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Sample records for advanced chemistry ilpac

  1. Independent Learning Project for Advanced Chemistry (ILPAC). Teachers' and Technicians' Notes for First Year Units.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    The Independent Learning Project for Advanced Chemistry (ILPAC) has produced units of study for students in A-level chemistry. Students completing ILPAC units assume a greater responsibility for their own learning and can work, to some extent, at their own pace. By providing guidance, and detailed solutions to exercises in the units, supported by…

  2. s-Block Elements. Independent Learning Project for Advanced Chemistry (ILPAC). Unit I1.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two sections and an appendix, focuses on the elements and compounds of Groups I and II (the s-block) of the periodic table. The groups are treated concurrently to note comparisons between groups and to…

  3. Hydrocarbons. Independent Learning Project for Advanced Chemistry (ILPAC). Unit O1.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on hydrocarbons is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit is divided into sections dealing with alkanes, alkenes, alkynes, arenes, and several aspects of the petroleum industry. Two experiments, exercises (with answers), and pre- and post-tests are included.…

  4. Equilibrium I: Principles. Independent Learning Project for Advanced Chemistry (ILPAC). Unit P2.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on the principles of equilibrium is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit consists of two levels. After a treatment of non-mathematical aspects in level one (the idea of a reversible reaction, characteristics of an equilibrium state, the Le Chatelier's principle),…

  5. The Halogens. Independent Learning Project for Advanced Chemistry (ILPAC). Unit I2.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, focuses on the elements and compounds of Group IV (halogens) of the periodic table. Level one deals with the physical and chemical properties of the individual elements. Level two considers…

  6. Atomic Structure. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S2.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on atomic structure is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit consists of two levels. Level one focuses on the atomic nucleus. Level two focuses on the arrangement of extranuclear electrons, approaching atomic orbitals through both electron bombardment and spectra.…

  7. The Mole. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S1.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on the mole is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, designed to help students consolidate some of the ideas about the mole learned in previous courses, consists of two levels. The first level focuses on: (1) relative mass; (2) the concept of the mole as the unit…

  8. Chemical Energetics. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S3.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on chemical energetics is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, provides a clear yet detailed and thorough introduction to the topic. Level one extends ideas from previous courses, introduces and emphasizes the importance of Hess'…

  9. The Gaseous State. Independent Learning Project for Advanced Chemistry (ILPAC). Unit P1.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on the gaseous state is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit consists of two levels. Level one deals with the distinctive characteristics of gases, then considers the gas laws, in particular the ideal gas equation and its applications. Level two concentrates on…

  10. Bonding and Structure. Independent Learning Project for Advanced Chemistry (ILPAC). Unit S4.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on chemical bonding is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, provides an introduction to the main types of chemical bonding and important aspects of structure. The main emphasis is placed on such topics as ionic and covalent bonding,…

  11. Equilibrium II: Acids and Bases. Independent Learning Project for Advanced Chemistry (ILPAC). Unit P3.

    ERIC Educational Resources Information Center

    Inner London Education Authority (England).

    This unit on equilibrium is one of 10 first year units produced by the Independent Learning Project for Advanced Chemistry (ILPAC). The unit, which consists of two levels, focuses on the application of equilibrium principles to equilibria involving weak acids and bases, including buffer solutions and indicators. Level one uses Le Chatelier's…

  12. ADVANCED CHEMISTRY BASINS MODEL

    SciTech Connect

    William Goddard III; Lawrence Cathles III; Mario Blanco; Paul Manhardt; Peter Meulbroek; Yongchun Tang

    2004-05-01

    The advanced Chemistry Basin Model project has been operative for 48 months. During this period, about half the project tasks are on projected schedule. On average the project is somewhat behind schedule (90%). Unanticipated issues are causing model integration to take longer then scheduled, delaying final debugging and manual development. It is anticipated that a short extension will be required to fulfill all contract obligations.

  13. An Advanced Chemistry Laboratory Program.

    ERIC Educational Resources Information Center

    Wise, John H.

    The Advanced Chemistry Laboratory Program is a project designed to devise experiments to coordinate the use of instruments in the laboratory programs of physical chemistry, instrumental analysis, and inorganic chemistry at the advanced undergraduate level. It is intended that such experiments would incorporate an introduction to the instrument…

  14. Advanced Chemistry Basins Model

    SciTech Connect

    William Goddard; Mario Blanco; Lawrence Cathles; Paul Manhardt; Peter Meulbroek; Yongchun Tang

    2002-11-10

    The DOE-funded Advanced Chemistry Basin model project is intended to develop a public domain, user-friendly basin modeling software under PC or low end workstation environment that predicts hydrocarbon generation, expulsion, migration and chemistry. The main features of the software are that it will: (1) afford users the most flexible way to choose or enter kinetic parameters for different maturity indicators; (2) afford users the most flexible way to choose or enter compositional kinetic parameters to predict hydrocarbon composition (e.g., gas/oil ratio (GOR), wax content, API gravity, etc.) at different kerogen maturities; (3) calculate the chemistry, fluxes and physical properties of all hydrocarbon phases (gas, liquid and solid) along the primary and secondary migration pathways of the basin and predict the location and intensity of phase fractionation, mixing, gas washing, etc.; and (4) predict the location and intensity of de-asphaltene processes. The project has be operative for 36 months, and is on schedule for a successful completion at the end of FY 2003.

  15. Advances in analytical chemistry

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  16. Advanced Chemistry Basins Model

    SciTech Connect

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

    2003-02-13

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

  17. Advanced fuel chemistry for advanced engines.

    SciTech Connect

    Taatjes, Craig A.; Jusinski, Leonard E.; Zador, Judit; Fernandes, Ravi X.; Miller, James A.

    2009-09-01

    Autoignition chemistry is central to predictive modeling of many advanced engine designs that combine high efficiency and low inherent pollutant emissions. This chemistry, and especially its pressure dependence, is poorly known for fuels derived from heavy petroleum and for biofuels, both of which are becoming increasingly prominent in the nation's fuel stream. We have investigated the pressure dependence of key ignition reactions for a series of molecules representative of non-traditional and alternative fuels. These investigations combined experimental characterization of hydroxyl radical production in well-controlled photolytically initiated oxidation and a hybrid modeling strategy that linked detailed quantum chemistry and computational kinetics of critical reactions with rate-equation models of the global chemical system. Comprehensive mechanisms for autoignition generally ignore the pressure dependence of branching fractions in the important alkyl + O{sub 2} reaction systems; however we have demonstrated that pressure-dependent 'formally direct' pathways persist at in-cylinder pressures.

  18. Recent Advances in Azaborine Chemistry

    PubMed Central

    Campbell, Patrick G.; Marwitz, Adam J. V.

    2013-01-01

    The chemistry of organoboron compounds has been primarily dominated by their use as powerful reagents in synthetic organic chemistry. Recently, the incorporation of boron as part of a functional target structure has emerged as a useful way to generate diversity in organic compounds. A commonly applied strategy is the replacement of a CC unit with its isoelectronic BN unit. In particular, the BN/CC isosterism of the ubiquitous arene motif has undergone a renaissance in the past decade. The parent molecule of the 1,2-dihydro-1,2-azaborine family has now been isolated. New mono- and polycyclic BN heterocycles have been synthesized for potential use in biomedical and materials science applications. This review is a tribute to Dewar's first synthesis of a monocyclic 1,2-dihydro-1,2-azaborine 50 years ago and discusses recent advances in the synthesis and characterization of carbon(C)-boron(B)-nitrogen(N)-containing heterocycles. PMID:22644658

  19. THE ADVANCED CHEMISTRY BASINS PROJECT

    SciTech Connect

    William Goddard; Peter Meulbroek; Yongchun Tang; Lawrence Cathles III

    2004-04-05

    In the next decades, oil exploration by majors and independents will increasingly be in remote, inaccessible areas, or in areas where there has been extensive shallow exploration but deeper exploration potential may remain; areas where the collection of data is expensive, difficult, or even impossible, and where the most efficient use of existing data can drive the economics of the target. The ability to read hydrocarbon chemistry in terms of subsurface migration processes by relating it to the evolution of the basin and fluid migration is perhaps the single technological capability that could most improve our ability to explore effectively because it would allow us to use a vast store of existing or easily collected chemical data to determine the major migration pathways in a basin and to determine if there is deep exploration potential. To this end a the DOE funded a joint effort between California Institute of Technology, Cornell University, and GeoGroup Inc. to assemble a representative set of maturity and maturation kinetic models and develop an advanced basin model able to predict the chemistry of hydrocarbons in a basin from this input data. The four year project is now completed and has produced set of public domain maturity indicator and maturation kinetic data set, an oil chemistry and flash calculation tool operable under Excel, and a user friendly, graphically intuitive basin model that uses this data and flash tool, operates on a PC, and simulates hydrocarbon generation and migration and the chemical changes that can occur during migration (such as phase separation and gas washing). The DOE Advanced Chemistry Basin Model includes a number of new methods that represent advances over current technology. The model is built around the concept of handling arbitrarily detailed chemical composition of fluids in a robust finite-element 2-D grid. There are three themes on which the model focuses: chemical kinetic and equilibrium reaction parameters, chemical

  20. Advanced diagnostics for plasma chemistry

    SciTech Connect

    Kruger, C.H.

    1994-03-01

    Since July 15, 1992, the High Temperature Gasdynamics Laboratory in the Department of Mechanical Engineering at Stanford University has been engaged in a four-year research program on Advanced Diagnostics for Plasma Chemistry. The goal of this program is to develop state-of-the-art laser-based diagnostics of molecular species in harsh chemical environments, particularly those encountered in plasma synthesis of new materials. Emphasis has been placed on exploiting a new nonlinear spectroscopy, degenerate four wave mixing, as well as linear laser induced fluorescence to accomplish these goals. The present submittal is a proposal for the continuation funding for the third year of this program, from July 15, 1994, until July 14, 1995. Section 2 summarizes the research accomplished during the first eighteen months of the program. Section 3 discusses the plans for continuing research activities. Publications and presentations to date resulting from this program are listed in Section 4. The proposed budget for the third year is given in Section 5.

  1. Advanced Placement Chemistry: Project Advance and the Advanced Placement Program: A Comparison of Students' Performance on the AP Chemistry Examination.

    ERIC Educational Resources Information Center

    Mercurio, Joseph; And Others

    1984-01-01

    Compared performance of Syracuse University Project Advance (PA) chemistry students (N=35) with advanced placement (AP) candidates on the AP chemistry examination. PA students scored slightly above the national average on the examination, and students who performed well (B or better) in AP chemistry also did well on the examination. (JN)

  2. Advancing manufacturing through computational chemistry

    SciTech Connect

    Noid, D.W.; Sumpter, B.G.; Tuzun, R.E.

    1995-12-31

    The capabilities of nanotechnology and computational chemistry are reaching a point of convergence. New computer hardware and novel computational methods have created opportunities to test proposed nanometer-scale devices, investigate molecular manufacturing and model and predict properties of new materials. Experimental methods are also beginning to provide new capabilities that make the possibility of manufacturing various devices with atomic precision tangible. In this paper, we will discuss some of the novel computational methods we have used in molecular dynamics simulations of polymer processes, neural network predictions of new materials, and simulations of proposed nano-bearings and fluid dynamics in nano- sized devices.

  3. Photoelectron Spectroscopy in Advanced Placement Chemistry

    ERIC Educational Resources Information Center

    Benigna, James

    2014-01-01

    Photoelectron spectroscopy (PES) is a new addition to the Advanced Placement (AP) Chemistry curriculum. This article explains the rationale for its inclusion, an overview of how the PES instrument records data, how the data can be analyzed, and how to include PES data in the course. Sample assessment items and analysis are included, as well as…

  4. Radiation Chemistry of Advanced TALSPEAK Flowsheet

    SciTech Connect

    Mincher, Bruce; Peterman, Dean; Mcdowell, Rocklan; Olson, Lonnie; Lumetta, Gregg J.

    2013-08-28

    This report summarizes the results of initial experiments designed to understand the radiation chemistry of an Advanced TALSPEAK process for separating trivalent lanthanides form the actinides. Biphasic aerated samples were irradiated and then analyzed for post-irradiation constituent concentrations and solvent extraction distribution ratios. The effects of irradiation on the TALSPEAK and Advanced TALSPEAK solvents were similar, with very little degradation of the organic phase extractant. Decomposition products were detected, with a major product in common for both solvents. This product may be responsible for the slight increase in distribution ratios for Eu and Am with absorbed dose, however; separation factors were not greatly affected.

  5. Advanced Chemistry Collection, 2nd Edition

    NASA Astrophysics Data System (ADS)

    2001-11-01

    Software requirements are given in Table 3. Some programs have additional special requirements. Please see the individual program abstracts at JCE Online or the documentation included on the CD-ROM for more specific information. Table 3. General software requirements for the Advanced Chemistry Collection.

    ComputerSystemOther Software(Required by one or more programs)
    Mac OS compatibleSystem 7.6.1 or higherAcrobat Reader (included)Mathcad; Mathematica;MacMolecule2; QuickTime 4; HyperCard Player
    Windows CompatibleWindows 2000, 98, 95, NT 4Acrobat Reader (included)Mathcad; Mathematica;PCMolecule2; QuickTime 4;HyperChem; Excel

    Literature Cited

    1. General Chemistry Collection, 5th ed.; J. Chem. Educ. Software, 2001, SP16.
    2. Advanced Chemistry Collection; J. Chem. Educ. Software, 2001, SP28.

  6. Recent advances in computational actinoid chemistry.

    PubMed

    Wang, Dongqi; van Gunsteren, Wilfred F; Chai, Zhifang

    2012-09-01

    We briefly review advances in computational actinoid (An) chemistry during the past ten years in regard to two issues: the geometrical and electronic structures, and reactions. The former addresses the An-O, An-C, and M-An (M is a metal atom including An) bonds in the actinoid molecular systems, including actinoid oxo and oxide species, actinoid-carbenoid, dinuclear and diatomic systems, and the latter the hydration and ligand exchange, the disproportionation, the oxidation, the reduction of uranyl, hydroamination, and the photolysis of uranium azide. Concerning their relevance to the electronic structures and reactions of actinoids and their importance in the development of an advanced nuclear fuel cycle, we also mentioned the work on actinoid carbides and nitrides, which have been proposed to be candidates of the next generation of nuclear fuel, and the oxidation of PuO(x), which is important to understand the speciation of actinoids in the environment, followed by a brief discussion on the urgent need for a heavier involvement of computational actinoid chemistry in developing advanced reprocessing protocols of spent nuclear fuel. The paper is concluded with an outlook. PMID:22777520

  7. Integrating Advanced High School Chemistry Research with Organic Chemistry and Instrumental Methods of Analysis

    ERIC Educational Resources Information Center

    Kennedy, Brian J.

    2008-01-01

    This paper describes and discusses the unique chemistry course opportunities beyond the advanced placement-level available at a science and technology magnet high school. Students may select entry-level courses such as honors and advanced placement chemistry; they may also take electives in organic chemistry with instrumental methods of analysis;…

  8. Computing Advances in the Teaching of Chemistry.

    ERIC Educational Resources Information Center

    Baskett, W. P.; Matthews, G. P.

    1984-01-01

    Discusses three trends in computer-oriented chemistry instruction: (1) availability of interfaces to integrate computers with experiments; (2) impact of the development of higher resolution graphics and greater memory capacity; and (3) role of videodisc technology on computer assisted instruction. Includes program listings for auto-titration and…

  9. Recent advances in technetium halide chemistry.

    PubMed

    Poineau, Frederic; Johnstone, Erik V; Czerwinski, Kenneth R; Sattelberger, Alfred P

    2014-02-18

    Transition metal binary halides are fundamental compounds, and the study of their structure, bonding, and other properties gives chemists a better understanding of physicochemical trends across the periodic table. One transition metal whose halide chemistry is underdeveloped is technetium, the lightest radioelement. For half a century, the halide chemistry of technetium has been defined by three compounds: TcF6, TcF5, and TcCl4. The absence of Tc binary bromides and iodides in the literature was surprising considering the existence of such compounds for all of the elements surrounding technetium. The common synthetic routes that scientists use to obtain binary halides of the neighboring elements, such as sealed tube reactions between elements and flowing gas reactions between a molecular complex and HX gas (X = Cl, Br, or I), had not been reported for technetium. In this Account, we discuss how we used these routes to revisit the halide chemistry of technetium. We report seven new phases: TcBr4, TcBr3, α/β-TcCl3, α/β-TcCl2, and TcI3. Technetium tetrachloride and tetrabromide are isostructural to PtX4 (X = Cl or Br) and consist of infinite chains of edge-sharing TcX6 octahedra. Trivalent technetium halides are isostructural to ruthenium and molybdenum (β-TcCl3, TcBr3, and TcI3) and to rhenium (α-TcCl3). Technetium tribromide and triiodide exhibit the TiI3 structure-type and consist of infinite chains of face-sharing TcX6 (X = Br or I) octahedra. Concerning the trichlorides, β-TcCl3 crystallizes with the AlCl3 structure-type and consists of infinite layers of edge-sharing TcCl6 octahedra, while α-TcCl3 consists of infinite layers of Tc3Cl9 units. Both phases of technetium dichloride exhibit new structure-types that consist of infinite chains of [Tc2Cl8] units. For the technetium binary halides, we studied the metal-metal interaction by theoretical methods and magnetic measurements. The change of the electronic configuration of the metal atom from d(3) (Tc

  10. Recent advances in click chemistry applied to dendrimer synthesis.

    PubMed

    Arseneault, Mathieu; Wafer, Caroline; Morin, Jean-François

    2015-01-01

    Dendrimers are monodisperse polymers grown in a fractal manner from a central point. They are poised to become the cornerstone of nanoscale devices in several fields, ranging from biomedicine to light-harvesting. Technical difficulties in obtaining these molecules has slowed their transfer from academia to industry. In 2001, the arrival of the "click chemistry" concept gave the field a major boost. The flagship reaction, a modified Hüisgen cycloaddition, allowed researchers greater freedom in designing and building dendrimers. In the last five years, advances in click chemistry saw a wider use of other click reactions and a notable increase in the complexity of the reported structures. This review covers key developments in the click chemistry field applied to dendrimer synthesis from 2010 to 2015. Even though this is an expert review, basic notions and references have been included to help newcomers to the field. PMID:26007183

  11. Research for the advancement of green chemistry practice: Studies in atmospheric and educational chemistry

    NASA Astrophysics Data System (ADS)

    Cullipher, Steven Gene

    Green chemistry is a philosophy of chemistry that emphasizes a decreasing dependence on limited non-renewable resources and an increasing focus on preventing pollution byproducts of the chemical industry. In short, it is the discipline of chemistry practiced through the lens of environmental stewardship. In an effort to advance the practice of green chemistry, three studies will be described that have ramifications for the practice. The first study examines the atmospheric oxidation of a hydrofluorinated ether, a third-generation CFC replacement compound with primarily unknown atmospheric degradation products. Determination of these products has the potential to impact decisions on refrigerant usage in the future. The second study examines chemistry students' development of understanding benefits-costs-risks analysis when presented with two real-world scenarios: refrigerant choice and fuel choice. By studying how benefits-costs-risks thinking develops, curricular materials and instructional approaches can be designed to better foster the development of an ability that is both necessary for green chemists and important in daily decision-making for non-chemists. The final study uses eye tracking technology to examine students' abilities to interpret molecular properties from structural information in the context of global warming. Such abilities are fundamental if chemists are to appropriately assess risks and hazards of chemistry practice.

  12. Advances in actinide solid-state and coordination chemistry

    SciTech Connect

    Burns, Peter C; Ikeda, Y.; Czerwinski, K.

    2011-01-31

    Actinide solid-state and coordination chemistry has advanced through unexpected results that have further revealed the complex nature of the 5f elements. Nanoscale control of actinide materials is emerging, as shown by the creation of a considerable range of cluster and tubular topologies. Departures from established structural trends for actinyl ions are provided by cation-cation interactions in which an O atom of one actinyl ion is an equatorial ligand of a bipyramid of another actinyl ion. The solid-state structural complexity of actinide materials has been further demonstrated by open framework materials with interesting properties. The U(VI) tetraoxide core has been added to this cation's repertoire of coordination possibilities. The emergence of pentavalent uranium solid-state and coordination chemistry has resulted from the prudent selection of ligands. Finally, analogues of the uranyl ion have challenged our understanding of this normally unreactive functional group.

  13. Adapting Advanced Inorganic Chemistry Lecture and Laboratory Instruction for a Legally Blind Student

    ERIC Educational Resources Information Center

    Miecznikowski, John R.; Guberman-Pfeffer, Matthew J.; Butrick, Elizabeth E.; Colangelo, Julie A.; Donaruma, Cristine E.

    2015-01-01

    In this article, the strategies and techniques used to successfully teach advanced inorganic chemistry, in the lecture and laboratory, to a legally blind student are described. At Fairfield University, these separate courses, which have a physical chemistry corequisite or a prerequisite, are taught for junior and senior chemistry and biochemistry…

  14. Modern advances in heterocyclic chemistry in drug discovery.

    PubMed

    Taylor, Alexandria P; Robinson, Ralph P; Fobian, Yvette M; Blakemore, David C; Jones, Lyn H; Fadeyi, Olugbeminiyi

    2016-07-12

    New advances in synthetic methodologies that allow rapid access to a wide variety of functionalized heterocyclic compounds are of critical importance to the medicinal chemist as it provides the ability to expand the available drug-like chemical space and drive more efficient delivery of drug discovery programs. Furthermore, the development of robust synthetic routes that can readily generate bulk quantities of a desired compound help to accelerate the drug development process. While established synthetic methodologies are commonly utilized during the course of a drug discovery program, the development of innovative heterocyclic syntheses that allow for different bond forming strategies are having a significant impact in the pharmaceutical industry. This review will focus on recent applications of new methodologies in C-H activation, photoredox chemistry, borrowing hydrogen catalysis, multicomponent reactions, regio- and stereoselective syntheses, as well as other new, innovative general syntheses for the formation and functionalization of heterocycles that have helped drive project delivery. Additionally, the importance and value of collaborations between industry and academia in shaping the development of innovative synthetic approaches to functionalized heterocycles that are of greatest interest to the pharmaceutical industry will be highlighted. PMID:27282396

  15. Nanomaterial surface chemistry design for advancements in capillary electrophoresis modes.

    PubMed

    Ivanov, Michael R; Haes, Amanda J

    2011-01-01

    Tailored surface chemistry impacts nanomaterial function and stability in applications including in various capillary electrophoresis (CE) modes. Although colloidal nanoparticles were first integrated as colouring agents in artwork and pottery over 2000 years ago, recent developments in nanoparticle synthesis and surface modification increased their usefulness and incorporation in separation science. For instance, precise control of surface chemistry is critically important in modulating nanoparticle functionality and stability in dynamic environments. Herein, recent developments in nanomaterial pseudostationary and stationary phases will be summarized. First, nanomaterial core and surface chemistry compositions will be classified. Next, characterization methods will be described and related to nanomaterial function in various CE modes. Third, methods and implications of nanomaterial incorporation into CE will be discussed. Finally, nanoparticle-specific mechanisms likely involved in CE will be related to nanomaterial surface chemistry. Better understanding of surface chemistry will improve nanoparticle design for the integration into separation techniques. PMID:20967383

  16. Integration of a Communicating Science Module into an Advanced Chemistry Laboratory Course

    ERIC Educational Resources Information Center

    Renaud, Jessica; Squier, Christopher; Larsen, Sarah C.

    2006-01-01

    A communicating science module was introduced into an advanced undergraduate physical chemistry laboratory course. The module was integrated into the course such that students received formal instruction in communicating science interwoven with the chemistry laboratory curriculum. The content of the communicating science module included three…

  17. What Does a Student Know Who Earns a Top Score on the Advanced Placement Chemistry Exam?

    ERIC Educational Resources Information Center

    Claesgens, Jennifer; Daubenmire, Paul L.; Scalise, Kathleen M.; Balicki, Scott; Gochyyev, Perman; Stacy, Angelica M.

    2014-01-01

    This paper compares the performance of students at a high-performing U.S. public school (n = 64) on the advanced placement (AP) chemistry exam to their performance on the ChemQuery assessment system. The AP chemistry exam was chosen because, as the National Research Council acknowledges, it is the "perceived standard of excellence and school…

  18. Development of an Advanced Training Course for Teachers and Researchers in Chemistry

    ERIC Educational Resources Information Center

    Dragisich, Vera; Keller, Valerie; Black, Rebecca; Heaps, Charles W.; Kamm, Judith M.; Olechnowicz, Frank; Raybin, Jonathan; Rombola, Michael; Zhao, Meishan

    2016-01-01

    Based on our long-standing Intensive Training Program for Effective Teaching Assistants in Chemistry, we have developed an Advanced Training Course for Teachers and Researchers in Chemistry at The University of Chicago. The topics in this course are designed to train graduate teaching assistants (GTAs) to become effective teachers and well-rounded…

  19. ADVANCES IN GREEN CHEMISTRY: CHEMICAL SYNTHESES USING MICROWAVE IRRADIATION, ISBN 81-901238-5-8

    EPA Science Inventory

    16. Abstract Advances in Green Chemistry: Chemical Syntheses Using Microwave Irradiation
    Microwave-accelerated chemical syntheses in solvents as well as under solvent-free conditions have witnessed an explosive growth. The technique has found widespread application predomi...

  20. Surface chemistry: Key to control and advance myriad technologies

    PubMed Central

    Yates, John T.; Campbell, Charles T.

    2011-01-01

    This special issue on surface chemistry is introduced with a brief history of the field, a summary of the importance of surface chemistry in technological applications, a brief overview of some of the most important recent developments in this field, and a look forward to some of its most exciting future directions. This collection of invited articles is intended to provide a snapshot of current developments in the field, exemplify the state of the art in fundamental research in surface chemistry, and highlight some possibilities in the future. Here, we show how those articles fit together in the bigger picture of this field. PMID:21245359

  1. Assessing Advanced High School and Undergraduate Students' Thinking Skills: The Chemistry--From the Nanoscale to Microelectronics Module

    ERIC Educational Resources Information Center

    Dori, Yehudit Judy; Dangur, Vered; Avargil, Shirly; Peskin, Uri

    2014-01-01

    Chemistry students in Israel have two options for studying chemistry: basic or honors (advanced placement). For instruction in high school honors chemistry courses, we developed a module focusing on abstract topics in quantum mechanics: Chemistry--From the Nanoscale to Microelectronics. The module adopts a visual-conceptual approach, which…

  2. Advances in atmospheric chemistry modeling: the LLNL impact tropospheric/stratospheric chemistry model

    SciTech Connect

    Rotman, D A; Atherton, C

    1999-10-07

    We present a unique modeling capability to understand the global distribution of trace gases and aerosols throughout both the troposphere and stratosphere. It includes the ability to simulate tropospheric chemistry that occurs both in the gas phase as well as on the surfaces of solid particles. We have used this capability to analyze observations from particular flight campaigns as well as averaged observed data. Results show the model to accurately simulate the complex chemistry occurring near the tropopause and throughout the troposphere and stratosphere.

  3. A Selection of Recent Advances in C1 Chemistry.

    PubMed

    Mesters, Carl

    2016-06-01

    This review presents a selection of recent publications related to the chemistry and catalysis of C1 molecules, including methane, methanol, carbon monoxide, and carbon dioxide. These molecules play an important role in the current supply of energy and chemicals and will likely become even more relevant because of the need to decarbonize fuels (shift from coal to natural gas) in line with CO2 capture and use to mitigate global warming, as well as a gradual shift on the supply side from crude oil to natural gas. This review includes both recent industrial developments, such as the huge increase in methanol-to-olefins-capacity build in China and the demonstration of oxidative coupling of methane, and scientific developments in these chemistries facilitated by improved capabilities in, for example, analytical tools and computational modeling. PMID:27276549

  4. Continuous Symmetry and Chemistry Teachers: Learning Advanced Chemistry Content through Novel Visualization Tools

    ERIC Educational Resources Information Center

    Tuvi-Arad, Inbal; Blonder, Ron

    2010-01-01

    In this paper we describe the learning process of a group of experienced chemistry teachers in a specially designed workshop on molecular symmetry and continuous symmetry. The workshop was based on interactive visualization tools that allow molecules and their symmetry elements to be rotated in three dimensions. The topic of continuous symmetry is…

  5. Advances in Chemistry and Bioactivity of the Genus Chisocheton Blume.

    PubMed

    Shilpi, Jamil A; Saha, Sanjib; Chong, Soon-Lim; Nahar, Lutfun; Sarker, Satyajit D; Awang, Khalijah

    2016-05-01

    Chisocheton is one of the genera of the family Meliaceae and consists of ca. 53 species; the distribution of most of those are confined to the Indo-Malay region. Species of broader geographic distribution have undergone extensive phytochemical investigations. Previous phytochemical investigations of this genus resulted in the isolation of mainly limonoids, apotirucallane, tirucallane, and dammarane triterpenes. Reported bioactivities of the isolated compounds include cytotoxic, anti-inflammatory, antifungal, antimalarial, antimycobacterial, antifeedant, and lipid droplet inhibitory activities. Aside from chemistry and biological activities, this review also deals briefly with botany, distribution, and uses of various species of this genus. PMID:26970405

  6. Advances in solid-phase extraction disks for environmental chemistry

    USGS Publications Warehouse

    Thurman, E.M.; Snavely, K.

    2000-01-01

    The development of solid-phase extraction (SPE) for environmental chemistry has progressed significantly over the last decade to include a number of new sorbents and new approaches to SPE. One SPE approach in particular, the SPE disk, has greatly reduced or eliminated the use of chlorinated solvents for the analysis of trace organic compounds. This article discusses the use and applicability of various SPE disks, including micro-sized disks, prior to gas chromatography-mass spectrometry for the analysis of trace organic compounds in water. Copyright (C) 2000 Elsevier Science B.V.

  7. Visualizing Chemistry: The Progess and Promise of Advanced Chemical Imaging

    SciTech Connect

    Committee on Revealing Chemistry Through Advanced Chemical Imaging

    2006-09-01

    The field of chemical imaging can provide detailed structural, functional, and applicable information about chemistry and chemical engineering phenomena that have enormous impacts on medicine, materials, and technology. In recognizing the potential for more research development in the field of chemical imaging, the National Academies was asked by the National Science Foundation, Department of Energy, U.S. Army, and National Cancer Institute to complete a study that would review the current state of molecular imaging technology, point to promising future developments and their applications, and suggest a research and educational agenda to enable breakthrough improvements in the ability to image molecular processes simultaneously in multiple physical dimensions as well as time. The study resulted in a consensus report that provides guidance for a focused research and development program in chemical imaging and identifies research needs and possible applications of imaging technologies that can provide the breakthrough knowledge in chemistry, materials science, biology, and engineering for which we should strive. Public release of this report is expected in early October.

  8. Integrative Chemistry: Advanced functional cellular materials bearing multiscale porosity

    NASA Astrophysics Data System (ADS)

    Depardieu, M.; Kinadjian, N.; Backov, R.

    2015-07-01

    With this mini review we show through the sol-gel and emulsion-based Integrative Chemistry how it is possible to trigger materials dimensionality and beyond their functionalities when reaching enhanced applications. In here we focus on 3D macrocellular monolithic foams bearing hierarchical porosities and applications thereof. We first depict the general background of emulsions focusing on concentrated ones, acting as soft templates for the design of PolyHIPE foams, HIPE being the acronym of High Internal Phase Emulsions while encompassing both sol-gel and polymer chemistry. Secondly we extend this approach toward the design of hybrid organic-inorganic foams, labeled Organo-Si(HIPE), where photonics and heterogeneous catalysis applications are addressed. In a third section we show how inorganic Si(HIPE) matrices can be employed as sacrificial hard templates for the generation carbonaceous foams, labeled Carbon(HIPE). These foams being conductive we show applications when employed as electrodes for Li-S battery and as hosts for Li(BH4)-based hydrogen storage.

  9. A Simultaneous Analysis Problem for Advanced General Chemistry Laboratories.

    ERIC Educational Resources Information Center

    Leary, J. J.; Gallaher, T. N.

    1983-01-01

    Oxidation of magnesium metal in air has been used as an introductory experiment for determining the formula of a compound. The experiment described employs essentially the same laboratory procedure but is significantly more advanced in terms of information sought. Procedures and sample calculations/results are provided. (JN)

  10. Amphiphile nanoarchitectonics: from basic physical chemistry to advanced applications

    SciTech Connect

    Ramanathan, Nathan Muruganathan; Shrestha, Lok Kumar; Mori, Taizo; Ji, Dr. Qingmin; Hill, Dr. Jonathan P; Ariga, Katsuhiko

    2013-01-01

    Amphiphiles, either synthetic or natural, are structurally simple molecules with the unprecedented capacity to self-assemble into complex, hierarchical geometries in nanospace. Effective self-assembly processes of amphiphiles are often used to mimic biological systems, such as, assembly of lipids and proteins, which has paved a way for bottom-up nanotechnology with bio-like advanced functions. Recent developments on nanostructure formation combine simple processes of assembly with the more advanced concept of nanoarchitectonics. In this pespective, we summarize research on self-assembly of amphiphilic molecules such as lipids, surfactants or block copolymers that are a focus of interest for many colloid, polymer, and materials scientists and which have become increasingly important in emerging nanotechnology. Because the fundamental science of amphiphiles was initially developed for their solution assembly then transferred to assemblies on surfaces as a development of nanotechnological technique, this perspective attempts to mirro this development by introducing solution systems and progressing to interfacial systems, which are roughly categorized as (i) basic properties of amphiphiles, (ii) self-assembly of amphiphiles in bulk phases, (iii) assembly on static surfaces, (iv) assembly at dynamic interfaces, and (v) advanced topics from simulation to application. This progression also represents the evolution of amphiphile science and technology from simple assemblies to advanced assemblies to nanoarchitectonics.

  11. Amphiphile nanoarchitectonics: from basic physical chemistry to advanced applications.

    PubMed

    Ramanathan, Muruganathan; Shrestha, Lok Kumar; Mori, Taizo; Ji, Qingmin; Hill, Jonathan P; Ariga, Katsuhiko

    2013-07-14

    Amphiphiles, either synthetic or natural, are structurally simple molecules with the unprecedented capacity to self-assemble into complex, hierarchical geometries in nanospace. Effective self-assembly processes of amphiphiles are often used to mimic biological systems, such as assembly of lipids and proteins, which has paved a way for bottom-up nanotechnology with bio-like advanced functions. Recent developments in nanostructure formation combine simple processes of assembly with the more advanced concept of nanoarchitectonics. In this perspective, we summarize research on self-assembly of amphiphilic molecules such as lipids, surfactants or block copolymers that are a focus of interest for many colloid, polymer, and materials scientists and which have become increasingly important in emerging nanotechnology and practical applications, latter of which are often accomplished by amphiphile-like polymers. Because the fundamental science of amphiphiles was initially developed for their solution assembly then transferred to assemblies on surfaces as a development of nanotechnological techniques, this perspective attempts to mirror this development by introducing solution systems and progressing to interfacial systems, which are roughly categorized as (i) basic properties of amphiphiles, (ii) self-assembly of amphiphiles in bulk phases, (iii) assembly on static surfaces, (iv) assembly at dynamic interfaces, and (v) advanced topics from simulation to application. This progression also represents the evolution of amphiphile science and technology from simple assemblies to advanced assemblies to nanoarchitectonics. PMID:23639971

  12. Recent Advances in Glycerol Polymers: Chemistry and Biomedical Applications

    PubMed Central

    Zhang, Heng

    2015-01-01

    Glycerol polymers are attracting increased attention due to the diversity of polymer compositions and architectures available. This article provides a brief chronological review on the current status of these polymers along with representative examples of their use for biomedical applications. First, we describe the underlying chemistry of glycerol, which provides access to a range of monomers for subsequent polymerizations. We then review the various synthetic methodologies to prepare glycerol-based polymers including polyethers, polycarbonates, polyesters, and so forth. Next, we describe several biomedical applications where glycerol polymers are being investigated including carriers for drug delivery, sealants or coatings for tissue repair, and agents possessing antibacterial activity. Fourth, we describe the growing market opportunity for the use of polymers in medicine. Finally we conclude and summarize the findings, as well as discuss potential opportunities for continued research efforts. PMID:25308354

  13. ADVANCED SOLIDS NMR STUDIES OF COAL STRUCTURE AND CHEMISTRY

    SciTech Connect

    1997-09-01

    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. The main activity during this granting period was a completion of a detailed comparative analysis of the suite of spectral editing techniques developed in our laboratory for this purpose. The appended report is a manuscript being submitted to the Journal of Magnetic Resonance on this subject.

  14. ADVANCED SOLIDS NMR STUDIES OF COAL STRUCTURE AND CHEMISTRY

    SciTech Connect

    1998-03-01

    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. The main activity during this granting period was a detailed comparative analysis of the suite of spectral editing results obtained on the Argonne coals. We have extended our fitting procedure to include carbons of all types in the analysis.

  15. An Advanced Undergraduate Chemistry Laboratory Experiment Exploring NIR Spectroscopy and Chemometrics

    ERIC Educational Resources Information Center

    Wanke, Randall; Stauffer, Jennifer

    2007-01-01

    An advanced undergraduate chemistry laboratory experiment to study the advantages and hazards of the coupling of NIR spectroscopy and chemometrics is described. The combination is commonly used for analysis and process control of various ingredients used in agriculture, petroleum and food products.

  16. Integrating Project-Based Service-Learning into an Advanced Environmental Chemistry Course

    ERIC Educational Resources Information Center

    Draper, Alison J.

    2004-01-01

    An active service-learning research work is conducted in the field of advanced environmental chemistry. Multiple projects are assigned to students, which promote individual learning skills, self-confidence as scientists, and a deep understanding of the environmental chemist's profession.

  17. A Comprehensive Microfluidics Device Construction and Characterization Module for the Advanced Undergraduate Analytical Chemistry Laboratory

    ERIC Educational Resources Information Center

    Piunno, Paul A. E.; Zetina, Adrian; Chu, Norman; Tavares, Anthony J.; Noor, M. Omair; Petryayeva, Eleonora; Uddayasankar, Uvaraj; Veglio, Andrew

    2014-01-01

    An advanced analytical chemistry undergraduate laboratory module on microfluidics that spans 4 weeks (4 h per week) is presented. The laboratory module focuses on comprehensive experiential learning of microfluidic device fabrication and the core characteristics of microfluidic devices as they pertain to fluid flow and the manipulation of samples.…

  18. A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha M.; Bennett, William R.

    2010-01-01

    NASAs Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair Lunar Lander and the Extravehicular Activities (EVA) advanced Lunar surface spacesuit. These customers require safe, reliable batteries with extremely high specific energy as compared to state-of-the-art. The specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery-level at 0 degrees Celsius ( C) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation between 0 and 30 C and 200 cycles are targeted. Electrode materials that were considered include layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. Advanced cell chemistry options were evaluated with respect to multiple quantitative and qualitative attributes while considering their projected performance at the end of the available development timeframe. Following a rigorous ranking process, a chemistry that combines a lithiated nickel manganese cobalt oxide Li(LiNMC)O2 cathode with a silicon-based composite anode was selected as the technology that can potentially offer the best combination of safety, specific energy, energy density, and likelihood of success.

  19. ADVANCED SOLIDS NMR STUDIES OF COAL STRUCTURE AND CHEMISTRY

    SciTech Connect

    1997-03-01

    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 methane groups, identification of carbons adjacent to nitrogen and sites with exchangeable protons, and methods to more finely characterize the distribution of hydrogen in coals. The motivation for investigating these specific structural features of coals arises from their relevance to the chemical reactivity of coals, and their suitability for possible correlations with the oil sourcing potential 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. In this report period we have focused our work on 1 segment of the program. Our last report outlined progress in using our NMR editing methods with higher field operation where higher magic angle spinning rates are required. Significant difficulties were identified, and these have been the main subject of study during the most recent granting period.

  20. Advanced Experiments in Nuclear Science, Volume I: Advanced Nuclear Physics and Chemistry Experiments.

    ERIC Educational Resources Information Center

    Duggan, Jerome L.; And Others

    The experiments in this manual represent state-of-the-art techniques which should be within the budgetary constraints of a college physics or chemistry department. There are fourteen experiments divided into five modules. The modules are on X-ray fluorescence, charged particle detection, neutron activation analysis, X-ray attenuation, and…

  1. Introduction to Homogenous Catalysis with Ruthenium-Catalyzed Oxidation of Alcohols: An Experiment for Undergraduate Advanced Inorganic Chemistry Students

    ERIC Educational Resources Information Center

    Miecznikowski, John R.; Caradonna, John P.; Foley, Kathleen M.; Kwiecien, Daniel J.; Lisi, George P.; Martinez, Anthony M.

    2011-01-01

    A three-week laboratory experiment, which introduces students in an advanced inorganic chemistry course to air-sensitive chemistry and catalysis, is described. During the first week, the students synthesize RuCl[subscript 2](PPh[subscript 3])[subscript 3]. During the second and third weeks, the students characterize the formed coordination…

  2. Advancing Chemistry with the Lanthanide and Actinide Elements Final Report, September 2013

    SciTech Connect

    Evans, William John

    2013-09-11

    The objective of this research is to use the unique chemistry available from complexes of the lanthanides and actinides, as well as related heavy metals such as scandium, yttrium, and bismuth to advance chemistry in energy-related areas. The lanthanides and actinides have a combination of properties in terms of size, charge, electropositive character, and f valence orbitals that provides special opportunities to probe reactivity and catalysis in ways not possible with the other metals in the periodic table. We seek to discover reaction pathways and structural types that reveal new options in reaction chemistry related to energy. Identification of new paradigms in structure and reactivity should stimulate efforts to develop new types of catalytic processes that at present are not under consideration because either the transformation or the necessary intermediates are unknown. This project is one half of my laboratory’s DOE research which was split 50:50 between Catalysis and Heavy Element Chemistry programs in 2010. Hence, this report is for a half-project.

  3. Recent Advances in the Chemistry and Biology of Naturally Occurring Antibiotics

    PubMed Central

    Chen, Jason S.; Edmonds, David J.; Estrada, Anthony A.

    2009-01-01

    Lead-in Ever since the world-shaping discovery of penicillin, nature’s molecular diversity has been extensively screened for new medications and lead compounds in drug discovery. The search for anti-infective agents intended to combat infectious diseases has been of particular interest and has enjoyed a high degree of success. Indeed, the history of antibiotics is marked with impressive discoveries and drug development stories, the overwhelming majority of which have their origins in nature. Chemistry, and in particular chemical synthesis, has played a major role in bringing naturally occurring antibiotics and their derivatives to the clinic, and no doubt these disciplines will continue to be key enabling technologies for future developments in the field. In this review article, we highlight a number of recent discoveries and advances in the chemistry, biology, and medicine of naturally occurring antibiotics, with particular emphasis on the total synthesis, analog design, and biological evaluation of molecules with novel mechanisms of action. PMID:19130444

  4. Advances in methods and algorithms in a modern quantum chemistry program package.

    PubMed

    Shao, Yihan; Molnar, Laszlo Fusti; Jung, Yousung; Kussmann, Jörg; Ochsenfeld, Christian; Brown, Shawn T; Gilbert, Andrew T B; Slipchenko, Lyudmila V; Levchenko, Sergey V; O'Neill, Darragh P; DiStasio, Robert A; Lochan, Rohini C; Wang, Tao; Beran, Gregory J O; Besley, Nicholas A; Herbert, John M; Lin, Ching Yeh; Van Voorhis, Troy; Chien, Siu Hung; Sodt, Alex; Steele, Ryan P; Rassolov, Vitaly A; Maslen, Paul E; Korambath, Prakashan P; Adamson, Ross D; Austin, Brian; Baker, Jon; Byrd, Edward F C; Dachsel, Holger; Doerksen, Robert J; Dreuw, Andreas; Dunietz, Barry D; Dutoi, Anthony D; Furlani, Thomas R; Gwaltney, Steven R; Heyden, Andreas; Hirata, So; Hsu, Chao-Ping; Kedziora, Gary; Khalliulin, Rustam Z; Klunzinger, Phil; Lee, Aaron M; Lee, Michael S; Liang, Wanzhen; Lotan, Itay; Nair, Nikhil; Peters, Baron; Proynov, Emil I; Pieniazek, Piotr A; Rhee, Young Min; Ritchie, Jim; Rosta, Edina; Sherrill, C David; Simmonett, Andrew C; Subotnik, Joseph E; Woodcock, H Lee; Zhang, Weimin; Bell, Alexis T; Chakraborty, Arup K; Chipman, Daniel M; Keil, Frerich J; Warshel, Arieh; Hehre, Warren J; Schaefer, Henry F; Kong, Jing; Krylov, Anna I; Gill, Peter M W; Head-Gordon, Martin

    2006-07-21

    Advances in theory and algorithms for electronic structure calculations must be incorporated into program packages to enable them to become routinely used by the broader chemical community. This work reviews advances made over the past five years or so that constitute the major improvements contained in a new release of the Q-Chem quantum chemistry package, together with illustrative timings and applications. Specific developments discussed include fast methods for density functional theory calculations, linear scaling evaluation of energies, NMR chemical shifts and electric properties, fast auxiliary basis function methods for correlated energies and gradients, equation-of-motion coupled cluster methods for ground and excited states, geminal wavefunctions, embedding methods and techniques for exploring potential energy surfaces. PMID:16902710

  5. A Study on Advanced Lithium-Based Battery Cell Chemistries to Enhance Lunar Exploration Missions

    NASA Technical Reports Server (NTRS)

    Reid, Concha; Bennett, William

    2009-01-01

    NASA's Exploration Technology Development Program (ETDP) Energy Storage Project conducted an advanced lithium-based battery chemistry feasibility study to determine the best advanced chemistry to develop for the Altair lunar lander and the Extravehicular Activities (EVA) advanced lunar surface spacesuit. These customers require safe, reliable energy storage systems with extremely high specific energy as compared to today's state-of-the-art batteries. Based on customer requirements, the specific energy goals for the development project are 220 watt-hours per kilogram (Wh/kg) delivered at the battery level at 0 degrees Celsius (degrees Celcius) at a C/10 discharge rate. Continuous discharge rates between C/5 and C/2, operation over 0 to 30 degrees C, and 200 cycles are targeted. The team, consisting of members from NASA Glenn Research Center, Johnson Space Center, and Jet Propulsion laboratory, surveyed the literature, compiled information on recent materials developments, and consulted with other battery experts in the community to identify advanced battery materials that might be capable of achieving the desired results with further development. A variety of electrode materials were considered, including layered metal oxides, spinel oxides, and olivine-type cathode materials, and lithium metal, lithium alloy, and silicon-based composite anode materials. lithium-sulfur systems were also considered. Hypothetical cell constructs that combined compatible anode and cathode materials with suitable electrolytes, separators, current collectors, headers, and cell enclosures were modeled. While some of these advanced materials are projected to obtain the desired electrical performance, there are risks that also factored into the decision making process. The risks include uncertainties due to issues such as safety of a system containing some of these materials, ease of scaling-up of large batches of raw materials, adaptability of the materials to processing using established

  6. Insights into the physical chemistry of materials from advances in HAADF-STEM

    SciTech Connect

    Sohlberg, Karl; Pennycook, Timothy J.; Zhou, Wu; Pennycook, Stephen J.

    2014-11-13

    The observation that, ‘‘New tools lead to new science’’[P. S. Weiss, ACS Nano., 2012, 6(3), 1877–1879], is perhaps nowhere more evident than in scanning transmission electron microscopy (STEM). Advances in STEM have endowed this technique with several powerful and complimentary capabilities. For example, the application of high-angle annular dark-field imaging has made possible real-space imaging at subangstrom resolution with Z-contrast (Z = atomic number). Further advances have wrought: simultaneous real-space imaging and elemental identification by using electron energy loss spectroscopy (EELS); 3-dimensional (3D) mapping by depth sectioning; monitoring of surface diffusion by time-sequencing of images; reduced electron energy imaging for probing graphenes; etc. In this paper we review how these advances, often coupled with first-principles theory, have led to interesting and important new insights into the physical chemistry of materials. We then review in detail a few specific applications that highlight some of these STEM capabilities.

  7. Insights into the physical chemistry of materials from advances in HAADF-STEM

    DOE PAGESBeta

    Sohlberg, Karl; Pennycook, Timothy J.; Zhou, Wu; Pennycook, Stephen J.

    2014-11-13

    The observation that, ‘‘New tools lead to new science’’[P. S. Weiss, ACS Nano., 2012, 6(3), 1877–1879], is perhaps nowhere more evident than in scanning transmission electron microscopy (STEM). Advances in STEM have endowed this technique with several powerful and complimentary capabilities. For example, the application of high-angle annular dark-field imaging has made possible real-space imaging at subangstrom resolution with Z-contrast (Z = atomic number). Further advances have wrought: simultaneous real-space imaging and elemental identification by using electron energy loss spectroscopy (EELS); 3-dimensional (3D) mapping by depth sectioning; monitoring of surface diffusion by time-sequencing of images; reduced electron energy imaging formore » probing graphenes; etc. In this paper we review how these advances, often coupled with first-principles theory, have led to interesting and important new insights into the physical chemistry of materials. We then review in detail a few specific applications that highlight some of these STEM capabilities.« less

  8. Semibullvalene and diazasemibullvalene: recent advances in the synthesis, reaction chemistry, and synthetic applications.

    PubMed

    Zhang, Shaoguang; Zhang, Wen-Xiong; Xi, Zhenfeng

    2015-07-21

    applications of NSBV. Several novel reaction patterns have been explored, including thermolysis, C-N bond insertion, rearrangement-cycloaddition, oxidation, and nucleophilic ring-opening reactions. Diverse and interesting N-containing polycyclic skeletons can be constructed, such as nickelaazetidine, 1,5-diazatriquinacenes, and triazabrexadienes, which are not available by other means. Our results show that NSBV not only features a rapid aza-Cope rearrangement with a low activation barrier but also acts as unique synthetic reagent that is significantly different from aziridine. The strained rigid ring systems as a whole can be involved in the reactions. Our achievements highlight two significant advances: (i) the well-established efficient synthesis and isolation of NSBV has greatly accelerated the development of NSBV chemistry, and (ii) the previously unattainable molecules have become "normal" and routine starting materials for the synthesis of otherwise unavailable but interesting structures. We expect that our pursuits will inspire and help direct future chemical and physical research on NSBV. PMID:26061608

  9. ENVIRONMENTAL CHEMISTRY

    EPA Science Inventory

    Environmental chemistry is applied to estimating the exposure of ecosystems and humans to various chemical environmental stressors. Among the stressors of concern are mercury, pesticides, and arsenic. Advanced analytical chemistry techniques are used to measure these stressors ...

  10. Using an Advanced Computational Laboratory Experiment to Extend and Deepen Physical Chemistry Students' Understanding of Atomic Structure

    ERIC Educational Resources Information Center

    Hoffman, Gary G.

    2015-01-01

    A computational laboratory experiment is described, which involves the advanced study of an atomic system. The students use concepts and techniques typically covered in a physical chemistry course but extend those concepts and techniques to more complex situations. The students get a chance to explore the study of atomic states and perform…

  11. An Advanced Analytical Chemistry Experiment Using Gas Chromatography-Mass Spectrometry, MATLAB, and Chemometrics to Predict Biodiesel Blend Percent Composition

    ERIC Educational Resources Information Center

    Pierce, Karisa M.; Schale, Stephen P.; Le, Trang M.; Larson, Joel C.

    2011-01-01

    We present a laboratory experiment for an advanced analytical chemistry course where we first focus on the chemometric technique partial least-squares (PLS) analysis applied to one-dimensional (1D) total-ion-current gas chromatography-mass spectrometry (GC-TIC) separations of biodiesel blends. Then, we focus on n-way PLS (n-PLS) applied to…

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

    SciTech Connect

    Charles Casey

    2011-08-20

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

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

    SciTech Connect

    Prof. Charles Casey, University of Wisconsin-Madison

    2011-08-20

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

  14. Development of new methods and polyphosphazene chemistries for advanced materials applications

    NASA Astrophysics Data System (ADS)

    Hindenlang, Mark D.

    The work described within this thesis focuses on the design, synthesis, and characterization of new phosphazenes with potential in advanced materials applications. Additionally, these unique polymers required the development of novel reaction methods or the investigation of new phosphazene chemistry to achieve their synthesis. Chapter 1 lays out some of the basic principles and fundamentals of polymer chemistry. Chapter 2 investigates the use of iodinated polyphosphazenes as x-ray opaque materials. Single-substituent polymers with 4-iodophenoxy or 4-iodophenylanaline ethyl ester units as the only side groups were prepared. Although a single-substitutent polymer with 3,5-diiodotyrosine ethyl ester groups was difficult to synthesize, probably because of steric hindrance, mixed-substituent polymers that contained the non-iodinated ethyl esters of glycyine, alanine, or phenylalanine plus a corresponding iodinated substituent, could be synthesized. Multinuclear NMR spectroscopy was used to follow the substitution of side groups onto the phosphazene back bone and judge the ratio of substituents. Chapter 3 details the initial investigation into 3,4-dihydroxy-L-phenylalanine ethyl ester and dopamine substituted polyphosphazenes that could be applied to a number of applications. L-DOPAEE was acetonide protected to prevent crosslinking reactions by the catechole functionality. Cyclic small molecule studies and macromolecular substitution reactions on the linear high polymer were conducted with the protected L-DOPA. Continuing studies into protection of the dopamine catechol have elucidated a viable method for the synthesis of amino-linked dopamine polymers. Chapter 4 describes a method for the synthesis of phosphazenes with quaternary amine complexes as potential antibacterial agents. Replacement reactions of pyridine alkoxides and chlorophosphazenes were first attempted at the small molecule level to study the reactivities of pyridine alkoxides. The formation of an

  15. Use of Protecting Groups in Carbohydrate Chemistry: An Advanced Organic Synthesis Experiment

    NASA Astrophysics Data System (ADS)

    Cunha, Anna C.; Pereira, Leticia O. R.; de Souza, Maria Cecília B. V.; Ferreira, Vitor F.

    1999-01-01

    A simple and inexpensive three-step reaction sequence for advanced experimental organic chemistry using D-glucosamine hydrochloride as starting material for the synthesis of 2-amino-2-deoxy-1,3,4,6-tetra-O-acetyl-b-D-glucopyranose hydrochloride is described. D-Glucosamine hydrochloride is a carbohydrate derivative isolated from crab shells. It is inexpensive and readily available from most chemical companies. This reaction sequence is appropriate for teaching undergraduate students the correct use of protecting groups. This is a major concept in organic synthesis and one of the determinant factors in the successful realization of multiple-step synthetic projects. The aim of the experiment is to protect the hydroxyl groups of D-glucosamine leaving its amino group as hydrochloride salt. The experiment deals only with protection and deprotection reactions. All products are crystalline substances. The amino group of d-glucosamine hydrochloride is protected by a condensation reaction with p-methoxybenzaldehyde to produce the Schiff's base as a mixture of a- and b-anomers. The second step involves the protection of all hydroxyl groups by esterification reaction using acetic anhydride, forming the imino-tetraacetate derivative as the b-anomer. The stereospecificity of this reaction at the anomeric center is due to the voluminous imino group at C-2. Removal of the amino protection group of this derivative is the final step, which can be accomplished by a selective acid hydrolysis affording the desired peracylated D-glucosamine hydrochloride.

  16. Integrating Project-Based Service-Learning into an Advanced Environmental Chemistry Course

    NASA Astrophysics Data System (ADS)

    Draper, Alison J.

    2004-02-01

    In an advanced environmental chemistry course, the inclusion of semester-long scientific service projects successfully integrated the research process with course content. Each project involved a unique community-based environmental analysis in which students assessed an aspect of environmental health. The projects were due in small pieces at even intervals, and students worked independently or in pairs. Initially, students wrote a project proposal in which they chose and justified a project. Following a literature review of their topic, they drafted sampling and analysis plans using methods in the literature. Samples were collected and analyzed, and all students assembled scientific posters describing the results of their study. In the last week of the semester, the class traveled to a regional professional meeting to present the posters. In all, students found the experience valuable. They learned to be professional environmental chemists and learned the value of the discipline to community health. Students not only learned about their own project in depth, but they were inspired to learn textbook material, not for an exam, but because it helped them understand their own project. Finally, having a community to answer to at the end of the project motivated students to do careful work.

  17. Advances in molecular quantum chemistry contained in the Q-Chem 4 program package

    NASA Astrophysics Data System (ADS)

    Shao, Yihan; Gan, Zhengting; Epifanovsky, Evgeny; Gilbert, Andrew T. B.; Wormit, Michael; Kussmann, Joerg; Lange, Adrian W.; Behn, Andrew; Deng, Jia; Feng, Xintian; Ghosh, Debashree; Goldey, Matthew; Horn, Paul R.; Jacobson, Leif D.; Kaliman, Ilya; Khaliullin, Rustam Z.; Kuś, Tomasz; Landau, Arie; Liu, Jie; Proynov, Emil I.; Rhee, Young Min; Richard, Ryan M.; Rohrdanz, Mary A.; Steele, Ryan P.; Sundstrom, Eric J.; Woodcock, H. Lee, III; Zimmerman, Paul M.; Zuev, Dmitry; Albrecht, Ben; Alguire, Ethan; Austin, Brian; Beran, Gregory J. O.; Bernard, Yves A.; Berquist, Eric; Brandhorst, Kai; Bravaya, Ksenia B.; Brown, Shawn T.; Casanova, David; Chang, Chun-Min; Chen, Yunqing; Chien, Siu Hung; Closser, Kristina D.; Crittenden, Deborah L.; Diedenhofen, Michael; DiStasio, Robert A., Jr.; Do, Hainam; Dutoi, Anthony D.; Edgar, Richard G.; Fatehi, Shervin; Fusti-Molnar, Laszlo; Ghysels, An; Golubeva-Zadorozhnaya, Anna; Gomes, Joseph; Hanson-Heine, Magnus W. D.; Harbach, Philipp H. P.; Hauser, Andreas W.; Hohenstein, Edward G.; Holden, Zachary C.; Jagau, Thomas-C.; Ji, Hyunjun; Kaduk, Benjamin; Khistyaev, Kirill; Kim, Jaehoon; Kim, Jihan; King, Rollin A.; Klunzinger, Phil; Kosenkov, Dmytro; Kowalczyk, Tim; Krauter, Caroline M.; Lao, Ka Un; Laurent, Adèle D.; Lawler, Keith V.; Levchenko, Sergey V.; Lin, Ching Yeh; Liu, Fenglai; Livshits, Ester; Lochan, Rohini C.; Luenser, Arne; Manohar, Prashant; Manzer, Samuel F.; Mao, Shan-Ping; Mardirossian, Narbe; Marenich, Aleksandr V.; Maurer, Simon A.; Mayhall, Nicholas J.; Neuscamman, Eric; Oana, C. Melania; Olivares-Amaya, Roberto; O'Neill, Darragh P.; Parkhill, John A.; Perrine, Trilisa M.; Peverati, Roberto; Prociuk, Alexander; Rehn, Dirk R.; Rosta, Edina; Russ, Nicholas J.; Sharada, Shaama M.; Sharma, Sandeep; Small, David W.; Sodt, Alexander; Stein, Tamar; Stück, David; Su, Yu-Chuan; Thom, Alex J. W.; Tsuchimochi, Takashi; Vanovschi, Vitalii; Vogt, Leslie; Vydrov, Oleg; Wang, Tao; Watson, Mark A.; Wenzel, Jan; White, Alec; Williams, Christopher F.; Yang, Jun; Yeganeh, Sina; Yost, Shane R.; You, Zhi-Qiang; Zhang, Igor Ying; Zhang, Xing; Zhao, Yan; Brooks, Bernard R.; Chan, Garnet K. L.; Chipman, Daniel M.; Cramer, Christopher J.; Goddard, William A., III; Gordon, Mark S.; Hehre, Warren J.; Klamt, Andreas; Schaefer, Henry F., III; Schmidt, Michael W.; Sherrill, C. David; Truhlar, Donald G.; Warshel, Arieh; Xu, Xin; Aspuru-Guzik, Alán; Baer, Roi; Bell, Alexis T.; Besley, Nicholas A.; Chai, Jeng-Da; Dreuw, Andreas; Dunietz, Barry D.; Furlani, Thomas R.; Gwaltney, Steven R.; Hsu, Chao-Ping; Jung, Yousung; Kong, Jing; Lambrecht, Daniel S.; Liang, WanZhen; Ochsenfeld, Christian; Rassolov, Vitaly A.; Slipchenko, Lyudmila V.; Subotnik, Joseph E.; Van Voorhis, Troy; Herbert, John M.; Krylov, Anna I.; Gill, Peter M. W.; Head-Gordon, Martin

    2015-01-01

    A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided, covering approximately the last seven years. These include developments in density functional theory methods and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces. In addition, a selection of example case studies that illustrate these capabilities is given. These include extensive benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Møller-Plesset (MP2) methods for intermolecular interactions, a variety of parallel performance benchmarks, and tests of the accuracy of implicit solvation models. Some specific chemical examples include calculations on the strongly correlated Cr2 dimer, exploring zeolite-catalysed ethane dehydrogenation, energy decomposition analysis of a charged ter-molecular complex arising from glycerol photoionisation, and natural transition orbitals for a Frenkel exciton state in a nine-unit model of a self-assembling nanotube.

  18. Surface chemistry improvement of 100mm GaSb for advanced space based applications

    NASA Astrophysics Data System (ADS)

    Allen, L. P.; Flint, J. P.; Meshew, G.; Trevethan, J.; Furlong, M. J.; Martinez, B.; Mobray, A.

    2012-01-01

    As size requirements and pixel viabilities for infrared focal plane arrays (IRFPAs) continue to increase, resolution and sensitivity requirements for high performance advanced imaging systems must meet or surpass stringent demands. Strain layer superlattice (SLS) grown by molecular beam epitaxy (MBE) on 100mm GaSb has necessitated changes in crystal processing and finishing parameters. Device layer growth typically requires a thin (2-5 nm) and highly desorbable surface oxide on very flat substrates for successful MBE. This study compares the ability for rapid pre-epi desoprtion of three different chemo-mechanical (CMP) finishes on 100mm n:GaSb: CMP-1 with sequential double side polished (DSP), CMP-2 with sequential DSP, and CMP-2 with simultaneous double side polished (S-DSP). X-ray photoelectron spectroscopy (XPS) reveals the improvement from a CMP-1 (Ga-oxide rich) to CMP-2 (Sb-oxide rich) surface. No difference in surface chemistry was found between the CMP-2 of the sequential vs. simultaneous DSP. Tropel flatness measurements of the 100mm n:GaSb substrates show that both DSP and SDSP substrate batches yield excellent (<5μm) wafer warp. However, initial studies have shown a more consistent wafer flatness with use of the simultaneous-DSP process. MBE growth on the Sb-rich surface was examined by high resolution XRD and resulted in a 64.7A periodicity and excellent FWHM (~20 arcsec) which verified the GaSb surface finish effectiveness. The resultant surface finish and flatness may provide a benefit for larger diameter GaSb IRFPA applications.

  19. Recent advances in the application of electron tomography to materials chemistry.

    PubMed

    Leary, Rowan; Midgley, Paul A; Thomas, John Meurig

    2012-10-16

    Nowadays, tomography plays a central role in pureand applied science, in medicine, and in many branches of engineering and technology. It entails reconstructing the three-dimensional (3D) structure of an object from a tilt series of two-dimensional (2D) images. Its origin goes back to 1917, when Radon showed mathematically how a series of 2D projection images could be converted to the 3D structural one. Tomographic X-ray and positron scanning for 3D medical imaging, with a resolution of ∼1 mm, is now ubiquitous in major hospitals. Electron tomography, a relatively new chemical tool, with a resolution of ∼1 nm, has been recently adopted by materials chemists as an invaluable aid for the 3D study of the morphologies, spatially-discriminating chemical compositions, and defect properties of nanostructured materials. In this Account, we review the advances that have been made in facilitating the recording of the required series of 2D electron microscopic images and the subsequent process of 3D reconstruction of specimens that are vulnerable, to a greater or lesser degree, to electron beam damage. We describe how high-fidelity 3D tomograms may be obtained from relatively few 2D images by incorporating prior structural knowledge into the reconstruction process. In particular, we highlight the vital role of compressed sensing, a recently developed procedure well-known to information theorists that exploits ideas of image compression and "sparsity" (that the important image information can be captured in a reduced data set). We also touch upon another promising approach, "discrete" tomography, which builds into the reconstruction process a prior assumption that the object can be described in discrete terms, such as the number of constituent materials and their expected densities. Other advances made recently that we outline, such as the availability of aberration-corrected electron microscopes, electron wavelength monochromators, and sophisticated specimen goniometers

  20. Bridging the Cognitive-Affective Gaps: Teaching Chemistry while Advancing Affective Objectives. The Singapore Curricular Experience

    ERIC Educational Resources Information Center

    Tan, Kok Siang; Goh, Ngoh Khang; Chia, Lian Sai

    2006-01-01

    Chemistry teachers face constraints when trying to integrate cognitive and affective objectives, and hence thoughtful lesson planning is required to achieve the goal. Chemistry teachers can educate students to be knowledgeable about chemical concepts, processes and the benefits of responsible practice by the chemical industry, while being aware,…

  1. Filling a Plastic Bag with Carbon Dioxide: A Student-Designed Guided-Inquiry Lab for Advanced Placement and College Chemistry Courses

    ERIC Educational Resources Information Center

    Lanni, Laura M.

    2014-01-01

    A guided-inquiry lab, suitable for first-year general chemistry or high school advanced placement chemistry, is presented that uses only inexpensive, store-bought materials. The reaction of sodium bicarbonate (baking soda) with aqueous acetic acid (vinegar), under the constraint of the challenge to completely fill a sealable plastic bag with the…

  2. Application of Advances in Learning Theory and Philosophy of Science to the Improvement of Chemistry Teaching.

    ERIC Educational Resources Information Center

    Novak, Joseph D.

    1984-01-01

    Discusses seven key concepts in Ausubel's learning theory which function to guide research and teaching. Also discusses concept mapping and Gowins Vee, providing examples of how they are used in chemistry instruction. (JN)

  3. Role of Water in Electron-Initiated Processes and Radical Chemistry: Issues and Scientific Advances

    SciTech Connect

    Garrett, Bruce C.; Dixon, David A.; Camaioni, Donald M.; Chipman, Daniel M.; Johnson, Mark A.; Jonah, Charles D.; Kimmel, Greg A.; Miller, John H.; Rescigno, Tom; Rossky, Peter J.; Xantheas, Sotiris S.; Colson, Steve D.; Laufer, Allan H.; Ray, Douglas; Barbara, Paul F.; Bartels, David M.; Bowen, Kit H.; Becker, Kurt H.; Bradforth, Stephen E.; Carmichael, Ian; Coe, James V.; Corrales, L. Rene; Cowin, James P.; Dupuis, Michel; Eisenthal, Kenneth B.; Franz, James A.; Gutowski, Maciej S.; Jordon, Kenneth D.; Kay, Bruce D.; La Verne, Jay A.; Lymar, Sergei V.; Madey, Theodore E.; Mccurdy, C. W.; Meisel, Dan; Mukamel, Shaul; Nilsson, Anders R.; Orlando, Thomas M.; Petrik, Nikolay G.; Pimblott, Simon M.; Rustad, James R.; Schenter, Gregory K.; Singer, Sherwin J.; Tokmakoff, Andrei; Wang, Lai-Sheng; Wittig, Curt; Zwier, Timothy S.

    2005-01-12

    An understanding of electron-initiated processes in aqueous systems and the subsequent radical chemistry these processes induce is significant in such diverse fields as waste remediation and environmental cleanup, radiation processing, nuclear reactors, and medical diagnosis and therapy. We review the state of the art in the physical chemistry and chemical physics of electron-initiated processes in aqueous systems and raise critical research issues and fundamental questions that remain unanswered.

  4. Free Radical Reactions in Aqueous Solutions: Examples from Advanced Oxidation Processes for Wastewater from the Chemistry in Airborne Water Droplets

    NASA Astrophysics Data System (ADS)

    Baird, N. Colin

    1997-07-01

    Inorganic chemistry involving free radicals in aqueous solutions can be important in environmental processes. A common free radical reaction in aqueous solution is electron transfer, especially to the hydroxyl radical and to ozone. Hydrogen peroxide and free radicals related to it act as weak acids, so both their neutral and deprotonated forms must be considered in reactions. In Advanced Oxidation Processes, the hydroxyl radical concentration in water is greatly increased by reactions involving ozone and/or ultraviolet light. Irradiation of solid titanium dioxide can also be used to generate the radicals. The hydroxyl radicals are used in the Processes to initiate the oxidation of dissolved organic pollutants. Free radical reactions also play an important role in the chemistry of water droplets suspended in air in clouds and fogs. The radicals arise indirectly from the photoionization of dissolved organic compounds such as aldehydes and from the iron-catalyzed decomposition of dissolved hydrogen peroxide. They oxidize dissolved sulfur dioxide and certain organic compounds.

  5. Advanced modelling of the multiphase DMS chemistry with the CAPRAM DMS module 1.0

    NASA Astrophysics Data System (ADS)

    Hoffmann, Erik Hans; Tilgner, Andreas; Schrödner, Roland; Wolke, Ralf; Herrmann, Hartmut

    2016-04-01

    Oceans are the general emitter of dimethyl sulphide (DMS), the major natural sulphur source (Andreae, 1990), and cover approximately 70 % of earth's surface. The main DMS oxidation products are SO2, H2SO4 and methyl sulfonic acid (MSA). Hence, DMS is very important for formation of non-sea salt sulphate (nss SO42-) aerosols and secondary particulate matter and thus global climate. Despite many previous model studies, there are still important knowledge gaps, especially in aqueous phase DMS chemistry, of its atmospheric fate (Barnes et al., 2006). Therefore, a comprehensive multiphase DMS chemistry mechanism, the CAPRAM DMS module 1.0 (DM1.0), has been developed. The DM1.0 includes 103 gas phase reactions, 5 phase transfers and 54 aqueous phase reactions. It was coupled with the multiphase chemistry mechanism MCMv3.2/CAPRAM4.0α (Rickard et al., 2015; Bräuer et al., 2016) and the extended CAPRAM halogen module 2.1 (HM2.1, Bräuer et al., 2013) for investigation of multiphase DMS oxidation in the marine boundary layer. Then, a pristine ocean scenario was simulated using the air parcel model SPACCIM (Wolke et al., 2005) including 8 non-permanent cloud passages - 4 at noon and 4 at midnight. This allows the investigation of the influence of deliquesced particles and clouds on multiphase DMS chemistry during both daytime and nighttime conditions as well as under cloud formation and evaporation. To test the influence of various subsystems on multiphase DMS chemistry different sensitivity runs were performed. Investigations of multiphase chemistry of DMS and its important oxidation products were done using concentration-time profiles and detailed time-resolved reaction flux analyses. The model studies revealed the importance of aqueous phase chemistry for DMS and its oxidation products. Overall about 7.0% of DMS is effectively oxidised by O3 in the aqueous phase of clouds. The simulations revealed the importance of halogen and aqueous phase chemistry for DMS and its

  6. On the physics, chemistry and toxicology of ultrafine anthropogenic, atmospheric aerosols (UAAA): new advances.

    PubMed

    Spurny, K R

    1998-08-01

    The existing data about the epidemiology, toxicology, physics and chemistry of atmospheric particulate pollutants were recently essentially completed and extended. They do support the hypothesis that the fine and very fine dispersed fraction of the atmospheric anthropogenic aerosols (UAAA) are responsible for the aggravation of the health risk potential of the polluted atmosphere during the last decade. The recently published data dealing primarily with the physics, chemistry, sampling and analysis of these highly dispersed particulate air pollutants are reviewed, summarized and critically evaluated. PMID:9820675

  7. Recent Advances in chemistry and pharmacology of 2-methoxyestradiol: An anticancer investigational drug.

    PubMed

    Kumar, B Sathish; Raghuvanshi, Dushyant Singh; Hasanain, Mohammad; Alam, Sarfaraz; Sarkar, Jayanta; Mitra, Kalyan; Khan, Feroz; Negi, Arvind S

    2016-06-01

    2-Methoxyestradiol (2ME2), an estrogen hormone metabolite is a potential cancer chemotherapeutic agent. Presently, it is an investigational drug under various phases of clinical trials alone or in combination therapy. Its anticancer activity has been attributed to its antitubulin, antiangiogenic, pro-apoptotic and ROS induction properties. This anticancer drug candidate has been explored extensively in last twenty years for its detailed chemistry and pharmacology. Present review is an update of its chemistry and biological activity. It also extends an assessment of potential of 2ME2 and its analogues as possible anticancer drug in future. PMID:27020471

  8. Green Oxidation of Menthol Enantiomers and Analysis by Circular Dichroism Spectroscopy: An Advanced Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Geiger, H. Cristina; Donohoe, James S.

    2012-01-01

    Green chemistry addresses environmental concerns associated with chemical processes and increases awareness of possible harmful effects of chemical reagents. Efficient reactions that eliminate or reduce the use of organic solvents or toxic reagents are increasingly available. A two-week experiment is reported that entails the calcium hypochlorite…

  9. Advanced Chemistry for Operators. Training Module 1.321.3.77.

    ERIC Educational Resources Information Center

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with inorganic and general organic chemistry as applied to water and wastewater treatment. Included are objectives, instructor guides, and student handouts. The module contains material related to chemical reactions in water solutions,…

  10. Exploring Interactive and Dynamic Simulations Using a Computer Algebra System in an Advanced Placement Chemistry Course

    ERIC Educational Resources Information Center

    Matsumoto, Paul S.

    2014-01-01

    The article describes the use of Mathematica, a computer algebra system (CAS), in a high school chemistry course. Mathematica was used to generate a graph, where a slider controls the value of parameter(s) in the equation; thus, students can visualize the effect of the parameter(s) on the behavior of the system. Also, Mathematica can show the…

  11. Green, Enzymatic Syntheses of Divanillin and Diapocynin for the Organic, Biochemistry, or Advanced General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Nishimura, Rachel T.; Giammanco, Chiara H.; Vosburg, David A.

    2010-01-01

    Environmentally benign chemistry is an increasingly important topic both in the classroom and the laboratory. In this experiment, students synthesize divanillin from vanillin or diapocynin from apocynin, using horseradish peroxidase and hydrogen peroxide in water. The dimerized products form rapidly at ambient temperature and are isolated by…

  12. Supramolecular Chemistry and Mechanochemistry of Macromolecules: Recent Advances by Single-Molecule Force Spectroscopy.

    PubMed

    Cheng, Bo; Cui, Shuxun

    2015-01-01

    Atomic force spectroscopy (AFM)-based single-molecule force spectroscopy (SMFS) was invented in the 1990s. Since then, SMFS has been developed into a powerful tool to study the inter- and intra-molecular interactions of macromolecules. Using SMFS, a number of problems in the field of supramolecular chemistry and mechanochemistry have been studied at the single-molecule level, which are not accessible by traditional ensemble characterization methods. In this review, the principles of SMFS are introduced, followed by the discussion of several problems of contemporary interest at the interface of supramolecular chemistry and mechanochemistry of macromolecules, including single-chain elasticity of macromolecules, interactions between water and macromolecules, interactions between macromolecules and solid surface, and the interactions in supramolecular polymers. PMID:25860255

  13. Recent advances in crosslinking chemistry of biomimetic poly(ethylene glycol) hydrogels

    PubMed Central

    Lin, Chien-Chi

    2015-01-01

    The design and application of biomimetic hydrogels have become an important and integral part of modern tissue engineering and regenerative medicine. Many of these hydrogels are prepared from synthetic macromers (e.g., poly(ethylene glycol) or PEG) as they provide high degrees of tunability for matrix crosslinking, degradation, and modification. For a hydrogel to be considered biomimetic, it has to recapitulate key features that are found in the native extracellular matrix, such as the appropriate matrix mechanics and permeability, the ability to sequester and deliver drugs, proteins, and or nucleic acids, as well as the ability to provide receptor-mediated cell-matrix interactions and protease-mediated matrix cleavage. A variety of chemistries have been employed to impart these biomimetic features into hydrogel crosslinking. These chemistries, such as radical-mediated polymerizations, enzyme-mediated crosslinking, bio-orthogonal click reactions, and supramolecular assembly, may be different in their crosslinking mechanisms but are required to be efficient for gel crosslinking and ligand bioconjugation under aqueous reaction conditions. The prepared biomimetic hydrogels should display a diverse array of functionalities and should also be cytocompatible for in vitro cell culture and/or in situ cell encapsulation. The focus of this article is to review recent progress in the crosslinking chemistries of biomimetic hydrogels with a special emphasis on hydrogels crosslinked from poly(ethylene glycol)-based macromers. PMID:26029357

  14. Recent advances in the chemistry of Rh carbenoids: multicomponent reactions of diazocarbonyl compounds

    NASA Astrophysics Data System (ADS)

    Medvedev, J. J.; Nikolaev, V. A.

    2015-07-01

    Multicomponent reactions of diazo compounds catalyzed by RhII complexes become a powerful tool for organic synthesis. They enable three- or four-step processes to be carried out as one-pot procedures (actually as one step) with high stereoselectivity to give complex organic molecules, including biologically active compounds. This review addresses recent results in the chemistry of Rh-catalyzed multicomponent reactions of diazocarbonyl compounds with the intermediate formation of N-, O- and C=O-ylides. The diastereo- and enantioselectivity of these reactions and the possibility of using various co-catalysts to increase the efficiency of the processes under consideration are discussed. The bibliography includes 120 references.

  15. Advances in nanoscale alloys and intermetallics: low temperature solution chemistry synthesis and application in catalysis.

    PubMed

    Jana, Subhra

    2015-11-21

    Based on the bottom-up chemistry techniques, the size, shape, and composition controlled synthesis of nanoparticles can now be achieved uniformly, which is of great importance to the nanoscience community as well as in modern catalysis research. The low-temperature solution-phase synthesis approach represents one of the most attractive strategies and has been utilized to synthesize nanoscale metals, alloys and intermetallics, including a number of new metastable phases. This perspective will highlight the solution-based nanoparticle synthesis techniques, a low-temperature platform, for the synthesis of size and shape-tunable nanoscale transition metals, alloys, and intermetallics from the literature, keeping a focus on the utility of these nanomaterials in understanding the catalysis. For each solution-based nanoparticle synthesis technique, a comprehensive overview has been given for the reported nanoscale metals, alloys, and intermetallics, followed by critical comments. Finally, their enhanced catalytic activity and durability as novel catalysts have been discussed towards several hydrogenation/dehydrogenation reactions and also for different inorganic to organic reactions. Hence, the captivating advantages of this controllable low-temperature solution chemistry approach have several important implications and together with them this approach provides a promising route to the development of next-generation nanostructured metals, alloys, and intermetallics since they possess fascinating properties as well as outstanding catalytic activity. PMID:26477400

  16. Free Radical Addition Polymerization Kinetics without Steady-State Approximations: A Numerical Analysis for the Polymer, Physical, or Advanced Organic Chemistry Course

    ERIC Educational Resources Information Center

    Iler, H. Darrell; Brown, Amber; Landis, Amanda; Schimke, Greg; Peters, George

    2014-01-01

    A numerical analysis of the free radical addition polymerization system is described that provides those teaching polymer, physical, or advanced organic chemistry courses the opportunity to introduce students to numerical methods in the context of a simple but mathematically stiff chemical kinetic system. Numerical analysis can lead students to an…

  17. Advancing the Chemistry of CuWO4 for Photoelectrochemical Water Oxidation.

    PubMed

    Lhermitte, Charles R; Bartlett, Bart M

    2016-06-21

    Photoelectrochemical (PEC) cells are an ongoing area of exploration that provide a means of converting solar energy into a storable chemical form (molecular bonds). In particular, using PEC cells to drive the water splitting reaction to obtain H2 could provide a clean and sustainable route to convert solar energy into chemical fuels. Since the discovery of catalytic water splitting on TiO2 photoelectrodes by Fujishima and Honda, significant efforts have been directed toward developing high efficiency metal oxides to use as photocatalysts for this reaction. Improving the efficiency of PEC cells requires developing chemically stable, and highly catalytic anodes for the oxygen-evolution reaction (OER). This water oxidation half reaction requires four protons and four electrons coupling in two bond making steps to form O2, which limits the rate. Our group has accelerated efforts in CuWO4 as a candidate for PEC OER chemistry. Its small band gap of 2.3 eV allows for using visible light to drive OER, and the reaction proceeds with a high degree of chemoselectivity, even in the presence of more kinetically accessible anions such as chloride, which is common to seawater. Furthermore, CuWO4 is a chemically robust material when subjected to the highly oxidizing conditions of PEC OER. The next steps for accelerating research using this (and other), ternary phase oxides, is to move beyond reporting the basic PEC measurements to understanding fundamental chemical reaction mechanisms operative during OER on semiconductor surfaces. In this Account, we outline the process for PEC OER on CuWO4 thin films with emphasis on the chemistry of this reaction, the reaction rate and selectivity (determined by controlled-potential coulometry and oxygen-detection experiments). We discuss key challenges with CuWO4 such as slow kinetics and the presence of an OER-mediating mid-gap state, probed by electrochemical impedance spectroscopy. We propose that this mid-gap state imparts the observed

  18. Exploring Atmospheric Aerosol Chemistry with Advanced High-Resolution Mass Spectrometry and Particle Imaging Methods

    NASA Astrophysics Data System (ADS)

    Nizkorodov, S.

    2014-12-01

    Physical and chemical complexity of atmospheric aerosols presents significant challenges both to experimentalists working on aerosol characterization and to modelers trying to parameterize critical aerosol properties. Multi-modal approaches that combine state-of-the-art experimental, theoretical, and modeling methods are becoming increasingly important in aerosol research. This presentation will discuss recent applications of unique high-resolution mass spectrometry and particle imaging tools developed at two Department of Energy's user facilities, the Environmental Molecular Science Laboratory (EMSL) and Advanced Light Source (ALS), to studies of molecular composition, photochemical aging, and properties of laboratory-generated and field aerosols. Specifically, this presentation will attempt to address the following questions: (a) how do NO2, SO2, and NH3 affect molecular level composition of anthropogenic aerosols?; (b) what factors determine viscosity/surface tension of organic aerosol particles?; (c) how does photolysis affect molecular composition and optical properties of organic aerosols?

  19. Stratospheric chemistry

    SciTech Connect

    Brune, W.H. )

    1991-01-01

    Advances in stratospheric chemistry made by investigators in the United States from 1987 to 1990 are reviewed. Subject areas under consideration include photochemistry of the polar stratosphere, photochemistry of the global stratosphere, and assessments of inadvertent modification of the stratosphere by anthropogenic activity. Particular attention is given to early observations and theories, gas phase chemistry, Antarctic observations, Arctic observations, odd-oxygen, odd-hydrogen, odd-nitrogen, halogens, aerosols, modeling of stratospheric ozone, and reactive nitrogen effects.

  20. Review of old chemistry and new catalytic advances in the on-purpose synthesis of butadiene.

    PubMed

    Makshina, Ekaterina V; Dusselier, Michiel; Janssens, Wout; Degrève, Jan; Jacobs, Pierre A; Sels, Bert F

    2014-11-21

    Increasing demand for renewable feedstock-based chemicals is driving the interest of both academic and industrial research to substitute petrochemicals with renewable chemicals from biomass-derived resources. The search towards novel platform chemicals is challenging and rewarding, but the main research activities are concentrated on finding efficient pathways to produce familiar drop-in chemicals and polymer building blocks. A diversity of industrially important monomers like alkenes, conjugated dienes, unsaturated carboxylic acids and aromatic compounds are thus targeted from renewable feedstock. In this context, on-purpose production of 1,3-butadiene from biomass-derived feedstock is an interesting example as its production is under pressure by uncertainty of the conventional fossil feedstock. Ethanol, obtained via fermentation or (biomass-generated) syngas, can be converted to butadiene, although there is no large commercial activity today. Though practised on a large scale in the beginning of the 20th century, there is a growing worldwide renewed interest in the butadiene-from-ethanol route. An alternative route to produce butadiene from biomass is through direct carbohydrate and gas fermentation or indirectly via the dehydration of butanediols. This review starts with a brief discussion on the different feedstock possibilities to produce butadiene, followed by a comprehensive summary of the current state of knowledge regarding advances and achievements in the field of the chemocatalytic conversion of ethanol and butanediols to butadiene, including thermodynamics and kinetic aspects of the reactions with discussions on the reaction pathways and the type of catalysts developed. PMID:24993100

  1. Development of Advanced In-Situ Techniques for Chemistry Monitoring and Corrosion Mitigation in SCWO Environments

    SciTech Connect

    Macdonald, D. D.; Lvov, S. N.

    2000-03-31

    This project is developing sensing technologies and corrosion monitoring techniques for use in super critical water oxidation (SCWO) systems to reduce the volume of mixed low-level nuclear waste by oxidizing organic components in a closed cycle system where CO2 and other gaseous oxides are produced, leaving the radioactive elements concentrated in ash. The technique uses water at supercritical temperatures under highly oxidized conditions by maintaining a high fugacity of molecular oxygen in the system, which causes high corrosion rates of even the most corrosive resistant reactor materials. This project significantly addresses the high corrosion shortcoming through development of (a) advanced electrodes and sensors for in situ potentiometric monitoring of pH in high subcritical and supercritical aqueous solutions, (b) an approach for evaluating the association constants for 1-1 aqueous electrolytes using a flow-through electrochemical thermocell; (c) an electrochemical noise sensor for the in situ measurement of corrosion rate in subcritical and supercritical aqueous systems; (d) a model for estimating the effect of pressure on reaction rates, including corrosion reactions, in high subcritical and supercritical aqueous systems. The project achieved all objectives, except for installing some of the sensors into a fully operating SCWO system.

  2. A Low-order Coupled Chemistry Meteorology Model for Testing Online and Offline Advanced Data Assimilation Schemes

    NASA Astrophysics Data System (ADS)

    Bocquet, M.; Haussaire, J. M.

    2015-12-01

    Bocquet and Sakov have recently introduced a low-order model based on the coupling of thechaotic Lorenz-95 model which simulates winds along a mid-latitude circle, with thetransport of a tracer species advected by this wind field. It has been used to testadvanced data assimilation methods with an online model that couples meteorology andtracer transport. In the present study, the tracer subsystem of the model is replacedwith a reduced photochemistry module meant to emulate reactive air pollution. Thiscoupled chemistry meteorology model, the L95-GRS model, mimics continental andtranscontinental transport and photochemistry of ozone, volatile organic compounds andnitrogen dioxides.The L95-GRS is specially useful in testing advanced data assimilation schemes, such as theiterative ensemble Kalman smoother (IEnKS) that combines the best of ensemble andvariational methods. The model provides useful insights prior to any implementation ofthe data assimilation method on larger models. For instance, online and offline dataassimilation strategies based on the ensemble Kalman filter or the IEnKS can easily beevaluated with it. It allows to document the impact of species concentration observationson the wind estimation. The model also illustrates a long standing issue in atmosphericchemistry forecasting: the impact of the wind chaotic dynamics and of the chemical speciesnon-chaotic but highly nonlinear dynamics on the selected data assimilation approach.

  3. African American Advanced Placement chemistry students and their developing study habits: A phenomenologically-based interpretive study

    NASA Astrophysics Data System (ADS)

    Rasmussen, Natalie D.

    The academic achievement gap between African American and White students has gained much attention in recent years. Much has been written about the causes of and reasons for this problem ranging from the vestigial effects of slavery to poor parenting. Much less has been written or understood about its solution. While it is impossible for educators to change the pasts of their African American students, it is possible to effect change for the few minutes in which they are in direct contact with them each day. If African American science students are taught effective study skills and habits, then perhaps they might have the tools to close the achievement gap themselves. The participants in this phenomenologically based interpretive study were five African American Advanced Placement Chemistry students from an inner-city high school. Three in-depth interviews were conducted with each of the participants during the beginning, middle and end of a semester. The purpose of the interviews was to locate the students in terms of their thought processes, experiences and perceived barriers concerning the nature and practice of effective study and retention of chemistry content. The interviews were recorded and transcribed. The texts were then analyzed for common themes. Five common themes emerged from the interviews. These were: (1) Homework vs. Study: a distinction between homework---which students knew how to approach; and study---which they did not. (2) Student Effort: their changing perception of adequate and effective study practices while in a rigorous course. (3) Teacher Rigor: they perceived high expectations and challenging work as a sign of respect from their teachers. (4) Parental Involvement: students' admission that they desired more input from parents regarding their academic performance. (5) Racial Considerations: their need to disprove negative stereotypes and their personal observations regarding racial differences in studying. A discussion of the themes and

  4. Science Update: Analytical Chemistry.

    ERIC Educational Resources Information Center

    Worthy, Ward

    1980-01-01

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

  5. Genetic algorithms and genetic programming for multiscale modeling: Applications in materials science and chemistry and advances in scalability

    NASA Astrophysics Data System (ADS)

    Sastry, Kumara Narasimha

    2007-03-01

    Effective and efficient rnultiscale modeling is essential to advance both the science and synthesis in a, wide array of fields such as physics, chemistry, materials science; biology, biotechnology and pharmacology. This study investigates the efficacy and potential of rising genetic algorithms for rnultiscale materials modeling and addresses some of the challenges involved in designing competent algorithms that solve hard problems quickly, reliably and accurately. In particular, this thesis demonstrates the use of genetic algorithms (GAs) and genetic programming (GP) in multiscale modeling with the help of two non-trivial case studies in materials science and chemistry. The first case study explores the utility of genetic programming (GP) in multi-timescaling alloy kinetics simulations. In essence, GP is used to bridge molecular dynamics and kinetic Monte Carlo methods to span orders-of-magnitude in simulation time. Specifically, GP is used to regress symbolically an inline barrier function from a limited set of molecular dynamics simulations to enable kinetic Monte Carlo that simulate seconds of real time. Results on a non-trivial example of vacancy-assisted migration on a surface of a face-centered cubic (fcc) Copper-Cobalt (CuxCo 1-x) alloy show that GP predicts all barriers with 0.1% error from calculations for less than 3% of active configurations, independent of type of potentials used to obtain the learning set of barriers via molecular dynamics. The resulting method enables 2--9 orders-of-magnitude increase in real-time dynamics simulations taking 4--7 orders-of-magnitude less CPU time. The second case study presents the application of multiobjective genetic algorithms (MOGAs) in multiscaling quantum chemistry simulations. Specifically, MOGAs are used to bridge high-level quantum chemistry and semiempirical methods to provide accurate representation of complex molecular excited-state and ground-state behavior. Results on ethylene and benzene---two common

  6. Development and Implementation of a Series of Laboratory Field Trips for Advanced High School Students to Connect Chemistry to Sustainability

    ERIC Educational Resources Information Center

    Aubrecht, Katherine B.; Padwa, Linda; Shen, Xiaoqi; Bazargan, Gloria

    2015-01-01

    We describe the content and organization of a series of day-long field trips to a university for high school students that connect chemistry content to issues of sustainability. The seven laboratory activities are in the areas of environmental degradation, energy production, and green chemistry. The laboratory procedures have been modified from…

  7. When Is a Molecule Three Dimensional? A Task-Specific Role for Imagistic Reasoning in Advanced Chemistry

    ERIC Educational Resources Information Center

    Stieff, Mike

    2011-01-01

    Imagistic reasoning appears to be a critical strategy for learning and problem solving in the sciences, particularly chemistry; however, little is known about how students use imagistic reasoning on genuine assessment tasks in chemistry. The present study employed a think-aloud protocol to explore when and how students use imagistic reasoning for…

  8. EPA Green Chemistry Advances

    EPA Science Inventory

    As an invited speaker, Dr. Leazer will deliver a plenary lecture and participate in a panel discussion at the 2013 AIChE National Meeting in San Francisco, CA. AIChE has embraced sustainability and is looking for guidance and leadership in building their sustainability program. ...

  9. Synthesis of a Partially Protected Azidodeoxy Sugar. A Project Suitable for the Advanced Undergraduate Organic Chemistry Laboratory

    NASA Astrophysics Data System (ADS)

    Norris, Peter; Freeze, Scott; Gabriel, Christopher J.

    2001-01-01

    The synthetic chemistry of carbohydrates provides a wealth of possible experiments for the undergraduate organic chemistry laboratory. However, few appropriate examples have been developed to date. With this simple two-step synthesis of a partially protected azidodeoxy sugar, we demonstrate several important concepts introduced in undergraduate chemistry (alcohol activation, steric hindrance, nucleophilic substitution) while offering products that are readily amenable to analysis by high field NMR. Students are exposed to techniques such as monitoring reactions by TLC, workup of reaction mixtures, and isolation by flash chromatography. Suitable methods for analysis of products include NMR, IR, MS, and polarimetry.

  10. Forster Resonance Energy Transfer and Conformational Stability of Proteins: An Advanced Biophysical Module for Physical Chemistry Students

    ERIC Educational Resources Information Center

    Sanchez, Katheryn M.; Schlamadinger, Diana E.; Gable, Jonathan E.; Kim, Judy E.

    2008-01-01

    Protein folding is an exploding area of research in biophysics and physical chemistry. Here, we describe the integration of several techniques, including absorption spectroscopy, fluorescence spectroscopy, and Forster resonance energy transfer (FRET) measurements, to probe important topics in protein folding. Cytochrome c is used as a model…

  11. Teaching Thermodynamics and Kinetics to Advanced General Chemistry Students and to Upper-Level Undergraduate Students Using PV Diagrams

    ERIC Educational Resources Information Center

    Iyengar, Srinivasan S.; deSouza, Romualdo T.

    2014-01-01

    We describe how complex concepts in macroscopic chemistry, namely, thermodynamics and kinetics, can be taught at considerable depth both at the first-year undergraduate as well as upper levels. We begin with a careful treatment of PV diagrams, and by pictorially integrating the appropriate area in a PV diagram, we introduce work. This starting…

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

    ERIC Educational Resources Information Center

    Swavey, Shawn

    2010-01-01

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

  13. Toward a New U.S. Chemicals Policy: Rebuilding the Foundation to Advance New Science, Green Chemistry, and Environmental Health

    PubMed Central

    Wilson, Michael P.; Schwarzman, Megan R.

    2009-01-01

    Objective We describe fundamental weaknesses in U.S. chemicals policy, present principles of chemicals policy reform, and articulate interdisciplinary research questions that should be addressed. With global chemical production projected to double over the next 24 years, federal policies that shape the priorities of the U.S. chemical enterprise will be a cornerstone of sustainability. To date, these policies have largely failed to adequately protect public health or the environment or motivate investment in or scientific exploration of cleaner chemical technologies, known collectively as green chemistry. On this trajectory, the United States will face growing health, environmental, and economic problems related to chemical exposures and pollution. Conclusions Existing policies have produced a U.S. chemicals market in which the safety of chemicals for human health and the environment is undervalued relative to chemical function, price, and performance. This market barrier to green chemistry is primarily a consequence of weaknesses in the Toxic Substances Control Act. These weaknesses have produced a chemical data gap, because producers are not required to investigate and disclose sufficient information on chemicals’ hazard traits to government, businesses that use chemicals, or the public; a safety gap, because government lacks the legal tools it needs to efficiently identify, prioritize, and take action to mitigate the potential health and environmental effects of hazardous chemicals; and a technology gap, because industry and government have invested only marginally in green chemistry research, development, and education. Policy reforms that close the three gaps—creating transparency and accountability in the market—are crucial for improving public and environmental health and reducing the barriers to green chemistry. The European Union’s REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulation has opened an opportunity for

  14. UCSD Geothermal Chemical Modeling Project: DOE Advanced Brine Chemistry Program. [University of California at San Diego (UCSD)

    SciTech Connect

    Moeller, N.; Weare, J.H.

    1992-04-01

    DOE funding to the UCSD Chemical Modeling Group supports research to provide computer models which will reliably characterize the equilibrium chemistry of geothermal brines (solution, solid and gas phases) under variable thermodynamic conditions. With this technology, it will be possible to rapidly and inexpensively predict the chemical behavior of geothermal brines during various resource recovery stages; exploration, production, plant energy extraction and rejection as well as in ancillary programs such as mineral recovery. Our modeling technology is based on recent progress in the physical chemistry of concentrated aqueous solutions. The behavior of these fluids has not been predicted from first principle theories. However, because of the importance of concentrated brines to many industrial and natural processes, there have been numerous efforts to develop accurate phenomenological expressions for predicting the chemical behavior of these brines. One of the most successful of these efforts is that of Pitzer and coworkers. Incorporating the semiempirical equations of Pitzer, we have shown at UCSD that we can create highly accurate models of brine-solid-gas chemistry.

  15. The effects of using screencasting as a multimedia pre-training tool to manage the intrinsic cognitive load of chemical equilibrium instruction for advanced high school chemistry students

    NASA Astrophysics Data System (ADS)

    Musallam, Ramsey

    Chemistry is a complex knowledge domain. Specifically, research notes that Chemical Equilibrium presents greater cognitive challenges than other topics in chemistry. Cognitive Load Theory describes the impact a subject, and the learning environment, have on working memory. Intrinsic load is the facet of Cognitive Load Theory that explains the complexity innate to complex subjects. The purpose of this study was to build on the limited research into intrinsic cognitive load, by examining the effects of using multimedia screencasts as a pre-training technique to manage the intrinsic cognitive load of chemical equilibrium instruction for advanced high school chemistry students. A convenience sample of 62 fourth-year high school students enrolled in an advanced chemistry course from a co-ed high school in urban San Francisco were given a chemical equilibrium concept pre-test. Upon conclusion of the pre-test, students were randomly assigned to two groups: pre-training and no pre-training. The pre-training group received a 10 minute and 52 second pre-training screencast that provided definitions, concepts and an overview of chemical equilibrium. After pre-training both group received the same 50-minute instructional lecture. After instruction, all students were given a chemical equilibrium concept post-test. Independent sample t-tests were conducted to examine differences in performance and intrinsic load. No significant differences in performance or intrinsic load, as measured by ratings of mental effort, were observed on the pre-test. Significant differences in performance, t(60)=3.70, p=.0005, and intrinsic load, t(60)=5.34, p=.0001, were observed on the post-test. A significant correlation between total performance scores and total mental effort ratings was also observed, r(60)=-0.44, p=.0003. Because no significant differences in prior knowledge were observed, it can be concluded that pre-training was successful at reducing intrinsic load. Moreover, a significant

  16. An overview of the fundamentals of the chemistry of silica with relevance to biosilicification and technological advances.

    PubMed

    Belton, David J; Deschaume, Olivier; Perry, Carole C

    2012-05-01

    Biomineral formation is widespread in nature, and occurs in bacteria, single-celled protists, plants, invertebrates, and vertebrates. Minerals formed in the biological environment often show unusual physical properties (e.g. strength, degree of hydration) and often have structures that exhibit order on many length scales. Biosilica, found in single-celled organisms through to higher plants and primitive animals (sponges), is formed from an environment that is undersaturated with respect to silicon, and under conditions of approximately neutral pH and relatively low temperatures of 4-40 °C compared to those used industrially. Formation of the mineral may occur intracellularly or extracellularly, and specific biochemical locations for mineral deposition that include lipids, proteins and carbohydrates are known. In most cases, the formation of the mineral phase is linked to cellular processes, an understanding of which could lead to the design of new materials for biomedical, optical and other applications. In this contribution, we describe the aqueous chemistry of silica, from uncondensed monomers through to colloidal particles and 3D structures, that is relevant to the environment from which the biomineral forms. We then describe the chemistry of silica formation from alkoxides such as tetraethoxysilane, as this and other silanes have been used to study the chemistry of silica formation using silicatein, and such precursors are often used in the preparation of silicas for technological applications. The focus of this article is on the methods, experimental and computational, by which the process of silica formation can be studied, with an emphasis on speciation. PMID:22333209

  17. Chemistry in Microfluidic Channels

    ERIC Educational Resources Information Center

    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. Complementary Spectroscopic Assays for Investigating Protein-Ligand Binding Activity: A Project for the Advanced Chemistry Laboratory

    ERIC Educational Resources Information Center

    Mascotti, David P.; Waner, Mark J.

    2010-01-01

    A protein-ligand binding, guided-inquiry laboratory project with potential application across the advanced undergraduate curriculum is described. At the heart of the project are fluorescence and spectrophotometric assays utilizing biotin-4-fluorescein and streptavidin. The use of the same stock solutions for an assay that may be examined by two…

  19. Computational chemistry

    NASA Technical Reports Server (NTRS)

    Arnold, J. O.

    1987-01-01

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

  20. Advanced modeling of nitrogen oxide emissions in circulating fluidized bed combustors: Parametric study of coal combustion and nitrogen compound chemistries

    SciTech Connect

    Kilpinen, P.; Kallio, S.; Hupa, M.

    1999-07-01

    This paper describes work-in-progress aimed at developing an emission model for circulating fluidized bed combustors using detailed homogeneous and heterogeneous chemical kinetics. The main emphasis is on nitrogen oxides (NO{sub x}, N{sub 2}O) but also unburned gases (CO, C{sub x}H{sub y}) and sulfur dioxide (SO{sub 2}) will be investigated in the long run. The hydrodynamics is described by a 1.5-dimensional model where the riser is divided into three regions: a dense bubbling bed at the bottom, a vigorously mixed splash zone, and a transport zone. The two latter zones are horizontally split into a core region and an annular region. The solids circulation rate is calculated from the known solids inventory and the pressure and mass balances over the entire circulation loop. The solids are divided into classes according to size and type or particle. The model assumes instantaneous fuel devolatilization at the bottom and an even distribution of volatiles in the suspension phase of the dense bed. For addition of secondary air, a complete penetration and an instantaneous mixing with the combustor gases in the core region is assumed. The temperature distribution is assumed to be known, and no energy balance is solved. A comprehensive kinetic scheme of about 300 elementary gas-phase reactions is used to describe the homogeneous oxidation of the volatiles including both hydrocarbon and volatile-nitrogen components (NH{sub 3}, HCN). Heterogeneous char combustion to CO and CO{sub 2}, and char-nitrogen conversion to NO, N{sub 2}O, and N{sub 2} are described by a single particle model that includes 15 reaction steps given in the form of 6 net reaction paths. In the paper, the model is briefly described. A special emphasis is put on the evaluation of chemistry submodels. Modeling results on nitrogen oxides' formation are compared with measured concentration profiles in a 12 MW CFBC riser from literature. The importance of accurate chemistry description on predictions is

  1. Chemistry of soil solutions

    SciTech Connect

    Elprince, A.M.

    1986-01-01

    Designed for advanced undergraduate and graduate students and researchers, this book serves as an introduction to the field of soil chemistry and associated fields such as aquatic chemistry, geochemistry, environmental chemistry, oceanography, and public health. The volume includes discussions on the structure of adsorbed water, adsorption of inorganics, solubility, redox, solute transport, chemical modeling, and sampling and monitoring the soil solution. Important papers on these topics together with editor's comments place each of the carefully chosen papers in the proper context. Because the chemistry of soil solutions requires the knowledge of many aspects of science, introductory information is provided for each topic to cover its history of development, present knowledge, and future prospects.

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

    SciTech Connect

    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.

  3. A phenomenological analysis of the essence of the science education experience as perceived by female high school physics and advanced chemistry students

    NASA Astrophysics Data System (ADS)

    Papadimitriou, Michael

    The purpose of this phenomenological study was to describe the essential elements of the current science education experience as constructed by twelve female high school physics and advanced chemistry students. The expressed desired outcome was a description of the phenomenon from a participant point of view. Student recollections and interpretations of experiences were assessed for a twelve-week period. Data sources were student journals, autobiographies, interviews, focus group interviews and researcher observations. In addition, each participant completed the Test of Science Related Attitudes (Fraser, 1981) in order to create attitude profiles for triangulation with other data. While a wide range of aspects of the science education experience emerged, results showed that female students describe and interpret their science education experiences on the basis of actual interest in science, early science experiences, perception of ability, self-confidence, teacher attributes, parental and peer interaction, societal expectations, the nature of science, and gender. Of these factors, specifically, interest and curiosity, societal influence, the nature of science, lack of in-school experiences, the desire to help others, and general parent support were most impacting upon experience and the desire to continue science study. Moreover, the interaction of these factors is relevant. Very simply, early experiences are crucial to interest development. In general, parents can enhance this interest by providing science-related experiences. In the absence of early in-school experiences (i.e., which the participants reported), these out-of-school experiences become crucial. More importantly, quality instruction and parent and peer support are needed to foster science interest and to overcome the powerfully negative influence of society, the discriminatory nature of science, and the lack of experiences.

  4. Recent advances in isoxazole chemistry

    NASA Astrophysics Data System (ADS)

    Galenko, A. V.; Khlebnikov, A. F.; Novikov, M. S.; Pakalnis, V. V.; Rostovskii, N. V.

    2015-04-01

    The preparation methods and reactions of isoxazoles are described and systematized on the basis of analysis of the literature published from 2005 to present. In the discussion of synthesis, major attention is focused on the most efficient approaches: condensation of hydroxylamine with 1,3-dielectrophiles and reactions of nitrile oxides with alkenes and alkynes. Five-membered ring opening reactions leading to acyclic functionalized or other heterocyclic compounds are considered. The transformations of isoxazole derivatives that occur without ring cleavage to form fused heterocyclic systems, as well as reactions that lead to the introduction of C-substituents into isoxazoles, are considered. Data on the biological activity of some isoxazole derivatives are reported. The bibliography includes 439 references.

  5. PNNL's 'PEGASUS' Advances Atmospheric Chemistry

    SciTech Connect

    Berkowitz, Carl M.; Eades, Robert A.

    2001-04-16

    Presented an overview of software design to maximize computational efficiency on a massively parallel computing system. Also gave highlights of scientific results from this code, focusing primarily on how we can distinguish between stratospheric ozone in remote atmospheres and ozone generated from NOx/VOC chemical mechanisms.

  6. Spreadsheets in Advanced Physical Chemistry.

    ERIC Educational Resources Information Center

    Kari, Roy

    1990-01-01

    Described are several spreadsheet templates which use the functions of iteration and logical look-up which allow students to calculate and graph quantum mechanical functions and to simulate rotational and vibrational energy level and spectra. The templates are listed in the appendix. (KR)

  7. A Quantum Chemistry Concept Inventory for Physical Chemistry Classes

    ERIC Educational Resources Information Center

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

    2016-01-01

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

  8. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Thirteen ideas are presented that may be of use to chemistry teachers. Topics covered include vitamin C, industrial chemistry, electrical conductivity, electrolysis, alkali metals, vibration modes infra-red, dynamic equilibrium, and some new demonstrations in gaseous combinations. (PS)

  9. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

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

  10. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents background information, laboratory procedures, classroom materials/activities, and chemistry experiments. Topics include sublimation, electronegativity, electrolysis, experimental aspects of strontianite, halide test, evaluation of present and future computer programs in chemistry, formula building, care of glass/saturated calomel…

  11. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents background information, laboratory procedures, classroom materials/activities, and experiments for chemistry. Topics include superheavy elements, polarizing power and chemistry of alkali metals, particulate carbon from combustion, tips for the chemistry laboratory, interesting/colorful experiments, behavior of bismuth (III) iodine, and…

  12. The Chemistry of Health.

    ERIC Educational Resources Information Center

    National Inst. of General Medical Sciences (NIH), Bethesda, MD.

    This booklet, geared toward an advanced high school or early college-level audience, describes how basic chemistry and biochemistry research can spur a better understanding of human health. It reveals how networks of chemical reactions keep our bodies running smoothly. Some of the tools and technologies used to explore these reactions are…

  13. CLUSTER CHEMISTRY

    SciTech Connect

    Muetterties, Earl L.

    1980-05-01

    Metal cluster chemistry is one of the most rapidly developing areas of inorganic and organometallic chemistry. Prior to 1960 only a few metal clusters were well characterized. However, shortly after the early development of boron cluster chemistry, the field of metal cluster chemistry began to grow at a very rapid rate and a structural and a qualitative theoretical understanding of clusters came quickly. Analyzed here is the chemistry and the general significance of clusters with particular emphasis on the cluster research within my group. The importance of coordinately unsaturated, very reactive metal clusters is the major subject of discussion.

  14. Forensic Chemistry

    NASA Astrophysics Data System (ADS)

    Bell, Suzanne

    2009-07-01

    Forensic chemistry is unique among chemical sciences in that its research, practice, and presentation must meet the needs of both the scientific and the legal communities. As such, forensic chemistry research is applied and derivative by nature and design, and it emphasizes metrology (the science of measurement) and validation. Forensic chemistry has moved away from its analytical roots and is incorporating a broader spectrum of chemical sciences. Existing forensic practices are being revisited as the purview of forensic chemistry extends outward from drug analysis and toxicology into such diverse areas as combustion chemistry, materials science, and pattern evidence.

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

    SciTech Connect

    Ryan, R.R.

    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.

  16. Mineral Process Chemistry: A Special Study.

    ERIC Educational Resources Information Center

    Dudeney, A. W. L.

    1982-01-01

    Mineral Process Chemistry is one of the special study options of the Nuffield Advanced Science course in chemistry. Following general comments on mineral process chemistry, the subject matter of the option is described, focusing on copper and china clay. (Author/JN)

  17. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Twelve new chemistry expermiments are described. Broad areas covered include atomic structure, solubility, gaseous diffusion, endothermic reactions, alcohols, equilibrium, atomic volumes, and some improvised apparatus. (PS)

  18. Technetium chemistry

    SciTech Connect

    Burns, C.; Bryan, J.; Cotton, F.; Ott, K.; Kubas, G.; Haefner, S.; Barrera, J.; Hall, K.; Burrell, A.

    1996-04-01

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

  19. Decadal simulation and comprehensive evaluation of CESM/CAM5.1 with advanced chemistry, aerosol microphysics, and aerosol-cloud interactions

    NASA Astrophysics Data System (ADS)

    He, Jian; Zhang, Yang; Glotfelty, Tim; He, Ruoying; Bennartz, Ralf; Rausch, John; Sartelet, Karine

    2015-03-01

    Earth system models have been used for climate predictions in recent years due to their capabilities to include biogeochemical cycles, human impacts, as well as coupled and interactive representations of Earth system components (e.g., atmosphere, ocean, land, and sea ice). In this work, the Community Earth System Model (CESM) with advanced chemistry and aerosol treatments, referred to as CESM-NCSU, is applied for decadal (2001-2010) global climate predictions. A comprehensive evaluation is performed focusing on the atmospheric component—the Community Atmosphere Model version 5.1 (CAM5.1) by comparing simulation results with observations/reanalysis data and CESM ensemble simulations from the Coupled Model Intercomparison Project phase 5 (CMIP5). The improved model can predict most meteorological and radiative variables relatively well with normalized mean biases (NMBs) of -14.1 to -9.7% and 0.7-10.8%, respectively, although temperature at 2 m (T2) is slightly underpredicted. Cloud variables such as cloud fraction (CF) and precipitating water vapor (PWV) are well predicted, with NMBs of -10.5 to 0.4%, whereas cloud condensation nuclei (CCN), cloud liquid water path (LWP), and cloud optical thickness (COT) are moderately-to-largely underpredicted, with NMBs of -82.2 to -31.2%, and cloud droplet number concentration (CDNC) is overpredictd by 26.7%. These biases indicate the limitations and uncertainties associated with cloud microphysics (e.g., resolved clouds and subgrid-scale cumulus clouds). Chemical concentrations over the continental U.S. (CONUS) (e.g., SO42-, Cl-, OC, and PM2.5) are reasonably well predicted with NMBs of -12.8 to -1.18%. Concentrations of SO2, SO42-, and PM10 are also reasonably well predicted over Europe with NMBs of -20.8 to -5.2%, so are predictions of SO2 concentrations over the East Asia with an NMB of -18.2%, and the tropospheric ozone residual (TOR) over the globe with an NMB of -3.5%. Most meteorological and radiative variables

  20. Throwing the Book at Elementary Chemistry.

    ERIC Educational Resources Information Center

    Pauling, Linus

    1983-01-01

    Several examples of misinformation and advanced topics included in current chemistry textbooks are provided. Suggests that since these books tend to be too long, too advanced, and too heavy, revisions should be shorter and less costly, with confusing aspects of chemistry (such as molecular-orbital theory) left out completely. (JN)

  1. Synthesis of a Self-Healing Polymer Based on Reversible Diels-Alder Reaction: An Advanced Undergraduate Laboratory at the Interface of Organic Chemistry and Materials Science

    ERIC Educational Resources Information Center

    Weizman, Haim; Nielsen, Christian; Weizman, Or S.; Nemat-Nasser, Sia

    2011-01-01

    This laboratory experiment exposes students to the chemistry of self-healing polymers based on a Diels-Alder reaction. Students accomplish a multistep synthesis of a monomer building block and then polymerize it to form a cross-linked polymer. The healing capability of the polymer is verified by differential scanning calorimetry (DSC) experiments.…

  2. Nobel Chemistry in the Laboratory: Synthesis of a Ruthenium Catalyst for Ring-Closing Olefin Metathesis--An Experiment for the Advanced Inorganic or Organic Laboratory

    ERIC Educational Resources Information Center

    Greco, George E.

    2007-01-01

    An experiment for the upper-level undergraduate laboratory is described in which students synthesize a ruthenium olefin metathesis catalyst, then use the catalyst to carry out the ring-closing metathesis of diethyl diallylmalonate. The olefin metathesis reaction was the subject of the 2005 Nobel Prize in chemistry. The catalyst chosen for this…

  3. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Outlines laboratory procedures, demonstrations, teaching suggestions, and content information related to chemistry. Topics include polarizing power; calorimetry and momentum; microcomputers in school chemistry; a constant-volume dispenser for liquids, floating magnets, and crystal lattices; preparation of chromium; and solvent polarity and…

  4. Spotlight on medicinal chemistry education.

    PubMed

    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. PMID:24962279

  5. Development and implementation of an empirical frequency map for use in MD simulations of isotope-edited proteins, and, Development, implementation, and evaluation of an online student portal as a textbook replacement in an advanced general chemistry course

    NASA Astrophysics Data System (ADS)

    Shorb, Justin Matthew

    The first portion of this thesis describes an extension of work done in the Skinner group to develop an empirical frequency map for N-methylacetamide (NMA) in water. NMA is a peptide bond capped on either side by a methyl group and is therefore a common prototypical molecule used when studying complicated polypeptides and proteins. This amide bond is present along the backbone of every protein as it connects individual component amino acids. This amide bond also has a strong observable frequency in the IR due to the Amide-I mode (predominantly carbon-oxygen stretching motion). This project describes the simplification of the prior model for mapping the frequency of the Amide-I mode from the electric field due to the environment and develops a parallel implementation of this algorithm for use in larger biological systems, such as the trans-membrane portion of the tetrameric polypeptide bundle protein CD3zeta. The second portion of this thesis describes the development, implementation and evaluation of an online textbook within the context of a cohesive theoretical framework. The project begins by describing what is meant when discussing a digital textbook, including a survey of various types of digital media being used to deliver textbook-like content. This leads into the development of a theoretical framework based on constructivist pedagogical theory, hypertext learning theory, and chemistry visualization and representation frameworks. The implementation and design of ChemPaths, the general chemistry online text developed within the Chemistry Education Digital Library (ChemEd DL) is then described. The effectiveness of ChemPaths being used as a textbook replacement in an advanced general chemistry course is evaluated within the developed theoretical framework both qualitatively and quantitatively.

  6. Circumstellar chemistry

    NASA Technical Reports Server (NTRS)

    Glassgold, Alfred E.; Huggins, Patrick J.

    1987-01-01

    The study of the outer envelopes of cool evolved stars has become an active area of research. The physical properties of CS envelopes are presented. Observations of many wavelengths bands are relevant. A summary of observations and a discussion of theoretical considerations concerning the chemistry are summarized. Recent theoretical considerations show that the thermal equilibrium model is of limited use for understanding the chemistry of the outer CS envelopes. The theoretical modeling of the chemistry of CS envelopes provides a quantitive test of chemical concepts which have a broader interest than the envelopes themselves.

  7. Prominent Chemists Team Up to Review Frontiers in Chemistry.

    ERIC Educational Resources Information Center

    Baum, Rudy M.

    1989-01-01

    Discusses a symposium which focused on the influence of inorganic chemistry on organic synthesis, the impact of organic chemistry on biochemistry and vice versa, chemical reaction dynamics, and advances in inorganic chemistry. Explains the purpose of the symposium was to illustrate the intellectual dynamism of modern chemistry. (MVL)

  8. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Describes equipment, activities, and experiments useful in chemistry instruction, including among others, a rapid method to determine available chlorine in bleach, simple flame testing apparatus, and a simple apparatus demonstrating the technique of flash photolysis. (SK)

  9. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1973

    1973-01-01

    Several ideas are proposed for chemistry teachers to try in their classrooms. Subjects included are polymerization of acrylate, polymerization of styrene, conductivity, pollution, preparation of chlorine, redox equations, chemiluminescence, and molecular sieves. (PS)

  10. Nuclear Chemistry.

    ERIC Educational Resources Information Center

    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)

  11. Catalytic Chemistry.

    ERIC Educational Resources Information Center

    Borer, Londa; And Others

    1996-01-01

    Describes an approach for making chemistry relevant to everyday life. Involves the study of kinetics using the decomposition of hydrogen peroxide by vegetable juices. Allows students to design and carry out experiments and then draw conclusions from their results. (JRH)

  12. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1981

    1981-01-01

    Describes 13 activities, experiments and demonstrations, including the preparation of iron (III) chloride, simple alpha-helix model, investigating camping gas, redox reactions of some organic compounds, a liquid crystal thermometer, and the oxidation number concept in organic chemistry. (JN)

  13. Precolumbian Chemistry.

    ERIC Educational Resources Information Center

    Robinson, Janet Bond

    1995-01-01

    Describes the content and development of a curriculum that provides an approach to descriptive chemistry and the history of technology through consideration of the pottery, metallurgy, pigments, dyes, agriculture, and medicine of pre-Columbian people. (DDR)

  14. Radiation Chemistry

    NASA Astrophysics Data System (ADS)

    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.

  15. Digital biology and chemistry.

    PubMed

    Witters, Daan; Sun, Bing; Begolo, Stefano; Rodriguez-Manzano, Jesus; Robles, Whitney; Ismagilov, Rustem F

    2014-09-01

    This account examines developments in "digital" biology and chemistry within the context of microfluidics, from a personal perspective. Using microfluidics as a frame of reference, we identify two areas of research within digital biology and chemistry that are of special interest: (i) the study of systems that switch between discrete states in response to changes in chemical concentration of signals, and (ii) the study of single biological entities such as molecules or cells. In particular, microfluidics accelerates analysis of switching systems (i.e., those that exhibit a sharp change in output over a narrow range of input) by enabling monitoring of multiple reactions in parallel over a range of concentrations of signals. Conversely, such switching systems can be used to create new kinds of microfluidic detection systems that provide "analog-to-digital" signal conversion and logic. Microfluidic compartmentalization technologies for studying and isolating single entities can be used to reconstruct and understand cellular processes, study interactions between single biological entities, and examine the intrinsic heterogeneity of populations of molecules, cells, or organisms. Furthermore, compartmentalization of single cells or molecules in "digital" microfluidic experiments can induce switching in a range of reaction systems to enable sensitive detection of cells or biomolecules, such as with digital ELISA or digital PCR. This "digitizing" offers advantages in terms of robustness, assay design, and simplicity because quantitative information can be obtained with qualitative measurements. While digital formats have been shown to improve the robustness of existing chemistries, we anticipate that in the future they will enable new chemistries to be used for quantitative measurements, and that digital biology and chemistry will continue to provide further opportunities for measuring biomolecules, understanding natural systems more deeply, and advancing molecular and

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

    SciTech Connect

    Not Available

    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)

  17. Chemistry Experiments

    NASA Technical Reports Server (NTRS)

    Brasseur, Guy; Remsberg, Ellis; Purcell, Patrick; Bhatt, Praful; Sage, Karen H.; Brown, Donald E.; Scott, Courtney J.; Ko, Malcolm K. W.; Tie, Xue-Xi; Huang, Theresa

    1999-01-01

    The purpose of the chemistry component of the model comparison is to assess to what extent differences in the formulation of chemical processes explain the variance between model results. Observed concentrations of chemical compounds are used to estimate to what degree the various models represent realistic situations. For readability, the materials for the chemistry experiment are reported in three separate sections. This section discussed the data used to evaluate the models in their simulation of the source gases and the Nitrogen compounds (NO(y)) and Chlorine compounds (Cl(y)) species.

  18. Tropospheric chemistry

    NASA Technical Reports Server (NTRS)

    Mohnen, V. A.; Chameides, W.; Demerjian, K. L.; Lenschow, D. H.; Logan, J. A.; Mcneal, R. J.; Penkett, S. A.; Platt, U.; Schurath, U.; Dias, P. D.

    1985-01-01

    The chemistry of the background troposphere, the source region, and the transition regions are discussed. The troposphere is governed by heterogeneous chemistry far more so than the stratosphere. Heterogeneous processes of interest involve scavenging of trace gases by aerosols, cloud and precipitation elements leading to aqueous phase chemical reactions and to temporary and permanent removal of material from the gas phase. Dry deposition is a major removal process for ozone, as well as for other gases of importance in tropospheric photochemistry. These processes are also discussed.

  19. Polymer Chemistry

    NASA Technical Reports Server (NTRS)

    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.

  20. Impact of reaction products from building materials and furnishings on indoor air quality—A review of recent advances in indoor chemistry

    NASA Astrophysics Data System (ADS)

    Uhde, E.; Salthammer, T.

    The variety of chemical substances present in modern building products, household products and furnishings provides potential for chemical reactions in the material (case 1), on the material surface (case 2) and in the gas phase (case 3). Such "indoor chemistry" is known as one of the main reasons for primary and secondary emissions. The conditions of production often cause unwanted side reactions and a number of new compounds can be found in finished products. Elevated temperatures are responsible for the degradation of cellulose, decomposition of non-heat-resistant additives and other thermally induced reactions like Diels-Alder synthesis. Heterogeneous chemistry takes place on the surface of materials. Well-known examples are the formation of aliphatic aldehydes from the oxidation of unsaturated fatty acids or the cleavage of photoinitiators under the influence of light. In case of composite flooring structures hydrolysis is one of the major pathways for the appearance of alcohols from esters. If different kinds of material are fixed together, emissions of new VOCs formed by inter-species reactions are possible. Other indoor air pollutants are formed by rearrangement of cleavage products or by metabolism. Compounds with -C dbnd C- bonds like terpenes, styrene, 4-phenylcyclohexene, etc. undergo gas phase reactions with O 3, NO x, OH and other reactive gases. It has been shown that such products derived from indoor-related reactions may have a negative impact on indoor air quality due to their low odor threshold or health-related properties. Therefore, the understanding of primary and secondary emissions and the chemical processes behind is essential for the evaluation of indoor air quality. This publication gives an overview on the current state of research and new findings regarding primary and secondary emissions from building products and furnishings.

  1. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

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

  2. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1983

    1983-01-01

    Presents chemistry experiments, laboratory procedures, demonstrations, teaching suggestions, and classroom materials/activities. These include: game for teaching ionic formulas; method for balancing equations; description of useful redox series; computer programs (with listings) for water electrolysis simulation and for determining chemical…

  3. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1978

    1978-01-01

    Describes some laboratory apparatus, chemistry experiments and demonstrations, such as a Kofler block melting point apparatus, chromatographic investigation of the phosphoric acid, x-ray diffraction, the fountain experiment, endothermic sherbet, the measurement of viscosity, ionization energies and electronic configurations. (GA)

  4. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1982

    1982-01-01

    Presents procedures, experiments, demonstrations, teaching suggestions, and information on a variety of chemistry topics including, for example, inert gases, light-induced reactions, calculators, identification of substituted acetophenones, the elements, analysis of copper minerals, extraction of metallic strontium, equilibrium, halogens, and…

  5. Chemistry Notes.

    ERIC Educational Resources Information Center

    School Science Review, 1980

    1980-01-01

    Presents 12 chemistry notes for British secondary school teachers. Some of these notes are: (1) a simple device for testing pH-meters; (2) portable fume cupboard safety screen; and (3) Mass spectroscopy-analysis of a mass peak. (HM)

  6. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1976

    1976-01-01

    Describes several chemistry projects, including solubility, formula for magnesium oxide, dissociation of dinitrogen tetroxide, use of 1-chloro-2, 4-dinitrobenzene, migration of ions, heats of neutralizations, use of pocket calculators, sonic cleaning, oxidation states of manganese, and cell potentials. Includes an extract from Chemical Age on…

  7. Chemistry Notes.

    ERIC Educational Resources Information Center

    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;…

  8. Chemistry Notes

    ERIC Educational Resources Information Center

    School Science Review, 1972

    1972-01-01

    Short articles on the alkylation of aniline, the preparation and properties of perbromate, using scrap copper in chemistry instruction, a safe method of burning hydrogen, and the use of an ion-charge model as an alternative to the mole concept in secondary school instruction. (AL)

  9. Medicinal chemistry for 2020

    PubMed Central

    Satyanarayanajois, Seetharama D; Hill, Ronald A

    2011-01-01

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

  10. Medicinal chemistry for 2020.

    PubMed

    Satyanarayanajois, Seetharama D; Hill, Ronald A

    2011-10-01

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

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

    ERIC Educational Resources Information Center

    Prilliman, Stephen G.

    2014-01-01

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

  12. Study on effects of powder and flake chemistry and morphology on the properties of Al-Cu-Mg-X-X-X powder metallurgy advanced aluminum alloys

    NASA Technical Reports Server (NTRS)

    Meschter, P. J.; Lederich, R. J.; Oneal, J. E.; Pao, P. S.

    1985-01-01

    The effects of alloy chemistry and particulate morphology on consolidation behavior and consolidated product properties in rapid solidification processed, powder-metallurgical Al-3Li-1.5Cu-1Mg-0.5Co-0.2Zr and Al-4.4Cu-1.5Mg-Fe-Ni-0.2Zr extrusions and forgings were studied. Microstructures and mechanical properties of both alloys are largely unaffected by particulate production method (vacuum atomization, ultrasonic atomization, or twin-roller quenching) and by particulate solidification rates between 1000 and 100,000 K/s. Consolidation processing by canning, cold compaction, degassing, and hot extrusion is sufficient to yield mechanical properties in the non-Li-containing alloy extrusions which are similar to those of 7075-Al, but ductilities and fracture toughnesses are inferior owing to poor interparticle bonding caused by lack of a vacuum-hot-pressing step during consolidation. Mechanical properties of extrusions are superior to those of forgings owing to the stronger textures produced by the more severe hot working during extrusion. The effects on mechanical properties of dispersoid size and volume fraction, substructural refinement, solid solution strengthening by Mg, and precipitate size and distribution are elucidated for both alloy types.

  13. Study of improved resins for advanced supersonic technology composites. Part 1: Heteroaromatic polymers containing ether groups. Part 2: Curing chemistry of aromatic polymers and composite studies

    NASA Technical Reports Server (NTRS)

    Takekoshi, T.; Hillig, W. B.; Mellinger, G. A.

    1975-01-01

    Fourteen ether-containing, aromatic dianhydrides have been synthesized from N-phenyl-3 or 4-nitrophthalimide and various bisphenols. The process involves nucleophilic displacement of activated nitro groups with bisphenolate ions. Ether-containing dianhydrides were indefinitely stable in the presence of atmospheric moisture. One-step, high temperature solution polymerization of the ether-containing dianhydrides with m-phenylene diamine, 4,4'-oxydianiline and 1, 3-bis(4-aminophenoxy)benzene afforded 42 polyetherimides. The polyetherimides were all soluble in m-cresol except two which were found to be crystalline. The glass transition temperatures of the polyetherimides ranged from 178 to 277 C. Soluble polybenzimidazopyrrolones containing ether groups were also prepared from the same ether-containing dianhydrides and aromatic tetraamines by one-step solution polymerization. Using low molecular weight polyetherimides, various thermoset resin systems were developed and tested as matrices for fiber-reinforced composites. The curing chemistry involving reaction of the phthalonitrile group and the o-diaminophenyl group was found to be generally applicable to crosslinking various aromatic polymers other than polyimides.

  14. Nuclear Chemistry, Science (Experimental): 5316.62.

    ERIC Educational Resources Information Center

    Williams, Russell R.

    This nuclear chemistry module includes topics on atomic structure, instability of the nucleus, detection strengths and the uses of radioactive particles. Laboratory work stresses proper use of equipment and safe handling of radioactive materials. Students with a strong mathematics background may consider this course as advanced work in chemistry.…

  15. ISSUES IN LIGNIN CHEMISTRY. "THE HELSINKI CONNECTION"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This presentation covers advances in lignin chemistry (and our Helsinki connection) on dibenzodioxocins, spirodienones, and reduced structures in lignins. It also explores the various roles in defending lignification theory (based on Freudenberg's original hypothesis) against a supposed new contende...

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

    SciTech Connect

    Ryan, R.R.

    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.

  17. Covalent Chemistry beyond Molecules.

    PubMed

    Jiang, Juncong; Zhao, Yingbo; Yaghi, Omar M

    2016-03-16

    Linking molecular building units by covalent bonds to make crystalline extended structures has given rise to metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), thus bringing the precision and versatility of covalent chemistry beyond discrete molecules to extended structures. The key advance in this regard has been the development of strategies to overcome the "crystallization problem", which is usually encountered when attempting to link molecular building units into covalent solids. Currently, numerous MOFs and COFs are made as crystalline materials in which the large size of the constituent units provides for open frameworks. The molecular units thus reticulated become part of a new environment where they have (a) lower degrees of freedom because they are fixed into position within the framework; (b) well-defined spatial arrangements where their properties are influenced by the intricacies of the pores; and (c) ordered patterns onto which functional groups can be covalently attached to produce chemical complexity. The notion of covalent chemistry beyond molecules is further strengthened by the fact that covalent reactions can be carried out on such frameworks, with full retention of their crystallinity and porosity. MOFs are exemplars of how this chemistry has led to porosity with designed metrics and functionality, chemically-rich sequences of information within their frameworks, and well-defined mesoscopic constructs in which nanoMOFs enclose inorganic nanocrystals and give them new levels of spatial definition, stability, and functionality. PMID:26863450

  18. (Pesticide chemistry)

    SciTech Connect

    Barnthouse, L.W.

    1990-09-04

    This report summarizes a trip by L. W. Barnthouse of the Environmental Sciences Division (ESD), Oak Ridge National Laboratory (ORNL), to Hamburg, Federal Republic of Germany (FRG), where he participated in the 7th International Congress of Pesticide Chemistry. He chaired a workshop on experimental systems for determining effects of pesticides on nontarget organisms and gave an oral presentation at a symposium on pesticide risk assessment. Before returning to the United States, Dr. Barnthouse visited the Netherlands Institute for Sea Research in Texel, the Netherlands.

  19. Undergraduate Professional Education in Chemistry: Guidelines and Evaluation Procedures.

    ERIC Educational Resources Information Center

    American Chemical Society, Washington, DC.

    Provided are guidelines for evaluating undergraduate professional education in chemistry. The guidelines summarize an approved program as including: 400 hours of classroom work; 500 hours of laboratory work; a core curriculum covering principles of analytical, inorganic, organic, and physical chemistry; 1 year of advanced work in chemistry or…

  20. Comparing Recent Organizing Templates for Test Content between ACS Exams in General Chemistry and AP Chemistry

    ERIC Educational Resources Information Center

    Holme, Thomas

    2014-01-01

    Two different versions of "big ideas" rooted content maps have recently been published for general chemistry. As embodied in the content outline from the College Board, one of these maps is designed to guide curriculum development and testing for advanced placement (AP) chemistry. The Anchoring Concepts Content Map for general chemistry…

  1. Tropospheric Chemistry

    NASA Technical Reports Server (NTRS)

    Mohnen, V.

    1984-01-01

    The fundamental processes that control the chemical composition and cycles of the global troposphere and how these processes and properties affect the physical behavior of the atmosphere are examined. The long-term information needs for tropospheric chemistry are: to be able to predict tropospheric responses to perturbations, both natural and anthropogenic, of these cycles, and to provide the information required for the maintenance and effective future management of the atmospheric component of our global life support system. The processes controlling global tropospheric biogeochemical cycles include: the input of trace species into the troposphere, their long-range transport and distribution as affected by the mean wind and vertical venting, their chemical transformations, including gas to particle conversion, leading to the appearance of aerosols or aqueous phase reactions inside cloud droplets, and their removal from the troposphere via wet (precipitation) and dry deposition.

  2. Combustion chemistry

    SciTech Connect

    Brown, N.J.

    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).

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

    PubMed Central

    Garcia, Joel

    2012-01-01

    Recent advances in the coordination chemistry of Eu2+ are reviewed. Common synthetic routes for generating discrete Eu2+-containing complexes reported since 2000 are summarized, followed by a description of the reactivity of these complexes and their applications in reduction chemistry, polymerization, luminescence, and as contrast agents for magnetic resonance imaging. Rapid development of the coordination chemistry of Eu2+ has led to an upsurge in the utilization of Eu2+-containing complexes in synthetic chemistry, materials science, and medicine. PMID:23049283

  4. Mass spectrometry. [in organic chemistry

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  5. Why Teach Environmental Chemistry?

    ERIC Educational Resources Information Center

    Gardner, Marjorie H.

    1974-01-01

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

  6. Science Update: Inorganic Chemistry

    ERIC Educational Resources Information Center

    Rawls, Rebecca

    1978-01-01

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

  7. Science Update: Inorganic Chemistry.

    ERIC Educational Resources Information Center

    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)

  8. Trace Chemistry

    NASA Technical Reports Server (NTRS)

    Radhakrishnan, Krishnan; Whitefield, Philip

    1999-01-01

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

  9. Lessons for Introductory Chemistry

    NASA Astrophysics Data System (ADS)

    Martin, John S.; Blackburn, Edward V.

    2000-07-01

    These twelve lessons, and an introductory lesson, are tutorials in basic topics of introductory chemistry. They are suitable for school use, individual study, or distance learning. They are particularly valuable as review material for students in more advanced courses who may have been away from the subject for some time. They contain a great variety of problems and exercises driven by random-number generators, so that the same problem never repeats exactly. The lessons are, for the most part, Socratic dialogues in which the student is required to answer questions and perform simulated experiments in order to discover chemical principles. They are organized in an intuitive chapter and page structure. One may move readily around each lesson. There are many on-screen facilities such as help, data tables, and a calculator.

  10. Research on geothermal chemistry and advanced instrumentation

    NASA Astrophysics Data System (ADS)

    Robertus, R. J.; Shannon, D. W.; Sullivan, R. G.; Kindle, C. H.; Pool, K. H.

    1985-09-01

    Research at the Pacific Northwest Laboratory (PNL) focuses on long-term geothermal power plant reliability. Past work concentrated on development of continuous high-temperature probes for monitoring process variables. PNL also completed a comprehensive handbook of brine treatment processes as they relate to injection well longevity. A recently completed study analyzed corrosion in the hydrocarbon system of a binary cycle plant. Over the two-year monitoring period, corrosion rates were less than 1 MPY in any part of the hydrocarbon system. The system was kept completely dry so the rates seem reasonable. Present projects include: (1) determination of gas breakout conditions at the Herber Binary Demonstration Plant operated by San Diego Gas and Electric Company; (2) generation of water mixing solubility data; (3) installation of prototype leak detectors at the Herber Plant; and (4) evaluation of state-of-the-art particle counters.

  11. NEW ADVANCES IN BORON SOIL CHEMISTRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Boron is an essential micronutrient element required for plant growth. Boron deficiency is wide-spread in crop plants throughout the world especially in coarse-textured soils in humid areas. Boron toxicity can also occur, especially in arid regions under irrigation. Plants respond directly to the...

  12. Advances in chemistry applied to forensic science.

    PubMed

    Rendle, David F

    2005-12-01

    Acts of terrorism, an increase in the use of firearms, drug abuse, the use of so-called date-rape drugs, and driving whilst under the influence of drugs, are just some of the subjects frequently in the news. In the absence of fingermarks and of material leading to the recovery of DNA, the forensic scientist has to rely upon chemical analysis of trace amounts of materials including explosives, drugs, toxicological specimens, firearms discharge residues, fibres, glass, paint, soil etc., in order to establish or eliminate links between suspect and victim and/or scene. This tutorial review describes analytical problems facing the forensic chemist, and the current methods and techniques employed to tackle them. PMID:16284668

  13. Advanced polymer chemistry of organometallic anions

    SciTech Connect

    Chamberlin, R.M.; Abney, K.D.; Balaich, G.J.; Fino, S.A.

    1997-11-01

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of the project was to prepare and characterize new polymers incorporating cobalt dicarbollide. Specific goals were to prepare polymerizable cobalt dicarbollide monomers using the nucleophilic substitution route discovered in laboratories and to establish the reaction conditions required to form polymers from these complexes. This one-year project resulted in two publications (in press), and provided the foundation for further investigations into polymer synthesis and characterization using cobalt dicarbollide and other metallocarboranes. Interest in synthesizing organometallic polymers containing the cobalt bis(dicarbollide) anion is motivated by their possible application as cation exchange materials for the remediation of cesium-137 and strontium-90 from nuclear wastes.

  14. Advanced physical chemistry of carbon nanotubes.

    PubMed

    Li, Jun; Pandey, Gaind P

    2015-04-01

    The past decade has seen a surge of exciting research and applications of carbon nanotubes (CNTs) stimulated by deeper understanding of their fundamental properties and increasing production capability. The intrinsic properties of various CNTs were found to strongly depend on their internal microstructures. This review summarizes the fundamental structure-property relations of seamless tube-like single- and multiwalled CNTs and conically stacked carbon nanofibers, as well as the organized architectures of these CNTs (including randomly stacked thin films, parallel aligned thin films, and vertically aligned arrays). It highlights the recent development of CNTs as key components in selected applications, including nanoelectronics, filtration membranes, transparent conductive electrodes, fuel cells, electrical energy storage devices, and solar cells. Particular emphasis is placed on the link between the basic physical chemical properties of CNTs and the organized CNT architectures with their functions and performance in each application. PMID:25580625

  15. Advances in Non-Aqueous Chemistry

    ERIC Educational Resources Information Center

    Holliday, A. K.; Nicholls, D.

    1974-01-01

    A discussion concerning the choice of solvents for a chemical reaction is followed by an examination of the advantages of using liquid ammonia, oxide solvents, and molten salts as alternatives to water as a solvent. (DT)

  16. Advanced Physical Chemistry of Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Li, Jun; Pandey, Gaind P.

    2015-04-01

    The past decade has seen a surge of exciting research and applications of carbon nanotubes (CNTs) stimulated by deeper understanding of their fundamental properties and increasing production capability. The intrinsic properties of various CNTs were found to strongly depend on their internal microstructures. This review summarizes the fundamental structure-property relations of seamless tube-like single- and multiwalled CNTs and conically stacked carbon nanofibers, as well as the organized architectures of these CNTs (including randomly stacked thin films, parallel aligned thin films, and vertically aligned arrays). It highlights the recent development of CNTs as key components in selected applications, including nanoelectronics, filtration membranes, transparent conductive electrodes, fuel cells, electrical energy storage devices, and solar cells. Particular emphasis is placed on the link between the basic physical chemical properties of CNTs and the organized CNT architectures with their functions and performance in each application.

  17. NEW ADVANCES IN BORON SOIL CHEMISTRY

    EPA Science Inventory

    Boron is an essential plant micronutrient for which the range between deficiency and toxicity is narrower than for any other nutrient element. Plants respond directly to the amount of B in soil solution and only indirectly to the amount of B adsorbed on soil particle surfaces. ...

  18. NEW ADVANCES IN BORON SOIL CHEMISTRY - Paper

    EPA Science Inventory

    Boron is an essential plant micronutrient for which the range between deficiency and toxicity is narrower than for any other nutrient element. Plants respond directly to the amount of B in soil solution and only indirectly to the amount of B adsorbed on soil particle surfaces. ...

  19. Recent advances in the chemistry of spinosyns.

    PubMed

    Crouse, G D; Sparks, T C; Schoonover, J; Gifford, J; Dripps, J; Bruce, T; Larson, L L; Garlich, J; Hatton, C; Hill, R L; Worden, T V; Martynow, J G

    2001-02-01

    The spinosyns are a new class of fermentation-derived insect control agents that are effective against a variety of chewing insect pests. The successful introduction of spinosad into the agricultural marketplace represents an important milestone in the use of natural products for commercial pest control. The development of a natural product presents additional limitations relative to a synthetic material. While the latter affords some degree of control in building appropriate physical attributes such as photostability, a natural product, designed to function in a different environment, is often less suited for traditional spray applications. Despite its intrinsic photolability, spinosad is stable enough to perform under field conditions. In an effort to generate analogs with improved physical characteristics, we have developed a variety of conditions for selectively modifying different portions of the molecule, and we have discovered analogs with greater activity against a broader spectrum of pests. The inability to translate improved greenhouse activity to actual field conditions resulted in a detailed study of the effects of formulations and crystallinity on biological activity. Through this effort, measurably improved field performance of synthetic spinosyn analogs relative to the natural product have now been observed. PMID:11455648

  20. Advanced Undergraduate Experiments in Thermoanalytical Chemistry.

    ERIC Educational Resources Information Center

    Hill, J. O.; Magee, R. J.

    1988-01-01

    Describes several experiments using the techniques of thermal analysis and thermometric titrimetry. Defines thermal analysis and several recent branches of the technique. Notes most of the experiments use simple equipment and standard laboratory techniques. (MVL)

  1. Selected new developments in computational chemistry.

    PubMed Central

    Darden, T A; Bartolotti, L; Pedersen, L G

    1996-01-01

    Molecular dynamics is a general technique for simulating the time-dependent properties of molecules and their environments. Quantum mechanics, as applied to molecules or clusters of molecules, provides a prescription for predicting properties exactly (in principle). It is reasonable to expect that both will have a profound effect on our understanding of environmental chemistry in the future. In this review, we consider several recent advances and applications in computational chemistry. Images Figure 1. PMID:8722111

  2. Development of advanced macrosphelides: potent anticancer agents.

    PubMed

    Paek, Seung-Mann

    2015-01-01

    Synthetic approaches to macrosphelide derivatives, based on medicinal chemistry, are summarized. This review contains conventional medicinal chemistry approaches, combinatorial chemistry, fluorous tagging techniques and affinity chromatography preparation. In addition, advances in their apoptosis-inducing activities are also included. PMID:25764486

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

    ERIC Educational Resources Information Center

    Hofstein, Avi; Kesner, Miri

    2006-01-01

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

  4. Computational chemistry research

    NASA Technical Reports Server (NTRS)

    Levin, Eugene

    1987-01-01

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

  5. Research Advances: Nitric Oxide Synthase Reduces Cr(VI); The Chemistry of Popcorn: It's All About "Pop-Ability"; Nanotubes May Help Heal Broken Bones; New Method Unites Organic Materials and Nanotechnology

    NASA Astrophysics Data System (ADS)

    King, Angela G.

    2005-12-01

    An enzyme can reduce chromium ions and increase toxicity. Chemistry may reduce the number of unpopped kernels. Nanotubes provide scaffolding for bone growth. A new method will aid fabrication of drug-delivery agents.

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

    ERIC Educational Resources Information Center

    Burns, Mary Sue

    2001-01-01

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

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

    SciTech Connect

    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.

  8. Chemistry Of Atmospheric Brown Carbon

    SciTech Connect

    Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2015-05-27

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

  9. Environmental chemistry: Volume A

    SciTech Connect

    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.

  10. Special Report: Brain Chemistry.

    ERIC Educational Resources Information Center

    Krassner, Michael B.

    1983-01-01

    Chemical actions in the brain result in cognitive, emotional, neuroendocrine, neuromuscular, and/or neurocirculatory effects. Developments in understanding brain chemistry are discussed, considering among others, neurotransmitter chemistry, neuropeptides, drugs and the brain, antidepressants, and actions of minor tranquilizers. (JN)

  11. Chemistry for Potters.

    ERIC Educational Resources Information Center

    Denio, Allen A.

    1980-01-01

    Relates pottery making to chemistry by providing chemical information about clay, its origin, composition, properties, and changes that occur during firing; also describes glaze compositions, examples of redox chemistry, salt glazing, crystalline glazes, and problems in toxicity. (CS)

  12. Organometallic Chemistry of Molybdenum.

    ERIC Educational Resources Information Center

    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)

  13. Chemistry and Art.

    ERIC Educational Resources Information Center

    Berry, Martyn

    1999-01-01

    Describes a Chemistry and Art project developed for secondary students and teachers sponsored by the National Gallery and The Royal Society of Chemistry in the United Kingdom. Discusses aspects of the techniques used in creating five paintings as well as the chemistry involved in their making, deterioration, conservation, and restoration.…

  14. Teaching School Chemistry.

    ERIC Educational Resources Information Center

    Waddington, D. J., Ed.

    This eight-chapter book is intended for use by chemistry teachers, curriculum developers, teacher educators, and other key personnel working in the field of chemical education. The chapters are: (1) "The Changing Face of Chemistry" (J. A. Campbell); (2) "Curriculum Innovation in School Chemistry" (R. B. Ingel and A. M. Ranaweera); (3) "Some…

  15. Green Chemistry and Education.

    ERIC Educational Resources Information Center

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

    2000-01-01

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

  16. Environmental Chemistry Activities.

    ERIC Educational Resources Information Center

    Jackland, Thomas; And Others

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

  17. Chemistry on Stamps.

    ERIC Educational Resources Information Center

    Schreck, James O.

    1986-01-01

    Suggests how postage stamps can be incorporated into chemistry teaching. Categories considered include emergence of chemistry as a science, metric system, atoms (and molecules and ions), stoichiometry, energy relationships in chemical systems, chemical bonding, nuclear chemistry, biochemistry, geochemistry, matter (gases, liquids, and solids),…

  18. Chemistry as General Education

    ERIC Educational Resources Information Center

    Tro, Nivaldo J.

    2004-01-01

    The efficacy of different science and chemistry courses for science-major and non-major students, and the question of chemistry's contribution to general education are evaluated. Chemistry and science curriculum are too profession- and consumer-oriented, and to overcome this problem, it is advised that all disciplines must incorporate the major…

  19. History of Chemistry.

    ERIC Educational Resources Information Center

    Servos, John W.

    1985-01-01

    Discusses the development of chemistry in the United States by considering: (1) chemistry as an evolving body of ideas/techniques, and as a set of conceptual resources affecting and affected by the development of other sciences; and (2) chemistry related to the history of American social and economic institutions and practices. (JN)

  20. Automated Water Chemistry Control at University of Virginia Pools.

    ERIC Educational Resources Information Center

    Krone, Dan

    1997-01-01

    Describes the technologically advanced aquatic and fitness center at the University of Virginia. Discusses the imprecise water chemistry control at the former facility and its intensive monitoring requirements. Details the new chemistry control standards initiated in the new center, which ensure constant chlorine and pH levels. (RJM)

  1. Melt Chemistry, Relaxation, and Solidification Kenetics of Glasses

    SciTech Connect

    Li, Hong; Ray, Chandra S.; Strachan, Denis M.; Weber, Richard; Yue, Yuanzheng

    2005-04-24

    In recent years, advanced spectroscopic analyses and theretical modeling are being used extensively as complementary tools to study the local structure in glasses and melts, particualarly, with respect to chemistry and bulk properties. Therefore, the current understanding of melt chemistry, from diverse yet complementary research results are highlighted in this volume.

  2. PhET Interactive Simulations: Transformative Tools for Teaching Chemistry

    ERIC Educational Resources Information Center

    Moore, Emily B.; Chamberlain, Julia M.; Parson, Robert; Perkins, Katherine K.

    2014-01-01

    Developing fluency across symbolic-, macroscopic-, and particulate-level representations is central to learning chemistry. Within the chemistry education community, animations and simulations that support multi-representational fluency are considered critical. With advances in the accessibility and sophistication of technology,…

  3. Static Chemistry in Disks or Clouds

    NASA Astrophysics Data System (ADS)

    Semenov, D.; Wiebe, D.

    2006-11-01

    This FORTRAN77 code can be used to model static, time-dependent chemistry in ISM and circumstellar disks. Current version is based on the OSU'06 gas-grain astrochemical network with all updates to the reaction rates, and includes surface chemistry from Hasegawa & Herbst (1993) and Hasegawa, Herbst, and Leung (1992). Surface chemistry can be modeled either with the standard rate equation approach or modified rate equation approach (useful in disks). Gas-grain interactions include sticking of neutral molecules to grains, dissociative recombination of ions on grains as well as thermal, UV, X-ray, and CRP-induced desorption of frozen species. An advanced X-ray chemistry and 3 grain sizes with power-law size distribution are also included. An deuterium extension to this chemical model is available.

  4. Chemistry Modeling for Aerothermodynamics and TPS

    NASA Technical Reports Server (NTRS)

    Wang, Dun-You; Stallcop, James R.; Dateo, Christopher E.; Schwenke, David W.; Haliciogiu, Timur; Huo, Winifred

    2004-01-01

    Recent advances in supercomputers and highly scalable quantum chemistry software render computational chemistry methods a viable means of providing chemistry data for aerothermal analysis at a specific level of confidence. Four examples of first principles quantum chemistry calculations will be presented. The study of the highly nonequilibrium rotational distribution of nitrogen molecule from the exchange reaction N + N2 illustrates how chemical reactions can influence the rotational distribution. The reaction C2H + H2 is one example of a radical reaction that occurs during hypersonic entry into a methane containing atmosphere. A study of the etching of Si surface illustrates our approach to surface reactions. A recently developed web accessible database and software tool (DDD) that provides the radiation profile of diatomic molecules is also described.

  5. Chemistry Modeling for Aerothermodynamics and TPS

    NASA Technical Reports Server (NTRS)

    Wang, Dunyou; Stallcop, James R.; Dateo, Christopher e.; Schwenke, David W.; Halicioglu, Timur; Huo, winifred M.

    2005-01-01

    Recent advances in supercomputers and highly scalable quantum chemistry software render computational chemistry methods a viable means of providing chemistry data for aerothermal analysis at a specific level of confidence. Four examples of first principles quantum chemistry calculations will be presented. Study of the highly nonequilibrium rotational distribution of a nitrogen molecule from the exchange reaction N + N2 illustrates how chemical reactions can influence rotational distribution. The reaction C2H + H2 is one example of a radical reaction that occurs during hypersonic entry into an atmosphere containing methane. A study of the etching of a Si surface illustrates our approach to surface reactions. A recently developed web accessible database and software tool (DDD) that provides the radiation profile of diatomic molecules is also described.

  6. School Chemistry vs. Chemistry in Research: An Exploratory Experiment.

    ERIC Educational Resources Information Center

    Habraken, Clarisse L.; Buijs, Wim; Borkent, Hens; Ligeon, Willy; Wender, Harry; Meijer, Marijn

    2001-01-01

    Reports on a study exploring why students are not studying chemistry. Three groups of graduating high school students and their chemistry teachers stayed at a research institute working on molecular modeling and wrote essays on school chemistry versus chemistry in research. Concludes that school chemistry does not convey today's chemistry in…

  7. American Association for Clinical Chemistry

    MedlinePlus

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

  8. Context-Based Chemistry: The Salters Approach

    ERIC Educational Resources Information Center

    Bennett, Judith; Lubben, Fred

    2006-01-01

    This paper describes briefly the development and key features of one of the major context-based courses for upper high school students, Salters Advanced Chemistry. It goes on to consider the research evidence on the impact of the course, focusing on teachers' views, and, in particular, on students' affective and cognitive responses. The research…

  9. The AP Descriptive Chemistry Question: Student Errors

    ERIC Educational Resources Information Center

    Crippen, Kent; Brooks, David W.

    2005-01-01

    For over a decade, the authors have been involved in a design theory experiment providing software for high school students preparing for the descriptive question on the Advanced Placement (AP) chemistry examination. Since 1997, the software has been available as a Web site offering repeatable practice. This study describes a 4-year project during…

  10. Cognitive Apprenticeship Theory and Graduate Chemistry Education

    NASA Astrophysics Data System (ADS)

    Stewart, K. K.; Lagowski, J. J.

    2003-12-01

    We address the issues of reform in laboratory instruction by linking the critical details in that process to graduate programs designed to teach advanced students the process(es) of "doing" chemistry. The link is the theory of cognitive development, which we show is an excellent model for the training of graduate students.

  11. Computational Chemistry and Lubrication

    NASA Technical Reports Server (NTRS)

    Zehe, Michael J.

    1998-01-01

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

  12. Venus Middle Atmosphere Chemistry

    NASA Astrophysics Data System (ADS)

    Mills, F. P.; Sundaram, M.; Slanger, T. G.; Allen, M.; Yung, Y. L.

    2005-08-01

    Venus is the most similar planet to Earth, and years of research have sought to understand their similarities and differences. Yet, it is still not clear what chemical processes maintain the long-term stability of Venus' primarily CO2 atmosphere. CO2 dissociates into CO and O after absorbing photons at wavelengths < 210 nm. These O atoms should combine to form O2, and observations of intense airglow confirm rapid production of O2 on both day and night sides. CO and O2 are sufficiently stable that an initially pure CO2 atmosphere would rapidly evolve to have 7-8% CO and 3.5-4% O2 [1]. The observed upper limit on O2 (0.3 ppm [2]), however, indicates catalytic mechanisms [3], rapidly convert CO and oxygen into CO2. The current understanding of Venus middle atmosphere chemistry, the state of lab data, and prospects for advances based on Venus Express will be reviewed. Recent work evaluating newly proposed mechanisms for producing CO2, which could be important depending on the rates of poorly constrained reactions, will be described. This research was supported by funding from NASA's Planetary Atmospheres program and the Australian Research Council. Part of this work was carried out by the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. [1] Nair, et al., Icarus 111, 124 (1994), [2] Trauger and Lunine, Icarus 55, 272 (1983), [3] Pernice, et al., PNAS 101, 14007 (2004)

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

    SciTech Connect

    Heiken, J.H.; Lindberg, H.A.

    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.

  14. A Test of Strategies for Enhanced Learning of AP Descriptive Chemistry

    ERIC Educational Resources Information Center

    Kotcherlakota, Suhasini; Brooks, David W.

    2008-01-01

    The Advanced Placement (AP) Descriptive Chemistry Website allows users to practice chemistry problems. This study involved the redesign of the Website using worked examples to enhance learner performance. The population sample for the study includes users (students and teachers) interested in learning descriptive chemistry materials. The users…

  15. Industrial Chemistry and School Chemistry: Making chemistry studies more relevant

    NASA Astrophysics Data System (ADS)

    Hofstein, Avi; Kesner, Miri

    2006-07-01

    In this paper, we present the development and implementation over the period of more than 15 years of learning materials focusing on industrial chemistry as the main theme. The work was conducted in the Department of Science Teaching at the Weizmann Institute of Science, Israel. The project’s general goal was to teach chemistry concepts in the context of industrial chemistry in order to present chemistry as a relevant topic both to the students personally as well as to the society in which they live. The learning materials that were developed during this period were in alignment with the changes and reforms that were conducted in the Israeli educational system. These developments were accompanied with intensive and comprehensive professional development courses and workshops. In addition, several research and evaluation projects were conducted with the goal to assess students’ achievements and to probe into the students’ perceptions regarding the classroom learning environment and the teachers’ and students’ attitudes towards the various instructional and learning materials techniques that were implemented in the programme throughout these years. This paper is structured attempting to describe the curricular cycle in alignment with Goodlad’s and Van den Akker’s curriculum representations.

  16. Atmospheric Chemistry Over Southern Africa

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    campaigns such as Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE-A), Southern African Fire-Atmosphere Research Initiative (SAFARI-92), and Southern African Regional Science Initiative (SAFARI 2000). Since those large international efforts, satellites have matured enough to enable quantifiable measurements of regional land surface, atmosphere, and ocean. In addition, global and chemical transport models have also been advanced to incorporate various data. Thus, the timing of the workshop was right for a full-fledged re-assessment of the chemistry, physics, and socio-economical impacts caused by pollution in the region, including a characterization of sources, deposition, and feedbacks with climate change.

  17. Connecting Algebra and Chemistry.

    ERIC Educational Resources Information Center

    O'Connor, Sean

    2003-01-01

    Correlates high school chemistry curriculum with high school algebra curriculum and makes the case for an integrated approach to mathematics and science instruction. Focuses on process integration. (DDR)

  18. Click Chemistry in Complex Mixtures: Bioorthogonal Bioconjugation

    PubMed Central

    McKay, Craig S.; Finn, M.G.

    2014-01-01

    The selective chemical modification of biological molecules drives a good portion of modern drug development and fundamental biological research. While a few early examples of reactions that engage amine and thiol groups on proteins helped establish the value of such processes, the development of reactions that avoid most biological molecules so as to achieve selectivity in desired bond-forming events has revolutionized the field. We provide an update on recent developments in bioorthogonal chemistry that highlights key advances in reaction rates, biocompatibility, and applications. While not exhaustive, we hope this summary allows the reader to appreciate the rich continuing development of good chemistry that operates in the biological setting. PMID:25237856

  19. Cooking with Chemistry.

    ERIC Educational Resources Information Center

    Grosser, Arthur E.

    1984-01-01

    Suggests chemistry of cooking and analysis of culinary recipes as subject matter for introducing chemistry to an audience, especially to individuals with neutral or negative attitudes toward science. Includes sample recipes and experiments and a table listing scientific topics with related cooking examples. (JN)

  20. High School Chemistry.

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 1983

    1983-01-01

    Preparation for college or life, working conditions and continuing education for high school chemistry teachers, and form/function of high school chemistry textbooks were addressed in presentations at the Seventh Biennial Conference on Chemical Education (Stillwater, Oklahoma 1982). Workshops, lectures, and demonstrations were also presented to…

  1. Process Analytical Chemistry.

    ERIC Educational Resources Information Center

    Callis, James B.; And Others

    1987-01-01

    Discusses process analytical chemistry as a discipline designed to supply quantitative and qualitative information about a chemical process. Encourages academic institutions to examine this field for employment opportunities for students. Describes the five areas of process analytical chemistry, including off-line, at-line, on-line, in-line, and…

  2. Undergraduate Chemistry Laboratory

    ERIC Educational Resources Information Center

    Bretz, Stacey Lowery; Fay, Michael; Bruck, Laura B.; Towns, Marcy H.

    2013-01-01

    Forty chemistry faculty from American Chemical Society-approved departments were interviewed to determine their goals for undergraduate chemistry laboratory. Faculty were stratified by type of institution, departmental success with regard to National Science Foundation funding for laboratory reform, and level of laboratory course. Interview…

  3. Movies in Chemistry Education

    ERIC Educational Resources Information Center

    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…

  4. Infrared Lasers in Chemistry.

    ERIC Educational Resources Information Center

    John, Phillip

    1982-01-01

    Selected infrared laser chemistry topics are discussed including carbon dioxide lasers, infrared quanta and molecules, laser-induced chemistry, structural isomerization (laser purification, sensitized reactions, and dielectric breakdown), and fundamental principles of laser isotope separation, focusing on uranium isotope separation. (JN)

  5. Chemistry from Issues.

    ERIC Educational Resources Information Center

    Harding, Jan; Donaldson, Jim

    1986-01-01

    Describes the "Chemistry from Issues" project at Chelsea College. Provides the background information, rationale, and overall structure of a proposed course about the importance of chemistry to common culture. Outlines one module about the British steel industry that has been taught at King's College. (TW)

  6. Chemistry of Moth Repellents

    ERIC Educational Resources Information Center

    Pinto, Gabriel

    2005-01-01

    An effective way to teach chemistry is to examine the substances used in daily life from a pedagogical viewpoint, from the overlap of science, technology, and society (STS). A study aims to engage students in the topic of moth repellents and to encourage them to investigate the chemistry in this familiar product using a set of questions.

  7. Chemistry and Biology

    ERIC Educational Resources Information Center

    Wigston, David L.

    1970-01-01

    Discusses the relationship between chemisty and biology in the science curriculum. Points out the differences in perception of the disciplines, which the physical scientists favoring reductionism. Suggests that biology departments offer a special course for chemistry students, just as the chemistry departments have done for biology students.…

  8. Coupled Phenomena in Chemistry.

    ERIC Educational Resources Information Center

    Matsubara, Akira; Nomura, Kazuo

    1979-01-01

    Various phenomena in chemistry and biology can be understood through Gibbs energy utilization. Some common phenomena in chemistry are explained including neutralization, hydrolysis, oxidation and reaction, simultaneous dissociation equilibrium of two weak acids, and common ion effect on solubility. (Author/SA)

  9. Stratospheric chemistry and transport

    NASA Technical Reports Server (NTRS)

    Prather, Michael; Garcia, Maria M.

    1990-01-01

    A Chemical Tracer Model (CTM) that can use wind field data generated by the General Circulation Model (GCM) is developed to implement chemistry in the three dimensional GCM of the middle atmosphere. Initially, chemical tracers with simple first order losses such as N2O are used. Successive models are to incorporate more complex ozone chemistry.

  10. Career Options in Chemistry.

    ERIC Educational Resources Information Center

    Belloli, Robert C.

    1985-01-01

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

  11. Chemistry and Philosophy

    ERIC Educational Resources Information Center

    Theobald, D. W.

    1970-01-01

    In the second article of a series, the author discusses some of the interactions between chemistry and philosophy. Evaluates chemistry's role within the scientific enterprise. Traces the rise and fall of the logical atom and argues for a new way of looking at science as an educational instrument. (RR)

  12. Opportunities in Chemistry.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC.

    Because of the changes occurring in the chemical sciences, a new survey of chemistry and its intellectual and economic impact was clearly needed. This report presents a current assessment of the status of chemistry and of the future opportunities in the field. This analysis contains: (1) an introductory chapter (establishing the need for the…

  13. Art in Chemistry; Chemistry in Art.

    ERIC Educational Resources Information Center

    Greenberg, Barbara R.; Patterson, Dianne

    High school teachers are often challenged to motivate students who have little or no interest in a subject and are bored with traditional instruction. This unique book is designed to help educators make chemistry classes more interesting and links art curriculum to practical applications, integrating the two subjects through scores of hands-on…

  14. EVOLVING FROM GREEN CHEMISTRY TO SUSTAINABLE CHEMISTRY

    EPA Science Inventory

    The twelve principles of green chemistry provide a foundation and pathway which allows researchers to incorporate greenness into existing reactions or when developing new technologies. Research from our laboratory has adopted many of these principles and utlizes them as a major c...

  15. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    ERIC Educational Resources Information Center

    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,…

  16. Moderator Chemistry Program

    SciTech Connect

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

    1990-11-01

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

  17. Moderator Chemistry Program

    SciTech Connect

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

    1990-11-01

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

  18. Environmental chemistry. 5th edition

    SciTech Connect

    Manahan, S.E. . Dept. of Chemistry)

    1991-01-01

    This book is organized around several major sections: aquatic Chemistry, atmospheric chemistry, the geosphere and hazardous wastes, toxicological chemistry, and resources and energy. Specific topics discussed in the book include a general introduction to environment chemistry, basic principles of aquatic chemistry, water pollution and water treatment, the essential role of microorganisms in aquatic chemical phenomena, atmospheric chemistry, a discussion of major threats to the global atmosphere (particularly greenhouse gases and ozone-depleting chemicals), the geosphere and hazardous substances, soil chemistry, and the nature and sources of hazardous wastes. The environmental chemistry of hazardous wastes, their treatment, minimization, and recycling, and the effects of these hazardous substances in also presented.

  19. Frontiers in analytical chemistry

    SciTech Connect

    Amato, I.

    1988-12-15

    Doing more with less was the modus operandi of R. Buckminster Fuller, the late science genius, and inventor of such things as the geodesic dome. In late September, chemists described their own version of this maxim--learning more chemistry from less material and in less time--in a symposium titled Frontiers in Analytical Chemistry at the 196th National Meeting of the American Chemical Society in Los Angeles. Symposium organizer Allen J. Bard of the University of Texas at Austin assembled six speakers, himself among them, to survey pretty widely different areas of analytical chemistry.

  20. Seawater Chemistry Package

    2005-11-23

    SeaChem Seawater Chemistry package provides routines to calculate pH, carbonate chemistry, density, and other quantities for seawater, based on the latest community standards. The chemistry is adapted from fortran routines provided by the OCMIP3/NOCES project, details of which are available at http://www.ipsl.jussieu.fr/OCMIP/. The SeaChem package can generate Fortran subroutines as well as Python wrappers for those routines. Thus the same code can be used by Python or Fortran analysis packages and Fortran ocean models alike.

  1. Computational quantum chemistry website

    SciTech Connect

    1997-08-22

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

  2. Magnetism in Chemistry

    ERIC Educational Resources Information Center

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

    1975-01-01

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

  3. General Chemistry for Engineers.

    ERIC Educational Resources Information Center

    Kybett, B. D.

    1982-01-01

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

  4. Information-Mapped Chemistry.

    ERIC Educational Resources Information Center

    Olympia, P. L., Jr.

    1979-01-01

    This paper describes the use of information mapping in chemistry and in other related sciences. Information mapping is a way of presenting information without paragraphs and unnecessary transitional phrases. (BB)

  5. Supplemental instruction in chemistry

    NASA Astrophysics Data System (ADS)

    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.

  6. Let's Stress Chemistry.

    ERIC Educational Resources Information Center

    Webb, Michael J.; And Others

    1983-01-01

    Two descriptive chemistry experiments are presented which foster development of students' skills in making observations and deductions. In addition, the experiments are designed to stress the importance of chemical behavior and clear presentation of experimental findings. (JN)

  7. Microcomputers in Teaching Chemistry.

    ERIC Educational Resources Information Center

    Sommers, Ray

    1981-01-01

    Describes the development, content, and implementation of a two-credit graduate course for teachers at the University of Wisconsin at Stevens Point in the use of microcomputers for teaching high school chemistry. (JJD)

  8. Environmental Bioinorganic Chemistry

    ERIC Educational Resources Information Center

    Ochiai, Ei-Ichiro

    1974-01-01

    Discusses some important aspects of bioinorganic chemistry, including interactions of organisms with metallic and nonmetallic elements and compounds. Indicates that many environmental problems are created by human exploitation of nature and technologies if studied from a bioinorganic chemical viewpoint. (CC)

  9. Chemistry for Nonscientists

    ERIC Educational Resources Information Center

    Weil, Thomas A.; And Others

    1974-01-01

    Discusses the case of DDT which can be introduced to nonscience students in a chemistry course, including the development of DDT, problems associated with its adverse effects, and curtailment of its use in our environments. (CC)

  10. Chemistry with a Peel.

    ERIC Educational Resources Information Center

    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)

  11. Chemistry Laboratory Safety Check

    ERIC Educational Resources Information Center

    Patnoe, Richard L.

    1976-01-01

    An accident prevention/safety check list for chemistry laboratories is printed. Included are checks of equipment, facilities, storage and handling of chemicals, laboratory procedures, instruction procedures, and items to be excluded from chemical laboratories. (SL)

  12. Water Chemistry: Seeking Information

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1977-01-01

    A survey of the available literature in water chemistry is presented. Materials surveyed include: texts, reference books, bibliographic resources, journals, American Chemical Society publications, proceedings, unpublished articles, and reports. (BT)

  13. Enzymes in Analytical Chemistry.

    ERIC Educational Resources Information Center

    Fishman, Myer M.

    1980-01-01

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

  14. Chemistry and Detective Fiction.

    ERIC Educational Resources Information Center

    Labianca, Dominick A.; Reeves, William J.

    1981-01-01

    Describes an interdisciplinary program consisting of two courses. The first course deals with the chemistry of drugs and poisons; the second course focuses on fictional works in which these drugs and poisons are central to the plots. (SK)

  15. Descriptive Inorganic Chemistry (by Geoff Rayner-Canham)

    NASA Astrophysics Data System (ADS)

    Rabinovich, Daniel

    1998-06-01

    Geoff Rayner-Canham. W. H. Freeman: New York, 1996. 492 pp. ISBN: 0-7167-2819-2. $67.95. There are plenty of good inorganic chemistry books on the market, from venerable reference works (e.g., Cotton and Wilkinson's Advanced Inorganic Chemistry, Greenwood and Earnshaw's Chemistry of the Elements) to "comprehensive" two-semester textbooks (e.g., Huheey, Keiter, and Keiter's Inorganic Chemistry: Principles of Structure and Reactivity, Douglas, McDaniel, and Alexander's Concepts and Models of Inorganic Chemistry). Undergraduate students, especially those new to inorganic chemistry, frequently find these books overwhelming in depth and length (not to mention weight!). Alternatively, some shorter books with less ambitious goals present an oversimplified view of the field or sacrifice conceptual material on behalf of sections on environmental, industrial, or biological chemistry. Rayner-Canham's Descriptive Inorganic Chemistry, a one-semester book aimed specifically at the introductory (sophomore) level, provides an excellent balance of theory and descriptive material, with a fresh look at traditional and current areas of interest in inorganic chemistry.

  16. Impact of surface chemistry

    PubMed Central

    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

  17. EPA Environmental Chemistry Laboratory

    NASA Technical Reports Server (NTRS)

    1993-01-01

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

  18. Acid-base chemistry

    SciTech Connect

    Hand, C.W.; Blewit, H.L.

    1985-01-01

    The book is not a research compendium and there are no references to the literature. It is a teaching text covering the entire range of undergraduate subject matter dealing with acid-base chemistry (some of it remotely) as taught in inorganic, analytical, and organic chemistry courses. The excellent chapters VII through IX deal in detail with the quantitative aspects of aqueous acid-base equilibria (salt hydrolysis and buffer, titrations, polyprotic and amphoteric substances).

  19. Computational Chemistry in the Pharmaceutical Industry: From Childhood to Adolescence.

    PubMed

    Hillisch, Alexander; Heinrich, Nikolaus; Wild, Hanno

    2015-12-01

    Computational chemistry within the pharmaceutical industry has grown into a field that proactively contributes to many aspects of drug design, including target selection and lead identification and optimization. While methodological advancements have been key to this development, organizational developments have been crucial to our success as well. In particular, the interaction between computational and medicinal chemistry and the integration of computational chemistry into the entire drug discovery process have been invaluable. Over the past ten years we have shaped and developed a highly efficient computational chemistry group for small-molecule drug discovery at Bayer HealthCare that has significantly impacted the clinical development pipeline. In this article we describe the setup and tasks of the computational group and discuss external collaborations. We explain what we have found to be the most valuable and productive methods and discuss future directions for computational chemistry method development. We share this information with the hope of igniting interesting discussions around this topic. PMID:26358802

  20. The Development of Multiple-Choice Items Consistent with the AP Chemistry Curriculum Framework to More Accurately Assess Deeper Understanding

    ERIC Educational Resources Information Center

    Domyancich, John M.

    2014-01-01

    Multiple-choice questions are an important part of large-scale summative assessments, such as the advanced placement (AP) chemistry exam. However, past AP chemistry exam items often lacked the ability to test conceptual understanding and higher-order cognitive skills. The redesigned AP chemistry exam shows a distinctive shift in item types toward…

  1. Evaluating Roadmaps to Portray and Develop Chemistry Teachers' PCK about Curricular Structures Concerning Sub-Microscopic Models

    ERIC Educational Resources Information Center

    Bindernagel, Janina A.; Eilks, Ingo

    2009-01-01

    This paper describes a study on research-oriented chemistry teacher education, in which fifty-six advanced, secondary school chemistry student teachers working in teams of two interviewed twenty-eight experienced chemistry teachers. The interviews focussed on teachers' personal viewpoints of how to best teach the different levels of…

  2. [Advances in the investigation of structure and function of G protein-coupled receptors (by awarding the Nobel Prize for Chemistry in 2012 to Robert Lefkowitz and Bryan Kobilka)].

    PubMed

    Shpakov, A O

    2013-01-01

    The Nobel Prize for Chemistry in 2012 was awarded to Robert Lefkowitz and Bryan Kobilka "for studies in G-protein-coupled receptors" (GPCR). In this review the most important discoveries of these Nobel Prize winners dealing with investigation of the structure and functions of GPCR were discussed and analyzed. In the 1980s, they were the first in the world to clone GPCR--the 32-adrenergic receptor. After 20 years, the team led by B. Kobilka for the first time prepared this receptor in the crystalline form and established its three-dimensional structure. In these studies, unique approaches for purification and crystallization of other receptors were developed. In 1980s, R. Lefkowitz and his colleagues discovered beta-arrestins that regulate signal transduction occurring via GPCR. Later they revealed that beta-arrestins were the most important members of signal transduction and were responsible for the signal transduction from the hormone-activated receptor to intracellular signaling cascades independently of heterotrimeric G-proteins. These and other outstanding discoveries of R. Lefkowitz and B. Kobilka have become the basis for the novel area of molecular biology and pharmacology--the molecular endocrinology of GPCR. PMID:25434187

  3. Technetium Chemistry in HLW

    SciTech Connect

    Hess, Nancy J.; Felmy, Andrew R.; Rosso, Kevin M.; Xia Yuanxian

    2005-06-06

    Tc contamination is found within the DOE complex at those sites whose mission involved extraction of plutonium from irradiated uranium fuel or isotopic enrichment of uranium. At the Hanford Site, chemical separations and extraction processes generated large amounts of high level and transuranic wastes that are currently stored in underground tanks. The waste from these extraction processes is currently stored in underground High Level Waste (HLW) tanks. However, the chemistry of the HLW in any given tank is greatly complicated by repeated efforts to reduce volume and recover isotopes. These processes ultimately resulted in mixing of waste streams from different processes. As a result, the chemistry and the fate of Tc in HLW tanks are not well understood. This lack of understanding has been made evident in the failed efforts to leach Tc from sludge and to remove Tc from supernatants prior to immobilization. Although recent interest in Tc chemistry has shifted from pretreatment chemistry to waste residuals, both needs are served by a fundamental understanding of Tc chemistry.

  4. Chemistry beyond positivism.

    PubMed

    Brandt, Werner W

    2003-05-01

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

  5. Collaborative Physical Chemistry Projects Involving Computational Chemistry

    NASA Astrophysics Data System (ADS)

    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.

  6. Reaction chemistry of cerium

    SciTech Connect

    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.

  7. Uranium triamidoamine chemistry.

    PubMed

    Gardner, Benedict M; Liddle, Stephen T

    2015-07-01

    Triamidoamine (Tren) complexes of the p- and d-block elements have been well-studied, and they display a diverse array of chemistry of academic, industrial and biological significance. Such in-depth investigations are not as widespread for Tren complexes of uranium, despite the general drive to better understand the chemical behaviour of uranium by virtue of its fundamental position within the nuclear sector. However, the chemistry of Tren-uranium complexes is characterised by the ability to stabilise otherwise reactive, multiply bonded main group donor atom ligands, construct uranium-metal bonds, promote small molecule activation, and support single molecule magnetism, all of which exploit the steric, electronic, thermodynamic and kinetic features of the Tren ligand system. This Feature Article presents a current account of the chemistry of Tren-uranium complexes. PMID:26035690

  8. Atmospheric chemistry research

    SciTech Connect

    Saylor, R.D. )

    1990-01-01

    Global environmental changes are occurring all around us, and the energy industry is a major player in the changes that are taking place. Wise energy policy can only be generated from a position of informed enlightenment and understanding about the environmental consequences of energy production and utilization. The atmospheric chemistry research being conducted at the University of Kentucky's Center for Applied Energy Research is geared toward providing the knowledge necessary to allow industrial and legislative officials to make responsible energy decisions in the 1990's and beyond. Three programs are described: the Kentucky Acid Deposition Program Precipitation chemistry network; modeling of regional and urban photochemistry and acid deposition; and modeling of global tropospheric chemistry.

  9. Interstellar sulfur chemistry

    NASA Technical Reports Server (NTRS)

    Prasad, S. S.; Huntress, W. T., Jr.

    1980-01-01

    The results of a chemical model of SO, CS, and OCS chemistry in dense clouds are summarized. The results are obtained from a theoretical study of sulfur chemistry in dense interstellar clouds using a large-scale time-dependent model of gas-phase chemistry. Among the results are the following: (1) owing to activation energy, the reaction of CS with O atoms is efficient as a loss mechanism of CS during the early phases of cloud evolution or in hot and oxygen-rich sources such as the KL nebula; (2) if sulfur is not abnormally depleted in dense clouds, then the observed abundances of SO, SO2, H2S, CS, OCS, H2CS, and SiS indicate that sulfur is mostly atomic in dense clouds; and (3) OCS is stable against reactions with neutral atoms and radicals in dense clouds.

  10. Chemistry WebBook

    National Institute of Standards and Technology Data Gateway

    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.

  11. Chemistry of Transactinides

    NASA Astrophysics Data System (ADS)

    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.

  12. Chemistry in cometary comae.

    PubMed

    Irvine, W M; Dickens, J E; Lovell, A J; Schloerb, F P; Senay, M; Bergin, E A; Jewitt, D; Matthews, H E

    1998-01-01

    Significant gas-phase chemistry occurs in the comae of bright comets, as is demonstrated here for the case of Comet Hale-Bopp. The abundance ratio of the two isomers, hydrogen cyanide and hydrogen isocyanide, is shown to vary with heliocentric distance in a way that is consistent with production of HNC by ion-molecule chemistry initiated by the photoionization of water. Likewise, the first maps of emission from HCO+ show an abundance and an extended distribution that are consistent with the same chemical model. PMID:9809016

  13. Computational Interstellar Chemistry

    NASA Astrophysics Data System (ADS)

    Hirata, So; Fan, Peng-Dong; Head-Gordon, Martin; Kamiya, Muneaki; Keçeli, Murat; Lee, Timothy J.; Shiozaki, Toru; Szczepanski, Jan; Vala, Martin; Valeev, Edward F.; Yagi, Kiyoshi

    Computational applications of electronic and vibrational many-body theories are increasingly indispensable in interpreting and, in some instances, predicting the spectra of gas-phase molecular species of importance in interstellar chemistry as well as in atmospheric and combustion chemistry. This chapter briefly reviews our methodological developments of electronic and vibrational many-body theories that are particularly useful for these gas-phase molecular problems. Their applications to anharmonic vibrational frequencies of triatomic and tetratomic interstellar molecules and to electronic absorption spectra of the radical ions of polycyclic aromatic hydrocarbons, which are ubiquitous in the interstellar medium, are also discussed.

  14. Revitalizing chemistry laboratory instruction

    NASA Astrophysics Data System (ADS)

    McBride, Phil Blake

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

  15. Chemistry in Second Life

    PubMed Central

    Lang, Andrew SID; Bradley, Jean-Claude

    2009-01-01

    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. PMID:19852781

  16. Nanophotonics and supramolecular chemistry

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  17. Chemistry in cometary comae

    NASA Technical Reports Server (NTRS)

    Irvine, W. M.; Dickens, J. E.; Lovell, A. J.; Schloerb, F. P.; Senay, M.; Bergin, E. A.; Jewitt, D.; Matthews, H. E.

    1998-01-01

    Significant gas-phase chemistry occurs in the comae of bright comets, as is demonstrated here for the case of Comet Hale-Bopp. The abundance ratio of the two isomers, hydrogen cyanide and hydrogen isocyanide, is shown to vary with heliocentric distance in a way that is consistent with production of HNC by ion-molecule chemistry initiated by the photoionization of water. Likewise, the first maps of emission from HCO+ show an abundance and an extended distribution that are consistent with the same chemical model.

  18. Bioorthogonal Chemistry-Introduction and Overview.

    PubMed

    Carell, Thomas; Vrabel, Milan

    2016-02-01

    Bioorthogonal chemistry has emerged as a new powerful tool that facilitates the study of structure and function of biomolecules in their native environment. A wide variety of bioorthogonal reactions that can proceed selectively and efficiently under physiologically relevant conditions are now available. The common features of these chemical reactions include: fast kinetics, tolerance to aqueous environment, high selectivity and compatibility with naturally occurring functional groups. The design and development of new chemical transformations in this direction is an important step to meet the growing demands of chemical biology. This chapter aims to introduce the reader to the field by providing an overview on general principles and strategies used in bioorthogonal chemistry. Special emphasis is given to cycloaddition reactions, namely to 1,3-dipolar cycloadditions and Diels-Alder reactions, as chemical transformations that play a predominant role in modern bioconjugation chemistry. The recent advances have established these reactions as an invaluable tool in modern bioorthogonal chemistry. The key aspects of the methodology as well as future outlooks in the field are discussed. PMID:27572992

  19. The Chemistry of Fragrances: A Group Exercise for Chemistry Students.

    ERIC Educational Resources Information Center

    Duprey, Roger; Sell, Charles S.; Lowe, Nigel D.

    2003-01-01

    Presents Fragrance Structured Learning Packages (SLPs), group activities designed to help students recognize the value of applying chemistry in a real-world setting. Developed by the Department of Chemistry at the University of York. (Author/KHR)

  20. Epoxying Isoprene Chemistry

    EPA Science Inventory

    It seems that every few months we read about another missing aspect of atmospheric chemistry: missing products, missing reactivity, missing sources, missing understanding. Thus, it is with some relief that we read in this issue the paper of Paulot et al. The paper provides more...

  1. Chemistry of Meridiani Outcrops

    NASA Technical Reports Server (NTRS)

    Clark, B. C.; Squyres, S. W.; Ming, D. W.; Morris, R. V.; Yen, A.; Gellert, R.; Knoll, A.H.; Arvidson, R. E.

    2006-01-01

    The chemistry and mineralogy of the sulfate-rich sandstone outcrops at Meridiani Planum, Mars, have been inferred from data obtained by the Opportunity rover of the MER mission and reported in recent publications [1-6]. Here, we provide an update on more recent samples and results derived from this extensive data set.

  2. Array processors in chemistry

    SciTech Connect

    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.

  3. Water Chemistry Laboratory Manual.

    ERIC Educational Resources Information Center

    Jenkins, David; And Others

    This manual of laboratory experiments in water chemistry serves a dual function of illustrating fundamental chemical principles of dilute aqueous systems and of providing the student with some familiarity with the chemical measurements commonly used in water and wastewater analysis. Experiments are grouped in categories on the basis of similar…

  4. Chemistry in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Henning, Thomas; Semenov, Dmitry

    2013-12-01

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

  5. Chemistry in the Troposphere.

    ERIC Educational Resources Information Center

    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. Online Organic Chemistry

    ERIC Educational Resources Information Center

    Janowicz, Philip A.

    2010-01-01

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

  7. Chemistry in a Nutshell.

    ERIC Educational Resources Information Center

    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)

  8. SMIP Chemistry Curriculum Guides.

    ERIC Educational Resources Information Center

    Wilkes Coll., Wilkes-Barre, PA.

    Included are most guides for a one-year course in senior high school chemistry. The guides may be interchanged at the teacher's discretion, following any text sequence or course outline. Each guide consists of six sections: (1) an approach, which briefly discusses the unit in terms of background material, pitfalls to be avoided, and suggested…

  9. Chemistry Cook-Off

    ERIC Educational Resources Information Center

    McCormick, Cynthia

    2012-01-01

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

  10. Analytical Chemistry Laboratory

    NASA Technical Reports Server (NTRS)

    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.

  11. Green chemistry metrics

    EPA Science Inventory

    Synthetic chemists have always had an objective to achieve reliable and high-yielding routes to the syntheses of targeted molecules. The importance of minimal waste generation has emphasized the use of green chemistry principles and sustainable development. These directions lead ...

  12. Chemistry on the Web.

    ERIC Educational Resources Information Center

    Mounts, Richard D.

    1996-01-01

    Gives an overview of the World Wide Web, describes what is required to access it, and highlights some of the features of interest to chemists such as Web-based chemical databases that feature user-interactive molecular structures and chemical movies. Lists Internet chemistry resources designed for Web browsers and locations for obtaining Web…

  13. Metaphorical Models in Chemistry.

    ERIC Educational Resources Information Center

    Rosenfeld, Stuart; Bhusan, Nalini

    1995-01-01

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

  14. Evaluating Environmental Chemistry Textbooks.

    ERIC Educational Resources Information Center

    Hites, Ronald A.

    2001-01-01

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

  15. Getting Reactions to Chemistry.

    ERIC Educational Resources Information Center

    Smith, Walter S.

    1983-01-01

    "COMETS on Careers" describes science-related careers, introduces activities illustrating a science concept being studied, and encourages use of professional persons as activity leaders. Several COMETS chemistry activities are described. These activities, which can be performed in school or at home, focus on colloids, acid/base indicators, and…

  16. The Pimlico Chemistry Trail.

    ERIC Educational Resources Information Center

    Borrows, Peter

    1984-01-01

    Describes a chemistry "trail" (similar to a nature trail) which focuses on chemical phenomena in the environment. The trail includes 20 stops in and around a local school. Types of phenomena examined include building materials, air pollution, corrosion of metals, swimming pools, and others. Additional activities are also suggested. (DH)

  17. General Chemistry, 1970 Edition.

    ERIC Educational Resources Information Center

    Dunham, Orson W.; Franke, Douglas C.

    This publication is a syllabus for a senior high school chemistry course designed for the average ability, nonscience major. The content of the syllabus is divided into three basic core areas: Area I: Similarities and Dissimilarities of Matter (9 weeks); Area II: Preparation and Separation of Substances (10 weeks); Area III: Structure and…

  18. Chemistry between the stars

    NASA Technical Reports Server (NTRS)

    Gammon, R. H.

    1976-01-01

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

  19. Nobel Prize in Chemistry

    NASA Astrophysics Data System (ADS)

    2000-01-01

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

  20. Chemistry Between The Stars.

    ERIC Educational Resources Information Center

    Gammon, Richard H.

    This booklet is part of an American Astronomical Society curriculum project designed to provide teaching materials to teachers of secondary school chemistry, physics, and earth science. The following topics are covered: the physical conditions in interstellar space in comparison with those of the earth, particularly in regard to gas density,…

  1. The Chemistry of Health

    ERIC Educational Resources Information Center

    Davis, Alison

    2009-01-01

    Do people realize that chemistry plays a key role in helping solve some of the most serious problems facing the world today? Chemists want to find the building blocks of the chemical universe--the molecules that form materials, living cells and whole organisms. Many chemists are medical explorers looking for new ways to maintain and improve…

  2. Greener and Sustainable Chemistry

    EPA Science Inventory

    The special issue on Greener and Sustainable Chemistry highlights various strategies that can be adopted to address the pollution preventive measures promoting the use of energy efficient reactions that utilize benign and bio-renewable raw materials in a relatively safer reaction...

  3. Get Cooking with Chemistry!

    ERIC Educational Resources Information Center

    American Chemical Society, Washington, DC.

    This book presents science activities investigating the chemical changes and reactions with powders that are used in baking. Activities include: (1) Mystery Powders; (2) Find the Fizz: Discover the Secret of Baking Powder; and (3) A Feast for Yeast and Cheese: Behold the Power of Chemistry. (YDS)

  4. Chemistry and Heritage

    NASA Astrophysics Data System (ADS)

    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.

  5. The Lens of Chemistry

    ERIC Educational Resources Information Center

    Thalos, Mariam

    2013-01-01

    Chemistry possesses a distinctive theoretical lens--a distinctive set of theoretical concerns regarding the dynamics and transformations of a perplexing variety of organic and nonorganic substances--to which it must be faithful. Even if it is true that chemical facts bear a special (reductive) relationship to physical facts, nonetheless it will…

  6. Microscale Gas Chemistry

    ERIC Educational Resources Information Center

    Mattson, Bruce; Anderson, Michael P.

    2011-01-01

    The development of syringes having free movement while remaining gas-tight enabled methods in chemistry to be changed. Successfully containing and measuring volumes of gas without the need to trap them using liquids made it possible to work with smaller quantities. The invention of the LuerLok syringe cap also allowed the gas to be stored for a…

  7. The Language of Chemistry.

    ERIC Educational Resources Information Center

    Bretz, Stacey Lowery; Meinwald, Jerrold

    2002-01-01

    Describes a new curriculum called The Language of Chemistry designed to illustrate how problems of biological and/or medical importance can be understood on a molecular basis and to show that the logic, knowledge, and language needed are easily accessible. Among the case studies in the curriculum are the giant peacock moth, bacterial chemotaxis,…

  8. Turkish Prospective Chemistry Teachers' Beliefs about Chemistry Teaching

    ERIC Educational Resources Information Center

    Boz, Yezdan; Uzuntiryaki, Esen

    2006-01-01

    In order to study the beliefs of Turkish prospective chemistry teachers about teaching chemistry, semi-structured interviews were conducted with 12 prospective teachers. Analysis of the interviews revealed that most of the prospective teachers held intermediate (transition between constructivist and traditional) beliefs about chemistry teaching.…

  9. Is Chemistry Attractive for Pupils? Czech Pupils' Perception of Chemistry

    ERIC Educational Resources Information Center

    Kubiatko, Milan

    2015-01-01

    Chemistry is an important subject due to understanding the composition and structure of the things around us. The main aim of the study was to find out the perception of chemistry by lower secondary school pupils. The partial aims were to find out the influence of gender, year of study and favorite subject on the perception of chemistry. The…

  10. Emphasizing Mineral Chemistry in an Analytical Chemistry Unit.

    ERIC Educational Resources Information Center

    Dunn, Jeffrey G.; And Others

    1995-01-01

    Describes an analytical chemistry unit in the second year of the chemistry degree course at Curtin University that was designed to reflect the numerous employment opportunities for chemistry graduates in the mineral processing industries and private analytical laboratories. Presents the lecture syllabus, the laboratory course description, and…

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

    ERIC Educational Resources Information Center

    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…

  12. Organic Chemistry Self Instructional Package 1: Review of General Chemistry.

    ERIC Educational Resources Information Center

    Zdravkovich, V.

    This booklet is one of a series of 17 developed at Prince George's Community College, Largo, Maryland. It provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The entire…

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

    ERIC Educational Resources Information Center

    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…

  14. Special Report: Chemistry of Comets.

    ERIC Educational Resources Information Center

    A'Hearn, Michael F.

    1984-01-01

    Discusses the chemistry of comets. How comets provide clues to the birth of the solar system, photolytic reactions on comets involving water, chemical modeling, nuclear chemistry, and research findings are among the areas considered. (JN)

  15. The Lighter Side of Chemistry.

    ERIC Educational Resources Information Center

    Lamb, William G.

    1984-01-01

    Discusses the rationale for using photochemistry to merge descriptive chemistry and molecular orbital theory in first-year chemistry courses. Includes procedures and safety information for various activities, demonstrations, and experiments involving photochemical reactions. (DH)

  16. The Birthday of Organic Chemistry.

    ERIC Educational Resources Information Center

    Benfey, Otto Theodor; Kaufman, George B.

    1979-01-01

    Describes how the synthesis of urea, 150 years ago, was a major factor in breaking the artificial barrier that existed between organic and inorganic chemistry, and this contributed to the rapid growth of organic chemistry. (GA)

  17. The Status of General Chemistry

    ERIC Educational Resources Information Center

    Brooks, David W.

    1977-01-01

    Presents the first of a series of papers discussing the major features and underlying philosophies of general college chemistry. This first paper reviews secondary level course content as well as college level general chemistry curricula. (SL)

  18. Chemistry 200, 300 Interim Guide.

    ERIC Educational Resources Information Center

    Manitoba Dept. of Education, Winnipeg.

    This guide, developed for the chemistry 200, 300 program in Manitoba, is designed to articulate with previous science courses, provide concepts, processes, and skills which will enable students to continue in chemistry-related areas, and relate chemistry to practical applications in everyday life. It includes a program overview (with program goals…

  19. Predictors of General Chemistry Grades.

    ERIC Educational Resources Information Center

    Ozsogomonyan, Ardas; Loftus, Drew

    1979-01-01

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

  20. Six Pillars of Organic Chemistry

    ERIC Educational Resources Information Center

    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…

  1. Creating a Research-Rich Chemistry Curriculum with an Integrated, Upper-Level-Undergraduate Laboratory Program

    ERIC Educational Resources Information Center

    Gron, Liz U.; Hales, David A.; Teague, M. Warfield

    2007-01-01

    A new research-rich chemistry curriculum with an integrated, upper-level undergraduate laboratory program has recently been developed to impart better understanding to the students. The program is called Advanced techniques in Experimental Chemistry and helps prepare students for more real-world problems.

  2. Understanding and Using the New Guided-Inquiry AP Chemistry Laboratory Manual

    ERIC Educational Resources Information Center

    Cacciatore, Kristen L.

    2014-01-01

    To support teaching and learning in the advanced placement (AP) chemistry laboratory, the College Board published a laboratory manual, "AP Chemistry Guided-Inquiry Experiments: Applying the Science Practices," in 2013 as part of the redesigned course. This article provides a discussion of the rationale for the existence of the manual as…

  3. Context-Based and Conventional Approaches to Teaching Chemistry: Comparing Teachers' Views

    ERIC Educational Resources Information Center

    Bennett, Judith; Grasel, Cornelia; Parchmann, Ilka; Waddington, David

    2005-01-01

    The study explores teachers' experiences of teaching a context-based chemistry course, "Salters Advanced Chemistry", as compared with teachers of a conventional course. Second, main factors that appear to influence decisions over whether or not to adopt context-based courses are investigated. Two hundred and twenty-two teachers' views of a…

  4. Professional Development Aligned with AP Chemistry Curriculum: Promoting Science Practices and Facilitating Enduring Conceptual Understanding

    ERIC Educational Resources Information Center

    Herrington, Deborah G.; Yezierski, Ellen J.

    2014-01-01

    The recent revisions to the advanced placement (AP) chemistry curriculum promote deep conceptual understanding of chemistry content over more rote memorization of facts and algorithmic problem solving. For many teachers, this will mean moving away from traditional worksheets and verification lab activities that they have used to address the vast…

  5. Past, Present, and Future of AP Chemistry: A Brief History of Course and Exam Alignment Efforts

    ERIC Educational Resources Information Center

    Magrogan, Serena

    2014-01-01

    As part of the Advanced Placement (AP) Program's commitment to continually enhance alignment with current best practices in college-level learning, the AP Program is currently evaluating and redesigning courses and exams, one of which launched during the 2013-2014 academic school year: AP chemistry. The history of the AP chemistry course and…

  6. High School Chemistry Students' Scientific Epistemologies and Perceptions of the Nature of Laboratory Inquiry

    ERIC Educational Resources Information Center

    Vhurumuku, Elaosi

    2011-01-01

    This quantitative study investigated the relationship between Chemistry students' scientific epistemologies and their perceptions of the nature of laboratory inquiry. Seventy-two Advanced Level Chemistry students were surveyed. The students were sampled from twelve schools in three of Zimbabwe's nine administrative provinces. Students' scientific…

  7. Determination of Heats of Fusion: Using Differential Scanning Calorimetry for the AP Chemistry Courses.

    ERIC Educational Resources Information Center

    Temme, Susan M.

    1995-01-01

    Describes an exercise designed to be used in an Advanced Placement (AP) chemistry course to accompany the study of thermodynamics. Uses Differential Scanning Calorimetry in teaching the concepts of thermochemistry and thermodynamics. (JRH)

  8. Entry to neptunyl(V) chemistry in anhydrous systems

    SciTech Connect

    Copping, Roy; Berthon, Claude; Moisy, Philippe; Den Auwer, Christophe

    2012-08-15

    The increasing generation of highly radioactive neptunium during nuclear power production has called for an enhanced understanding of the fundamental chemistry of this element. NpO{sub 2}{sup +}, Np(V) is the most relevant neptunyl species in both nuclear reprocessing, environmental concerns and long-term storage of waste where {sup 237}Np represents a significant component of radiotoxicity. A fundamental understanding of the structure, bonding and reactivity of this species is essential for the development of advanced future {sup 237}Np separation processes. Therefore it is important that neptunyl(V) coordination chemistry is advanced to anaerobic systems where air and moisture sensitive ligands containing softer donor atoms can be utilized. To achieve this we have developed an anhydrous Np(V) synthetic precursor and begun to probe coordination chemistry with multi-dentate Schiff base ligands. (authors)

  9. Click Chemistry-Mediated Nanosensors for Biochemical Assays

    PubMed Central

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanoprobes based on click chemistry. Nanoprobes including gold nanoparticles, quantum dots, magnetic nanoparticles and carbon nanomaterials are covered. We discuss the advantages of click chemistry-mediated nanosensors for biochemical assays, and give perspectives on the development of click chemistry-mediated approaches for clinical diagnosis and other biomedical applications. PMID:27217831

  10. Click Chemistry-Mediated Nanosensors for Biochemical Assays.

    PubMed

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanoprobes based on click chemistry. Nanoprobes including gold nanoparticles, quantum dots, magnetic nanoparticles and carbon nanomaterials are covered. We discuss the advantages of click chemistry-mediated nanosensors for biochemical assays, and give perspectives on the development of click chemistry-mediated approaches for clinical diagnosis and other biomedical applications. PMID:27217831

  11. The chemistry of curcumin: from extraction to therapeutic agent.

    PubMed

    Priyadarsini, Kavirayani Indira

    2014-01-01

    Curcumin, a pigment from turmeric, is one of the very few promising natural products that has been extensively investigated by researchers from both the biological and chemical point of view. While there are several reviews on the biological and pharmacological effects of curcumin, chemistry reviews are comparatively scarcer. In this article, an overview of different aspects of the unique chemistry research on curcumin will be discussed. These include methods for the extraction from turmeric, laboratory synthesis methods, chemical and photochemical degradation and the chemistry behind its metabolism. Additionally other chemical reactions that have biological relevance like nucleophilic addition reactions, and metal chelation will be discussed. Recent advances in the preparation of new curcumin nanoconjugates with metal and metal oxide nanoparticles will also be mentioned. Directions for future investigations to be undertaken in the chemistry of curcumin have also been suggested. PMID:25470276

  12. Density Functional Theory in Surface Chemistry and Catalysis

    SciTech Connect

    Norskov, Jens

    2011-05-19

    Recent advances in the understanding of reactivity trends for chemistry at transition metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. Current status of the field is discussed with an emphasis on the role of coupling between theory and experiment and future challenges.

  13. Mathematics in Chemistry: Indeterminate Forms and Their Meaning

    ERIC Educational Resources Information Center

    Segurado, Manuel A. P.; Silva, Margarida F. B.; Castro, Rita

    2011-01-01

    The mathematical language and its tools are complementary to the formalism in chemistry, in particular at an advanced level. It is thus crucial, for its understanding, that students acquire a solid knowledge in Calculus and that they know how to apply it. The frequent occurrence of indeterminate forms in multiple areas, particularly in Physical…

  14. College Chemistry Students' Mental Models of Acids and Acid Strength

    ERIC Educational Resources Information Center

    McClary, LaKeisha; Talanquer, Vicente

    2011-01-01

    The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…

  15. Contributions of Analytical Chemistry to the Clinical Laboratory.

    ERIC Educational Resources Information Center

    Skogerboe, Kristen J.

    1988-01-01

    Highlights several analytical techniques that are being used in state-of-the-art clinical labs. Illustrates how other advances in instrumentation may contribute to clinical chemistry in the future. Topics include: biosensors, polarization spectroscopy, chemiluminescence, fluorescence, photothermal deflection, and chromatography in clinical…

  16. The New AP Chemistry Exam: Its Rationale, Content, and Scoring

    ERIC Educational Resources Information Center

    Price, Paul D.; Kugel, Roger W.

    2014-01-01

    The 2013-2014 academic year marks the rollout of the redesigned advanced placement (AP) chemistry course and exam. There have been many questions as to why the course was redesigned and how the new examination will differ from its legacy version. In this article we give a brief overview of the legacy course and examine why a redesign occurred in…

  17. An Experimental Introduction to Interlaboratory Exercises in Analytical Chemistry

    ERIC Educational Resources Information Center

    Puignou, L.; Llaurado, M.

    2005-01-01

    An experimental exercise on analytical proficiency studies in collaborative trials is proposed. This practical provides students in advanced undergraduate courses in chemistry, pharmacy, and biochemistry, with the opportunity to improve their quality assurance skills. It involves an environmental analysis, determining the concentration of a…

  18. Density functional theory in surface chemistry and catalysis

    PubMed Central

    Nørskov, Jens K.; Abild-Pedersen, Frank; Studt, Felix; Bligaard, Thomas

    2011-01-01

    Recent advances in the understanding of reactivity trends for chemistry at transition-metal surfaces have enabled in silico design of heterogeneous catalysts in a few cases. The current status of the field is discussed with an emphasis on the role of coupling theory and experiment and future challenges. PMID:21220337

  19. Theoretical Chemistry Comes Alive: Full Partner with Experiment.

    ERIC Educational Resources Information Center

    Goddard, William A., III

    1985-01-01

    The expected thrust for theoretical chemistry in the next decade will be to combine knowledge of fundamental chemical steps/interactions with advances in chemical dynamics, irreversible statistical mechanics, and computer technology to produce simulations of chemical systems with reaction site competition. A sample simulation (using the enzyme…

  20. Introduction to Atmospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Thompson, Anne M.

    In thirty years of university teaching, Peter Hobbs of the Atmospheric Sciences Department at the University of Washington, has seen atmospheric chemistry grow from a relatively small branch of geosciences into one with which every student of atmospheric sciences needs familiarity Some students are captivated in their first course and make atmospheric chemistry a field of further study or a lifelong career. At the same time, courses of “global change” and emerging curricula in scientific policy require students from diverse backgrounds to develop sufficient knowledge to become well-informed policy-makers. A number of practicing atmospheric chemists are retrained on the job from other scientific backgrounds and need selfeducation in the basics of the field.

  1. [Gaubius and medical chemistry].

    PubMed

    van Gijn, Jan; Gijselhart, Joost P

    2011-01-01

    Hieronymus David Gaub (1705-1780) was the son of a protestant cloth merchant in Heidelberg. Disliking a pietistic boarding school in Halle, Germany, he came to stay with a paternal uncle who was a physician in Amsterdam. Hieronymus studied medicine in Harderwijk and in Leiden, under the guidance of Herman Boerhaave (1668-1738). In 1731 he was appointed reader (and in 1734 professor) in chemistry at the Leiden medical faculty. After Boerhaave's death he also taught medicine, but without access to hospital beds. Gaubius correctly envisaged that chemistry would become an important discipline in medicine, but was limited by the technical constraints of his time. In his textbook of general pathology (1758) he attributed disease to disturbances of not only fluids, but also solid parts, although symptoms remained the basis of his classification. The book would remain influential for several decades, until the advent of pathological anatomy. PMID:22217241

  2. Turbine Chemistry Modeling

    NASA Technical Reports Server (NTRS)

    Liu, Nan-Suey; Wey, Thomas

    2001-01-01

    Many of the engine exhaust species resulting in significant environmental impact exist in trace amounts. Recent research, e.g., conducted at MIT-AM, has pointed to the intra-engine environment as a possible site for important trace chemistry activity. In addition, the key processes affecting the trace species activity occurring downstream in the air passages of the turbine and exhaust nozzle are not well understood. Most recently, an effort has been initiated at NASA Glenn Research Center under the UEET Program to evaluate and further develop CFD-based technology for modeling and simulation of intra-engine trace chemical changes relevant to atmospheric effects of pollutant emissions from aircraft engines. This presentation will describe the current effort conducted at Glenn; some preliminary results relevant to the trace species chemistry in a turbine passage will also be presented to indicate the progress to date.

  3. Muons in chemistry

    NASA Astrophysics Data System (ADS)

    Clayden, N. J.

    2013-12-01

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

  4. Chemistry in protoplanetary disks

    NASA Astrophysics Data System (ADS)

    Semenov, D. A.

    2012-01-01

    In this lecture I discuss recent progress in the understanding of the chemical evolution of protoplanetary disks that resemble our Solar system during the first ten million years. At the verge of planet formation, strong variations of temperature, density, and radiation intensities in these disks lead to a layered chemical structure. In hot, dilute and heavily irradiated atmosphere only simple radicals, atoms, and atomic ions can survive, formed and destroyed by gas-phase processes. Beneath the atmosphere a partly UV-shielded, warm molecular layer is located, where high-energy radiation drives rich chemistry, both in the gas phase and on dust surfaces. In a cold, dense, dark disk midplane many molecules are frozen out, forming thick icy mantles where surface chemistry is active and where complex (organic) species are synthesized.

  5. Heterogeneous atmospheric chemistry

    NASA Technical Reports Server (NTRS)

    Schryer, D. R.

    1982-01-01

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

  6. Organic Chemistry in Space

    NASA Technical Reports Server (NTRS)

    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.

  7. Fenton chemistry: an introduction.

    PubMed

    Wardman, P; Candeias, L P

    1996-05-01

    In 1876, Fenton described a colored product obtained on mixing tartaric acid with hydrogen peroxide and a low concentration of a ferrous salt. Full papers in 1894 and 1896 showed the product was dihydroxymaleic acid. Haber, Weiss and Willstätter proposed in 1932-1934 the involvement of free hydroxyl radicals in the iron(II)/hydrogen peroxide system, and Baxendale and colleagues around 1950 suggested that superoxide reduces the iron(III) formed on reaction, explaining the catalytic nature of the metal. Since Fridovich and colleagues discovered the importance of superoxide dismutase in 1968, numerous studies have sought to explain the deleterious effects of cellular oxidative stress in terms of superoxide-driven Fenton chemistry. There remain questions concerning the involvement of free hydroxyl radicals or reactions of metal/oxo intermediates. However, these outstanding questions may obscure a wider appreciation of the importance of Fenton chemistry involving hypohalous acids rather than hydrogen peroxide as the oxidant. PMID:8619017

  8. Nuclear analytical chemistry

    SciTech Connect

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

    1984-01-01

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

  9. Quo vadis, analytical chemistry?

    PubMed

    Valcárcel, Miguel

    2016-01-01

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

  10. Atmospheric Chemistry Data Products

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This presentation poster covers data products from the Distributed Active Archive Center (DAAC) of the Goddard Earth Sciences (GES) Data and Information Services Center (DISC). Total Ozone Mapping Spectrometer products (TOMS) introduced in the presentation include TOMS Version 8 as well as Aura, which provides 25 years of TOMS and Upper Atmosphere Research Satellite (UARS) data. The presentation lists a number of atmospheric chemistry and dynamics data sets at DAAC.

  11. Wet chemistry instrument prototype

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A wet chemistry instrument prototype for detecting amino acids in planetary soil samples was developed. The importance of amino acids and their condensation products to the development of life forms is explained. The characteristics of the instrument and the tests which were conducted to determine the materials compatibility are described. Diagrams are provided to show the construction of the instrument. Data obtained from the performance tests are reported.

  12. Green chemistry: development trajectory

    NASA Astrophysics Data System (ADS)

    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.

  13. A review of mesospheric dynamics and chemistry

    SciTech Connect

    Viereck, R.A. )

    1991-01-01

    Advances made in understanding the chemistry and dynamics of the atmosphere in the approximate altitude range of 50 to 90 km are addressed. Attention is given to mesospheric structure and seasonal variations, gravity waves and gravity wave saturation, the effects of gravity waves on thermal, momentum and constituent fluxes, and the effect of gravity waves on airglow emissions. A review of research on tides and planetary waves and their effects on the mesosphere are presented as well as discussions on ozone hydroxyl, water vapor, and noctilucent cloud research. 217 refs.

  14. Chemistry, life, and the search for aliens

    NASA Astrophysics Data System (ADS)

    Benner, Steven A.

    2010-09-01

    While "life" may universally be a self-sustaining chemical system capable of Darwinian evolution, alien life may be quite different in its chemistry from the terran life that we know here on Earth. In this case, it will be difficult to recognize, especially if it has not advanced beyond the single cell life forms that have dominated much of the terran biosphere. This review summarizes what we might infer from general physical and chemical law about how such "weird" life might be structured, what solvents other than water it might inhabit, what genetic molecules it might contain, and what metabolism it might exploit.

  15. Chemistry of sex attraction.

    PubMed Central

    Roelofs, W L

    1995-01-01

    The chemical communication system used to attract mates involves not only the overt chemical signals but also indirectly a great deal of chemistry in the emitter and receiver. As an example, in emitting female moths, this includes enzymes (and cofactors, mRNA, genes) of the pheromone biosynthetic pathways, hormones (and genes) involved in controlling pheromone production, receptors and second messengers for the hormones, and host plant cues that control release of the hormone. In receiving male moths, this includes the chemistry of pheromone transportation in antennal olfactory hairs (binding proteins and sensillar esterases) and the chemistry of signal transduction, which includes specific dendritic pheromone receptors and a rapid inositol triphosphate second messenger signal. A fluctuating plume structure is an integral part of the signal since the antennal receptors need intermittent stimulation to sustain upwind flight. Input from the hundreds of thousands of sensory cells is processed and integrated with other modalities in the central nervous system, but many unknown factors modulate the information before it is fed to motor neurons for behavioral responses. An unknown brain control center for pheromone perception is discussed relative to data from behavioral-threshold studies showing modulation by biogenic amines, such as octopamine and serotonin, from genetic studies on pheromone discrimination, and from behavioral and electrophysiological studies with behavioral antagonists. Images Fig. 1 PMID:7816846

  16. Extensible Computational Chemistry Environment

    2012-08-09

    ECCE provides a sophisticated graphical user interface, scientific visualization tools, and the underlying data management framework enabling scientists to efficiently set up calculations and store, retrieve, and analyze the rapidly growing volumes of data produced by computational chemistry studies. ECCE was conceived as part of the Environmental Molecular Sciences Laboratory construction to solve the problem of researchers being able to effectively utilize complex computational chemistry codes and massively parallel high performance compute resources. Bringing themore » power of these codes and resources to the desktops of researcher and thus enabling world class research without users needing a detailed understanding of the inner workings of either the theoretical codes or the supercomputers needed to run them was a grand challenge problem in the original version of the EMSL. ECCE allows collaboration among researchers using a web-based data repository where the inputs and results for all calculations done within ECCE are organized. ECCE is a first of kind end-to-end problem solving environment for all phases of computational chemistry research: setting up calculations with sophisticated GUI and direct manipulation visualization tools, submitting and monitoring calculations on remote high performance supercomputers without having to be familiar with the details of using these compute resources, and performing results visualization and analysis including creating publication quality images. ECCE is a suite of tightly integrated applications that are employed as the user moves through the modeling process.« less

  17. Chemistry of electronic ceramic materials. Proceedings of the International Conference on the Chemistry of Electronic Ceramic Materials

    NASA Technical Reports Server (NTRS)

    Davies, P. K.; Roth, R. S.

    1991-01-01

    The conference was held at Jackson Hole, Wyoming from August 17 to 22, 1990, and in an attempt to maximize the development of this rapidly moving, multidisciplinary field, this conference brought together major national and international researchers to bridge the gap between those primarily interested in the pure chemistry of inorganic solids and those interested in the physical and electronic properties of ceramics. With the many major discoveries that have occurred over the last decade, one of the goals of this meeting was to evaluate the current understanding of the chemistry of electronic ceramic materials, and to assess the state of a field that has become one of the most important areas of advanced materials research. The topics covered include: crystal chemistry; dielectric ceramics; low temperature synthesis and characterization; solid state synthesis and characterization; surface chemistry; superconductors; theory and modeling.

  18. Chemistry Perfumes Your Daily Life

    NASA Astrophysics Data System (ADS)

    Fortineau, Anne-Dominique

    2004-01-01

    The use of perfumes can be tracked back to many early civilizations. Historically, perfumes were composed exclusively of natural ingredients, mainly essential oils, and were reserved for the wealthiest people. The use of synthetic ingredients marked the beginning of modern perfumery at the end of the 19th century. Nowadays, perfumes are available to everyone and are present in a wide range of consumer goods. The methods used to extract perfume ingredients from their natural sources have changed over time as technology has advanced. Depending on the material, expression, distillation, and solvent extraction are the main techniques used to extract the odorant components from a natural source. Synthetic organic chemistry has provided perfumers with novel ingredients that are cheaper and more stable than many natural materials over the years. Today, more than 3000 fragrance ingredients are estimated to be available to perfumers to create a harmonious composition of head (for example, citrusy), heart (for example, fruity floral) and base notes (for example, musky). Future developments and uses of perfume are endless and as Ernest Beaux, the perfumer who created Chanel N85, once said, "In perfumery the future lies primarily in the hands of the chemists." Featured on the Cover See Featured Molecules .

  19. Towards "Bildung"-Oriented Chemistry Education

    ERIC Educational Resources Information Center

    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…

  20. Recycling of Advanced Batteries for Electric Vehicles

    SciTech Connect

    JUNGST,RUDOLPH G.

    1999-10-06

    The pace of development and fielding of electric vehicles is briefly described and the principal advanced battery chemistries expected to be used in the EV application are identified as Ni/MH in the near term and Li-ion/Li-polymer in the intermediate to long term. The status of recycling process development is reviewed for each of the two chemistries and future research needs are discussed.

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

    NASA Astrophysics Data System (ADS)

    Versprille, Ashley N.

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

  2. Heterogeneous Chemistry in Global Chemistry Transport Models

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

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

  3. Discovering chemistry with an ab initio nanoreactor

    NASA Astrophysics Data System (ADS)

    Martinez, Todd

    Traditional approaches for modeling chemical reaction networks such as those involved in combustion have focused on identifying individual reactions and using theoretical approaches to explore the underlying mechanisms. Recent advances involving graphical processing units (GPUs), commodity products developed for the videogaming industry, have made it possible to consider a distinct approach wherein one attempts to discover chemical reactions and mechanisms. We provide a brief summary of these developments and then discuss the concept behind the ``ab initio nanoreactor'' which explores the space of possible chemical reactions and molecular species for a given stoichiometry. The nanoreactor concept is exemplified with an example to the Urey-Miller reaction network which has been previously advanced as a potential model for prebiotic chemistry. We briefly discuss some of the future directions envisioned for the development of this nanoreactor concept.

  4. Tropospheric Halogen Chemistry

    NASA Astrophysics Data System (ADS)

    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

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

    SciTech Connect

    Heiken, J.H.

    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.

  6. Mars aqueous chemistry experiment

    NASA Technical Reports Server (NTRS)

    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.

  7. Dynamic foldamer chemistry.

    PubMed

    Le Bailly, Bryden A F; Clayden, Jonathan

    2016-04-01

    Foldamers can be made more than pieces of static, conformationally uniform molecular architecture by designing into their structure the conformational dynamism characteristic of functional molecular machines. We show that these dynamic foldamers display biomimetic properties reminiscent of allosteric proteins and receptor molecules. They can translate chemical signals into conformational changes, and hence into chemical outputs such as control of reactivity and selectivity. Future developments could see dynamic foldamers operating in the membrane phase providing artificial mechanisms for communication and control that integrate synthetic chemistry into synthetic biology. PMID:26955864

  8. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of the analytical procedure of NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL can determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  9. Phoenix's Wet Chemistry Lab

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This is an illustration of soil analysis on NASA's Phoenix Mars Lander's Wet Chemistry Lab (WCL) on board the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) instrument. By dissolving small amounts of soil in water, WCL will attempt to determine the pH, the abundance of minerals such as magnesium and sodium cations or chloride, bromide and sulfate anions, as well as the conductivity and redox potential.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  10. Extended Wordsearches in Chemistry

    NASA Astrophysics Data System (ADS)

    Cotton, Simon

    1998-04-01

    Students can be encouraged to develop their factual knowledge by use of puzzles. One strategy described here is the extended wordsearch, where the wordsearch element generates a number of words or phrases from which the answers to a series of questions are selected. The wordsearch can be generated with the aid of computer programs, though in order to make them suitable for students with dyslexia or other learning difficulties, a simpler form is more appropriate. These problems can be employed in a variety of contexts, for example, as topic tests and classroom end-of-lesson fillers. An example is provided in the area of calcium chemistry. Sources of suitable software are listed.

  11. Solvents and sustainable chemistry

    PubMed Central

    Welton, Tom

    2015-01-01

    Solvents are widely recognized to be of great environmental concern. The reduction of their use is one of the most important aims of green chemistry. In addition to this, the appropriate selection of solvent for a process can greatly improve the sustainability of a chemical production process. There has also been extensive research into the application of so-called green solvents, such as ionic liquids and supercritical fluids. However, most examples of solvent technologies that give improved sustainability come from the application of well-established solvents. It is also apparent that the successful implementation of environmentally sustainable processes must be accompanied by improvements in commercial performance. PMID:26730217

  12. Chemistry and Science Fiction

    NASA Astrophysics Data System (ADS)

    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.

  13. Problems of space chemistry

    NASA Astrophysics Data System (ADS)

    Voitkevich, Georgii V.

    The main problems of space chemistry are examined, including the origin and abundance of chemical elements, their migration to different regions of the universe, the formation of the chemical composition of cosmic bodies, and the chemical evolution of the solar system and the origin of life. Based on current astrophysical and space-chemical data, the main stages of the evolution of matter from the beginning of universe expansion to the formation of the solar system are described. The problem of the origin of life is examined in the light of space-chemical data on the formation of high-molecular compounds before the formation of the planets.

  14. Environmental Chemistry Update

    NASA Astrophysics Data System (ADS)

    1995-08-01

    111 pg, leading to a body fat concentration of about 40 ppt (12). Lithium Battery AdvancesRechargeable Power SourceRecent advances in lithium ion battery technology may allow these devices to become the rechargeable power source of choice in electric cars of the future. Due to their high voltage, they can store a large amount of energy per given mass or volume of battery. In the past, however, such batteries have been somewhat impractical because they had to be hermetically sealed and required nonaqueous electrolytes due to lithium's violent reaction with water. In the newly developed battery, the electrolyte is water that already contains a high concentration of Li+ ions; elemental lithium (present as LiMn2O4 in one electrode) is unreactive in this medium unless an external connection to the other electrode is made (13). Air-Pollution Control for Power PlantsA process called SNOX, which removes both NOx and SO2 from the flue gases produced by coal-fired power plants, has been developed and demonstrated. The nitrogen oxides are first reduced to N2. The resulting gas is then heated and catalytically oxidized to sulfur trioxide, which is then hydrated to sulfuric acid. More than 90% of the NOx and SO2 were removed from the flue gases in the demonstration held at an Ohio Edison plant (14). Literature Cited Williams, D. Nature 1994, 371, 556. Emsley, J. New Scientist 1994, (Oct 1), 14. McMichael, A. J. American Journal of Epidemiology 1994, 140, 489-499. Chemical and Engineering News 1994, (Oct 10), 5. Santee, M. L. Science 1995, 267, 849-852. Chemical and Engineering News 1994, (Nov 14). Solomon, S. Journal of Geophysical Research 1994, 99, 20491-20499. Wennberg, P. O. Science 1994, 266, 398-404. Viggiano, A. A. Science 1995, 267, 82-84. Summary in Chemistry and Engineering News 1995, (Jan 9), 23. Schottler, S. P.; Eisenreich, S. J. Environmental Science and Technology 1994, 28, 2228-2232. Lang, L. Environmental Health Perspectives 1993, 101, 578-583. Chemical and

  15. HARNESSING THE CHEMISTRY OF CO2

    SciTech Connect

    Louie, Janis

    2010-05-11

    Our research program is broadly focused on activating CO{sub 2} through the use of organic and organometallic based catalysts. Some of our methods have centered on annulation reactions of unsaturated hydrocarbons (and carbonyl substrates) to provide a diverse array of carbocycles and heterocycles. We use a combination of catalyst discovery and optimization in conjunction with classical physical organic chemistry to elucidate the key mechanistic features of the cycloaddition reactions such that the next big advances in catalyst development can be made. Key to all of our cycloaddition reactions is the use of a sterically hindered, electron donating N heterocyclic carbene (NHC) ligand, namely IPr (or SIPr), in conjunction with a low valent nickel pre-catalyst. The efficacy of this ligand is two-fold: (1) the high {delta}-donating ability of the NHC increases the nucleophilicity of the metal center which thereby facilitates interaction with the electrophilic carbonyl and (2) the steric hindrance prevents an otherwise competitive side reaction involving only the alkyne substrate. Such a system has allowed for the facile cycloaddition to prepare highly functionalized pyrones, pyridones, pyrans, as well as novel carbocycles. Importantly, all reactions proceed under extremely mild conditions (room temperature, atmospheric pressures, and short reaction times), require only catalytic amounts of Ni/NHC and readily available starting materials, and afford annulated products in excellent yields. Our current focus revolves around understanding the fundamental processes that govern these cycloadditions such that the next big advance in the cyclization chemistry of CO{sub 2} can be made. Concurrent to our annulation chemistry is our investigation of the potential for imidazolylidenes to function as thermally-actuated CO{sub 2} sequestering and delivery agents.

  16. Complex Protostellar Chemistry

    NASA Technical Reports Server (NTRS)

    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.

  17. Interstellar Grain Surface Chemistry

    NASA Technical Reports Server (NTRS)

    Tielens, Alexander G. G. M.; Cuzzi, Jeffrey N. (Technical Monitor)

    1995-01-01

    Chemistry on grain surfaces plays an Important role in the formation of interstellar Ices, It can also influence the composition of the gas phase through outgassing near luminous, newly formed stars. This paper reviews the chemical processes taking place on Interstellar grain surfaces with the emphasis on those transforming CO into other hydrocarbons. At low, molecular cloud temperatures (approximately equal to 10K), physisorption processes dominate interstellar grain surface chemistry and GO is largely hydrogenated through reactions with atomic H and oxidized through reactions with atomic O. The former will lead to the formation of H2CO and CH3OH ices, while the latter results in CO2 ice. The observational evidence for these ices in molecular clouds will be discussed. Very close to protostars, the gas and grain temperatures are much higher (approximately equal to 500K) and chemisorption processes, including catalytic surface reactions, becomes important. This will be illustrated based upon our studies of the Fischer-Tropsch Synthesis of CH4 from CO on metallic surfaces. Likely, this process has played an important role in the early solar nebula. Observational consequences will be pointed out.

  18. Graduate Education in Environmental Chemistry

    ERIC Educational Resources Information Center

    Lee, G. Fred

    1974-01-01

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

  19. Cross-Connections of Chemistry

    NASA Astrophysics Data System (ADS)

    Mason, Diana S.

    2002-02-01

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

  20. An introduction to the Advanced Testing Line for Actinide Separations (ATLAS)

    SciTech Connect

    Pope, N.G.; Yarbro, S.L.; Schreiber, S.B.; Day, R.S.

    1992-03-01

    The Advanced Testing Line for Actinide Separations (ATLAS) will evaluate promising plutonium recovery process modifications and new technologies. It combines advances in process chemistry, process control, process analytical chemistry, and process engineering. ATLAS has a processing capability equal to other recovery systems but without the pressure to achieve predetermined recovery quotas.

  1. A New Chemistry Course for Non-Chemistry Majors.

    ERIC Educational Resources Information Center

    Ariel, Magda; And Others

    1982-01-01

    A two-semester basic chemistry course for nonchemistry engineering majors is described. First semester provides introductory chemistry for freshmen while second semester is "customer-oriented," based on a departmental choice of three out of six independent modules. For example, aeronautical engineering "customers" would select kinetics, organic…

  2. Influencing College Chemistry Success through High School Chemistry Teaching

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  3. Art in Chemistry: Chemistry in Art. Second Edition

    ERIC Educational Resources Information Center

    Greenberg, Barbara R.; Patterson, Dianne

    2008-01-01

    This textbook integrates chemistry and art with hands-on activities and fascinating demonstrations that enable students to see and understand how the science of chemistry is involved in the creation of art. It investigates such topics as color integrated with electromagnetic radiation, atoms, and ions; paints integrated with classes of matter,…

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  5. An Exhibition on Everyday Chemistry. Communicating Chemistry to the Public.

    ERIC Educational Resources Information Center

    Ucko, David A.; And Others

    1986-01-01

    Discusses a recent addition to the Museum of Science and Industry (Chicago) known as "Everyday Chemistry." This permanent exhibit on modern chemistry incorporates demonstrations of chemical reactions in ways intended to enhance public understanding. Describes the six cases in the exhibit and the automated aspects of their demonstrations. (TW)

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

    PubMed

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

    2015-01-01

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

  7. Amyloid cascade in Alzheimer's disease: Recent advances in medicinal chemistry.

    PubMed

    Mohamed, Tarek; Shakeri, Arash; Rao, Praveen P N

    2016-05-01

    Alzheimer's disease is of major concern all over the world due to a number of factors including (i) an aging population (ii) increasing life span and (iii) lack of effective pharmacotherapy options. The past decade has seen intense research in discovering disease-modifying multitargeting small molecules as therapeutic options. The pathophysiology of Alzheimer's disease is attributed to a number of factors such as the cholinergic dysfunction, amyloid/tau toxicity and oxidative stress/mitochondrial dysfunction. In recent years, targeting the amyloid cascade has emerged as an attractive strategy to discover novel neurotherapeutics. Formation of beta-amyloid species, with different degrees of solubility and neurotoxicity is associated with the gradual decline in cognition leading to dementia. The two commonly used approaches to prevent beta-amyloid accumulation in the brain include (i) development of beta-secretase inhibitors and (ii) designing direct inhibitors of beta-amyloid (self-induced) aggregation. This review highlights the amyloid cascade hypothesis and the key chemical features required to design small molecules that inhibit lower and higher order beta-amyloid aggregates. Several recent examples of small synthetic molecules with disease-modifying properties were considered and their molecular docking studies were conducted using either a dimer or steric-zipper assembly of beta-amyloid. These investigations provide a mechanistic understanding on the structural requirements needed to design novel small molecules with anti-amyloid aggregation properties. Significantly, this work also demonstrates that the structural requirements to prevent aggregation of various amyloid species differs considerably, which explains the fact that many small molecules do not exhibit similar inhibition profile toward diverse amyloid species such as dimers, trimers, tetramers, oligomers, protofibrils and fibrils. PMID:26945113

  8. Overview of the advances in environmental chemistry of animal manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is an increasing environmental concern over animal manure due to the volumes produced in modern intensified animal production. However, animal manure is traditionally regarded as a valuable resource of plant nutrients. Although research on environmental impacts of animal manure and associated...

  9. Advances in the chemistry of monocyclic amino- and nitrofuroxans

    NASA Astrophysics Data System (ADS)

    Makhova, N. N.; Kulikov, A. S.

    2013-11-01

    The review summarizes data on the development of methods of synthesis and reactivity of monocyclic amino- and nitrofuroxans published in the last 20-25 years. The details of the synthesis of aminofuroxans based on the Schmidt and Curtius rearrangements involving acetyl- and azidocarbonylfuroxans, respectively, are discussed. Specific features of the transformations of functional substituents in aminofuroxans are described. In consideration of the reactivity of aminofuroxans, the attention is focused on the oxidation, diazotization and the Mannich reaction. Methods of synthesis of nitrofuroxans based on the oxidation of nitroglyoximes and the nitrosation of unsaturated compounds and dipotassium salts of 2-substituted 2-hydroxyimino-1,1-dinitroethanes are covered. The reactivity of nitrofuroxans comprises the nucleophilic substitution, reduction and thermal furoxan ring opening to form nitrile oxides. The bibliography includes 111 references.

  10. Recent advances in the chemistry of positron emitters

    SciTech Connect

    Wolf, A.P.; Fowler, J.S.

    1985-01-01

    With the increasing active interest in PET as a method for studying biochemistry in normal and pathological states in humans we can expect to see the development of new techniques for precursor preparation and synthesis. We have seen a doubling of the publication rate in the past three to four years over the previous three to four year period. As the need for these compounds, especially in the tumor and receptor areas, in a purely clinical setting, increases the trend towards true automation of production of the most needeed compounds will accelerate. The cyclotron manufacturers all offer ''black boxes'' for synthesis but the optimum approach to user friendly automation yet needs to be defined. I would note that this paper was not intended as a comprehensive review but rather my goal was to highlight just some of the exciting developments of the past several years. We are entering what may well be the most extensive and active period of research in the synthesis of positron emitter labeled compounds. If 1984 to 1985 is any gauge, many new methods and compounds will appear in the next several years. 37 refs.

  11. Separating the Minor Actinides Through Advances in Selective Coordination Chemistry

    SciTech Connect

    Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Carter, Jennifer C.

    2012-08-22

    This report describes work conducted at the Pacific Northwest National Laboratory (PNNL) in Fiscal Year (FY) 2012 under the auspices of the Sigma Team for Minor Actinide Separation, funded by the U.S. Department of Energy Office of Nuclear Energy. Researchers at PNNL and Argonne National Laboratory (ANL) are investigating a simplified solvent extraction system for providing a single-step process to separate the minor actinide elements from acidic high-level liquid waste (HLW), including separating the minor actinides from the lanthanide fission products.

  12. Significant advancement of mass spectrometry imaging for food chemistry.

    PubMed

    Yoshimura, Yukihiro; Goto-Inoue, Naoko; Moriyama, Tatsuya; Zaima, Nobuhiro

    2016-11-01

    Food contains various compounds that have an impact on our daily lives. Many technologies have been established to analyze these molecules of interest in foods. However, the analysis of the spatial distribution of these compounds in foods using conventional technology, such as high-performance liquid chromatography-mass spectrometry or gas chromatography-mass spectrometry is difficult. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is considered an ideal complementary approach. MALDI-MSI is a two-dimensional MALDI-MS technology that can detect compounds in a tissue section without extraction, purification, separation, or labeling. MALDI-MSI can be used to visualize the spatial distribution of chemical compounds or biomolecules in foods. Although the methodology of MALDI-MSI in food science is not yet fully established, the versatility of MALDI-MSI is expected to open a new frontier in food science. Herein, we describe the principles and applications of MALDI-MSI in food science and related fields. PMID:27211639

  13. Getting Hooked on Chemistry

    NASA Astrophysics Data System (ADS)

    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!

  14. Frontiers in polymer chemistry.

    PubMed

    Schlüter, A Dieter

    2013-01-01

    The article shows how the initial concept of Staudinger on linear macromolecules was expanded topologically by increasing the cross-section diameter of polymer chains and by introducing sheet polymers with planar rather than the commonly known linear repeat units. The two concrete projects addressed are the synthesis of dendronized and of two-dimensional polymers. It is explained how these novel macromolecules were achieved and which obstacles had to be overcome but also where these frontiers in polymer chemistry might lead to new insights in polymer science in general and novel applications in particular. The article also provides insights into analytical issues because both target macromolecules are in an extraordinarily high molar mass range and contrast/sensitivity issues can turn rather serious in particular for the two-dimensional polymers. PMID:24388233

  15. Organic chemistry on Titan

    NASA Technical Reports Server (NTRS)

    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.

  16. Prebiotic phosphorus chemistry reconsidered

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  17. Nanoplasmonics tuned "click chemistry".

    PubMed

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

    2016-04-01

    Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised "click" reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the "click" chemistry. PMID:26961136

  18. Atmospheric Pseudohalogen Chemistry

    NASA Technical Reports Server (NTRS)

    Lary, David John

    2004-01-01

    Hydrogen cyanide is not usually considered in atmospheric chemical models. The paper presents three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. Firstly, HCN is a product and marker of biomass burning. Secondly, it is also likely that lightning is producing HCN, and as HCN is sparingly soluble it could be a useful long-lived "smoking gun" marker of lightning activity. Thirdly, the chemical decomposition of HCN leads to the production of small amounts of the cyanide (CN) and NCO radicals. The NCO radical can be photolyzed in the visible portion of the spectrum yielding nitrogen atoms (N). The production of nitrogen atoms is significant as it leads to the titration of total nitrogen from the atmosphere via N+N->N2, where N2 is molecular nitrogen.

  19. Chemistry and Special Education

    NASA Astrophysics Data System (ADS)

    Riendl, Pamela A.; Haworth, Daniel T.

    1995-11-01

    Secondary and post-secondary science teachers are beginning to see increasing numbers of students with mild disabilities enrolled in their classes. These students can be classified as having one of a variety of mild disabilities that might impact the way they receive and process educational information. As a result of the passage in 1975 of PL 94-142, the Individuals with Disabilities Act (IDEA), disabled students now have the opportunity to receive special education in the public schools and to be placed in regular classrooms whenever possible. Very little information for science teachers is provided in teacher preparation courses or is available in the literature to offer concrete suggestions for teaching science to these students. This paper describes the political gains made in education for the disabled, identifies various types of mild disabilities, and suggests possible teaching interventions for the chemistry teacher who has a student with a mild disability.

  20. Prebiotic chemistry in clouds

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  1. Chemistry of Aviation Fuels

    NASA Technical Reports Server (NTRS)

    Knepper, Bryan; Hwang, Soon Muk; DeWitt, Kenneth J.

    2004-01-01

    Minimum ignition energies of various methanol/air mixtures were measured in a temperature controlled constant volume combustion vessel using a spark ignition method with a spark gap distance of 2 mm. The minimum ignition energies decrease rapidly as the mixture composition (equivalence ratio, Phi) changes from lean to stoichiometric, reach a minimum value, and then increase rather slowly with Phi. The minimum of the minimum ignition energy (MIE) and the corresponding mixture composition were determined to be 0.137 mJ and Phi = 1.16, a slightly rich mixture. The variation of minimum ignition energy with respect to the mixture composition is explained in terms of changes in reaction chemistry.

  2. Clays in prebiological chemistry

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  3. Nanoplasmonics tuned ``click chemistry''

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

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

  4. Silane discharge ion chemistry

    SciTech Connect

    Chatham, R.H. III

    1984-01-01

    Silane dc, rf, and dc proximity discharges have been studied using mass spectroscopic measurements of the positive ions as a detailed diagnostic for the type of discharge used to produce hydrogenated amorphous silicon solar photovoltaic cells. The properties and quality of these films depends in a very complex way upon the interactions of the many reactive neutral and ion species in the discharge. Qualitative models of the ion chemical processes in these discharges have been developed from experimental measurements. Knowledge of the ion-molecule and electron-molecule collision cross sections is important to any attempt at understanding silane discharge chemistry. Consequently, the electron impact ionization cross sections for silane and disilane have been measured and for comparison purposes also for methane and ethane. In addition, the rate coefficients for charge exchange reactions of He , Ne , and Ar with silane, disilane, methane, and ethane have been measured as these are important to understanding discharges in inert gas-silane mixtures. A detailed quantitative model of the cathode sheath region of a silane dc discharge has been developed by extending the best recent calculation of the electron motion in the sheath to a self-consistent form which includes the ion motion. This model is used with comparison of silane dc discharge data to diagnose the ion chemistry occurring in the sheath region of silane dc discharge. The understanding of the discharge ion chemical processes that have been gained in this study represent an important step toward understanding the chemical and physical processes leading to film growth.

  5. Turbulent Mixing Chemistry in Disks

    NASA Astrophysics Data System (ADS)

    Semenov, D.; Wiebe, D.

    2006-11-01

    A gas-grain chemical model with surface reaction and 1D/2D turbulent mixing is available for protoplanetary disks and molecular clouds. Current version is based on the updated UMIST'95 database with gas-grain interactions (accretion, desorption, photoevaporation, etc.) and modified rate equation approach to surface chemistry (see also abstract for the static chemistry code).

  6. Contextualising Nanotechnology in Chemistry Education

    ERIC Educational Resources Information Center

    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…

  7. Stereochemical Control in Carbohydrate Chemistry

    ERIC Educational Resources Information Center

    Batchelor, Rhys; Northcote, Peter T.; Harvey, Joanne E.; Dangerfield, Emma M.; Stocker, Bridget L.

    2008-01-01

    Carbohydrates, in the form of glycoconjugates, have recently been shown to control a wide range of cellular processes. Accordingly, students interested in the study of organic chemistry and biomedical sciences should be exposed to carbohydrate chemistry. To this end, we have developed a sequence of experiments that leads the student from the…

  8. Local Evaluation of Chemistry Journals

    ERIC Educational Resources Information Center

    Kraus, Joseph R.; Hansen, Rachel

    2008-01-01

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

  9. Chemical Principles Revisited: Petroleum Chemistry.

    ERIC Educational Resources Information Center

    Kolb, Doris; Kolb, Kenneth E.

    1979-01-01

    Presents an historical review of the role of petroleum in world history and information on the chemistry of petroleum. It is suggested that petroleum chemistry be discussed since within the next two decades oil and gas will provide the major portion of U.S. energy. (Author/SA)

  10. Chemistry Teachers' Views of Creativity

    ERIC Educational Resources Information Center

    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…

  11. Introducing Relativity into Quantum Chemistry

    ERIC Educational Resources Information Center

    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…

  12. A Cooperative Chemistry Project: Chemsource.

    ERIC Educational Resources Information Center

    Giles, Catherine Y.

    1994-01-01

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

  13. Plasma chemistry and its applications

    NASA Technical Reports Server (NTRS)

    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).

  14. Chemistry laboratory safety manual available

    NASA Technical Reports Server (NTRS)

    Elsbrock, R. G.

    1968-01-01

    Chemistry laboratory safety manual outlines safe practices for handling hazardous chemicals and chemistry laboratory equipment. Included are discussions of chemical hazards relating to fire, health, explosion, safety equipment and procedures for certain laboratory techniques and manipulations involving glassware, vacuum equipment, acids, bases, and volatile solvents.

  15. Fundamentals of Aqueous Microwave Chemistry

    EPA Science Inventory

    The first chemical revolution changed modern life with a host of excellent amenities and services, but created serious problems related to environmental pollution. After 150 years of current chemistry principles and practices, we need a radical change to a new type of chemistry k...

  16. The Great Ideas of Chemistry.

    ERIC Educational Resources Information Center

    Gillespie, Ronald J.

    1997-01-01

    Presents a list of six concepts that form the basis of modern chemistry and that should be included in introductory chemistry courses. Discusses atoms, molecules, and ions; the chemical bond; molecular shape and geometry; kinetic theory; the chemical reaction; and energy and entropy. (JRH)

  17. Organic Chemistry for the Gifted.

    ERIC Educational Resources Information Center

    deBeer, W. H. J.

    In response to a serious shortage of chemists in South Africa, gifted secondary school students are enrolled in an enrichment program in organic chemistry and encouraged to consider chemistry or one of its related fields as a career. The introductory portion of the program involves approximately 90 hours over a 3-year period while the advanced…

  18. Remedial Mathematics for Quantum Chemistry

    ERIC Educational Resources Information Center

    Koopman, Lodewijk; Brouwer, Natasa; Heck, Andre; Buma, Wybren Jan

    2008-01-01

    Proper mathematical skills are important for every science course and mathematics-intensive chemistry courses rely on a sound mathematical pre-knowledge. In the first-year quantum chemistry course at this university, it was noticed that many students lack basic mathematical knowledge. To tackle the mathematics problem, a remedial mathematics…

  19. Crocodile Chemistry. [CD-ROM].

    ERIC Educational Resources Information Center

    1999

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

  20. News from Online: Green Chemistry

    ERIC Educational Resources Information Center

    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.

  1. Advance directives

    PubMed Central

    O’Sullivan, Rory; Mailo, Kevin; Angeles, Ricardo; Agarwal, Gina

    2015-01-01

    Abstract Objective To establish the prevalence of patients with advance directives in a family practice, and to describe patients’ perspectives on a family doctor’s role in initiating discussions about advance directives. Design A self-administered patient questionnaire. Setting A busy urban family medicine teaching clinic in Hamilton, Ont. Participants A convenience sample of adult patients attending the clinic over the course of a typical business week. Main outcome measures The prevalence of advance directives in the patient population was determined, and the patients’ expectations regarding the role of their family doctors were elucidated. Results The survey population consisted of 800 participants (a response rate of 72.5%) well distributed across age groups; 19.7% had written advance directives and 43.8% had previously discussed the topic of advance directives, but only 4.3% of these discussions had occurred with family doctors. In 5.7% of cases, a family physician had raised the issue; 72.3% of respondents believed patients should initiate the discussion. Patients who considered advance directives extremely important were significantly more likely to want their family doctors to start the conversation (odds ratio 3.98; P < .05). Conclusion Advance directives were not routinely addressed in the family practice. Most patients preferred to initiate the discussion of advance directives. However, patients who considered the subject extremely important wanted their family doctors to initiate the discussion. PMID:25873704

  2. Chemistry of Art and Color Sudoku Puzzles

    ERIC Educational Resources Information Center

    Welsh, Michael J.

    2007-01-01

    Sudoku puzzle format was used to teach light science and chemistry terms to students of Chemistry of Art and Color. The puzzles were used to motivate and encourage students to learn chemistry in an easier and in friendly fashion.

  3. A Multistep Synthesis Featuring Classic Carbonyl Chemistry for the Advanced Organic Chemistry Laboratory

    ERIC Educational Resources Information Center

    Duff, David B.; Abbe, Tyler G.; Goess, Brian C.

    2012-01-01

    A multistep synthesis of 5-isopropyl-1,3-cyclohexanedione is carried out from three commodity chemicals. The sequence involves an aldol condensation, Dieckmann-type annulation, ester hydrolysis, and decarboxylation. No purification is required until after the final step, at which point gravity column chromatography provides the desired product in…

  4. Lincoln Advanced Science & Engineering Reinforcement (LASER) Program.

    ERIC Educational Resources Information Center

    Williams, Willie

    The Lincoln Advanced Science and Engineering Reinforcement (LASER) Program at Lincoln University, which has recruited over 100 students for majors in technical fields, is described in this report. To date, over 70% have completed or will complete technical degrees in engineering, physics, chemistry, and computer science. Of those completing the…

  5. Interactions between dynamics and chemistry by COMMA modeling

    NASA Astrophysics Data System (ADS)

    Berger, U.; Koerner, U.; Sonnemann, G.

    Much of our current knowledge of the chemistry and circulation of the middle atmosphere derives from the spacecraft instruments since the the late 1970s (LIMS, SAGE II, ATMOS) and in particular the 1990s (HALOE, MLS, MAS, ILAS POAM III). In parallel , knowledge of the global circulation has continued to advance thanks to rapid developments in theoretical studies performed using numerical general circulation models (GCMs). This paper will focus on the upper atmosphere at polar latitudes because this region is of special importance for climate studies where trace gases like carbon dioxide, water vapor, ozone, etc. are key ingredients in determing the thermal structure of the summer high latitude mesopause region. Both processes, chemistry as well as dynamical induced transports, and their numerical description define the quality criterions of Middle Atmosphere GCMs. Due to comparisons of modeled and observed trace gas distributions (time scale season down to hours) we will discuss recent advance in numerical modeling of the MLT region.

  6. Incorporation of Medicinal Chemistry into the Organic Chemistry Curriculum

    ERIC Educational Resources Information Center

    Forbes, David C.

    2004-01-01

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

  7. Chemistry behind Vegetarianism.

    PubMed

    Li, Duo

    2011-02-01

    This review summarizes the effect of a habitual vegetarian diet on clinical complications in relation to chemistry and biochemistry. Omnivores have a significantly higher cluster of cardiovascular risk factors compared with vegetarians, including increased body mass index, waist to hip ratio, blood pressure, plasma total cholesterol (TC), triacylglycerol and LDL-C levels, serum lipoprotein(a) concentration, plasma factor VII activity, ratios of TC/HDL-C, LDL-C/HDL-C and TAG/HDL-C, and serum ferritin levels. Compared with omnivores, vegetarians, especially vegans, have lower serum vitamin B₁₂ concentration and n-3 polyunsaturated fatty acid (PUFA) levels in the tissue membrane phospholipids, which are associated with increased collagen and ADP stimulated ex vivo whole blood platelet aggregation, plasma 11-dehydrothromboxane B₂, and homocysteine levels and decreased plasma HDL-C. This may be associated with an increased thrombotic and atherosclerotic risk. It is suggested that vegetarians, especially vegans, should increase their dietary n-3 PUFA and vitamin B₁₂ intakes. PMID:21204526

  8. Chemistry in one dimension.

    PubMed

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

    2015-02-01

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

  9. Exoplanet Equilibrium Chemistry Calculations

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

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

  10. Organic chemistry on Titan

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

    Observations of nonequilibrium phenomena on the Saturn satellite Titan indicate the occurrence of organic chemical evolution. Greenhouse and thermal inversion models of Titan's atmosphere provide environmental constraints within which various pathways for organic chemical synthesis are assessed. Experimental results and theoretical modeling studies suggest that the organic chemistry of the satellite may be dominated by two atmospheric processes: energetic-particle bombardment and photochemistry. Reactions initiated in various levels of the atmosphere by cosmic ray, Saturn wind, and solar wind particle bombardment of a CH4 - N2 atmospheric mixture can account for the C2-hydrocarbons, the UV-visible-absorbing stratospheric haze, and the reddish color of the satellite. Photochemical reactions of CH4 can also account for the presence of C2-hydrocarbons. In the lower Titan atmosphere, photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. Hot H-atom reactions initiated by photo-dissociation of NH3 can couple the chemical reactions of NH3 and CH4 and produce organic matter.

  11. Mars aqueous chemistry experiment

    NASA Technical Reports Server (NTRS)

    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.

  12. Cometary MHD and chemistry

    NASA Technical Reports Server (NTRS)

    Wegmann, R.; Schmidt, H. U.; Huebner, W. F.; Boice, D. C.

    1987-01-01

    An MHD and chemical comet-coma model was developed, applying the computer program of Huebner (1985) for the detailed chemical evolution of a spherically expanding coma and the program of Schmidt and Wegman (1982) and Wegman (1987) for the MHD flow of plasma and magnetic field in a comet to the Giotto-mission data on the ion abundances measured by the HIS ion mass spectrometer. The physics and chemistry of the coma are modeled in great detail, including photoprocesses, gas-phase chemical kinetics, energy balance with a separate electron temperature, multifluid hydrodynamics with a transition to free molecular flow, fast-streaming atomic and molecular hydrogen, counter and cross streaming of the ionized species relative to the neutral species in the coma-solar wind interaction region with momentum exchange by elastic collisions, mass-loading through ion pick-up, and Lorentz forces of the advected magnetic field. The results, both inside and outside of the contact surface, are discussed and compared with the relevant HIS ion mass spectra.

  13. Marine fragrance chemistry.

    PubMed

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

    2008-06-01

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

  14. Nuclear chemistry progress report

    SciTech Connect

    Viola, V.E.; Kwiatkowski, K.

    1993-08-01

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

  15. Perceptions of coordinators of college freshman chemistry regarding selected goals and outcomes of high school chemistry

    NASA Astrophysics Data System (ADS)

    Shumba, Overson; Glass, Lynn W.

    Several studies have shown that high school science teachers base their teaching on what professors of college freshman science expect, and that, in some instances, advanced high school courses are needlessly similar to college freshman courses. In order to gain insight of college science professors' expectations and perceptions on selected goals and outcomes of science education, a survey instrument was developed and mailed to 123 heads/coordinators of freshman chemistry in U.S. state and land grant colleges and universities that offer a graduate degree program in chemistry. The results demonstrated that although the coordinators were positive about many science education goals and outcomes they did not value aspects related to societal issues, and no differences among them existed when the results were analyzed according to demographic subgroups such as age and teaching experience. They perceived high school graduates as possessing inadequate skills and perceived measures to improve precollege science education requiring collaboration of precollege and college faculty positively. The implications for science education were that college chemistry professors place values different from those of science educators on some pertinent goals and outcomes of science teaching, a situation that is not helpful to reforming precollege science education.

  16. Cryogenic ion chemistry and spectroscopy.

    PubMed

    Wolk, Arron B; Leavitt, Christopher M; Garand, Etienne; Johnson, Mark A

    2014-01-21

    The use of mass spectrometry in macromolecular analysis is an incredibly important technique and has allowed efficient identification of secondary and tertiary protein structures. Over 20 years ago, Chemistry Nobelist John Fenn and co-workers revolutionized mass spectrometry by developing ways to non-destructively extract large molecules directly from solution into the gas phase. This advance, in turn, enabled rapid sequencing of biopolymers through tandem mass spectrometry at the heart of the burgeoning field of proteomics. In this Account, we discuss how cryogenic cooling, mass selection, and reactive processing together provide a powerful way to characterize ion structures as well as rationally synthesize labile reaction intermediates. This is accomplished by first cooling the ions close to 10 K and condensing onto them weakly bound, chemically inert small molecules or rare gas atoms. This assembly can then be used as a medium in which to quench reactive encounters by rapid evaporation of the adducts, as well as provide a universal means for acquiring highly resolved vibrational action spectra of the embedded species by photoinduced mass loss. Moreover, the spectroscopic measurements can be obtained with readily available, broadly tunable pulsed infrared lasers because absorption of a single photon is sufficient to induce evaporation. We discuss the implementation of these methods with a new type of hybrid photofragmentation mass spectrometer involving two stages of mass selection with two laser excitation regions interfaced to the cryogenic ion source. We illustrate several capabilities of the cryogenic ion spectrometer by presenting recent applications to peptides, a biomimetic catalyst, a large antibiotic molecule (vancomycin), and reaction intermediates pertinent to the chemistry of the ionosphere. First, we demonstrate how site-specific isotopic substitution can be used to identify bands due to local functional groups in a protonated tripeptide designed to

  17. Teaching Chemistry with Electron Density Models

    NASA Astrophysics Data System (ADS)

    Shusterman, Gwendolyn P.; Shusterman, Alan J.

    1997-07-01

    Linus Pauling once said that a topic must satisfy two criteria before it can be taught to students. First, students must be able to assimilate the topic within a reasonable amount of time. Second, the topic must be relevant to the educational needs and interests of the students. Unfortunately, the standard general chemistry textbook presentation of "electronic structure theory", set as it is in the language of molecular orbitals, has a difficult time satisfying either criterion. Many of the quantum mechanical aspects of molecular orbitals are too difficult for most beginning students to appreciate, much less master, and the few applications that are presented in the typical textbook are too limited in scope to excite much student interest. This article describes a powerful new method for teaching students about electronic structure and its relevance to chemical phenomena. This method, which we have developed and used for several years in general chemistry (G.P.S.) and organic chemistry (A.J.S.) courses, relies on computer-generated three-dimensional models of electron density distributions, and largely satisfies Pauling's two criteria. Students find electron density models easy to understand and use, and because these models are easily applied to a broad range of topics, they successfully convey to students the importance of electronic structure. In addition, when students finally learn about orbital concepts they are better prepared because they already have a well-developed three-dimensional picture of electronic structure to fall back on. We note in this regard that the types of models we use have found widespread, rigorous application in chemical research (1, 2), so students who understand and use electron density models do not need to "unlearn" anything before progressing to more advanced theories.

  18. Superspace crystallography: a key to the chemistry and properties

    PubMed Central

    Pinheiro, Carlos Basílio; Abakumov, Artem M.

    2015-01-01

    An overview is given of the recent advances in the field of modulated molecular and inorganic crystals with an emphasis on the links between incommensurability, intermolecular and interatomic interactions and, wherever possible, the properties of the materials. The importance of detailed knowledge on the modulated structure for understanding the crystal chemistry and the functional properties of modulated phases is shown using selected examples of incommensurate modulations in organic molecular compounds and inorganic complex oxides. PMID:25610634

  19. Chemistry and Materials Science, 1990--1991. [Second annual report

    SciTech Connect

    Sugihara, T.T.; Bruner, J.M.; McElroy, L.A.

    1991-12-31

    This 2-year (FY 1990-91) contains 49 technical articles in ten sections: research sampler, metals and alloys, energetic materials, chemistry and physics of advanced materials, bonding and reactions at surfaces and interfaces, superconductivity, energy R and D, waste processing and management, characterization and analysis, and facilities and instrumentation. Two more sections list department personnel, their publications etc., consultants, and summary of department budgets. The articles are processed separately for the data base. (DLC)

  20. Advanced Microsensors

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This video looks at a spinoff application of the technology from advanced microsensors -- those that monitor and determine conditions of spacecraft like the Space Shuttle. The application featured is concerned with the monitoring of the health of premature babies.

  1. Radiation Chemistry and Photochemistry of Ionic Liquids

    SciTech Connect

    Wishart, J.F.; Takahaski, K.

    2010-12-01

    As our understanding of ionic liquids and their tunable properties has grown, it is possible to see many opportunities for ionic liquids to contribute to the sustainable use of energy. The potential safety and environmental benefits of ionic liquids, as compared to conventional solvents, have attracted interest in their use as processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiation and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. This article provides a brief introduction to ionic liquids and their interesting properties, and recent advances in the radiation chemistry and photochemistry of ionic liquids. In this article, we will mainly focus on excess electron dynamics and radical reaction dynamics. Because solvation dynamics processes in ionic liquids are much slower than in molecular solvents, one of the distinguishing characteristics is that pre-solvated electrons play an important role in ionic liquid radiolysis. It will be also shown that the reaction dynamics of radical ions is significantly different from that observed in molecular solvents because of the Coulombic screening effects and electrostatic interactions in ionic liquids.

  2. Recent progress in actinide borate chemistry

    SciTech Connect

    Wang, Shuao; Alekseev, Evgeny V.; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.

    2011-01-01

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB₅O₆(OH)₆][BO(OH)₂]·2.5H₂O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO4- Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials.

  3. Submillimeter Planetary Atmospheric Chemistry Exploration Sounder

    NASA Technical Reports Server (NTRS)

    Schlecht, Erich T.; Allen, Mark A.; Gill, John J.; Choonsup, Lee; Lin, Robert H.; Sin, Seth; Mehdi, Imran; Siegel, Peter H.; Maestrini, Alain

    2013-01-01

    Planetary Atmospheric Chemistry Exploration Sounder (SPACES), a high-sensitivity laboratory breadboard for a spectrometer targeted at orbital planetary atmospheric analysis. The frequency range is 520 to 590 GHz, with a target noise temperature sensitivity of 2,500 K for detecting water, sulfur compounds, carbon compounds, and other atmospheric constituents. SPACES is a prototype for a powerful tool for the exploration of the chemistry and dynamics of any planetary atmosphere. It is fundamentally a single-pixel receiver for spectral signals emitted by the relevant constituents, intended to be fed by a fixed or movable telescope/antenna. Its front-end sensor translates the received signal down to the 100-MHz range where it can be digitized and the data transferred to a spectrum analyzer for processing, spectrum generation, and accumulation. The individual microwave and submillimeter wave components (mixers, LO high-powered amplifiers, and multipliers) of SPACES were developed in cooperation with other programs, although with this type of instrument in mind. Compared to previous planetary and Earth science instruments, its broad bandwidth (approx. =.13%) and rapid tunability (approx. =.10 ms) are new developments only made possible recently by the advancement in submillimeter circuit design and processing at JPL.

  4. Recent progress in actinide borate chemistry.

    PubMed

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-10-21

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB(5)O(6)(OH)(6)][BO(OH)(2)]·2.5H(2)O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO(4)(-). Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials. PMID:21915396

  5. Cure Chemistry of Phenylethynyl Terminated Oligomers

    NASA Technical Reports Server (NTRS)

    Wood, Karen H.; Orwoll, Robert A.; Young, Philip R.; Jensen, Brian J.; McNair, Harold M.

    1997-01-01

    The ability to process high performance polymers into quality, void-free composites has been significantly advanced using oligomers terminated with reactive groups which cure or crosslink at elevated temperature without the evolution of volatile byproducts. Several matrix resin systems of considerable interest to the aerospace community utilize phenylethynyl-terminated imide (PETI) technology to achieve this advantage. The present paper addresses the cure chemistry of PETI oligomers. The thermal cure of a low molecular weight model compound was studied using a variety of analytical techniques including differential scanning calorimetry, Fourier transform infrared spectroscopy, and liquid chromatography-mass spectroscopy. The studies indicate an extremely complex cure process. Many stable products were isolated and this paper reports current work on identification of those products. The intent of this research is to provide fundamental insight into the molecular structure of the cured PETI engineering materials so that performance and durability can be more fully assessed.

  6. Discovering chemistry with an ab initio nanoreactor

    DOE PAGESBeta

    Wang, Lee-Ping; Titov, Alexey; McGibbon, Robert; Liu, Fang; Pande, Vijay S.; Martínez, Todd J.

    2014-11-02

    Chemical understanding is driven by the experimental discovery of new compounds and reactivity, and is supported by theory and computation that provides detailed physical insight. While theoretical and computational studies have generally focused on specific processes or mechanistic hypotheses, recent methodological and computational advances harken the advent of their principal role in discovery. Here we report the development and application of the ab initio nanoreactor – a highly accelerated, first-principles molecular dynamics simulation of chemical reactions that discovers new molecules and mechanisms without preordained reaction coordinates or elementary steps. Using the nanoreactor we show new pathways for glycine synthesis frommore » primitive compounds proposed to exist on the early Earth, providing new insight into the classic Urey-Miller experiment. Ultimately, these results highlight the emergence of theoretical and computational chemistry as a tool for discovery in addition to its traditional role of interpreting experimental findings.« less

  7. Discovering chemistry with an ab initio nanoreactor

    PubMed Central

    Wang, Lee-Ping; Titov, Alexey; McGibbon, Robert; Liu, Fang; Pande, Vijay S.; Martínez, Todd J.

    2014-01-01

    Chemical understanding is driven by the experimental discovery of new compounds and reactivity, and is supported by theory and computation that provides detailed physical insight. While theoretical and computational studies have generally focused on specific processes or mechanistic hypotheses, recent methodological and computational advances harken the advent of their principal role in discovery. Here we report the development and application of the ab initio nanoreactor – a highly accelerated, first-principles molecular dynamics simulation of chemical reactions that discovers new molecules and mechanisms without preordained reaction coordinates or elementary steps. Using the nanoreactor we show new pathways for glycine synthesis from primitive compounds proposed to exist on the early Earth, providing new insight into the classic Urey-Miller experiment. These results highlight the emergence of theoretical and computational chemistry as a tool for discovery in addition to its traditional role of interpreting experimental findings. PMID:25411881

  8. Discovering chemistry with an ab initio nanoreactor.

    PubMed

    Wang, Lee-Ping; Titov, Alexey; McGibbon, Robert; Liu, Fang; Pande, Vijay S; Martínez, Todd J

    2014-12-01

    Chemical understanding is driven by the experimental discovery of new compounds and reactivity, and is supported by theory and computation that provide detailed physical insight. Although theoretical and computational studies have generally focused on specific processes or mechanistic hypotheses, recent methodological and computational advances harken the advent of their principal role in discovery. Here we report the development and application of the ab initio nanoreactor--a highly accelerated first-principles molecular dynamics simulation of chemical reactions that discovers new molecules and mechanisms without preordained reaction coordinates or elementary steps. Using the nanoreactor, we show new pathways for glycine synthesis from primitive compounds proposed to exist on the early Earth, which provide new insight into the classic Urey-Miller experiment. These results highlight the emergence of theoretical and computational chemistry as a tool for discovery, in addition to its traditional role of interpreting experimental findings. PMID:25411881

  9. Discovering chemistry with an ab initio nanoreactor

    NASA Astrophysics Data System (ADS)

    Wang, Lee-Ping; Titov, Alexey; McGibbon, Robert; Liu, Fang; Pande, Vijay S.; Martínez, Todd J.

    2014-12-01

    Chemical understanding is driven by the experimental discovery of new compounds and reactivity, and is supported by theory and computation that provide detailed physical insight. Although theoretical and computational studies have generally focused on specific processes or mechanistic hypotheses, recent methodological and computational advances harken the advent of their principal role in discovery. Here we report the development and application of the ab initio nanoreactor—a highly accelerated first-principles molecular dynamics simulation of chemical reactions that discovers new molecules and mechanisms without preordained reaction coordinates or elementary steps. Using the nanoreactor, we show new pathways for glycine synthesis from primitive compounds proposed to exist on the early Earth, which provide new insight into the classic Urey-Miller experiment. These results highlight the emergence of theoretical and computational chemistry as a tool for discovery, in addition to its traditional role of interpreting experimental findings.

  10. Discovering chemistry with an ab initio nanoreactor

    SciTech Connect

    Wang, Lee-Ping; Titov, Alexey; McGibbon, Robert; Liu, Fang; Pande, Vijay S.; Martínez, Todd J.

    2014-11-02

    Chemical understanding is driven by the experimental discovery of new compounds and reactivity, and is supported by theory and computation that provides detailed physical insight. While theoretical and computational studies have generally focused on specific processes or mechanistic hypotheses, recent methodological and computational advances harken the advent of their principal role in discovery. Here we report the development and application of the ab initio nanoreactor – a highly accelerated, first-principles molecular dynamics simulation of chemical reactions that discovers new molecules and mechanisms without preordained reaction coordinates or elementary steps. Using the nanoreactor we show new pathways for glycine synthesis from primitive compounds proposed to exist on the early Earth, providing new insight into the classic Urey-Miller experiment. Ultimately, these results highlight the emergence of theoretical and computational chemistry as a tool for discovery in addition to its traditional role of interpreting experimental findings.

  11. Volcanic Plume Chemistry: Models, Observations and Impacts

    NASA Astrophysics Data System (ADS)

    Roberts, Tjarda; Martin, Robert; Oppenheimer, Clive; Griffiths, Paul; Braban, Christine; Cox, Tony; Jones, Rod; Durant, Adam; Kelly, Peter

    2010-05-01

    Volcanic plumes are highly chemically reactive; both in the hot, near-vent plume, and also at ambient temperatures in the downwind plume, as the volcanic gases and aerosol disperse into the background atmosphere. In particular, DOAS (Differential Optical Absortpion Spectroscopy) observations have identified BrO (Bromine Monoxide) in several volcanic plumes degassing into the troposphere. These observations are explained by rapid in-plume autocatalytic BrO-chemistry that occurs whilst the plume disperses, enabling oxidants such as ozone from background air to mix with the acid gases and aerosol. Computer modelling tools have recently been developed to interpret the observed BrO and predict that substantial ozone depletion occurs downwind. Alongside these modelling developments, advances in in-situ and remote sensing techniques have also improved our observational understanding of volcanic plumes. We present simulations using the model, PlumeChem, that predict the spatial distribution of gases in volcanic plumes, including formation of reactive halogens BrO, ClO and OClO that are enhanced nearer the plume edges, and depletion of ozone within the plume core. The simulations also show that in-plume chemistry rapidly converts NOx into nitric acid, providing a mechanism to explain observed elevated in-plume HNO3. This highlights the importance of coupled BrO-NOx chemistry, both for BrO-formation and as a production mechanism for HNO3 in BrO-influenced regions of the atmosphere. Studies of coupled halogen-H2S-chemistry are consistent with in-situ Alphasense electrochemical sensor observations of H2S at a range of volcanoes, and only predict H2S-depletion if Cl is additionally elevated. Initial studies regarding the transformations of mercury within volcanic plumes suggest that significant in-plume conversion of Hg0 to Hg2+ can occur in the downwind plume. Such Hg2+ may impact downwind ecology through enhanced Hg-deposition, and causing enhanced biological uptake of

  12. Ozone Research with Advanced Cooperative Lidar Experiment (ORACLE) Implementation Study

    NASA Technical Reports Server (NTRS)

    Stadler, John H.; Browell, Edward V.; Ismail, Syed; Dudelzak, Alexander E.; Ball, Donald J.

    1998-01-01

    New technological advances have made possible new active remote sensing capabilities from space. Utilizing these technologies, the Ozone Research with Advanced Cooperative Lidar Experiment (ORACLE) will provide high spatial resolution measurements of ozone, clouds and aerosols in the stratosphere and lower troposphere. Simultaneous measurements of ozone, clouds and aerosols will assist in the understanding of global change, atmospheric chemistry and meteorology.

  13. What Chemistry To Teach Engineers?

    ERIC Educational Resources Information Center

    Hawkes, Stephen J.

    2000-01-01

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

  14. Chemistry Education: Experiments Worth Running

    ERIC Educational Resources Information Center

    Kirchhoff, Mary M.

    2007-01-01

    The Education system has decided to introduce various new experiments and a digital system for imparting chemistry education to children in schools. The new programs are expected to prepare graduate students completely for their professional lives beyond the graduate school.

  15. Organic Experiments for Introductory Chemistry.

    ERIC Educational Resources Information Center

    Rayner-Canham, Geoff

    1985-01-01

    Describes test-tube organic chemistry procedures (using comparatively safe reagents) for the beginning student. These procedures are used to: examine differences between saturated and unsaturated hydrocarbons; compare structural isomers; and compare organic and inorganic acids and bases. (DH)

  16. Beginning Chemistry Can Be Relevant

    ERIC Educational Resources Information Center

    Corwin, James F.

    1971-01-01

    Reviews ways of applying laboratory work in general and analytical chemistry to supermarket products. Describes ways water and air pollution analysis can illustrate acid-base reactions, redox reactions, precipitimetry, and colorimetry. (PR)

  17. Plants and Medicinal Chemistry--2

    ERIC Educational Resources Information Center

    Bailey, D.

    1977-01-01

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

  18. Can Chemistry Teachers' Centres Survive?

    ERIC Educational Resources Information Center

    Garforth, F. M.

    1972-01-01

    The difficulties faced by the Hull Chemistry Teachers' Centre in England are discussed. The lack of finances and time, as well as organizational difficulties in relationship with Science Centres and universities are among the problems. (TS)

  19. Chem I Supplement: Archaeological Chemistry.

    ERIC Educational Resources Information Center

    Lambert, Joseph B.

    1983-01-01

    Dating, conservation, prospection, and composition (knowledge of the composition of artifacts of other materials) are four applications of chemistry to archaeology. Examples of the latter application (composition) are discussed, focusing on procedures used and types of information obtained. (JN)

  20. Hot atom chemistry and radiopharmaceuticals

    SciTech Connect

    Krohn, Kenneth A.; Moerlein, Stephen M.; Link, Jeanne M.; Welch, Michael J.

    2012-12-19

    The chemical products made in a cyclotron target are a combined result of the chemical effects of the nuclear transformation that made the radioactive atom and the bulk radiolysis in the target. This review uses some well-known examples to understand how hot atom chemistry explains the primary products from a nuclear reaction and then how radiation chemistry is exploited to set up the optimal product for radiosynthesis. It also addresses the chemical effects of nuclear decay. There are important principles that are common to hot atom chemistry and radiopharmaceutical chemistry. Both emphasize short-lived radionuclides and manipulation of high specific activity nuclides. Furthermore, they both rely on radiochromatographic separation for identification of no-carrieradded products.

  1. Analytical Chemistry: A Literary Approach.

    ERIC Educational Resources Information Center

    Lucy, Charles A.

    2000-01-01

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

  2. Chemistry in the Justice System.

    ERIC Educational Resources Information Center

    Hazdra, James J.

    1980-01-01

    The application of chemistry to the justice system is presented. The role of the forensic chemist, historical development of forensic laboratories, and tools of the criminalists are also discussed. (HM)

  3. A Touch of Relevant Chemistry.

    ERIC Educational Resources Information Center

    Becker, Ernest I.

    1981-01-01

    Suggests using National Institute for Occupational Safety and Health (NIOSH) criteria documents as a source for special topics material in chemistry. Presents a list of selected NIOSH documents, ordering information, and reviews one document on formaldehyde in some detail. (SK)

  4. Organometallic Chemistry. Final Progress Report

    SciTech Connect

    2003-07-14

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

  5. Part 7: Environmental Chemistry, Revised.

    ERIC Educational Resources Information Center

    Douville, Judith A.

    2003-01-01

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

  6. A primer on gadolinium chemistry

    PubMed Central

    Sherry, A. Dean; Caravan, Peter; Lenkinski, Robert E.

    2010-01-01

    Gadolinium is widely known by all practitioners of MRI but few appreciate the basic solution chemistry of this trivalent lanthanide ion. Given the recent linkage between gadolinium contrast agents and nephrogenic systemic fibrosis, some basic chemistry of this ion must be more widely understood. This short primer on gadolinium chemistry is intended to provide the reader the background principles necessary to understand the basics of chelation chemistry, water hydration numbers, and the differences between thermodynamic stability and kinetic stability or inertness. We illustrate the fundamental importance of kinetic dissociation rates in determining gadolinium toxicity in vivo by presenting new data for a novel europium DOTA-tetraamide complex that is relatively unstable thermodynamically yet extraordinarily inert kinetically and also quite non-toxic. This, plus other literature evidence forms the basis of the fundamental axiom that it is the kinetic stability of a gadolinium complex, not its thermodynamic stability, that determines its in vivo toxicity. PMID:19938036

  7. Chemistry for the Visually Impaired.

    ERIC Educational Resources Information Center

    Ratliff, Judy L.

    1997-01-01

    Discusses modifications to general education or introductory chemistry courses that allow visually impaired students to participate productively. Describes a strategy for teaching about elements and density, and the construction of a conductivity tester for visually impaired students. (JRH)

  8. Research in actinide chemistry

    SciTech Connect

    Not Available

    1989-01-01

    Research continued to be focused broadly on the chemistry of the actinide cations in solution. While the direct concern is the actinide elements, their radioactivity limits the techniques which can be applied to their study. A major area of interest continues to be the thermodynamics of interaction of the f-elements with a broad spectrum of inorganic and organic ligands. Solvent extraction (for tracer levels), potentiometric and calorimetric titration and absorption spectrometry have been used to obtain stability constants and the associated enthalpy and entropy changes for complexation. A number of studies were performed to provide a better data base and a better understanding of the more significant species determining the behavior of actinides in natural waters (e.g., hydrolysis and silicate interaction). A second major area has been kinetics. NpO{sub 2}{sup 2+} reduction by hydroxy and carboxylic acids was studied to obtain an understanding of how such functional groups in humic substances may influence actinyl redox. The kinetics of dissociation of UO{sub 2}{sup 2+} and Ln{sup 3+} (La{sup 3+} = lanthanide element cations) from synthetic polyelectrolytes and humics provided significantly increased understanding of actinide complexation by these macromolecules. A third area of activity used laser induced fluorescence to study the hydration state of Eu(III) in a number of systems. Finally, several other studies, not in these major areas, were conducted. These included investigation of NpO{sub 2}{sup +} cation-cation complexes, the extraction of Am(III) by MX (M = Li, Na, NH{sub 4}{sup +}, K{sup +}; X = ClO{sub 4}{sup {minus}}, Cl{sup {minus}}, NO{sub 3}{sup {minus}}, BrO{sub 3}{sup {minus}}) over a concentration range from 0.01 M to saturated and the thermodynamics of synergistic extraction of actinides by crown ethers and {beta}-diketonates. 23 refs., 1 fig.

  9. Chemistry of fast electrons

    PubMed Central

    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

  10. Mars Aqueous Chemistry Experiment (MACE)

    NASA Technical Reports Server (NTRS)

    Benton, Clark C. (Editor)

    1995-01-01

    The concept of an aqueous-based chemical analyzer for Martian surface materials has been demonstrated to be feasible. During the processes of analysis, design, breadboarding, and most importantly, testing, it has become quite apparent that there are many challenges in implementing such a system. Nonetheless, excellent progress has been made and a number of problems which arose have been solved. The ability to conduct this work under a development environment which is separate and which precedes the project-level development has allowed us to find solutions to these implementation realities at low cost. If the instrument had been selected for a mission without this laboratory pre-project work, the costs of implementation would be much higher. In the four areas covered in Sections D, E, F, and G of this Final Report, outstanding progress has been made. There still remains the task of flight-qualifying certain of the components. This is traditionally done under the aegis of a Flight Project, but just as the concept development can be done at much lower cost when kept small and focused, so could the qualification program of critical parts benefit. We recommend, therefore, that NASA consider means of such qualifications and brass-boarding, in advance of final flight development. This is a generic recommendation, but hardware such as the Mars aqueous chemistry experiment (MACE) and other similarly-new concepts are particularly applicable. MACE now has wide versatility, in being able to reliably dispense both liquids and solids as chemical reagents to an entire suite of samples. The hardware and the experiment is much simpler than was developed for the Viking Biology instrument, yet can accomplish all the inorganic chemical measurements that the Viking desing was capable of. In addition, it is much more flexible and versatile to new experiment protocols (and reagents) than the Viking design ever could have been. MACE opens up the opportunity for many different scientific

  11. Mars Aqueous Chemistry Experiment (MACE)

    NASA Astrophysics Data System (ADS)

    Benton, Clark C.

    1995-12-01

    The concept of an aqueous-based chemical analyzer for Martian surface materials has been demonstrated to be feasible. During the processes of analysis, design, breadboarding, and most importantly, testing, it has become quite apparent that there are many challenges in implementing such a system. Nonetheless, excellent progress has been made and a number of problems which arose have been solved. The ability to conduct this work under a development environment which is separate and which precedes the project-level development has allowed us to find solutions to these implementation realities at low cost. If the instrument had been selected for a mission without this laboratory pre-project work, the costs of implementation would be much higher. In the four areas covered in Sections D, E, F, and G of this Final Report, outstanding progress has been made. There still remains the task of flight-qualifying certain of the components. This is traditionally done under the aegis of a Flight Project, but just as the concept development can be done at much lower cost when kept small and focused, so could the qualification program of critical parts benefit. We recommend, therefore, that NASA consider means of such qualifications and brass-boarding, in advance of final flight development. This is a generic recommendation, but hardware such as the Mars aqueous chemistry experiment (MACE) and other similarly-new concepts are particularly applicable. MACE now has wide versatility, in being able to reliably dispense both liquids and solids as chemical reagents to an entire suite of samples. The hardware and the experiment is much simpler than was developed for the Viking Biology instrument, yet can accomplish all the inorganic chemical measurements that the Viking design was capable of. In addition, it is much more flexible and versatile to new experiment protocols (and reagents) than the Viking design ever could have been. MACE opens up the opportunity for many different scientific

  12. Time-dependent interstellar chemistry

    NASA Technical Reports Server (NTRS)

    Glassgold, A. E.

    1985-01-01

    Some current problems in interstellar chemistry are considered in the context of time-dependent calculations. The limitations of steady-state models of interstellar gas-phase chemistry are discussed, and attempts to chemically date interstellar clouds are reviewed. The importance of studying the physical and chemical properties of interstellar dust is emphasized. Finally, the results of a series of studies of collapsing clouds are described.

  13. Physical chemistry and the environment

    SciTech Connect

    Dunning, T.H. Jr.; Garrett, B.C.; Kolb, C.E. Jr.; Shaw, R.W.; Choppin, G.R.; Wagner, A.F.

    1994-08-01

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

  14. Creating a Context for Chemistry

    NASA Astrophysics Data System (ADS)

    Truman Schwartz, A.

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

  15. Click chemistry patents and their impact on drug discovery and chemical biology.

    PubMed

    Xu, Hua; Jones, Lyn H

    2015-01-01

    First introduced by K Barry Sharpless in 2001, the term 'click chemistry' soon became a widely used description of chemical reactions that proceed rapidly, cleanly and in a manner that is often compatible with aqueous solutions. Click chemistry is frequently employed throughout the process of drug discovery, and greatly helps advance research programs in the pharmaceutical industry. It facilitates library synthesis to support medicinal chemistry optimization, helps identify the targets and off-targets of drug candidates, and can facilitate the determination of drug efficacy in clinical trials. In the last decade, a large number of patent applications covering the various types and utilities of click chemistry have been filed. In this review, we provide the first analysis of click chemistry applications. PMID:25853470

  16. Effective Chemistry Communication in Informal Environments

    ERIC Educational Resources Information Center

    National Academies Press, 2016

    2016-01-01

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

  17. The Place of Macromolecules in Freshman Chemistry

    ERIC Educational Resources Information Center

    Wunderlich, Bernhard

    1973-01-01

    Discusses the inclusion of knowledge on macromolecules into a freshman chemistry course which emphasizes topics in organic chemistry, polymer science and biochemistry, atoms, chemical thermodynamics, and inorganic chemistry. Indicates that the program is the only way to keep chemistry education up to date. (CC)

  18. Working Memory and Difficulties in School Chemistry

    ERIC Educational Resources Information Center

    Hussein, Furat; Reid, Norman

    2009-01-01

    The difficulties of learning chemistry are related to the nature of chemistry itself and the methods by which chemistry is customarily taught. Frequently, the way of presenting chemistry does not take into account the psychology of the learner. With senior school pupils (over 1600 were involved) in the Emirates, a series of studies was conducted,…

  19. New Trends in Chemistry Teaching, Volume 2.

    ERIC Educational Resources Information Center

    Cartmell, E.

    This second volume of UNESCO's series on New Trends in Chemistry Teaching presents papers originally published during 1966 and 1967 in leading chemistry-teaching periodicals of the world. The papers have been grouped in sections - structure, energetics and kinetics, acids and bases, organic chemistry, electrochemistry, chemistry and industry,…

  20. 42 CFR 493.839 - Condition: Chemistry.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: Chemistry. 493.839 Section 493.839... These Tests § 493.839 Condition: Chemistry. The specialty of chemistry includes for the purposes of proficiency testing the subspecialties of routine chemistry, endocrinology, and toxicology....