performed to study the impact of atmospheric chemistry on the radiation budget over the surface within a weather prediction time scale. The secondary goal is to get a simplified and optimized chemistry module for the short time period. Three different chemistry modules were utilized to represent tropospheric and stratospheric chemistry, which differ in how their reactions and species are represented: (1) simplified tropospheric and stratospheric chemistry (approximately 30 species), (2) simplified tropospheric chemistry and comprehensive stratospheric chemistry from the Model of Ozone and Related Chemical Tracers, version 3 (MOZART-3, approximately 60 species), and (3) comprehensive tropospheric and stratospheric chemistry (MOZART-4, approximately 120 species). Our results indicate the different details in chemistry treatment from these model components affect the surface temperature and impact the radiation budget.

  3. Attitudes towards chemistry among engineering students

    Science.gov (United States)

    Olivo Delgado, Carlos J.

    The attitudes towards chemistry of the engineering students enrolled in an introductory course at the Polytechnic University of Puerto Rico were explored (n = 115). A mixed methodology was used in an exploratory-oriented research approach. The first stage consisted of the administration of a Likert scale attitudinal survey which was validated during the study's design process. The survey allowed collecting information about the participant's attitudes towards their personal opinion, their perspectives about peer's or relatives' opinion, relevant aspects of the discipline, and difficulty-increasing factors in the chemistry course. The scale internal reliability was measured in a pilot study with a convenience simple, obtaining an acceptable coefficient (Cronbach alpha = 0.731). Survey results evidenced a mainly neutral attitude towards the chemistry course, not highly negative or highly positive, in contrast with other studies in this field. On the other hand, the normality hypothesis was tested for the scores obtained by participants in the survey. Although the pilot study sample had an approximately normal distribution, the scores in obtained by the participants in the survey failed the normality test criteria. The second stage of the study was accomplished using a case study. Among the survey participants, some students were invited to in-depth interviews to elucidate the reasons why they have certain attitudes towards chemistry. Study time, instructor, motivation, term of study, and course schedule are the factors that interviewees agreed as contributors to success or failure in the chemistry course. Interview's participants emphasized that study time is determinant to pass the class. This methodological approach, quantitative followed by qualitative, was useful in describing the attitudes towards chemistry among university students of engineering.

  4. Nanoinformatics: an emerging area of information technology at the intersection of bioinformatics, computational chemistry and nanobiotechnology.

    Science.gov (United States)

    González-Nilo, Fernando; Pérez-Acle, Tomás; Guínez-Molinos, Sergio; Geraldo, Daniela A; Sandoval, Claudia; Yévenes, Alejandro; Santos, Leonardo S; Laurie, V Felipe; Mendoza, Hegaly; Cachau, Raúl E

    2011-01-01

    After the progress made during the genomics era, bioinformatics was tasked with supporting the flow of information generated by nanobiotechnology efforts. This challenge requires adapting classical bioinformatic and computational chemistry tools to store, standardize, analyze, and visualize nanobiotechnological information. Thus, old and new bioinformatic and computational chemistry tools have been merged into a new sub-discipline: nanoinformatics. This review takes a second look at the development of this new and exciting area as seen from the perspective of the evolution of nanobiotechnology applied to the life sciences. The knowledge obtained at the nano-scale level implies answers to new questions and the development of new concepts in different fields. The rapid convergence of technologies around nanobiotechnologies has spun off collaborative networks and web platforms created for sharing and discussing the knowledge generated in nanobiotechnology. The implementation of new database schemes suitable for storage, processing and integrating physical, chemical, and biological properties of nanoparticles will be a key element in achieving the promises in this convergent field. In this work, we will review some applications of nanobiotechnology to life sciences in generating new requirements for diverse scientific fields, such as bioinformatics and computational chemistry.

  5. [Progress in metal-organic frameworks].

    Science.gov (United States)

    Zhai, Rui; Jiao, Fenglong; Lin, Hongjun; Hao, Feiran; Li, Jiabin; Yan, Hui; Li, Nannan; Wang, Huanhuan; Jin, Zuyao; Zhang, Yangjun; Qian, Xiaohong

    2014-02-01

    Metal-organic frameworks (MOFs) are a class of crystalline materials built from organic binding ligands and metal ions through self-assembly. Currently, MOFs have drawn a growing interest among the scientific teams of various fields. Compared with conventional inorganic porous materials, MOFs possess larger specific surface areas, higher porosity and diversity of structures and functions, thus many potential applications have been proposed in the domains of gas adsorption and separation, sensors, drug delivery, catalysis or others. The combinations of MOFs and other materials such as graphene oxide, magnetic nanoparticles have obvious advantages in adsorption and separation. The appearance of novel materials greatly promotes interdisciplinary developments such as organic chemistry, inorganic chemistry, coordination chemistry, materials chemistry, life science and computer science. This article reviews the progress of MOFs in recent years, including the characteristics of MOFs, advances at home and abroad, applications, central issues of compound MOFs and the prospects in the future.

  6. Chemistry beyond positivism.

    Science.gov (United States)

    Brandt, Werner W

    2003-05-01

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

  7. Chemistry of nuclear resources, technology, and waste

    Energy Technology Data Exchange (ETDEWEB)

    Keller, O.L. Jr.

    1978-01-01

    Chemistry is being called on today to obtain useful results in areas that have been found very difficult for it in the past, but new instrumentation and new theories are allowing much progress. The area of hydrolytic phenomena and colloid chemistry, as exemplified by the plutonium polymer problem, is clearly entering a new phase in which it can be studied in a much more controlled and understandable manner. The same is true of the little studied interfacial regions, where so much important chemistry occurs in solvent extraction and other systems. The studies of the adsorption phenomena on clays are an illustration of the new and useful modeling of geochemical phenomena that is now possible. And finally, the chemist is called upon to participate in the developement and evaluation of models for nuclear waste isolation requiring extrapolations of hundreds to hundreds of thousands of years into the future. It is shown that chemistry may be useful in keeping the extrapolations in the shorter time spans, and also in selecting the best materials for containment. 36 figures.

  8. Bioorthogonal chemistry: strategies and recent development

    Science.gov (United States)

    Ramil, Carlo P.; Lin, Qing

    2013-01-01

    The use of covalent chemistry to track biomolecules in their native environment—a focus of bioorthogonal chemistry—has received considerable interests recently among chemical biologists and organic chemists alike. To facilitate wider adoption of bioorthogonal chemistry in biomedical research, a central effort in the last few years has been focused on the optimization of a few known bioorthogonal reactions, particularly with respective to reaction kinetics improvement, novel genetic encoding systems, and fluorogenic reactions for bioimaging. During these optimizations, three strategies have emerged, including the use of ring strain for substrate activation in the cycloaddition reactions, the discovery of new ligands and privileged substrates for accelerated metal-catalysed reactions, and the design of substrates with pre-fluorophore structures for rapid “turn-on” fluorescence after selective bioorthogonal reactions. In addition, new bioorthogonal reactions based on either modified or completely unprecedented reactant pairs have been reported. Finally, increasing attention has been directed toward the development of mutually exclusive bioorthogonal reactions and their applications in multiple labeling of a biomolecule in cell culture. In this feature article, we wish to present the recent progress in bioorthogonal reactions through the selected examples that highlight the above-mentioned strategies. Considering increasing sophistication in bioorthogonal chemistry development, we strive to project several exciting opportunities where bioorthogonal chemistry can make a unique contribution to biology in near future. PMID:24145483

  9. Cellular uptake: lessons from supramolecular organic chemistry.

    Science.gov (United States)

    Gasparini, Giulio; Bang, Eun-Kyoung; Montenegro, Javier; Matile, Stefan

    2015-07-04

    The objective of this Feature Article is to reflect on the importance of established and emerging principles of supramolecular organic chemistry to address one of the most persistent problems in life sciences. The main topic is dynamic covalent chemistry on cell surfaces, particularly disulfide exchange for thiol-mediated uptake. Examples of boronate and hydrazone exchange are added for contrast, comparison and completion. Of equal importance are the discussions of proximity effects in polyions and counterion hopping, and more recent highlights on ring tension and ion pair-π interactions. These lessons from supramolecular organic chemistry apply to cell-penetrating peptides, particularly the origin of "arginine magic" and the "pyrenebutyrate trick," and the currently emerging complementary "disulfide magic" with cell-penetrating poly(disulfide)s. They further extend to the voltage gating of neuronal potassium channels, gene transfection, and the delivery of siRNA. The collected examples illustrate that the input from conceptually innovative chemistry is essential to address the true challenges in biology beyond incremental progress and random screening.

  10. Collaborative Physical Chemistry Projects Involving Computational Chemistry

    Science.gov (United States)

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

    2000-02-01

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

  11. 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.

  12. Air Composition and Chemistry

    Science.gov (United States)

    Brimblecombe, Peter

    1996-01-01

    This book is about the atmosphere and humanity's influence on it. For this new edition, Brimblecombe has rewritten and updated much of the book. In the early chapters, he discusses the geochemical, biological and maritime sources of the trace gases. Next, he examines the chemistry of atmospheric gases, suspended particles, and rainfall. After dealing with the natural atmosphere, he examines the sources of air pollution and its effects, with all scenarios updated from the last edition. Scenarios include decline in health, damage to plants and animals, indoor pollution, and acid rain. The final chapters, also revised, are concerned with the chemistry and evolution of the atmospheres of the planets of the solar system. Students with an interest in chemistry and the environmental sciences will find this book highly valuable.

  13. Spins in chemistry

    CERN Document Server

    McWeeny, Roy

    2004-01-01

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

  14. Solvent effects in chemistry

    CERN Document Server

    Buncel, Erwin

    2015-01-01

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

  15. Chemistry WebBook

    Science.gov (United States)

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

  16. Dynamic Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Lisbjerg, Micke

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

  17. Chemistry in second life.

    Science.gov (United States)

    Lang, Andrew S I D; Bradley, Jean-Claude

    2009-10-23

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

  18. 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

  19. Atmospheric pseudohalogen chemistry

    OpenAIRE

    Lary, D. J.

    2004-01-01

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

  20. Chemistry in Second Life

    Directory of Open Access Journals (Sweden)

    Bradley Jean-Claude

    2009-10-01

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

  1. 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

  2. Recent progress in the chemistry of endohedral metallofullerenes.

    Science.gov (United States)

    Lu, Xing; Bao, Lipiao; Akasaka, Takeshi; Nagase, Shigeru

    2014-12-07

    Putting metal atoms or metallic clusters into fullerenes has generated a new class of hybrid molecules, defined as endohedral metallofullerenes (EMFs), possessing novel structures and fascinating properties which are different from those of empty fullerenes. In particular, it has been revealed that the chemical properties of the cage carbons of EMFs depend strongly on the nature of the internal metallic species, such as their electronic configuration, location and even motion. Since the first report describing the successful derivatization of La@C82 in 1995, great efforts have been devoted to the chemical modification of EMFs during the last two decades. Although earlier studies mainly focused on readily available species such as M@C82, M2@C80 and M3N@C80 and the related results have been systematically summarized in our previous review paper (Chem. Commun., 2011, 47, 5942-5957), recent concerns about some relatively rare EMFs have developed rapidly. Moreover, taking advantage of single crystal X-ray crystallography, we can now clearly demonstrate the mutual influences between the internal metallic species and the chemical behaviours of the surrounding cage carbons, and the addends as well. In this article, we present recent achievements in the chemical functionalization of EMFs, which were mainly published during the last four years. For consistency, we will still pay special attention to the role that the metals play in controlling the properties of the whole EMF molecules. In this review, however, we will not only focus on concrete experimental results such as X-ray crystallographic and NMR spectroscopic data but will also include computational studies which have indeed enhanced our understanding of the chemical properties of EMFs. Applicable materials based on EMFs are also mentioned but are not discussed in detail.

  3. Chemistry and Materials Science progress report, FY 1994. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    Thrust areas of the weapons-supporting research include surface science, fundamentals of the physics and processing of metals, energetic materials, etc. The laboratory directed R and D include director`s initiatives, individual projects, and transactinium science studies.

  4. Chemistry and materials science progress report, FY 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    Research is reported in the areas of surface science, fundamentals of the physics and processing of metals, energetic materials, transactinide materials and properties and other indirectly related areas of weapons research.

  5. University of Maryland Nuclear Chemistry annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Mignerey, A.C.

    1996-02-01

    The experimental efforts are divided between intermediate energy heavy ion reactions and relativistic heavy ion reactions. The three sections of each effort (6 in all) are processed separately for the data base.

  6. progress in the chemistry of marketed traditional-ly used

    African Journals Online (AJOL)

    wisdom of making this an ingredient during baking [11]- The oil is predominantly made up of carvacrol (3) and ... precise understanding of the scientific role of this plant in the brewing process is emerging only veryzttlowly. Coady in ..... which fits the rejected alternative structure described above (55) in addition to other pigml.

  7. Chemistry and Materials Science. Progress report, first half, FY 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-07-01

    Thrust areas of the weapons-supporting research are growth, structure, and reactivity of surfaces and thin films; uranium research; physics and processing of metals; energetic materials; etc. The laboratory-directed R and D include director`s initiatives and individual projects, and transactinium institute studies.

  8. Theoretical studies of hydrocarbon combustion chemistry. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, H.F. III

    1994-08-01

    The author reports here the results of DZP CISD calculations for methylcarbene. Geometry, symmetry, and vibrational modes for the radical are reported for both the singlet and the triplet state. Future work will focus on the ethyl radical-oxygen interaction relevant to hydrocarbon combustion.

  9. Nuclear chemistry progress report, September 1, 1979-August 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    Loveland, W.D.

    1980-09-01

    The work described is part of a project involving the study of low-energy (< 10 MeV/A), intermediate-energy (10 to 100 MeV/A), and relativistic (greater than or equal to 250 MeV/A) heavy-ion reactions. Changes in target fragmentation reaction mechanisms in the energy region from 10 to 100 MeV/A were characterized experimentally. Six items in this report with significant amounts of experimental data were abstracted and indexed individually. (RWR)

  10. [Chemistry for sustainable construction: 20 years of progress].

    Science.gov (United States)

    Leoni, R

    2012-01-01

    Sustainable development is based on three pillars, economic, social and environmental development. Sustainable products can be developed only by companies that grow on these pillars, but in building sustainability is often identified only with the reduction of dangerous synthetic substances. From this point of view, the efforts of the construction chemicals industry have focused on reducing emissions, dust and volatile organic compounds (VOCs), replacing, if technically possible, the most dangerous components, such as formaldehyde, phthalates, and chlorinated or aromatic solvents, and developing water-borne products with very low VOC emissions. Differences in the definition of VOC and in the methods of measurement of emissions, however, make it difficult to choose the safest product and grows in the construction industry the need to reference trusted standards and product certifications to guarantee users. At present, products labeled "bio", "eco" or "solvent free" do not necessarily mean safe products.

  11. Analytical Chemistry Laboratory progress report for FY 1992

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Heinrich, R.R.; Graczyk, D.G.; Lindahl, P.C.; Boparai, A.S.; Bass, D.A.

    1992-12-01

    The ACL activities covered IFR fuel reprocessing, corium-concrete interactions, environmental samples, wastes, WIPP support, Advanced Photon Source, H-Tc superconductors, EBWR vessel, soils, illegal drug detection, quality control, etc.

  12. Research in nuclear chemistry. Progress report. [Bio Rex-70

    Energy Technology Data Exchange (ETDEWEB)

    Choppin, Gregory R.

    1980-01-01

    The research is concerned primarily with complexes in aqueous solution of actinide elements. Actinides in the trivalent oxidation state have been studied more than species in other valence states. Similar systems have also been investigated for the trivalent lanthanides. Since 15 lanthanides can be studied using a wider variety of techniques than feasible with the actinides (e.g., NMR), comparison of these closely related families of elements using the greater amount and variety of lanthanide data provides better understanding of actinide behavior. The studies have included measurements of the thermodynamic parameters of complexation for both inorganic and organic ligands, of the kinetics of complexation, of the spectroscopic properties of complex species using f reverse arrow f electronic transitions, of the nuclear magnetic resonance spectroscopy of the complexed ligands and of binding to natural polyelectrolytes such as humic acid.

  13. Research in actinide chemistry. Progress report, 1990--1993

    Energy Technology Data Exchange (ETDEWEB)

    Choppin, G.R.

    1993-04-01

    This research studies the behavior of the actinide elements in aqueous solution. The high radioactivity of the transuranium actinides limits the concentrations which can be studied and, consequently, limits the experimental techniques. However, oxidation state analogs (trivalent lanthanides, tetravalent thorium, and hexavalent uranium) do not suffer from these limitations. Behavior of actinides in the environment are a major USDOE concern, whether in connection with long-term releases from a repository, releases from stored defense wastes or accidental releases in reprocessing, etc. Principal goal of our research was expand the thermodynamic data base on complexation of actinides by natural ligands (e.g., OH{sup {minus}}, CO{sub 3}{sup 2{minus}}, PO{sub 4}{sup 3{minus}}, humates). The research undertakes fundamental studies of actinide complexes which can increase understanding of the environmental behavior of these elements.

  14. Measuring progress

    DEFF Research Database (Denmark)

    Wahlberg, Ayo

    2007-01-01

    In recent years, sociological examinations of genetics, therapeutic cloning, neuroscience and tissue engineering have suggested that 'life itself' is currently being transformed through technique with profound implications for the ways in which we understand and govern ourselves and others...... in much the same way that mortality rates, life expectancy or morbidity rates can. By analysing the concrete ways in which human progress has been globally measured and taxonomised in the past two centuries or so, I will show how global stratifications of countries according to their states...

  15. Coupled Atmospheric Chemistry Schemes for Modeling Regional and Global Atmospheric Chemistry

    Science.gov (United States)

    Saunders, E.; Stockwell, W. R.

    2016-12-01

    Atmospheric chemistry models require chemical reaction mechanisms to simulate the production of air pollution. GACM (Global Atmospheric Chemistry Mechanism) is intended for use in global scale atmospheric chemistry models to provide chemical boundary conditions for regional scale simulations by models such as CMAQ. GACM includes additional chemistry for marine environments while reducing its treatment of the chemistry needed for highly polluted urban regions. This keeps GACM's size small enough to allow it to be used efficiently in global models. GACM's chemistry of volatile organic compounds (VOC) is highly compatible with the VOC chemistry in RACM2 allowing a global model with GACM to provide VOC boundary conditions to a regional scale model with RACM2 with reduced error. The GACM-RACM2 system of mechanisms should yield more accurate forecasts by regional air quality models such as CMAQ. Chemical box models coupled with the regional and global atmospheric chemistry mechanisms (RACM2 & GACM) will be used to make simulations of tropospheric ozone, nitric oxides, and volatile organic compounds that are produced in regional and global domains. The simulations will focus on the Los Angeles' South Coast Air Basin (SoCAB) where the Pacific Ocean meets a highly polluted urban area. These two mechanisms will be compared on the basis of simulated ozone concentrations over this marine-urban region. Simulations made with the more established RACM2 will be compared with simulations made with the newer GACM. In addition WRF-Chem will be used to simulate how RACM2 will produce regional simulations of tropospheric ozone and NOx, which can be further, analyzed for air quality impacts. Both the regional and global model in WRF-Chem will be used to predict how the concentrations of ozone and nitrogen oxides change over land and ocean. The air quality model simulation results will be applied to EPA's BenMAP-CE (Environmental Benefits Mapping & Analysis Program-Community Edition

  16. Chemistry and materials science research report

    Energy Technology Data Exchange (ETDEWEB)

    1990-05-31

    The research reported here in summary form was conducted under the auspices of Weapons-Supporting Research (WSR) and Institutional Research and Development (IR D). The period covered is the first half of FY90. The results reported here are for work in progress; thus, they may be preliminary, fragmentary, or incomplete. Research in the following areas are briefly described: energetic materials, tritium, high-Tc superconductors, interfaces, adhesion, bonding, fundamental aspects of metal processing, plutonium, synchrotron-radiation-based materials science, photocatalysis on doped aerogels, laser-induced chemistry, laser-produced molecular plasmas, chemistry of defects, dta equipment development, electronic structure study of the thermodynamic and mechanical properties of Al-Li Alloys, and the structure-property link in sub-nanometer materials.

  17. Chemistry: Experiments, Demonstrations and Other Activities Suggested for Chemistry.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    This publication is a handbook used in conjunction with the course of study in chemistry developed through the New York State Education Department and The University of the State of New York. It contains experiments, demonstrations, and other activities for a chemistry course. Areas covered include the science of chemistry, the atomic structure of…

  18. Connected Chemistry--Incorporating Interactive Simulations into the Chemistry Classroom.

    Science.gov (United States)

    Stieff, Mike; Wilensky, Uri

    2003-01-01

    Describes a novel modeling and simulation package and assesses its impact on students' understanding of chemistry. Connected Chemistry was implemented inside the NetLogo modeling environment. Using Connected Chemistry, students employed problem -solving techniques characterized by stronger attempts at conceptual understanding and logical…

  19. An Introduction to the Fundamentals of Chemistry for the Marine Engineer.

    Science.gov (United States)

    Schlenker, Richard M.

    This document describes an introduction course in the fundamentals of chemistry for marine engineers. The course is modularized, audio tutorial allowing the student to progress at his own rate while integrating laboratory and lecture materials. (SL)

  20. Myrrh--Commiphora chemistry.

    Science.gov (United States)

    Hanus, Lumír O; Rezanka, Tomás; Dembitsky, Valery M; Moussaieff, Arieh

    2005-06-01

    Myrrh and opopanax has been used throughout history in incense and as a perfume. Since Bible times it has been used for the treatment of wounds. The first attempts to identify content compounds were almost 100 years ago. In this review we discuss the present state of knowledge in the chemistry of substances of Commiphora spp.

  1. Elements of Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 1. Elements of Chemistry. Antoine-Laurent Lavoisier. Classics Volume 17 Issue 1 January 2012 pp 92-100. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/017/01/0092-0100. Author Affiliations.

  2. Chemistry and Heritage

    Science.gov (United States)

    Vittoria Barbarulo, Maria

    2014-05-01

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

  3. Concept of Green Chemistry

    Indian Academy of Sciences (India)

    Srimath

    Chemistry has provided valuable materials in the form of medi- cines, food products, cosmetics, dyes, paints, agrochemicals, biomolecules, high-tech substances like polymers, liquid crystals and nanoparticles. Chemists have used their knowledge and skill to prepare a large number of new materials which are far better.

  4. Chemistry at the Nanoscale

    Indian Academy of Sciences (India)

    Program, School of Medicine and Dentistry, University of. Rochester, New York. His research interests are in studying the structure, function, interaction and the chemistry of biomolecules as well as their assemblies and networks. Ram Ramaswamy teaches in the Schools of Physical. Sciences (SPS) and. Computational and.

  5. Chemistry in the Troposphere.

    Science.gov (United States)

    Chameides, William L.; Davis, Douglas D.

    1982-01-01

    Topics addressed in this review of chemistry in the troposphere (layer of atmosphere extending from earth's surface to altitude of 10-16km) include: solar radiation/winds; earth/atmosphere interface; kinetic studies of atmospheric reactions; tropospheric free-radical photochemistry; instruments for nitric oxide detection; sampling…

  6. News: Green Chemistry & Technology

    Science.gov (United States)

    A series of 21 articles focused on different features of green chemistry in a recent issue of Chemical Reviews. Topics extended over a wide range to include the design of sustainable synthetic processes to biocatalysis. A selection of perspectives follows as part of this colu

  7. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    For an excellent summary of the field of supramolecular chemistry, readers are referred to the article by J-M Lehn in Resonance, VaLl,. No.3, p.39, 1996. Electrostatics plays an important role in weak intermolecular interactions. The present series is aimed at understanding these electrostatic aspects. This article presents the.

  8. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Electrostatics in Chemistry. 3. Molecular Electrostatic Potential: Visualization and Topography. Shridhar R Gadre and Pravin K Bhadane. 1 1. Basic Principles, Resona- nce, Vol.4, No.2, 11-19, 1999. 2. Electrostatic Potentials of. Atoms, Ions and Molecules,. Resonance, Vol.4, No.5, 40-51,. 1999. Topographical features of the ...

  9. The Chemistry of Griseofulvin

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  10. Tunnelling Effects in Chemistry

    Indian Academy of Sciences (India)

    IAS Admin

    Tunnelling Effects in Chemistry. Molecules in the Strange Quantum World. Sharmistha Karmakar, Deepthi Jose and Ayan Datta. (left) Sharmistha Karmakar is doing her PhD in the group of. Ayan Datta, IACS,. Kolkata. Her research interests are modelling molecules with strong optical absorbtion and emission properties.

  11. Analytical Chemistry Laboratory

    Science.gov (United States)

    Anderson, Mark

    2013-01-01

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

  12. Forensic Chemistry Training

    Directory of Open Access Journals (Sweden)

    Zuhal GERÇEK

    2012-01-01

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

  13. Chemistry: The Middle Kingdom

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 7. Chemistry: The Middle Kingdom. Gautam R Desiraju. General Article Volume 12 Issue 7 July 2007 pp 44-60. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/012/07/0044-0060. Keywords.

  14. Symmetry in chemistry

    CERN Document Server

    Jaffé, Hans H

    1977-01-01

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

  15. Array processors in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, N.S.

    1980-01-01

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

  16. Teaching Chemistry. through Riddles

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 7. Teaching Chemistry through Riddles. Mala Das Sharma. Classroom Volume 9 Issue 7 July 2004 pp 74-76. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/07/0074-0076. Author Affiliations.

  17. Tunnelling Effects in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 2. Tunnelling Effects in Chemistry: Molecules in the Strange Quantum World. Sharmistha Karmakar Deepthi Jose Ayan Datta. General Article Volume 19 Issue 2 February 2014 pp 160-174 ...

  18. Chemistry in a Nutshell.

    Science.gov (United States)

    Rupnow, John; And Others

    1995-01-01

    Presents an activity that involves making peanut butter in the laboratory as a way to teach students the chemistry concepts of emulsification, solubility, and formulation. Enables students to realize that they can actually create or modify the physical and sensory characteristics of peanut butter and taste the differences in their work. (JRH)

  19. Nobel Prize in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 4. Nobel Prize in Chemistry – 2003 The Gateway for Perfect Health. S M Srideshikan S K Srivatsa. General Article Volume 9 Issue 4 April 2004 pp 61-70. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. Chemistry of Materials

    Indian Academy of Sciences (India)

    solid materials particularly metal oxides of various kinds. Then started intense activity in other classes of materials, including organics. It is no surprise that in the last few years, the two main streams of chemistry are directed towards biology and advanced materials. It is also not difficult to understand why chemists are getting ...

  1. Arrows in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 1. Arrows in Chemistry. Abirami Lakshminarayanan. General Article Volume 15 Issue 1 January 2010 pp 51-63. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/015/01/0051-0063. Keywords. Arrows ...

  2. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 2. Electrostatics in Chemistry - Basic Principles. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 2 February 1999 pp 8-19. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. Chemistry: The Middle Kingdom

    Indian Academy of Sciences (India)

    2005-02-10

    Feb 10, 2005 ... Chemistry occupies a unique middle position between physics and mathematics on the one side and biology, .... The late nineteenth century saw the zenith of the industrial revolution, the emergence of capitalism and colo- .... of the processes occurring in living systems. Chemists were slow to recognize the ...

  4. Supramolecular analytical chemistry.

    Science.gov (United States)

    Anslyn, Eric V

    2007-02-02

    A large fraction of the field of supramolecular chemistry has focused in previous decades upon the study and use of synthetic receptors as a means of mimicking natural receptors. Recently, the demand for synthetic receptors is rapidly increasing within the analytical sciences. These classes of receptors are finding uses in simple indicator chemistry, cellular imaging, and enantiomeric excess analysis, while also being involved in various truly practical assays of bodily fluids. Moreover, one of the most promising areas for the use of synthetic receptors is in the arena of differential sensing. Although many synthetic receptors have been shown to yield exquisite selectivities, in general, this class of receptor suffers from cross-reactivities. Yet, cross-reactivity is an attribute that is crucial to the success of differential sensing schemes. Therefore, both selective and nonselective synthetic receptors are finding uses in analytical applications. Hence, a field of chemistry that herein is entitled "Supramolecular Analytical Chemistry" is emerging, and is predicted to undergo increasingly rapid growth in the near future.

  5. Colour chemistry in water

    OpenAIRE

    Cardona, Maria

    2015-01-01

    Atmospheric carbon dioxide (CO2) levels have increased dramatically in the last few decades. Famous for causing global warming, CO2 is also resulting in the acidification of seas and oceans. http://www.um.edu.mt/think/colour-chemistry-in-water/

  6. Progression of Alzheimer Disease in Europe

    DEFF Research Database (Denmark)

    Vellas, B; Hausner, L; Frolich, L

    2012-01-01

    /first year, -2.5 pts/second year; ADAScog: + 3.5 pts/first year, + 4.8 pts/second year), while the progression of behavioral disturbances (NPI scale) was linear. Neither scale showed regional differences, and progression of the disease was similar across Europe despite different health care systems...

  7. African mistletoes (loranthaceae); ethnopharmacology, chemistry ...

    African Journals Online (AJOL)

    African mistletoes (loranthaceae); ethnopharmacology, chemistry and medicinal values: An update. ... little is known about their biology (taxonomy, host/plant relationship, ecology, toxicology, physiological characteristics, etc.) and chemistry (chemical constituents' profile). Some pharmacological studies carried out on the ...

  8. Polymer Chemistry in High School.

    Science.gov (United States)

    Stucki, Roger

    1984-01-01

    Discusses why polymer chemistry should be added to the general chemistry curriculum and what topics are appropriate (listing traditional with related polymer topics). Also discusses when and how these topics should be taught. (JN)

  9. Carbohydrate CuAAC click chemistry for therapy and diagnosis.

    Science.gov (United States)

    He, Xiao-Peng; Zeng, Ya-Li; Zang, Yi; Li, Jia; Field, Robert A; Chen, Guo-Rong

    2016-06-24

    Carbohydrates are important as signaling molecules and for cellular recognition events, therefore offering scope for the development of carbohydrate-mimetic diagnostics and drug candidates. As a consequence, the construction of carbohydrate-based bioactive compounds and sensors has become an active research area. While the advent of click chemistry has greatly accelerated the progress of medicinal chemistry and chemical biology, recent literature has seen an extensive use of such approaches to construct functionally diverse carbohydrate derivatives. Here we summarize some of the progress, covering the period 2010 to mid-2015, in Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition CuAAC "click chemistry" of carbohydrate derivatives, in the context of potential therapeutic and diagnostic tool development. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Mathematical problems for chemistry students

    CERN Document Server

    Pota, Gyorgy

    2011-01-01

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

  11. Eppur Si Muove! The 2013 Nobel Prize in Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jeremy C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Roux, Benoit [Univ. of Chicago, Chicago, IL (United States)

    2013-12-03

    The 2013 Nobel Prize in Chemistry has been awarded to Martin Karplus, Michael Levitt, and Arieh Warshel for their work on developing computational methods to study complex chemical systems. Hence, their work has led to mechanistic critical insights into chemical systems both large and small and has enabled progress in a number of different fields, including structural biology.

  12. Terpenoids of Sinularia soft corals: chemistry and bioactivity

    Directory of Open Access Journals (Sweden)

    Wen-ting Chen

    2012-06-01

    Full Text Available Soft corals of the genus Sinularia are one of the most widespread soft corals. They are a rich source of bioactive substances with intriguing and unique structural features. The present paper reviews the latest progress in the chemistry and pharmacological activities of terpenoids from Sinularia soft corals and provides a perspective on future areas of research interest.

  13. Experimental and Theoretical Studies of Atmosphereic Inorganic Chlorine Chemistry

    Science.gov (United States)

    Sander, Stanley P.; Friedl, Randall R.

    1993-01-01

    Over the last five years substantial progress has been made in defining the realm of new chlorine chemistry in the polar stratosphere. Application of existing experimental techniques to potentially important chlorine-containing compounds has yielded quantitative kinetic and spectroscopic data as well as qualitative mechanistic insights into the relevant reactions.

  14. Aqueous Solution Chemistry of Plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Clark, David L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-01-28

    Things I have learned working with plutonium: Chemistry of plutonium is complex; Redox equilibria make Pu solution chemistry particularly challenging in the absence of complexing ligands; Understanding this behavior is key to successful Pu chemistry experiments; There is no suitable chemical analog for plutonium.

  15. Six Pillars of Organic Chemistry

    Science.gov (United States)

    Mullins, Joseph J.

    2008-01-01

    This article describes an approach to teaching organic chemistry, which is to have students build their knowledge of organic chemistry upon a strong foundation of the fundamental concepts of the subject. Specifically, the article focuses upon a core set of concepts that I call "the six pillars of organic chemistry": electronegativity, polar…

  16. MINIATURIZING CHEMISTRY THE ECOLOGICAL ALTERNATIVE

    African Journals Online (AJOL)

    unesco

    Education in Chemistry (U.K.). • African Journal of Chemical Education (Ethiopia). • Educacion Quimica (Mexico). A list of books on the field is given in the appendix of this paper. WHERE DID IT START AND WHERE IS IT BEING USED? The adoption of Microscale Chemistry for the teaching of Chemistry in Africa and Asia is.

  17. Division of Analytical Chemistry, 1998

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    1999-01-01

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

  18. Scientific Information Analysis of Chemistry Dissertations Using Thesaurus of Chemistry

    Directory of Open Access Journals (Sweden)

    Taghi Rajabi

    2017-09-01

    Full Text Available : Concept maps of chemistry can be obtained from thesaurus of chemistry. Analysis of information in the field of chemistry is done at graduate level, based on comparing and analyzing chemistry dissertations by using these maps. Therefore, the use of thesaurus for analyzing scientific information is recommended. Major advantage of using this method, is that it is possible to obtain a detailed map of all academic researches across all branches of science. The researches analysis results in chemical science can play a key role in developing strategic research policies, educational programming, linking universities to industries and postgraduate educational programming. This paper will first introduce the concept maps of chemistry. Then, emerging patterns from the concept maps of chemistry will be used to analyze the trend in the academic dissertations in chemistry, using the data collected and stored in our database at Iranian Research Institute for Information Science and Technology (IranDoc over the past 10 years (1998-2009.

  19. How the Principles of Green Chemistry Changed the Way Organic Chemistry Labs Are Taught at the University of Detroit Mercy

    Science.gov (United States)

    Mio, Matthew J.

    2017-02-01

    Many logistic and instructional changes followed the incorporation of the 12 principles of green chemistry into organic chemistry laboratory courses at the University of Detroit Mercy. Over the last decade, institutional limitations have been turned into green chemical strengths in many areas, including integration of atom economy metrics into learning outcomes, replacing overly toxic equipment and reagents, and modifying matters of reaction scale and type.

  20. EDITORIAL: Ice in the environment: connections to atmospheric chemistry Ice in the environment: connections to atmospheric chemistry

    Science.gov (United States)

    McNeill, V. Faye; Hastings, Meredith G.

    2008-12-01

    understanding of the atmospheric chemistry of ice: the role of a quasi-liquid layer (QLL) or quasi-brine layer (QBL) at the ice surface. The studies presented here advance our understanding of the complex interactions of snow and ice with important reactive components in our atmosphere. It has become clear in recent years that the polar regions do not act as an ultimate sink for many compounds—the release of halogens and reactive nitrogen oxides from ice and snow are examples of this. Two notable implications arise from these findings (i) the impact of anthropogenic pollutants in our environment may extend further than we fully appreciate with current global atmospheric chemistry models and (ii) our interpretation of chemical records in ice cores requires that we fundamentally understand and quantify air-snow and air-ice interactions. Additionally, laboratory studies are elucidating the details of heterogeneous reactions that are prevalent on ice and snow surfaces throughout the troposphere, and we are poised to make significant strides in the near future quantifying these effects on regional and global scales. We look forward to continued progress in this field in the coming years, and we will continue to work to connect those conducting modeling, field and laboratory studies. Focus on Connections between Atmospheric Chemistry and Snow and Ice Contents HONO emissions from snow surfaces Harry Beine, Agustín J Colussi, Antonio Amoroso, Giulio Esposito, Mauro Montagnoli and Michael R Hoffmann Heterogeneous ozonation kinetics of phenanthrene at the air-ice interface T F Kahan and D J Donaldson Release of gas-phase halogens from sodium halide substrates: heterogeneous oxidation of frozen solutions and desiccated salts by hydroxyl radicals S J Sjostedt and J P D Abbatt Uptake of acetone, ethanol and benzene to snow and ice: effects of surface area and temperature J P D Abbatt, T Bartels-Rausch, M Ullerstam and T J Ye Interaction of gaseous elemental mercury with snow surfaces

  1. Physics and chemistry of irradiated protostars

    DEFF Research Database (Denmark)

    Lindberg, Johan

    not resemble so-called hot corinos or warm carbon-chain chemistry sources (the previously known types of low-mass Class 0 objects as defined by their chemistry). The absence of complex organic molecules in combination with high abundances of radicals such as cyanide (CN) and hydroxyl (OH) suggest...... that the chemistry is dominated by radiation from R CrA. In the high-resolution interferometry data we also detect signs of a 100 AU Keplerian disc around the Class 0/I object IRS7B. The disc may be responsible for the lack of detections of complex organic molecules on the smaller scales as it may have flattened......) and chemistry (such as molecular abundances) in low-mass protostellar envelopes is studied. The work studies the nearby low-mass star-forming region Corona Australis, in which a large proportion of the youngest low-mass protostars (so-called Class 0 and Class I objects) are located in a dense cloud situated...

  2. Towards "Bildung"-Oriented Chemistry Education

    Science.gov (United States)

    Sjöström, Jesper

    2013-01-01

    This paper concerns "Bildung"-oriented chemistry education, based on a reflective and critical discourse of chemistry. It is contrasted with the dominant type of chemistry education, based on the mainstream discourse of chemistry. "Bildung"-oriented chemistry education includes not only content knowledge in chemistry, but also…

  3. Chemistry of naphthalene diimides.

    Science.gov (United States)

    Bhosale, Sheshanath V; Jani, Chintan H; Langford, Steven J

    2008-02-01

    This tutorial review surveys recent developments in the chemistry of naphthalene diimides (NDIs) and explores their application in the fields of material and supramolecular science. It begins with a discussion of their general uses, methods of syntheses and their electronic and spectroscopic properties. Of interest to their application in the fields of conducting thin films and molecular sensors is the structure-function relationships that exist either as co-components of supramolecular ensembles as in the case of "nanotubes", or as the sole components in molecular wires. Also discussed are advances in NDI research within the areas of energy and electron transfer (covalent and non-covalent systems) and in host-guest chemistry including foldamer, mechanically-interlocked and ligand-gated ion channel examples. Finally, we explore the developments in the recent field of core-substituted NDIs, their photophysical properties and applications in artificial photosynthesis. We conclude with our views on the prospects of NDIs for future research endeavours.

  4. Organic Chemistry in Space

    Science.gov (United States)

    Charnley, Steven

    2009-01-01

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

  5. Chemistry and Art.

    Science.gov (United States)

    Lipscher, Juraj

    2018-02-01

    This review summarizes possibilities of including scientific methods for investigation of art objects into the secondary school chemistry curriculum. We discuss methods such as X-ray radiography, infrared reflectography, neutron activation autoradiography, X-ray fluorescence, and Raman spectroscopy and provide recent examples of their use. The results obtained, especially when combined with modern digital image processing algorithms, are indeed impressive. The second part of the paper is devoted to suggestions for actual use in teaching. The activities in the classroom can be centered around scientific investigation of a single painting, properties and use of a single pigment, or utilizing parallels in the history of Chemistry and history of Art. Finally, scientific methods for detecting art fraud including actual historical examples are especially motivating for the students and various teaching activities can be designed around this aspect.

  6. Chemistry space–time

    Directory of Open Access Journals (Sweden)

    David A. Winkler

    2015-12-01

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

  7. Bubble and foam chemistry

    CERN Document Server

    Pugh, Robert J

    2016-01-01

    This indispensable guide will equip the reader with a thorough understanding of the field of foaming chemistry. Assuming only basic theoretical background knowledge, the book provides a straightforward introduction to the principles and properties of foams and foaming surfactants. It discusses the key ideas that underpin why foaming occurs, how it can be avoided and how different degrees of antifoaming can be achieved, and covers the latest test methods, including laboratory and industrial developed techniques. Detailing a variety of different kinds of foams, from wet detergents and food foams, to polymeric, material and metal foams, it connects theory to real-world applications and recent developments in foam research. Combining academic and industrial viewpoints, this book is the definitive stand-alone resource for researchers, students and industrialists working on foam technology, colloidal systems in the field of chemical engineering, fluid mechanics, physical chemistry, and applied physics.

  8. 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.

  9. Quo vadis, analytical chemistry?

    Science.gov (United States)

    Valcárcel, Miguel

    2016-01-01

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

  10. Quantum mechanics in chemistry

    CERN Document Server

    Schatz, George C

    2002-01-01

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

  11. Green chemistry: development trajectory

    Science.gov (United States)

    Moiseev, I. I.

    2013-07-01

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

  12. Genetic algorithm in chemistry.

    OpenAIRE

    da Costa, PA; Poppi, RJ

    1999-01-01

    Genetic algorithm is an optimization technique based on Darwin evolution theory. In last years its application in chemistry is increasing significantly due the special characteristics for optimization of complex systems. The basic principles and some further modifications implemented to improve its performance are presented, as well as a historical development. A numerical example of a function optimization is also shown to demonstrate how the algorithm works in an optimization process. Final...

  13. Werner coordination chemistry and neurodegeneration.

    Science.gov (United States)

    Telpoukhovskaia, Maria A; Orvig, Chris

    2013-02-21

    Neurodegenerative diseases are capturing the world's attention as being the next set of diseases we must tackle collectively. Not only are the patients experiencing gradual cognitive and physical decline in most cases, but these diseases are fatal with no prevention currently available. As these diseases are progressive, providing care and symptom treatment for the ageing population is becoming both a medical and a financial challenge. This review discusses how Werner coordination chemistry plays a role in three diseases - those of Alzheimer's, Parkinson's, and prions. Metal ions are considered to be involved in these diseases in part via their propensity to cause toxic aggregation of proteins. First, the coordination of metal ions, with emphasis on copper(II), to metalloproteins that are hallmarks of these diseases - amyloid β, α-synuclein, and prion, respectively - will be discussed. We will present the current understanding of the metal coordination environments created by the amino acids of these proteins, as well as metal binding affinity. Second, a diverse set of examples of rationally designed metal chelators to outcompete this deleterious binding will be examined based on coordination mode and affinity toward bio-relevant metal ions. Overall, this review will give a general overview of protein and metal chelator coordination environments in neurodegenerative diseases.

  14. Chemistry of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  15. Minicomputer and computations in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The introduction of multiple-precision hardware and longer word lengths has given the minicomputer a much more general potential for chemistry applications. It was the purpose of this workshop to address this potential, particularly as it is related to computations. The workshop brought together persons with minicomputer experience and those who are considering how the minicomputer might enhance their research activities. The workshop sessions were arranged in sequence to address the following questions: (1) Is the general purpose minicomputer an appropriate tool to meet the computational requirements of a chemistry research laboratory. (2) What are the procedures for wisely designing a minicomputer configuration. (3) What special-purpose hardware is available to enhance the speed of a minicomputer. (4) How does one select the appropriate minicomputer and ensure that it can accomplish the tasks for which is was designed. (5) How can one network minicomputers for more efficient and flexible operation. (6) Can one do really large-scale computations on a minicomputer and what modifications are necessary to convert existing programs and algorithms. (7) How can the minicomputer be used to access the maxicomputers at the NRCC. (8) How are computers likely to evolve in the future. (9) What should be the role of the NRCC in relation to minicomputers. This report of the workshop consists mainly of edited transcripts of introductory remarks. These were augmented by relevant bibliographies as an alternative to transcription of the entire workshop. There was no attempt in the workshop to give final answers to the questions that were raised, since the answers are determined in large part by each particular minicomputer environment.

  16. Isotope and Nuclear Chemistry Division annual report FY 1986, October 1985-September 1986

    Energy Technology Data Exchange (ETDEWEB)

    Heiken, J.H. (ed.)

    1987-06-01

    This report describes progress in the major research and development programs carried out in FY 1986 by the Isotope and Nuclear Chemistry Division. The report includes articles on radiochemical diagnostics and weapons tests; weapons radiochemical diagnostics research and development; other unclassified weapons research; stable and radioactive isotope production and separation; chemical biology and nuclear medicine; element and isotope transport and fixation; actinide and transition metal chemistry; structural chemistry, spectroscopy, and applications; nuclear structure and reactions; irradiation facilities; advanced concepts and technology; and atmospheric chemistry.

  17. White Matter Lesion Progression in LADIS

    DEFF Research Database (Denmark)

    Schmidt, Reinhold; Berghold, Andrea; Jokinen, Hanna

    2012-01-01

    BACKGROUND AND PURPOSE: White matter lesion (WML) progression has been advocated as a surrogate marker in intervention trials on cerebral small vessel disease. We assessed the rate of visually rated WML progression, studied correlations between lesion progression and cognition, and estimated sample...... grade on the Rotterdam Progression Scale. RESULTS: WML progression related to deterioration in cognitive functioning. This relationship was less pronounced in subjects with early confluent and confluent lesions. Consequently, studies in which the outcome is cognitive change resulting from treatment...... effects on lesion progression will need between 1809 subjects per treatment arm when using executive tests and up to 18 853 subjects when using the Vascular Dementia Assessment Scale score. Studies having WML progression as the sole outcome will need only 58 or 70 individuals per treatment arm...

  18. Spotlight on medicinal chemistry education.

    Science.gov (United States)

    Pitman, Simone; Xu, Yao-Zhong; Taylor, Peter; Turner, Nicholas; Coaker, Hannah; Crews, Kasumi

    2014-05-01

    The field of medicinal chemistry is constantly evolving and it is important for medicinal chemists to develop the skills and knowledge required to succeed and contribute to the advancement of the field. Future Medicinal Chemistry spoke with Simone Pitman (SP), Yao-Zhong Xu (YX), Peter Taylor (PT) and Nick Turner (NT) from The Open University (OU), which offers an MSc in Medicinal Chemistry. In the interview, they discuss the MSc course content, online teaching, the future of medicinal chemistry education and The OU's work towards promoting widening participation. SP is a Qualifications Manager in the Science Faculty at The OU. She joined The OU in 1993 and since 1998 has been involved in the Postgraduate Medicinal Chemistry provision at The OU. YX is a Senior Lecturer in Bioorganic Chemistry at The OU. He has been with The OU from 2001, teaching undergraduate courses of all years and chairing the master's course on medicinal chemistry. PT is a Professor of Organic Chemistry at The OU and has been involved with the production and presentation of The OU courses in Science and across the university for over 30 years, including medicinal chemistry modules at postgraduate level. NT is a Lecturer in Analytical Science at The OU since 2009 and has been involved in the production of analytical sciences courses, as well as contributing to the presentation of a number of science courses including medicinal chemistry.

  19. Delivering a Chemistry Course over the Internet

    Science.gov (United States)

    Brooks, David W.; Liu, Daonian; Walter, L. James

    1998-01-01

    A tuition-based course in small scale chemistry activities for high school laboratories aimed at high school chemistry teachers was offered over the Internet during the spring semester, 1995. A CD-ROM with descriptions of activities and movies served as the text for the course. The content was divided into seven modules. While most of the students responded well to the course, only half completed the course for a grade. Communications during the course were maintained using email and a listserv. All of the electronic communications and interviews with the instructor and over half of the students served as the basis for a qualitative research study. The various positive and negative factors related to teaching and taking a course in this format are described.

  20. Predicting progression in primary progressive multiple sclerosis: a 10-year multicenter study

    NARCIS (Netherlands)

    Khaleeli, Z.; Ciccarelli, O.; Manfredonia, F.; Barkhof, F.; Brochet, B.; Cercignani, M.; Dousset, V.; Filippi, M.; Montalban, X.; Polman, C.H.; Rovaris, M.; Rovira, A.; Sastre-Garriga, J.; Vellinga, M.M.; Miller, D.; Thompson, A.

    2008-01-01

    Rates of progression vary widely in primary progressive multiple sclerosis. This multicenter study aimed to identify predictors of progression over 10 years. A total of 101 patients who had been imaged at baseline and 2 years were scored on the expanded disability status scale after 10 years.

  1. Comparison of multiple atmospheric chemistry schemes in C-IFS

    Science.gov (United States)

    Flemming, Johannes; Huijnen, Vincent; Arteta, Joaquim; Stein, Olaf; Inness, Antje; Josse, Beatrice; Schultz, Martin; Peuch, Vincent-Henri

    2013-04-01

    As part of the MACCII -project (EU-FP7) ECMWF's integrated forecast system (IFS) is being extended by modules for chemistry, deposition and emission of reactive gases. This integration of the chemistry complements the integration of aerosol processes in IFS (Composition-IFS). C-IFS provides global forecasts and analysis of atmospheric composition. Its main motivation is to utilize the IFS for the assimilation of satellite observation of atmospheric composition. Furthermore, the integration of chemistry packages directly into IFS will achieve better consistency in terms of the treatment of physical processes and has the potential for simulating interactions between atmospheric composition and meteorology. Atmospheric chemistry in C-IFS can be represented by the modified CB05 scheme as implemented in the TM5 model and the RACMOBUS scheme as implemented in the MOCAGE model. An implementation of the scheme of the MOZART 3.5 model is ongoing. We will present the latest progress in the development and application of C-IFS. We will focus on the comparison of the different chemistry schemes in an otherwise identical C-IFS model setup (emissions, meteorology) as well as in their original Chemistry and Transport Model setup.

  2. Green Chemistry at the present in Korea.

    Science.gov (United States)

    Lee, Seung-Kyu; Park, Hyeon-Soo

    2015-01-01

    Despite the great contribution made by chemical substances to the development of modern civilization, their indiscriminate use has caused various kinds of damage to the global environment and human beings. Accordingly, the major developed countries and international society have tried to ensure the safe use of chemicals and a reduction in the use of hazardous chemicals through the establishment of the United Nations Environment Programme and various international agreements. In this reason, we tried to introduce about Green Chemistry progress at the present in worldwide and Korea. We checked and analyzed relative journals, reports using keyword as like Green Chemistry, alternative chemicals, eco-friendly etc. and major country's government homepage search. Green Chemistry theory, which argues for the reduction or removal of harmfulness in chemicals throughout their entire life-cycle, has been spreading, and major developed countries, such as the US and Denmark, have developed and operate programs to provide reliable chemical information to help replace hazardous chemicals. Korea has also been conducting studies as like eco-innovation project. Through this project the "Alternative Chemical Search program," has been developed, distributed, and operated since 2011 to provide reliable information to small and medium-sized businesses that have difficulties collecting information to ensure conformity to international regulations. The program provides information that includes the regulations of major countries and Korea, information on 340 alternative chemicals, 70 application cases, and 1:1 consulting. The Alternative Chemical Search program is expected to contribute to the establishment of response systems for regulation of Korean small and medium-sized businesses, and it also will be used to provide basic data for Korean hazardous chemical regulation, together with the Act on the Registration and Evaluation, etc. of Chemical Substances and the Chemical Control act

  3. EDITORIAL: Catalysing progress Catalysing progress

    Science.gov (United States)

    Demming, Anna

    2010-01-01

    Examples of the merits of blue-sky research in the history of science are legion. The invention of the laser, celebrating its 50th anniversary this year, is an excellent example. When it was invented it was considered to be 'a solution waiting for a problem', and yet the level to which it has now infiltrated our day-to-day technological landscape speaks volumes. At the same time it is also true to say that the direction of research is also at times rightly influenced by the needs and concerns of the general public. Over recent years, growing concerns about the environment have had a noticeable effect on research in nanotechnology, motivating work on a range of topics from green nanomaterial synthesis [1] to high-efficiency solar cells [2] and hydrogen storage [3]. The impact of the world's energy consumption on the welfare of the planet is now an enduring and well founded concern. In the face of an instinctive reluctance to curtail habits of comfort and convenience and the appendages of culture and consumerism, research into renewable and more efficient energy sources seem an encouraging approach to alleviating an impending energy crisis. Fuel cells present one alternative to traditional combustion cells that have huge benefits in terms of the efficiency of energy conversion and the limited harmful emissions. In last week's issue of Nanotechnology, Chuan-Jian Zhong and colleagues at the State University of New York at Binghamton in the USA presented an overview of research on nanostructured catalysts in fuel cells [4]. The topical review includes insights into the interactions between nanoparticles and between nanoparticles and their substrate as well as control over the composition and nanostructure of catalysts. The review also serves to highlight how the flourishing of nanotechnology research has heralded great progress in the exploitation of catalysts with nanostructures ingeniously controlled to maximize surface area and optimize energetics for synthesis

  4. Perception of the Relevance of Organic Chemistry in a German Pharmacy Students' Course.

    Science.gov (United States)

    Wehle, Sarah; Decker, Michael

    2016-04-25

    Objective. To investigate German pharmacy students' attitudes toward the relevance of organic chemistry training in Julius Maximilian University (JMU) of Würzburg with regard to subsequent courses in the curricula and in later prospective career options. Methods. Surveys were conducted in the second-year organic chemistry course (50 participants) as well as during the third-year and fourth-year lecture cycle on medicinal and pharmaceutical chemistry (66 participants) in 2014. Results. Students' attitudes were surprisingly consistent throughout the progress of the degree course. Students considered organic chemistry very relevant to the pharmacy study program (95% junior and 97% senior students), and of importance for their future pharmacy program (88% junior and 94% senior students). With regard to prospective career options, the perceived relevance was considerably lower and attitudes were less homogenous. Conclusions. German pharmacy students at JMU Würzburg consider organic chemistry of high relevance for medicinal chemistry and other courses in JMU's pharmacy program.

  5. Physical chemistry II essentials

    CERN Document Server

    REA, The Editors of

    1992-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Physical Chemistry II includes reaction mechanisms, theoretical approaches to chemical kinetics, gravitational work, electrical and magnetic work, surface work, kinetic theory, collisional and transport properties of gases, statistical mechanics, matter and waves, quantum mechanics, and rotations and vibrations of atoms and molecules.

  6. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  7. Chemistry and Science Fiction

    Science.gov (United States)

    Stocker, Jack H.

    1998-11-01

    This lively collection looks at science as filtered through literature, film, and television. It discusses classic works in science fiction and provides an in-depth look at the chemistry depicted in popular culture, particularly in Start Trek , Star Wars , and Doctor Who . It includes an examination by Nebula Award winner Connie Willis of how science fiction authors use science, and reprints two tongue-in-cheek short stories by Isaac Asimov. The book also includes suggestions for using science fiction as an educational resource.

  8. Chemistry in space

    CERN Document Server

    Rehder, Dieter

    2010-01-01

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

  9. 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.

  10. 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

  11. Radiochemistry and nuclear chemistry

    CERN Document Server

    Choppin, Gregory; RYDBERG, JAN; Ekberg, Christian

    2013-01-01

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

  12. Quantum chemistry an introduction

    CERN Document Server

    Kauzmann, Walter

    2013-01-01

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

  13. Nuclear Chemistry and Services

    Energy Technology Data Exchange (ETDEWEB)

    Vandevelde, L

    2002-04-01

    The objectives, the programme, and the achievements of R and D at the Belgian Nuclear Research Centre SCK-CEN in the field of nuclear chemistry and analytical techniques are summarized. Major achievement in 2001 included the completion of a project on the measurement of critical radionuclides in reactor waste fluxes (the ARIANE project), the radiochemical characterisation of beryllium material originating from the second matrix of the BR2 reactor as well as to a the organisation of a workshop on the analysis of thorium and its isotopes in workplace materials.

  14. Analytical chemistry in space

    CERN Document Server

    Wainerdi, Richard E

    1970-01-01

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

  15. Progress in molecular precursors for electronic materials

    Energy Technology Data Exchange (ETDEWEB)

    Buhro, W.E. [Washington Univ., St. Louis, MO (United States)

    1996-09-01

    Molecular-precursor chemistry provides an essential underpinning to all electronic-materials technologies, including photovoltaics and related areas of direct interest to the DOE. Materials synthesis and processing is a rapidly developing field in which advances in molecular precursors are playing a major role. This article surveys selected recent research examples that define the exciting current directions in molecular-precursor science. These directions include growth of increasingly complex structures and stoichiometries, surface-selective growth, kinetic growth of metastable materials, growth of size-controlled quantum dots and quantum-dot arrays, and growth at progressively lower temperatures. Continued progress in molecular-precursor chemistry will afford precise control over the crystal structures, nanostructures, and microstructures of electronic materials.

  16. Exploiting Locality in Quantum Computation for Quantum Chemistry.

    Science.gov (United States)

    McClean, Jarrod R; Babbush, Ryan; Love, Peter J; Aspuru-Guzik, Alán

    2014-12-18

    Accurate prediction of chemical and material properties from first-principles quantum chemistry is a challenging task on traditional computers. Recent developments in quantum computation offer a route toward highly accurate solutions with polynomial cost; however, this solution still carries a large overhead. In this Perspective, we aim to bring together known results about the locality of physical interactions from quantum chemistry with ideas from quantum computation. We show that the utilization of spatial locality combined with the Bravyi-Kitaev transformation offers an improvement in the scaling of known quantum algorithms for quantum chemistry and provides numerical examples to help illustrate this point. We combine these developments to improve the outlook for the future of quantum chemistry on quantum computers.

  17. NUCLEAR CHEMISTRY ANNUAL REPORT 1970

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1971-05-01

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

  18. Research needs and opportunities in radiation chemistry workshop

    Energy Technology Data Exchange (ETDEWEB)

    Barbara, Paul F

    1998-04-19

    There is a growing urgency for forefront basic research on ionizing radiation-induced chemical reactions, due to the relevance of these reactions in such areas of critical national need as environmental waste management, environmental remediation, nuclear energy production, and medical diagnosis and radiation therapy. Fortunately, the emergence of new theoretical and experimental tools for the study of radiation-induced chemical and physical processes, i.e. Radiation Chemistry, makes future progress quite promising. Nevertheless, a recent decline in he number of young investigators in radiation chemistry, as well as a natural obsolescence of large research facilities in radiation chemistry are serious obstacles to further progress. Understanding radiation-induced processes is of vital significance in such diverse fields as waste remediation in environmental cleanup, radiation processing of polymers and food, medical diagnosis and therapy, catalysis of chemical reactions, environmentally benign synthesis, and nuclear energy production. Radiation chemistry provides for these fields fundamental quantitative data, such as reaction rate coefficients, diffusion coefficients, radiation chemical yields, etc. As well as providing useful quantitative information of technological and medical importance, radiation chemistry is also a valuable tool for solving fundamental problems in chemistry and in material sciences. Exploiting the many facets of radiation chemistry requires a thorough and comprehensive understanding of the underlying chemical and physical processes. An understanding of the structure and dynamics of “tracks” produced by ionizing radiation is a central issue in the field. There is a continuing need to study the ultrafast processes that link the chemistry and physics of radiation-induced phenomena. This is especially true for practically important, but less well understood, nonstandard environments such as interfacial systems, supercritical media, and

  19. The physical basis of chemistry

    CERN Document Server

    Warren, Warren S

    2000-01-01

    If the text you're using for general chemistry seems to lack sufficient mathematics and physics in its presentation of classical mechanics, molecular structure, and statistics, this complementary science series title may be just what you're looking for. Written for the advanced lower-division undergraduate chemistry course, The Physical Basis of Chemistry, Second Edition, offers students an opportunity to understand and enrich the understanding of physical chemistry with some quantum mechanics, the Boltzmann distribution, and spectroscopy. Posed and answered are questions concerning eve

  20. Podcasts in the Chemistry Teaching

    Directory of Open Access Journals (Sweden)

    Bruno Silva Leite

    2016-12-01

    Full Text Available Information and Communication Technologies (ICT provide facilities in teaching through education. There are many new tools and methodologies that use ICT as a knowledge-building support, but that are not always related to pedagogical practice. The Podcast is an important technology that can be used in the classroom. Using this tool, it can make the most interactive chemistry class, fleeing the classroom routine. However, it is necessary to point out that the podcast is just one feature that should be incorporated into education and not a substitute. This paper describes the development of Chemistry Podcasts by teachers and chemistry students in three disciplines in 2015. This study took place over a one-year period in a public University, in Pernambuco, Brazil. In the discipline of "Computer applied to the teaching of chemistry" participated 21 Chemistry teachers. In the disciplines of "Information and Communication Technologies in the teaching of chemistry" and "Informatics, Chemistry and Education" was composed of 54 undergraduate students in chemistry. Twelve podcasts were elaborated by students and five by teachers in this paper we present only nine. The results showed the contribution of podcasts produced by teachers and students in teaching and learning process chemistry. DOI: http://dx.doi.org/10.17807/orbital.v0i0.898

  1. Green Chemistry for Chemical Synthesis

    National Research Council Canada - National Science Library

    Chao-Jun Li; Barry M. Trost

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize...

  2. Information theory in analytical chemistry

    National Research Council Canada - National Science Library

    Eckschlager, Karel; Danzer, Klaus

    1994-01-01

    Contents: The aim of analytical chemistry - Basic concepts of information theory - Identification of components - Qualitative analysis - Quantitative analysis - Multicomponent analysis - Optimum analytical...

  3. Solid state chemistry an introduction

    CERN Document Server

    Smart, Lesley E

    2012-01-01

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

  4. Progress in surface and membrane science

    CERN Document Server

    Danielli, J F; Cadenhead, D A

    1973-01-01

    Progress in Surface and Membrane Science, Volume 6 covers the developments in the study of surface and membrane science. The book discusses the progress in surface and membrane science; the solid state chemistry of the silver halide surface; and the experimental and theoretical aspects of the double layer at the mercury-solution interface. The text also describes contact-angle hysteresis; ion binding and ion transport produced by neutral lipid-soluble molecules; and the biophysical interactions of blood proteins with polymeric and artificial surfaces. Physical chemists, biophysicists, and phys

  5. Organometallic Neptunium Chemistry.

    Science.gov (United States)

    Arnold, Polly L; Dutkiewicz, Michał S; Walter, Olaf

    2017-09-13

    Fifty years have passed since the foundation of organometallic neptunium chemistry, and yet only a handful of complexes have been reported, and even fewer have been fully characterized. Yet, increasingly, combined synthetic/spectroscopic/computational studies are demonstrating how covalently bonding, soft, carbocyclic organometallic ligands provide an excellent platform for advancing the fundamental understanding of the differences in orbital contributions and covalency in f-block metal-ligand bonding. Understanding the subtleties is the key to the safe handling and separations of the highly radioactive nuclei. This review describes the complexes that have been synthesized to date and presents a critical assessment of the successes and difficulties in their analysis and the bonding information they have provided. Because of increasing recent efforts to start new Np-capable air-sensitive inorganic chemistry laboratories, the importance of radioactivity, the basics of Np decay and its ramifications (including the radiochemical synthesis of one organometallic compound), and the available anhydrous starting materials are also surveyed. The review also highlights a range of instances in which important differences in the chemical behavior between Np and its closest neighbors, uranium and plutonium, are found.

  6. Moving beyond feasibility in ultrafast shock chemistry experiments

    Science.gov (United States)

    Armstrong, Michael; Lewicki, James; Crowhurst, Jonathan; Zaug, Joseph; Radousky, Harry; Stavrou, Elissaios; Sawvel, April

    Although ultrafast hydrodynamic methods to investigate the chemistry of shocked materials on ps to ns time scales are generally mature, questions about the interpretation of such experiments remain. Most ultrafast experiments employ shock etalon methods whose interpretation depends on assumptions about the index of refraction of the shocked state. Further, although signatures for chemistry in longer time scale time-of-flight (ToF) experiments are well understood, ultrafast chemistry experiments have not typically employed ToF methods. The use of ToF methods in ultrafast experiments would enable a more straightforward connection to longer time scale data, and would generally provide more information than shock etalon methods. Finally, ultrafast experiments have not been performed over time scales greater than a few hundred of picoseconds, significantly limiting the scope of experiments to observe shocked chemistry under typical conditions at larger length scales. Here we address all of these issues by presenting data from shocked polymers obtained using both ToF and shock etalon methods, using a 1 ns pump and observation window. We compare the results of these two methods to reconcile data from these different methods and strengthen the interpretation of both types of experiment. Prepared by LLNL under Contract DE-AC52-07NA27344.

  7. Embedded Mathematics in Chemistry: A Case Study of Students' Attitudes and Mastery

    Science.gov (United States)

    Preininger, Anita M.

    2017-02-01

    There are many factors that shape students' attitudes toward science, technology, engineering and mathematics. This exploratory study of high school students examined the effect of enriching chemistry with math on chemistry students' attitudes toward math and careers involving math. To measure student attitudes, a survey was administered before and after the 18-week chemistry class; results from the chemistry class were compared to survey results from students in an elective science class that did not emphasize mathematics. At the end of the 18-week period, only the chemistry students exhibited more positive views toward their abilities in mathematics and careers that involve mathematics, as compared to their views at the outset of the course. To ensure that chemistry mastery was not hindered by the additional emphasis on math, and that mastery on state end-of-course examinations reflected knowledge acquired during the math-intensive chemistry class, a chemistry progress test was administered at the start and end of the term. This exploratory study suggests that emphasizing mathematical approaches in chemistry may positively influence attitudes toward math in general, as well as foster mastery of chemistry content.

  8. Chemistry in Context: Analysis of Thematic Chemistry Videos Available Online

    Science.gov (United States)

    Christensson, Camilla; Sjöström, Jesper

    2014-01-01

    United Nations declared 2011 to be the International Year of Chemistry. The Swedish Chemical Society chose twelve themes, one for each month, to highlight the connection of chemistry with everyday life. Examples of themes were fashion, climate change, love, sports, communication, health issues, and food. From the themes various context-based…

  9. A Quantum Chemistry Concept Inventory for Physical Chemistry Classes

    Science.gov (United States)

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

    2016-01-01

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

  10. Chemistry for Whom? Gender Awareness in Teaching and Learning Chemistry

    Science.gov (United States)

    Andersson, Kristina

    2017-01-01

    Marie Ståhl and Anita Hussénius have defined what discourses dominate national tests in chemistry for Grade 9 in Sweden by using feminist, critical didactic perspectives. This response seeks to expand the results in Ståhl and Hussénius's article "Chemistry inside an epistemological community box!--Discursive exclusions and inclusions in the…

  11. Nuclear Chemistry and Chemistry of f-Elements in Chemistry Curriculum at Secondary Schools

    OpenAIRE

    Distler, Petr

    2016-01-01

    This master's degree thesis, called Nuclear Chemistry and Chemistry of f-Elements in Chemistry Curriculum at Secondary Schools, conducts a research of the most commonly used high school textbooks. Within the textbook research, topics such as atomic nucleus composition, radioactivity, and f-elements were studied in order to evaluate to what extent contemporary textbooks meet to the curriculum requirements. Based on the textbook research, the new teaching texts, materials, and teaching tasks in...

  12. Fundamental quantitative analysis of microbial activity in aquifer bioreclamation; and Modeling the transport of biologically and chemically reactive solutes in a two-dimensional, heterogeneous intermediate scale system. Semi-annual progress report, August 1991--March 1992

    Energy Technology Data Exchange (ETDEWEB)

    Rittmann, B.E.; Valocchi, A.J. [Illinois Univ., Urbana, IL (United States). Dept. of Civil Engineering; Baveye, P. [Cornell Univ., Ithaca, NY (United States). Dept. of Agronomy

    1992-12-31

    This report is the semi-annual progress report for the second half of the third year. The project has four primary areas: (1) biodegradation of poorly soluble organic contaminants; (2) dual-limitation kinetics of electron donors and acceptors; (3) two-dimensional modeling of biofilm reactions in nonhomogeneous porous media; and (4) biologically induced clogging in porous media. For each area, this report presents a brief summary of the previous progress, as well as reporting this period`s progress. In addition plans for future work are included.

  13. From organic chemistry to fat and oil chemistry*

    Directory of Open Access Journals (Sweden)

    Deffense Etienne

    2009-01-01

    Full Text Available With his work on animal fat and identification of fatty acids, Chevreul was a pioneer in organic chemistry. As Chevreul, I had a passion for organic chemistry too. It was then, an honour and a pleasure to present in 2008 at EFL in Athens this presentation entitled “From organic chemistry to fat and oil chemistry” because my background in organic chemistry helped me all along my professional career to understand and implement new developments related to oil and fat technology and processing. Among the topics which I worked out, I highlighted more particularly the following subjects: the degumming chemistry of oil and fat; the improvement of physical refining; a new chemical analytical tool for the dry fractionation; new development in the dry fractionation

  14. Global atmospheric chemistry - which air matters

    Science.gov (United States)

    Prather, Michael J.; Zhu, Xin; Flynn, Clare M.; Strode, Sarah A.; Rodriguez, Jose M.; Steenrod, Stephen D.; Liu, Junhua; Lamarque, Jean-Francois; Fiore, Arlene M.; Horowitz, Larry W.; Mao, Jingqiu; Murray, Lee T.; Shindell, Drew T.; Wofsy, Steven C.

    2017-07-01

    An approach for analysis and modeling of global atmospheric chemistry is developed for application to measurements that provide a tropospheric climatology of those heterogeneously distributed, reactive species that control the loss of methane and the production and loss of ozone. We identify key species (e.g., O3, NOx, HNO3, HNO4, C2H3NO5, H2O, HOOH, CH3OOH, HCHO, CO, CH4, C2H6, acetaldehyde, acetone) and presume that they can be measured simultaneously in air parcels on the scale of a few km horizontally and a few tenths of a km vertically. As a first step, six global models have prepared such climatologies sampled at the modeled resolution for August with emphasis on the vast central Pacific Ocean basin. Objectives of this paper are to identify and characterize differences in model-generated reactivities as well as species covariances that could readily be discriminated with an unbiased climatology. A primary tool is comparison of multidimensional probability densities of key species weighted by the mass of such parcels or frequency of occurrence as well as by the reactivity of the parcels with respect to methane and ozone. The reactivity-weighted probabilities tell us which parcels matter in this case, and this method shows skill in differentiating among the models' chemistry. Testing 100 km scale models with 2 km measurements using these tools also addresses a core question about model resolution and whether fine-scale atmospheric structures matter to the overall ozone and methane budget. A new method enabling these six global chemistry-climate models to ingest an externally sourced climatology and then compute air parcel reactivity is demonstrated. Such an objective climatology containing these key species is anticipated from the NASA Atmospheric Tomography (ATom) aircraft mission (2015-2020), executing profiles over the Pacific and Atlantic Ocean basins. This modeling study addresses a core part of the design of ATom.

  15. Tropospheric Halogen Chemistry

    Science.gov (United States)

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

    2003-12-01

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

  16. Quarterly Progress Report (April 1 to June 30, 1950)

    Energy Technology Data Exchange (ETDEWEB)

    Brookhaven National Laboratory

    1950-07-01

    This is the second of a series of Quarterly Progress Reports. While most of the departments have summarized their work or used a form comparable to abstracts, the Chemistry Department has given both abstracts and complete reports on its work. The major part of the progress in the Reactor Science and Engineering Department is being presented simultaneously in a separate classified report. There are reports from the following departments: (1) physics department; (2) instrumentation and health physics department; (3) accelerator project; (4) chemistry department; (5) reactor science and engineering department; (6) biology department; and (7) medical department.

  17. Dynamic imine chemistry.

    Science.gov (United States)

    Belowich, Matthew E; Stoddart, J Fraser

    2012-03-21

    Formation of an imine--from an amine and an aldehyde--is a reversible reaction which operates under thermodynamic control such that the formation of kinetically competitive intermediates are, in the fullness of time, replaced by the thermodynamically most stable product(s). For this fundamental reason, the imine bond has emerged as an extraordinarily diverse and useful one in the hands of synthetic chemists. Imine bond formation is one of a handful of reactions which define a discipline known as dynamic covalent chemistry (DCC), which is now employed widely in the construction of exotic molecules and extended structures on account of the inherent 'proof-reading' and 'error-checking' associated with these reversible reactions. While both supramolecular chemistry and DCC operate under the regime of reversibility, DCC has the added advantage of constructing robust molecules on account of the formation of covalent bonds rather than fragile supermolecules resulting from noncovalent bonding interactions. On the other hand, these products tend to require more time to form--sometimes days or even months--but their formation can often be catalysed. In this manner, highly symmetrical molecules and extended structures can be prepared from relatively simple precursors. When DCC is utilised in conjunction with template-directed protocols--which rely on the use of noncovalent bonding interactions between molecular building blocks in order to preorganise them into certain relative geometries as a prelude to the formation of covalent bonds under equilibrium control--an additional level of control of structure and topology arises which offers a disarmingly simple way of constructing mechanically-interlocked molecules, such as rotaxanes, catenanes, Borromean rings, and Solomon knots. This tutorial review focuses on the use of dynamic imine bonds in the construction of compounds and products formed with and without the aid of additional templates. While synthesis under thermodynamic

  18. Compressed Sensing for Chemistry

    Science.gov (United States)

    Sanders, Jacob Nathan

    Many chemical applications, from spectroscopy to quantum chemistry, involve measuring or computing a large amount of data, and then compressing this data to retain the most chemically-relevant information. In contrast, compressed sensing is an emergent technique that makes it possible to measure or compute an amount of data that is roughly proportional to its information content. In particular, compressed sensing enables the recovery of a sparse quantity of information from significantly undersampled data by solving an ℓ 1-optimization problem. This thesis represents the application of compressed sensing to problems in chemistry. The first half of this thesis is about spectroscopy. Compressed sensing is used to accelerate the computation of vibrational and electronic spectra from real-time time-dependent density functional theory simulations. Using compressed sensing as a drop-in replacement for the discrete Fourier transform, well-resolved frequency spectra are obtained at one-fifth the typical simulation time and computational cost. The technique is generalized to multiple dimensions and applied to two-dimensional absorption spectroscopy using experimental data collected on atomic rubidium vapor. Finally, a related technique known as super-resolution is applied to open quantum systems to obtain realistic models of a protein environment, in the form of atomistic spectral densities, at lower computational cost. The second half of this thesis deals with matrices in quantum chemistry. It presents a new use of compressed sensing for more efficient matrix recovery whenever the calculation of individual matrix elements is the computational bottleneck. The technique is applied to the computation of the second-derivative Hessian matrices in electronic structure calculations to obtain the vibrational modes and frequencies of molecules. When applied to anthracene, this technique results in a threefold speed-up, with greater speed-ups possible for larger molecules. The

  19. Stochasticity in processes fundamentals and applications to chemistry and biology

    CERN Document Server

    Schuster, Peter

    2016-01-01

    This book has developed over the past fifteen years from a modern course on stochastic chemical kinetics for graduate students in physics, chemistry and biology. The first part presents a systematic collection of the mathematical background material needed to understand probability, statistics, and stochastic processes as a prerequisite for the increasingly challenging practical applications in chemistry and the life sciences examined in the second part. Recent advances in the development of new techniques and in the resolution of conventional experiments at nano-scales have been tremendous: today molecular spectroscopy can provide insights into processes down to scales at which current theories at the interface of physics, chemistry and the life sciences cannot be successful without a firm grasp of randomness and its sources. Routinely measured data is now sufficiently accurate to allow the direct recording of fluctuations. As a result, the sampling of data and the modeling of relevant processes are doomed t...

  20. PVUSA progress report, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Ellyn, W. [ed.] [Nesbit (William) and Associates, Santa Rosa, CA (United States); Jennings, C. [ed.] [Pacific Gas and Electric Co., San Ramon, CA (United States)

    1991-12-31

    Photovoltaics for Utility Scale Applications (PVUSA) is a national public-private partnership that is assessing and demonstrating the viability of utility-scale photovoltaic (PV) electric generating systems. PVUSA participants include Pacific Gas & Electric (PG&E), the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), the California Energy Commission (CEC), and eight utilities and other agencies. This report updates the progress of the PVUSA project, reviews the status and performance of the various PV installations during 1991, and summarizes key findings and conclusions from work to date. PVUSA offers utilities hands-on experience needed to evaluate and utilize maturing PV technology. The project also provides manufacturers a test bed for their products, encourages technology improvement and cost reductions in PV modules and other system components, and establishes communication channels between utilities and the PV industry. The project consists of two types of demonstrations: Emerging Module Technology (EMT) arrays, which are unproven but promising state-of-the-art PV technologies in 20-kW (nominal) arrays; and Utility Scale (US) systems, which represent more mature PV technologies in 200- to 500-kW turnkey systems.

  1. The impact of Future Land Use and Land Cover Changes on Atmospheric Chemistry-Climate Interactions

    NARCIS (Netherlands)

    Ganzeveld, L.N.; Bouwman, L.

    2010-01-01

    To demonstrate potential future consequences of land cover and land use changes beyond those for physical climate and the carbon cycle, we present an analysis of large-scale impacts of land cover and land use changes on atmospheric chemistry using the chemistry-climate model EMAC (ECHAM5/MESSy

  2. The Interaction Effects of Gender and Grade Level on Secondary School Students' Attitude towards Learning Chemistry

    Science.gov (United States)

    Heng, Chua Kah; Karpudewan, Mageswary

    2015-01-01

    This quantitative study reports the effects of gender and grade level on secondary students' attitude towards chemistry lessons. For this purpose, the Attitude towards Chemistry Lessons Scale (ATCLS) was administered to 446 secondary school students between 16-19 years old. The ATCLS consists of four different subscales: liking for chemistry…

  3. Degradation of Environmental Contaminants with Water-Soluble Cobalt Catalysts: An Integrative Inorganic Chemistry Investigation

    Science.gov (United States)

    Evans, Alexandra L.; Messersmith, Reid E.; Green, David B.; Fritsch, Joseph M.

    2011-01-01

    We present an integrative laboratory investigation incorporating skills from inorganic chemistry, analytical instrumentation, and physical chemistry applied to a laboratory-scale model of the environmental problem of chlorinated ethylenes in groundwater. Perchloroethylene (C[subscript 2]Cl[subscript 4], PCE) a common dry cleaning solvent,…

  4. Chemical Transfer (Single Small-Scale) Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Description/History: Chemistry laboratoryThe Chemical Transfer Facility (CTF)  is the only U.S. single small-scale  facility, a single repository for the Army’s...

  5. Introductory lecture: atmospheric chemistry in the Anthropocene.

    Science.gov (United States)

    Finlayson-Pitts, Barbara J

    2017-08-24

    The term "Anthropocene" was coined by Professor Paul Crutzen in 2000 to describe an unprecedented era in which anthropogenic activities are impacting planet Earth on a global scale. Greatly increased emissions into the atmosphere, reflecting the advent of the Industrial Revolution, have caused significant changes in both the lower and upper atmosphere. Atmospheric reactions of the anthropogenic emissions and of those with biogenic compounds have significant impacts on human health, visibility, climate and weather. Two activities that have had particularly large impacts on the troposphere are fossil fuel combustion and agriculture, both associated with a burgeoning population. Emissions are also changing due to alterations in land use. This paper describes some of the tropospheric chemistry associated with the Anthropocene, with emphasis on areas having large uncertainties. These include heterogeneous chemistry such as those of oxides of nitrogen and the neonicotinoid pesticides, reactions at liquid interfaces, organic oxidations and particle formation, the role of sulfur compounds in the Anthropocene and biogenic-anthropogenic interactions. A clear and quantitative understanding of the connections between emissions, reactions, deposition and atmospheric composition is central to developing appropriate cost-effective strategies for minimizing the impacts of anthropogenic activities. The evolving nature of emissions in the Anthropocene places atmospheric chemistry at the fulcrum of determining human health and welfare in the future.

  6. The Relationship between Chemistry Self-Efficacy of South African First Year University Students and Their Academic Performance

    Science.gov (United States)

    Ramnarain, Umesh; Ramaila, Sam

    2018-01-01

    This study investigated the self-efficacy of first-year Chemistry students at a South African university. The research involved a quantitative survey of 333 students using the College Chemistry Self-Efficacy Scale (CCSS) developed by Uzuntiryaki and Capa Aydin (2009). Descriptive statistics on data for the CCSS scales suggested that students have…

  7. From transistor to trapped-ion computers for quantum chemistry.

    Science.gov (United States)

    Yung, M-H; Casanova, J; Mezzacapo, A; McClean, J; Lamata, L; Aspuru-Guzik, A; Solano, E

    2014-01-07

    Over the last few decades, quantum chemistry has progressed through the development of computational methods based on modern digital computers. However, these methods can hardly fulfill the exponentially-growing resource requirements when applied to large quantum systems. As pointed out by Feynman, this restriction is intrinsic to all computational models based on classical physics. Recently, the rapid advancement of trapped-ion technologies has opened new possibilities for quantum control and quantum simulations. Here, we present an efficient toolkit that exploits both the internal and motional degrees of freedom of trapped ions for solving problems in quantum chemistry, including molecular electronic structure, molecular dynamics, and vibronic coupling. We focus on applications that go beyond the capacity of classical computers, but may be realizable on state-of-the-art trapped-ion systems. These results allow us to envision a new paradigm of quantum chemistry that shifts from the current transistor to a near-future trapped-ion-based technology.

  8. News from Online: Green Chemistry

    Science.gov (United States)

    Uffelman, Erich S.

    2004-01-01

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

  9. Chemistry Teachers' Views of Creativity

    Science.gov (United States)

    Akkanat, Çigdem; Gökdere, Murat

    2015-01-01

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

  10. How fast is ultrafast chemistry

    OpenAIRE

    Bagchi, Biman

    1995-01-01

    The field of ultrafast chemistry has seen a string of remarkable discoveries in the recent years. In this article we briefly discuss some of the problems solved recently. The understanding that has emerged from these studies has important consequences non only in chemistry but also in diverse biological processes.

  11. Modern Trends in Inorganic Chemistry

    Indian Academy of Sciences (India)

    Administrator

    The series of symposia on 'Modern Trends in Inorganic Chemistry' (MTIC), which began in 1985 at the Indian Association for Cultivation of Science, Calcutta has evolved into a forum for the Inorganic Chemistry fraternity of the country to meet every two years and discuss the current status and future projections of research in.

  12. Plasma chemistry and its applications

    Science.gov (United States)

    Hozumi, K.

    1980-01-01

    The relationship between discharge phenomena and plasma chemistry, as well as the equipment and mechanisms of plasma chemical reactions are described. Various areas in which plasma chemistry is applied are surveyed, such as: manufacturing of semiconductor integrated circuits; synthetic fibers; high polymer materials for medical uses; optical lenses; and membrane filters (reverse penetration films).

  13. Introducing Relativity into Quantum Chemistry

    Science.gov (United States)

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

    2011-01-01

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

  14. Contextualising Nanotechnology in Chemistry Education

    Science.gov (United States)

    O'Connor, Christine; Hayden, Hugh

    2008-01-01

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

  15. New Thinking in School Chemistry.

    Science.gov (United States)

    Organisation for Economic Cooperation and Development, Paris (France).

    This report contains the text of addresses given at a seminar on the status and development of the teaching of secondary school chemistry held in 1960 by the Organization for European Economic Development (now the Organization for Economic Cooperation and Development). The speakers considered advances in theoretical chemistry since 1900, the…

  16. Rethinking Undergraduate Physical Chemistry Curricula

    Science.gov (United States)

    Miller, Stephen R.

    2016-01-01

    A summary of fundamental changes made to the undergraduate physical chemistry curriculum in the Chemistry Department at Gustavus Adolphus College (beginning in the 2013-2014 academic year) is presented. The yearlong sequence now consists of an introductory semester covering both quantum mechanics and thermodynamics/kinetics, followed by a second…

  17. Refresher Course in Experimental Chemistry

    Indian Academy of Sciences (India)

    Srimath

    diverse topics such as chemical kinetics, electrochemistry, spectrophotometry, polymer chemistry, advanced synthesis in inorganic and organic chemistry and molecular modelling. The focus of this. Course is to acquaint the participants with novel avenues of sensitizing the students at the undergraduate level about the ...

  18. Organic chemistry on Titan

    Science.gov (United States)

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

    1979-01-01

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

  19. Getting Hooked on Chemistry

    Science.gov (United States)

    Mason, Diana S.

    2002-04-01

    Other fun things in this issue include three Quote Boxes by Olney (3) that will allow your students to engage in deductive reasoning to solve the puzzles. Kelkar (4) presents a slightly more difficult but very clever mystery element game; it provides clues to element symbols that all fit into a single matrix. Ibanez's game (5) lists popular sayings or proverbs and the student's job is to match each with an analogous chemical phenomenon. As always, answers are provided. For the more sophisticated among us, there is Who Wants to Be a Chemist Extraordinaire? devised by Campbell and Muzyka (6), who describe their use of online chemistry game shows patterned on popular TV programs. Examples of the HTML files with sample questions are available through JCE Online. These are just some of the many suggestions that can be found in this issue of JCE. Try a few, you might like them!

  20. Introduction to structural chemistry

    CERN Document Server

    Batsanov, Stepan S

    2014-01-01

    A concise description of models and quantitative parameters in structural chemistry and their interrelations, with 280 tables and >3000 references giving the most up-to-date experimental data on energy characteristics of atoms, molecules and crystals (ionisation potentials, electron affinities, bond energies, heats of phase transitions, band and lattice energies), optical properties (refractive index, polarisability), spectroscopic characteristics and geometrical parameters (bond distances and angles, coordination numbers) of substances in gaseous, liquid and solid states, in glasses and melts, for various thermodynamic conditions. Systems of metallic, covalent, ionic and van der Waals radii, effective atomic charges and other empirical and semi-empirical models are critically revised. Special attention is given to new and growing areas: structural studies of solids under high pressures and van der Waals molecules in gases. The book is addressed to researchers, academics, postgraduates and advanced-course stu...