Sample records for beginning catalysis research

  1. Research on Catalysis. (United States)

    Bartholomew, Calvin H.; Hecker, William C.


    The objectives and philosophy of the Catalysis Laboratory at Brigham Young University are discussed. Also discusses recent and current research activities at the laboratory as well as educational opportunities, research facilities, and sources of research support. (JN)

  2. Operando research in heterogeneous catalysis

    CERN Document Server

    Groot, Irene


    This book is devoted to the emerging field of techniques for visualizing atomic-scale properties of active catalysts under actual working conditions, i.e. high gas pressures and high temperatures. It explains how to understand these observations in terms of the surface structures and dynamics and their detailed interplay with the gas phase. This provides an important new link between fundamental surface physics and chemistry, and applied catalysis. The book explains the motivation and the necessity of operando studies, and positions these with respect to the more traditional low-pressure investigations on the one hand and the reality of industrial catalysis on the other. The last decade has witnessed a rapid development of new experimental and theoretical tools for operando studies of heterogeneous catalysis. The book has a strong emphasis on the new techniques and illustrates how the challenges introduced by the harsh, operando conditions are faced for each of these new tools. Therefore, one can also read th...

  3. Advanced Resources for Catalysis Science; Recommendations for a National Catalysis Research Institute

    Energy Technology Data Exchange (ETDEWEB)

    Peden, Charles HF.; Ray, Douglas


    Catalysis is one of the most valuable contributors to our economy and historically an area where the United States has enjoyed, but is now losing, international leadership. While other countries are stepping up their work in this area, support for advanced catalysis research and development in the U.S. has diminished. Yet, more than ever, innovative and improved catalyst technologies are imperative for new energy production processes to ease our dependence on imported resources, for new energy-efficient and environmentally benign chemical production processes, and for new emission reduction technologies to minimize the environmental impact of an active and growing economy. Addressing growing concerns about the future direction of U.S. catalysis science, experts from the catalysis community met at a workshop to determine and recommend advanced resources needed to address the grand challenges for catalysis research and development. The workshop's primary conclusion: To recapture our position as the leader in catalysis innovation and practice, and promote crucial breakthroughs, the U.S. must establish one or more well-funded and well-equipped National Catalysis Research Institutes competitively selected, centered in the national laboratories and, by charter, networked to other national laboratories, universities, and industry. The Institute(s) will be the center of a national collaboratory that gives catalysis researchers access to the most advanced techniques available in the scientific enterprise. The importance of catalysis to our energy, economic, and environmental security cannot be overemphasized. Catalysis is a vital part of our core industrial infrastructure, as it is integral to chemical processing and petroleum refining, and is critical to proposed advances needed to secure a sustainable energy future. Advances in catalysis could reduce our need for foreign oil by making better use of domestic carbon resources, for example, allowing cost-effective and

  4. DOE Laboratory Catalysis Research Symposium - Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, T.


    The conference consisted of two sessions with the following subtopics: (1) Heterogeneous Session: Novel Catalytic Materials; Photocatalysis; Novel Processing Conditions; Metals and Sulfides; Nuclear Magnetic Resonance; Metal Oxides and Partial Oxidation; Electrocatalysis; and Automotive Catalysis. (2) Homogeneous Catalysis: H-Transfer and Alkane Functionalization; Biocatalysis; Oxidation and Photocatalysis; and Novel Medical, Methods, and Catalyzed Reactions.

  5. Beginnings and advances in heavy ion research

    International Nuclear Information System (INIS)

    Brix, P.


    The very important field of heavy ion research is briefly reviewed from the beginnings up to the present time. The article was intended to be a scientific lecture for the general public read on the occasion of the 70th birthday of Prof. Schmelzer. (KBE)

  6. Dedicated Beamline Facilities for Catalytic Research. Synchrotron Catalysis Consortium (SCC)

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jingguang [Columbia Univ., New York, NY; Frenkel, Anatoly [Yeshiva Univ., New York, NY (United States); Rodriguez, Jose [Brookhaven National Lab. (BNL), Upton, NY (United States); Adzic, Radoslav [Brookhaven National Lab. (BNL), Upton, NY (United States); Bare, Simon R. [UOP LLC, Des Plaines, IL (United States); Hulbert, Steve L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Karim, Ayman [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mullins, David R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Overbury, Steve [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    Synchrotron spectroscopies offer unique advantages over conventional techniques, including higher detection sensitivity and molecular specificity, faster detection rate, and more in-depth information regarding the structural, electronic and catalytic properties under in-situ reaction conditions. Despite these advantages, synchrotron techniques are often underutilized or unexplored by the catalysis community due to various perceived and real barriers, which will be addressed in the current proposal. Since its establishment in 2005, the Synchrotron Catalysis Consortium (SCC) has coordinated significant efforts to promote the utilization of cutting-edge catalytic research under in-situ conditions. The purpose of the current renewal proposal is aimed to provide assistance, and to develop new sciences/techniques, for the catalysis community through the following concerted efforts: Coordinating the implementation of a suite of beamlines for catalysis studies at the new NSLS-II synchrotron source; Providing assistance and coordination for catalysis users at an SSRL catalysis beamline during the initial period of NSLS to NSLS II transition; Designing in-situ reactors for a variety of catalytic and electrocatalytic studies; Assisting experimental set-up and data analysis by a dedicated research scientist; Offering training courses and help sessions by the PIs and co-PIs.

  7. 2008 Gordon Research Conference on Catalysis [Conference summary report

    Energy Technology Data Exchange (ETDEWEB)

    Soled, Stuart L.; Gray, Nancy Ryan


    The GRC on Catalysis is one of the most prestigious catalysis conferences as it brings together leading researchers from around the world to discuss their latest, most exciting work in catalysis. The 2008 conference will continue this tradition. The conference will cover a variety of themes including new catalytic materials, theoretical and experimental approaches to improve understanding of kinetics and transport phenomena, and state of the art nanoscale characterization probes to monitor active sites. The conference promotes interactions among established researchers and young scientists. It provides a venue for students to meet, talk to and learn from some of the world leading researchers in the area. It also gives them a platform for displaying their own work during the poster sessions. The informal nature of the meeting, excellent quality of the presentations and posters, and ability to meet many outstanding colleagues makes this an excellent conference.

  8. Seventh BES (Basic Energy Sciences) catalysis and surface chemistry research conference

    Energy Technology Data Exchange (ETDEWEB)


    Research programs on catalysis and surface chemistry are presented. A total of fifty-seven topics are included. Areas of research include heterogeneous catalysis; catalysis in hydrogenation, desulfurization, gasification, and redox reactions; studies of surface properties and surface active sites; catalyst supports; chemical activation, deactivation; selectivity, chemical preparation; molecular structure studies; sorption and dissociation. Individual projects are processed separately for the data bases. (CBS)

  9. Seventh BES [Basic Energy Sciences] catalysis and surface chemistry research conference

    International Nuclear Information System (INIS)


    Research programs on catalysis and surface chemistry are presented. A total of fifty-seven topics are included. Areas of research include heterogeneous catalysis; catalysis in hydrogenation, desulfurization, gasification, and redox reactions; studies of surface properties and surface active sites; catalyst supports; chemical activation, deactivation; selectivity, chemical preparation; molecular structure studies; sorption and dissociation. Individual projects are processed separately for the data bases

  10. Coal-related research, organic chemistry, and catalysis

    International Nuclear Information System (INIS)



    Coal chemistry research topics included: H exchange at 400 0 C, breaking C-C bonds in coal, molecular weight estimation using small-angle neutron scattering, 13 C NMR spectra of coals, and tunneling during H/D isotope effects. Studies of coal conversion chemistry included thermolysis of bibenzyl and 1-naphthol, heating of coals in phenol, advanced indirect liquefaction based on Koelbel slurry Fischer-Tropsch reactor, and plasma oxidation of coal minerals. Reactions of PAHs in molten SbCl 3 , a hydrocracking catalyst, were studied. Finally, heterogeneous catalysis (desulfurization etc.) was studied using Cu, Au, and Ni surfaces. 7 figures, 6 tables

  11. Mentoring Beginning Teachers in Primary Schools: Research Review (United States)

    Spooner-Lane, Rebecca


    While mentoring programmes have proven to be successful in reducing attrition and improving teaching ability in beginning teachers, there remains a lack of research delineating the key components of effective mentoring programmes in primary education. This integrative research review examines empirical studies conducted since 2000 on the nature…

  12. Challenges Confronting Beginning Researchers in Conducting Literature Reviews (United States)

    Chen, Der-Thanq; Wang, Yu-Mei; Lee, Wei Ching


    Conducting literature review is a complicated, sometimes confusing and laborious process that beginning educational researchers, especially graduate students, often find challenging. However, in the past these challenges were hardly considered, but in more recent times they have been increasingly considered by various faculties and graduate…


    Energy Technology Data Exchange (ETDEWEB)

    Abhaya Datye


    Catalysis is a key technology for improving the quality of life while simultaneously reducing the adverse impact of human activities on the environment. The discovery of new catalytic processes and the improvement of existing ones are also critically important for securing the nation's energy supply. The GRC on Catalysis is considered one the most prestigious conference for catalysis research, bringing together leading researchers from both academia, industry and national labs to discuss the latest, most exciting research in catalysis and the future directions for the field. The 2010 GRC on Catalysis will follow time-honored traditions and feature invited talks from the world's leading experts in the fundamentals and applications of catalytic science and technology. We plan to have increased participation from industry. The extended discussions in the company of outstanding thinkers will stimulate and foster new science. The conference will include talks in the following areas: Alternative feedstocks for chemicals and fuels, Imaging and spectroscopy, Design of novel catalysts, Catalyst preparation fundamentals, Molecular insights through theory, Surface Science, Catalyst stability and dynamics. In 2010, the Catalysis conference will move to a larger conference room with a new poster session area that will allow 40 posters per session. The dorm rooms provide single and double accommodations, free WiFi and the registration fee includes all meals and the famous lobster dinner on Thursday night. Afternoons are open to enjoy the New England ambiance with opportunities for hiking, sailing, golf and tennis to create an outstanding conference that will help you network with colleagues, and make long lasting connections.

  14. Consideration of the Aluminum Distribution in Zeolites in Theoretical and Experimental Catalysis Research

    Energy Technology Data Exchange (ETDEWEB)

    Knott, Brandon C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Robichaud, David J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nimlos, Mark R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kim, Seon Ah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nimlos, Claire T. [Purdue University; Gounder, Rajamani [Purdue University


    Research efforts in zeolite catalysis have become increasingly cognizant of the diversity in structure and function resulting from the distribution of framework aluminum atoms, through emerging reports of catalytic phenomena that fall outside those recognizable as the shape-selective ones emblematic of its earlier history. Molecular-level descriptions of how active-site distributions affect catalysis are an aspirational goal articulated frequently in experimental and theoretical research, yet they are limited by imprecise knowledge of the structure and behavior of the zeolite materials under interrogation. In experimental research, higher precision can result from more reliable control of structure during synthesis and from more robust and quantitative structural and kinetic characterization probes. In theoretical research, construction of models with specific aluminum locations and distributions seldom capture the heterogeneity inherent to the materials studied by experiment. In this Perspective, we discuss research findings that appropriately frame the challenges in developing more predictive synthesis-structure-function relations for zeolites, highlighting studies on ZSM-5 zeolites that are among the most structurally complex molecular sieve frameworks and the most widely studied because of their versatility in commercial applications. We discuss research directions to address these challenges and forge stronger connections between zeolite structure, composition, and active sites to catalytic function. Such connections promise to aid in bridging the findings of theoretical and experimental catalysis research, and transforming zeolite active site design from an empirical endeavor into a more predictable science founded on validated models.

  15. Advances in catalysis

    CERN Document Server

    Gates, Bruce C


    Advances in Catalysis fills the gap between the journal papers and the textbooks across the diverse areas of catalysis research. For more than 60 years Advances in Catalysis has been dedicated to recording progress in the field of catalysis and providing the scientific community with comprehensive and authoritative reviews. This series in invaluable to chemical engineers, physical chemists, biochemists, researchers and industrial chemists working in the fields of catalysis and materials chemistry. * In-depth, critical, state-of-the-art reviews * Comprehensive, covers of all as

  16. Teaching Beginning College Students with Adapted Published Research Reports (United States)

    Klemm, William R.


    This study used peer-reviewed published research reports to teach a seminar on learning and memory to first-semester college students. Complete reports (not summaries, reviews, or news reports) were re-written by this author to be more "student friendly" to college freshmen. These adapted published research reports (APRRs) retained…

  17. Beginning Counselor Educators' Experiences Developing a Research Agenda (United States)

    Wilde, Brandon J.


    To date, counselor education literature is narrow in the accounts of counselor educators' experiences as active scholars (Hill, 2004). Consequently, there is little research accounting for the experience of developing a research agenda for counselor educators during their initial faculty appointment. Hermeneutic, phenomenological methodology was…

  18. Supramolecular catalysis: Refocusing catalysis

    NARCIS (Netherlands)

    van Leeuwen, P.W.N.M.; Freixa, Z.; van Leeuwen, P.W.N.M.


    This chapter contains sections titled: * Introduction: A Brief Personal History * Secondary Phosphines or Phosphites as Supramolecular Ligands * Host-Guest Catalysis * Ionic Interactions as a Means to Form Heterobidentate Assembly Ligands * Ditopic Ligands for the Construction of Bidentate Phosphine

  19. Cold Neutron Research Facility begins operating at NIST

    International Nuclear Information System (INIS)

    Zeman, E.J.


    Steady-state neutron beams are generally produced by fission in a nuclear reactor, whereas pulsed beams come from spallation neutron sources. Beams from a reactor have a distribution of wavelengths that is roughly Maxwellian, with a peak wavelength that depends on the temperature of the moderator that surrounds the fuel. Cold neutrons can be selected from the low-energy tail of the distribution, but the flux drops as 1/λ 4 . However, by shifting the whole spectrum to longer wavelengths one can dramatically increase the cold neutron flux. This is achieved by replacing part of the core moderator with a cold moderator, or 'cold source,' such as liquid deuterium (at about 30 K) or D 2 O ice (at about 40 K). Neutrons lose energy to the moderator through collisions, producing a shifted spectrum from which one can select lower-energy neutrons with a roughly ten-fold improvement in the flux. Neutrons exhibit optical behavior such as refraction and total reflection. Thus one can use neutron guides - analogous to optical fibers - to conduct intense beams of neutrons from the reactor into a large experimental hall, dubbed a 'guide hall,' where background radiation is low. The Cold Neutron Research Facility was finally funded in 1987 and opened its doors this past June. CNRF is located at the 20-MW NIST research reactor, which began continuous operation in 1969. With some foresight, the designers of the original reactor allowed space for the addition of a cryogenic moderator, which is only now being exploited. NIST will develop 10 experimental stations for use by the research science community. Additional help in financing the facility comes from participating research teams made up of groups from industry, academe and government

  20. NATO Advanced Research Workshop on Frontiers in Polymerization Catalysis and Polymer Synthesis

    CERN Document Server

    Guyot, A


    Due to their specific properties, polymers with well-defined structures have been receiving increasing attention over the last several years. Owing to the wide variability of their properties, these specialty polymers have been used in various areas from biomedical engineering to electronics or energy applications. The synthesis of such polymers necessi­ tates the use of new methods of polymerization which derived from an insight into the mechanism of polymerization reactions. A NATO Advanced Research Workshop on "Frontiers in Polymerization Catalysis and Polymer Synthesis" was held in BANDOl (FRANCE) in February 1987. Its aim was to assess the new polymerization methods, as well as the latest advances in the mechanisms of conventional polymerization reactions together with their applications to the synthesis of new macromolecular structures. The financial support from the NATO Scientific Affairs Division which covered the "lecturers' accomodation and travel expenses as well as the organization charges of th...

  1. Catalysis studies

    International Nuclear Information System (INIS)

    Taylor, T.N.; Ellis, W.P.


    The New Research Initiatives Program (NRIP) project on catalysis in Los Alamos Scientific Laboratory (LASL) Group CMB-8 has made significant progress towards performing the first basic in situ experimental studies of heterogeneous catalysis on solid compound surfaces in a LEED-Auger system. To further understand the surface crystallography of a possible catalyst compound, LEED-Auger measurements were made on UO 2 (approximately 100) vicinal surfaces. These (approximately 100) vicinal surfaces were shown to decompose irreversibly into lower index facets, including prominent (100) facets, at temperatures below those needed for creation of lowest index faceting on (approximately 111) vicinal surfaces. LEED examination of fully faceted surfaces from both types of UO 2 vicinal cuts did not show evidence of cyclopropane or propene chemisorption. The existing LEED-Auger system was modified to allow catalytic reactions at approximately less than 10 -3 torr. A sample holder, specifically designed for catalysis measurements in the modified system, was tested while examining single crystals of CoO and Cr 2 O 3 . Extensive LEED-Auger measurements were made on CoO in vacuo and in the presence of light hydrocarbons and alcohols plus H 2 O, NO, and NH 3 . No chemisorptive behavior was observed except with H 2 O in the presence of the electron beam. Although only examined briefly, the Cr 2 O 3 was remarkable for the sharp LEED features obtained prior to any surface treatment in the vacuum system

  2. Catalysis seen in action

    NARCIS (Netherlands)

    Tromp, M.


    Synchrotron radiation techniques are widely applied in materials research and heterogeneous catalysis. In homogeneous catalysis, its use so far is rather limited despite its high potential. Here, insights in the strengths and limitations of X-ray spectroscopy technique in the field of homogeneous

  3. Heterogeneous Catalysis. (United States)

    Vannice, M. A.


    Described is a graduate course in catalysis offered at Penn State University. A detailed course outline with 30 lecture topics is presented. A list of 42 references on catalysis used in place of a textbook is provided. (BT)

  4. Tacit Information Literacies in Beginning College Students: Research Pedagogy in Geography (United States)

    Bauch, Nicholas; Sheldon, Christina


    Whereas instruction on how to conduct original research can build on beginning college students' tacit information literacies, the explicit articulation of existing processes for information gathering is rarely elicited by instructors prior to students' submission of a final research paper. In this essay, authors Nicholas Bauch and Christina…

  5. Golf science research at the beginning of the twenty-first century. (United States)

    Farrally, M R; Cochran, A J; Crews, D J; Hurdzan, M J; Price, R J; Snow, J T; Thomas, P R


    At the beginning of the twenty-first century, there are 30,000 golf courses and 55 million people who play golf worldwide. In the USA alone, the value of golf club memberships sold in the 1990s was US dollar 3.2 billion. Underpinning this significant human activity is a wide variety of people researching and applying science to sustain and develop the game. The 11 golf science disciplines recognized by the World Scientific Congress of Golf have reported 311 papers at four world congresses since 1990. Additionally, scientific papers have been published in discipline-specific peer-reviewed journals, research has been sponsored by the two governing bodies of golf, the Royal and Ancient Golf Club of St. Andrews and the United States Golf Association, and confidential research is undertaken by commercial companies, especially equipment manufacturers. This paper reviews much of this human endeavour and points the way forward for future research into golf.

  6. Doing Case Study Research: A Practical Guide for Beginning Researchers. Third Edition (United States)

    Hancock, Dawson R.; Algozzine, Bob


    Reflecting recent knowledge and developments in the field, this very practical, easy-to-use guide emphasizes learning how to do case study research--from the first step of deciding whether a case study is the way to go to the last step of verifying and confirming findings before disseminating them. The authors show students how to determine an…

  7. The CAT-ACT Beamline at ANKA: A new high energy X-ray spectroscopy facility for CATalysis and ACTinide research (United States)

    Zimina, A.; Dardenne, K.; Denecke, M. A.; Grunwaldt, J. D.; Huttel, E.; Lichtenberg, H.; Mangold, S.; Pruessmann, T.; Rothe, J.; Steininger, R.; Vitova, T.


    A new hard X-ray beamline for CATalysis and ACTinide research has been built at the synchrotron radiation facility ANKA. The beamline design is dedicated to X-ray spectroscopy, including ‘flux hungry’ photon-in/photon-out and correlative techniques with a special infrastructure for radionuclide and catalysis research. The CAT-ACT beamline will help serve the growing need for high flux/hard X-ray spectroscopy in these communities. The design, the first spectra and the current status of this project are reported.

  8. The Era of International Space Station Utilization Begins: Research Strategy, International Collaboration, and Realized Potential (United States)

    Thumm, Tracy; Robinson, Julie A.; Ruttley, Tara; Johnson-Green, Perry; Karabadzhak, George; Nakamura, Tai; Sorokin, Igor V.; Zell, Martin; Jean, Sabbagh


    With the assembly of the International Space Station (ISS) nearing completion and the support of a full-time crew of six, a new era of utilization for research is beginning. For more than 15 years, the ISS international partnership has weathered financial, technical and political challenges proving that nations can work together to complete assembly of the largest space vehicle in history. And while the ISS partners can be proud of having completed one of the most ambitious engineering projects ever conceived, the challenge of successfully using the platform remains. During the ISS assembly phase, the potential benefits of space-based research and development were demonstrated; including the advancement of scientific knowledge based on experiments conducted in space, development and testing of new technologies, and derivation of Earth applications from new understanding. The configurability and human-tended capabilities of the ISS provide a unique platform. The international utilization strategy is based on research ranging from physical sciences, biology, medicine, psychology, to Earth observation, human exploration preparation and technology demonstration. The ability to complete follow-on investigations in a period of months allows researchers to make rapid advances based on new knowledge gained from ISS activities. During the utilization phase, the ISS partners are working together to track the objectives, accomplishments, and the applications of the new knowledge gained. This presentation will summarize the consolidated international results of these tracking activities and approaches. Areas of current research on ISS with strong international cooperation will be highlighted including cardiovascular studies, cell and plant biology studies, radiation, physics of matter, and advanced alloys. Scientific knowledge and new technologies derived from research on the ISS will be realized through improving quality of life on Earth and future spaceflight endeavours

  9. Catalysis seen in action. (United States)

    Tromp, Moniek


    Synchrotron radiation techniques are widely applied in materials research and heterogeneous catalysis. In homogeneous catalysis, its use so far is rather limited despite its high potential. Here, insights in the strengths and limitations of X-ray spectroscopy technique in the field of homogeneous catalysis are given, including new technique developments. A relevant homogeneous catalyst, used in the industrially important selective oligomerization of ethene, is taken as a worked-out example. Emphasis is placed on time-resolved operando X-ray absorption spectroscopy with outlooks to novel high energy resolution and emission techniques. All experiments described have been or can be done at the Diamond Light Source Ltd (Didcot, UK). © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  10. Preface: Catalysis Today

    DEFF Research Database (Denmark)

    Li, Yongdan


    This special issue of Catalysis Today with the theme “Sustain-able Energy” results from a great success of the session “Catalytic Technologies Accelerating the Establishment of Sustainable and Clean Energy”, one of the two sessions of the 1st International Symposium on Catalytic Science and Techn......This special issue of Catalysis Today with the theme “Sustain-able Energy” results from a great success of the session “Catalytic Technologies Accelerating the Establishment of Sustainable and Clean Energy”, one of the two sessions of the 1st International Symposium on Catalytic Science...... and Technology in Sustainable Energy and Environment, held in Tianjin, China during October8–10, 2014. This biennial symposium offers an international forum for discussing and sharing the cutting-edge researches and the most recent breakthroughs in energy and environmental technologies based on catalysis...

  11. Enantioconvergent catalysis

    Directory of Open Access Journals (Sweden)

    Justin T. Mohr


    Full Text Available An enantioconvergent catalytic process has the potential to convert a racemic starting material to a single highly enantioenriched product with a maximum yield of 100%. Three mechanistically distinct approaches to effecting enantioconvergent catalysis are identified, and recent examples of each are highlighted. These processes are compared to related, non-enantioconvergent methods.

  12. Catalysis in VOC Abatement

    Czech Academy of Sciences Publication Activity Database

    Ojala, S.; Pitkäaho, S.; Laitinen, T.; Koivikko, N.N.; Brahmi, R.; Gaálová, Jana; Matějová, Lenka; Kucherov, A.; Päivärinta, S.; Hirschmann, Ch.


    Roč. 54, 16-18 (2011), s. 1224-1256 ISSN 1022-5528. [Nordic Symposium on Catalysis /14./. Marienlyst, Helsingør, 29.08.2010-31.08.2010] Institutional research plan: CEZ:AV0Z40720504 Keywords : voc emissions * voc regulation * effects of VOC's Subject RIV: CC - Organic Chemistry Impact factor: 2.624, year: 2011

  13. Catalysis and biocatalysis program (United States)

    Ingham, J. D.


    This final report presents a summary of research activities and accomplishments for the Catalysis and Biocatalysis Program, which was renamed the Biological and Chemical Technologies Research (BCTR) Program, currently of the Advanced Industrial Concepts Division (AICD), Office of Industrial Technologies of the Department of Energy (DOE). The Program was formerly under the Division of Energy Conversion and Utilization Technologies (ECUT) until the DOE reorganization in April, 1990. The goals of the BCTR Program are consistent with the initial ECUT goals, but represent an increased effort toward advances in chemical and biological technology transfer. In addition, the transition reflects a need for the BCTR Program to assume a greater R&D role in chemical catalysis as well as a need to position itself for a more encompassing involvement in a broader range of biological and chemical technology research. The mission of the AICD is to create a balanced Program of high risk, long-term, directed interdisciplinary research and development that will improve energy efficiency and enhance fuel flexibility in the industrial sector. Under AICD, the DOE Catalysis and Biocatalysis Program sponsors research and development in furthering industrial biotechnology applications and promotes the integrated participation of universities, industrial companies, and government research laboratories.

  14. Editorial: Nanoscience makes catalysis greener

    KAUST Repository

    Polshettiwar, Vivek


    Green chemistry by nanocatalysis: Catalysis is a strategic field of science because it involves new ways of meeting energy and sustainability challenges. The concept of green chemistry, which makes the science of catalysis even more creative, has become an integral part of sustainability. This special issue is at the interface of green chemistry and nanocatalysis, and features excellent background articles as well as the latest research results. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Beginning topology

    CERN Document Server

    Goodman, Sue E


    Beginning Topology is designed to give undergraduate students a broad notion of the scope of topology in areas of point-set, geometric, combinatorial, differential, and algebraic topology, including an introduction to knot theory. A primary goal is to expose students to some recent research and to get them actively involved in learning. Exercises and open-ended projects are placed throughout the text, making it adaptable to seminar-style classes. The book starts with a chapter introducing the basic concepts of point-set topology, with examples chosen to captivate students' imaginations while i

  16. Applications of Electrospray Ionization Mass Spectrometry in Mechanistic Studies and Catalysis Research

    Czech Academy of Sciences Publication Activity Database

    Schröder, Detlef


    Roč. 45, č. 9 (2012), s. 1521-1532 ISSN 0001-4842 Grant - others:European Research Council(XE) AdG HORIZOMS Institutional support: RVO:61388963 Keywords : cross-coupling reactions * Baylis–Hillman reaction * molecular-dynamics simulations * solution-phase mechanism * gas-phase * infrared-spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 20.833, year: 2012

  17. International Assessment of Research and Development in Catalysis by Nanostructured Materials (United States)


    forming indene derivatives from a titanocene species, and an asymmetric kinetic resolution of a planar chiral ferrocene by Mo-catalyzed metathesis...multifunction reactor. He is using hydrogen TPR, in situ FTIR , GC, mass spectroscopy, Raman, XRD, and TEM for characterization of catalyst structure and...research, e.g., solid-state NMR; 5 noncontact AFM, SEM, and STM units; photon emission 242 Appendix C. Site Reports—Asia microscope; 3 FTIRs ; 1

  18. Molecular ingredients of heterogeneous catalysis

    International Nuclear Information System (INIS)

    Somorjai, G.A.


    The purpose of this paper is to present a review and status report to those in theoretical chemistry of the rapidly developing surface science of heterogeneous catalysis. The art of catalysis is developing into science. This profound change provides one with opportunities not only to understand the molecular ingredients of important catalytic systems but also to develop new and improved catalyst. The participation of theorists to find answers to important questions is sorely needed for the sound development of the field. It is the authors hope that some of the outstanding problems of heterogeneous catalysis that are identified in this paper will be investigated. For this purpose the paper is divided into several sections. The brief Introduction to the methodology and recent results of the surface science of heterogeneous catalysis is followed by a review of the concepts of heterogeneous catalysis. Then, the experimental results that identified the three molecular ingredients of catalysis, structure, carbonaceous deposit and the oxidation state of surface atoms are described. Each section is closed with a summary and a list of problems that require theoretical and experimental scrutiny. Finally attempts to build new catalyst systems and the theoretical and experimental problems that appeared in the course of this research are described

  19. Molecular ingredients of heterogeneous catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.


    The purpose of this paper is to present a review and status report to those in theoretical chemistry of the rapidly developing surface science of heterogeneous catalysis. The art of catalysis is developing into science. This profound change provides one with opportunities not only to understand the molecular ingredients of important catalytic systems but also to develop new and improved catalyst. The participation of theorists to find answers to important questions is sorely needed for the sound development of the field. It is the authors hope that some of the outstanding problems of heterogeneous catalysis that are identified in this paper will be investigated. For this purpose the paper is divided into several sections. The brief Introduction to the methodology and recent results of the surface science of heterogeneous catalysis is followed by a review of the concepts of heterogeneous catalysis. Then, the experimental results that identified the three molecular ingredients of catalysis, structure, carbonaceous deposit and the oxidation state of surface atoms are described. Each section is closed with a summary and a list of problems that require theoretical and experimental scrutiny. Finally attempts to build new catalyst systems and the theoretical and experimental problems that appeared in the course of this research are described.

  20. pClone: Synthetic Biology Tool Makes Promoter Research Accessible to Beginning Biology Students (United States)

    Campbell, A. Malcolm; Eckdahl, Todd; Cronk, Brian; Andresen, Corinne; Frederick, Paul; Huckuntod, Samantha; Shinneman, Claire; Wacker, Annie; Yuan, Jason


    The "Vision and Change" report recommended genuine research experiences for undergraduate biology students. Authentic research improves science education, increases the number of scientifically literate citizens, and encourages students to pursue research. Synthetic biology is well suited for undergraduate research and is a growing area…

  1. Using administrative data for your research project: 10 considerations before you begin. (United States)

    Brouwer, Emily S; Policastri, Anne; Moga, Daniela C


    With increasing pressure to conduct research during residency training, and given the availability of administrative claims data, pharmacy residents will likely consider using large administrative databases for their research project. With competing time commitments and the short duration of residencies, residents and their preceptors must consider the 10 factors outlined above in order to produce a thoughtful, clinically relevant research project. While this discussion focused on the completion of a residency research project, these topics are also relevant to a broader pharmacy audience. Colleges of pharmacy are increasingly requiring research projects as part of their curriculum, and pharmacy students and practitioners often consider obtaining additional degrees requiring a research component. Both students and practitioners can use the guidance provided herein when planning research projects and investigations to aid in the successful completion of research using administrative claims data.

  2. EMSL and Institute for Integrated Catalysis (IIC) Catalysis Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Charles T.; Datye, Abhaya K.; Henkelman, Graeme A.; Lobo, Raul F.; Schneider, William F.; Spicer, Leonard D.; Tysoe, Wilfred T.; Vohs, John M.; Baer, Donald R.; Hoyt, David W.; Thevuthasan, Suntharampillai; Mueller, Karl T.; Wang, Chong M.; Washton, Nancy M.; Lyubinetsky, Igor; Teller, Raymond G.; Andersen, Amity; Govind, Niranjan; Kowalski, Karol; Kabius, Bernd C.; Wang, Hongfei; Campbell, Allison A.; Shelton, William A.; Bylaska, Eric J.; Peden, Charles HF; Wang, Yong; King, David L.; Henderson, Michael A.; Rousseau, Roger J.; Szanyi, Janos; Dohnalek, Zdenek; Mei, Donghai; Garrett, Bruce C.; Ray, Douglas; Futrell, Jean H.; Laskin, Julia; DuBois, Daniel L.; Kuprat, Laura R.; Plata, Charity


    Within the context of significantly accelerating scientific progress in research areas that address important societal problems, a workshop was held in November 2010 at EMSL to identify specific and topically important areas of research and capability needs in catalysis-related science.

  3. Authentic Science Research Opportunities: How Do Undergraduate Students Begin Integration into a Science Community of Practice? (United States)

    Gardner, Grant E.; Forrester, Jennifer H.; Jeffrey, Penny Shumaker; Ferzli, Miriam; Shea, Damian


    The goal of the study described was to understand the process and degree to which an undergraduate science research program for rising college freshmen achieved its stated objectives to integrate participants into a community of practice and to develop students' research identities.

  4. Emergence of Qualitative Research in Colombian Psychology: A Beginning that Still Does not End


    Jorge Larreamendy-Joerns; Juanita Henao; Alexandra Arango


    This article deals with the processes of emergence and evolution of qualitative research in psychology in Colombia. Two major arguments are advanced. First, these processes can only be fully understood in the light of the history of psychology in Colombia, and, at the same time, within the context of emergence and consolidation of the social sciences in Colombia. Second, the evolution of qualitative research in North American psychology coincides in some aspects with its corresponding path in...

  5. Catalysis of Photochemical Reactions. (United States)

    Albini, A.


    Offers a classification system of catalytic effects in photochemical reactions, contrasting characteristic properties of photochemical and thermal reactions. Discusses catalysis and sensitization, examples of catalyzed reactions of excepted states, complexing ground state substrates, and catalysis of primary photoproducts. (JM)

  6. pClone: Synthetic Biology Tool Makes Promoter Research Accessible to Beginning Biology Students (United States)

    Eckdahl, Todd; Cronk, Brian; Andresen, Corinne; Frederick, Paul; Huckuntod, Samantha; Shinneman, Claire; Wacker, Annie; Yuan, Jason


    The Vision and Change report recommended genuine research experiences for undergraduate biology students. Authentic research improves science education, increases the number of scientifically literate citizens, and encourages students to pursue research. Synthetic biology is well suited for undergraduate research and is a growing area of science. We developed a laboratory module called pClone that empowers students to use advances in molecular cloning methods to discover new promoters for use by synthetic biologists. Our educational goals are consistent with Vision and Change and emphasize core concepts and competencies. pClone is a family of three plasmids that students use to clone a new transcriptional promoter or mutate a canonical promoter and measure promoter activity in Escherichia coli. We also developed the Registry of Functional Promoters, an open-access database of student promoter research results. Using pre- and posttests, we measured significant learning gains among students using pClone in introductory biology and genetics classes. Student posttest scores were significantly better than scores of students who did not use pClone. pClone is an easy and affordable mechanism for large-enrollment labs to meet the high standards of Vision and Change. PMID:26086659

  7. ‘Spiritalismus vincit Mundum’ Dutch spiritualism and the beginning of psychical research

    Directory of Open Access Journals (Sweden)

    Ingrid Kloosterman


    Full Text Available The science of psychical research and parapsychology stemmed, among other things, from wonder about the phenomena of spiritualism: manifestations of the deceased through mediums in séances. In the Netherlands, academic psychical research emerged in 1919, when the Studievereeniging voor Psychical Research (SPR was founded. In this paper, it is argued that a revival of the popularity of spiritualism during the war contributed to the emergence of the Dutch SPR shortly after the First World War had ended. Mass bereavement does not suffice as an explanation for the growth of the spiritualistic movement in the neutral Netherlands in the war years. It is demonstrated that in the writings of spiritualists about the First World War persistent fin-de-siècle themes can be distinguished. Before and during the First World War Dutch spiritualism was dominated by ‘ideologically’ inclined spiritualists and their more ‘critical-scientific’ counterparts were a minority. This had hindered the development of Dutch psychical research. After the war spiritualists shared their hopeful and optimistic perspective of the human soul with scholars leaning towards psychoanalytical and psychomonist ideas. This eventually led to a joint foundation of the Dutch SPR. This alignment between ideological and critical-scientific spiritualists would not last; opinions on how to handle the research subjects (i.e. mediums remained too distinct.

  8. In the Beginning Was the Other: Lacanian Psychoanalysis and Its Implications for Educational Research Method (United States)

    Hyldgaard, Kirsten


    In much of educational philosophy and sciences the fundamental concepts are the subject conceived of as conscious and constituting and the learning process conceived of as a matter of cognition. This article asks what the effect would be on educational research method and educational theory in general if the fundamental concept were the subject in…

  9. The neurosciences research program at MIT and the beginning of the modern field of neuroscience. (United States)

    Adelman, George


    The interdisciplinary field, "neuroscience," began at MIT in 1962 with the founding of the Neurosciences Research Program (NRP) by Francis O. Schmitt and a group of US and international scientists - physical, biological, medical, and behavioral - interested in understanding the brain basis of behavior and mind. They organized and held specialist meetings of basic topics in neuroscience, and the journal and book publications over the next 20 years, based on these meetings, helped establish the new field.

  10. Controllable Catalysis with Nanoparticles: Bimetallic Alloy Systems and Surface Adsorbates

    KAUST Repository

    Chen, Tianyou


    Transition metal nanoparticles are privileged materials in catalysis due to their high specific surface areas and abundance of active catalytic sites. While many of these catalysts are quite useful, we are only beginning to understand the underlying catalytic mechanisms. Opening the “black box” of nanoparticle catalysis is essential to achieve the ultimate goal of catalysis by design. In this Perspective we highlight recent work addressing the topic of controlled catalysis with bimetallic alloy and “designer” adsorbate-stabilized metal nanoparticles.

  11. Environmental surveillance and research at the Nevada Test Site: The beginning and the rationale

    International Nuclear Information System (INIS)

    Elle, D.R.; Church, B.W.; Bingham, F.E.


    Concurrently with the first nuclear-weapons tests at the Nevada Test Site (NTS) in 1951, an environmental surveillance and monitoring program was established offsite. Initial emphasis was on tracking fallout clouds and measuring external radiation exposure rates. An environmental research program was also initiated. Establishment of comprehensive programs has facilitated the ability to address issues such as the inventory and distribution of radionuclides in surface soils, reconstruction of offsite population doses, and recognition of areas requiring additional information. We have learned that a successful environmental monitoring program must be flexible and responsive to change; must address public as well as technical and regulatory concerns; and results must be continuously interpreted to ensure that all pathways are considered and the programs are proactive in their approach

  12. Precarious beginnings: Gendered risk discourses in psychiatric research literature about postpartum depression. (United States)

    Godderis, Rebecca


    The transition to motherhood in western society is particularly informed by risk-based scientific and medical discourses and, as a result, women are especially subject to rationalities and practices that are employed in the name of risk. The aim of this article is to examine the gendered risk discourses that are embedded in one aspect of medicalized mothering - the postpartum period. This article interrogates three key elements of the discursive construction of postpartum depression (PPD) in contemporary psychiatric research literature (approximately 1980-2007). Specifically, I examine how risk-based reasoning is incorporated into the concepts of the postpartum triad and the high-risk mother, and how arguments about why PPD is a 'significant social problem' create a tension between the rights of the mother and those of the child. By placing women in a position to manage certain types of risks related to the postpartum period, these discourses serve to responsibilize women and structure their subjectivities in gendered ways.This analysis contributes to a growing literature that investigates how assumptions about gender, race, class and sexuality are produced and re-produced through the notion of risk.

  13. The countries and languages that dominate biological research at the beginning of the 21st century

    Directory of Open Access Journals (Sweden)

    Julián Monge-Nájera


    Full Text Available Traditionally,studies of scientific productivity are biased in two ways: they are based on Current Contents, an index centered in British and American journals, and they seldom correct for population size, ignoring the relative effort that each society places in research. We studied national productivity for biology using a more representative index, the Biological Abstracts, and analyzed both total and relative productivity. English dominates biological publications with 87% (no other individual language reaches 2%. If the USA is considered a region by itself, it occupies the first place in per capita production of biology papers, with at least twice the productivity of either Asia or Europe. Canada, Oceania and Latin America occupy an intermediate position. The global output of scientific papers is dominated by Europe, USA, Japan, Canada, China and India. When corrected for population size, the countries with the greatest productivity of biology papers are the Nordic nations, Israel, Switzerland, Netherlands, Australia, Saint Lucia and Montserrat. The predominance of English as the language of biological research found in this study shows a continuation of the trend initiated around the year 1900. The large relative productivity of the USA reflects the importance that American society gives to science as the basis for technological and economic development, but the USA’s share of total scientific output has decreased from 44% in 1983 to 34% in 2002, while there is a greater growth of science in India, Japan and Latin America, among others. The increasing share obtained by China and India may reflect a recent change in attitude towards funding science. The leadership of Nordic nations, Israel, Switzerland, Netherlands and Australia can be explained by cultural attitude. Apparently, a positive trend is emerging in Latin America, where Chile improved its ranking in per capita productivity but Argentina, Costa Rica, Uruguay, Brazil and Cuba fell

  14. How will we know "good" qualitative research when we see it? Beginning the dialogue in health services research. (United States)

    Devers, K J


    OBJECTIVE: To lay the foundation for an explicit review and dialogue concerning the criteria that should be used to evaluate qualitative health services research. Clear criteria are critical for the discipline because they provide a benchmark against which research can be assessed. DATA SOURCES: Existing literature in the social sciences and health services research, particularly in primary care and medicine. PRINCIPAL FINDING: Traditional criteria for evaluating qualitative research are rooted in the philosophical perspective (positivism) most closely associated with quantitative research and methods. As a result, qualitative research and methods may not be used as frequently as they can be and research results generated from qualitative studies may not be disseminated as widely as possible. However, alternative criteria for evaluating qualitative research have been proposed that reflect a different philosophical perspective (post-positivism). Moreover, these criteria are tailored to the unique purposes for which qualitative research is used and the research designs traditionally employed. While criteria based on these two different philosophical perspectives have much in common, some important differences exist. CONCLUSION: The field of health services research must engage in a collective, "qualitative" process to determine which criteria to adopt (positivist or post-positivist), or whether some combination of the two is most appropriate. Greater clarity about the criteria used to evaluate qualitative research will strengthen the discipline by fostering a more appropriate and improved use of qualitative methods, a greater willingness to fund and publish "good" qualitative research, and the development of more informed consumers of qualitative research results. Images Figure 1 PMID:10591278

  15. Subjective perceptions of ESP (English for Specific Purposes university teachers’ professional beginnings: Quantitative research into pedagogical content knowledge

    Directory of Open Access Journals (Sweden)

    Jašková Jana


    Full Text Available The aim of this paper is to present methodology and results of a quantitative phase within a research into English for Specific Purposes university teachers and their subjectively perceived changes in pedagogical content knowledge from a retrospective view of their professional beginnings. The introduction describes the investigated issues and explains key concepts. The first chapter refers to the theoretical background of teacher professional development. Since the quantitative research phase is a part of a mixed research design, the second chapter deals with the whole research including the research objective and questions. The third chapter is devoted to the quantitative research phase during which an anonymous electronic questionnaire was sent to the whole population of Czech university teachers of English for Specific Purposes and processed statistically as well as descriptively. The fourth chapter presents the obtained quantitative data discussed within the individual components of pedagogical content knowledge - conceptions of purposes for teaching subject matter, curricular knowledge, knowledge of instructional strategies, and knowledge of students’ understanding. The conclusion summarises all the information and proposes some recommendations for pedagogical practice.

  16. Beginning C

    CERN Document Server

    Horton, Ivor


    Beginning C, 5th Edition teaches you how to program using the widely-available C language. You'll begin from first-principles and progress through step-by-step examples to become a competent, C-language programmer. All you need are this book and any of the widely available free or commercial C or C++ compilers, and you'll soon be writing real C programs. C is a foundational language that every programmer ought to know. C is the basis for C# used in Microsoft .NET programming. It is the basis for Objective-C used in programming for the iPhone, the iPad, and other Apple devices. It is the basis

  17. Multicatalyst system in asymmetric catalysis

    CERN Document Server

    Zhou, Jian


    This book introduces multi-catalyst systems by describing their mechanism and advantages in asymmetric catalysis.  Helps organic chemists perform more efficient catalysis with step-by-step methods  Overviews new concepts and progress for greener and economic catalytic reactions  Covers topics of interest in asymmetric catalysis including bifunctional catalysis, cooperative catalysis, multimetallic catalysis, and novel tandem reactions   Has applications for pharmaceuticals, agrochemicals, materials, and flavour and fragrance

  18. Catalysis of Supramolecular Hydrogelation

    NARCIS (Netherlands)

    Trausel, F.; Versluis, F.; Maity, C.; Poolman, J.M.; Lovrak, M.; van Esch, J.H.; Eelkema, R.


    ConspectusOne often thinks of catalysts as chemical tools to accelerate a reaction or to have a reaction run under more benign conditions. As such, catalysis has a role to play in the chemical industry and in lab scale synthesis that is not to be underestimated. Still, the role of catalysis in

  19. Kinetics and Catalysis Demonstrations. (United States)

    Falconer, John L.; Britten, Jerald A.


    Eleven videotaped kinetics and catalysis demonstrations are described. Demonstrations include the clock reaction, oscillating reaction, hydrogen oxidation in air, hydrogen-oxygen explosion, acid-base properties of solids, high- and low-temperature zeolite reactivity, copper catalysis of ammonia oxidation and sodium peroxide decomposition, ammonia…

  20. Beginning Spring

    CERN Document Server

    Caliskan, Mert


    Get up to speed quickly with this comprehensive guide toSpring Beginning Spring is the complete beginner's guide toJava's most popular framework. Written with an eye towardreal-world enterprises, the book covers all aspects of applicationdevelopment within the Spring Framework. Extensive samples withineach chapter allow developers to get up to speed quickly byproviding concrete references for experimentation, building askillset that drives successful application development byexploiting the full capabilities of Java's latest advances. Spring provides the exact toolset required to build anent

  1. Beginning Scala

    CERN Document Server

    Pollak, David


    The open source Scala language is a Java--based dynamic scripting, functional programming language. Moreover, this highly scalable scripting language lends itself well to building Cloud--based/deliverable Software as a Service (SaaS) online applications. Written by Lift Scala web framework founder and lead Dave Pollak, Beginning Scala takes a down--to--earth approach to teaching Scala that leads you through simple examples that can be combined to build complex, scalable systems and applications. This book introduces you to the Scala programming language and then guides you through Scala constr

  2. Beginning Perl

    CERN Document Server

    Poe, Curtis 'Ovid'


    Everything beginners need to start programming with Perl Perl is the ever-popular, flexible, open source programming language that has been called the programmers’ Swiss army knife. This book introduces Perl to both new programmers and experienced ones who are looking to learn a new language. In the tradition of the popular Wrox Beginning guides, it presents step-by-step guidance in getting started, a host of try-it-out exercises, real-world examples, and everything necessary for a Perl novice to start programming with confidence. Introduces Perl to both new programmers and experienced o

  3. Beginning Hibernate

    CERN Document Server

    Minter, Dave; Ottinger, Joseph


    Beginning Hibernate, Third Edition is ideal if you're experienced in Java with databases (the traditional, or "connected," approach), but new to open-source, lightweight Hibernate, a leading object-relational mapping and database-oriented application development framework.This book packs in information about the release of the Hibernate 4.x persistence layer and provides a clear introduction to the current standard for object-relational persistence in Java. And since the book keeps its focus on Hibernate without wasting time on nonessential third-party tools, you'll be able to immediately star

  4. Beginning Hibernate

    CERN Document Server

    Linwood, Jeff


    Beginning Hibernate, Second Edition is ideal if you're experienced in Java with databases (the traditional, or "connected," approach), but new to open source, lightweight Hibernate-the de facto object-relational mapping and database-oriented application development framework. This book packs in brand-new information about the latest release of the Hibernate 3.5 persistence layer and provides a clear introduction to the current standard for object-relational persistence in Java. And since the book keeps its focus on Hibernate without wasting time on nonessential third-party tools, you

  5. Beginning F#

    CERN Document Server

    Pickering, Robert


    Functional programming is perhaps the next big wave in application development. As experienced developers know, functional programming makes its mark by allowing application builders to develop solutions to complicated programming situations cleanly and efficiently. A rich history of functional languages, including Erlang and OCaml, leads the way to F#, Microsoft's effort to bring the elegance and focus of functional programming into the world of managed code and .NET. With Beginning F#, you have a companion that that will help you explore F# and functional programming in a .NET environment. T

  6. Faraday Discussions meeting Catalysis for Fuels. (United States)

    Fischer, Nico; Kondrat, Simon A; Shozi, Mzamo


    Welcome to Africa was the motto when after more than 100 years the flag ship conference series of the Royal Society of Chemistry, the Faraday Discussions was hosted for the first time on the African Continent. Under the fitting topic 'Catalysis for Fuels' over 120 delegates followed the invitation by the conference chair Prof. Graham Hutchings FRS (Cardiff Catalysis Institute), his organizing committee and the co-organizing DST-NRF Centre of Excellence in Catalysis c*change (). In the presentations of 21 invited speakers and 59 posters, cutting edge research in the field of catalysis for fuels, designing new catalysts for synthetic fuels, hydrocarbon conversion in the production of synthetic fuels and novel photocatalysis was presented over the two-day meeting. The scene was set by the opening lecture of Prof. Enrique Iglesias (UC Berkeley) and wrapped-up with the concluding remarks by Philip Gibson (SASOL).

  7. Surface and nanomolecular catalysis

    CERN Document Server

    Richards, Ryan


    Using new instrumentation and experimental techniques that allow scientists to observe chemical reactions and molecular properties at the nanoscale, the authors of Surface and Nanomolecular Catalysis reveal new insights into the surface chemistry of catalysts and the reaction mechanisms that actually occur at a molecular level during catalysis. While each chapter contains the necessary background and explanations to stand alone, the diverse collection of chapters shows how developments from various fields each contributed to our current understanding of nanomolecular catalysis as a whole. The

  8. Molecular water oxidation catalysis

    CERN Document Server

    Llobet, Antoni


    Photocatalytic water splitting is a promising strategy for capturing energy from the sun by coupling light harvesting and the oxidation of water, in order to create clean hydrogen fuel. Thus a deep knowledge of the water oxidation catalysis field is essential to be able to come up with useful energy conversion devices based on sunlight and water splitting. Molecular Water Oxidation Catalysis: A Key Topic for New Sustainable Energy Conversion Schemes presents a comprehensive and state-of-the-art overview of water oxidation catalysis in homogeneous phase, describing in detail the most importan

  9. Catalysis in the Primordial World

    Directory of Open Access Journals (Sweden)

    Nenad Raos


    Full Text Available Catalysis provides orderly prebiotic synthesis and eventually its evolution into autocatalytic (self-reproduction systems. Research on homogeneous catalysis is concerned mostly with random peptide synthesis and the chances to produce catalytic peptide oligomers. Synthesis of ribose via formose reaction was found to be catalysed by B(OH4−, presumably released by weathering of borate minerals. Oxide and clay mineral surfaces provide catalytic sites for the synthesis of oligopeptides and oligonucleotides. Chemoautotrophic or iron-sulphur-world theory assumes that the first (pioneer organisms developed by catalytic processes on (Fe/NiS particles formed near/close hydrothermal vents. The review provides an overlay of possible catalytic reactions in prebiotic environment, discussing their selectivity (regioselectivity, stereoselectivity as well as geological availability of catalytic minerals and geochemical conditions enabling catalytic reactions on early Earth.

  10. Nano catalysis: Academic Discipline and Industrial Realities

    International Nuclear Information System (INIS)

    Olveira, S.; Forster, S.P.; Seeger, S.


    Nano technology plays a central role in both academic research and industrial applications. Nano enabled products are not only found in consumer markets, but also importantly in business to business markets (B2B). One of the oldest application areas of nano technology is nano catalysis—an excellent example for such a B2 B market. Several existing reviews illustrate the scientific developments in the field of nano catalysis. The goal of the present review is to provide an up-to-date picture of academic research and to extend this picture by an industrial and economic perspective. We therefore conducted an extensive search on several scientific databases and we further analyzed more than 1,500 nano catalysis-related patents and numerous market studies. We found that scientists today are able to prepare nano catalysts with superior characteristics regarding activity, selectivity, durability, and recoverability, which will contribute to solve current environmental, social, and industrial problems. In industry, the potential of nano catalysis is recognized, clearly reflected by the increasing number of nano catalysis-related patents and products on the market. The current nano catalysis research in academic and industrial laboratories will therefore enable a wealth of future applications in the industry

  11. Homogeneous, Heterogeneous, and Enzymatic Catalysis. (United States)

    Oyama, S. Ted; Somorjai, Gabor A.


    Discusses three areas of catalysis: homegeneous, heterogeneous, and enzymatic. Explains fundamentals and economic impact of catalysis. Lists and discusses common industrial catalysts. Provides a list of 107 references. (MVL)

  12. Catalysis for alternative energy generation

    CERN Document Server


    Summarizes recent problems in using catalysts in alternative energy generation and proposes novel solutions  Reconsiders the role of catalysis in alternative energy generation  Contributors include catalysis and alternative energy experts from across the globe

  13. Catalysis induced by radiations

    International Nuclear Information System (INIS)

    Jimenez B, J.; Gonzalez J, J. C.


    In Mexico is generated a great quantity of residuals considered as dangerous, for its capacity of corrosion, reactivity, toxicity to the environment, inflammability and biological-infectious potential. It is important to mention that the toxic compounds cannot be discharged to the sewerage systems and much less to the receiving bodies of water. The usual treatment that receives the dangerous residuals is the incineration and the bordering. The incineration is an efficient form of treating the residuals, but it can be dioxins source and benzofurans, being the phenol and chloro phenol the precursors of these compounds. At the present time the radiolytic degradation of organic compounds has been broadly studied, especially the 4-chloro phenol and of same form the photo catalysis of organic compounds. However the combination of both processes, called radio catalysis is barely reported. In this work the results of the experiments realized for to degrade the 4-chloro phenol by means of radio catalysis are reported. (Author)

  14. Photo-catalysis Plants from basic research to commercial reality; Plantas de tratamiento mediante fotocatalisis solar: de la investigacion basica a una realidad comercial

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, J.; Malato, S.


    The degradation process of nonbiodegradable organic substances by means of photo catalysis techniques allows the effective elimination of pollutants presents in water and air. The development during the last years of the solar photo catalysis technology, commonly called solar detoxification, has allowed that the first commercial plants based on solar collectors for the treatment of waste water containing persistent organic compounds become a reality. CIEMAT has played an essential roll on this process. This technology is based on the application of two different techniques (photo-Fenton and UV/TiO{sub 2} processes) implemented in static solar collectors CPC type (parabolic-compound). (Author)

  15. Cellulose conversion under heterogeneous catalysis. (United States)

    Dhepe, Paresh L; Fukuoka, Atsushi


    In view of current problems such as global warming, high oil prices, food crisis, stricter environmental laws, and other geopolitical scenarios surrounding the use of fossil feedstocks and edible resources, the efficient conversion of cellulose, a non-food biomass, into energy, fuels, and chemicals has received much attention. The application of heterogeneous catalysis could allow researchers to develop environmentally benign processes that lead to selective formation of value-added products from cellulose under relatively mild conditions. This Minireview gives insight into the importance of biomass utilization, the current status of cellulose conversion, and further transformation of the primary products obtained.

  16. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ


    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  17. Green chemistry by nano-catalysis

    KAUST Repository

    Polshettiwar, Vivek


    Nano-materials are important in many diverse areas, from basic research to various applications in electronics, biochemical sensors, catalysis and energy. They have emerged as sustainable alternatives to conventional materials, as robust high surface area heterogeneous catalysts and catalyst supports. The nano-sized particles increase the exposed surface area of the active component of the catalyst, thereby enhancing the contact between reactants and catalyst dramatically and mimicking the homogeneous catalysts. This review focuses on the use of nano-catalysis for green chemistry development including the strategy of using microwave heating with nano-catalysis in benign aqueous reaction media which offers an extraordinary synergistic effect with greater potential than these three components in isolation. To illustrate the proof-of-concept of this "green and sustainable" approach, representative examples are discussed in this article. © 2010 The Royal Society of Chemistry.

  18. Age and cause mortality structure in the Italian regions at the beginning of the health transition: a research

    Directory of Open Access Journals (Sweden)

    Lorenzo Del Panta


    Full Text Available This paper aims at exploring Italian mortality structure (by age and cause of death at the regional level in the last decades of the 19th Century. These years, corresponding to the beginning of the health transition process, were crucial in the Italian experience. The analysis is based on a careful exploitation of the volume “Statistica delle cause delle morti 1888”, published in 1890, by the General Directorate of Statistics. This volume is the only one which offers for the Italian regions, before the second World war, death statistics classified according to both age and cause together. The principal objectives of this descriptive contribution are essentially to illustrate the territorial variation of mortality conditions in the first phase of the health transition process as well as to underline the relevance and the complexities of the causes specific mortality analysis to explain the geographical mortality differentials in terms of age and sex.

  19. Pollution Control by Catalysis

    DEFF Research Database (Denmark)

    Eriksen, Kim Michael; Fehrmann, Rasmus


    The report summarises the results of two years of collaboration supported by INTAS between Department of Chemistry,DTU,DK , IUSTI,Universite de Provence,FR, ICE/HT University 6of Patras,GR, and Boreskov Institute of Catalysis,RU.The project has been concerned with mechanistic studies of deNOx and...

  20. Anion-π catalysis. (United States)

    Zhao, Yingjie; Beuchat, César; Domoto, Yuya; Gajewy, Jadwiga; Wilson, Adam; Mareda, Jiri; Sakai, Naomi; Matile, Stefan


    The introduction of new noncovalent interactions to build functional systems is of fundamental importance. We here report experimental and theoretical evidence that anion-π interactions can contribute to catalysis. The Kemp elimination is used as a classical tool to discover conceptually innovative catalysts for reactions with anionic transition states. For anion-π catalysis, a carboxylate base and a solubilizer are covalently attached to the π-acidic surface of naphthalenediimides. On these π-acidic surfaces, transition-state stabilizations up to ΔΔGTS = 31.8 ± 0.4 kJ mol(-1) are found. This value corresponds to a transition-state recognition of KTS = 2.7 ± 0.5 μM and a catalytic proficiency of 3.8 × 10(5) M(-1). Significantly increasing transition-state stabilization with increasing π-acidity of the catalyst, observed for two separate series, demonstrates the existence of "anion-π catalysis." In sharp contrast, increasing π-acidity of the best naphthalenediimide catalysts does not influence the more than 12 000-times weaker substrate recognition (KM = 34.5 ± 1.6 μM). Together with the disappearance of Michaelis-Menten kinetics on the expanded π-surfaces of perylenediimides, this finding supports that contributions from π-π interactions are not very important for anion-π catalysis. The linker between the π-acidic surface and the carboxylate base strongly influences activity. Insufficient length and flexibility cause incompatibility with saturation kinetics. Moreover, preorganizing linkers do not improve catalysis much, suggesting that the ideal positioning of the carboxylate base on the π-acidic surface is achieved by intramolecular anion-π interactions rather than by an optimized structure of the linker. Computational simulations are in excellent agreement with experimental results. They confirm, inter alia, that the stabilization of the anionic transition states (but not the neutral ground states) increases with the π-acidity of the

  1. Predictive modeling in homogeneous catalysis: a tutorial

    NARCIS (Netherlands)

    Maldonado, A.G.; Rothenberg, G.


    Predictive modeling has become a practical research tool in homogeneous catalysis. It can help to pinpoint ‘good regions’ in the catalyst space, narrowing the search for the optimal catalyst for a given reaction. Just like any other new idea, in silico catalyst optimization is accepted by some

  2. WE-G-204-02: So You Want to Do Research: Two Approaches to Beginning a Career in Medical Physics Research

    International Nuclear Information System (INIS)

    Deasy, J.


    graduate students who aspire to academic positions with an expectation for extramural funding. To address this, several residency programs have created hybrid programs where the two-years of clinical training is combined with one or two years of research effort to allow candidates to further establish an academic identity and to ensure adequate academic productivity to compete for a beginning faculty position. In conclusion, while the path to a successful career in academic medical physics is steep and sometimes hard to follow, reaching the apex is worth the journey. Different paths to a career in medical physics are available, you just have to decide which one is right for you. If improving cancer care is your goal as a physicist, then academic medical physics is the job for you!

  3. 26 CFR 1.41-4A - Qualified research for taxable years beginning before January 1, 1986. (United States)


    ... research is funded to the extent of the payments (and fair market value of any property) to which the... or depreciable property used in research, and mineral exploration costs described in section 174(d... development of a new life insurance contract, a new economic model or theory, a new accounting procedure or a...

  4. Solid Base Catalysis

    CERN Document Server

    Ono, Yoshio


    The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to whic...

  5. Applied heterogeneous catalysis

    International Nuclear Information System (INIS)

    Le Page, A.J.F.


    This reference book explains the scientific principles of heterogeneous catalysis while also providing details on the methods used to develop commercially viable catalyst products. A section of the book presents reactor design engineering theory and practices for the profitable application of these catalysts in large-scale industrial processes. A description of the mechanisms and commercial applications of catalysis is followed by a review of catalytic reaction kinetics. There are five chapters on selecting catalyst agents, developing and preparing industrial catalysts, measuring catalyst properties, and analyzing the physico-chemical characteristics of solid catalyst particles. The final chapter reviews the elements of catalytic reactor design, with emphasis on flow regimes vs. reactor types, heat and mass transfer in reactor beds, single- and multi-phase flows, and the effects of thermodynamics and other catalyst properties on the process flow scheme

  6. The development of the nuclear physics in Latvia III. The research nuclear reactor IRT begins to work in Latvia

    International Nuclear Information System (INIS)

    Ulmanis, U.


    This article is associated with the study of reactors technical parameters with specific interest on the effect the distribution of neutron and gamma radiation through the reactor's cooling systems has on the environment. Scientist began by implementing monitoring system to assist in the research of nuclear spectroscopy, neutron activation analysis, neutron diffraction, solid-state radiation physics, chemistry and radiobiology. The first sets of results are summarized with in the article. (author)

  7. Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis

    International Nuclear Information System (INIS)

    Overbury, Steven H.; Coates, Leighton; Herwig, Kenneth W.; Kidder, Michelle


    This report summarizes the Workshop on Neutron Scattering Techniques for Studies in Catalysis, held at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) on September 16 and 17, 2010. The goal of the Workshop was to bring experts in heterogeneous catalysis and biocatalysis together with neutron scattering experimenters to identify ways to attack new problems, especially Grand Challenge problems in catalysis, using neutron scattering. The Workshop locale was motivated by the neutron capabilities at ORNL, including the High Flux Isotope Reactor (HFIR) and the new and developing instrumentation at the SNS. Approximately 90 researchers met for 1 1/2 days with oral presentations and breakout sessions. Oral presentations were divided into five topical sessions aimed at a discussion of Grand Challenge problems in catalysis, dynamics studies, structure characterization, biocatalysis, and computational methods. Eleven internationally known invited experts spoke in these sessions. The Workshop was intended both to educate catalyst experts about the methods and possibilities of neutron methods and to educate the neutron community about the methods and scientific challenges in catalysis. Above all, it was intended to inspire new research ideas among the attendees. All attendees were asked to participate in one or more of three breakout sessions to share ideas and propose new experiments that could be performed using the ORNL neutron facilities. The Workshop was expected to lead to proposals for beam time at either the HFIR or the SNS; therefore, it was expected that each breakout session would identify a few experiments or proof-of-principle experiments and a leader who would pursue a proposal after the Workshop. Also, a refereed review article will be submitted to a prominent journal to present research and ideas illustrating the benefits and possibilities of neutron methods for catalysis research.

  8. Neutrons for Catalysis: A Workshop on Neutron Scattering Techniques for Studies in Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Overbury, Steven {Steve} H [ORNL; Coates, Leighton [ORNL; Herwig, Kenneth W [ORNL; Kidder, Michelle [ORNL


    This report summarizes the Workshop on Neutron Scattering Techniques for Studies in Catalysis, held at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) on September 16 and 17, 2010. The goal of the Workshop was to bring experts in heterogeneous catalysis and biocatalysis together with neutron scattering experimenters to identify ways to attack new problems, especially Grand Challenge problems in catalysis, using neutron scattering. The Workshop locale was motivated by the neutron capabilities at ORNL, including the High Flux Isotope Reactor (HFIR) and the new and developing instrumentation at the SNS. Approximately 90 researchers met for 1 1/2 days with oral presentations and breakout sessions. Oral presentations were divided into five topical sessions aimed at a discussion of Grand Challenge problems in catalysis, dynamics studies, structure characterization, biocatalysis, and computational methods. Eleven internationally known invited experts spoke in these sessions. The Workshop was intended both to educate catalyst experts about the methods and possibilities of neutron methods and to educate the neutron community about the methods and scientific challenges in catalysis. Above all, it was intended to inspire new research ideas among the attendees. All attendees were asked to participate in one or more of three breakout sessions to share ideas and propose new experiments that could be performed using the ORNL neutron facilities. The Workshop was expected to lead to proposals for beam time at either the HFIR or the SNS; therefore, it was expected that each breakout session would identify a few experiments or proof-of-principle experiments and a leader who would pursue a proposal after the Workshop. Also, a refereed review article will be submitted to a prominent journal to present research and ideas illustrating the benefits and possibilities of neutron methods for catalysis research.

  9. Inorganic Reaction Mechanisms Part II: Homogeneous Catalysis (United States)

    Cooke, D. O.


    Suggests several mechanisms for catalysis by metal ion complexes. Discusses the principal factors of importance in these catalysis reactions and suggests reactions suitable for laboratory study. (MLH)

  10. The Beginning of Biochemistry

    Indian Academy of Sciences (India)

    Keywords. Fermentation; enzymes; catalysis; proteins; biochemistry. Author Affiliations. T Ramasarma1. INSA Honorary Scientist Solid State and Structural Chemistry Unit and Department of Biochemistry Indian Institute of Science Bangalore 560 012, India. Resonance – Journal of Science Education. Current Issue : Vol.

  11. Metallic nanosystems in catalysis

    International Nuclear Information System (INIS)

    Bukhtiyarov, Valerii I; Slin'ko, Mikhail G


    The reactivities of metallic nanosystems in catalytic processes are considered. The activities of nanoparticles in catalysis are due to their unique microstructures, electronic properties and high specific surfaces of the active centres. The problems of increasing the selectivities of catalytic processes are discussed using several nanosystems as examples. The mutual effects of components of bimetallic nanoparticles are discussed. The prospects for theoretical and experimental investigations into catalytic nanosystems and the construction of industrial catalysts based on them are evaluated. The bibliography includes 207 references.

  12. Concepts in Heterogeneous Catalysis (United States)


    Cordew, (;, Paw anW C, T. H. Stoddart , J. Am, Chem. Soc,, 3 6272 (1960). 919R. L. Burwell, G, L. Hailer, K. C, Taylor. and J. F. Read, Advances in...1969). Burwell, R. L., A. B. Littlewood, M. Cordew, G. Pass, and C. T. H. Stoddart , J. Am, Chem. Soc., 82 (1960). Burwell, R, L. and C. J. Loner, Proc... Hannah , Ed., ACS Monograph 140, chapter 14, Reinhold, New York 1959. Moro.oka, Y., Y. Morikawa, and A. Osaki, J. Catalysis, 7 (1967). Moro.oka, Y. and A

  13. Catalysis and prebiotic RNA synthesis (United States)

    Ferris, James P.


    The essential role of catalysis for the origins of life is discussed. The status of the prebiotic synthesis of 2',5'- and 3'5'-linked oligomers of RNA is reviewed. Examples of the role of metal ion and mineral catalysis in RNA oligomer formation are discussed.

  14. Graphitic carbon nitride "reloaded": emerging applications beyond (photo)catalysis. (United States)

    Liu, Jian; Wang, Hongqiang; Antonietti, Markus


    Despite being one of the oldest materials described in the chemical literature, graphitic carbon nitride (g-C3N4) has just recently experienced a renaissance as a highly active photocatalyst, and the metal-free polymer was shown to be able to generate hydrogen under visible light. The semiconductor nature of g-C3N4 has triggered tremendous endeavors on its structural manipulation for enhanced photo(electro)chemical performance, aiming at an affordable clean energy future. While pursuing the stem of g-C3N4 related catalysis (photocatalysis, electrocatalysis and photoelectrocatalysis), a number of emerging intrinsic properties of g-C3N4 are certainly interesting, but less well covered, and we believe that these novel applications outside of conventional catalysis can be favorably exploited as well. Thanks to the general efforts devoted to the exploration and enrichment of g-C3N4 based chemistry, the boundaries of this area have been possibly pushed far beyond what people could imagine in the beginning. This review strives to cover the achievements of g-C3N4 related materials in these unconventional application fields for depicting the broader future of these metal-free and fully stable semiconductors. This review starts with the general protocols to engineer g-C3N4 micro/nanostructures for practical use, and then discusses the newly disclosed applications in sensing, bioimaging, novel solar energy exploitation including photocatalytic coenzyme regeneration, templating, and carbon nitride based devices. Finally, we attempt an outlook on possible further developments in g-C3N4 based research.

  15. Practical Engineering Aspects of Catalysis in Microreactors

    Czech Academy of Sciences Publication Activity Database

    Křišťál, Jiří; Stavárek, Petr; Vajglová, Zuzana; Vondráčková, Magdalena; Pavlorková, Jana; Jiřičný, Vladimír


    Roč. 41, č. 12 (2015), s. 9357-9371 ISSN 0922-6168. [Pannonian Symposium on Catalysis /12./. Castle Trest, 16.09.2014-20.09.2014] Institutional support: RVO:67985858 Keywords : heterogeneous catalysis * homogeneous catalysis * photo catalysis Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.833, year: 2015

  16. Simulations of chemical catalysis (United States)

    Smith, Gregory K.

    This dissertation contains simulations of chemical catalysis in both biological and heterogeneous contexts. A mixture of classical, quantum, and hybrid techniques are applied to explore the energy profiles and compare possible chemical mechanisms both within the context of human and bacterial enzymes, as well as exploring surface reactions on a metal catalyst. A brief summary of each project follows. Project 1 - Bacterial Enzyme SpvC The newly discovered SpvC effector protein from Salmonella typhimurium interferes with the host immune response by dephosphorylating mitogen-activated protein kinases (MAPKs) with a beta-elimination mechanism. The dynamics of the enzyme substrate complex of the SpvC effector is investigated with a 3.2 ns molecular dynamics simulation, which reveals that the phosphorylated peptide substrate is tightly held in the active site by a hydrogen bond network and the lysine general base is positioned for the abstraction of the alpha hydrogen. The catalysis is further modeled with density functional theory (DFT) in a truncated active-site model at the B3LYP/6-31 G(d,p) level of theory. The truncated model suggested the reaction proceeds via a single transition state. After including the enzyme environment in ab initio QM/MM studies, it was found to proceed via an E1cB-like pathway, in which the carbanion intermediate is stabilized by an enzyme oxyanion hole provided by Lys104 and Tyr158 of SpvC. Project 2 - Human Enzyme CDK2 Phosphorylation reactions catalyzed by kinases and phosphatases play an indispensable role in cellular signaling, and their malfunctioning is implicated in many diseases. Ab initio quantum mechanical/molecular mechanical studies are reported for the phosphoryl transfer reaction catalyzed by a cyclin-dependent kinase, CDK2. Our results suggest that an active-site Asp residue, rather than ATP as previously proposed, serves as the general base to activate the Ser nucleophile. The corresponding transition state features a

  17. Magnetic catalysis and inverse magnetic catalysis in QCD

    International Nuclear Information System (INIS)

    Mueller, N.


    We investigate the effects of strong magnetic fields on the QCD phase structure at vanishing density by solving the gluon and quark gap equations. The chiral crossover temperature as well as the chiral condensate is computed. For asymptotically large magnetic fields we find magnetic catalysis, while we find inverse magnetic catalysis for intermediate magnetic fields. Moreover, for large magnetic fields the chiral phase transition for massless quarks turns into a crossover. The underlying mechanisms are then investigated analytically within a few simplifications of the full numerical analysis. We find that a combination of gluon screening effects and the weakening of the strong coupling is responsible for the phenomenon of inverse catalysis seen in lattice studies. In turn, the magnetic catalysis at large magnetic field is already indicated by simple arguments based on dimensionality. (author)

  18. Asymmetric trienamine catalysis: new opportunities in amine catalysis. (United States)

    Kumar, Indresh; Ramaraju, Panduga; Mir, Nisar A


    Amine catalysis, through HOMO-activating enamine and LUMO-activating iminium-ion formation, is receiving increasing attention among other organocatalytic strategies, for the activation of unmodified carbonyl compounds. Particularly, the HOMO-raising activation concept has been applied to the greatest number of asymmetric transformations through enamine, dienamine, and SOMO-activation strategies. Recently, trienamine catalysis, an extension of amine catalysis, has emerged as a powerful tool for synthetic chemists with a novel activation strategy for polyenals/polyenones. In this review article, we discuss the initial developments of trienamine catalysis for highly asymmetric Diels-Alder reactions with different dienophiles and emerging opportunities for other types of cycloadditions and cascade reactions.

  19. Recent Advances in Supramolecular Gels and Catalysis. (United States)

    Fang, Weiwei; Zhang, Yang; Wu, Jiajie; Liu, Cong; Zhu, Haibo; Tu, Tao


    Over the past two decades, supramolecular gels have attracted significant attention from scientists in diverse research fields and have been extensively developed. This review mainly focuses on the significant achievements in supramolecular gels and catalysis. First, by incorporating diverse catalytic sites and active organic functional groups into gelator molecules, supramolecular gels have been considered as a novel matrix for catalysis. In addition, these rationally designed supramolecular gels also provide a variety of templates to access metal nanocomposites, which may function as catalysts and exhibit high activity in diverse catalytic transformations. Finally, as a new kind of biomaterial, supramolecular gels formed in situ by self-assembly triggered by catalytic transformations are also covered herein. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Teaching Beginning Trombone Players. (United States)

    Fallis, Todd L.


    Discusses the process of introducing the trombone to beginning students and addresses the issue of warming-up. Provides resources for beginning trombone methods, band methods, and daily warm-up studies. Includes resources for scale studies and etudes for beginning to intermediate trombone players. (CMK)

  1. DNA-based hybrid catalysis. (United States)

    Rioz-Martínez, Ana; Roelfes, Gerard


    In the past decade, DNA-based hybrid catalysis has merged as a promising novel approach to homogeneous (asymmetric) catalysis. A DNA hybrid catalysts comprises a transition metal complex that is covalently or supramolecularly bound to DNA. The chiral microenvironment and the second coordination sphere interactions provided by the DNA are key to achieve high enantioselectivities and, often, additional rate accelerations in catalysis. Nowadays, current efforts are focused on improved designs, understanding the origin of the enantioselectivity and DNA-induced rate accelerations, expanding the catalytic scope of the concept and further increasing the practicality of the method for applications in synthesis. Herein, the recent developments will be reviewed and the perspectives for the emerging field of DNA-based hybrid catalysis will be discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. A Survey Course in Catalysis. (United States)

    Skaates, J. M.


    Describes a 10-week survey course in catalysis for chemical engineering and chemistry students designed to show how modern chemistry and chemical engineering interact in the ongoing development of industrial catalysts. Includes course outline and instructional strategies. (Author/JN)

  3. Asymmetric cation-binding catalysis

    DEFF Research Database (Denmark)

    Oliveira, Maria Teresa; Lee, Jiwoong


    solvents, thus increasing their applicability in synthesis. The expansion of this concept to chiral polyethers led to the emergence of asymmetric cation-binding catalysis, where chiral counter anions are generated from metal salts, particularly using BINOL-based polyethers. Alkali metal salts, namely KF...... and KCN, are selectively bound to the catalyst, providing exceptionally high enantioselectivities for kinetic resolutions, elimination reactions (fluoride base), and Strecker synthesis (cyanide nucleophile). Asymmetric cation-binding catalysis was recently expanded to silicon-based reagents, enabling...

  4. Enhanced Micellar Catalysis LDRD.

    Energy Technology Data Exchange (ETDEWEB)

    Betty, Rita G.; Tucker, Mark D; Taggart, Gretchen; Kinnan, Mark K.; Glen, Crystal Chanea; Rivera, Danielle; Sanchez, Andres; Alam, Todd Michael


    The primary goals of the Enhanced Micellar Catalysis project were to gain an understanding of the micellar environment of DF-200, or similar liquid CBW surfactant-based decontaminants, as well as characterize the aerosolized DF-200 droplet distribution and droplet chemistry under baseline ITW rotary atomization conditions. Micellar characterization of limited surfactant solutions was performed externally through the collection and measurement of Small Angle X-Ray Scattering (SAXS) images and Cryo-Transmission Electron Microscopy (cryo-TEM) images. Micellar characterization was performed externally at the University of Minnesotas Characterization Facility Center, and at the Argonne National Laboratory Advanced Photon Source facility. A micellar diffusion study was conducted internally at Sandia to measure diffusion constants of surfactants over a concentration range, to estimate the effective micelle diameter, to determine the impact of individual components to the micellar environment in solution, and the impact of combined components to surfactant phase behavior. Aerosolized DF-200 sprays were characterized for particle size and distribution and limited chemical composition. Evaporation rates of aerosolized DF-200 sprays were estimated under a set of baseline ITW nozzle test system parameters.

  5. Prebiotic Organometallic Catalysis (United States)

    Peters, J. W.; Cody, G.; Russell, M.; Ferry, J. G.; Schoonen, M. A. A.


    We are at the beginning of a renaissance period where integrated efforts can provide rapid advances in the our understanding of the relationships between abiocatalysis and biocatalysis by transition metal sulfide clusters/minerals in the context of the origin of life.

  6. How do relationships begin?

    NARCIS (Netherlands)

    Holmen, Elsebeth; Roos, Kaspar; Kallevag, Magne; von Raesfeld Meijer, Ariane M.; de Boer, L.; Pedersen, Ann-Charlott


    In this paper we address the issue ‘How do relationships begin?’ Based on a review of work within theIMP Approach on stage and state models of relationship evolution, we conclude that very littleattention has been paid to beginnings of relationships. We discuss why this might be so, and why theissue

  7. The beginning of human life (United States)


    Introduction The Jewish religion is characterized by a strict association between faith and practical precept. Jewish law has two sections, the written and the oral tradition. The foundation of the written law and the origin of authority is the Torah, the first five books of the Scripture. It is an expression of God’s revelation, teaching and guiding humanity. The oral laws interpret, expand, and elucidate the written Torah and behavior patterns regulate new rules and customs. The main parts of the oral law are as follows: the Mishnah, the Talmud, Post-Talmudic Codes and. Responsa Literature. Discussion Life is a process that has a beginning and an end. The consensus about the time when human life really begins is still not reached among scientists, philosophers, ethicists, sociologists and theologizes. The scientific data suggested that a single developmental moment marking the beginning of human life does not exist. Current biological perspectives on when human life begins range through fertilization, gastrulation, to birth and even after. The development of a newborn is a smoothly continuous process. Results Procreation is acknowledged in the Bible to be the gift of God. The (Halachic) Jewish interpretation of when human life begins is extracted predominantly from procreation is acknowledged in the Bible to be the gift of God. The Jewish interpretation of when human life begins is extracted predominantly from The Halachic sources. The Bible does not make any other direct references regarding the beginning of human life. Conclusion While the Talmud gives the full status of humanness to a child at birth, the rabbinical writings have partially extended the acquisition of humanness to the 13th postnatal day of life for full-term infants. The Babylonian Talmud Yevamot 69b states that: “the embryo is considered to be mere water until the fortieth day.” Afterwards, it is considered subhuman until it is born. The issues of abortion, embryo research, multifetal

  8. Francois Garin: Pioneer work in catalysis through synchrotron radiation

    International Nuclear Information System (INIS)

    Bazin, Dominique


    Starting from the late seventies, the progressively increased availability of beamlines dedicated to X-ray absorption spectroscopy allowed the execution of experiments in chemistry. In this manuscript, I describe the contribution of Francois Garin at the frontier of heterogeneous catalysis and synchrotron radiation. Working at LURE as a scientific in charge of a beamline dedicated to X-ray absorption spectroscopy during almost twenty years and thus, having the opportunity to discuss with research groups working in heterogeneous catalysis in Europe as well as in the United States, it was quite easy to show that his work is clearly at the origin of current research in heterogeneous catalysis, not only in France, but in different synchrotron radiation centres. (authors)

  9. Stress Controlled Catalysis via Engineered Nanostructures (United States)


    fields on catalysis : “Stress Controlled Catalysis via Engineered Nanostructures.” For this effort a workshop was organized and held at Brown... Catalysis via Engineered Nanostructures" The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued...Support for current award "Stress Controlled Catalysis via Engineered Nanostructures" Report Title This is the final report of the ARO project of

  10. Catalysis and sustainable (green) chemistry

    Energy Technology Data Exchange (ETDEWEB)

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


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

  11. Aromatic Chlorosulfonylation by Photoredox Catalysis. (United States)

    Májek, Michal; Neumeier, Michael; Jacobi von Wangelin, Axel


    Visible-light photoredox catalysis enables the efficient synthesis of arenesulfonyl chlorides from anilines. The new protocol involves the convenient in situ preparation of arenediazonium salts (from anilines) and the reactive gases SO 2 and HCl (from aqueous SOCl 2 ). The photocatalytic chlorosulfonylation operates at mild conditions (room temperature, acetonitrile/water) with low catalyst loading. Various functional groups are tolerated (e.g., halides, azides, nitro groups, CF 3 , SF 5 , esters, heteroarenes). Theoretical and experimental studies support a photoredox-catalysis mechanism. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Photoredox Catalysis in Organic Chemistry (United States)


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

  13. KCC1: First Nanoparticle developed by KAUST Catalysis Center

    KAUST Repository

    Basset, Jean-Marie


    KCC1 is the first Nanoparticle developed by KAUST Catalysis Center. Director of KAUST Catalysis Center, Dr. Jean-Marie Basset, Senior Research Scientist at KCC, Dr. Vivek Polshettiwar, and Dr. Dongkyu Cha of the Advanced Nanofabrication Imaging & Characterization Core Laboratory discuss the details of this recent discovery. This video was produced by KAUST Visualization Laboratory and KAUST Technology Transfer and Innovation - Terence McElwee, Director, Technology Transfer and Innovation - This technology is part of KAUST\\'s technology commercialization program that seeks to stimulate development and commercial use of KAUST-developed technologies. For more information email us at

  14. DNA-based asymmetric catalysis

    NARCIS (Netherlands)

    Boersma, Arnold J.; Megens, Rik P.; Feringa, Ben L.; Roelfes, Gerard


    The unique chiral structure of DNA has been a source of inspiration for the development of a new class of bio-inspired catalysts. The novel concept of DNA-based asymmetric catalysis, which was introduced only five years ago, has been applied successfully in a variety of catalytic enantioselective

  15. Transition Metal Complexes and Catalysis

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 9. Transition Metal Complexes and Catalysis. Balaji R Jagirdar. General Article Volume 4 Issue 9 ... Author Affiliations. Balaji R Jagirdar1. Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.

  16. Molecular Mechanism of Heterogeneous Catalysis

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 6. Molecular Mechanism of Heterogeneous Catalysis - The 2007 Nobel Prize in Chemistry. R S Swathi K L Sebastian. General Article Volume 13 Issue 6 June 2008 pp 548-560 ...

  17. A conceptual translation of homogeneous catalysis into heterogeneous catalysis: homogeneous-like heterogeneous gold nanoparticle catalyst induced by ceria supporter. (United States)

    Li, Zhen-Xing; Xue, Wei; Guan, Bing-Tao; Shi, Fu-Bo; Shi, Zhang-Jie; Jiang, Hong; Yan, Chun-Hua


    Translation of homogeneous catalysis into heterogeneous catalysis is a promising solution to green and sustainable development in chemical industry. For this purpose, noble metal nanoparticles represent a new frontier in catalytic transformations. Many challenges remain for researchers to transform noble metal nanoparticles of heterogeneous catalytic active sites into ionic species of homogeneous catalytic active sites. We report here a successful design on translating homogeneous gold catalysis into a heterogeneous system with a clear understanding of the catalytic pathway. This study initiates a novel concept to immobilize a homogeneous catalyst based on electron transfer between supporting base and supported nanoparticles. Meanwhile, on the basis of theoretical calculation, it has deepened the understanding of the interactions between noble metal nanoparticles and the catalyst support.

  18. Applied homogeneous catalysis; Angewandte homogene Katalyse

    Energy Technology Data Exchange (ETDEWEB)

    Behr, Arno [Dortmund Univ. (Germany). Lehrstuhl fuer Technische Chemie A


    In the book under consideration, all persons which are interested in the homogeneous transition metal catalysis and their application in the chemical technology find a practice-orientated and didactically skilled worked-up introduction. This book is addressed to students in the training and also to practicians in occupation. Apart from the chemical fundamentals concerning to the homogeneous catalysis, also fundamentals of process engineering as well as homogeneous catalytic reactions are described. Typical homogeneous catalyzed reactions are hydroformylation, carbonylation, oligomerization and polymerization, metathesis, hydrogenations as well as oxidation reactions. Additionally, new trends in the homogeneous catalysis are described such as tandem reactions, combinatorial chemistry, high throughput catalyst testing, green solvents, activation of paraffines, activation of nitrogen, efficient ligands, nano-catalysis, homogeneous catalysis with regenerating raw materials, process development belong to electrical catalysis / sono-catalysis / photocatalysis / microwave irradiation / maximum pressure.

  19. Pincer-porphyrin hybrids : Synthesis, self-assembly, and catalysis

    NARCIS (Netherlands)

    Suijkerbuijk, B.M.J.M.


    Metal complexes play an important role in established research areas such as catalysis and materials chemistry as well as in emerging fields of chemical exploration such as bioinorganic chemistry. Changes in the metal center's ligand environment, i.e., the nature and number of the Lewis basic atoms

  20. Beginning Ubuntu Linux

    CERN Document Server

    Raggi, Emilio; Channelle, Andy; Parsons, Trevor; Van Vugt, Sander


    Ubuntu Linux is the fastest growing Linux-based operating system, and Beginning Ubuntu Linux, Fifth Edition teaches all of us - including those who have never used Linux - how to use it productively, whether you come from Windows or the Mac or the world of open source. Beginning Ubuntu Linux, Fifth Edition shows you how to take advantage of the newest Ubuntu release, Lucid Lynx. Based on the best-selling previous edition, Emilio Raggi maintains a fine balance between teaching Ubuntu and introducing new features. Whether you aim to use it in the home or in the office, you'll be introduced to th

  1. Beginning Microsoft Excel 2010

    CERN Document Server

    Katz, Abbott


    Beginning Microsoft Excel 2010 is a practical, step-by-step guide to getting started with the world's most widely used spreadsheet application. The book offers a hands-on approach to learning how to create and edit spreadsheets, use various calculation formulas, employ charts/graphs, and get work done efficiently. Microsoft is rolling out several new features with Excel 2010 - perhaps the most notable is the ability to use Excel 2010 online and this collaborate on a project in real time. Beginning Microsoft Office 2010 keeps you up-to-date with all of these new features and more. What you'll l

  2. Beginning Rails 3

    CERN Document Server

    Barazi, Rida Al


    Beginning Rails 3 is the practical starting point for anyone wanting to learn how to build dynamic web applications using the latest release of the Rails framework for Ruby. You'll learn how all of the components of Rails fit together and how you can leverage them to create sophisticated web applications with less code and more joy. This book is particularly well suited to those with little or no experience with web application development, or who have some experience but are new to Rails. Beginning Rails 3 assumes basic familiarity with web terms and technologies, but doesn't require you to b

  3. Molecular catalysis science: Perspective on unifying the fields of catalysis. (United States)

    Ye, Rong; Hurlburt, Tyler J; Sabyrov, Kairat; Alayoglu, Selim; Somorjai, Gabor A


    Colloidal chemistry is used to control the size, shape, morphology, and composition of metal nanoparticles. Model catalysts as such are applied to catalytic transformations in the three types of catalysts: heterogeneous, homogeneous, and enzymatic. Real-time dynamics of oxidation state, coordination, and bonding of nanoparticle catalysts are put under the microscope using surface techniques such as sum-frequency generation vibrational spectroscopy and ambient pressure X-ray photoelectron spectroscopy under catalytically relevant conditions. It was demonstrated that catalytic behavior and trends are strongly tied to oxidation state, the coordination number and crystallographic orientation of metal sites, and bonding and orientation of surface adsorbates. It was also found that catalytic performance can be tuned by carefully designing and fabricating catalysts from the bottom up. Homogeneous and heterogeneous catalysts, and likely enzymes, behave similarly at the molecular level. Unifying the fields of catalysis is the key to achieving the goal of 100% selectivity in catalysis.

  4. Chemical catalysis in biodiesel production (I): enzymatic catalysis processes

    International Nuclear Information System (INIS)

    Jachmarian, I.; Dobroyan, M.; Veira, J.; Vieitez, I.; Mottini, M.; Segura, N.; Grompone, M.


    There are some well known advantages related with the substitution of chemical catalysis by enzymatic catalysis processes.Some commercial immobilized lipases are useful for the catalysis of bio diesel reaction, which permits the achievement of high conversions and the recovery of high purity products, like a high quality glycerine. The main disadvantage of this alternative method is related with the last inactivation of the enzyme (by both the effect of the alcohol and the absorption of glycerol on catalyst surface), which added to the high cost of the catalyst, produces an unfavourable economical balance of the entire process. In the work the efficiency of two commercial immobilized lipases (Lipozyme TL IM y Novozyme 435 NNovozymes-Dinamarca) in the catalysis of the continuous transesterification of sunflower oil with different alcohols was studied. The intersolubility of the different mixturesinvolving reactans (S oil/alkyl esters/alcohol) and products (P mixtures with a higher content of 1% of glycerol,while for ethanol homogeneous mixtures were obtained at 12% of glycerol (44.44 12).Using and ethanolic substrate at the proportion S=19:75:6 and Lipozyme TL IM, it was possible to achieve a 98% of convertion to the corresponding biodiesel.When Novozymes 435 catalyzed the process it was possible to increase the oil concentration in the substrateaccording to proportion S=35:30:35, and a 78% conversion was obtained. The productivity shown by the firt enzyme was 70mg biodiesel g enzime-1, hora-1 while with the second one the productivity increased to 230. Results suggested that the convenient adjustement of substrate composition with the addition of biodiesel to reactants offers an efficient method for maximizing the enzyme productivity, hence improving the profitability of the enzymatic catalyzed process. (author)

  5. Beginning to edit physics

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, P.W.


    A physicist-turned-editor shows you the basics required for copyediting physics papers (physical quantities, symbols, units, scientific notation, the structure of mathematical expressions, the nature of graphs), and points the way to learning enough ``editorial physics`` to begin substantive editing.










  9. Health Begins at Home

    Centers for Disease Control (CDC) Podcasts


    Clean and well-maintained homes can prevent many illnesses and injuries. This podcast discusses how good health begins at home.  Created: 3/30/2009 by Coordinating Center for Environmental Health and Injury Prevention (CCEHIP).   Date Released: 3/30/2009.

  10. Electric Fields and Enzyme Catalysis. (United States)

    Fried, Stephen D; Boxer, Steven G


    What happens inside an enzyme's active site to allow slow and difficult chemical reactions to occur so rapidly? This question has occupied biochemists' attention for a long time. Computer models of increasing sophistication have predicted an important role for electrostatic interactions in enzymatic reactions, yet this hypothesis has proved vexingly difficult to test experimentally. Recent experiments utilizing the vibrational Stark effect make it possible to measure the electric field a substrate molecule experiences when bound inside its enzyme's active site. These experiments have provided compelling evidence supporting a major electrostatic contribution to enzymatic catalysis. Here, we review these results and develop a simple model for electrostatic catalysis that enables us to incorporate disparate concepts introduced by many investigators to describe how enzymes work into a more unified framework stressing the importance of electric fields at the active site.

  11. Magnetic catalysis in nuclear matter (United States)

    Haber, Alexander; Preis, Florian; Schmitt, Andreas


    A strong magnetic field enhances the chiral condensate at low temperatures. This so-called magnetic catalysis thus seeks to increase the vacuum mass of nucleons. We employ two relativistic field-theoretical models for nuclear matter, the Walecka model and an extended linear sigma model, to discuss the resulting effect on the transition between vacuum and nuclear matter at zero temperature. In both models we find that the creation of nuclear matter in a sufficiently strong magnetic field becomes energetically more costly due to the heaviness of magnetized nucleons, even though it is also found that nuclear matter is more strongly bound in a magnetic field. Our results are potentially important for dense nuclear matter in compact stars, especially since previous studies in the astrophysical context have always ignored the contribution of the magnetized Dirac sea and thus the effect of magnetic catalysis.

  12. Virtual Special Issue on Catalysis at the U.S. Department of Energy’s National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Pruski, Marek [Ames Laboratory; Sadow, Aaron D. [Ames Laboratory; Slowing, Igor I. [Ames Laboratory; Marshall, Christopher L. [Argonne National Laboratory; Stair, Peter [Argonne National Laboratory; Rodriguez, Jose [Brookhaven National Laboratory; Harris, Alex [Brookhaven National Laboratory; Somorjai, Gabor A. [Lawrence Berkeley National Laboratory; Biener, Juergen [Lawrence Livermore National Laboratory; Matranga, Christopher [National Energy Technology Laboratory; Wang, Congjun [National Energy Technology Laboratory; Schaidle, Joshua A. [National Renewable Energy Laboratory; Beckham, Gregg T. [National Renewable Energy Laboratory; Ruddy, Daniel A. [National Renewable Energy Laboratory; Deutsch, Todd [National Renewable Energy Laboratory; Alia, Shaun M. [National Renewable Energy Laboratory; Narula, Chaitanya [Oak Ridge National Laboratory; Overbury, Steve [Oak Ridge National Laboratory; Toops, Todd [Oak Ridge National Laboratory; Bullock, R. Morris [Pacific Northwest National Laboratory; Peden, Charles H. F. [Pacific Northwest National Laboratory; Wang, Yong [Pacific Northwest National Laboratory; Allendorf, Mark D. [Sandia National Laboratory; Nørskov, Jens [SLAC National Accelerator Laboratory; Bligaard, Thomas [SLAC National Accelerator Laboratory


    Catalysis research at the U.S. Department of Energy's (DOE's) National Laboratories covers a wide range of research topics in heterogeneous catalysis, homogeneous/molecular catalysis, biocatalysis, electrocatalysis, and surface science. Since much of the work at National Laboratories is funded by DOE, the research is largely focused on addressing DOE's mission to ensure America's security and prosperity by addressing its energy, environmental, and nuclear challenges through transformative science and technology solutions. The catalysis research carried out at the DOE National Laboratories ranges from very fundamental catalysis science, funded by DOE's Office of Basic Energy Sciences (BES), to applied research and development (R&D) in areas such as biomass conversion to fuels and chemicals, fuel cells, and vehicle emission control with primary funding from DOE's Office of Energy Efficiency and Renewable Energy.

  13. Asymmetric Ion-Pairing Catalysis (United States)

    Brak, Katrien


    Charged intermediates and reagents are ubiquitous in organic transformations. The interaction of these ionic species with chiral neutral, anionic, or cationic small molecules has emerged as a powerful strategy for catalytic, enantioselective synthesis. This review describes developments in the burgeoning field of asymmetric ion-pairing catalysis with an emphasis on the insights that have been gleaned into the structural and mechanistic features that contribute to high asymmetric induction. PMID:23192886

  14. Density functional theory in surface science and heterogeneous catalysis

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet; Scheffler, M.; Toulhoat, H.


    Solid surfaces are used extensively as catalysts throughout the chemical industry, in the energy sector, and in environmental protection. Recently, density functional theory has started providing new insight into the atomic-scale mechanisms of heterogeneous catalysis, helping to interpret the large...... amount of experimental data gathered during the last decades. This article shows how density functional theory can be used to describe the state of the surface during reactions and the rate of catalytic reactions. It will also show how we are beginning to understand the variation in catalytic activity...

  15. Ogallala Aquifer Program: A catalysis for research and education to sustain the Ogallala Aquifer on the Southern High Plains (2003-2017) (United States)

    The Ogallala Aquifer Program (OAP) was created in 2003 with support from Congressmen from Kansas and Texas. OAP is a research-education consortium seeking solutions from problems arising from declining water availability from the Ogallala Aquifer in western Kansas and the Texas High Plains. The cons...

  16. Beginning Objective-C

    CERN Document Server

    Dovey, James


    Objective-C is today's fastest growing programming language, at least in part due to the popularity of Apple's Mac, iPhone and iPad. Beginning Objective-C is for you if you have some programming experience, but you're new to the Objective-C programming language and you want a modern-and fast-way forwards to your own coding projects. Beginning Objective-C offers you a modern programmer's perspective on Objective-C courtesy of two of the best iOS and Mac developers in the field today, and gets you programming to the best of your ability in this important language.  It gets you rolling fast into

  17. Beginning algebra a textworkbook

    CERN Document Server

    McKeague, Charles P


    Beginning Algebra: A Text/Workbook, Second Edition focuses on the principles, operations, and approaches involved in algebra. The publication first elaborates on the basics, linear equations and inequalities, and graphing and linear systems. Discussions focus on solving linear systems by graphing, elimination method, graphing ordered pairs and straight lines, linear and compound inequalities, addition and subtraction of real numbers, and properties of real numbers. The text then examines exponents and polynomials, factoring, and rational expressions. Topics include multiplication and division

  18. Beginning partial differential equations

    CERN Document Server

    O'Neil, Peter V


    A broad introduction to PDEs with an emphasis on specialized topics and applications occurring in a variety of fields Featuring a thoroughly revised presentation of topics, Beginning Partial Differential Equations, Third Edition provides a challenging, yet accessible,combination of techniques, applications, and introductory theory on the subjectof partial differential equations. The new edition offers nonstandard coverageon material including Burger's equation, the telegraph equation, damped wavemotion, and the use of characteristics to solve nonhomogeneous problems. The Third Edition is or

  19. Nanometallic chemistry: deciphering nanoparticle catalysis from the perspective of organometallic chemistry and homogeneous catalysis. (United States)

    Yan, Ning; Yuan, Yuan; Dyson, Paul J


    Nanoparticle (NP) catalysis is traditionally viewed as a sub-section of heterogeneous catalysis. However, certain properties of NP catalysts, especially NPs dispersed in solvents, indicate that there could be benefits from viewing them from the perspective of homogeneous catalysis. By applying the fundamental approaches and concepts routinely used in homogeneous catalysis to NP catalysts it should be possible to rationally design new nanocatalysts with superior properties to those currently in use.

  20. Cosmic strings and baryon decay catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Gregory, R.; Perkins, W.B.; Davis, A.C.; Brandenberger, R.H. (Fermi National Accelerator Lab., Batavia, IL (USA); Cambridge Univ. (UK); Brown Univ., Providence, RI (USA). Dept. of Physics)


    Cosmic strings, like monopoles, can catalyze proton decay. For integer charged fermions, the cross section for catalysis is not amplified, unlike in the case of monopoles. We review the catalysis processes both in the free quark and skyrmion pictures and discuss the implications for baryogenesis. We present a computation of the cross section for monopole catalyzed skyrmion decay using classical physics. We also discuss some effects which can screen catalysis processes. 32 refs., 1 fig.

  1. Cooperative catalysis designing efficient catalysts for synthesis

    CERN Document Server

    Peters, René


    Written by experts in the field, this is a much-needed overview of the rapidly emerging field of cooperative catalysis. The authors focus on the design and development of novel high-performance catalysts for applications in organic synthesis (particularly asymmetric synthesis), covering a broad range of topics, from the latest progress in Lewis acid / Br?nsted base catalysis to e.g. metal-assisted organocatalysis, cooperative metal/enzyme catalysis, and cooperative catalysis in polymerization reactions and on solid surfaces. The chapters are classified according to the type of cooperating acti

  2. Solid acid catalysis from fundamentals to applications

    CERN Document Server

    Hattori, Hideshi


    IntroductionTypes of solid acid catalystsAdvantages of solid acid catalysts Historical overviews of solid acid catalystsFuture outlookSolid Acids CatalysisDefinition of acid and base -Brnsted acid and Lewis acid-Acid sites on surfacesAcid strengthRole of acid sites in catalysisBifunctional catalysisPore size effect on catalysis -shape selectivity-Characterization of Solid Acid Catalysts Indicator methodTemperature programmed desorption (TPD) of ammoniaCalorimetry of adsorption of basic moleculesInfrare

  3. Jubilee session of the FIAN and IOFAN Research Councils marking 300 years since the beginning of physical science research in Russia and 80 years of FIAN (28 April 2014) (United States)


    A joint session of the Research Councils of the Lebedev Physical Institute of the Russian Academy of Sciences (FIAN) and the Prokhorov General Physics Institute of the Russian Academy of Sciences (IOFAN) marking 300 years since the beginning of physical science research in Russia and 80 years of FIAN was held on 28 April 2014 at the conference hall of the Lebedev Physical Institute, Russian Academy of Sciences (RAS).The agenda of the session, announced on the website of the Lebedev Physical Institute listed the following reports: Jubilee session (1) Fortov V E, President of the Russian Academy of Sciences, "300 years of physical research in Russia"; (2) Mesyats G A, Director of the Lebedev Physical Institute, RAS, "LPI: past and present"; (3) Shcherbakov I A, Director of the Prokhorov General Physics Institute, RAS, "History of the development of lasers"; (4) Baturin Yu M, Director of the Vavilov Institute for the History of Science and Technology, "'Kunstkamera' and the development of physics in the 18th-20th centuries". Scientific session (5) Kardashev N S (Astro-Cosmic Center, Lebedev Physical Institute, RAS) "Modern cosmic radio astronomy: results and prospects"; (6) Kochiev D G, Shcherbakov I A (Prokhorov General Physics Institute, RAS) "Lasers in medicine"; (7) Kolachevsky N N (Lebedev Physical Institute, RAS) "Precision laser spectroscopy in fundamental studies"; (8) Kryukov P G (Lebedev Physical Institute, RAS) "Powerful femtosecond lasers"; (9) Pudalov V M (Lebedev Physical Institute, RAS) "New high-temperature superconductors: research and prospects"; (10) Demikhov E I (Lebedev Physical Institute, RAS) "Magnetic resonance imaging". Videos of the reports are posted on the website of the Lebedev Physical Institute. • Precision laser spectroscopy in fundamental studies, N N Kolachevsky, K Yu Khabarova Physics-Uspekhi, 2014, Volume 57, Number 12, Pages 1230-1238

  4. Enantioselective Bronsted Acid Catalysis with Chiral Pentacarboxycyclopentadienes (United States)

    Gheewala, Chirag

    This thesis details the design and development of pentacarboxycyclopentadienes (PCCPs) as a new platform for enantioselective Bronsted acid catalysis. Prior to this research, enantioselective Bronsted acid catalysis was limited to the BINOL (and variations thereof) framework. While this catalyst platform has paved the way for a myriad of novel asymmetric chemical transformations, the utility of this catalyst scaffold has suffered from its lengthy and expensive preparations. As an alternative, starting from readily available 1,2,3,4,5-pentacarbomethoxycyclopentadiene and various chiral alcohols and amines, the synthesis of a library of strongly acidic chiral catalysts is described. The utility of these novel acid catalysts is explored in various transformations. As a prelude to the heart of this work, Chapter 1 focuses on the advancements made in asymmetric Bronsted acid catalysis through BINOL-phosphate derived catalysts, focusing on the major accomplishments made by researchers since 2004. The provided review highlights the utility of these chiral acid catalysts but also reveals the need for a new scaffold that is more affordable and accessible. Chapter 2 discusses the background of PCCPs, including its initial discovery and subsequent applications. Our work in developing novel transesterified and amidated derivatives is discussed with accompanying crystal structures of achiral and chiral PCCPs. pKa measurements demonstrate the capacity of PCCPs to be used as strong Bronsted acid catalysts and are compared to literature values of known Bronsted acid catalysts. Chapter 3 focuses on the utility of PCCPs as enantioselective Bronsted acid catalysts in a variety of chemical transformations including the Mukaiyama-Mannich reaction, transfer hydrogenation, Pictet-Spengler reaction, diaryl alcohol substitution, Mukayaiama oxocarbenium aldol reaction, and [4+2]-cycloaddition. Catalyst loadings down to 0.01 mol% and reaction scale up to 25 grams in the Mukaiyama

  5. Thirty years of microbial P450 monooxygenase research: Peroxo-heme intermediates-The central bus station in heme oxygenase catalysis

    International Nuclear Information System (INIS)

    Oxygen has always been recognized as an essential element of many life forms, initially through its role as a terminal electron acceptor for the energy-generating pathways of oxidative phosphorylation. In 1955, Hayaishi et al. [Mechanism of the pyrocatechase reaction, J. Am. Chem. Soc. 77 (1955) 5450-5451] presented the most important discovery that changed this simplistic view of how Nature uses atmospheric dioxygen. His discovery, the naming and mechanistic understanding of the first 'oxygenase' enzyme, has provided a wonderful opportunity and scientific impetus for four decades of researchers. This volume provides an opportunity to recognize the breakthroughs of the 'Hayaishi School.' Notable have been the prolific contributions of Professor Ishimura et al. [Oxygen and life. Oxygenases, Oxidases and Lipid Mediators, International Congress Series, Elsevier, Amsterdam, 2002], a first-generation Hayaishi product, to characterization of the cytochrome P450 monooxygenases

  6. Beginning Android 3

    CERN Document Server

    Murphy, Mark


    The vibrant and rich Android development platform, created by Google and the Open Handset Alliance, continues to be a platform in its truest sense, encompassing hundreds of classes beyond the traditional Java classes and open source components that ship with the software development kit. Android's continued growth includes support for Flash and Flash gaming apps, Wi-Fi tethering, improved performance, WebM or WebMedia integration for HTML5-based video and other multimedia APIs, Chrome OS (WebOS) integration, and more. With Beginning Android 3, you'll learn how to develop applications for Andro

  7. Begining Java EE 7

    CERN Document Server

    Gonclaves, Antonio


    Java Enterprise Edition (Java EE) continues to be one of the leading Java technologies and platforms. Beginning Java EE 7 is the first tutorial book on Java EE 7. Step by step and easy to follow, this book describes many of the Java EE 7 specifications and reference implementations, and shows them in action using practical examples. This definitive book also uses the newest version of GlassFish to deploy and administer the code examples. Written by an expert member of the Java EE specification request and review board in the Java Community Process (JCP), this book contains the best information possible, from an expert’s perspective on enterprise Java technologies.

  8. Cinder begin creative coding

    CERN Document Server

    Rijnieks, Krisjanis


    Presented in an easy to follow, tutorial-style format, this book will lead you step-by-step through the multi-faceted uses of Cinder.""Cinder: Begin Creative Coding"" is for people who already have experience in programming. It can serve as a transition from a previous background in Processing, Java in general, JavaScript, openFrameworks, C++ in general or ActionScript to the framework covered in this book, namely Cinder. If you like quick and easy to follow tutorials that will let yousee progress in less than an hour - this book is for you. If you are searching for a book that will explain al

  9. Beginning Swift programming

    CERN Document Server

    Lee, Wei-Meng


    Enter the Swift future of iOS and OS X programming Beginning Swift Programming is your ideal starting point for creating Mac, iPhone, and iPad apps using Apple's new Swift programming language. Written by an experienced Apple developer and trainer, this comprehensive guide explains everything you need to know to jumpstart the creation of your app idea. Coverage includes data types, strings and characters, operators and functions, arrays and dictionaries, control flow, and looping, with expert guidance on classes, objects, class inheritance, closures, protocols, and generics. This succinct - ye

  10. Beginning software engineering

    CERN Document Server

    Stephens, Rod


    Beginning Software Engineering demystifies the software engineering methodologies and techniques that professional developers use to design and build robust, efficient, and consistently reliable software. Free of jargon and assuming no previous programming, development, or management experience, this accessible guide explains important concepts and techniques that can be applied to any programming language. Each chapter ends with exercises that let you test your understanding and help you elaborate on the chapter's main concepts. Everything you need to understand waterfall, Sashimi, agile, RAD, Scrum, Kanban, Extreme Programming, and many other development models is inside!

  11. Cosmology without a beginning

    CERN Multimedia

    CERN. Geneva


    Most of the puzzles with standard big bang cosmology can be avoided if the big bang is NOT identified with the beginning of time. The short-distance cutoff and duality symmetries of superstring theory suggest a new (so-called pre-big bang) cosmology in which the birth of our Universe is the result of a long classical evolution characterized by a gravitational instability. I will motivate and describe this heretical scenario and compare its phenomenological implications with those of ortodox (post-big bang) inflation.

  12. Beginning Android 2

    CERN Document Server

    Murphy, Mark


    The Android development platform, created by Google and the Open Handset Alliance, is a platform in its truest sense, encompassing hundreds of classes beyond the traditional Java classes and open source components that ship with the SDK. With Beginning Android 2, you'll learn how to develop applications for Android 2.x mobile devices, using simple examples that are ready to run with your copy of the SDK. Author, Android columnist, writer, developer, and community advocate Mark L. Murphy will show you what you need to know to get started programming Android applications, including how to craft

  13. Beginning Windows 8

    CERN Document Server

    Halsey, Mike


    Windows 8 has been described by Microsoft as its 'boldest' Windows release ever. Beginning Windows 8 takes you through the new features and helps you get more out of the familiar to reveal the possibilities for this amazing new operating system. You will learn, with non-technical language used throughout, how to get up and running in the new Windows interface, minimize downtime, maximize productivity, and harness the features you never knew existed to take control of your computer and enjoy the peace of mind and excitement that comes with it. From tips and tweaks to easy-to-follow guides and d

  14. Beginning partial differential equations

    CERN Document Server

    O'Neil, Peter V


    A rigorous, yet accessible, introduction to partial differential equations-updated in a valuable new edition Beginning Partial Differential Equations, Second Edition provides a comprehensive introduction to partial differential equations (PDEs) with a special focus on the significance of characteristics, solutions by Fourier series, integrals and transforms, properties and physical interpretations of solutions, and a transition to the modern function space approach to PDEs. With its breadth of coverage, this new edition continues to present a broad introduction to the field, while also addres

  15. Beginning programming for dummies

    CERN Document Server

    Wang, Wallace


    Do you think the programmers who work at your office are magical wizards who hold special powers that manipulate your computer? Believe it or not, anyone can learn how to write programs, and it doesn't take a higher math and science education to start. Beginning Programming for Dummies shows you how computer programming works without all the technical details or hard programming language. It explores the common parts of every computer programming language and how to write for multiple platforms like Windows, Mac OS X, or Linux. This easily accessible guide provides you with the tools

  16. An expedient variant of Heck Reaction of alkenyl nonaflates: Homogeneous ligand-free palladium catalysis at room temperature

    Czech Academy of Sciences Publication Activity Database

    Vogel, M. A. K.; Stark, Ch. B.; Lyapkalo, Ilya


    Roč. 349, č. 7 (2007), s. 1019-1024 ISSN 1615-4150 Institutional research plan: CEZ:AV0Z40550506 Keywords : alkenyl nonaflates * catalyst poisoning * Heck reaction * homogeneous catalysis * ligand-free catalysis Subject RIV: CC - Organic Chemistry Impact factor: 4.977, year: 2007

  17. The Beginning of Protohaykian Calendar (United States)

    Broutian, G. H.


    From its foundation, studies in the field of history of Armenian astronomy and Armenian calendars were integral to astrophysical researches of the Byurakan Observatory. It is important to note the monographs and articles of H. Badalian and B. Toumanian in this field. As the result of our work in this field, beginning of the Haykian calendar (BC 2341) and the concept of Protohaykian calendar were established. In the present work an attempt is made to determine the beginning of the oldest Armenian calendar-the Protohaykian calendar. It is shown that Protohaykian calendar was originated when the heliacal rising of the star Spica (α Virgo) was observable from Armenia 8 days before summer solstice. Calculations made on this basis provide date of the beginning of this calendar as BC 9000 with an error not to exceed 80 years. This date is in correspondence with the date of observations of the Pleiades from Metsamor (about BC 9000), that was found a few years ago. Meanwhile, it also corresponds to the geological data, which prove, that the oldest lake (Araratian Sea) in the territory of modern Araratian valley was dried out at the same time. There is also good correlation with the time of cultivation of crops that was done in the territory of historical Armenia about 12000 years ago.

  18. Homogeneous catalysis by transition metals

    International Nuclear Information System (INIS)

    Masters, K.


    Fundamentals of homogeneous catalysis by metal complex aAe presented in the monograph along with the mechanisms of practically all types of catalytic reactions proceeding in the presence of transition metal complexes. In particular, considered are: catalytic cycles for olefin hydrogenation in the presence of Ru(2) complex; for alkene epoxidation catalyzed by Mo(6); for alkene metathesis reaction catalyzed by Ta and W compounds. Catalytic systems on the basis of Zr, Mo, W, Ru complexes being in the stage of development of the processes of nitrogen fixation reductive oligomerization alkene activation are described. Bibliography contains more than 400 references

  19. Fundamental concepts in heterogeneous catalysis

    CERN Document Server

    Norskov, Jens K; Abild-Pedersen, Frank; Bligaard, Thomas


    This book is based on a graduate course and suitable as a primer for any newcomer to the field, this book is a detailed introduction to the experimental and computational methods that are used to study how solid surfaces act as catalysts.   Features include:First comprehensive description of modern theory of heterogeneous catalysisBasis for understanding and designing experiments in the field   Allows reader to understand catalyst design principlesIntroduction to important elements of energy transformation technologyTest driven at Stanford University over several semesters

  20. Contrast and Synergy between Electrocatalysis and Heterogeneous Catalysis

    Directory of Open Access Journals (Sweden)

    Andrzej Wieckowski


    Full Text Available The advances in spectroscopy and theory that have occurred over the past two decades begin to provide detailed in situ resolution of the molecular transformations that occur at both gas/metal as well as aqueous/metal interfaces. These advances begin to allow for a more direct comparison of heterogeneous catalysis and electrocatalysis. Such comparisons become important, as many of the current energy conversion strategies involve catalytic and electrocatalytic processes that occur at fluid/solid interfaces and display very similar characteristics. Herein, we compare and contrast a few different catalytic and electrocatalytic systems to elucidate the principles that cross-cut both areas and establish characteristic differences between the two with the hope of advancing both areas.

  1. Homogeneous and heterogeneous catalysis production and ...

    African Journals Online (AJOL)

    While the homogeneous catalysis route produced higher biodiesel yields, the heterogeneous catalyst method produced biodiesel of lower ester content. The fuel properties of biodiesels and blends were analysed quantitati-vely, and the biodiesel produced by homogeneous catalysis compared favourably with conventional ...

  2. catalysis of chemical processes: particular teaching aspects

    African Journals Online (AJOL)


    of catalysis is included in the majority of textbooks covering, in particular, general chemistry, industrial processes and technologies, biochemistry and biotechnology[7-16]. Catalysis understood as an acceleration of a chemical reaction in approaching the equilibrium state is extremely important at the stage of obtaining the ...

  3. The evolution of regulatory framework of informatization of universities research libraries in Ukraine in the end of XX – the beginning of XXI century

    Directory of Open Access Journals (Sweden)

    R. Y. Rizhniak


    Full Text Available The article examines the history of Regulatory and Statutory Support of information research libraries of higher school in our country during a period ranging from 80’s of the twentieth century to the present. The following task were resolved to achieve the research objective: there were clarified source base and historiography of the research, defined basic facts of Regulatory and Statutory Support of informatization of the research libraries of universities in Ukraine at a certain historical period, defined the basic stages of the legal maintenance of informatization of the research libraries in higher educational institutions of Ukraine during the specified period. In the historical sequence of acceptance and introduction, there are analyzed main provisions of state regulations that were intended to regulate the basic laws of research libraries of higher educational establishments in Ukraine. The basic steps of creating a legal framework of libraries of higher school: at the first stage (late 80’s to late 90-s of XX century there were adopted regulations on solving strategic problems of informatization of Ukrainian society, which became a prerequisite for the development of informatization of Ukrainian libraries; at the second phase (started in the late 90-s of XX century were developed legal principles and standards of informatization of research of libraries.

  4. Researching Our Own Practice: An Individual Creative Process and a Dialogic-Collaborative Process: Self Knowledge is the Beginning of Wisdom. Krishnamurti (1991, p. 196

    Directory of Open Access Journals (Sweden)

    Farren Margaret


    Full Text Available In this paper, we explain how our individual PhD enquiries (Farren, 2006; Crotty, 2012 have informed the philosophical underpinnings of our postgraduate programmes. The approach used to ensure validity and rigour in the research process is presented. We report on the development of the International Research Centre for e-Innovation and Workplace Learning and its collaboration in European projects such as Pathway to Inquiry Based Learning, Inspiring Science Education (ISE and the African based Global e-Schools and Communities Initiative (GeSCI project Leadership Development in ICT and the Knowledge Society. Our claim is that researching our own practice can be a transformative experience for the practitioner-researcher who is committed to generating knowledge that has personal, professional and social value.

  5. "Nanocrystal bilayer for tandem catalysis"

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong


    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

  6. Chemistry of Fluorinated Carbon Acids: Synthesis, Physicochemical Properties, and Catalysis. (United States)

    Yanai, Hikaru


    The bis[(trifluoromethyl)sulfonyl]methyl (Tf2CH; Tf=SO2CF3) group is known to be one of the strongest carbon acid functionalities. The acidity of such carbon acids in the gas phase is stronger than that of sulfuric acid. Our recent investigations have demonstrated that this type of carbon acids work as novel acid catalysts. In this paper, recent achievements in carbon acid chemistry by our research group, including synthesis, physicochemical properties, and catalysis, are summarized.

  7. "In Dreams Begins Responsibility": A Self-Study about How Insights from Dreams May Be Brought into the Sphere of Action Research (United States)

    Balogh, Ruth


    This paper argues that material from dreams offers a resource within the social sphere that has potential for the practice of action research. The modern approach to dream interpretation, following Freud, has almost exclusively been situated at the level of the therapeutic dyad where the significance of dream material is circumscribed within…

  8. Molecular-Level Design of Heterogeneous Chiral Catalysis

    International Nuclear Information System (INIS)

    Zaera, Francisco


    The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration

  9. Molecular-Level Design of Heterogeneous Chiral Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Zaera


    The following is a proposal to continue our multi-institutional research on heterogeneous chiral catalysis. Our team combines the use of surface-sensitive analytical techniques for the characterization of model systems with quantum and statistical mechanical calculations to interpret experimental data and guide the design of future research. Our investigation focuses on the interrelation among the three main mechanisms by which enantioselectivity can be bestowed to heterogeneous catalysts, namely: (1) by templating chirality via the adsorption of chiral supramolecular assemblies, (2) by using chiral modifiers capable of forming chiral complexes with the reactant and force enantioselective surface reactions, and (3) by forming naturally chiral surfaces using imprinting chiral agents. Individually, the members of our team are leaders in these various aspects of chiral catalysis, but the present program provides the vehicle to generate and exploit the synergies necessary to address the problem in a comprehensive manner. Our initial work has advanced the methodology needed for these studies, including an enantioselective titration procedure to identify surface chiral sites, infrared spectroscopy in situ at the interface between gases or liquids and solids to mimic realistic catalytic conditions, and DFT and Monte Carlo algorithms to simulate and understand chirality on surfaces. The next step, to be funded by the monies requested in this proposal, is to apply those methods to specific problems in chiral catalysis, including the identification of the requirements for the formation of supramolecular surface structures with enantioselective behavior, the search for better molecules to probe the chiral nature of the modified surfaces, the exploration of the transition from supramolecular to one-to-one chiral modification, the correlation of the adsorption characteristics of one-to-one chiral modifiers with their physical properties, in particular with their configuration

  10. Educational anthropology as a major approach for educational research: The beginnings and the evolution of educational anthropology, with an overview of its introduction in the Greek educational context


    Ioannis Sideris


    This article is presenting and investigating the input of social and cultural anthropology in educational research. Moreover, the cultural focus is on Greece and Greek educational institutions. Socio-cultural anthropology offers a multiplicity of alternative pathways to the investigation of ‘who we are’ and why we behave the way we do through the study of cultures and institutions different from ours. The anthropology of education investigates a number of problems such as the socialization fu...

  11. Nanocrystal assembly for tandem catalysis (United States)

    Yang, Peidong; Somorjai, Gabor; Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu


    The present invention provides a nanocrystal tandem catalyst comprising at least two metal-metal oxide interfaces for the catalysis of sequential reactions. One embodiment utilizes a nanocrystal bilayer structure formed by assembling sub-10 nm platinum and cerium oxide nanocube monolayers on a silica substrate. The two distinct metal-metal oxide interfaces, CeO.sub.2--Pt and Pt--SiO.sub.2, can be used to catalyze two distinct sequential reactions. The CeO.sub.2--Pt interface catalyzed methanol decomposition to produce CO and H.sub.2, which were then subsequently used for ethylene hydroformylation catalyzed by the nearby Pt--SiO.sub.2 interface. Consequently, propanal was selectively produced on this nanocrystal bilayer tandem catalyst.

  12. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew


    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an


    Directory of Open Access Journals (Sweden)

    O. Voronkin


    Full Text Available The article presents the historical and pedagogical analysis of psychological and educational research of information and communication technologies from 1950 to the present time. The personal contribution of scientists in the study of ICT is described. Materials of periodicals and PhD theses are analyzed. Identified the following areas of dissertation researchs: a psychological and pedagogical basis of programmed instruction, study aids and automation of the educational process; b the use of automated (information systems and training classes to build interactive learning systems, didactic capabilities of your computer; c the problem of information culture (competence of students (teachers; d psychological, didactic, philosophical, methodological aspects of the organization of learning using ICT; e the development of information and educational environment and information and communication technology of training.nIn addition to educational, psychological and other aspects of the use of ICT, important role belongs to the technological aids to support lifelong learning. The possible versions for the implementation of the forms of training activities in ICT environment - lectures, seminars, consulting, laboratory classes and webinars are considered. The author concludes that the most effective forms of learning activity involves a level of mastery of the material in which the student will be able to teach others.

  14. Homogeneous Catalysis with Metal Complexes Fundamentals and Applications

    CERN Document Server

    Duca, Gheorghe


    The book about homogeneous catalysis with metal complexes deals with the description of the reductive-oxidative, metal complexes  in a liquid phase (in polar solvents, mainly in water, and less in nonpolar solvents). The exceptional importance of the redox processes in chemical systems, in the reactions occuring in living organisms, the environmental processes, atmosphere, water, soil, and in industrial technologies (especially in food-processing industries) is discussed. The detailed practical aspects of the established regularities are explained for solving the specific practical tasks in various fields of industrial chemistry, biochemistry, medicine, analytical chemistry and ecological chemistry. The main scope of the book is the survey and systematization of the latest advances in homogeneous catalysis with metal complexes. It gives an overview of the research results and practical experience accumulated by the author during the last decade.

  15. Answering the Questions of Beginning Teachers


    Harrington, Ingrid


    Research reports that despite new or beginning teachers being well received by the education profession, their first year experience is often traumatic and difficult nature. This is not a new phenomenon and is a problem shared by many new teachers nationwide and in the western world. Consequently, the retention rate for new teachers is decreasing at an alarming rate and is currently reported that 33% of beginning teachers in New South Wales do not expect to be teaching in public schools withi...

  16. Educational anthropology as a major approach for educational research: The beginnings and the evolution of educational anthropology, with an overview of its introduction in the Greek educational context

    Directory of Open Access Journals (Sweden)

    Ioannis Sideris


    Full Text Available This article is presenting and investigating the input of social and cultural anthropology in educational research. Moreover, the cultural focus is on Greece and Greek educational institutions. Socio-cultural anthropology offers a multiplicity of alternative pathways to the investigation of ‘who we are’ and why we behave the way we do through the study of cultures and institutions different from ours. The anthropology of education investigates a number of problems such as the socialization function of schooling, the transmission of culture from older to younger generation within the educational process, the role of ethnocentrism in the reproduction of inequalities and the possibilities of cultural relativism in schools. At the end of this presentation we review the emerging field of educational anthropology in Greece.

  17. Special section on Nano-Catalysis

    CSIR Research Space (South Africa)

    Makgwane, PR


    Full Text Available to achieve sustainable and green catalytic processes. The special issue contains 40 peer reviewed scientific papers that include four comprehensive review articles contributions from the invited experts in the respective catalysis fields....

  18. Organometallic catalysis: some contributions to organic synthesis

    Directory of Open Access Journals (Sweden)

    Elena V. Gusevskaya


    Full Text Available In the present paper some general aspects of metal complex catalysis and its applications for oxyfunctionalization of various olefins, including naturally occurring ones, via selective oxidation, hydroformylation and alkoxycarbonylation are discussed.

  19. Current trends of surface science and catalysis

    CERN Document Server

    Park, Jeong Young


    Including detail on applying surface science in renewable energy conversion, this book covers the latest results on model catalysts including single crystals, bridging "materials and pressure gaps", and hot electron flows in heterogeneous catalysis.

  20. Water Research Consortium U.S. Department of Energy Grant Award Number DE-FG02-05ER64132 Final Technical Report For Period Beginning: 15 September 2005 And Ending: 31 December 2009 Report Date: 16 March 2010

    Energy Technology Data Exchange (ETDEWEB)

    Steven R. Billingsley


    This report summarizes the activities of the INRA Water Research Consortium (IWRC) for the period beginning September 15, 2005 and ending December 16, 2010. This report compares accomplishments to project objectives, documents the activities associated with this project, and lists products developed during the course of the project. The Water Resources Research Needs Assessment team received funding from the Inland Northwest Research Alliance Water Resources Steering Committee to facilitate a structured needs assessment process that could provide a basis for future targeted research efforts to improve regional water resources management in the Inland Northwest region. The original INRA proposal specifically mentions the need to conduct a detailed assessment of the information and research needs of policy makers and water user groups during a period of increasing competition for scarce water supplies. A particular focus of this assessment would be to understand what types of research might facilitate water resource management during periods of drought. The specific goals of the Needs Assessment project were to: (1) Quickly ascertain the perceptions of diverse stakeholders in this region; (2) Condense this complex information into a format that can be shared with the INRA scientific panel, and (3) Develop of a realistic set of research needs & priorities that can shape future INRA-funded research activities.

  1. Recent advances in homogeneous nickel catalysis. (United States)

    Tasker, Sarah Z; Standley, Eric A; Jamison, Timothy F


    Tremendous advances have been made in nickel catalysis over the past decade. Several key properties of nickel, such as facile oxidative addition and ready access to multiple oxidation states, have allowed the development of a broad range of innovative reactions. In recent years, these properties have been increasingly understood and used to perform transformations long considered exceptionally challenging. Here we discuss some of the most recent and significant developments in homogeneous nickel catalysis, with an emphasis on both synthetic outcome and mechanism.

  2. Advancing Sustainable Catalysis with Magnetite Surface ... (United States)

    This article surveys the recent developments in the synthesis, surface modification, and synthetic applications of magnetitenanoparticles. The emergence of iron(II,III) oxide (triiron tetraoxide or magnetite; Fe3O4, or FeO•Fe2O3) nanoparticles as a sustainable support in heterogeneous catalysis is highlighted. Use of an oxide of earth-abundant iron for various applications in catalysis and environmental remediation.

  3. Enzyme catalysis with small ionic liquid quantities. (United States)

    Fischer, Fabian; Mutschler, Julien; Zufferey, Daniel


    Enzyme catalysis with minimal ionic liquid quantities improves reaction rates, stereoselectivity and enables solvent-free processing. In particular the widely used lipases combine well with many ionic liquids. Demonstrated applications are racemate separation, esterification and glycerolysis. Minimal solvent processing is also an alternative to sluggish solvent-free catalysis. The method allows simplified down-stream processing, as only traces of ionic liquids have to be removed.

  4. Listening begins at home. (United States)

    Stengel, James R; Dixon, Andrea L; Allen, Chris T


    Procter & Gamble has long been regarded as a major power of the marketing world and a prime training ground for marketers. But in the summer of 2000, with half of P&G's top 15 brands losing market share and employee morale in ruins, company executives realized that the marketing organization was in trouble. Training programs had been dramatically downsized and in some cases eliminated, employees were being fast-tracked up the career ladder without sufficient time to develop and hone their skills, mentoring had all but disappeared, and the marketing career path had lost its prestige. In an attempt to rebuild P&G's marketing strength, James Stengel, the heir apparent to the chief marketing officer position, began working with University of Cincinnati professors Chris Allen and Andrea Dixon on a new training program to fix the weaknesses in the marketing organization. But when the two professors began interviewing P&G senior executives, they discovered that the plans in motion for mapping out the marketing group's recovery were based not on data but on the intuition of a few individuals at corporate headquarters. So began the most comprehensive internal research endeavor in P&G marketing's history. Using the company's existing process for consumer research, Allen and Dixon shadowed employees, conducted one-on-one interviews, held focus-group sessions, and surveyed 3,500 members of the marketing staff to learn what the company was doing right--and wrong--and what mattered most to its people. The results led to the most sweeping redesign of P&G's marketing organization in 60 years. In this article, the authors explore the value of listening to employees--and truly hearing them. One of their conclusions: A structured research process can show you what's really on employees' minds.

  5. Mechanisms and Design in Homogeneous Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Clark R. Landis


    The major goal of this research is the determination of structure-activity relationships with respect to the elementary reactions that constitute catalytic alkene polymerization. Three classes of structure-activity relationships pertain to this work: (1) The influence of the nature of the propagating alkyl (secondary, primary, β-substituted) and alkene monomer on the rates and selectivity of propagation, termination, isomerization, hydrogenolysis, etc. Such analyses are possible by direct observation methods (2) Influence of Cp-ligand substituents on fundamental reaction steps by application of direct observation and quenched-flow methods (3) Influence of counterion and solvent polarity on rates and selectivities of elementary steps during polymerization. At this point our rate of progress is limited by a combination of inefficiencies in some data collection modes (particularly quenched-flow studies) and by a relatively narrow range of accessible rates (especially for the NMR methods). Therefore, the bulk of our work concerns the development NMR, mass spectrometric, and chromatographic methods for probing catalytic reactions in a high throughput mode. Although these methods will be applied in the context of alkene polymerization, the NMR and mass spectrometric methods are completely general and will benefit research in all areas of catalysis.

  6. The Beginnings of Airborne Weightlessness Research. (United States)


    in Mendoza. That was the Fiat G 55-B which was similar to the Messerschmitt 109, with which I was familiar . I4 b 1 4 I ... L - PS. NA DC-850 16-60 C...Vol- L.: Sulla fisiopatologia durante il volo ntee suoreths ofathesemissiwasfohotem- nello spazio. Rivista Medicina Acvo- unteered for this task, wl

  7. Specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions in aqueous media

    NARCIS (Netherlands)

    Mubofu, Egid B.; Engberts, Jan B.F.N.


    A comparative study of specific acid catalysis and Lewis acid catalysis of Diels–Alder reactions between dienophiles (1, 4 and 6) and cyclopentadiene (2) in water and mixed aqueous media is reported. The reactions were performed in water with copper(II) nitrate as the Lewis acid catalyst whereas

  8. Specific acid catalysis and Lewis acid catalysis of Diels-Alder reactions in aqueous media

    NARCIS (Netherlands)

    Mubofu, E.B.; Engberts, J.B.F.N.

    A comparative study of specific acid catalysis and Lewis acid catalysis of Diells-Alder reactions between dienophiles (1, 4 and 6) and cyclopentadiene (2) in water and mixed aqueous media is reported. The reactions were performed in water with copper(II) nitrate as the Lewis acid catalyst whereas


    Energy Technology Data Exchange (ETDEWEB)



    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  10. USD Catalysis Group for Alternative Energy - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hoefelmeyer, James


    I. Project Summary Catalytic processes are a major technological underpinning of modern society, and are essential to the energy sector in the processing of chemical fuels from natural resources, fine chemicals synthesis, and energy conversion. Advances in catalyst technology are enormously valuable since these lead to reduced chemical waste, reduced energy loss, and reduced costs. New energy technologies, which are critical to future economic growth, are also heavily reliant on catalysts, including fuel cells and photo-electrochemical cells. Currently, the state of South Dakota is underdeveloped in terms of research infrastructure related to catalysis. If South Dakota intends to participate in significant economic growth opportunities that result from advances in catalyst technology, then this area of research needs to be made a high priority for investment. To this end, a focused research effort is proposed in which investigators from The University of South Dakota (USD) and The South Dakota School of Mines and Technology (SDSMT) will contribute to form the South Dakota Catalysis Group (SDCG). The multidisciplinary team of the (SDCG) include: (USD) Dan Engebretson, James Hoefelmeyer, Ranjit Koodali, and Grigoriy Sereda; (SDSMT) Phil Scott Ahrenkiel, Hao Fong, Jan Puszynski, Rajesh Shende, and Jacek Swiatkiewicz. The group is well suited to engage in a collaborative project due to the resources available within the existing programs. Activities within the SDCG will be monitored through an external committee consisting of three distinguished professors in chemistry. The committee will provide expert advice and recommendations to the SDCG. Advisory meetings in which committee members interact with South Dakota investigators will be accompanied by individual oral and poster presentations in a materials and catalysis symposium. The symposium will attract prominent scientists, and will enhance the visibility of research in the state of South Dakota. The SDCG requests

  11. Catalysis-by-design impacts assessment

    Energy Technology Data Exchange (ETDEWEB)

    Fassbender, L L; Young, J K [Pacific Northwest Lab., Richland, WA (USA); Sen, R K [Sen (R.K.) and Associates, Washington, DC (USA)


    Catalyst researchers have always recognized the need to develop a detailed understanding of the mechanisms of catalytic processes, and have hoped that it would lead to developing a theoretical predictive base to guide the search for new catalysts. This understanding allows one to develop a set of hierarchical models, from fundamental atomic-level ab-initio models to detailed engineering simulations of reactor systems, to direct the search for optimized, efficient catalyst systems. During the last two decades, the explosions of advanced surface analysis techniques have helped considerably to develop the building blocks for understanding various catalytic reactions. An effort to couple these theoretical and experimental advances to develop a set of hierarchical models to predict the nature of catalytic materials is a program entitled Catalysis-by-Design (CRD).'' In assessing the potential impacts of CBD on US industry, the key point to remember is that the value of the program lies in developing a novel methodology to search for new catalyst systems. Industrial researchers can then use this methodology to develop proprietary catalysts. Most companies involved in catalyst R D have two types of ongoing projects. The first type, what we call market-driven R D,'' are projects that support and improve upon a company's existing product lines. Project of the second type, technology-driven R D,'' are longer term, involve the development of totally new catalysts, and are initiated through scientists' research ideas. The CBD approach will impact both types of projects. However, this analysis indicates that the near-term impacts will be on market-driven'' projects. The conclusions and recommendations presented in this report were obtained by the authors through personal interviews with individuals involved in a variety of industrial catalyst development programs and through the three CBD workshops held in the summer of 1989. 34 refs., 7 figs., 7 tabs.

  12. Photoredox catalysis by [Ru(bpy)3]2+ to trigger transformations of organic molecules. Organic synthesis using visible-light photocatalysis and its 20th century roots

    Czech Academy of Sciences Publication Activity Database

    Teplý, Filip


    Roč. 76, č. 7 (2011), s. 859-917 ISSN 0010-0765 R&D Projects: GA ČR GAP207/10/2391 Institutional research plan: CEZ:AV0Z40550506 Keywords : Ruthenium complexes * catalysis with dyes * visible light photoredox catalysis * photocatalysis * review Subject RIV: CC - Organic Chemistry Impact factor: 1.283, year: 2011

  13. Operando chemistry of catalyst surfaces during catalysis. (United States)

    Dou, Jian; Sun, Zaicheng; Opalade, Adedamola A; Wang, Nan; Fu, Wensheng; Tao, Franklin Feng


    Chemistry of a catalyst surface during catalysis is crucial for a fundamental understanding of mechanism of a catalytic reaction performed on the catalyst in the gas or liquid phase. Due to the pressure- or molecular density-dependent entropy contribution of gas or liquid phase of the reactants and the potential formation of a catalyst surface during catalysis different from that observed in an ex situ condition, the characterization of the surface of a catalyst under reaction conditions and during catalysis can be significant and even necessary for understanding the catalytic mechanism at a molecular level. Electron-based analytical techniques are challenging for studying catalyst nanoparticles in the gas or liquid phase although they are necessary techniques to employ. Instrumentation and further development of these electron-based techniques have now made in situ/operando studies of catalysts possible. New insights into the chemistry and structure of catalyst nanoparticles have been uncovered over the last decades. Herein, the origin of the differences between ex situ and in situ/operando studies of catalysts, and the technical challenges faced as well as the corresponding instrumentation and innovations utilized for characterizing catalysts under reaction conditions and during catalysis, are discussed. The restructuring of catalyst surfaces driven by the pressure of reactant(s) around a catalyst, restructuring in reactant(s) driven by reaction temperature and restructuring during catalysis are also reviewed herein. The remaining challenges and possible solutions are briefly discussed.

  14. Beginnings

    DEFF Research Database (Denmark)

    Rehfeld, Jens F


    The gut is the largest endocrine organ in the body. Gut hormones share some characteristics: Their structure groups hormones into families, each of which originate from a single gene. A hormone gene is often expressed in multiple peptides due to tandem genes, alternative splicing or differentiated...

  15. Beginning Teachers' Responses to Education Reform Agendas (United States)

    Adoniou, Misty


    National education reform agendas are increasingly prevalent in school systems around the world. Whilst we have a substantial body of research exploring the ways in which schools manage change agendas, there is less discussion of the impacts these agendas may have on beginning teachers and their retention in the profession. Here I report on a…

  16. Mozart Effect: Sound Beginnings? Infants and Toddlers. (United States)

    Caulfield, Rick


    Notes that outcomes of the "Mozart Effect" on early brain development are not thoroughly proven and presents challenges for future research. Points out that it is still unknown at what age exposure to musical concepts should begin, and that parents should allow children to pursue musical interests at their own pace to avoid burnout at a…

  17. Progress towards bioorthogonal catalysis with organometallic compounds. (United States)

    Völker, Timo; Dempwolff, Felix; Graumann, Peter L; Meggers, Eric


    The catalysis of bioorthogonal transformations inside living organisms is a formidable challenge--yet bears great potential for future applications in chemical biology and medicinal chemistry. We herein disclose highly active organometallic ruthenium complexes for bioorthogonal catalysis under biologically relevant conditions and inside living cells. The catalysts uncage allyl carbamate protected amines with unprecedented high turnover numbers of up to 270 cycles in the presence of water, air, and millimolar concentrations of thiols. By live-cell imaging of HeLa cells and with the aid of a caged fluorescent probe we could reveal a rapid development of intense fluorescence within the cellular cytoplasm and therefore support the proposed bioorthogonality of the catalysts. In addition, to illustrate the manifold applications of bioorthogonal catalysis, we developed a method for catalytic in-cell activation of a caged anticancer drug, which efficiently induced apoptosis in HeLa cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Sustainable green catalysis by supported metal nanoparticles. (United States)

    Fukuoka, Atsushi; Dhepe, Paresh L


    The recent progress of sustainable green catalysis by supported metal nanoparticles is described. The template synthesis of metal nanoparticles in ordered porous materials is studied for the rational design of heterogeneous catalysts capable of high activity and selectivity. The application of these materials in green catalytic processes results in a unique activity and selectivity arising from the concerted effect of metal nanoparticles and supports. The high catalytic performances of Pt nanoparticles in mesoporous silica is reported. Supported metal catalysts have also been applied to biomass conversion by heterogeneous catalysis. Additionally, the degradation of cellulose by supported metal catalysts, in which bifunctional catalysis of acid and metal plays the key role for the hydrolysis and reduction of cellulose, is also reported. Copyright 2009 The Japan Chemical Journal Forum and Wiley Periodicals, Inc.

  19. Competing role of catalysis-coagulation and catalysis-fragmentation in kinetic aggregation behaviours

    International Nuclear Information System (INIS)

    Li Xiao-Dong; Lin Zhen-Quan; Song Mei-Xia; Ke Jian-Hong


    We propose a kinetic aggregation model where species A aggregates evolve by the catalysis-coagulation and the catalysis-fragmentation, while the catalyst aggregates of the same species B or C perform self-coagulation processes. By means of the generalized Smoluchowski rate equation based on the mean-field assumption, we study the kinetic behaviours of the system with the catalysis-coagulation rate kernel K(i,j;l) ∝ l ν and the catalysis-fragmentation rate kernel F(i,j;l) ∝ l μ , where l is the size of the catalyst aggregate, and ν and μ are two parameters reflecting the dependence of the catalysis reaction on the size of the catalyst aggregate. The relation between the values of parameters ν and μ reflects the competing roles between the two catalysis processes in the kinetic evolution of species A. It is found that the competing roles of the catalysis-coagulation and catalysis-fragmentation in the kinetic aggregation behaviours are not determined simply by the relation between the two parameters ν and μ, but also depend on the values of these two parameters. When ν > μ and ν ≥ 0, the kinetic evolution of species A is dominated by the catalysis-coagulation and its aggregate size distribution a k (t) obeys the conventional or generalized scaling law; when ν k (t) approaches the scale-free form; and in other cases, a balance is established between the two competing processes at large times and a k (t) obeys a modified scaling law. (cross-disciplinary physics and related areas of science and technology)

  20. Request for Symposia Support: Advances in Olefin Polymerization Catalysis (United States)


    included, but were not limited to, heterogeneous catalysis , homogeneous catalysis , advances in catalyst activation, methods for polymer topological...SECURITY CLASSIFICATION OF: This Advances in Olefin Polymerization Catalysis symposium was held at the 247th ACS National Meeting and Exposition...March 19, 2014 in Dallas, Texas and consisted of twelve (12) invited/contributed talks. The hosting ACS division was the Division of Catalysis Science

  1. Plasma Chemistry and Catalysis in Gases and Liquids

    CERN Document Server

    Parvulescu, Vasile I; Lukes, Petr


    Filling the gap for a book that not only covers gases but also plasma methods in liquids, this is all set to become the standard reference on the topic. It considers the central aspects in plasma chemistry and plasma catalysis by focusing on the green and environmental applications, while also taking into account their practical and economic viability. With the topics addressed by an international group of major experts, this is a must-have for researchers, PhD students and postdocs specializing in the field.

  2. Charge Transfer and Catalysis at the Metal Support Interface

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Lawrence Robert [Univ. of California, Berkeley, CA (United States)


    Kinetic, electronic, and spectroscopic characterization of model Pt–support systems are used to demonstrate the relationship between charge transfer and catalytic activity and selectivity. The results show that charge flow controls the activity and selectivity of supported metal catalysts. This dissertation builds on extensive existing knowledge of metal–support interactions in heterogeneous catalysis. The results show the prominent role of charge transfer at catalytic interfaces to determine catalytic activity and selectivity. Further, this research demonstrates the possibility of selectively driving catalytic chemistry by controlling charge flow and presents solid-state devices and doped supports as novel methods for obtaining electronic control over catalytic reaction kinetics.

  3. Reflective Methodology: The Beginning Teacher (United States)

    Templeton, Ronald K.; Siefert, Thomas E.


    Offers a variety of specific techniques which will help the beginning teacher to implement reflective methodology and create an inquiry-centered classroom atmosphere, at the same time meeting the many more pressing demands of first-year teaching. (JES)

  4. Keynotes in energy-related catalysis

    CERN Document Server

    Kaliaguine, S


    Catalysis by solid acids, which includes (modified) zeolites, is of special relevance to energy applications. Acid catalysis is highly important in modern petroleum refining operations - large-scale processes such as fluid catalytic cracking, catalytic reforming, alkylation and olefin oligomerization rely on the transformation of hydrocarbons by acid catalysts. (Modified) zeolites are therefore essential for the improvement of existing processes and for technical innovations in the conversion of crude. There can be little doubt that zeolite-based catalysts will play a major role in the futu

  5. Heterogeneous catalysis at nanoscale for energy applications

    CERN Document Server

    Tao, Franklin (Feng); Kamat, Prashant V


    This book presents both the fundamentals concepts and latest achievements of a field that is growing in importance since it represents a possible solution for global energy problems.  It focuses on an atomic-level understanding of heterogeneous catalysis involved in important energy conversion processes. It presents a concise picture for the entire area of heterogeneous catalysis with vision at the atomic- and nano- scales, from synthesis, ex-situ and in-situ characterization, catalytic activity and selectivity, to mechanistic understanding based on experimental exploration and theoretical si

  6. Catalysis by nonmetals rules for catalyst selection

    CERN Document Server

    Krylov, Oleg V


    Catalysis by Non-metals: Rules of Catalyst Selection presents the development of scientific principles for the collection of catalysts. It discusses the investigation of the mechanism of chemosorption and catalysis. It addresses a series of properties of solid with catalytic activity. Some of the topics covered in the book are the properties of a solid and catalytic activity in oxidation-reduction reactions; the difference of electronegativities and the effective charges of atoms; the role of d-electrons in the catalytic properties of a solid; the color of solids; and proton-acid and proton-ba

  7. Direct sp(3)C-H acroleination of N-aryl-tetrahydroisoquinolines by merging photoredox catalysis with nucleophilic catalysis. (United States)

    Feng, Zhu-Jia; Xuan, Jun; Xia, Xu-Dong; Ding, Wei; Guo, Wei; Chen, Jia-Rong; Zou, You-Quan; Lu, Liang-Qiu; Xiao, Wen-Jing


    Sequence catalysis merging photoredox catalysis (PC) and nucleophilic catalysis (NC) has been realized for the direct sp(3) C-H acroleination of N-aryl-tetrahydroisoquinoline (THIQ). The reaction was performed under very mild conditions and afforded products in 50-91% yields. A catalytic asymmetric variant was proved to be successful with moderate enantioselectivities (up to 83 : 17 er).

  8. Transition metal catalysis in confined spaces

    NARCIS (Netherlands)

    Leenders, S.H.A.M.


    Chemical reactions are required for the conversion of feedstocks to valuable materials, such as different types of plastics, pharmaceutical ingredients and advanced materials. In order to facilitate the conversion of these feedstocks to a wide array of products, catalysis plays a prominent role.

  9. Homogeneous Catalysis by Transition Metal Compounds. (United States)

    Mawby, Roger


    Examines four processes involving homogeneous catalysis which highlight the contrast between the simplicity of the overall reaction and the complexity of the catalytic cycle. Describes how catalysts provide circuitous routes in which all energy barriers are relatively low rather than lowering the activation energy for a single step reaction.…

  10. Supported ionic liquid-phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Wasserscheid, P.


    The concept of supported ionic liquid-phase (SILP) catalysis has been demonstrated for gas- and liquid-phase continuous fixed-bed reactions using rhodium phosphine catalyzed hydroformylation of propene and 1-octene as examples. The nature of the support had important influence on both the catalytic...

  11. Confined catalysis under two-dimensional materials (United States)

    Li, Haobo; Xiao, Jianping; Bao, Xinhe


    Confined microenvironments formed in heterogeneous catalysts have recently been recognized as equally important as catalytically active sites. Understanding the fundamentals of confined catalysis has become an important topic in heterogeneous catalysis. Well-defined 2D space between a catalyst surface and a 2D material overlayer provides an ideal microenvironment to explore the confined catalysis experimentally and theoretically. Using density functional theory calculations, we reveal that adsorption of atoms and molecules on a Pt(111) surface always has been weakened under monolayer graphene, which is attributed to the geometric constraint and confinement field in the 2D space between the graphene overlayer and the Pt(111) surface. A similar result has been found on Pt(110) and Pt(100) surfaces covered with graphene. The microenvironment created by coating a catalyst surface with 2D material overlayer can be used to modulate surface reactivity, which has been illustrated by optimizing oxygen reduction reaction activity on Pt(111) covered by various 2D materials. We demonstrate a concept of confined catalysis under 2D cover based on a weak van der Waals interaction between 2D material overlayers and underlying catalyst surfaces. PMID:28533413

  12. Transition metal catalysis in confined spaces

    NARCIS (Netherlands)

    Leenders, S.H.A.M.; Gramage-Doria, R.; de Bruin, B.; Reek, J.N.H.


    Transition metal catalysis plays an important role in both industry and in academia where selectivity, activity and stability are crucial parameters to control. Next to changing the structure of the ligand, introducing a confined space as a second coordination sphere around a metal catalyst has

  13. Loop residues and catalysis in OMP synthase

    DEFF Research Database (Denmark)

    Wang, Gary P.; Hansen, Michael Riis; Grubmeyer, Charles


    (preceding paper in this issue, DOI 10.1021/bi300083p)]. The full expression of KIEs by H105A and E107A may result from a less secure closure of the catalytic loop. The lower level of expression of the KIE by K103A suggests that in these mutant proteins the major barrier to catalysis is successful closure...

  14. Surface temperature excess in heterogeneous catalysis

    NARCIS (Netherlands)

    Zhu, L.


    In this dissertation we study the surface temperature excess in heterogeneous catalysis. For heterogeneous reactions, such as gas-solid catalytic reactions, the reactions take place at the interfaces between the two phases: the gas and the solid catalyst. Large amount of reaction heats are released

  15. Hydrogen-bonding catalysis of sulfonium salts


    Kaneko, Shiho; Kumatabara, Yusuke; Shimizu, Shoichi; Maruoka, Keiji; Shirakawa, Seiji


    Although quaternary ammonium and phosphonium salts are known as important catalysts in phase-transfer catalysis, the catalytic ability of tertiary sulfonium salts has not yet been well demonstrated. Herein, we demonstrate the catalytic ability of trialkylsulfonium salts as hydrogen-bonding catalysts on the basis of the characteristic properties of the acidic α hydrogen atoms on alkylsulfonium salts.

  16. Catalysis and Multi-Component Reactions (United States)

    Shibasaki, Masakatsu; Yus, Miguel; Bremner, Stacy; Comer, Eamon; Shore, Gjergji; Morin, Sylvie; Organ, Michael G.; van der Eycken, Erik; Merkul, Eugen; Dorsch, Dieter; Müller, Thomas J. J.; Ryabukhin, Sergey V.; Ostapchuk, Eugeniy N.; Plaskon, Andrey S.; Volochnyuk, Dmitriy M.; Shivanyuk, Alexander N.; Tolmachev, Andrey A.; Sheibani, Hassan; Babaie, Maryam; Behzadi, Soheila; Dabiri, Minoo; Bahramnejad, Mahboobeh; Bashiribod, Sahareh; Hekmatshoar, Rahim; Sadjadi, Sodeh; Khorasani, Mohammad; Polyakov, Anatoliy I.; Eryomina, Vera A.; Medvedeva, Lidiya A.; Tihonova, Nadezhda I.; Listratova, Anna V.; Voskressensky, Leonid G.; Merkul, Eugen; Dorsch, Dieter; Müller, Thomas J. J.; Sheibani, Hassan; Esfandiarpoor, Zeinab; Behzadi, Soheila; Titova, Julia A.; Fedorova, Olga V.; Ovchinnikova, Irina G.; Valova, Marina S.; Koryakova, Olga V.; Rusinov, Gennady L.; Charushin, Valery N.; Hekmatshoar, Rahim; Sadjadi, Sodeh

    We have been studying the development of new asymmetric two-center catalysis using rare earth alkoxides and bifunctional sugar and related ligands. In The Fourth International Conference on Multi-Component Reactions and Related Chemistry (MCR 2009), new catalytic asymmetric reactions using catalysts 1 and 2 and catalytic asymmetric syntheses of ranirestat 3 and tamiflu 4 will be presented.

  17. The mechanism of montmorillonite catalysis in RNA synthesis (United States)

    Joshi, Prakash

    montmorillonite as reaction occurs. The application of the Scherer equation to the X-ray diffraction data showed differences in domain size. Modeling of the size of the activated nucleotide monomers and the charge on the montmorillonite surface provided an interpretation of how these factors influence adsorption. This research provides a basis for further understanding of the physical processes in the mechanism of this catalysis in prebiotic reactions. This research was supported by NASA Astrobiology Institute Grant NNA09DA80A. References: Aldersley, M.F., Joshi, P.C., Price, J.D., Ferris, J.P. The role of montmorillonite in its catalysis of RNA synthesis. Appl. Clay Sci. 54,1-14, 2011. Bishop, J.L., Dobrea, E.J.N., Mckeown, N.K., Parenta, M. Phyllos- ilicate diversity and past aqueous activity revealed at Mawrth Vallis, Mars. Science 321, 830-833, 2008. Joshi, P.C., Aldersley, M.F., Delano, J.W., Ferris, J.P., Mechanism of montmorillonite catalysis in the formation of RNA oligomers, J. Am. Chem. Soc., 131, 13369-13374, 2009.

  18. Center for Catalysis at Iowa State University

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, George A.


    The overall objective of this proposal is to enable Iowa State University to establish a Center that enjoys world-class stature and eventually enhances the economy through the transfer of innovation from the laboratory to the marketplace. The funds have been used to support experimental proposals from interdisciplinary research teams in areas related to catalysis and green chemistry. Specific focus areas included: • Catalytic conversion of renewable natural resources to industrial materials • Development of new catalysts for the oxidation or reduction of commodity chemicals • Use of enzymes and microorganisms in biocatalysis • Development of new, environmentally friendly reactions of industrial importance These focus areas intersect with barriers from the MYTP draft document. Specifically, section Processing and Conversion has a list of bulleted items under Improved Chemical Conversions that includes new hydrogenation catalysts, milder oxidation catalysts, new catalysts for dehydration and selective bond cleavage catalysts. Specifically, the four sections are: 1. Catalyst development (7.4.12.A) 2. Conversion of glycerol (7.4.12.B) 3. Conversion of biodiesel (7.4.12.C) 4. Glucose from starch (7.4.12.D) All funded projects are part of a soybean or corn biorefinery. Two funded projects that have made significant progress toward goals of the MYTP draft document are: Catalysts to convert feedstocks with high fatty acid content to biodiesel (Kraus, Lin, Verkade) and Conversion of Glycerol into 1,3-Propanediol (Lin, Kraus). Currently, biodiesel is prepared using homogeneous base catalysis. However, as producers look for feedstocks other than soybean oil, such as waste restaurant oils and rendered animal fats, they have observed a large amount of free fatty acids contained in the feedstocks. Free fatty acids cannot be converted into biodiesel using homogeneous base-mediated processes. The CCAT catalyst system offers an integrated and cooperative catalytic

  19. [An analysis of the Ministry of Health of Brazil investments in research and development between 2000-2002: a base line towards future valuations beginning with the implementation of the National Health Research Priority Agenda]. (United States)

    Caetano, Rosângela; Vianna, Cid Manso de Mello; Sampaio, Mariana Miranda Autran; da Silva, Rondineli Mendes; Rodrigues, Rodolfo Rego Deusdará


    The aim of this paper is to examine the Ministry of Health of Brazil investments in research and development in health (R&D/H) between the years of 2000-2002, trying to contrast them with the items of the National Health Research Priority Agenda, in order to attempt a base line that makes capable future evaluations on the inductor role. The data was collected by a research carried out with the main goal of measure resources invested in R&D/H in the country on the period, considering only the Ministry of Health investments. The researches were independently categorized by 2 researchers based on 24 subdivisions which compose the Agenda. The amount of the resources invested by the Ministry of Health on the period was of R$ 199.3 millions. Most of the expense was related to researches in transmittable diseases (31.5%), followed by systems and policies in health (16.3%) and communication and information in health (8.6%). Conditions that represent a substantial disease burden (non transmittable diseases, mental health, violence, accidents and traumas, elderly person health) received relative small amount of resource. The work establishes a starting point from which managers of scientific and technological policy may assess the progressive influence of the Agenda and the reduction of the identified imbalances.

  20. Development of catalysts and ligands for enantioselective gold catalysis. (United States)

    Wang, Yi-Ming; Lackner, Aaron D; Toste, F Dean


    During the past decade, the use of Au(I) complexes for the catalytic activation of C-C π-bonds has been investigated intensely. Over this time period, the development of homogeneous gold catalysis has been extraordinarily rapid and has yielded a host of mild and selective methods for the formation of carbon-carbon and carbon-heteroatom bonds. The facile formation of new bonds facilitated by gold naturally led to efforts toward rendering these transformations enantioselective. In this Account, we survey the development of catalysts and ligands for enantioselective gold catalysis by our research group as well as related work by others. We also discuss some of our strategies to address the challenges of enantioselective gold(I) catalysis. Early on, our work with enantioselective gold-catalyzed transformations focused on bis(phosphinegold) complexes derived from axially chiral scaffolds. Although these complexes were highly successful in some reactions like cyclopropanation, the careful choice of the weakly coordinating ligand (or counterion) was necessary to obtain high levels of enantioselectivity for the case of allene hydroamination. These counterion effects led us to use the anion itself as a source of chirality, which was successful in the case of allene hydroalkoxylation. In general, these tactics enhance the steric influence around the reactive gold center beyond the two-coordinate ligand environment. The use of binuclear complexes allowed us to use the second gold center and its associated ligand (or counterion) to exert a further steric influence. In a similar vein, we employed a chiral anion (in place of or in addition to a chiral ligand) to move the chiral information closer to the reactive center. In order to expand the scope of reactions amenable to enantioselective gold catalysis to cycloadditions and other carbocyclization processes, we also developed a new class of mononuclear phosphite and phosphoramidite ligands to supplement the previously widely

  1. Math Learning Begins at Home (United States)

    Eason, Sarah H.; Levine, Susan C.


    Children demonstrate gaps in the math knowledge that they possess by the time they begin school, and these gaps have been found to predict long-term outcomes not only in math but also in reading. Consequently, it is important to identify what accounts for these early differences and how they can be addressed to ensure that all children enter…

  2. In the beginning was information

    CERN Document Server

    Gitt, Werner, Dr


    Information is the cornerstone of life, yet it is something people don't often think about. In his fascinating new book, In the Beginning Was Information, Dr. Werner Gitt helps the reader see how the very presence of information reveals a Designer.

  3. Catalysis looks to the future. Panel on new directions in catalytic science and technology

    Energy Technology Data Exchange (ETDEWEB)


    Catalysts play a vital role in providing society with fuels, commodity and fine chemicals, pharmaceuticals, and means for protecting the environment. To be useful, a good catalyst must have a high turnover frequency (activity), produce the right kind of product (selectivity), and have a long life (durability), all at an acceptable cost. Research in the field of catalysis provides the tools and understanding required to facilitate and accelerate the development of improved catalysts and to open opportunities for the discovery of new catalytic processes. The aim of this report is to identify the research opportunities and challenges for catalysis in the coming decades and to detail the resources necessary to ensure steady progress. Chapter 2 discusses opportunities for developing new catalysts to meet the demands of the chemical and fuel industries, and the increasing role of catalysis in environmental protection. The intellectual challenges for advancing the frontiers of catalytic science are outlined in Chapter 3. The human and institutional resources available in the US for carrying out research on catalysis are summarized in Chapter 4. The findings and recommendations of the panel for industry, academe, the national laboratories, and the federal government are presented in Chapter 5.

  4. Bimetallic redox synergy in oxidative palladium catalysis. (United States)

    Powers, David C; Ritter, Tobias


    Polynuclear transition metal complexes, which are embedded in the active sites of many metalloenzymes, are responsible for effecting a diverse array of oxidation reactions in nature. The range of chemical transformations remains unparalleled in the laboratory. With few noteworthy exceptions, chemists have primarily focused on mononuclear transition metal complexes in developing homogeneous catalysis. Our group is interested in the development of carbon-heteroatom bond-forming reactions, with a particular focus on identifying reactions that can be applied to the synthesis of complex molecules. In this context, we have hypothesized that bimetallic redox chemistry, in which two metals participate synergistically, may lower the activation barriers to redox transformations relevant to catalysis. In this Account, we discuss redox chemistry of binuclear Pd complexes and examine the role of binuclear intermediates in Pd-catalyzed oxidation reactions. Stoichiometric organometallic studies of the oxidation of binuclear Pd(II) complexes to binuclear Pd(III) complexes and subsequent C-X reductive elimination from the resulting binuclear Pd(III) complexes have confirmed the viability of C-X bond-forming reactions mediated by binuclear Pd(III) complexes. Metal-metal bond formation, which proceeds concurrently with oxidation of binuclear Pd(II) complexes, can lower the activation barrier for oxidation. We also discuss experimental and theoretical work that suggests that C-X reductive elimination is also facilitated by redox cooperation of both metals during reductive elimination. The effect of ligand modification on the structure and reactivity of binuclear Pd(III) complexes will be presented in light of the impact that ligand structure can exert on the structure and reactivity of binuclear Pd(III) complexes. Historically, oxidation reactions similar to those discussed here have been proposed to proceed via mononuclear Pd(IV) intermediates, and the hypothesis of mononuclear Pd

  5. Characterization techniques for graphene-based materials in catalysis

    Directory of Open Access Journals (Sweden)

    Maocong Hu


    Full Text Available Graphene-based materials have been studied in a wide range of applications including catalysis due to the outstanding electronic, thermal, and mechanical properties. The unprecedented features of graphene-based catalysts, which are believed to be responsible for their superior performance, have been characterized by many techniques. In this article, we comprehensively summarized the characterization methods covering bulk and surface structure analysis, chemisorption ability determination, and reaction mechanism investigation. We reviewed the advantages/disadvantages of different techniques including Raman spectroscopy, X-ray photoelectron spectroscopy (XPS, Fourier transform infrared spectroscopy (FTIR and Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS, X-Ray diffraction (XRD, X-ray absorption near edge structure (XANES and X-ray absorption fine structure (XAFS, atomic force microscopy (AFM, scanning electron microscopy (SEM, transmission electron microscopy (TEM, high-resolution transmission electron microscopy (HRTEM, ultraviolet-visible spectroscopy (UV-vis, X-ray fluorescence (XRF, inductively coupled plasma mass spectrometry (ICP, thermogravimetric analysis (TGA, Brunauer–Emmett–Teller (BET, and scanning tunneling microscopy (STM. The application of temperature-programmed reduction (TPR, CO chemisorption, and NH3/CO2-temperature-programmed desorption (TPD was also briefly introduced. Finally, we discussed the challenges and provided possible suggestions on choosing characterization techniques. This review provides key information to catalysis community to adopt suitable characterization techniques for their research.

  6. Redox Catalysis over Metallo-Zeolites. Contribution to Environmental Catalysis

    Czech Academy of Sciences Publication Activity Database

    Wichterlová, Blanka; Sobalík, Zdeněk; Dědeček, Jiří


    Roč. 41, - (2003), s. 97-114 ISSN 0926-3373 R&D Projects: GA AV ČR IBS4040016; GA AV ČR IAA4040007 Institutional research plan: CEZ:AV0Z4040901 Keywords : metallo-zeolites * Co-beta * Fe-ZSM-5 Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.476, year: 2003

  7. Aggregation Processes with Catalysis-Driven Decomposition

    International Nuclear Information System (INIS)

    Xiang Rong; Zhuang Youyi; Ke Jianhong; Lin Zhenquan


    We propose a three-species aggregation model with catalysis-driven decomposition. Based on the mean-field rate equations, we investigate the evolution behavior of the system with the size-dependent catalysis-driven decomposition rate J(i; j; k) = Jijk v and the constant aggregation rates. The results show that the cluster size distribution of the species without decomposition can always obey the conventional scaling law in the case of 0 ≤ v ≤ 1, while the kinetic evolution of the decomposed species depends crucially on the index v. Moreover, the total size of the species without decomposition can keep a nonzero value at large times, while the total size of the decomposed species decreases exponentially with time and vanishes finally. (general)

  8. Transition metal catalysis in confined spaces. (United States)

    Leenders, Stefan H A M; Gramage-Doria, Rafael; de Bruin, Bas; Reek, Joost N H


    Transition metal catalysis plays an important role in both industry and in academia where selectivity, activity and stability are crucial parameters to control. Next to changing the structure of the ligand, introducing a confined space as a second coordination sphere around a metal catalyst has recently been shown to be a viable method to induce new selectivity and activity in transition metal catalysis. In this review we focus on supramolecular strategies to encapsulate transition metal complexes with the aim of controlling the selectivity via the second coordination sphere. As we will discuss, catalyst confinement can result in selective processes that are impossible or difficult to achieve by traditional methods. We will describe the template-ligand approach as well as the host-guest approach to arrive at such supramolecular systems and discuss how the performance of the catalyst is enhanced by confining it in a molecular container.

  9. Approaches to single-nanoparticle catalysis. (United States)

    Sambur, Justin B; Chen, Peng


    Nanoparticles are among the most important industrial catalysts, with applications ranging from chemical manufacturing to energy conversion and storage. Heterogeneity is a general feature among these nanoparticles, with their individual differences in size, shape, and surface sites leading to variable, particle-specific catalytic activity. Assessing the activity of individual nanoparticles, preferably with subparticle resolution, is thus desired and vital to the development of efficient catalysts. It is challenging to measure the activity of single-nanoparticle catalysts, however. Several experimental approaches have been developed to monitor catalysis on single nanoparticles, including electrochemical methods, single-molecule fluorescence microscopy, surface plasmon resonance spectroscopy, X-ray microscopy, and surface-enhanced Raman spectroscopy. This review focuses on these experimental approaches, the associated methods and strategies, and selected applications in studying single-nanoparticle catalysis with chemical selectivity, sensitivity, or subparticle spatial resolution.


    Directory of Open Access Journals (Sweden)



    Full Text Available Electrochemical promotion (EP of catalysis has already been recognized as “a valuable development in catalytic research” (J. Pritchard, 1990 and as “one of the most remarkable advances in electrochemistry since 1950” (J. O’M. Bockris, 1996. Laboratory studies have clearly elucidated the phenomenology of electrochemical promotion and have proven that EP is a general phenomenon at the interface of catalysis and electrochemistry. The major progress toward practical utilization of EP is surveyed in this paper. The focus is given on the electropromotion of industrial ammonia synthesis catalyst, the bipolar EP and the development of a novel monolithic electropromoted reactor (MEPR in conjunction with the electropromotion of thin sputtered metal films. Future perspectives of electrochemical promotion applications in the field of hydrogen technologies are discussed.

  11. Symmetry and asymmetry in mandelate racemase catalysis

    International Nuclear Information System (INIS)

    Whitman, C.P.; Hegeman, G.D.; Cleland, W.W.; Kenyon, G.L.


    Kinetic properties of mandelate racemase catalysis (Vmax, Km, deuterium isotope effects, and pH profiles) were all measured in both directions by the circular dichroic assay of Sharp. These results, along with those of studying interactions of mandelate racemase with resolved, enantiomeric competitive inhibitors [(R)- and (S)-alpha-phenylglycerates], indicate a high degree of symmetry in both binding and catalysis. Racemization of either enantiomer of mandelate in D 2 O did not show an overshoot region of molecular ellipticity in circular dichroic measurements upon approach to equilibrium. Both the absence of such an overshoot region and the high degree of kinetic symmetry are consistent with a one-base acceptor mechanism for mandelate racemase. On the other hand, results of irreversible inhibition with partially resolved, enantiomeric affinity labels [(R)- and (S)-alpha-phenylglycidates] reveal a ''functional asymmetry'' at the active site. Mechanistic proposals, consistent with these results, are presented

  12. Supported Ionic Liquid Phase (SILP) catalysis

    DEFF Research Database (Denmark)

    Riisager, Anders; Fehrmann, Rasmus; Haumann, Marco


    Applications of ionic liquids to replace conventional solvents in homogeneous transition-metal catalysis have increased significantly during the last decade. Biphasic ionic liquid/organic liquid systems offer advantages with regard to product separation, catalyst stability, and recycling but util......Applications of ionic liquids to replace conventional solvents in homogeneous transition-metal catalysis have increased significantly during the last decade. Biphasic ionic liquid/organic liquid systems offer advantages with regard to product separation, catalyst stability, and recycling...... concept is surveyed by presenting results for the continuous gas-phase hydroformylation of propene, as a reaction example. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006....

  13. Nanoscale Advances in Catalysis and Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yimin; Somorjai, Gabor A.


    In this perspective, we present an overview of nanoscience applications in catalysis, energy conversion, and energy conservation technologies. We discuss how novel physical and chemical properties of nanomaterials can be applied and engineered to meet the advanced material requirements in the new generation of chemical and energy conversion devices. We highlight some of the latest advances in these nanotechnologies and provide an outlook at the major challenges for further developments.

  14. Predictive Modeling in Actinide Chemistry and Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    These are slides from a presentation on predictive modeling in actinide chemistry and catalysis. The following topics are covered in these slides: Structures, bonding, and reactivity (bonding can be quantified by optical probes and theory, and electronic structures and reaction mechanisms of actinide complexes); Magnetic resonance properties (transition metal catalysts with multi-nuclear centers, and NMR/EPR parameters); Moving to more complex systems (surface chemistry of nanomaterials, and interactions of ligands with nanoparticles); Path forward and conclusions.

  15. USD Catalysis Group for Alternative Energy

    Energy Technology Data Exchange (ETDEWEB)

    Hoefelmeyer, James D.; Koodali, Ranjit; Sereda, Grigoriy; Engebretson, Dan; Fong, Hao; Puszynski, Jan; Shende, Rajesh; Ahrenkiel, Phil


    The South Dakota Catalysis Group (SDCG) is a collaborative project with mission to develop advanced catalysts for energy conversion with two primary goals: (1) develop photocatalytic systems in which polyfunctionalized TiO2 are the basis for hydrogen/oxygen synthesis from water and sunlight (solar fuels group), (2) develop new materials for hydrogen utilization in fuel cells (fuel cell group). In tandem, these technologies complete a closed chemical cycle with zero emissions.

  16. Catalysis in micellar and macromoleular systems

    CERN Document Server

    Fendler, Janos


    Catalysis in Micellar and Macromolecular Systems provides a comprehensive monograph on the catalyses elicited by aqueous and nonaqueous micelles, synthetic and naturally occurring polymers, and phase-transfer catalysts. It delineates the principles involved in designing appropriate catalytic systems throughout. Additionally, an attempt has been made to tabulate the available data exhaustively. The book discusses the preparation and purification of surfactants; the physical and chemical properties of surfactants and micelles; solubilization in aqueous micellar systems; and the principles of

  17. Asymmetric Aminalization via Cation-Binding Catalysis

    DEFF Research Database (Denmark)

    Park, Sang Yeon; Liu, Yidong; Oh, Joong Suk


    Asymmetric cation-binding catalysis, in principle, can generate "chiral" anionic nucleophiles, where the counter cations are coordinated within chiral environments. Nitrogen-nucleophiles are intrinsically basic, therefore, its use as nucleophiles is often challenging and limiting the scope...... of the reaction. Particularly, a formation of configurationally labile aminal centers with alkyl substituents has been a formidable challenge due to the enamine/imine equilibrium of electrophilic substrates. Herein, we report enantioselective nucleophilic addition reactions of potassium phthalimides to Boc-protected...

  18. Electromagnetic field redistribution induced selective plasmon driven surface catalysis in metal nanowire-film systems. (United States)

    Pan, Liang; Huang, Yingzhou; Yang, Yanna; Xiong, Wen; Chen, Guo; Su, Xun; Wei, Hua; Wang, Shuxia; Wen, Weijia


    For the novel interpretation of Raman spectrum from molecule at metal surface, the plasmon driven surface catalysis (PDSC) reactions have become an interesting topic in the research field of surface enhanced Raman scattering (SERS). In this work, the selective PDSC reactions of p,p'-dimercaptoazobenzene (DMAB) produced from para-aminothiophenol (PATP) or 4-nitrobenzenethiol (4NBT) were demonstrated in the Ag nanowires dimer-Au film systems. The different SERS spectra collected at individual part and adjacent part of the same nanowire-film system pointed out the importance of the electromagnetic field redistribution induced by image charge on film in this selective surface catalysis, which was confirmed by the simulated electromagnetic simulated electro- magnetic field distributions. Our result indicated this electromagnetic field redistribution induced selective surface catalysis was largely affected by the polarization and wavelength of incident light but slightly by the difference in diameters between two nanowires. Our work provides a further understanding of PDSC reaction in metal nanostructure and could be a deep support for the researches on surface catalysis and surface analysis.

  19. From the beginning of radon therapy

    International Nuclear Information System (INIS)

    Schuettmann, W.


    The revival of the radon therapy in several countries since the end of the Second World War was the occasion for a review to the beginnings of this special form of radiotherapy. Initially the early history of radioactivity research is described which among others led to the detection of the emanation as a daughter product of radium. After this followed the evidence of the emanation as a constituent of the natural atmosphere. The establishment of its presence in spring-waters led to the knowledge that there are more than average concentrations of emanation in several mineral springs. In the second part of the article the therapeutic use of the natural radon springs initiated by this is described in its development and importance for Austria (Badgastein, St. Joachimsthal) and Germany (Bad Brambach) up to the beginning of the First World War. (author)

  20. Search for Erzion nuclear catalysis chains from cosmic ray Erzions stopping in organic scintillator

    International Nuclear Information System (INIS)

    Bazhutov, Yu.N.; Pletnikov, E.V.


    In the framework of Erzion model, charged cosmic ray Erzions stopping in organic substance begin to create Erzion nuclear catalysis chains with frequency of ∼ 100 MHz during ∼ 10-100 ms. Using an organic substance (plastic) scintillator we can observe long and flat (10-100 ms) pulses of large amplitude (∼100 MeV). No elementary particle can imitate such pulses. It is expected that such pulses in a plastic scintillator with mass of 100 kg will appear at the sea level every week. Such pulses can be observed every day with the Spectrometric Scintillation Super-Telescope (SSTIS) built at IZMIRAN for cosmic rays monitoring. (authors)

  1. Computational approaches to homogeneous gold catalysis. (United States)

    Faza, Olalla Nieto; López, Carlos Silva


    Homogenous gold catalysis has been exploding for the last decade at an outstanding pace. The best described reactivity of Au(I) and Au(III) species is based on gold's properties as a soft Lewis acid, but new reactivity patterns have recently emerged which further expand the range of transformations achievable using gold catalysis, with examples of dual gold activation, hydrogenation reactions, or Au(I)/Au(III) catalytic cycles.In this scenario, to develop fully all these new possibilities, the use of computational tools to understand at an atomistic level of detail the complete role of gold as a catalyst is unavoidable. In this work we aim to provide a comprehensive review of the available benchmark works on methodological options to study homogenous gold catalysis in the hope that this effort can help guide the choice of method in future mechanistic studies involving gold complexes. This is relevant because a representative number of current mechanistic studies still use methods which have been reported as inappropriate and dangerously inaccurate for this chemistry.Together with this, we describe a number of recent mechanistic studies where computational chemistry has provided relevant insights into non-conventional reaction paths, unexpected selectivities or novel reactivity, which illustrate the complexity behind gold-mediated organic chemistry.

  2. Hybrid Amyloid Membranes for Continuous Flow Catalysis. (United States)

    Bolisetty, Sreenath; Arcari, Mario; Adamcik, Jozef; Mezzenga, Raffaele


    Amyloid fibrils are promising nanomaterials for technological applications such as biosensors, tissue engineering, drug delivery, and optoelectronics. Here we show that amyloid-metal nanoparticle hybrids can be used both as efficient active materials for wet catalysis and as membranes for continuous flow catalysis applications. Initially, amyloid fibrils generated in vitro from the nontoxic β-lactoglobulin protein act as templates for the synthesis of gold and palladium metal nanoparticles from salt precursors. The resulting hybrids possess catalytic features as demonstrated by evaluating their activity in a model catalytic reaction in water, e.g., the reduction of 4-nitrophenol into 4-aminophenol, with the rate constant of the reduction increasing with the concentration of amyloid-nanoparticle hybrids. Importantly, the same nanoparticles adsorbed onto fibrils surface show improved catalytic efficiency compared to the same unattached particles, pointing at the important role played by the amyloid fibril templates. Then, filter membranes are prepared from the metal nanoparticle-decorated amyloid fibrils by vacuum filtration. The resulting membranes serve as efficient flow catalysis active materials, with a complete catalytic conversion achieved within a single flow passage of a feeding solution through the membrane.

  3. Advanced electron microscopy characterization of nanomaterials for catalysis

    Directory of Open Access Journals (Sweden)

    Dong Su


    Full Text Available Transmission electron microscopy (TEM has become one of the most powerful techniques in the fields of material science, inorganic chemistry and nanotechnology. In terms of resolutions, advanced TEM may reach a high spatial resolution of 0.05 nm, a high energy-resolution of 7 meV. In addition, in situ TEM can help researchers to image the process happened within 1 ms. This paper reviews the recent technical progresses of applying advanced TEM characterization on nanomaterials for catalysis. The text is organized based on the perspective of application: for example, size, composition, phase, strain, and morphology. The electron beam induced effect and in situ TEM are also introduced. I hope this review can help the scientists in related fields to take advantage of advanced TEM to their own researches. Keywords: Advanced TEM, Nanomaterials, Catalysts, In situ

  4. Exploring Beginning Teachers' Attrition in the Netherlands (United States)

    den Brok, Perry; Wubbels, Theo; van Tartwijk, Jan


    Based on a review of recent studies and reports, this research investigates attrition among beginning teachers in the Netherlands as well as reasons for teacher attrition, and compares the finding with studies on this topic conducted elsewhere in the world. The findings suggest that attrition among beginning teachers in the Netherlands with a…

  5. Virtual Special Issue on Catalysis at the U.S. Department of Energy’s National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Pruski, Marek; Sadow, Aaron; Slowing, Igor; Marshall, Christopher L.; Stair, Peter C.; Rodriguez, Jose A.; Harris, Alex; Somorjai, Gabor A.; Biener, Juergen; Matranga, Christopher; Wang, Congjian; Schaidle, Josh; Beckham, Gregg T.; Ruddy, Daniel A.; Deutsch, Todd; Alia, Shaun; Narula, Chaitanya; Overbury, Steven H.; Toops, Todd J.; Bullock, R. Morris; Peden, Charles HF; Wang, Yong; Allendorf, Mark D.; Norskov, Jens K.; Bligaard, Thomas


    Catalysis research at the U.S. Department of Energy's (DOE's) National Laboratories covers a wide range of research topics in heterogeneous catalysis, homogeneous/ molecular catalysis, electrocatalysis, and surface science. Since much of the work at National Laboratories is funded by DOE, the research is largely focused on addressing DOE’s mission to ensure America’s security and prosperity by addressing its energy, environmental, and nuclear challenges through trans-formative science and technology solutions. The catalysis research carried out at the DOE National Laboratories ranges from very fundamental catalysis science, funded by DOE’s Office of Basic Energy Sciences (BES), to applied research and development (R&D) in areas such as biomass conversion to fuels and chemicals, fuel cells, and vehicle emission control with primary funding from DOE’s Office of Energy Efficiency and Renewable Energy. National Laboratories are home to many DOE Office of Science national scientific user facilities that provide researchers with the most advanced tools of modern science, including accelerators, colliders, supercomputers, light sources, and neutron sources, as well as facilities for studying the nanoworld and the terrestrial environment. National Laboratory research programs typically feature teams of researchers working closely together, often joining scientists from different disciplines to attack scientific and technical problems using a variety of tools and techniques available at the DOE national scientific user facilities. Along with collaboration between National Laboratory scientists, interactions with university colleagues are common in National Laboratory catalysis R&D. In some cases, scientists have joint appoint-ments at a university and a National Laboratory.

  6. Virtual Special Issue on Catalysis at the U.S. Department of Energy’s National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Pruski, Marek; Sadow, Aaron D.; Slowing, Igor I.; Marshall, Christopher L.; Stair, Peter; Rodriguez, Jose; Harris, Alex; Somorjai, Gabor A.; Biener, Juergen; Matranga, Christopher; Wang, Congjun; Schaidle, Joshua A.; Beckham, Gregg T.; Ruddy, Daniel A.; Deutsch, Todd; Alia, Shaun M.; Narula, Chaitanya; Overbury, Steve; Toops, Todd; Bullock, R. Morris; Peden, Charles H. F.; Wang, Yong; Allendorf, Mark D.; Nørskov, Jens; Bligaard, Thomas


    Catalysis research at the U.S. Department of Energy’s (DOE’s) National Laboratories covers a wide range of research topics in heterogeneous catalysis, homogeneous/molecular catalysis, biocatalysis, electrocatalysis, and surface science. Since much of the work at National Laboratories is funded by DOE, the research is largely focused on addressing DOE’s mission to ensure America’s security and prosperity by addressing its energy, environmental, and nuclear challenges through transformative science and technology solutions. The catalysis research carried out at the DOE National Laboratories ranges from very fundamental catalysis science, funded by DOE’s Office of Basic Energy Sciences (BES), to applied research and development (R&D) in areas such as biomass conversion to fuels and chemicals, fuel cells, and vehicle emission control with primary funding from DOE’s Office of Energy Efficiency and Renewable Energy. National Laboratories are home to many DOE Office of Science national scientific user facilities that provide researchers with the most advanced tools of modern science, including accelerators, colliders, supercomputers, light sources, and neutron sources, as well as facilities for studying the nanoworld and the terrestrial environment. National Laboratory research programs typically feature teams of researchers working closely together, often joining scientists from different disciplines to tackle scientific and technical problems using a variety of tools and techniques available at the DOE national scientific user facilities. Along with collaboration between National Laboratory scientists, interactions with university colleagues are common in National Laboratory catalysis R&D. In some cases, scientists have joint appointments at a university and a National Laboratory.

  7. SPIG From Beginning To Today (United States)

    Labat, J.


    Rapid growth of nuclear physics in fifties attracted attention of numerous scientists, mainly physicists. At the same time, governments become interested in the field, expecting various advantages, and to be honest, in the first place the nuclear weapons. As a result, also in the country at that time called Yugoslavia, the Federal Nuclear Agency has been formed, and generously funds have been given to support the research. In Yugoslavia three nuclear centers have been founded: in Belgrade (Serbia), Zagreb (Croatia) and Ljubljana (Slovenia). The nuclear research and applications to related fields, inevitably was related to the physics of ionized gases. Just to mention electro-magnetic separation of isotopes, mass spectrometry, gas filled nuclear radiation detectors, accelerator ion sources, sources for analytical spectroscopy and others. Right from the beginning a common problem has been met: lack of basic knowledge on elementary collision processes and in general on the matter in ionized state. Groups of physicists in the mentioned institutes have started paying full attention to these problems. They found it of interest to exchange the results and cooperate not only between themselves but also with research centers in other countries. It was felt that at least one national meeting should be organized, where an overview of activities in the field of ionized gases could be presented. Thanks to extraordinary efforts of prof. B. Perovic, supported, backed and simulated by prof. A. Milojevic, prof. Z. Sternberg, prof. Dj. Bosan and prof. A. Moljk first such meeting was prepared. In 1962 the "Ist Yugoslav Symposium an the Physics of Ionized Gases" was organized in Belgrade. Six invited lectures and 26 original contributions were presented. Two years later, in 1964, the second meeting of the same title was held in Zagreb (Croatia). The large number of participants and unexpected interest in field has initiated an idea that the study of different fields related to the

  8. Special Issue: Coinage Metal (Copper, Silver, and Gold Catalysis

    Directory of Open Access Journals (Sweden)

    Sónia Alexandra Correia Carabineiro


    Full Text Available The subject of catalysis by coinage metals (copper, silver, and gold comes up increasingly day-by-day. This Special Issue aims to cover the numerous aspects of the use of these metals as catalysts for several reactions. It deals with synthesis and characterization of copper, silver and gold based catalysis, their characterization and use, both for heterogeneous and homogeneous catalysis, and some of their potential applications.

  9. Special Issue: Coinage Metal (Copper, Silver, and Gold) Catalysis. (United States)

    Carabineiro, Sónia Alexandra Correia


    The subject of catalysis by coinage metals (copper, silver, and gold) comes up increasingly day-by-day. This Special Issue aims to cover the numerous aspects of the use of these metals as catalysts for several reactions. It deals with synthesis and characterization of copper, silver and gold based catalysis, their characterization and use, both for heterogeneous and homogeneous catalysis, and some of their potential applications.

  10. How does interstitial cystitis begin? (United States)

    Parsons, C Lowell


    Interstitial cystitis (IC) does not start as an endstage disease, it has a beginning when symptoms are milder, intermittent and the disease is misdiagnosed. To determine how IC develops patients were interviewed on when their symptoms began, what they were and are now as well as the various diagnoses that they received before they were determined to have IC. One hundred female IC patients were screened. They filled out a questionnaire asking about the age their disease presented, their initial and current symptoms, what their original diagnoses were, effect of the menstrual cycle and sexual activity on their symptoms and about any relatives with bladder symptoms or a current diagnosis of IC. By age 30, 81% of patients had bladder symptoms, 21% before age 10. The first symptom was frequency in 81%, pain present in 59% and the symptoms were intermittent in 64%. Most common early misdiagnosis was UTI in 74% with 93% reporting negative urine cultures. Sex was painful and causes symptom flares in 82%, symptoms flared the week before the menses in 75%. Most common gynecologic diagnosis was yeast vaginitis, 42%. Urge incontinence was present in 33%. There were 51% that reported bladder symptoms in a first degree female relative. IC begins primarily with frequency and is intermittent in most patients with symptom flares associated with sexual activity. Pain and urgency incontinence tend to be a later symptoms. When IC flares the most common misdiagnosis is UTI. Symptoms begin before age 30 in most but an IC diagnosis is often not made until age 40. Genetics appear to play a significant role. It is important to consider these facts when evaluating women with "early IC" because correct diagnosis will result in proper therapy and reduced health care costs.

  11. Synergistic Catalysis: A Powerful Synthetic Strategy for New Reaction Development (United States)

    Allen, Anna E.; MacMillan, David W. C.


    Synergistic catalysis is a synthetic strategy wherein both the nucleophile and the electrophile are simultaneously activated by two separate and distinct catalysts to afford a single chemical transformation. This powerful catalysis strategy leads to several benefits, specifically synergistic catalysis can (i) introduce new, previously unattainable chemical transformations, (ii) improve the efficiency of existing transformations, and (iii) create or improve catalytic enantioselectivity where stereocontrol was previously absent or challenging. This perspective aims to highlight these benefits using many of the successful examples of synergistic catalysis found in the literature. PMID:22518271

  12. Engineering drawing from the beginning

    CERN Document Server

    Cousins, M F


    Engineering Drawing from the Beginning, Volume 2 discusses the methods for communicating technical engineering concepts through illustrations and drawings. This volume covers the more advance techniques in engineering drawing. The coverage of the text includes the helix, which is the path traced by a point moving uniformly around the surface of a right cylinder that is moving axially. The book also covers drawings of solid objects such as prisms, pyramids, and cones, along with hollow objects made from sheet material. In Chapter 5, the text presents the conventional representations of common

  13. Beginning RPG Maker VX Ace

    CERN Document Server

    Perez, Darrin


    Beginning RPG Maker VX Ace takes you through the process of using the RPG Maker VX Ace game development engine to create your very own role playing game. The book has been designed with the complete beginner in mind who has little to no experience with the engine. Tutorials and exercises will take you from installing the software to putting the final touches upon your first project. Game design can be quite a daunting challenge, as it generally involves a large amount of programming know-how on top of having to plan everything out that makes a good game what it is. RPG Maker VX Ace

  14. Beginning SQL Server 2008 Administration

    CERN Document Server

    Walters, R


    Beginning SQL Server 2008 Administration is essential for anyone wishing to learn about implementing and managing SQL Server 2008 database. From college students, to experienced database administrators from other platforms, to those already familiar with SQL Server and wanting to fill in some gaps of knowledge, this book will bring all readers up to speed on the enterprise platform Microsoft SQL Server 2008. * Clearly describes relational database concepts* Explains the SQL Server database engine and supporting tools* Shows various database maintenance scenarios What you'll learn* Understand c

  15. Beginning Windows 8.1

    CERN Document Server

    Halsey, Mike


    Windows 8 has been described by Microsoft as its 'boldest' Windows release ever and the 8.1 update enhances the paradigm further. Beginning Windows 8.1 takes you through the new features and helps you get more out of the familiar to reveal the fullest possibilities for this amazing new operating system. You will learn, with non-technical language used throughout, how to get up and running in the new Windows interface, minimize downtime, maximize productivity, and harness the features you never knew existed to take control of your computer and enjoy the peace of mind and excitement that comes w

  16. Beginning Django E-Commerce

    CERN Document Server

    McGaw, James


    Beginning Django E-Commerce guides you through producing an e-commerce site using Django, the most popular Python web development framework. Topics covered include how to make a shopping cart, a checkout, and a payment processor; how to make the most of Ajax; and search engine optimization best practices. Throughout the book, you'll take each topic and apply it to build a single example site, and all the while you'll learn the theory behind what you're architecting. * Build a fully functional e-commerce site. * Learn to architect your site properly to survive in an increasingly competitive onl

  17. Partnership Cultures: Beginning at the Beginning through Parenting

    Directory of Open Access Journals (Sweden)

    Licia Rando


    Full Text Available Partnership cultures begin with the smallest units of society, the family. Creating partnership families requires evaluating internalized parenting scripts, discarding domination practices, and acting to nurture and form healthy relationships. Care and respect are foundational to partnership parenting, creating a safe environment in which children’s neurophysiologies flourish. Parenting practices that promote safety and calm, such as use of touch and communication that appreciates feelings, buffer children from the effects of stress. Policies and practices that support parents toward partnership -- particularly parents living with overwhelming stress, depression, addictions, and/or childhood histories of abuse and neglect -- may improve children’s lifetime physical and mental health outcomes as well as improve our society.

  18. Catalysis and Downsizing in Mg-Based Hydrogen Storage Materials

    Directory of Open Access Journals (Sweden)

    Jianding Li


    Full Text Available Magnesium (Mg-based materials are promising candidates for hydrogen storage due to the low cost, high hydrogen storage capacity and abundant resources of magnesium for the realization of a hydrogen society. However, the sluggish kinetics and strong stability of the metal-hydrogen bonding of Mg-based materials hinder their application, especially for onboard storage. Many researchers are devoted to overcoming these challenges by numerous methods. Here, this review summarizes some advances in the development of Mg-based hydrogen storage materials related to downsizing and catalysis. In particular, the focus is on how downsizing and catalysts affect the hydrogen storage capacity, kinetics and thermodynamics of Mg-based hydrogen storage materials. Finally, the future development and applications of Mg-based hydrogen storage materials is discussed.

  19. REALCAT: A New Platform to Bring Catalysis to the Lightspeed

    Directory of Open Access Journals (Sweden)

    Paul Sébastien


    Full Text Available Catalysis, irrespective of its form can be considered as one of the most important pillars of today’s chemical industry. The development of new catalysts with improved performances is therefore a highly strategic issue. However, the a priori theoretical design of the best catalyst for a desired reaction is not yet possible and a time- and money-consuming experimental phase is still needed to develop a new catalyst for a given reaction. The REALCAT platform described in this paper consists in a complete, unique, integrated and top-level high-throughput technologies workflow that allows a significant acceleration of this kind of research. This is illustrated by some preliminary results of optimization of the operating conditions of glycerol dehydration to acrolein over an heteropolyacid-based supported catalyst. It is shown that using REALCAT high-throughput tools a more than 10-fold acceleration of the operating conditions optimization process is obtained.

  20. Catalysis in electrochemistry: from fundamentals to strategies for fuel cell development

    National Research Council Canada - National Science Library

    Santos, Elizabeth; Schmickler, Wolfgang


    "Catalysis in Electrochemistry: From Fundamentals to Strategies for Fuel Cell Development is a modern, comprehensive reference work on catalysis in electrochemistry, including principles, methods, strategies, and applications...

  1. Synthesis of Nanoparticle Model Systems for Sustainable Catalysis by Gas Aggregation

    DEFF Research Database (Denmark)

    Bodin, Anders

    The overall goal of this thesis is to develop better catalysts for chemical reactions used in sustainable energy storage and environmental protection. Specifically, the thesis presents research on well-defined catalyst model systems of nanoparticles synthesized by magnetron sputtering, gas......-aggregation, and subsequent massfiltering. The thesis opens with a presentation of the broader context of the research, particularly focusing on the societal importance of catalysis, followed by an introduction to the fundamentals of the science of catalysis. Three research projects are then described in individual chapters......-scale that is needed for significant global impact. This study investigates the relationship between catalytic activity for the HER and platinum catalyst loading using well-defined model systems with different loadings of mass-selected 5nm Pt nanoparticles. Using the knowledge gained on these systems, a technoeconomic...

  2. No Smooth Beginning for Spacetime (United States)

    Feldbrugge, Job; Lehners, Jean-Luc; Turok, Neil


    We identify a fundamental obstruction to any theory of the beginning of the Universe, formulated as a semiclassical path integral. The Hartle-Hawking no boundary proposal and Vilenkin's tunneling proposal are examples of such theories. Each may be formulated as the quantum amplitude for obtaining a final 3-geometry by integrating over 4-geometries. We introduce a new mathematical tool—Picard-Lefschetz theory—for defining the semiclassical path integral for gravity. The Lorentzian path integral for quantum cosmology with a positive cosmological constant is mathematically meaningful in this approach, but the Euclidean version is not. The Lorentzian-Picard-Lefschetz formulation yields unambiguous predictions. Unfortunately, the outcome is that primordial tensor (gravitational wave) fluctuations are unsuppressed. We prove a general theorem to this effect, in a wide class of theories.

  3. Comecon links begin to unravel

    International Nuclear Information System (INIS)

    Wood, J.


    The last year has seen a rapid disintegration of Comecon as an economic group and the basis of trade between the East European countries and the Soviet Union is still changing. For the nuclear industry, the most important change in Comecon trade is the Soviet Union's decision to charge for all its services. The Comecon countries share a number of problems, largely with Soviet equipment. The European Community expects to make grants available for some upgrading work but this plan has not met with unqualified enthusiasm. The Comecon countries are losing nuclear generating capacity as Western assessments of their technology are accepted, and conventional capacity is being lost as environment legislation starts to take effect. The danger is that when the economies begin to expand they may be held back by power shortages. (author)

  4. Did the Big Bang begin?

    International Nuclear Information System (INIS)

    Levy-Leblond, J.


    It is argued that the age of the universe may well be numerically finite (20 billion years or so) and conceptually infinite. A new and natural time scale is defined on a physical basis using group-theoretical arguments. An additive notion of time is obtained according to which the age of the universe is indeed infinite. In other words, never did the Big Bang begin. This new time scale is not supposed to replace the ordinary cosmic time scale, but to supplement it (in the same way as rapidity has taken a place by the side of velocity in Einsteinian relativity). The question is discussed within the framework of conventional (big-bang) and classical (nonquantum) cosmology, but could easily be extended to more elaborate views, as the purpose is not so much to modify present theories as to reach a deeper understanding of their meaning

  5. Beginning of Viniculture in France (United States)

    McGovern, Patrick E.; Luley, Benjamin P.; Rovira, Nuria; Mirzoian, Armen; Callahan, Michael P.; Smith, Karen F.; Hall, Gretchen R.; Davidson, Theodore; Henkin, Joshua M.


    Chemical analyses of ancient organic compounds absorbed into the pottery fabrics of imported Etruscan amphoras (ca. 500-475 B.C.) and into a limestone pressing platform (ca. 425-400 B.C.) at the ancient coastal port site of Lattara in southern France provide the earliest biomolecular archaeological evidence for grape wine and viniculture from this country, which is crucial to the later history of wine in Europe and the rest of the world. The data support the hypothesis that export of wine by ship from Etruria in central Italy to southern Mediterranean France fueled an ever-growing market and interest in wine there, which, in turn, as evidenced by the winepress, led to transplantation of the Eurasian grapevine and the beginning of a Celtic industry in France. Herbal and pine resin additives to the Etruscan wine point to the medicinal role of wine in antiquity, as well as a means of preserving it during marine transport.

  6. Asymmetric catalysis in organic synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, S.D.; Click, D.R.; Grumbine, S.K.; Scott, B.L.; Watkins, J.G.


    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The goal of the project was to prepare new catalyst systems, which would perform chemical reactions in an enantioselective manner so as to produce only one of the possible optical isomers of the product molecule. The authors have investigated the use of lanthanide metals bearing both diolate and Schiff-base ligands as catalysts for the enantioselective reduction of prochiral ketones to secondary alcohols. The ligands were prepared from cheap, readily available starting materials, and their synthesis was performed in a ''modular'' manner such that tailoring of specific groups within the ligand could be carried out without repeating the entire synthetic procedure. In addition, they have developed a new ligand system for Group IV and lanthanide-based olefin polymerization catalysts. The ligand system is easily prepared from readily available starting materials and offers the opportunity to rapidly prepare a wide range of closely related ligands that differ only in their substitution patterns at an aromatic ring. When attached to a metal center, the ligand system has the potential to carry out polymerization reactions in a stereocontrolled manner.

  7. Shape-controlled nanostructures in heterogeneous catalysis. (United States)

    Zaera, Francisco


    Nanotechnologies have provided new methods for the preparation of nanomaterials with well-defined sizes and shapes, and many of those procedures have been recently implemented for applications in heterogeneous catalysis. The control of nanoparticle shape in particular offers the promise of a better definition of catalytic activity and selectivity through the optimization of the structure of the catalytic active site. This extension of new nanoparticle synthetic procedures to catalysis is in its early stages, but has shown some promising leads already. Here, we survey the major issues associated with this nanotechnology-catalysis synergy. First, we discuss new possibilities associated with distinguishing between the effects originating from nanoparticle size versus those originating from nanoparticle shape. Next, we survey the information available to date on the use of well-shaped metal and non-metal nanoparticles as active phases to control the surface atom ensembles that define the catalytic site in different catalytic applications. We follow with a brief review of the use of well-defined porous materials for the control of the shape of the space around that catalytic site. A specific example is provided to illustrate how new selective catalysts based on shape-defined nanoparticles can be designed from first principles by using fundamental mechanistic information on the reaction of interest obtained from surface-science experiments and quantum-mechanics calculations. Finally, we conclude with some thoughts on the state of the field in terms of the advances already made, the future potentials, and the possible limitations to be overcome. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Magnetic Catalysis in Graphene Effective Field Theory. (United States)

    DeTar, Carleton; Winterowd, Christopher; Zafeiropoulos, Savvas


    We report on the first calculation of magnetic catalysis at zero temperature in a fully nonperturbative simulation of the graphene effective field theory. Using lattice gauge theory, a nonperturbative analysis of the theory of strongly interacting, massless, (2+1)-dimensional Dirac fermions in the presence of an external magnetic field is performed. We show that in the zero-temperature limit, a nonzero value for the chiral condensate is obtained which signals the spontaneous breaking of chiral symmetry. This result implies a nonzero value for the dynamical mass of the Dirac quasiparticle.

  9. Surface Science Foundations of Catalysis and Nanoscience

    CERN Document Server

    Kolasinski, Kurt K


    Surface science has evolved from being a sub-field of chemistry or physics, and has now established itself as an interdisciplinary topic. Knowledge has developed sufficiently that we can now understand catalysis from a surface science perspective. No-where is the underpinning nature of surface science better illustrated than with nanoscience. Now in its third edition, this successful textbook aims to provide students with an understanding of chemical transformations and the formation of structures at surfaces. The chapters build from simple to more advanced principles with each featuring exerc

  10. Concepts of Modern Catalysis and Kinetics

    CERN Document Server

    Chorkendorff, I


    Until now, the literature has offered a rather limited approach to the use of fundamental kinetics and their application to catalytic reactions. Subsequently, this book spans the full range from fundamentals of kinetics and heterogeneous catalysis via modern experimental and theoretical results of model studies to their equivalent large-scale industrial production processes. The result is key knowledge for students at technical universities and professionals already working in industry. "...such an enterprise will be of great value to the community, to professionals as well as graduate an

  11. Catalysis of chemical processes: Particular teaching aspects | Šima ...

    African Journals Online (AJOL)

    The paper is devoted to two main issues of catalysis from the viewpoint of teaching and learning activities. The first part deals with positive catalysis which treats the general features of catalytic processes and textbook imperfections. The second part focuses on decelerating or stopping-down chemical processes. It is shown ...

  12. Heterogeneous Catalysis with Renewed Attention: Principles, Theories, and Concepts (United States)

    Dumeignil, Franck; Paul, Jean-Francois; Paul, Sebastien


    With the development of a strong bioeconomy sector related to the creation of next-generation biorefineries, heterogeneous catalysis is receiving renewed attention. Indeed, catalysis is at the core of biorefinery design, and many new catalysts and catalytic processes are being developed. On the one hand, they are based on knowledge acquired during…

  13. The nature of the active site in heterogeneous metal catalysis

    DEFF Research Database (Denmark)

    Nørskov, Jens Kehlet; Bligaard, Thomas; Larsen, Britt Hvolbæk


    This tutorial review, of relevance for the surface science and heterogeneous catalysis communities, provides a molecular-level discussion of the nature of the active sites in metal catalysis. Fundamental concepts such as "Bronsted-Evans-Polanyi relations'' and "volcano curves'' are introduced...

  14. Tandem Catalysis Utilizing Olefin Metathesis Reactions. (United States)

    Zieliński, Grzegorz K; Grela, Karol


    Since olefin metathesis transformation has become a favored synthetic tool in organic synthesis, more and more distinct non-metathetical reactions of alkylidene ruthenium complexes have been developed. Depending on the conditions applied, the same olefin metathesis catalysts can efficiently promote isomerization reactions, hydrogenation of C=C double bonds, oxidation reactions, and many others. Importantly, these transformations can be carried out in tandem with olefin metathesis reactions. Through addition of one portion of a catalyst, a tandem process provides structurally advanced products from relatively simple substrates without the need for isolation of the intermediates. These aspects not only make tandem catalysis very attractive from a practical point of view, but also open new avenues in (retro)synthetic planning. However, in the literature, the term "tandem process" is sometimes used improperly to describe other types of multi-reaction sequences. In this Concept, a number of examples of tandem catalysis involving olefin metathesis are discussed with an emphasis on their synthetic value. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Mechanical catalysis on the centimetre scale. (United States)

    Miyashita, Shuhei; Audretsch, Christof; Nagy, Zoltán; Füchslin, Rudolf M; Pfeifer, Rolf


    Enzymes play important roles in catalysing biochemical transaction paths, acting as logical machines through the morphology of the processes. A key challenge in elucidating the nature of these systems, and for engineering manufacturing methods inspired by biochemical reactions, is to attain a comprehensive understanding of the stereochemical ground rules of enzymatic reactions. Here, we present a model of catalysis that can be performed magnetically by centimetre-sized passive floating units. The designed system, which is equipped with permanent magnets only, passively obeys the local causalities imposed by magnetic interactions, albeit it shows a spatial behaviour and an energy profile analogous to those of biochemical enzymes. In this process, the enzyme units trigger physical conformation changes of the target by levelling out the magnetic potential barrier (activation potential) to a funnel type and, thus, induce cascading conformation changes of the targeted substrate units reacting in parallel. The inhibitor units, conversely, suppress such changes by increasing the potential. Because the model is purely mechanical and established on a physics basis in the absence of turbulence, each performance can be explained by the morphology of the unit, extending the definition of catalysis to systems of alternative scales.

  16. Catalysis-Based Cataluminescent and Conductometric Gas Sensors: Sensing Nanomaterials, Mechanism, Applications and Perspectives

    Directory of Open Access Journals (Sweden)

    Jinyun Liu


    Full Text Available Gas environment detection has become more urgent and significant, for both industrial manufacturing and environment monitoring. Gas sensors based on a catalytically-sensing mechanism are one of the most important types of devices for gas detection, and have been of great interest during the past decades. However, even though many efforts have contributed to this area, some great challenges still remain, such as the development of sensitively and selectively sensing catalysts. In this review, two representative catalysis-based gas sensors, cataluminescent and conductometric sensors, the basis of optical and electric signal acquisition, respectively, are summarized comprehensively. The current challenges have been presented. Recent research progress on the working mechanism, sensing nanomaterials, and applications reported by our group and some other researchers have been discussed systematically. The future trends and prospects of the catalysis-based gas sensors have also been presented.

  17. Preparation and Characterisation of Activated Ni(Mn)/Mg/Al Hydrotalcites for Combustion Catalysis

    Czech Academy of Sciences Publication Activity Database

    Jirátová, Květa; Čuba, Pavel; Kovanda, F.; Hilaire, L.; Pitchon, V.


    Roč. 76, č. 1 (2002), s. 43-53 ISSN 0920-5861. [European Congress on Catalysis EuropaCat V /5./. Limerick, 02.09.2001-07.09.2001] R&D Projects: GA ČR GA106/02/0523 Institutional research plan: CEZ:AV0Z4072921 Keywords : hydrotalcites * metal oxide catalysts * methane combustion Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.146, year: 2002

  18. Bio- and air-tolerant carbon–carbon bond formations via organometallic ruthenium catalysis

    Czech Academy of Sciences Publication Activity Database

    Adriaenssens, Louis; Severa, Lukáš; Vávra, Jan; Šálová, Tereza; Hývl, Jakub; Čížková, Martina; Pohl, Radek; Šaman, David; Teplý, Filip


    Roč. 74, 7/8 (2009), s. 1023-1034 ISSN 0010-0765 R&D Projects: GA ČR GA203/09/0705; GA ČR GA203/09/1614 Institutional research plan: CEZ:AV0Z40550506 Keywords : ruthenium * organometallic catalysis * C-C coupling * [2+2+2]cycloadditions Subject RIV: CC - Organic Chemistry Impact factor: 0.856, year: 2009

  19. On the mechanism of hydrogen evolution catalysis by proteins: A case study with bovine serum albumin

    Czech Academy of Sciences Publication Activity Database

    Doneux, T.; Ostatná, Veronika; Paleček, Emil


    Roč. 56, č. 25 (2011), s. 9337-9343 ISSN 0013-4686 R&D Projects: GA MŠk(CZ) ME09038; GA MŠk(CZ) LC06035 Grant - others:GA ČR(CZ) GAP301/11/2055 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : hydrogen evolution reaction * mediated catalysis * proton transfer Subject RIV: BO - Biophysics Impact factor: 3.832, year: 2011

  20. Chiral phosphites as ligands in asymmetric metal complex catalysis and synthesis of coordination compounds

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, Konstantin N [Department of Chemistry, S.A. Esenin Ryazan State Pedagogical University, Ryazan (Russian Federation); Bondarev, Oleg G; Polosukhin, Aleksei I [A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow (Russian Federation)


    The data published during the last five years on the application of chiral derivatives of phosphorous acid in coordination chemistry and enantioselective catalysis are summarised and discussed. The effect of the nature of these ligands on the structure of metal complexes and on the efficiency of catalytic organic syntheses is shown. Hydroformylation, hydrogenation, allylic substitution and conjugate addition catalysed by transition metal complexes with optically active phosphites and hydrophosphoranes are considered. The prospects for the development of this field of research are demonstrated.

  1. Comments on Volcano Curves and Electronic Factors in Catalysis by Metals

    Czech Academy of Sciences Publication Activity Database

    Knor, Zlatko


    Roč. 245, č. 2 (2003), s. 185-189 ISSN 0926-860X R&D Projects: GA ČR GV202/98/K002; GA ČR GA202/02/0618 Institutional research plan: CEZ:AV0Z4040901 Keywords : catalytic activity * catalysis by metals Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.825, year: 2003

  2. Recent Progress in Asymmetric Catalysis and Chromatographic Separation by Chiral Metal–Organic Frameworks

    Directory of Open Access Journals (Sweden)

    Suchandra Bhattacharjee


    Full Text Available Metal–organic frameworks (MOFs, as a new class of porous solid materials, have emerged and their study has established itself very quickly into a productive research field. This short review recaps the recent advancement of chiral MOFs. Here, we present simple, well-ordered instances to classify the mode of synthesis of chiral MOFs, and later demonstrate the potential applications of chiral MOFs in heterogeneous asymmetric catalysis and enantioselective separation. The asymmetric catalysis sections are subdivided based on the types of reactions that have been successfully carried out recently by chiral MOFs. In the part on enantioselective separation, we present the potentiality of chiral MOFs as a stationary phase for high-performance liquid chromatography (HPLC and high-resolution gas chromatography (GC by considering fruitful examples from current research work. We anticipate that this review will provide interest to researchers to design new homochiral MOFs with even greater complexity and effort to execute their potential functions in several fields, such as asymmetric catalysis, enantiomer separation, and chiral recognition.

  3. Did time begin? Will time end?

    CERN Document Server

    Frampton, Paul H


    Did time begin at a Big Bang? Will the present expansion of the universe last for a finite or infinite time? These questions sound philosophical but are becoming, now in the twenty-first century, central to the scientific study of cosmology. The answers, which should become clarified in the next decade or two, could have profound implications for how we see our own role in the universe. Since the original publication of Stephen Hawking's {\\it A Brief History of Time} in 1988, the answers to these questions have progressed as a result of research by the community of active theoretical physicists including myself. To present the underlying ideas requires discussion of a wide range of topics in cosmology, especially the make up of the energy content of the universe. A brief summary of my conclusions, that of three different possibilities concerning the history and future of time, the least likely is the conventional wisdom (time began and will never end) and most likely is a cyclic model (time never begins or en...

  4. Antecedents of Norwegian Beginning Teachers' Turnover Intentions (United States)

    Tiplic, Dijana; Brandmo, Christian; Elstad, Eyvind


    This study aims at exploring several individual, organizational, and contextual factors that may affect beginning teachers' turnover intentions during their first years of practice. The sample consists of 227 beginning teachers (69% female and 31% male) from 133 schools in Norway. The results show four important antecedents of beginning teachers'…

  5. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... to begin as you develop a partnership and treatment plan with your physician. Click here to find a place to begin. Sjögren’s Syndrome: A Place To Begin from Sjögren’s Syndrome Foundation on Vimeo . anxiety and buy , tranquility as well as medication © 2018 ...

  6. Punctuality of tram departing from beginning of tramstop

    Directory of Open Access Journals (Sweden)

    Adam MOLECKI


    Full Text Available The article presents results of researches of punctuality of tram departing from beginning of tramstops in Zagłębie Dąbrowskie. There were analyzed departures at classical tram lines, without light signaling of departing-time. There were inside of driver’s cabs sound signaling of departure. The departure’s punctuality problem from beginning of tramstops is very important to make tram traffic simulations. These ones let to optimalyze traffic engineering solutions.

  7. Reaction mechanism of oxidation, hydroxylation, and epoxidation by hypofluorous acid: A theoretical study of unusual H-bond-assisted catalysis

    Czech Academy of Sciences Publication Activity Database

    Srnec, Martin; Ončák, Milan; Zahradník, Rudolf


    Roč. 112, č. 6 (2008), s. 3631-3637 ISSN 1089-5639 Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40400503 Keywords : hypofluorous acid * self-catalysis * Rozen oxidation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.871, year: 2008

  8. First-principles kinetic modeling in heterogeneous catalysis: an industrial perspective on best-practice, gaps and needs


    Sabbe, Maarten; Reyniers, Marie-Françoise; Reuter, Karsten


    Electronic structure calculations have emerged as a key contributor in modern heterogeneous catalysis research, though their application in chemical reaction engineering remains largely limited to academia. This perspective aims at encouraging the judicious use of first-principles kinetic models in industrial settings based on a critical discussion of present-day best practices, identifying existing gaps, and defining where further progress is needed.

  9. Radicals and Transition-Metal Catalysis: An Alliance Par Excellence to Increase Reactivity and Selectivity in Organic Chemistry

    Czech Academy of Sciences Publication Activity Database

    Ford, Leigh Robert; Jahn, Ullrich


    Roč. 48, č. 35 (2009), s. 6386-6389 ISSN 1433-7851 Institutional research plan: CEZ:AV0Z40550506 Keywords : cross-coupling * elimination * homogeneous catalysis * hydrogen transfer * radicals Subject RIV: CC - Organic Chemistry Impact factor: 11.829, year: 2009

  10. Novel Catalysis by Gold: A Modern Alchemy (United States)

    Haruta, Masatake

    Gold has long been neglected as a catalyst because of its chemical inertness. However, when gold is deposited as nanoparticles on carbon and polymer materials as well as on base metal oxides and hydroxides, it exhibits unique catalytic properties for many reactions such as CO oxidation at a temperature as low as 200 K, gas phase direct epoxidation of propylene, and aerobic oxidation of glucose to gluconic acid. The structure-catalytic activity correlations are discussed with emphasis on the contact structure, support selection, and the size control of gold particles. Gold clusters with diameters smaller than 2 nm are expected to exhibit novel properties in catalysis, optics, and electronics depending on the size (number of atoms), shape, and the electronic and chemical interaction with the support materials. The above achievements and attempts can be regarded as a modern alchemy that creates valuables by means of the noblest element with little practical use.

  11. Heterogeneous Organo-Catalysis: Sustainable Pathways to ... (United States)

    Glucose and fructose are among the most abundant plant-derived materials1 and have been converted into useful building units often used in the drug discovery and polymer architecture.2 Unfortunately, most of these conversions require mineral acids and complex heterogeneous catalysis systems which suffer from the diminished activity and recyclability issues.3 Herein, we report a highly reactive and inexpensive heterogeneous sulfonated graphitic carbon nitride (Sg-CN), endowed with strong acidity that readily transforms carbohydrates to furanics. The ready availability and benign nature of the material and its stability over the several reaction cycles renders this catalyst very useful in organic synthesis, polymer industry and in the preparation of drug precursors. Poster presentation at the 253rd American Chemical Society (ACS) National meeting in San Francisco, CA

  12. Catalysis in solid oxide fuel cells. (United States)

    Gorte, R J; Vohs, J M


    Solid oxide fuel cells (SOFCs) and solid oxide electrolyzers (SOEs) hold much promise as highly efficient devices for the direct interconversion of chemical and electrical energy. Commercial application of these devices, however, requires further improvements in their performance and stability. Because the performance of SOFC and SOE electrodes depends on their microstructures, electronic and ionic conductivities, and chemical reactivities, the needed improvements require the expertise of various disciplines, with catalytic science playing an important role. Highly active and thermally stable catalysts are required to limit the internal losses in the devices, increase the range of fuels they can use, and decrease the temperatures at which they operate. In this article we review some of the most important recent advances in catalysis for SOFC and SOE electrodes and highlight additional improvements that are needed.

  13. Relation between Hydrogen Evolution and Hydrodesulfurization Catalysis

    DEFF Research Database (Denmark)

    Šaric, Manuel; Moses, Poul Georg; Rossmeisl, Jan


    A relation between hydrogen evolution and hydrodesulfurization catalysis was found by density functional theory calculations. The hydrogen evolution reaction and the hydrogenation reaction in hydrodesulfurization share hydrogen as a surface intermediate and, thus, have a common elementary step......, which indicates that the same catalyst should perform well for both hydrogen evolution and hydrogenation. If that catalyst also fulfills additional criteria for breaking carbon–sulfur bonds and releasing hydrogen sulfide, it will be a good hydrodesulfurization catalyst. The hydrogen evolution reaction...... is normally performed at room temperature and standard pressure, whereas the hydrodesulfurization reaction is driven by high temperature and pressure. Owing to the very different operating conditions, the adsorption free energy of hydrogen differs between hydrodesulfurization and the hydrogen evolution...

  14. Heterogeneous catalysis in highly sensitive microreactors

    DEFF Research Database (Denmark)

    Olsen, Jakob Lind

    This thesis present a highly sensitive silicon microreactor and examples of its use in studying catalysis. The experimental setup built for gas handling and temperature control for the microreactor is described. The implementation of LabVIEW interfacing for all the experimental parts makes...... of adsorbates readily converted to methanol as the source of the transient increase in methanol production, is eliminated. A study of mass selected ruthenium nanoparticles from a magnetron-sputter gas-aggregation source, deposited in microreactors, is presented. It is, shown that CO methanation can be measured...... on the mass selected nanoparticles in the microreactor. A parameter study shows negative reaction order in the CO concentration and apparent acivation energies between 0.8 and 1.2 eV depending on reaction conditions. Temperature programmed reaction studies in H2m shows di_erent forms of carbon growth...

  15. µ-reactors for Heterogeneous Catalysis

    DEFF Research Database (Denmark)

    Jensen, Robert

    is described in detail. Since heating and temperature measurement is an extremely important point in heterogeneous catalysis an entire chapter is dedicated to this subject. Three different types of heaters have been implemented and tested both for repeatability and homogeneity of the heating as well...... catalyst surface area by reacting off an adsorbed layer of oxygen with CO. This procedure can be performed at temperatures low enough that sintering of Pt nanoparticles is not an issue. Some results from the reactors are presented. In particular an unexpected oscillation phenomenon of CO-oxidation on Pt...... nanoparticles are presented in detail. The sensitivity of the reactors are currently being investigated with CO oxidation on Pt thin films as a test reaction, and the results so far are presented. We have at this point shown that we are able to reach full conversion with a catalyst area of 38 µm2 with a turn...

  16. Music and Movement. Beginnings Workshop. (United States)

    Smith, Cindy; Moore, Thomas; Carlton, Elizabeth B.; Kranowitz, Carol Stock


    Four articles address music and movement in early childhood education: (1) "For the Love of Music--and Children"(Cindy Smith); (2) "Music: The Great Connector" (Thomas Moore); (3) "Learning through Music: The Support of Brain Research" (Elizabeth B. Carlton); and (4) "Music and Movement Bring Together Children of…

  17. Successively detected events of the multiple muon catalysis process

    International Nuclear Information System (INIS)

    Zinov, V.G.; Somov, L.N.; Fil'chenkov, V.V.


    The kinetics of multiple muon catalysis process is considered. Expressions for the yields and time distributions of successive events of mu-catalysis reactions detected with epsilon 2 +t 2 mixtere are given. These results can be also applied to the synthesis reactions p+d -> 3 He+γ in h 2 d 2 mixture and p+t -> 4 He+γ in h 2 +t 2 mixture. It is shown that the mu-catalysis process parameters and the detection efficiency can be independently determined for the experimental data analysis

  18. Iminium and enamine catalysis in enantioselective photochemical reactions (United States)

    Hörmann, Fabian M.


    Although enantioselective catalysis under thermal conditions has been well established over the last few decades, the enantioselective catalysis of photochemical reactions is still a challenging task resulting from the complex enantiotopic face differentiation in the photoexcited state. Recently, remarkable achievements have been reported by a synergistic combination of organocatalysis and photocatalysis, which have led to the expedient construction of a diverse range of enantioenriched molecules which are generally not easily accessible under thermal conditions. In this tutorial review, we summarize and highlight the most significant advances in iminium and enamine catalysis of enantioselective photochemical reactions, with an emphasis on catalytic modes and reaction types. PMID:29155908

  19. A new era of catalysis: efficiency, value, and sustainability. (United States)

    Cheng, Soofin; Lin, Shawn D


    Value proposition: Global warming and climate change urge the chemical industry to develop new processes, in which sustainability is a necessity and requirement. Catalysis is recognized to be one of the key technologies in enabling sustainability. This special issue, assembled by guest editors Soofing Chen and Shawn D. Lin, highlights some of the best work presented at "The 6th Asia-Pacific Congress on Catalysis (APCAT-6)", with as major theme "New Era of Catalysis: Efficiency, Value, and Sustainability". © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Microbial electro-catalysis in fuel cell

    International Nuclear Information System (INIS)

    Dumas, Claire


    Microbial fuel cells (MFC) are devices that ensure the direct conversion of organic matter into electricity using bacterial bio-films as the catalysts of the electrochemical reactions. This study aims at improving the comprehension of the mechanisms involved in electron transfer pathways between the adhered bacteria and the electrodes. This optimization of the MFC power output could be done, for example, in exploring and characterizing various electrode materials. The electrolysis experiments carried out on Geobacter sulfurreducens deal with the microbial catalysis of the acetate oxidation, on the one hand, and the catalysis of the fumarate reduction on the other hand. On the anodic side, differences in current densities appeared on graphite, DSA R and stainless steel (8 A/m 2 , 5 A/m 2 and 0.7 A/m 2 respectively). These variations were explained more by materials roughness differences rather than their nature. Impedance spectroscopy study shows that the electro-active bio-film developed on stainless steel does not seem to modify the evolution of the stainless steel oxide layer, only the imposed potential remains determining. On the cathodic side, stainless steel sustained current densities more than twenty times higher than those obtained with graphite electrodes. The adhesion study of G. sulfurreducens on various materials in a flow cell, suggests that the bio-films resist to the hydrodynamic constraints and are not detached under a shear stress threshold value. The installation of two MFC prototypes, one in a sea station and the other directly in Genoa harbour (Italy) confirms some results obtained in laboratory and were promising for a MFC scale-up. (author) [fr

  1. Tactical Combat Casualty Care: Beginnings. (United States)

    Butler, Frank K


    Tactical Combat Casualty Care (TCCC) is a set of evidence-based, best-practice prehospital trauma care guidelines customized for use on the battlefield. The origins of TCCC were nontraditional. The TCCC program began as a Naval Special Warfare biomedical research effort launched after the realization that extremity hemorrhage, a leading cause of preventable death on the battlefield, was not being treated with a readily available and highly effective intervention: the tourniquet. This insight prompted a systematic reevaluation of all aspects of battlefield trauma care that was conducted from 1993 to 1996 as a joint effort by special operations medical personnel and the Uniformed Services University of the Health Sciences. The product of that 3-year research project was TCCC, the first-ever set of battlefield trauma care guidelines designed to combine good medicine with good small-unit tactics. Published by Elsevier Inc.

  2. How Early Childhood Learning Influences Beginning Literacy Teachers' Professional Learning (United States)

    McGlynn-Stewart, Monica


    Research has shown that teachers' beliefs and personal experiences play a significant role in their professional decision-making and practice, including their experiences as school children. This research study examined how the professional learning of Canadian beginning elementary teachers was influenced by their own early learning experiences in…

  3. It all begins with people

    International Nuclear Information System (INIS)

    Downey, M.W.


    This paper examines the question: How important is the role of people in exploration success? Can one quantify the worth of staff contributions versus the contribution of risk capital? Are geologists and geophysicists really necessary for exploration success? Can investments in research and in training and motivating staff be justified on an economic basis? Is intellectual capital a real and measurable benefit to a company? (Intellectual capital is defined as the net value provided an organization by its investment in nonoperating technical staff). Can companies see the worth of their intellectual capital investment reflected in their earnings? Can a corporation afford exploration staff in difficult economic times

  4. Enantioselective Fluorination of Spirocyclic β-Prolinals Using Enamine Catalysis

    DEFF Research Database (Denmark)

    Fjelbye, Kasper; Marigo, Mauro; Clausen, Rasmus Prætorius


    A series of spirocyclic carbaldehydes were successfully fluorinated using enamine catalysis, furnishing the corresponding tertiary fluorides in both high yields and enantioselectivities. The fluorinated spirocycles provide a set of novel building blocks interesting from a medicinal chemistry point...

  5. Density functional theory studies of transition metal nanoparticles in catalysis

    DEFF Research Database (Denmark)

    Greeley, Jeffrey Philip; Rankin, Rees; Zeng, Zhenhua


    Periodic Density Functional Theory calculations are capable of providing powerful insights into the structural, energetics, and electronic phenomena that underlie heterogeneous catalysis on transition metal nanoparticles. Such calculations are now routinely applied to single crystal metal surfaces...... and to subnanometer metal clusters. Descriptions of catalysis on truly nanosized structures, however, are generally not as well developed. In this talk, I will illustrate different approaches to analyzing nanocatalytic phenomena with DFT calculations. I will describe case studies from heterogeneous catalysis...... and electrocatalysis, in which single crystal models are combined with Wulff construction-based ideas to produce descriptions of average nanocatalyst behavior. Then, I will proceed to describe explicitly DFT-based descriptions of catalysis on truly nanosized particles (

  6. Catalysis of Radical Reactions: A Radical Chemistry Perspective. (United States)

    Studer, Armido; Curran, Dennis P


    The area of catalysis of radical reactions has recently flourished. Various reaction conditions have been discovered and explained in terms of catalytic cycles. These cycles rarely stand alone as unique paths from substrates to products. Instead, most radical reactions have innate chains which form products without any catalyst. How do we know if a species added in "catalytic amounts" is a catalyst, an initiator, or something else? Herein we critically address both catalyst-free and catalytic radical reactions through the lens of radical chemistry. Basic principles of kinetics and thermodynamics are used to address problems of initiation, propagation, and inhibition of radical chains. The catalysis of radical reactions differs from other areas of catalysis. Whereas efficient innate chain reactions are difficult to catalyze because individual steps are fast, both inefficient chain processes and non-chain processes afford diverse opportunities for catalysis, as illustrated with selected examples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Applications of metal-organic frameworks in heterogeneous supramolecular catalysis. (United States)

    Liu, Jiewei; Chen, Lianfen; Cui, Hao; Zhang, Jianyong; Zhang, Li; Su, Cheng-Yong


    This review summarizes the use of metal-organic frameworks (MOFs) as a versatile supramolecular platform to develop heterogeneous catalysts for a variety of organic reactions, especially for liquid-phase reactions. Following a background introduction about catalytic relevance to various metal-organic materials, crystal engineering of MOFs, characterization and evaluation methods of MOF catalysis, we categorize catalytic MOFs based on the types of active sites, including coordinatively unsaturated metal sites (CUMs), metalloligands, functional organic sites (FOS), as well as metal nanoparticles (MNPs) embedded in the cavities. Throughout the review, we emphasize the incidental or deliberate formation of active sites, the stability, heterogeneity and shape/size selectivity for MOF catalysis. Finally, we briefly introduce their relevance into photo- and biomimetic catalysis, and compare MOFs with other typical porous solids such as zeolites and mesoporous silica with regard to their different attributes, and provide our view on future trends and developments in MOF-based catalysis.

  8. Toward an Understanding of Catalysis by Supported Metal Nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    D. W. Goodman; J. Wang; B. K. Min; E. Ozensoy; F. Yang


    OAK (B204) The goal of this program is an atomic-level understanding of catalysis by supported metal nanoclusters, especially the surface intermediates in selective oxidation by noble metal nanocatalysts.

  9. Nanostructured Membranes for Green Synthesis of Nanoparticles and Enzyme Catalysis (United States)

    Macroporous membranes functionalized with ionizable macromolecules provide promising applications in toxic metal capture at high capacity, nanoparticle synthesis, and catalysis. Our low‐pressure membrane approach is marked by reaction and separation selectivity and their tunabili...

  10. Nanostructured Membranes for Enzyme Catalysis and Green Synthesis of Nanoparticles (United States)

    Macroporous membranes functionalized with ionizable macromolecules provide promising applications in toxic metal capture at high capacity, nanoparticle synthesis, and catalysis. Our low-pressure membrane approach is marked by reaction and separation selectivity and their tunabil...

  11. Predictive modeling in catalysis - from dream to reality

    NARCIS (Netherlands)

    Maldonado, A.G.; Rothenberg, G.


    In silico catalyst optimization is the ultimate application of computers in catalysis. This article provides an overview of the basic concepts of predictive modeling and describes how this technique can be used in catalyst and reaction design.

  12. Bridging heterogeneous and homogeneous catalysis concepts, strategies, and applications

    CERN Document Server

    Li, Can


    This unique handbook fills the gap in the market for an up-to-date work that links both homogeneous catalysis applied to organic reactions and catalytic reactions on surfaces of heterogeneous catalysts.

  13. Catalysis by metallic nanoparticles in solution: Thermosensitive microgels as nanoreactors


    Roa, Rafael; Angioletti-Uberti, Stefano; Lu, Yan; Dzubiella, Joachim; Piazza, Francesco; Ballauff, Matthias


    Metallic nanoparticles have been used as catalysts for various reactions, and the huge literature on the subject is hard to overlook. In many applications, the nanoparticles must be affixed to a colloidal carrier for easy handling during catalysis. These "passive carriers" (e.g., dendrimers) serve for a controlled synthesis of the nanoparticles and prevent coagulation during catalysis. Recently, hybrids from nanoparticles and polymers have been developed that allow us to change the catalytic ...

  14. 3. International conference on catalysis in membrane reactors

    Energy Technology Data Exchange (ETDEWEB)



    The 3. International Conference on Catalysis in Membrane Reactors, Copenhagen, Denmark, is a continuation of the previous conferences held in Villeurbanne 1994 and Moscow 1996 and will deal with the rapid developments taking place within membranes with emphasis on membrane catalysis. The approx. 80 contributions in form of plenary lectures and posters discuss hydrogen production, methane reforming into syngas, selectivity and specificity of various membranes etc. The conference is organised by the Danish Catalytic Society under the Danish Society for Chemical Engineering. (EG)

  15. Density functional theory studies of transition metal nanoparticles in catalysis

    DEFF Research Database (Denmark)

    Greeley, Jeffrey Philip; Rankin, Rees; Zeng, Zhenhua


    Periodic Density Functional Theory calculations are capable of providing powerful insights into the structural, energetics, and electronic phenomena that underlie heterogeneous catalysis on transition metal nanoparticles. Such calculations are now routinely applied to single crystal metal surfaces...... and electrocatalysis, in which single crystal models are combined with Wulff construction-based ideas to produce descriptions of average nanocatalyst behavior. Then, I will proceed to describe explicitly DFT-based descriptions of catalysis on truly nanosized particles (

  16. Diversifying Homogenous Au(I)-Catalysis through New Reaction Discovery (United States)

    Motika, Stephen

    Homogenous Au(I)-catalysis has become a valuable synthetic tool to activate a host of unsaturated carbon functional groups towards nucleophilic addition. Over the course of the past two decades, many have embarked on new journeys within this field. Notably, the advancements in this field hinge on the development of new ligand systems that impart novel reactivity at the metal. Our group has focused on this area, as we have successfully demonstrated the utility of 1,2,3-triazoles as ligands for gold and a host of other transition metals and Lewis acids. With respect to gold catalysis, these ligands enhance the stability of the metal center, thus inhibiting typical reductive decomposition pathways that have plagued this field. The enhanced stability comes with a price though as higher temperatures can be required. We've addressed this challenge by discovering an interesting synergy between triazole-gold and Lewis acids, allowing us to overcome the lower reactivity of these catalysts. During my time as a graduate student, I have focused heavily on enlisting these catalytic systems for new reaction discovery. In my first experimental chapter, I was able to develop an interesting reaction cascade in which triazole-gold and secondary amine catalysts were used. I started with a well-known gold-catalyzed Claisen rearrangement of propargyl vinyl ether, yielding functionalized allenes. The identical oxidation state between these allenes and synthetically appealing dienals was an impetus to develop a new isomerization strategy. After screening various conditions, I was able to successfully execute this design. Most of the work I have been involved in over the past two years has surrounded a gold-catalyzed hydroboration to yield interesting hetercocycles containing a N-B bond. The N-B bond offers some unique properties as it is isoelectronic to a C-C double bond. Despite the simplicity in this design, it would become apparent early on in this research that mitigating the

  17. Bacterial and Fungal Proteolytic Enzymes: Production, Catalysis and Potential Applications. (United States)

    da Silva, Ronivaldo Rodrigues


    Submerged and solid-state bioprocesses have been extensively explored worldwide and employed in a number of important studies dealing with microbial cultivation for the production of enzymes. The development of these production technologies has facilitated the generation of new enzyme-based products with applications in pharmaceuticals, food, bioactive peptides, and basic research studies, among others. The applicability of microorganisms in biotechnology is potentiated because of their various advantages, including large-scale production, short time of cultivation, and ease of handling. Currently, several studies are being conducted to search for new microbial peptidases with peculiar biochemical properties for industrial applications. Bioprospecting, being an important prerequisite for research and biotechnological development, is based on exploring the microbial diversity for enzyme production. Limited information is available on the production of specific proteolytic enzymes from bacterial and fungal species, especially on the subgroups threonine and glutamic peptidases, and the seventh catalytic type, nonhydrolytic asparagine peptide lyase. This gap in information motivated the present study about these unique biocatalysts. In this study, the biochemical and biotechnological aspects of the seven catalytic types of proteolytic enzymes, namely aspartyl, cysteine, serine, metallo, glutamic, and threonine peptidase, and asparagine peptide lyase, are summarized, with an emphasis on new studies, production, catalysis, and application of these enzymes.

  18. Recent advances in three-dimensional graphene based materials for catalysis applications. (United States)

    Qiu, Bocheng; Xing, Mingyang; Zhang, Jinlong


    Over the past few decades, two-dimensional graphene based materials (2DGMs) have piqued the interest of scientists worldwide, and the exploration of their potential applications in catalysis, sensors, electronic devices and energy storage due to their extraordinary physical and chemical properties has rapidly progressed. As for these 2DGMs, there is a complementary need to assemble 2D building blocks hierarchically into more complicated and hierarchical three-dimensional graphene-based materials (3DGMs). Such a capability is vitally crucial in order to design sophisticated and multi-functional catalysts with tailorable properties. This comprehensive review describes some important recent advances with respect to 3DGMs, including their preparation methods, characterization and applications in catalysis, e.g., photocatalysis, electrocatalysis, organic catalysis, and CO oxidation. The importance of the relationship between the structure and catalytic performance, a topic which has become a central focus of research in order to develop high-performance catalytic systems, is discussed. Likely future developments and their associated challenges are proposed and discussed.

  19. Impact of catalysis on the production of the top 50 US commodity chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Tonkovich, A.L.Y.


    Information on each chemical is stored in an accompanying Excel{trademark} 4.0 spreadsheet (``top5Ochem.xcl``). This analysis tool allows the user to make assumptions about process yield improvements and evaluate the corresponding impact on the process and feedstock energy. Many scenarios have been investigated and are reported in the text. If all of the catalytic processes associated with the top 50 chemicals were raised to their maximum process yields, the corresponding process and feedstock energy savings would exceed 0.47 quads per year. More realistic process yield improvements of 1%, 5%, and 10% where possible, would save 0.03, 0.14, and 0.23 quads per year. Many of the commodity chemicals face limitations from both the current catalyst and process. Catalysis is vital, but catalysis alone is not the answer to maximizing energy savings. Integration of catalysis development with process engineering research can lead to significant energy savings during the production of the top 50 chemicals.

  20. Ferroelectric based catalysis: Switchable surface chemistry (United States)

    Kakekhani, Arvin; Ismail-Beigi, Sohrab


    We describe a new class of catalysts that uses an epitaxial monolayer of a transition metal oxide on a ferroelectric substrate. The ferroelectric polarization switches the surface chemistry between strongly adsorptive and strongly desorptive regimes, circumventing difficulties encountered on non-switchable catalytic surfaces where the Sabatier principle dictates a moderate surface-molecule interaction strength. This method is general and can, in principle, be applied to many reactions, and for each case the choice of the transition oxide monolayer can be optimized. Here, as a specific example, we show how simultaneous NOx direct decomposition (into N2 and O2) and CO oxidation can be achieved efficiently on CrO2 terminated PbTiO3, while circumventing oxygen (and sulfur) poisoning issues. One should note that NOx direct decomposition has been an open challenge in automotive emission control industry. Our method can expand the range of catalytically active elements to those which are not conventionally considered for catalysis and which are more economical, e.g., Cr (for NOx direct decomposition and CO oxidation) instead of canonical precious metal catalysts. Primary support from Toyota Motor Engineering and Manufacturing, North America, Inc.

  1. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip > Dry Eye ... What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip Survival Tips ...

  2. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place to Begin Family & Friends ... Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place to Begin Family & Friends ...

  3. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... Trials – What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip > Dry ... Trials – What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip Survival ...

  4. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... here to find a place to begin. Sjögren’s Syndrome: A Place To Begin from Sjögren’s Syndrome Foundation on Vimeo . anxiety and buy , tranquility as well as medication © 2018 Sjögren's Syndrome Foundation, Inc. 10701 Parkridge Blvd. Suite 170, Reston, ...

  5. Tax Registers as a Tool for the Analysis of Wealth Inequalities in Selected Towns of the Polish-Lithuanian Commonwealth in the 17th Century and the beginning of the 18th Century. Overview and Research Problems

    Directory of Open Access Journals (Sweden)

    Katarzyna Wagner


    Full Text Available The article contains an analysis of tax registers from the 17th and the 18th century (municipal tax and Swedish contribution registers carried out to determine their usefulness for the research of wealth inequalities. Moreover, the paper defines factors determining wealth and discusses their usefulness in relation to tax registers.

  6. Surface-Enhanced Raman Spectroscopy for Heterogeneous Catalysis Research

    NARCIS (Netherlands)

    Harvey, C.E.


    Raman spectroscopy is valuable characterization technique for the chemical analysis of heterogeneous catalysts, both under ex-situ and in-situ conditions. The potential for Raman to shine light on the chemical bonds present in a sample makes the method highly desirable for detailed catalyst

  7. About the beginnings of orthopaedics in Timisoara. (United States)

    Poenaru, Dan V


    The historical and geographical territory of Banat is part of present-day Romania. Timisoara's history, the capital city of Banat region, dates back to the second century B.C. Medical life in Banat was re-organised after the promulgation of the Aulic Laws in the eighteenth century. Thorough research was undertaken through historic manuscripts, old newspapers, biographies and other papers about the history of Romanian medicine. The eighteenth century witnessed the building of three hospitals in Timisoara. In that period, Banat region benefited from the expertise and professionalism of doctors who graduated and were trained mainly in Central and Western European universities. By the beginning of the twentieth century, many medical clinics or sanatoriums specialising in orthopaedics and traumatology were offering their services to the population. Banat region had many good orthopaedists, and one of them was Prof. Dr. Doc. Berceanu, who graduated from the University of Medicine Bucharest and further specialised in Paris, France. He is the founder of the Orthopaedics and Traumatology Clinic in Timisoara.

  8. Creative Teaching: Why It Matters and where to Begin (United States)

    Rinkevich, Jennifer L.


    Current research indicates that creativity in teaching can and should be enhanced in order to promote student learning. This article begins by stressing the importance of creativity in education and the ways in which creative teaching benefits students. Next, it addresses key points for better understanding classroom creativity by identifying…

  9. LIVELIHOODS AND THE ECONOMY Prosperity begins with sound ...

    International Development Research Centre (IDRC) Digital Library (Canada)


    LIVELIHOODS AND THE ECONOMY Prosperity begins with sound economic policy and support for entrepreneurs. October 25, 2010. IDRC Communications. LASTING IMPACTS. IDRC's support for economic research has helped governments steer national economies toward growth, level the playing field for business, and ...

  10. Kinetic evolutionary behavior of catalysis-select migration

    International Nuclear Information System (INIS)

    Wu Yuan-Gang; Lin Zhen-Quan; Ke Jian-Hong


    We propose a catalysis-select migration driven evolution model of two-species (A- and B-species) aggregates, where one unit of species A migrates to species B under the catalysts of species C, while under the catalysts of species D the reaction will become one unit of species B migrating to species A. Meanwhile the catalyst aggregates of species C perform self-coagulation, as do the species D aggregates. We study this catalysis-select migration driven kinetic aggregation phenomena using the generalized Smoluchowski rate equation approach with C species catalysis-select migration rate kernel K(k;i,j) = Kkij and D species catalysis-select migration rate kernel J(k;i,j)= Jkij. The kinetic evolution behaviour is found to be dominated by the competition between the catalysis-select immigration and emigration, in which the competition is between JD 0 and KC 0 (D 0 and C 0 are the initial numbers of the monomers of species D and C, respectively). When JD 0 −KC 0 > 0, the aggregate size distribution of species A satisfies the conventional scaling form and that of species B satisfies a modified scaling form. And in the case of JD 0 −KC 0 0 −KC 0 > 0 case. (interdisciplinary physics and related areas of science and technology)

  11. Direct arylation and heterogeneous catalysis; ever the twain shall meet (United States)

    Cano, Rafael


    The formation of aryl–aryl bonds and heteroaryl analogues is one of the most important C–C bond forming processes in organic chemistry. Recently, a methodology termed Direct Arylation (DA) has emerged as an attractive alternative to traditional cross-coupling reactions (Suzuki–Miyaura, Stille, Negishi, etc.). A parallel focus of the pharmaceutical and other chemical industries has been on the use heterogeneous catalysis as a favourable substitute for its homogeneous counterpart in cross-coupling reactions. Only very recently has heterogeneous catalysis been proposed and applied, to DA reactions. In this perspective, we consider the terms ‘heterogeneous’ and ‘homogeneous’ and the problems associated with their delineation in transition-metal catalysed reactions. We highlight the reports at the interface of DA and heterogeneous catalysis and we comment briefly on the methods used which attempt to classify reaction types as homo- or heterogeneous. In future work we recommend an emphasis be placed on kinetic methods which provide an excellent platform for analysis. In addition two analytical techniques are described which if developed to run in situ with DA reactions would illuminate our understanding of the catalysis. Overall, we provide an entry point, and bring together the mature, yet poorly-understood, subject of heterogeneous catalysis with the rapidly expanding area of DA, with a view towards the acceleration of catalyst design and the understanding of catalyst behaviour. PMID:28717441

  12. Beginning Programming with Java For Dummies

    CERN Document Server

    Burd, Barry


    One of the most popular beginning programming books, now fully updated Java is a popular language for beginning programmers, and earlier editions of this fun and friendly guide have helped thousands get started. Now fully revised to cover recent updates for Java 7.0, Beginning Programming with Java For Dummies, 3rd Edition is certain to put more first-time programmers and Java beginners on the road to Java mastery.Explores what goes into creating a program, putting the pieces together, dealing with standard programming challenges, debugging, and making the program work Offers new options for

  13. Generating carbyne equivalents with photoredox catalysis (United States)

    Wang, Zhaofeng; Herraiz, Ana G.; Del Hoyo, Ana M.; Suero, Marcos G.


    Carbon has the unique ability to bind four atoms and form stable tetravalent structures that are prevalent in nature. The lack of one or two valences leads to a set of species—carbocations, carbanions, radicals and carbenes—that is fundamental to our understanding of chemical reactivity. In contrast, the carbyne—a monovalent carbon with three non-bonded electrons—is a relatively unexplored reactive intermediate; the design of reactions involving a carbyne is limited by challenges associated with controlling its extreme reactivity and the lack of efficient sources. Given the innate ability of carbynes to form three new covalent bonds sequentially, we anticipated that a catalytic method of generating carbynes or related stabilized species would allow what we term an ‘assembly point’ disconnection approach for the construction of chiral centres. Here we describe a catalytic strategy that generates diazomethyl radicals as direct equivalents of carbyne species using visible-light photoredox catalysis. The ability of these carbyne equivalents to induce site-selective carbon–hydrogen bond cleavage in aromatic rings enables a useful diazomethylation reaction, which underpins sequencing control for the late-stage assembly-point functionalization of medically relevant agents. Our strategy provides an efficient route to libraries of potentially bioactive molecules through the installation of tailored chiral centres at carbon–hydrogen bonds, while complementing current translational late-stage functionalization processes. Furthermore, we exploit the dual radical and carbene character of the generated carbyne equivalent in the direct transformation of abundant chemical feedstocks into valuable chiral molecules.

  14. High-Spin Cobalt Hydrides for Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Patrick L. [Univ. of Rochester, NY (United States)


    Organometallic chemists have traditionally used catalysts with strong-field ligands that give low-spin complexes. However, complexes with a weak ligand field have weaker bonds and lower barriers to geometric changes, suggesting that they may lead to more rapid catalytic reactions. Developing our understanding of high-spin complexes requires the use of a broader range of spectroscopic techniques, but has the promise of changing the mechanism and/or selectivity of known catalytic reactions. These changes may enable the more efficient utilization of chemical resources. A special advantage of cobalt and iron catalysts is that the metals are more abundant and cheaper than those currently used for major industrial processes that convert unsaturated organic molecules and biofeedstocks into useful chemicals. This project specifically evaluated the potential of high-spin cobalt complexes for small-molecule reactions for bond rearrangement and cleavage reactions relevant to hydrocarbon transformations. We have learned that many of these reactions proceed through crossing to different spin states: for example, high-spin complexes can flip one electron spin to access a lower-energy reaction pathway for beta-hydride elimination. This reaction enables new, selective olefin isomerization catalysis. The high-spin cobalt complexes also cleave the C-O bond of CO2 and the C-F bonds of fluoroarenes. In each case, the detailed mechanism of the reaction has been determined. Importantly, we have discovered that the cobalt catalysts described here give distinctive selectivities that are better than known catalysts. These selectivities come from a synergy between supporting ligand design and electronic control of the spin-state crossing in the reactions.

  15. A Healthy Start Can Begin Now (United States)

    A healthy pregnancy begins before you ever become pregnant. Give yourself the best chance for a healthy pregnancy and healthy baby before you start down the road to motherhood. If you smoke, now’s a great time to quit.

  16. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... Syndrome: A Place To Begin from Sjögren’s Syndrome Foundation on Vimeo . anxiety and buy , tranquility as well as medication © 2018 Sjögren's Syndrome Foundation, Inc. 10701 ...

  17. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... you will hear from Sjögren’s experts about the causes, treatments and manifestations of Sjögren’s. From ... Syndrome: A Place To Begin from Sjögren’s Syndrome Foundation ...

  18. Pioneers - The Beginning of Danish Electronic Music

    DEFF Research Database (Denmark)

    Kristensen, Thomas Bjørnsten


    Anmeldelse af dobbelt-cd'en Pioneers - The Beginning of Danish Electronic Music, der dokumenterer de tidligste år af dansk elektronisk musiks historie fra 1960-1978. Udgivelsesdato: 29.10......Anmeldelse af dobbelt-cd'en Pioneers - The Beginning of Danish Electronic Music, der dokumenterer de tidligste år af dansk elektronisk musiks historie fra 1960-1978. Udgivelsesdato: 29.10...

  19. Pesquisa etnográfica: iniciando sua compreensão Investigación etnográfica: iniciando su comprensión Ethnographic research: beginning to comprehend it

    Directory of Open Access Journals (Sweden)

    Cristina Maria Garcia de Lima


    Full Text Available O presente estudo visa apresentar algumas considerações teóricas sobre a pesquisa etnográfica com o propósito de divulgar este tipo de investigação para a enfermagem. O texto apresenta definição de alguns autores, bem como aspectos metodológicos desta abordagem.Este estudio presenta algunas consideraciones teóricas sobre la investigación etnográfica, con el propósito de divulgar este tipo de investigación para enfermería. el texto contempla la definición de algunos autores, así como los aspectos metodológicos de este abordaje.This study aimed at presenting a number of theoretical considerations related to ethnographic investigation viewing the disclosing of that type of nursing research. This study shows the definitions provided by various authors is addition to the methodology aspects regarding this type of approach.

  20. New and future developments in catalysis activation of carbon dioxide

    CERN Document Server

    Suib, Steven L


    New and Future Developments in Catalysis is a package of books that compile the latest ideas concerning alternate and renewable energy sources and the role that catalysis plays in converting new renewable feedstock into biofuels and biochemicals. Both homogeneous and heterogeneous catalysts and catalytic processes will be discussed in a unified and comprehensive approach. There will be extensive cross-referencing within all volumes. This volume presents a complete picture of all carbon dioxide (CO2) sources, outlines the environmental concerns regarding CO2, and critica

  1. Helicenes with embedded phosphole units in enantioselective gold catalysis. (United States)

    Yavari, Keihann; Aillard, Paul; Zhang, Yang; Nuter, Frédérick; Retailleau, Pascal; Voituriez, Arnaud; Marinetti, Angela


    This paper discloses the first uses of phosphahelicenes as chiral ligands in transition-metal catalysis. Unlike all known helical phosphines used so far in catalysis, the phosphorus function of phosphahelicenes is embedded in the helical structure itself. This crucial structural feature originates unprecedented catalytic behaviors and efficiency. An appropriate design and fine tuning allowed both high catalytic activity and good enantiomeric excesses to be attained in the gold promoted cycloisomerizations of N-tethered 1,6-enynes and dien-ynes. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Mechanistic Studies on ADAMTS13 Catalysis (United States)

    Di Stasio, Enrico; Lancellotti, Stefano; Peyvandi, Flora; Palla, Roberta; Mannucci, Pier Mannuccio; De Cristofaro, Raimondo


    The zinc-protease a disintegrin-like and metalloprotease with thrombospondin type I repeats (ADAMTS13) cleaves the Tyr1605-Met1606 peptide bond of von Willebrand factor (VWF), avoiding the accumulation of ultra large VWF multimers. Hydrolysis by ADAMTS13 of a VWF analog (Asp1596-Arg1668 peptide, fluorescence energy transfer substrate [FRETS]-VWF73) was investigated by a fluorescence quenching method (FRETS method) from 15°C to 45°C and pH values from 4.5 to 10.5. The catalysis was influenced by two ionizable groups, whose pKa values were equal to 6.41 ± 0.08 (ionization enthalpy = 32.6 ± 1.7 kJ/mol) and 4 ± 0.1 (ionization enthalpy = 3.8 ± 0.4 kJ/mol), whereas these values were equal to 6 ± 0.1 and 4.1 ± 0.1, respectively, in Co2+-substituted ADAMTS13. The catalytic process of FRETS-VWF73 hydrolysis showed negative activation entropy (−144 kJ/mol), suggesting that the transition state becomes more ordered than the ground state of the reactants. The kcat/Km values were not linearly correlated with temperature, as expression of change of the kinetic “stickiness” of the substrate. The Met1606-Arg1668 peptide product acted as hyperbolic mixed-type inhibitor of FRETS-VWF73 hydrolysis. Asp1653, Glu1655, Glu1660, Asp1663, together with the hydrophilic side chain of Thr1656 were shown to form a “hot spot” in the VWF A2 sequence, which drives the molecular recognition and allosteric regulation of binding to ADAMTS13. The interaction of the Met1606-Arg1668 region of VWF with ADAMTS13 involves basic residues of the protease and is thus progressively inhibited at pH values >8.50. A molecular model of the FRETS-VWF73 showed that the substrate can fit into the active site only if ADAMTS13 assumes a C-like shape and, interacting with the acidic 1653–1668 region of VWF, properly orients the Tyr1605-Met1606 peptide bond for the cleavage by the zinc-aquo complex in the active site. PMID:18502798

  3. Negative-Ion Catalysis of Methane to Methanol without CO2 Emission (United States)

    Tesfamichael, A.; Suggs, K.; Felfli, Z.; Msezane, A. Z.


    We have carried out a theoretical investigation of the catalytic activities of the atomic Y-, Ru-, At-, In-, Pd-, Ag-, Os- and Pt- ions for the selective partial oxidation of methane to methanol without CO2 emission. The objective was to identify effective atomic negative ion catalysts using the data for the atomic Au- ion as the benchmark. The role of the atomic negative ions in catalysis is essentially to disrupt the C-H bonding in CH4 oxidation thereby eliminate the competition from the carbon dioxide formation. Dispersion-corrected density-functional theory has been used for the investigation. From the energy barrier calculations and the thermodynamics of the reactions, we conclude that the catalytic effect of the atomic Ag-, At-, Ru-, and Os- ions is higher than that of the atomic Au- ion catalysis of CH4 conversion to methanol. By controlling the temperature around 290, 300, 310, 320 and 325 K methane can be completely oxidized to methanol without the emission of the CO2 through the atomic Os-, Ag-, At-, Ru- and Au- ion catalysts, respectively. We conclude by recommending the investigation of the catalytic activities of combinations of the above negative ions for significant enhancement of the selective partial oxidation of methane to methanol. Research supported by Army Research Office (Grant W911NF-11-1-0194); the US DOE, Division of Chemical Sciences, Office of Basic Energy Sciences, Office of Energy Research and AFOSR (Grants FA9550-10-1-0254).

  4. New Ir Bis-Carbonyl Precursor for Water Oxidation Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Daria L. [Department of Chemistry, Yale University, 225; Beltrán-Suito, Rodrigo [Department of Chemistry, Yale University, 225; Thomsen, Julianne M. [Department of Chemistry, Yale University, 225; Hashmi, Sara M. [Department of Chemical and Environmental; Materna, Kelly L. [Department of Chemistry, Yale University, 225; Sheehan, Stafford W. [Catalytic Innovations LLC, 70 Crandall; Mercado, Brandon Q. [Department of Chemistry, Yale University, 225; Brudvig, Gary W. [Department of Chemistry, Yale University, 225; Crabtree, Robert H. [Department of Chemistry, Yale University, 225


    This paper introduces IrI(CO)2(pyalc) (pyalc = (2-pyridyl)-2-propanoate) as an atom-efficient precursor for Ir-based homogeneous oxidation catalysis. This compound was chosen to simplify analysis of the water oxidation catalyst species formed by the previously reported Cp*IrIII(pyalc)OH water oxidation precatalyst. Here, we present a comparative study on the chemical and catalytic properties of these two precursors. Previous studies show that oxidative activation of Cp*Ir-based precursors with NaIO4 results in formation of a blue IrIV species. This activation is concomitant with the loss of the placeholder Cp* ligand which oxidatively degrades to form acetic acid, iodate, and other obligatory byproducts. The activation process requires substantial amounts of primary oxidant, and the degradation products complicate analysis of the resulting IrIV species. The species formed from oxidation of the Ir(CO)2(pyalc) precursor, on the other hand, lacks these degradation products (the CO ligands are easily lost upon oxidation) which allows for more detailed examination of the resulting Ir(pyalc) active species both catalytically and spectroscopically, although complete structural analysis is still elusive. Once Ir(CO)2(pyalc) is activated, the system requires acetic acid or acetate to prevent the formation of nanoparticles. Investigation of the activated bis-carbonyl complex also suggests several Ir(pyalc) isomers may exist in solution. By 1H NMR, activated Ir(CO)2(pyalc) has fewer isomers than activated Cp*Ir complexes, allowing for advanced characterization. Future research in this direction is expected to contribute to a better structural understanding of the active species. A diol crystallization agent was needed for the structure determination of 3.

  5. Aquinas and Contemporary Cosmology: Creation and Beginnings (United States)

    Carroll, William E.

    Discussions in the Middle Ages about creation and the temporal beginning of the world involved sophisticated analyses in theology, metaphysics, and natural philosophy. Mediaeval insights on this subject, especially Thomas Aquinas' defense of the intelligibility of an eternal, created universe, can help to clarify reflections about the philosophical and theological implications of contemporary cosmological theories: from the "singularity" of the Big Bang, to "quantum tunneling from nothing," to multiverse scenarios. Thomas' insights help us to see the value of Georges Lemaître's insistence that his cosmological reflections must be kept separate from an analysis of creation. This essay will look at different senses of "beginning" and examine the claim that creation, in its fundamental meaning, tells us nothing about whether there is a temporal beginning to the universe. Multiverse models, like that recently proposed by Stephen Hawking and Leonard Mlodinow, may challenge certain views of a Grand Designer, but not of a Creator.

  6. Ivor Horton's beginning visual C++ 2013

    CERN Document Server

    Horton, Ivor


    Learn C++ with the best tutorial on the market! Horton's unique tutorial approach and step-by-step guidance have helped over 100,000 novice programmers learn C++. In Ivor Horton's Beginning Visual C++ 2013, Horton not only guides you through the fundamentals of the standard C++ language, but also teaches you how C++ is used in the latest Visual Studio 2013 environment. Visual Studio 2013 includes major changes to the IDE and expanded options for C++ coding. Ivor Horton's Beginning Visual C++ 2013 will teach you the latest techniques to take your Visual C++ coding to an all-new level.C++ langua

  7. Beginning Microsoft SQL Server 2012 Programming

    CERN Document Server

    Atkinson, Paul


    Get up to speed on the extensive changes to the newest release of Microsoft SQL Server The 2012 release of Microsoft SQL Server changes how you develop applications for SQL Server. With this comprehensive resource, SQL Server authority Robert Vieira presents the fundamentals of database design and SQL concepts, and then shows you how to apply these concepts using the updated SQL Server. Publishing time and date with the 2012 release, Beginning Microsoft SQL Server 2012 Programming begins with a quick overview of database design basics and the SQL query language and then quickly proceeds to sho

  8. Beginning iPad Application Development

    CERN Document Server

    Lee, Wei-Meng


    A hands-on approach to iPad application development. Beginning iPad Application Development is written to help jumpstart beginning iPad developers. It covers the various topics in such a manner that you will progressively learn without being overwhelmed by the details. It adopts the philosophy that the best way to learn is by doing, hence the numerous Try It Out sections in all the chapters, which first show you how to build something and then explain how things work. Although iPad programming is a huge topic, the aim for this book is to get you started with the fundamentals, and help you unde

  9. An effective modular process for biodiesel manufacturing using heterogeneous catalysis

    NARCIS (Netherlands)

    Dimian, A.C.; Rothenberg, G.


    We present an innovative reaction set-up and process for biodiesel manufacturing by heterogeneous catalysis. This process has two key advantages over the state-of-the-art process: it enables a variable reaction time and easy catalyst switching/replacement. The process principle presented here is

  10. Two-dimensional zeolites in catalysis: current status and perspectives

    Czech Academy of Sciences Publication Activity Database

    Opanasenko, Maksym; Roth, Wieslaw Jerzy; Čejka, Jiří


    Roč. 6, č. 8 (2016), s. 2467-2484 ISSN 2044-4753 R&D Projects: GA ČR GP13-17593P; GA ČR(CZ) GAP106/12/0189 Institutional support: RVO:61388955 Keywords : mesoporous molecular sieves * catalysis * acylation reactions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.773, year: 2016

  11. Role of catalysis in sustainable production of synthetic elastomers

    Indian Academy of Sciences (India)

    butadiene helped to produce synthetic polybutadiene rubber (BR) and the advent of Ziegler–Natta (Z-N) catalysis later played a key role in sustenance of PBR ..... butadiene in a batch reactor using a commercially used catalytic system (Co octoate/Et2AlCl/water).10 The sup- ported cobalt-based catalyst was also reported to ...

  12. Synergy between experimental and computational approaches to homogeneous photoredox catalysis. (United States)

    Demissie, Taye B; Hansen, Jørn H


    In this Frontiers article, we highlight how state-of-the-art density functional theory calculations can contribute to the field of homogeneous photoredox catalysis. We discuss challenges in the fields and potential solutions to be found at the interface between theory and experiment. The exciting opportunities and insights that can arise through such an interdisciplinary approach are highlighted.

  13. Alkylation of hydrothiophosphoryl compounds in conditions of interphase catalysis

    International Nuclear Information System (INIS)

    Aladzheva, I.M.; Odinets, I.L.; Petrovskij, P.V.; Mastryukova, T.A.; Kabachkin, M.I.


    A method of interphase catalysis permitted to develop a common method for synthesis of compounds with thiophosphoryl group. The effect of nature of hydrothiophosphoryl compound, alkylating agent, two-phase system and reaction conditions on alkylation product yields was investigated in detail

  14. Optically understanding the dependence of catalysis kinetics on ...

    Indian Academy of Sciences (India)

    DOI 10.1007/s12034-017-1364-6. Optically understanding the dependence of catalysis kinetics on work function of nanocatalyst. HENAM SYLVIA DEVI, THIYAM DAVID SINGH and HENAM PREMANANDA SINGH. ∗. Department of Basic Sciences and Humanities, National Institute of Technology, Imphal 795001, India.

  15. Counterion Binding Effects on the Micellar Catalysis of the Base ...

    African Journals Online (AJOL)

    The effects of counterion binding on micellar catalysis of the base hydrolysis of FE(phen) has been investaged. Pseudo first order rate constant, k , incrases with increase in the concentrations of ME NCI and (But) NC1 at any fixed Sodium dodecyl sulphate (SDS) concentration while the reserve is the case with NH CL.

  16. Robustness of the rotary catalysis mechanism of F1-ATPase. (United States)

    Watanabe, Rikiya; Matsukage, Yuki; Yukawa, Ayako; Tabata, Kazuhito V; Noji, Hiroyuki


    F1-ATPase (F1) is the rotary motor protein fueled by ATP hydrolysis. Previous studies have suggested that three charged residues are indispensable for catalysis of F1 as follows: the P-loop lysine in the phosphate-binding loop, GXXXXGK(T/S); a glutamic acid that activates water molecules for nucleophilic attack on the γ-phosphate of ATP (general base); and an arginine directly contacting the γ-phosphate (arginine finger). These residues are well conserved among P-loop NTPases. In this study, we investigated the role of these charged residues in catalysis and torque generation by analyzing alanine-substituted mutants in the single-molecule rotation assay. Surprisingly, all mutants continuously drove rotary motion, even though the rotational velocity was at least 100,000 times slower than that of wild type. Thus, although these charged residues contribute to highly efficient catalysis, they are not indispensable to chemo-mechanical energy coupling, and the rotary catalysis mechanism of F1 is far more robust than previously thought. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Heterogeneous Catalysis: On Bathroom Mirrors and Boiling Stones (United States)

    Philipse, Albert P.


    Though heterogeneous nucleation of liquid droplets on a smooth surface (such as a bathroom mirror) is a classical topic in nucleation theory, it is not well-known that this topic is actually a pedagogical example of heterogeneous catalysis: the one and only effect of the surface is to lower the activation Gibbs energy of droplet formation. In…

  18. Towards a generic model of catalysis | Grayson | Bulletin of the ...

    African Journals Online (AJOL)

    We consider polarizabilities and hardness/softness parameters to see how local polarizations of the electron density may also be responsible for activation of a localised area of a large molecule. KEY WORDS: Electrostatic catalysis, Geometrical strain, Environment strain, Entasis, Polarizability, Hardness and softness. Bull.

  19. Catalysis of the electrochemical water oxidation to oxygen

    NARCIS (Netherlands)

    Díaz Morales, Oscar Alfonso


    This thesis discusses the parameters affecting the catalysis for the electrochemical conversion of water into oxygen. The slow kinetics for the oxygen evolution reaction (OER) is one of the major bottlenecks in the solar energy-to-fuels conversion process, which reduces the efficiency for the

  20. Magnetic Catalysis of Chiral Symmetry Breaking: A Holographic Prospective

    Directory of Open Access Journals (Sweden)

    Veselin Filev


    Zeeman splitting of the energy levels, and the existence of pseudo, Goldstone modes. An analytic derivation of the Gell-Mann-Oaks-Renner relation for the D3/D7 set up is reviewed. In the D3/D5 case, the pseudo-Goldstone modes satisfy nonrelativistic dispersion relation. The studies reviewed confirm the universal nature of the magnetic catalysis of mass generation.

  1. New access to trisubstituted 3-pyrrolines under phosphine catalysis. (United States)

    Schuler, Marie; Duvvuru, Deepti; Retailleau, Pascal; Betzer, Jean-François; Marinetti, Angela


    Conjugated dienes, properly activated by electron-withdrawing groups on both ends, are shown to be suitable substrates for phosphine-promoted organocatalytic processes. Their reactions with imines, under phosphine catalysis, afford a new and efficient synthetic approach to functionalized 3-pyrrolines.

  2. Examining the role of glutamic acid 183 in chloroperoxidase catalysis

    NARCIS (Netherlands)

    Yi, X.; Conesa, A.; Punt, P.J.; Hager, L.P.


    Site-directed mutagenesis has been used to investigate the role of glutamic acid 183 in chloroperoxidase catalysis. Based on the x-ray crystallographic structure of chloroperoxidase, Glu-183 is postulated to function on distal side of the heme prosthetic group as an acid-base catalyst in


    African Journals Online (AJOL)


    Chemical concepts are applied without direct .... Towards a generic model of catalysis. Bull. Chem. Soc. Ethiop. 2008, 22(3). 435 equilibrium must have an energy greater than the equilibrium, so it is possible that certain catalytic ... There exists a wealth of literature that has relevance to this problem, that all attack it from a.

  4. Sustainable Catalysis_Energy efficient reactions and Applications (United States)

    This book chapter discusses various catalysts for environmental remediation. Detailed information on catalysis using ferrate and ferrite oxidation, TiO2 photocatalysis, and new catalysts (i.e., graphene, perovskites and graphitic carbon nitride) is provided for the degradation of...

  5. Role of catalysis in sustainable production of synthetic elastomers

    Indian Academy of Sciences (India)

    significant role in the sustainable development of elastomers with special reference to polybutadiene rubber. Keywords. Elastomers; catalysis; tyres and ... polymer known to mankind and its first use was as an eraser.1 Apparently, the name ... and sticky depending upon the environmental condi- tions. Charles Goodyear,1 ...

  6. Integration of heterogeneous and biochemical catalysis for production of fuels and chemicals from biomass. (United States)

    Wheeldon, Ian; Christopher, Phillip; Blanch, Harvey


    The past decade has seen significant government and private investment in fundamental research and process development for the production of biofuels and chemicals from lignocellulosic biomass-derived sugars. This investment has helped create new metabolic engineering and synthetic biology approaches, novel homogeneous and heterogeneous catalysts, and chemical and biological routes that convert sugars, lignin, and waste products such as glycerol into hydrocarbon fuels and valuable chemicals. With the exception of ethanol, economical biofuels processes have yet to be realized. A potentially viable way forward is the integration of biological and chemical catalysis into processes that exploit the inherent advantages of each technology while circumventing their disadvantages. Microbial fermentation excels at converting sugars from low-cost raw materials streams into simple alcohols, acids, and other reactive intermediates that can be condensed into highly reduced, long and branched chain hydrocarbons and other industrially useful compounds. Chemical catalysis most often requires clean feed streams to avoid catalyst deactivation, but the chemical and petroleum industries have developed large scale processes for C-C coupling, hydrogenation, and deoxygenation that are driven by low grade heat and low-cost feeds such as hydrogen derived from natural gas. In this context, we suggest that there is a reasonably clear route to the high yield synthesis of biofuels from biomass- or otherwise derived-fermentable sugars: the microbial production of reactive intermediates that can be extracted or separated into clean feed stream for upgrading by chemical catalysis. When coupled with new metabolic engineering strategies that maximize carbon and energy yields during fermentation, biomass-to-fuels processes may yet be realized. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Asymmetric catalysis in Brazil: development and potential for advancement of Brazilian chemical industry

    International Nuclear Information System (INIS)

    Braga, Antonio Luiz; Luedtke, Diogo Seibert; Schneider, Paulo Henrique; Andrade, Leandro Helgueira; Paixao, Marcio Weber


    The preparation of enantiomerically pure or enriched substances is of fundamental importance to pharmaceutical, food, agrochemical, and cosmetics industries and involves a growing market of hundreds of billions of dollars. However, most chemical processes used for their production are not environmentally friendly because in most cases, stoichiometric amounts of chiral inductors are used and substantial waste is produced. In this context, asymmetric catalysis has emerged as an efficient tool for the synthesis of enantiomerically enriched compounds using chiral catalysts. More specifically, considering the current scenario in the Brazilian chemical industry, especially that of pharmaceuticals, the immediate prospect for the use of synthetic routes developed in Brazil in an enantioselective fashion or even the discovery of new drugs is practically null. Currently, the industrial production of drugs in Brazil is primarily focused on the production of generic drugs and is basically supported by imports of intermediates from China and India. In order to change this panorama and move forward toward the gradual incorporation of genuinely Brazilian synthetic routes, strong incentive policies, especially those related to continuous funding, will be needed. These incentives could be a breakthrough once we establish several research groups working in the area of organic synthesis and on the development and application of chiral organocatalysts and ligands in asymmetric catalysis, thus contributing to boost the development of the Brazilian chemical industry. Considering these circumstances, Brazil can benefit from this opportunity because we have a wide biodiversity and a large pool of natural resources that can be used as starting materials for the production of new chiral catalysts and are creating competence in asymmetric catalysis and related areas. This may decisively contribute to the growth of chemistry in our country. (author)

  8. Excess mutual catalysis is required for effective evolvability. (United States)

    Markovitch, Omer; Lancet, Doron


    It is widely accepted that autocatalysis constitutes a crucial facet of effective replication and evolution (e.g., in Eigen's hypercycle model). Other models for early evolution (e.g., by Dyson, Gánti, Varela, and Kauffman) invoke catalytic networks, where cross-catalysis is more apparent. A key question is how the balance between auto- (self-) and cross- (mutual) catalysis shapes the behavior of model evolving systems. This is investigated using the graded autocatalysis replication domain (GARD) model, previously shown to capture essential features of reproduction, mutation, and evolution in compositional molecular assemblies. We have performed numerical simulations of an ensemble of GARD networks, each with a different set of lognormally distributed catalytic values. We asked what is the influence of the catalytic content of such networks on beneficial evolution. Importantly, a clear trend was observed, wherein only networks with high mutual catalysis propensity (p(mc)) allowed for an augmented diversity of composomes, quasi-stationary compositions that exhibit high replication fidelity. We have reexamined a recent analysis that showed meager selection in a single GARD instance and for a few nonstationary target compositions. In contrast, when we focused here on compotypes (clusters of composomes) as targets for selection in populations of compositional assemblies, appreciable selection response was observed for a large portion of the networks simulated. Further, stronger selection response was seen for high p(mc) values. Our simulations thus demonstrate that GARD can help analyze important facets of evolving systems, and indicate that excess mutual catalysis over self-catalysis is likely to be important for the emergence of molecular systems capable of evolutionlike behavior.

  9. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... the SSF Blog: Conquering Sjögren’s SSF Social Network Host an SSF Event SSF Store - Books, CDs & More ... Trials – What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip Survival ...

  10. Symposium: A Beginning in the Humanities (United States)

    Brooks, Peter; Fry, Paul H.; Carnochan, W. B.; Culler, Jonathan; Lerer, Seth; Marshall, Donald G.; Johnson, Barbara; Steiner, Wendy; Haack, Susan; Nussbaum, Martha C.


    2001 marked Yale's 300th birthday. It seemed an opportunity for reflection on the evolution of the institution, and particularly on the vicissitudes of the humanities over those three centuries. This article presents essays which represent a selection from the symposium, "Beginning With the Humanities," held at the Whitney Humanities Center on…

  11. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip > Dry Eye Tips > Dry Mouth Tips > Other Dryness Tips > Diet & Food Tips > Peripheral Neuropathy Tips > Surgery Tips Survival Tips ...

  12. The Beginnings of X-ray Crystallography

    Indian Academy of Sciences (India)

    IAS Admin

    The Beginnings of X-ray Crystallography. A Profile on the Two Braggs. Those were the days when Science was hovering around the wave–particle duality. William. Henry Bragg was toying with the idea that X-rays are particles and the observation made by Max von Laue that X-rays are diffracted by crystals could indeed ...

  13. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip > Dry Eye ... Team Sjögren’s Running Program National Patient Conference Shop Online to Support the SSF Blog: Conquering Sjögren’s SSF ...




  15. Sjogren's Syndrome: A Place to Begin

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    Full Text Available ... of Sjögren's Living with Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place to Begin Family & ... Patient Information Living with Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place ...

  16. Sjogren's Syndrome: A Place to Begin

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    Full Text Available ... Dry Eyes >> Resources > Dry Mouth Diagnosis Treatments Patient Information Faces of Sjögren's Living with Sjögren's Survey Sjögren’s ... Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip > Dry Eye Tips > ...

  17. Sjogren's Syndrome: A Place to Begin

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    Full Text Available ... with Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place to Begin Family & Friends Information Sjögren’s FAQs Glossary Sjögren’s Tip > Dry Eye Tips > Dry Mouth Tips > Other Dryness Tips > Diet & Food Tips > Peripheral ...

  18. The "White Canvas" Approach to Beginning Conducting. (United States)

    Mailman, Matthew


    Discusses the white canvas approach to beginning conducting, a basic mirror conducting of both hands generating the symmetrical takt, or beat, that represents the basic foundation of conducting. Focuses on such issues as conducting as communication, conducting at the tip of the baton, and extension beyond the white canvas approach. (CMK)

  19. Patterns of Analogical Reasoning among Beginning Readers (United States)

    Farrington-Flint, Lee; Wood, Clare; Canobi, Katherine H.; Faulkner, Dorothy


    Despite compelling evidence that analogy skills are available to beginning readers, few studies have actually explored the possibility of identifying individual differences in young children's analogy skills in early reading. The present study examined individual differences in children's use of orthographic and phonological relations between…

  20. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... who care about them. Home > About Sjögren's When a person is diagnosed with Sjögren’s, they often don' ... Sjögren’s. From there, we hope you will have a place to begin as you develop a partnership ...

  1. An ENSO beginning in the year 2000?

    Digital Repository Service at National Institute of Oceanography (India)

    Gopinathan, C.K.

    Several models have been developed over the last few decades to predict the advent of new ENSO events several months in advance of the actual event. None of the models have predicted a warm event beginning by the year 2000. Positive SST anomalies...

  2. On New Beginnings and Democratic Legitimacy

    Directory of Open Access Journals (Sweden)

    Signe Larsen


    Full Text Available This paper sets out to discuss the enigma of revolutionary new political beginnings of constitutional orders. The problem is that when a political community is constituted, the act of constituting per definition is unconstitutional or extra-legal. For this reason the question of new beginnings is a political and not a legal question. The question of what the authority of the constituent act is presents an important question since the constitution is the fundamental law from which the legitimacy or authority of all other laws is derived. The problem for this paper is whether and in what way it is possible to think new beginnings that are not merely institutionalizations of factual relations of domination or arbitrary acts of violence. This problem is discussed on basis of two revolutionary theories in the tradition of constituent power—Emmanuel Sieyès and Hannah Arendt—that both understand power to emanate from below and not from above whereby they both, though in different way, present arguments against the understanding that new beginnings merely are institutionalizations of relations of domination and arbitrary acts of violence. The question of whether and to what extent they are successful and whether their theories are democratic will finally be discussed.

  3. Helicene-Based Phosphite Ligands in Asymmetric Transition-Metal Catalysis: Exploring Rh-Catalyzed Hydroformylation and Ir-Catalyzed Allylic Amination

    Czech Academy of Sciences Publication Activity Database

    Krausová, Zuzana; Sehnal, Petr; Bondzic, B. P.; Chercheja, S.; Eilbracht, P.; Stará, Irena G.; Šaman, David; Starý, Ivo

    -, 20/21 (2011), s. 3849-3857 ISSN 1434-193X R&D Projects: GA ČR GA203/09/1766; GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : asymmetric catalysis * helical structures * P ligands * hydroformylation * amination Subject RIV: CC - Organic Chemistry Impact factor: 3.329, year: 2011

  4. Versatile cooperative ligand effects in group 9 transition metal catalysis: Applications in transfer hydrogenation & hydrogen autotransfer reactions, ketene & ketene imine synthesis and hydroformylation

    NARCIS (Netherlands)

    Tang, Z.


    Cooperative ligand effects of transition metal complexes have a profound impact on the reaction outcome of catalytic reactions, and development of (new) cooperative metal-ligand systems is a hot topic in current catalysis research. Conventional ligands with hydride-accepting/delivering activities

  5. Iron Catalysis in Organic Synthesis: A Critical Assessment of What It Takes To Make This Base Metal a Multitasking Champion (United States)


    The current status of homogeneous iron catalysis in organic chemistry is contemplated, as are the reasons why this particular research area only recently starts challenging the enduring dominance of the late and mostly noble metals over the field. Centered in the middle of the d-block and able to support formal oxidation states ranging from −II to +VI, iron catalysts hold the promise of being able to encompass organic synthesis at large. They are expected to serve reductive as well as oxidative regimes, can emulate “noble tasks”, but are also able to adopt “early” transition metal character. Since a comprehensive coverage of this multidimensional agenda is beyond the scope of an Outlook anyway, emphasis is laid in this article on the analysis of the factors that perhaps allow one to control the multifarious chemical nature of this earth-abundant metal. The challenges are significant, not least at the analytical frontier; their mastery mandates a mindset that differs from the routines that most organic chemists interested in (noble metal) catalysis tend to cultivate. This aspect notwithstanding, it is safe to predict that homogeneous iron catalysis bears the chance to enable a responsible paradigm for chemical synthesis and a sustained catalyst economy, while potentially providing substantial economic advantages. This promise will spur the systematic and in-depth investigations that it takes to upgrade this research area to strategy-level status in organic chemistry and beyond. PMID:27981231

  6. LDRD 2013 Annual Report: Laboratory Directed Research and Development Program Activities

    Energy Technology Data Exchange (ETDEWEB)

    Bookless, W. [Brookhaven National Lab. (BNL), Upton, NY (United States)


    This LDRD project establishes a research program led by Jingguang Chen, who has started a new position as a Joint Appointee between BNL and Columbia University as of FY2013. Under this project, Dr. Chen will establish a new program in catalysis science at BNL and Columbia University. The LDRD program will provide initial research funding to start research at both BNL and Columbia. At BNL, Dr. Chen will initiate laboratory research, including hiring research staff, and will collaborate with the existing BNL catalysis and electrocatalysis research groups. At Columbia, a subcontract to Dr. Chen will provide startup funding for his laboratory research, including initial graduate student costs. The research efforts will be linked under a common Catalysis Program in Sustainable Fuels. The overall impact of this project will be to strengthen the BNL catalysis science program through new linked research thrusts and the addition of an internationally distinguished catalysis scientist.

  7. Perspectives on electrostatics and conformational motions in enzyme catalysis. (United States)

    Hanoian, Philip; Liu, C Tony; Hammes-Schiffer, Sharon; Benkovic, Stephen


    CONSPECTUS: Enzymes are essential for all living organisms, and their effectiveness as chemical catalysts has driven more than a half century of research seeking to understand the enormous rate enhancements they provide. Nevertheless, a complete understanding of the factors that govern the rate enhancements and selectivities of enzymes remains elusive, due to the extraordinary complexity and cooperativity that are the hallmarks of these biomolecules. We have used a combination of site-directed mutagenesis, pre-steady-state kinetics, X-ray crystallography, nuclear magnetic resonance (NMR), vibrational and fluorescence spectroscopies, resonance energy transfer, and computer simulations to study the implications of conformational motions and electrostatic interactions on enzyme catalysis in the enzyme dihydrofolate reductase (DHFR). We have demonstrated that modest equilibrium conformational changes are functionally related to the hydride transfer reaction. Results obtained for mutant DHFRs illustrated that reductions in hydride transfer rates are correlated with altered conformational motions, and analysis of the evolutionary history of DHFR indicated that mutations appear to have occurred to preserve both the hydride transfer rate and the associated conformational changes. More recent results suggested that differences in local electrostatic environments contribute to finely tuning the substrate pKa in the initial protonation step. Using a combination of primary and solvent kinetic isotope effects, we demonstrated that the reaction mechanism is consistent across a broad pH range, and computer simulations suggested that deprotonation of the active site Tyr100 may play a crucial role in substrate protonation at high pH. Site-specific incorporation of vibrational thiocyanate probes into the ecDHFR active site provided an experimental tool for interrogating these microenvironments and for investigating changes in electrostatics along the DHFR catalytic cycle

  8. Beginning science teachers' performances: Assessment in times of reform (United States)

    Budzinsky, Fie K.


    The current reform in science education and the research on effective teaching and student learning have reinforced the importance of teacher competency. To better measure performances in the teaching of science, performance assessment has been added to Connecticut's licensure process for beginning science teachers. Teaching portfolios are used to document teaching and learning over time. Portfolios, however, are not without problems. One of the major concerns with the portfolio assessment process is its subjectivity. Assessors may not have opportunities to ask clarifying or follow-up questions to enhance the interpretation of a teacher's performance. In addition, portfolios often contain components based on self-documentation, which are subjective. Furthermore, the use of portfolios raises test equity issues. These concerns present challenges for persons in charge of establishing the validity of a portfolio-based licensure process. In high-stakes decision processes, such as teaching licensure, the validity of the assessment instruments must be studied. The primary purpose of this study was to explore the criterion-related validity of the Connecticut State Department of Education's Beginning Science Teaching Portfolio by comparing the interpretations of performances from science teaching portfolios to those derived from another assessment method, the Expert Science Teaching Educational and Evaluation Model, (ESTEEM). The analysis of correlations between the Beginning Science Teaching Portfolio and ESTEEM instrument scores was the primary method for establishing support for validity. The results indicated moderate correlations between all Beginning Science Teaching Portfolio and ESTEEM category and total variables. Multiple regression was used to examine whether differences existed in beginning science teachers' performances based on gender, poverty group, school level, and science discipline taught. None of these variables significantly contributed to the

  9. [Dementia. Most frequent forms of beginning]. (United States)

    Arizaga, Raúl L; Cristalli, Diana O; Golimstok, Angel; Saredo, Gustavo


    In the present chapter, that is part of a more comprehensive work performed by the Argentine Consortium for Dementia Study - Consortium Argentino para el Estudio de la Demencia (CAED), we describe the most frequent forms of beginning for the four more prevalent types of dementia: Alzheimer's disease, dementia with Lewy bodies, vascular dementia and frontotemporal dementia). Despite this, it must be kept in mind, that frequently the clinical presentation is not typical and the diagnostic impression at the disease's beginning is controversial comparing it with the etiological diagnosis reached when the dementia is definitively installed. This issue must be considered when the initial impression is given to the patient and/or relatives. It must be clarified, in this instance, that this impression is based in statistical data of ways of presentation, but the definitive diagnosis could be different according to the dementia evolution.

  10. Beginning at the beginning: Recall order and the number of words to be recalled. (United States)

    Tan, Lydia; Ward, Geoff; Paulauskaite, Laura; Markou, Maria


    When participants are asked to recall a short list of words in any order that they like, they tend to initiate recall with the first list item and proceed in forward order, even when this is not a task requirement. The current research examined whether this tendency might be influenced by varying the number of items that are to be recalled. In 3 experiments, participants were presented with short lists of between 4 and 6 words and instructed to recall 1, 2, 3, or all of the items from the lists. Data were collected using immediate free recall (IFR, Experiment 1), immediate serial recall (ISR, Experiment 2), and a variant of ISR that we call ISR-free (Experiment 3), in which participants had to recall words in their correct serial positions but were free to output the words in any order. For all 3 tasks, the tendency to begin recall with the first list item occurred only when participants were required to recall as many items from the list as they could. When participants were asked to recall only 1 or 2 items, they tended to initiate recall with end-of-list items. It is argued that these findings show for the first time a manipulation that eliminates the initial tendency to recall in forward order, provide some support for recency-based accounts of IFR and help explain differences between single-response and multiple-response immediate memory tasks. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  11. Radiotherapy in veterinary medicine: beginnings and perspectives

    International Nuclear Information System (INIS)

    Fernandes, Marco A.R.; Andrade, Alexandre L.; Luvizoto, Maria C.R.; Piero, Juliana R.; Ciarlini, Luciana D.R.P.


    This work presents a brief historical about the use of ionizing radiations in Veterinary Medicine, instructing the physical beginnings and techniques wrapped in the realization of the proceedings of radiotherapy in animals, illustrating some treated cases, highlighting the difficulties and pointing to the perspectives and importance of the acting of the medical physics in this kind of therapeutic still little used in the national scenery. (author)

  12. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... Faces of Sjögren's Living with Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place to Begin Family & ... Treatments Patient Information Living with Sjögren's Survey Sjögren’s Clinical Trial Locations Clinical Trials – What’s Involved Video: A Place ...

  13. Competition between magnetic catalysis effect and chiral rotation effect (United States)

    Wang, Lingxiao; Cao, Gaoqing


    In this work, we explore the competition between magnetic catalysis effect and chiral rotation effect in a general parallel electromagnetic field within the effective Nambu-Jona-Lasinio model. For a given electric field E at zero temperature, the mass gap shows three different features with respect to an increasing magnetic field B : increasing monotonically, decreasing after increasing, and decreasing monotonically. By making use of strong magnetic field approximation, we illuminate that this is due to the competition between catalysis effect and chiral rotation effect induced both by the magnetic field, and a critical electric field √{e Ec }=86.4 MeV is found beyond which the mass gap will eventually decrease at large B . As only large magnetic field is relevant for the derivation, the critical electric field does not depend on the temperature T or chemical potential μ .

  14. Heterogeneous Catalysis of Polyoxometalate Based Organic–Inorganic Hybrids (United States)

    Ren, Yuanhang; Wang, Meiyin; Chen, Xueying; Yue, Bin; He, Heyong


    Organic–inorganic hybrid polyoxometalate (POM) compounds are a subset of materials with unique structures and physical/chemical properties. The combination of metal-organic coordination complexes with classical POMs not only provides a powerful way to gain multifarious new compounds but also affords a new method to modify and functionalize POMs. In parallel with the many reports on the synthesis and structure of new hybrid POM compounds, the application of these compounds for heterogeneous catalysis has also attracted considerable attention. The hybrid POM compounds show noteworthy catalytic performance in acid, oxidation, and even in asymmetric catalytic reactions. This review summarizes the design and synthesis of organic–inorganic hybrid POM compounds and particularly highlights their recent progress in heterogeneous catalysis. PMID:28788017

  15. Hydrogen tunneling links protein dynamics to enzyme catalysis. (United States)

    Klinman, Judith P; Kohen, Amnon


    The relationship between protein dynamics and function is a subject of considerable contemporary interest. Although protein motions are frequently observed during ligand binding and release steps, the contribution of protein motions to the catalysis of bond making/breaking processes is more difficult to probe and verify. Here, we show how the quantum mechanical hydrogen tunneling associated with enzymatic C-H bond cleavage provides a unique window into the necessity of protein dynamics for achieving optimal catalysis. Experimental findings support a hierarchy of thermodynamically equilibrated motions that control the H-donor and -acceptor distance and active-site electrostatics, creating an ensemble of conformations suitable for H-tunneling. A possible extension of this view to methyl transfer and other catalyzed reactions is also presented. The impact of understanding these dynamics on the conceptual framework for enzyme activity, inhibitor/drug design, and biomimetic catalyst design is likely to be substantial.

  16. Storied Emotional Distances in the Relationships between Beginning Teachers and School Principals (United States)

    Lassila, Erkki T.; Timonen, Virpi; Uitto, Minna; Estola, Eila


    Recent research has acknowledged the importance of the relationships of school principals with beginning teachers. However, little is known about how emotions inform these relationships from the beginning teacher's side. Applying the concept of emotional geographies, this paper explores the kinds of storied emotional distances that appear in the…

  17. Integrating the teaching role into one's identity : a qualitative study of beginning undergraduate medical teachers

    NARCIS (Netherlands)

    Van, Lankveld T.; Schoonenboom, J.; Kusurkar, R.A.; Volman, M.; Beishuizen, J.; Croiset, G.


    Beginning medical teachers often see themselves as doctors or researchers rather than as teachers. Using both figured worlds theory and dialogical self theory, this study explores how beginning teachers in the field of undergraduate medical education integrate the teacher role into their identity. A

  18. Catalysis in the alkylation reaction of 1-naphthol with epichlorohydrin

    Directory of Open Access Journals (Sweden)



    Full Text Available Two new and improved procedures were developed for the synthesis of 1-(1-naphthyloxy-2,3-epoxypropane as an important intermediate in the production of the beta-blocker and antioxidant, 1-[(1-methylethylamino]-3-(1-naphthyloxy-2-propanol (propranolol. Both base homogeneous and heterogeneous PTC catalysis were employed. High yields and remarkable selectivity were achieved. The improved purity is particularly important, in view of the quality requirements for propranolol hydrochloride as an active pharmaceutical ingredient.

  19. Bionic catalysis of porphyrin for electrochemical detection of nucleic acids

    International Nuclear Information System (INIS)

    Li Jie; Lei Jianping; Wang Quanbo; Wang Peng; Ju Huangxian


    Highlights: ► This is the first application of bionic catalysis of porphyrin as detection probe in bioanalysis. ► Porphyrin–DNA–gold nanoparticle probe is synthesized. ► Binding model between FeTMPyP and DNA is verified. ► The detection probe shows excellent electrocatalytic behaviors toward the reduction of O 2 . ► The biosensor exhibited good performance with wide linear range and high specificity. - Abstract: A novel electrochemical strategy was designed for the detection of DNA based on the bionic catalysis of porphyrin. The detection probe was prepared via the assembly of thiolated double strand DNA (dsDNA) with gold nanoparticles (AuNPs), and then interacted with cationic iron (III) meso-tetrakis (N-methylphyridinum-4-yl) porphyrin (FeTMPyP) via groove binding along the dsDNA surface. The resulting nanocomplex was characterized with transmission electron microscopy, UV–vis absorption and circular dichroism spectroscopy. The FeTMPyP–DNA–AuNPs probe on gold electrode demonstrated the excellent electrocatalytic behaviors toward the reduction of O 2 due to the largely loading of FeTMPyP and good conductivity. Based on bionic catalysis of porphyrin for the reduction of O 2 , the resulting biosensor exhibited a good performance for the detection of DNA with a wide linear range from 1 × 10 −12 to 1 × 10 −8 mol L −1 and detection limit of 2.5 × 10 −13 mol L −1 at the signal/noise of 3. More importantly, the biosensor presented excellent ability to discriminate the perfectly complementary target and the mismatched stand. This strategy could be conveniently extended for detection of other biomolecules. To the best of our knowledge, this is the first application of bionic catalysis of porphyrin as detection probe and opens new opportunities for sensitive detection of biorecognition events.

  20. Asymmetric photoredox transition-metal catalysis activated by visible light (United States)

    Huo, Haohua; Shen, Xiaodong; Wang, Chuanyong; Zhang, Lilu; Röse, Philipp; Chen, Liang-An; Harms, Klaus; Marsch, Michael; Hilt, Gerhard; Meggers, Eric


    Asymmetric catalysis is seen as one of the most economical strategies to satisfy the growing demand for enantiomerically pure small molecules in the fine chemical and pharmaceutical industries. And visible light has been recognized as an environmentally friendly and sustainable form of energy for triggering chemical transformations and catalytic chemical processes. For these reasons, visible-light-driven catalytic asymmetric chemistry is a subject of enormous current interest. Photoredox catalysis provides the opportunity to generate highly reactive radical ion intermediates with often unusual or unconventional reactivities under surprisingly mild reaction conditions. In such systems, photoactivated sensitizers initiate a single electron transfer from (or to) a closed-shell organic molecule to produce radical cations or radical anions whose reactivities are then exploited for interesting or unusual chemical transformations. However, the high reactivity of photoexcited substrates, intermediate radical ions or radicals, and the low activation barriers for follow-up reactions provide significant hurdles for the development of efficient catalytic photochemical processes that work under stereochemical control and provide chiral molecules in an asymmetric fashion. Here we report a highly efficient asymmetric catalyst that uses visible light for the necessary molecular activation, thereby combining asymmetric catalysis and photocatalysis. We show that a chiral iridium complex can serve as a sensitizer for photoredox catalysis and at the same time provide very effective asymmetric induction for the enantioselective alkylation of 2-acyl imidazoles. This new asymmetric photoredox catalyst, in which the metal centre simultaneously serves as the exclusive source of chirality, the catalytically active Lewis acid centre, and the photoredox centre, offers new opportunities for the `green' synthesis of non-racemic chiral molecules.

  1. Nanoporous gold membranes: From morphological control to fuel cell catalysis (United States)

    Ding, Yi

    Porous noble metals are particularly attractive for scientific research and industrial applications such as catalysis, sensing, and filtration. In this thesis, I will discuss the fabrication, characterization, and application of a new class of porous metals, called nanoporous metals (NPM). NPM is made during selective dissolution (also called dealloying) of reactive components (e.g., silver) from multi-component alloys (e.g., Ag/Au alloy). Commercially available white gold leaf (Ag65Au35) can, for example, be etched into nanoporous gold (NPG) membrane by simply floating the leaf on concentrated nitric acid for periods of a few minutes. NPG leaf adopts a single crystal porous structure within individual grains. The microstructure of NPG, such as the pore size, is tunable between a few nanometers to sub-micron length scale by either thermal annealing or post-treatment in nitric acid for extended period of time. A new gas-liquid-solid interface electroless plating technique is developed to uniformly cover the NPG surface with other metals, such as silver and platinum. This technique allows new opportunities of making functionalized nanostructures. We show that a combination of silver plating and dealloying can be used to make multimodal porous metals, which are expected to have application in sensing field. Electroless platinum plating onto NPG shows very usual growth mode. TEM observation indicates that the platinum layer on NPG surface takes a novel form of layer-islanding growth (Stranski-Krastanov growth). Annealing the Pt/NPG composite smoothens the Pt islands and forms a 1 nm coherent Pt layer on the NPG backbone, possibly with dislocation formation at the Pt/Au interface. Furthermore, it was found that we could dissolve the gold away in aqueous gold etchant, leaving behind the 1 nm-thick Pt shell, a structure we call nanotubular mesoporous platinum (NMP). Pt plated NPG has a series of unique structural properties, such as high active surface area, thermally

  2. Crown ethers and phase transfer catalysis in polymer science

    CERN Document Server

    Carraher, Charles


    Phase transfer catalysis or interfacial catalysis is a syn­ thetic technique involving transport of an organic or inorganic salt from a solid or aqueous phase into an organic liquid where reaction with an organic-soluble substrate takes place. Over the past 15 years there has been an enormous amount of effort invested in the development of this technique in organic synthe­ sis. Several books and numerous review articles have appeared summarizing applications in which low molecular weight catalysts are employed. These generally include either crown ethers or onium salts of various kinds. While the term phase transfer catalysis is relatively new, the concept of using a phasetrans­ fer agent (PTA) is much older~ Both Schnell and Morgan employed such catalysts in synthesis of polymeric species in the early 1950's. Present developments are really extensions of these early applications. It has only been within the last several years that the use of phase transfer processes have been employed in polymer synthesis...

  3. Switching on elusive organometallic mechanisms with photoredox catalysis. (United States)

    Terrett, Jack A; Cuthbertson, James D; Shurtleff, Valerie W; MacMillan, David W C


    Transition-metal-catalysed cross-coupling reactions have become one of the most used carbon-carbon and carbon-heteroatom bond-forming reactions in chemical synthesis. Recently, nickel catalysis has been shown to participate in a wide variety of C-C bond-forming reactions, most notably Negishi, Suzuki-Miyaura, Stille, Kumada and Hiyama couplings. Despite the tremendous advances in C-C fragment couplings, the ability to forge C-O bonds in a general fashion via nickel catalysis has been largely unsuccessful. The challenge for nickel-mediated alcohol couplings has been the mechanistic requirement for the critical C-O bond-forming step (formally known as the reductive elimination step) to occur via a Ni(III) alkoxide intermediate. Here we demonstrate that visible-light-excited photoredox catalysts can modulate the preferred oxidation states of nickel alkoxides in an operative catalytic cycle, thereby providing transient access to Ni(III) species that readily participate in reductive elimination. Using this synergistic merger of photoredox and nickel catalysis, we have developed a highly efficient and general carbon-oxygen coupling reaction using abundant alcohols and aryl bromides. More notably, we have developed a general strategy to 'switch on' important yet elusive organometallic mechanisms via oxidation state modulations using only weak light and single-electron-transfer catalysts.

  4. Peptide-capped nanoparticles for catalysis and assembly (United States)

    Briggs, Beverly D.

    Nature possesses methods for the formation and manipulation of inorganic materials with controlled size, shape, and compositions. Biomolecules, such as peptides, are known to be responsible for the generation of such inorganic materials on the nanoscale, where the enhanced properties can be exploited for various applications. Pd nanoparticles, capped with the Pd-specific Pd4 peptide (TSNAVHPTLRHL), were found to be active catalysts for Stille coupling, where the debated mechanism of oxidative addition was explored. Furthermore, the same Pd4-capped nanoparticles were found to be active in Suzuki coupling, another C-C coupling reaction that undergoes catalysis following a similar mechanism. Other considerations with peptide-capped metal catalysis involved the role of the reductant and the subsequent effects on morphology and reactivity, as seen by use of Au nanoparticles capped with a library of peptides. The role of the reductant was studied using varied reductants and was found to directly affect the catalytic activity. Additionally, such Au and Ag materials-binding peptides were expanded to generate multi-domain biomolecules capable of metal-specific binding and nanoparticle assembly. Such in-depth studies of peptide-capped nanomaterials and their uses in catalysis and assembly is important for optimized functionality and application.

  5. Beginning programming with Python for dummies

    CERN Document Server

    Mueller, John Paul


    Learn Python-the fun and easy way-and get in the programming game today! Python is one of the fastest growing programming languages, and no wonder. It requires three to five times less time than developing in Java, is a great building block for learning both procedural and object-oriented programming concepts, and is an ideal language for data analysis. Beginning Programming with Python For Dummies is the perfect guide to this dynamic and powerful programming language-even if you''ve never coded before! Author John Paul Mueller draws on his vast programming knowledge and experience to guide yo

  6. Behaviorism and the beginnings of close reading. (United States)

    Gang, Joshua


    Many of close reading's most enduring assumptions and techniques have their origins in psychological behaviorism. Beginning with I. A. Richards's critical work from the 1920s, this article demonstrates the central place of behaviorist ideas in New Critical theories of poetry. Despite explicitly disparaging Richards's behavioristic poetics, Brooks's Well Wrought Urn and Wimsatt and Beardsley's "intentional fallacy" perpetuated behaviorism's influence on literary criticism. This article traces how the New Critics translated behavioristic psychology into poetic formalism and discusses the implications of this for contemporary critical practice.

  7. Beginning C# Object-Oriented Programming

    CERN Document Server

    Clark, Dan


    Beginning C# Object-Oriented Programming brings you into the modern world of development as you master the fundamentals of programming with C# and learn to develop efficient, reusable, elegant code through the object-oriented programming (OOP) methodology. Take your skills out of the 20th century and into this one with Dan Clark's accessible, quick-paced guide to C# and object-oriented programming, completely updated for .NET 4.0 and C# 4.0. As you develop techniques and best practices for coding in C#, one of the world's most popular contemporary languages, you'll experience modeling a "real

  8. Beginning database design from novice to professional

    CERN Document Server

    Churcher, Clare


    Beginning Database Design, Second Edition provides short, easy-to-read explanations of how to get database design right the first time. This book offers numerous examples to help you avoid the many pitfalls that entrap new and not-so-new database designers. Through the help of use cases and class diagrams modeled in the UML, you'll learn to discover and represent the details and scope of any design problem you choose to attack. Database design is not an exact science. Many are surprised to find that problems with their databases are caused by poor design rather than by difficulties in using th

  9. Is cloud computing finally beginning to mature?


    Dimitrios Zissis; Dimitrios Lekkas


    The buzz term that came into popularity in the beginning of 2006 to describe an innovative IT deployment architecture, originated from the cloud metaphor that was used to represent the Internet in various network diagrams as early as the 1990s. In a short period of time after the term appeared, cloud solutions were being rapidly marketed by many IT companies and various new buzz words came into vogue such as "cloud in a can", "cloud bursting", and we suddenly had “blue clouds”, “green clouds”...

  10. Beginning programming with Java for dummies

    CERN Document Server

    Burd, Barry


    A practical introduction to programming with Java Beginning Programming with Java For Dummies, 4th Edition is a comprehensive guide to learning one of the most popular programming languages worldwide. This book covers basic development concepts and techniques through a Java lens. You'll learn what goes into a program, how to put the pieces together, how to deal with challenges, and how to make it work. The new Fourth Edition has been updated to align with Java 8, and includes new options for the latest tools and techniques. Java is the predominant language used to program Android and cloud app

  11. Beginning Python from novice to professional

    CERN Document Server

    Hetland, Magnus Lie


    ""Beginning Python: From Novice to Professional"" is the most comprehensive book on the Python ever written. Based on ""Practical Python,"" this newly revised book is both an introduction and practical reference for a swath of Python-related programming topics, including addressing language internals, database integration, network programming, and web services. Advanced topics, such as extending Python and packaging/distributing Python applications, are also covered. Ten different projects illustrate the concepts introduced in the book. You will learn how to create a P2P file-sharing applicati

  12. Catalysis in electrochemistry from fundamental aspects to strategies for fuel cell development

    CERN Document Server

    Santos, Elizabeth


    Catalysis in Electrochemistry: From Fundamental Aspects to Strategies for Fuel Cell Development is a modern, comprehensive reference work on catalysis in electrochemistry, including principles, methods, strategies, and applications. It points out differences between catalysis at gas/surfaces and electrochemical interfaces, along with the future possibilities and impact of electrochemical science on energy problems. This book contributes both to fundamental science; experience in the design, preparation, and characterization of electrocatalytic materials; and the industrial application o

  13. Catalysis by Atomic-Sized Centers: Methane Activation for Partial Oxidation and Combustion (United States)



  14. Molecular Catalysis at Polarized Interfaces Created by Ferroelectric BaTiO3 (Postprint) (United States)


    AFRL-RX-WP-JA-2016-0197 MOLECULAR CATALYSIS AT POLARIZED INTERFACES CREATED BY FERROELECTRIC BaTiO3 (POSTPRINT) Eugene S. Beh, Xiaofeng Feng, and...TITLE AND SUBTITLE MOLECULAR CATALYSIS AT POLARIZED INTERFACES CREATED BY FERROELECTRIC BaTiO3 (POSTPRINT) 5a. CONTRACT NUMBER FA8650-09-D-5434...way to inves- tigate and exploit the effects of interfacial polarization on catalysis . Acknowledgements We thank the Air Force Office of Scientic

  15. Combining Zn Ion Catalysis with Homogeneous Gold Catalysis: An Efficient Annulation Approach toN-Protected Indoles. (United States)

    Wang, Yanzhao; Liu, Lianzhu; Zhang, Liming


    The Fischer indole synthesis is perhaps the most powerful method for indole preparation, but it often suffers from low regioselectivities with unsymmetric aliphatic ketone substrates and strong acidic conditions and is not suitable for α,β-unsaturated ketones. In this article, we disclose an efficient synthesis of N -protected indoles from N -arylhydroxamic acids/ N -aryl- N- hydroxycarbamates and a variety of alkynes via a cooperative gold and zinc catalysis. The zinc catalysis is similar to the related zinc ion catalysis in metalloenzymes such as human carbonic anhydrase II and substantially enhances the O -nucleophilicity of N -acylated hydroxamines by forming the corresponding Zn chelates. The Zn chelates can attack gold-activated alkynes to form O- alkenyl- N -arylhydroxamates, which can undergo facile 3,3-sigmatropic rearrangements and subsequent cyclodehydrations to yield N -protected indole products. This new chemistry offers several important improvements over the Fischer indole synthesis: a) the reaction conditions are mildly acidic and can tolerate sensitive groups such as Boc; b) broader substrate scopes including substrates with pendant carbonyl groups (reactive in the Fischer chemistry) and alkyl chlorides (e.g., 3f ); c) better regioselectivities for the formation of 2-substituted indoles under much milder conditions; d) 2-alkenylindoles can be prepared readily in good to excellent yields, but the Fischer chemistry could not; e) with internal alkynes both steric and electronic controls are available for achieving good regioselectivities, while the Fischer chemistry is in general problematic.

  16. From student to beginning teacher: Learning strengths and teaching challenges

    Directory of Open Access Journals (Sweden)

    Monica McGlynn-Stewart


    Full Text Available This research examined how the professional practice of Canadian beginning elementary teachers was influenced by their own early learning experiences in school. Six teachers were observed and interviewed in their classrooms five times over the first three years of their teaching career. Case studies were developed for each teacher and themes were explored across cases. The findings from this study suggest that pre-service and in-service teacher education programs need to provide teachers with opportunities to critically examine how their relative strengths and weaknesses as pupils may affect their performance and identity as teachers.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Alexis T. [Univ. of California, Berkeley, CA (United States); Alger, Monty M. [Pennsylvania State Univ., University Park, PA (United States); Flytzani-Stephanopoulos, Maria [Tufts Univ., Medford, MA (United States); Gunnoe, T. Brent [Univ. of Virginia, Charlottesville, VA (United States); Lercher, Johannes A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stevens, James [Dow Chemical Company, Torrance, CA (United States); Alper, Joe; Tran, Camly [National Academies of Sciences, Engineering, and Medicine, Washington, DC (United States)


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

  18. Understanding the Relationship Between Kinetics and Thermodynamics in CO 2 Hydrogenation Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Jeletic, Matthew S. [Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Hulley, Elliott B. [Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Helm, Monte L. [Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Mock, Michael T. [Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Appel, Aaron M. [Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Wiedner, Eric S. [Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Linehan, John C. [Catalysis Science Group, Pacific Northwest National Laboratory, Richland, Washington 99352, United States


    Linear free-energy relationships have been identified that link the kinetic activity for catalytic hydrogenation of CO2 to formate with the thermodynamic driving force for the rate-limiting steps of catalysis. Cobalt and rhodium bis(diphosphine) complexes with different hydricities (G°H-), acidities (pKa), and free energies for H2 addition (G°H2) were examined. Catalytic CO2 hydrogenation was studied under 1.8 and 20 atm of pressure (1:1 CO2:H2) at room temperature in tetrahydrofuran with a spread of turnover frequencies (TOF) ranging from 0 to 74,000 h-1. The catalysis was followed by 1H and 31P NMR in real time under all conditions to yield information about the rate determining step. Catalysts exhibiting the highest activities were found to have hydride transfer and hydrogen addition steps that were each downhill by approximately 6 to 7 kcal/mol, and the deprotonation step was thermoneutral. The research by M.S.J., A.M.A., E.S.W., and J.C.L. was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences. The research by E.B.H., M.L.H., and M.T.M. (X-ray crystallography, synthesis) was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. The authors thank Dr. Samantha A. Burgess for assistance in collecting cyclic voltammetry data. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  19. Before the beginning our universe and others

    CERN Document Server

    Rees, Martin


    "Although we cannot observe them (and they may be forever inaccessible), other universes are a natural expectation from current cosmology. Moreover, many features of our universe that otherwise seem baffling fall into place once we recognize this." Sir Martin Rees, the British Astronomer Royal, gives a vivid, occasionally acid tour of current astrophysics and cosmology, with insights into scientific politics, such as the enormous increase in the cost of the space telescope because of its association with the Space Shuttle. He also offers keen observations on personalities such as Subrahmayan Chandrasekhar and Isaac Newton, Yakov Zeldovich and Albert Einstein. Joseph Silk calls Before the Beginning "an unusual blend of wit, asperity and cosmology ... a combination of clarity and conciseness."

  20. Beginning iPhone Games Development

    CERN Document Server

    Cabera, P; Marsh, Ian; Smith, Ben; Wing, Eric


    iPhone games are hot! Just look at the numbers. Games make up over 25 percent of total apps and over 70 percent of the most popular apps. Surprised? Of course not! Most of us have filled our iPhone or iPod touch with games, and many of us hope to develop the next best-selling, most talked-about game. You've probably already read and mastered Beginning iPhone 3 Development; Exploring the iPhone SDK, the best-selling, the second edition of Apress's highly acclaimed introduction to the iPhone and iPod touch by developers Dave Mark and Jeff LaMarche. This book is the game-specific equivalent, prov

  1. How to Begin a Quality Improvement Project. (United States)

    Silver, Samuel A; Harel, Ziv; McQuillan, Rory; Weizman, Adam V; Thomas, Alison; Chertow, Glenn M; Nesrallah, Gihad; Bell, Chaim M; Chan, Christopher T


    Quality improvement involves a combined effort among health care staff and stakeholders to diagnose and treat problems in the health care system. However, health care professionals often lack training in quality improvement methods, which makes it challenging to participate in improvement efforts. This article familiarizes health care professionals with how to begin a quality improvement project. The initial steps involve forming an improvement team that possesses expertise in the quality of care problem, leadership, and change management. Stakeholder mapping and analysis are useful tools at this stage, and these are reviewed to help identify individuals who might have a vested interest in the project. Physician engagement is a particularly important component of project success, and the knowledge that patients/caregivers can offer as members of a quality improvement team should not be overlooked. After a team is formed, an improvement framework helps to organize the scientific process of system change. Common quality improvement frameworks include Six Sigma, Lean, and the Model for Improvement. These models are contrasted, with a focus on the Model for Improvement, because it is widely used and applicable to a variety of quality of care problems without advanced training. It involves three steps: setting aims to focus improvement, choosing a balanced set of measures to determine if improvement occurs, and testing new ideas to change the current process. These new ideas are evaluated using Plan-Do-Study-Act cycles, where knowledge is gained by testing changes and reflecting on their effect. To show the real world utility of the quality improvement methods discussed, they are applied to a hypothetical quality improvement initiative that aims to promote home dialysis (home hemodialysis and peritoneal dialysis). This provides an example that kidney health care professionals can use to begin their own quality improvement projects. Copyright © 2016 by the American

  2. Kokes Awards for the 25th North American Catalysis Society Meeting

    Energy Technology Data Exchange (ETDEWEB)

    Pylypenko, Svitlana [Colorado School of Mines, Golden, CO, US, Chemistry Department


    The biennial North American Catalysis Society (NACS) meeting is the premiere conferences in the area of catalysis, surface science, and reaction engineering. The 25th installment of this meeting will be held the week of June 4-9, 2017 in Denver, CO at the Hyatt Regency Hotel. Meeting objectives include bringing together leading researchers for intensive scientific exchange, providing students with an opportunity to present their work and interact with leaders in the field, and participate in service to scientific/technical community. Financial support to offset a portion of the associated costs – and specifically, registration fees, airline tickets, and hotel accommodations – encourages greater participation by graduate and undergraduate students, and often provides them the only opportunity to attend and meaningfully contribute to the conference. The funds sought in this proposal will be in support of the Richard J. Kokes Travel Award program. The eligibility criteria for undergraduates and graduate students applying for a merit-based Awards are that they must study at a university within the United States and present either a poster or presentation at the meeting. In the previous meeting in Pittsburgh, NACS received 200 applications and funded 110 students. Similarly, during the meeting in Louisville, NACS received 225 applications and funded nearly half of them. The NACS has an on-going tradition of encouraging graduate students (and more recently, undergraduates as well) to participate in and serve at the national meetings Providing financial support is one of the most effective means of accomplishing this goal. Their attendance significantly broadens their scientific training beyond what can be accomplished in the classroom, and offers them an opportunity to improve their communication and presentation skills. As an attendee to the 25th NAM, students will participate by listening to presentations from leading researchers from the U.S. and abroad, and they

  3. The effect of hot electrons and surface plasmons on heterogeneous catalysis

    International Nuclear Information System (INIS)

    Kim, Sun Mi; Lee, Si Woo; Moon, Song Yi; Park, Jeong Young


    Hot electrons and surface-plasmon-driven chemistry are amongst the most actively studied research subjects because they are deeply associated with energy dissipation and the conversion processes at the surface and interfaces, which are still open questions and key issues in the surface science community. In this topical review, we give an overview of the concept of hot electrons or surface-plasmon-mediated hot electrons generated under various structural schemes (i.e. metals, metal–semiconductor, and metal–insulator–metal) and their role affecting catalytic activity in chemical reactions. We highlight recent studies on the relation between hot electrons and catalytic activity on metallic surfaces. We discuss possible mechanisms for how hot electrons participate in chemical reactions. We also introduce controlled chemistry to describe specific pathways for selectivity control in catalysis on metal nanoparticles. (topical review)

  4. Bottom-Up Meets Top-Down: Patchy Hybrid Nonwovens as an Efficient Catalysis Platform. (United States)

    Schöbel, Judith; Burgard, Matthias; Hils, Christian; Dersch, Roland; Dulle, Martin; Volk, Kirsten; Karg, Matthias; Greiner, Andreas; Schmalz, Holger


    Heterogeneous catalysis with supported nanoparticles (NPs) is a highly active field of research. However, the efficient stabilization of NPs without deteriorating their catalytic activity is challenging. By combining top-down (coaxial electrospinning) and bottom-up (crystallization-driven self-assembly) approaches, we prepared patchy nonwovens with functional, nanometer-sized patches on the surface. These patches can selectively bind and efficiently stabilize gold nanoparticles (AuNPs). The use of these AuNP-loaded patchy nonwovens in the alcoholysis of dimethylphenylsilane led to full conversion under comparably mild conditions and in short reaction times. The absence of gold leaching or a slowing down of the reaction even after ten subsequent cycles manifests the excellent reusability of this catalyst system. The flexibility of the presented approach allows for easy transfer to other nonwoven supports and catalytically active NPs, which promises broad applicability. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Catalysis as a foundational pillar of green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Anastas, Paul T. [White House Office of Science and Technology Policy, Department of Chemistry, University of Nottingham Nottingham, (United Kingdom); Kirchhoff, Mary M. [U.S. Environmental Protection Agency and Trinity College, Washington, DC (United States); Williamson, Tracy C. [U.S. Environmental Protection Agency, Washington, DC (United States)


    Catalysis is one of the fundamental pillars of green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. The design and application of new catalysts and catalytic systems are simultaneously achieving the dual goals of environmental protection and economic benefit. Green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, is an overarching approach that is applicable to all aspects of chemistry. From feedstocks to solvents, to synthesis and processing, green chemistry actively seeks ways to produce materials in a way that is more benign to human health and the environment. The current emphasis on green chemistry reflects a shift away from the historic 'command-and-control' approach to environmental problems that mandated waste treatment and control and clean up through regulation, and toward preventing pollution at its source. Rather than accepting waste generation and disposal as unavoidable, green chemistry seeks new technologies that are cleaner and economically competitive. Utilizing green chemistry for pollution prevention demonstrates the power and beauty of chemistry: through careful design, society can enjoy the products on which we depend while benefiting the environment. The economic benefits of green chemistry are central drivers in its advancement. Industry is adopting green chemistry methodologies because they improve the corporate bottom line. A wide array of operating costs are decreased through the use of green chemistry. When less waste is generated, environmental compliance costs go down. Treatment and disposal become unnecessary when waste is eliminated. Decreased solvent usage and fewer processing steps lessen the material and energy costs of manufacturing and increase material efficiency. The environmental, human health, and the economic advantages realized through green chemistry

  6. VLT Data Flow System Begins Operation (United States)


    conceived as a complex digital facility to explore the Universe. In order for astronomers to be able to use this marvellous research tool in the most efficient manner possible, the VLT computer software and hardware systems must guarantee a smooth flow of scientific information through the entire system. This process starts when the astronomers submit well-considered proposals for observing time and it ends with large volumes of valuable astronomical data being distributed to the international astronomical community. For this, ESO has produced an integrated collection of software and hardware, known as the VLT Data Flow System (DFS) , that manages and facilitates the flow of scientific information within the VLT Observatory. Early information about this new concept was published as ESO Press Release 12/96 and extensive tests were first carried out at ESOs 3.5-m New Technology Telescope (NTT) at La Silla, cf. ESO Press Release 03/97 [1]. The VLT DFS is a complete (end-to-end) system that guarantees the highest data quality by optimization of the observing process and repeated checks that identify and eliminate any problems. It also introduces automatic calibration of the data, i.e. the removal of external effects introduced by the atmospheric conditions at the time of the observations, as well as the momentary state of the telescope and the instruments. From Proposals to Observations In order to obtain observing time with ESO telescopes, also with the VLT, astronomers must submit a detailed observing proposal to the ESO Observing Programmes Committee (OPC) . It meets twice a year and ranks the proposals according to scientific merit. More than 1000 proposals are submitted each year, mostly by astronomers from the ESO members states and Chile; the competition is fierce and only a fraction of the total demand for observing time can be fulfilled. During the submission of observing proposals, DFS software tools available over the World Wide Web enable the astronomers to simulate

  7. Radio catalysis application in degradation of complex organic samples

    International Nuclear Information System (INIS)

    Moreno L, A.


    The generation of wastewater is a consequence of human activities, industries to be the generators of a large part of these discharges. These contaminated waters can be processed for their remediation; however the recalcitrant organic compounds are hardly removed through conventional treatments applied, so that new technologies have been developed for disposal such as the advanced oxidation technologies or processes. With the aim of the study is to apply ionizing radiation as a method of remediation in wastewater, in this work were carried out experiments of radiolysis and radio catalysis, which are techniques considered advanced oxidation technologies, that consist in irradiate with 60 Co gamma radiation solutions of 4- chloro phenol and methylene blue, applied at different concentrations and using as process control measurements of the compound not degraded by UV-vis spectrophotometry at 507 and 664 nm for 4-chloro phenol and methylene blue respectively. At doses greater than 2.5 kGy were near-zero degradation. Degradation experiments were also conducted by photo catalysis by irradiation with a UV lamp of 354 nm wavelength. For 4-chloro phenol results showed that degradation is efficient (39%). With those previous results, these techniques were applied to degrade complex mixtures of organic compounds from samples of wastewater from a sewage treatment plant, where was considered as process control measurement of the dissolved organic carbon obtained by a spectrophotometric analysis at 254 nm, and a maximum of 26% degradation was obtained by applying 80 kGy. On the other hand, a series of experiments fractionating the irradiations at intervals of 20 kGy to obtain a cumulative dose of 80 kGy, which was 2.8 times greater with respect to degradation by radio catalysis with continuous irradiation. (Author)

  8. Organocatalysis: Fundamentals and Comparisons to Metal and Enzyme Catalysis

    Directory of Open Access Journals (Sweden)

    Pierre Vogel


    Full Text Available Catalysis fulfills the promise that high-yielding chemical transformations will require little energy and produce no toxic waste. This message is carried by the study of the evolution of molecular catalysis of some of the most important reactions in organic chemistry. After reviewing the conceptual underpinnings of catalysis, we discuss the applications of different catalysts according to the mechanism of the reactions that they catalyze, including acyl group transfers, nucleophilic additions and substitutions, and C–C bond forming reactions that employ umpolung by nucleophilic additions to C=O and C=C double bonds. We highlight the utility of a broad range of organocatalysts other than compounds based on proline, the cinchona alkaloids and binaphthyls, which have been abundantly reviewed elsewhere. The focus is on organocatalysts, although a few examples employing metal complexes and enzymes are also included due to their significance. Classical Brønsted acids have evolved into electrophilic hands, the fingers of which are hydrogen donors (like enzymes or other electrophilic moieties. Classical Lewis base catalysts have evolved into tridimensional, chiral nucleophiles that are N- (e.g., tertiary amines, P- (e.g., tertiary phosphines and C-nucleophiles (e.g., N-heterocyclic carbenes. Many efficient organocatalysts bear electrophilic and nucleophilic moieties that interact simultaneously or not with both the electrophilic and nucleophilic reactants. A detailed understanding of the reaction mechanisms permits the design of better catalysts. Their construction represents a molecular science in itself, suggesting that sooner or later chemists will not only imitate Nature but be able to catalyze a much wider range of reactions with high chemo-, regio-, stereo- and enantioselectivity. Man-made organocatalysts are much smaller, cheaper and more stable than enzymes.

  9. Direct synthesis of macrodiolides via hafnium(IV) catalysis. (United States)

    de Léséleuc, Mylène; Collins, Shawn K


    Efficient direct synthesis of macrodiolides via catalysis using Hf(OTf)4 is possible in high yields, forming water as the sole by-product. The first protocol for the direct synthesis of macrodiolides from equimolar mixtures of diols and dicarboxylic acids was developed (58-96%). In addition, modification of the reaction concentration allows for the synthesis of head-to-tail macrodiolides from the corresponding seco acids. The catalytic preparation of the macrodiolides using a commercially available catalyst without the need for slow addition or azeotropic condition provides an operationally simple alternative to protocols which employ toxic tin catalysts or stoichiometric activation strategies.

  10. Catalysis of Protein Disulfide Bond Isomerization in a Homogeneous Substrate† (United States)

    Kersteen, Elizabeth A.; Barrows, Seth R.; Raines, Ronald T.


    Protein disulfide isomerase (PDI) catalyzes the rearrangement of nonnative disulfide bonds in the endoplasmic reticulum of eukaryotic cells, a process that often limits the rate at which polypeptide chains fold into a native protein conformation. The mechanism of the reaction catalyzed by PDI is unclear. In assays involving protein substrates, the reaction appears to involve the complete reduction of some or all of its nonnative disulfide bonds followed by oxidation of the resulting dithiols. The substrates in these assays are, however, heterogeneous, which complicates mechanistic analyses. Here, we report the first analysis of disulfide bond isomerization in a homogeneous substrate. Our substrate is based on tachyplesin I, a 17-mer peptide that folds into a _-hairpin stabilized by two disulfide bonds. We describe the chemical synthesis of a variant of tachyplesin I in which its two disulfide bonds are in a nonnative state and side chains near its N-and C-terminus contain a fluorescence donor (tryptophan) and acceptor (N_-dansyllysine). Fluorescence resonance energy transfer from 280 to 465 nm increases by 28-fold upon isomerization of the disulfide bonds into their native state (which has a lower E°_ = -0.313 V than does PDI). We use this continuous assay to analyze catalysis by wild-type human PDI and a variant in which the C-terminal cysteine residue within each Cys—Gly—His—Cys active site is replaced with alanine. We find that wild-type PDI catalyzes the isomerization of the substrate with kcat/KM = 1.7 _ 105 M–1M s–1, which is the largest value yet reported for catalysis of disulfide bond isomerization. The variant, which is a poor catalyst of disulfide bond reduction and dithiol oxidation, retains virtually all of the activity of wild-type PDI in catalysis of disulfide bond isomerization. Thus, the C-terminal cysteine residues play an insignificant role in the isomerization of the disulfide bonds in nonnative tachyplesin I. We conclude that

  11. Catalysis of protein disulfide bond isomerization in a homogeneous substrate. (United States)

    Kersteen, Elizabeth A; Barrows, Seth R; Raines, Ronald T


    Protein disulfide isomerase (PDI) catalyzes the rearrangement of nonnative disulfide bonds in the endoplasmic reticulum of eukaryotic cells, a process that often limits the rate at which polypeptide chains fold into a native protein conformation. The mechanism of the reaction catalyzed by PDI is unclear. In assays involving protein substrates, the reaction appears to involve the complete reduction of some or all of its nonnative disulfide bonds followed by oxidation of the resulting dithiols. The substrates in these assays are, however, heterogeneous, which complicates mechanistic analyses. Here, we report the first analysis of disulfide bond isomerization in a homogeneous substrate. Our substrate is based on tachyplesin I, a 17-mer peptide that folds into a beta hairpin stabilized by two disulfide bonds. We describe the chemical synthesis of a variant of tachyplesin I in which its two disulfide bonds are in a nonnative state and side chains near its N and C terminus contain a fluorescence donor (tryptophan) and acceptor (N(epsilon)-dansyllysine). Fluorescence resonance energy transfer from 280 to 465 nm increases by 28-fold upon isomerization of the disulfide bonds into their native state (which has a lower E(o') = -0.313 V than does PDI). We use this continuous assay to analyze catalysis by wild-type human PDI and a variant in which the C-terminal cysteine residue within each Cys-Gly-His-Cys active site is replaced with alanine. We find that wild-type PDI catalyzes the isomerization of the substrate with kcat/K(M) = 1.7 x 10(5) M(-1) s(-1), which is the largest value yet reported for catalysis of disulfide bond isomerization. The variant, which is a poor catalyst of disulfide bond reduction and dithiol oxidation, retains virtually all of the activity of wild-type PDI in catalysis of disulfide bond isomerization. Thus, the C-terminal cysteine residues play an insignificant role in the isomerization of the disulfide bonds in nonnative tachyplesin I. We conclude

  12. Oxy-Allyl Cation Catalysis: An Enantioselective Electrophilic Activation Mode (United States)

    Liu, Chun; Oblak, E. Zachary; Vander Wal, Mark N.; Dilger, Andrew K.; Almstead, Danielle K.; MacMillan, David W. C.


    A generic activation mode for asymmetric LUMO-lowering catalysis has been developed using the long-established principles of oxy-allyl cation chemistry. Here, the enantioselective conversion of racemic α-tosyloxy ketones to optically enriched α-indolic carbonyls has been accomplished using a new amino alcohol catalyst in the presence of electron-rich indole nucleophiles. Kinetic studies reveal that the rate-determining step in this SN1 pathway is the catalyst-mediated α-tosyloxy ketone deprotonation step to form an enantiodiscriminant oxy-allyl cation prior to the stereodefining nucleophilic addition event. PMID:26797012

  13. Decarboxylative Fluorination of Aliphatic Carboxylic Acids via Photoredox Catalysis (United States)

    Ventre, Sandrine; Petronijevic, Filip R.; MacMillan, David W. C.


    The direct conversion of aliphatic carboxylic acids to the corresponding alkyl fluorides has been achieved via visible light-promoted photoredox catalysis. This operationally simple, redox-neutral fluorination method is amenable to a wide variety of carboxylic acids. Photon-induced oxidation of carboxylates leads to the formation of carboxyl radicals, which upon rapid CO2-extrusion and F• transfer from a fluorinating reagent yield the desired fluoroalkanes with high efficiency. Experimental evidence indicates that an oxidative quenching pathway is operable in this broadly applicable fluorination protocol. PMID:25881929

  14. Recent advances in the cycloisomerizations of methylenecyclopropanes under gold catalysis. (United States)

    Shi, Min; Fang, Wei


    During the past decades, cycloisomerizations of methylenecyclopropanes under gold catalysis have attracted much attention from organic chemists. The different patterns of cycloisomerizations have been developed from gold(I)-catalyzed ring-opening and ring-expansion of methylenecyclopropanes. This synthetic methodology provides a new approach to novel cyclic- or polycyclic compounds and even polycyclic aromatic hydrocarbons, organic light emitting materials and biologically active substances. The corresponding products have great potential for material science, medicinal chemistry and total synthesis. This Concept article will mainly focus on the recent advances in the cycloisomerizations of methylenecyclopropanes in the past four year. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Pd/C Catalysis under Microwave Dielectric Heating

    Directory of Open Access Journals (Sweden)

    Elena Cini


    Full Text Available Microwave-assisted organic synthesis (MAOS provides a novel and efficient means of achieving heat organic reactions. Nevertheless, the potential arcing phenomena via microwave (MW interaction with solid metal catalysts has limited its use by organic chemists. As arcing phenomena are now better understood, new applications of Pd/C-catalyzed reactions under MW dielectric heating are now possible. In this review, the state of the art, benefits, and challenges of coupling MW heating with heterogeneous Pd/C catalysis are discussed to inform organic chemists about their use with one of the most popular heterogeneous catalysts.

  16. Research

    African Journals Online (AJOL)



    Apr 20, 2016 ... Abstract. Introduction: There is a lack of published evidence examining the quality of patient notes in African healthcare settings. We aim to examine the completeness of the orthopaedic inpatient notes and begin development of a formal audit framework in a large Tanzanian Hospital. Methods: A.

  17. Understanding the Kinetics and Spectroscopy of Photoredox Catalysis and Transition-Metal-Free Alternatives. (United States)

    Pitre, Spencer P; McTiernan, Christopher D; Scaiano, Juan C


    Over the past decade, the field of photoredox catalysis has gained increasing attention in synthetic organic chemistry because of its wide applicability in sustainable free-radical-mediated processes. Numerous examples have shown that under carefully optimized conditions, efficient and highly selective processes can be developed through excitation of a photosensitizer using inexpensive, readily available light sources. However, despite all of these recent advancements, some generalizations and/or misconceptions have become part of the photoredox culture, and often many of these discoveries lack in-depth investigations into the excited-state kinetics and underlying mechanisms. In this Account, we begin with a tutorial for understanding both the redox properties of excited states and how to measure the kinetics of excited-state processes. We discuss the generalization of direct excitation of closed-shell species to generate more potent reductive or oxidative excited states, using the helium atom as a quantitative example. We also outline how to apply redox potentials to calculate whether the proposed electron transfer events are thermodynamically feasible. In the second half of our tutorial, we discuss how to measure the kinetics of excited-state processes using techniques such as steady-state and time-resolved fluorescence and transient spectroscopy and how to apply the data using Stern-Volmer and kinetic analysis. Then we shift gears to discuss our recent contributions to the field of photoredox catalysis. Our lab focuses on developing transition-metal-free alternatives to ruthenium and iridium bipyridyl complexes for these transformations, with the goal of developing systems in which the reaction kinetics is more favorable. We have found that methylene blue, a member of the thiazine dye family, can be employed in photoredox processes such as oxidative hydroxylations of arylboronic acids to phenols. Interestingly, we were able to demonstrate that methylene blue is

  18. Asymmetric fluorination of α-branched cyclohexanones enabled by a combination of chiral anion phase-transfer catalysis and enamine catalysis using protected amino acids. (United States)

    Yang, Xiaoyu; Phipps, Robert J; Toste, F Dean


    We report a study involving the successful merger of two separate chiral catalytic cycles: a chiral anion phase-transfer catalysis cycle to activate Selectfluor and an enamine activation cycle, using a protected amino acid as organocatalyst. We have demonstrated the viability of this approach with the direct asymmetric fluorination of α-substituted cyclohexanones to generate quaternary fluorine-containing stereocenters. With these two chiral catalytic cycles operating together in a matched sense, high enantioselectivites can be achieved, and we envisage that this dual catalysis method has the potential to be more broadly applicable, given the breadth of enamine catalysis. It also represents a rare example of chiral enamine catalysis operating successfully on α-branched ketones, substrates commonly inert to this activation mode.

  19. Asymmetric Aldol Additions: A Guided-Inquiry Laboratory Activity on Catalysis (United States)

    King, Jorge H. Torres; Wang, Hong; Yezierski, Ellen J.


    Despite the importance of asymmetric catalysis in both the pharmaceutical and commodity chemicals industries, asymmetric catalysis is under-represented in undergraduate chemistry laboratory curricula. A novel guided-inquiry experiment based on the asymmetric aldol addition was developed. Students conduct lab work to compare the effectiveness of…

  20. Homogeneous vs heterogeneous polymerization catalysis revealed by single-particle fluorescence microscopy. (United States)

    Esfandiari, N Melody; Blum, Suzanne A


    A high-sensitivity and high-resolution single-particle fluorescence microscopy technique differentiated between homogeneous and heterogeneous metathesis polymerization catalysis by imaging the location of the early stages of polymerization. By imaging single polymers and single crystals of Grubbs II, polymerization catalysis was revealed to be solely homogeneous rather than heterogeneous or both.

  1. [Prediction of common buffer catalysis in hydrolysis of fenchlorazole-ethyl]. (United States)

    Lin, Jing; Chen, Jing-wen; Zhang, Si-yu; Cai, Xi-yun; Qiao, Xian-liang


    The purpose of this study was to elucidate the effects of temperatures, pH levels and buffer catalysis on the hydrolysis of FCE. The hydrolysis of FCE follows first-order kinetics at different pH levels and temperatures. FCE hydrolysis rates are greatly increased at elevated pH levels and temperatures. The maximum contribution of buffer catalysis to the hydrolysis of FCE was assessed based on application of the Bronsted equations for general acid-base catalysis. The results suggest that the buffer solutions play an obvious catalysis role in hydrolysis of FCE and the hydrolysis rates of FCE are quickened by the buffer solutions. Besides, the buffer catalysis capacity of different buffer solutions is diverse, and the buffer catalysis capacity at different pH levels with the same buffer solutions is different, too. The phosphate buffer at pH = 7 shows the maximal buffer catalysis capacity. The hydrolysis rate constants of FCE as a function of temperature and pH, which were remedied by the buffer catalysis factor, were mathematically combined to predict the hydrolytic dissipation of FCE. The equation suggests that the hydrolysis half-lives of FCE ranged from 7 d to 790 d. Hydrolysis metabolites of FCE were identified by liquid chromatography-mass spectrometry. In basic conditions (pH 8-10), fenchlorazole was formed via breakdown of the ester bond of the safener.

  2. Ir/Sn dual-reagent catalysis towards highly selective alkylation of ...

    Indian Academy of Sciences (India)


    Organometallics and Catalysis Laboratory, Department of Chemistry, Indian Institute of Technology,. Kharagpur 721 302 e-mail: ... Organometallic; bimetallic; catalysis; alkylation; benzyl alcohol; iridium, tin. 1. Introduction. Even after 125 years ..... Lewis-acidic metal catalysed dehydration, β-hydrogen elimination, oxidative ...

  3. Lewis-acid catalysis of carbon carbon bond forming reactions in water

    NARCIS (Netherlands)

    Engberts, JBFN; Feringa, BL; Keller, E; Otto, S


    In this article, we review the recent progress that has been made in the field of Lewis-acid catalysis of carbon carbon-bond-forming reactions in aqueous solution. Since water hampers the hard hard interactions between the catalyst and the reactant, it often complicates catalysis. However, once

  4. The beginnings of piezoelectricity a study in mundane physics

    CERN Document Server

    Katzir, Shaul; Gavroglu, Kostas


    Involving electricity, elasticity, thermodynamics and crystallography, several scientific traditions and approaches and leading physicists, the history of piezoelectricity provides an advantageous perspective on late nineteenth century physics and its development. The beginnings of piezoelectricity, the first history of the subject, exhaustively examines how these diverse influences led to the discovery of the phenomenon in 1880, and how they shaped its subsequent research until the consolidation of an empirical and theoretical knowledge of the field circa 1895. It studies a particular subdiscipline representative of many similar "mundane" branches of physics that did not bear revolutionary consequences beyond their field. Although most research is of this kind, such branches have rarely been studied by historians of science. Shaul Katzir's historical account shows that this mundane science was an intriguing intellectual and practical enterprise, which involved, among other things, originality, surprises and ...

  5. Galen and the beginnings of Western physiology. (United States)

    West, John B


    Galen (129-c. 216 AD) was a key figure in the early development of Western physiology. His teachings incorporated much of the ancient Greek traditions including the work of Hippocrates and Aristotle. Galen himself was a well-educated Greco-Roman physician and physiologist who at one time was a physician to the gladiators in Pergamon. Later he moved to Rome, where he was associated with the Roman emperors Marcus Aurelius and Lucius Verus. The Galenical school was responsible for voluminous writings, many of which are still extant. One emphasis was on the humors of the body, which were believed to be important in disease. Another was the cardiopulmonary system, including the belief that part of the blood from the right ventricle could enter the left through the interventricular septum. An extraordinary feature of these teachings is that they dominated thinking for some 1,300 years and became accepted as dogma by both the State and Church. One of the first anatomists to challenge the Galenical teachings was Andreas Vesalius, who produced a magnificent atlas of human anatomy in 1543. At about the same time Michael Servetus described the pulmonary transit of blood, but he was burned at the stake for heresy. Finally, with William Harvey and others in the first part of the 17th century, the beginnings of modern physiology emerged with an emphasis on hypotheses and experimental data. Nevertheless, vestiges of Galen's teaching survived into the 19th century. Copyright © 2014 the American Physiological Society.

  6. Drawing as a beginning: Case report

    Directory of Open Access Journals (Sweden)

    Stojković-Pavlović Jasmina


    Full Text Available Treatment of patients with affective disorders during hospitalisation at the Institute of Mental Health includes pharmacotherapy, individual supportive therapy, group and expressive therapies including art therapy. Art therapy takes a place weekly, it lasts one hour during which patients paint for twenty minutes and then discuss their paintings in the group for the next forty minutes. In this paper the case of a patient who has been treated as recurrent depressive disorder (F33 and mixed personality disorder (F61 is presented. During previous years of treatment the patient had no inability to verbalise his symptoms and feelings, which led to difficult understanding of his actual psychopathology. After applied integrative treatment, pharmaco – and psychotherapy including expressive – art therapy, with the help of the supportive group, the patient for the first time since the beginning of the treatment spoke about his thoughts and feelings of hopelessness, sorrow, alienation and loneliness. All of the applied psychometric scales have shown improvement, for depression – MADRS, for anxiety – VAS and for functionality – SDS. This clinical example shows how the art therapy and interreaction with the group, which was supportive and highly associative, can turn the non-verbal into verbal and non-communication into communication.

  7. Helicobacter pylori: Beginning the Second Decade

    Directory of Open Access Journals (Sweden)

    Ann Matisko


    Full Text Available ‘Beginning the Second Decade’ - a recent international meeting on Helicobacter pylori - was held in conjunction with the VIIth International Workshop on Gastroduodenal Pathology and H pylori and with the meeting of the European Helicobacter pylori Study Group in Houston, Texas from September 30 to October 1, 1994. A menu of 476 abstracts, published in the American Journal of Gastroenterology (1994;89:8, highlighted the explosion of advances in this area. The Houston meeting was followed by the Tenth World Congresses of Gastroenterology from October 2 to 7, 1994 in Los Angeles, California, again with scores of presentations and posters on topics ranging from the epidemiology of H pylori infection to steps towards the development of a human vaccine. All this was in addition to important new work presented earlier in 1994 in New Orleans during Digestive Diseases Week. In this digest of these important meetings, the authors will not regurgitate what the informed reader already knows, but will instead focus on the recent developments in important areas, providing selected key published references for background, and referring to this new work in abstract form which is at the cutting edge of “yesterday’s tomorrow today”.

  8. What Is Europe? The Greek Beginnings

    Directory of Open Access Journals (Sweden)

    Piotr Jaroszyński


    Full Text Available The article begins with the statement that there are three concepts of Europe historically significant. The first concept of Europe looms out in the context of the clash between the ancient Greeks and the Persians, the second one is induced by Christianity and Islam meeting head-on whereas the third concept results from the European civilization confronting the cultures of the newly discovered peoples inhabiting other continents. It is just in the context of the indicated clashes that the concept of Europe is shaped as a phenomenon diversified not only geographically but also in terms of civilization as regards other cultures or civilizations. The article then concerns with the concept of Europeanism which in the cultural sense was crystallized in Greece at the turn of the fifth and fourth centuries before Christ. It emerged on the background of the opposition between the Greeks and Asians as well as other peoples, which were referred to as barbarians by the Greeks. The article concludes that it was culture and freedom which constituted two arms of Europeanness shaped by the ancient Greeks.

  9. Sjogren's Syndrome: A Place to Begin

    Medline Plus

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  10. Sjogren's Syndrome: A Place to Begin

    Medline Plus

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  11. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... to Support the SSF Blog: Conquering Sjögren’s SSF Social Network Host an SSF Event SSF Store - Books, CDs & More Faces of Sjögren's Wake Up, Koala! Provider/Researcher Research Grants > Grant Application > Current Recipients > Past Recipients Student ...

  12. Catalysis of heat-to-work conversion in quantum machines (United States)

    Ghosh, A.; Latune, C. L.; Davidovich, L.; Kurizki, G.


    We propose a hitherto-unexplored concept in quantum thermodynamics: catalysis of heat-to-work conversion by quantum nonlinear pumping of the piston mode which extracts work from the machine. This concept is analogous to chemical reaction catalysis: Small energy investment by the catalyst (pump) may yield a large increase in heat-to-work conversion. Since it is powered by thermal baths, the catalyzed machine adheres to the Carnot bound, but may strongly enhance its efficiency and power compared with its noncatalyzed counterparts. This enhancement stems from the increased ability of the squeezed piston to store work. Remarkably, the fraction of piston energy that is convertible into work may then approach unity. The present machine and its counterparts powered by squeezed baths share a common feature: Neither is a genuine heat engine. However, a squeezed pump that catalyzes heat-to-work conversion by small investment of work is much more advantageous than a squeezed bath that simply transduces part of the work invested in its squeezing into work performed by the machine.

  13. Structural basis for catalysis at the membrane-water interface. (United States)

    Dufrisne, Meagan Belcher; Petrou, Vasileios I; Clarke, Oliver B; Mancia, Filippo


    The membrane-water interface forms a uniquely heterogeneous and geometrically constrained environment for enzymatic catalysis. Integral membrane enzymes sample three environments - the uniformly hydrophobic interior of the membrane, the aqueous extramembrane region, and the fuzzy, amphipathic interfacial region formed by the tightly packed headgroups of the components of the lipid bilayer. Depending on the nature of the substrates and the location of the site of chemical modification, catalysis may occur in each of these environments. The availability of structural information for alpha-helical enzyme families from each of these classes, as well as several beta-barrel enzymes from the bacterial outer membrane, has allowed us to review here the different ways in which each enzyme fold has adapted to the nature of the substrates, products, and the unique environment of the membrane. Our focus here is on enzymes that process lipidic substrates. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. From Natural Polysaccharides to Materials for Catalysis, Adsorption, and Remediation (United States)

    Quignard, Françoise; di Renzo, Francesco; Guibal, Eric

    Polysaccharides display most of the properties needed for applications in catalysis, adsorption or remediation. Requisites common to these applications are appropriate surface functions to ensure substrate-material interactions, accessibility of the functional groups, and proper shaping for easy manipulation. Natural polysaccharides are well known as supports for enzymatic catalysts and gelling agents in aqueous phase, due to the high level of dispersion of hydrocolloids. However, they suffer from diffusional limitations in the dry state, due to the low surface area of the dried materials generally used, xerogels or lyophilized solids. This chapter deals with the proper methods to prepare dry materials which retain the dispersion of the polymer hydrogel, namely polysaccharide aerogels. The materials whose properties are described here are stable in most organic solvents and present numerous and diverse surface functionalities (like hydroxy, carboxy, or amino groups). Shaping and appropriate drying of gelling polysaccharides provide a new opportunity to obtain materials from one of the less energy-intensive sources of biomass. Their application in catalysis and adsorption could open substantial markets for products of seaweed harvesting and coproducts of the seafood industry.

  15. Acid-base catalysis of N-[(morpholine)methylene]daunorubicin. (United States)

    Krause, Anna; Jelińska, Anna; Cielecka-Piontek, Judyta; Klawitter, Maria; Zalewski, Przemysław; Oszczapowicz, Irena; Wąsowska, Małgorzata


    The stability of N-[(morpholine)methylene]-daunorubicin hydrochloride (MMD) was investigated in the pH range 0.44-13.54, at 313, 308, 303 and 298 K. The degradation of MMD as a result of hydrolysis is a pseudo-first-order reaction described by the following equation: ln c = ln c(0) - k(obs)• t. In the solutions of hydrochloric acid, sodium hydroxide, borate, acetate and phosphate buffers, k(obs) = k(pH) because general acid-base catalysis was not observed. Specific acid-base catalysis of MMD comprises the following reactions: hydrolysis of the protonated molecules of MMD catalyzed by hydrogen ions (k(1)) and spontaneous hydrolysis of MMD molecules other than the protonated ones (k(2)) under the influence of water. The total rate of the reaction is equal to the sum of partial reactions: k(pH) = k(1) • a(H)+ • f(1) + k(2) • f(2) where: k(1) is the second-order rate constant (mol(-1) l s(-1)) of the specific hydrogen ion-catalyzed degradation of the protonated molecules of MMD; k(2) is the pseudo-first-order rate constant (s(-1)) of the water-catalyzed degradation of MMD molecules other than the protonated ones, f(1) - f(2) are fractions of the compound. MMD is the most stable at approx. pH 2.5.

  16. Graphitic carbon nitride: synthesis, properties, and applications in catalysis. (United States)

    Zhu, Junjiang; Xiao, Ping; Li, Hailong; Carabineiro, Sónia A C


    Graphitic carbon nitride, g-C3N4, is a polymeric material consisting of C, N, and some impurity H, connected via tris-triazine-based patterns. Compared with the majority of carbon materials, it has electron-rich properties, basic surface functionalities and H-bonding motifs due to the presence of N and H atoms. It is thus regarded as a potential candidate to complement carbon in material applications. In this review, a brief introduction to g-C3N4 is given, the methods used for synthesizing this material with different textural structures and surface morphologies are described, and its physicochemical properties are referred. In addition, four aspects of the applications of g-C3N4 in catalysis are discussed: (1) as a base metal-free catalyst for NO decomposition, (2) as a reference material in differentiating oxygen activation sites for oxidation reactions over supported catalysts, (3) as a functional material to synthesize nanosized metal particles, and (4) as a metal-free catalyst for photocatalysis. The reasons for the use of g-C3N4 for such applications are also given, and we expect that this paper will inspire readers to search for further new applications for this material in catalysis and in other fields.

  17. Antibody-Mediated Catalysis in Infection and Immunity. (United States)

    Bowen, Anthony; Wear, Maggie; Casadevall, Arturo


    The existence of catalytic antibodies has been known for decades. Natural antibodies capable of cleaving nucleic acid, protein, and polysaccharide substrates have been described. Although the discovery of catalytic antibodies initially aroused great interest because of their promise for the development of new catalysts, their enzymatic performance has been disappointing due to low reaction rates. However, in the areas of infection and immunity, where processes often occur over much longer times and involve high antibody concentrations, even low catalytic rates have the potential to influence biological outcomes. In this regard, the presence of catalytic antibodies recognizing host antigens has been associated with several autoimmune diseases. Furthermore, naturally occurring catalytic antibodies to microbial determinants have been correlated with resistance to infection. Recently, there has been substantial interest in harnessing the power of antibody-mediated catalysis against microbial antigens for host defense. Additional work is needed, however, to better understand the prevalence, function, and structural basis of catalytic activity in antibodies. Here we review the available information and suggest that antibody-mediated catalysis is a fertile area for study with broad applications in infection and immunity. Copyright © 2017 American Society for Microbiology.

  18. Oxidase catalysis via aerobically generated hypervalent iodine intermediates (United States)

    Maity, Asim; Hyun, Sung-Min; Powers, David C.


    The development of sustainable oxidation chemistry demands strategies to harness O2 as a terminal oxidant. Oxidase catalysis, in which O2 serves as a chemical oxidant without necessitating incorporation of oxygen into reaction products, would allow diverse substrate functionalization chemistry to be coupled to O2 reduction. Direct O2 utilization suffers from intrinsic challenges imposed by the triplet ground state of O2 and the disparate electron inventories of four-electron O2 reduction and two-electron substrate oxidation. Here, we generate hypervalent iodine reagents—a broadly useful class of selective two-electron oxidants—from O2. This is achieved by intercepting reactive intermediates of aldehyde autoxidation to aerobically generate hypervalent iodine reagents for a broad array of substrate oxidation reactions. The use of aryl iodides as mediators of aerobic oxidation underpins an oxidase catalysis platform that couples substrate oxidation directly to O2 reduction. We anticipate that aerobically generated hypervalent iodine reagents will expand the scope of aerobic oxidation chemistry in chemical synthesis.

  19. Role of noble metal nanoparticles in DNA base damage and catalysis: a radiation chemical investigation

    International Nuclear Information System (INIS)

    Sharma, Geeta K.


    In the emerging field of nanoscience and nanotechnology, tremendous focus has been made by researcher to explore the applications of nanomaterials for human welfare by converting the findings into technology. Some of the examples have been the use of nanoparticles in the field of opto-electronic, fuel cells, medicine and catalysis. These wide applications and significance lies in the fact that nanoparticles possess unique physical and chemical properties very different from their bulk precursors. Numerous methods for the synthesis of noble nanoparticles with tunable shape and size have been reported in literature. The goal of our group is to use different methods of synthesis of noble metal nanoparticles (Au, Ag, Pt and Pd) and test their protective/damaging role towards DNA base damage induced by ionizing radiation (Au and Ag) and to test the catalytic activity of nanoparticles (Pt and Pd) in certain known organic synthesis/electron transfer reactions. Using radiation chemical techniques such as pulse radiolysis and steady state radiolysis complemented by the product analysis using HPLC/LC-MS, a detailed mechanism for the formation of transient species, kinetics leading to the formation of stable end products is studied in the DNA base damage induced by ionizing radiation in presence and absence of Au and Ag nanoparticles. Unraveling the complex interaction between catalysts and reactants under operando conditions is a key step towards gaining fundamental insight in catalysis. The catalytic activity of Pt and Pd nanoparticles in electron transfer and Suzuki coupling reactions has been determined. Investigations are currently underway to gain insight into the interaction between catalysts and reactants using time resolved spectroscopic measurements. These studies will be detailed during the presentation. (author)

  20. First Contact: Expectations of Beginning Astronomy Students (United States)

    Lacey, T. L.; Slater, T. F.


    Three hundred seven undergraduate students enrolled in Introductory Astronomy were surveyed at the beginning of class to determine their expectations for course content. The course serves as a survey of astronomy for non-science majors and is a distribution course for general education core requirements. The course has no prerequisites, meets three times each week for 50 minutes, and represents three semester credit hours. The university catalog describes the course with the title "PHYSICS 101 - Mysteries of the Sky" and the official course description is: a survey of the struggle to understand the Universe and our place therein. The structure, growth, methods, and limitations of science will be illustrated using the development of astronomy as a vehicle. Present day views of the Universe are presented. Two questions were asked as open response items: What made you decide to take this course? and What do you expect to learn in this course? The reasons that students cited to take the course, in order of frequency, were: interested in astronomy, interesting or fun sounding course, required general education fulfillment, recommendation by peer. Secondary reasons cited were required for major or minor, general interest in science, and was available in the schedule. Tertiary reasons listed were recommendation by advisor or orientation leader, inflate grade point average, and heard good things about the teacher. The students' expectations about what they would learn in the course were numerous. The most common objects listed, in order of frequency, were: stars, constellations, planets, galaxies, black holes, solar system, comets, galaxies, asteroids, moon, and Sun. More interesting were the aspects not specifically related to astronomy. These were weather, atmosphere, UFOs and the unexplained, generally things in the sky. A mid-course survey suggests that students expected to learn more constellations and that the topics would be less in-depth.

  1. [The beginning of the Cuban demographic revolution]. (United States)

    Hernandez Castellon, R


    The characteristics of the Cuban demographic revolution associated with the main economic, political, and social changes in the country are analyzed. The authors begin with a brief historical outline of the political-economic situation in the country in the middle of the 19th century. There is emphasis on the dependency of the Cuban economy and its monoproducer nature (with sugar being the major export). This was due to the Spanish colonization and to the subsequent American neocolonization. The discovery of the cause for yellow fever by a Cuban physician and the sanitation campaign conducted by the Americans contributed to a diminishing of mortality. A great migratory flow occurred due to the price of sugar in the world market. This must have influenced Cuban demographic patterns which are a major factor linked to the demographic revolution. The influence on proliferation of urbanization and educational trends is emphasized. The low participation in economic activities of women during the early part of the century did affect fertility levels. The trends in mortality throughout the period 1907-43 are pointed out. It was found that 1 major aspect which had a bearing on Cuban demographic patterns was the 2 large migratory flows. An analysis of growth rates in the population--which also confirms the demographic changes in Cuba--is presented. It is concluded that the 4th decade of this century witnessed Cuba's entry in a new stage of the demographic revolution, a stage in which decreased fertility and mortality go together to create a new period. (author's)

  2. Insights into Enzyme Catalysis and Thyroid Hormone Regulation of Cerebral Ketimine Reductase/μ-Crystallin Under Physiological Conditions. (United States)

    Hallen, André; Cooper, Arthur J L; Jamie, Joanne F; Karuso, Peter


    Mammalian ketimine reductase is identical to μ-crystallin (CRYM)-a protein that is also an important thyroid hormone binding protein. This dual functionality implies a role for thyroid hormones in ketimine reductase regulation and also a reciprocal role for enzyme catalysis in thyroid hormone bioavailability. In this research we demonstrate potent sub-nanomolar inhibition of enzyme catalysis at neutral pH by the thyroid hormones L-thyroxine and 3,5,3'-triiodothyronine, whereas other thyroid hormone analogues were shown to be far weaker inhibitors. We also investigated (a) enzyme inhibition by the substrate analogues pyrrole-2-carboxylate, 4,5-dibromopyrrole-2-carboxylate and picolinate, and (b) enzyme catalysis at neutral pH of the cyclic ketimines S-(2-aminoethyl)-L-cysteine ketimine (owing to the complex nomenclature trivial names are used for the sulfur-containing cyclic ketimines as per the original authors' descriptions) (AECK), Δ(1)-piperideine-2-carboxylate (P2C), Δ(1)-pyrroline-2-carboxylate (Pyr2C) and Δ(2)-thiazoline-2-carboxylate. Kinetic data obtained at neutral pH suggests that ketimine reductase/CRYM plays a major role as a P2C/Pyr2C reductase and that AECK is not a major substrate at this pH. Thus, ketimine reductase is a key enzyme in the pipecolate pathway, which is the main lysine degradation pathway in the brain. In silico docking of various ligands into the active site of the X-ray structure of the enzyme suggests an unusual catalytic mechanism involving an arginine residue as a proton donor. Given the critical importance of thyroid hormones in brain function this research further expands on our knowledge of the connection between amino acid metabolism and regulation of thyroid hormone levels.

  3. The Beginning Before the Beginning: Hegel and the Activation of Philosophy

    Directory of Open Access Journals (Sweden)

    Paul Ashton


    Full Text Available This paper suggests that it is not enough to simply account for the lsquo;beginningrsquo; in Hegelrsquo;s philosophy. To capture the speculative depth of Hegelrsquo;s thinking one must also account for the beginning of philosophy as such. That is, how or why the philosopher begins or lsquo;the beginning before the beginningrsquo;. The question of the activation of the philosophical project itself is explored through Hegelrsquo;s notion of the lsquo;need of philosophyrsquo; and the fundamental relation between the historical event of the French Revolution and philosophical thinking. This question is explored through a critical discussion of those thinkers who are also concerned with the philosophy/revolution relation but are critical of Hegelrsquo;s approach. It is suggested that these critical readings employ a thematic approach to both Hegel and philosophy more generally. This approach renders them unable to appreciate Hegelrsquo;s philosophy speculatively and as a consequence the relation between philosophy and freedom, via the revolution, is misconstrued. In contradistinction to these readings the question of how one encounters Hegelrsquo;s thought non-thematically is explored through an analysis of the willingness of the would-be philosopher to activate themselves into the philosophical project and dwell with Hegel in the lsquo;wersquo;. Rather than providing answers to the questions raised, this paper seeks to act as a provocation for a renewed encounter with Hegelrsquo;s philosophy. br /

  4. 34 CFR 75.605 - Beginning the construction. (United States)


    ... 34 Education 1 2010-07-01 2010-07-01 false Beginning the construction. 75.605 Section 75.605... by a Grantee? Construction § 75.605 Beginning the construction. (a) A grantee shall begin work on... working drawings and specifications. (Authority: 20 U.S.C. 1221e-3 and 3474) ...

  5. [Women and HIV/AIDS: stormy beginnings]. (United States)

    Henrion, Roger


    Following the transfusion of a young woman with two units of blood infected by human immunodeficiency virus (HIV) during a Cesarean section performed at the Obstetrics and Gynecology Unit of Port-Royal Hospital in Paris in 1984, the author realized the danger that this virus would represent for women and their children, at a time when the infection seemed to be confined to homosexuals, drug addicts, hemophiliacs and transfusion recipients. He was confronted with a whole series of issues, including the rejection of HIV-positive women; the need for special precautions in the labor room and operating theater; and the need for these patients to be managed in a single center staffed by skilled and willing healthcare professionals who could help them decide whether or not to continue the pregnancy. The main risks at this time were the onset of life-threatening opportunistic infections during pregnancy and HIV transmission to the child (estimated at 20% to 30%). Other thorny issues included the case of couples wishing to have children when either of the two members was infected, and the question of professional confidentiality when an immunocompromised HIV-seropositive husband stubbornly refused to inform his wife or to use condoms. It seemed important to bring these women together, especially those of African origin, within a self-help group where they could express themselves openly and discuss their difficulties. Screening for HIV antibodies in early pregnancy became necessary to permit preventive treatment of mother-child HIV transmission, and to inform pediatricians. There was also a need to estimate and monitor the seroprevalence of HIV among pregnant women, and this was done by conducting a "sentinel" survey that was subsequently taken over by INSERM and the European Centre for the Epidemiological Monitoring of AIDS. After listing many other issues that were hotly debated over the years, the author describes how, at the beginning of the epidemic, new proposals

  6. Beginning a Multidimensional Theory of Creativity (United States)

    Chambers, Jack A.


    Advances 12 hypotheses to answer (1) What is creativity? (2) Why does creative behavior occur? (3) How does it occur? while including theoretical contributions by Freud, Jung, Adler, Rank, neo-Freudians, inter-personal theorists, trait theorists, association theorists and relevant research findings. (MB)

  7. Ancient Phylogenetic Beginnings of Immunoglobulin Hypermutation

    Czech Academy of Sciences Publication Activity Database

    Kubrycht, J.; Sigler, Karel; Růžička, Michal; Souček, P.; Borecký, J.; Ježek, Petr


    Roč. 63, - (2006), s. 691-706 ISSN 0022-2844 Institutional research plan: CEZ:AV0Z50200510; CEZ:AV0Z50110509 Keywords : immunoglobulin * hypermutation * antigen Subject RIV: EE - Microbiology, Virology Impact factor: 2.767, year: 2006

  8. Classroom Management: Beginning Teachers' Perceptions of Preparedness (United States)

    Woods, Sean A.


    Classroom management has been the focal point of many different studies and research projects. Unfortunately, it has also been cited as one of the top three reasons teachers leave the field of education not only today, but for the last 40 years (Berry, 2010). There is a need for an understanding of the implications of past classroom management…

  9. Sjogren's Syndrome: A Place to Begin

    Medline Plus

    Full Text Available ... Patient Seminars History World Sjögren's Day Advocacy > Social Security Disability & Sjögren’s Board of Directors Conflict of Interest ... Fellowships > Student Fellowship Recipients Outstanding Abstract Award Researcher ... Initiatives Healthcare Provider Information > Diagnosis Criteria > Free ...

  10. Heterogeneous Molecular Catalysis of Electrochemical Reactions: Volcano Plots and Catalytic Tafel Plots. (United States)

    Costentin, Cyrille; Savéant, Jean-Michel


    We analyze here, in the framework of heterogeneous molecular catalysis, the reasons for the occurrence or nonoccurrence of volcanoes upon plotting the kinetics of the catalytic reaction versus the stabilization free energy of the primary intermediate of the catalytic process. As in the case of homogeneous molecular catalysis or catalysis by surface-active metallic sites, a strong motivation of such studies relates to modern energy challenges, particularly those involving small molecules, such as water, hydrogen, oxygen, proton, and carbon dioxide. This motivation is particularly pertinent for what concerns heterogeneous molecular catalysis, since it is commonly preferred to homogeneous molecular catalysis by the same molecules if only for chemical separation purposes and electrolytic cell architecture. As with the two other catalysis modes, the main drawback of the volcano plot approach is the basic assumption that the kinetic responses depend on a single descriptor, viz., the stabilization free energy of the primary intermediate. More comprehensive approaches, investigating the responses to the maximal number of experimental factors, and conveniently expressed as catalytic Tafel plots, should clearly be preferred. This is more so in the case of heterogeneous molecular catalysis in that additional transport factors in the supporting film may additionally affect the current-potential responses. This is attested by the noteworthy presence of maxima in catalytic Tafel plots as well as their dependence upon the cyclic voltammetric scan rate.

  11. Induction and mentoring – counselling to sustain beginning teacher in a lifelong professional career

    DEFF Research Database (Denmark)

    Frederiksen, Lisbeth Angela Lunde; Mølgaard, Dorthe Busk; Andersen, Bente Kjeldbjerg


    We present a review-study. Our aim is to analyse the literature pertaining to induction programs and mentoring for beginning teachers. Research question: What are the documented influences of induction programs and mentoring in sustaining beginning teachers in a lifelong professional career...... development? The review is part of a Danish research project named ”Induction programs and mentoring” carried out by Research Centre VIA Profession and Education in collaboration with The Danish Union Of Teachers. The results of the project will provide part of the basis which a Danish model of induction can...

  12. How can we begin to measure recovery?

    Directory of Open Access Journals (Sweden)

    Kenny Paul J


    Full Text Available Abstract Background There is a lack of consensus in the addiction treatment literature regarding the definition of substance abuse "recovery". Methods This study utilized a review of the literature together with a participatory research design to construct a conceptual model of recovery from the perspectives of addiction treatment professionals, those recovering from addictions, and researchers. Results A multidimensional, comprehensive hypothetical model consisting of seven conceptual domains (physical, biomarker, psychological, psychiatric, chemical dependency, family/social, and spiritual is presented. Each domain is operationally defined by identifying reliable and valid instruments that may be used to measure the domain. It is proposed that the conceptual model be tested using confirmatory factor analysis. Conclusions If empirically supported, this conceptual model would validate the hypothesized multidimensional nature of recovery and provide a potential means for assessing recovery in future treatment outcome studies.

  13. Air-tolerant C–C bond formation via organometallic ruthenium catalysis: diverse catalytic pathways involving (C5Me5)Ru or (C5H5)Ru are robust to molecular oxygen

    Czech Academy of Sciences Publication Activity Database

    Severa, Lukáš; Vávra, Jan; Kohoutová, Anna; Čížková, Martina; Šálová, Tereza; Hývl, Jakub; Šaman, David; Pohl, Radek; Adriaenssens, Louis; Teplý, Filip


    Roč. 50, č. 31 (2009), s. 4526-4528 ISSN 0040-4039 Institutional research plan: CEZ:AV0Z40550506 Keywords : ruthenium * organometallic catalysis * [2+2+2] cycloaddition * terminal alkynes Subject RIV: CC - Organic Chemistry Impact factor: 2.660, year: 2009

  14. In Silico Design in Homogeneous Catalysis Using Descriptor Modelling

    Directory of Open Access Journals (Sweden)

    Gadi Rothenberg


    Full Text Available This review summarises the state-of-the-art methodologies used for designinghomogeneous catalysts and optimising reaction conditions (e.g. choosing the right solvent.We focus on computational techniques that can complement the current advances in high-throughput experimentation, covering the literature in the period 1996-2006. The reviewassesses the use of molecular modelling tools, from descriptor models based onsemiempirical and molecular mechanics calculations, to 2D topological descriptors andgraph theory methods. Different techniques are compared based on their computational andtime cost, output level, problem relevance and viability. We also review the application ofvarious data mining tools, including artificial neural networks, linear regression, andclassification trees. The future of homogeneous catalysis discovery and optimisation isdiscussed in the light of these developments.

  15. π Activation of Alkynes in Homogeneous and Heterogeneous Gold Catalysis. (United States)

    Bistoni, Giovanni; Belanzoni, Paola; Belpassi, Leonardo; Tarantelli, Francesco


    The activation of alkynes toward nucleophilic attack upon coordination to gold-based catalysts (neutral and positively charged gold clusters and gold complexes commonly used in homogeneous catalysis) is investigated to elucidate the role of the σ donation and π back-donation components of the Au-C bond (where we consider ethyne as prototype substrate). Charge displacement (CD) analysis is used to obtain a well-defined measure of σ donation and π back-donation and to find out how the corresponding charge flows affect the electron density at the electrophilic carbon undergoing the nucleophilic attack. This information is used to rationalize the activity of a series of catalysts in the nucleophilic attack step of a model hydroamination reaction. For the first time, the components of the Dewar-Chatt-Duncanson model, donation and back-donation, are put in quantitative correlation with the kinetic parameters of a chemical reaction.

  16. Quantum Chemical Modeling of Homogeneous Water Oxidation Catalysis. (United States)

    Liao, Rong-Zhen; Siegbahn, Per E M


    The design of efficient and robust water oxidation catalysts has proven challenging in the development of artificial photosynthetic systems for solar energy harnessing and storage. Tremendous progress has been made in the development of homogeneous transition-metal complexes capable of mediating water oxidation. To improve the efficiency of the catalyst and to design new catalysts, a detailed mechanistic understanding is necessary. Quantum chemical modeling calculations have been successfully used to complement the experimental techniques to suggest a catalytic mechanism and identify all stationary points, including transition states for both O-O bond formation and O 2 release. In this review, recent progress in the applications of quantum chemical methods for the modeling of homogeneous water oxidation catalysis, covering various transition metals, including manganese, iron, cobalt, nickel, copper, ruthenium, and iridium, is discussed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Quantifying the limits of transition state theory in enzymatic catalysis. (United States)

    Zinovjev, Kirill; Tuñón, Iñaki


    While being one of the most popular reaction rate theories, the applicability of transition state theory to the study of enzymatic reactions has been often challenged. The complex dynamic nature of the protein environment raised the question about the validity of the nonrecrossing hypothesis, a cornerstone in this theory. We present a computational strategy to quantify the error associated to transition state theory from the number of recrossings observed at the equicommittor, which is the best possible dividing surface. Application of a direct multidimensional transition state optimization to the hydride transfer step in human dihydrofolate reductase shows that both the participation of the protein degrees of freedom in the reaction coordinate and the error associated to the nonrecrossing hypothesis are small. Thus, the use of transition state theory, even with simplified reaction coordinates, provides a good theoretical framework for the study of enzymatic catalysis. Copyright © 2017 the Author(s). Published by PNAS.

  18. Molecular surface science of heterogeneous catalysis. History and perspective

    International Nuclear Information System (INIS)

    Somorjai, G.A.


    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH 3 synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures

  19. Molecular surface science of heterogeneous catalysis. History and perspective

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.


    A personal account is given of how the author became involved with modern surface science and how it was employed for studies of the chemistry of surfaces and heterogeneous catalysis. New techniques were developed for studying the properties of the surface monolayers: Auger electron spectroscopy, LEED, XPS, molecular beam surface scattering, etc. An apparatus was developed and used to study hydrocarbon conversion reactions on Pt, CO hydrogenation on Rh and Fe, and NH/sub 3/ synthesis on Fe. A model has been developed for the working Pt reforming catalyst. The three molecular ingredients that control catalytic properties are atomic surface structure, an active carbonaceous deposit, and the proper oxidation state of surface atoms. 40 references, 21 figures. (DLC)

  20. Collective synthesis of natural products by means of organocascade catalysis (United States)

    Jones, Spencer B.; Simmons, Bryon; Mastracchio, Anthony; MacMillan, David W. C.


    Organic chemists are now able to synthesize small quantities of almost any known natural product, given sufficient time, resources and effort. However, translation of the academic successes in total synthesis to the large-scale construction of complex natural products and the development of large collections of biologically relevant molecules present significant challenges to synthetic chemists. Here we show that the application of two nature-inspired techniques, namely organocascade catalysis and collective natural product synthesis, can facilitate the preparation of useful quantities of a range of structurally diverse natural products from a common molecular scaffold. The power of this concept has been demonstrated through the expedient, asymmetric total syntheses of six well-known alkaloid natural products: strychnine, aspidospermidine, vincadifformine, akuammicine, kopsanone and kopsinine. PMID:21753848

  1. Catalysis by Dust Grains in the Solar Nebula (United States)

    Kress, Monika E.; Tielens, Alexander G. G. M.


    In order to determine whether grain-catalyzed reactions played an important role in the chemistry of the solar nebula, we have applied our time-dependent model of methane formation via Fischer-Tropsch catalysis to pressures from 10(exp -5) to 1 bar and temperatures from 450 to 650 K. Under these physical conditions, the reaction 3H2 + CO yields CH4 + H2O is readily catalyzed by an iron or nickel surface, whereas the same reaction is kinetically inhibited in the gas phase. Our model results indicate that under certain nebular conditions, conversion of CO to methane could be extremely efficient in the presence of iron-nickel dust grains over timescales very short compared to the lifetime of the solar nebula.

  2. Enantioselective Polyene Cyclization via Organo-SOMO Catalysis (United States)

    Rendler, Sebastian; MacMillan, David W. C.


    The first organocatalytic enantioselective radical polycyclization has been accomplished using singly occupied molecular orbital (SOMO) catalysis. The presented strategy relies on a selective single-electron oxidation of chiral enamines formed by condensation of polyenals with an imidazolidinone catalyst employing a suitable copper(II) oxidant. The reaction proceeds under mildly acidic conditions at room temperature and shows compatibility with an array of electron-poor as well as electron-rich functional groups. Upon termination by radical arylation, followed by subsequent oxidation and rearomatization, a range of polycyclic aldehydes has been accessed (12 examples, 54-77% yield, 85-93% ee). The enantioselective formation of up to six new carbocycles in a single catalyst-controlled cascade is described. Evidence for a radical-based cascade mechanism is indicated by a series of experimental results. PMID:20334384

  3. Cooperative catalysis with block copolymer micelles: A combinatorial approach

    KAUST Repository

    Bukhryakov, Konstantin V.


    A rapid approach to identifying complementary catalytic groups using combinations of functional polymers is presented. Amphiphilic polymers with "clickable" hydrophobic blocks were used to create a library of functional polymers, each bearing a single functionality. The polymers were combined in water, yielding mixed micelles. As the functional groups were colocalized in the hydrophobic microphase, they could act cooperatively, giving rise to new modes of catalysis. The multipolymer "clumps" were screened for catalytic activity, both in the presence and absence of metal ions. A number of catalyst candidates were identified across a wide range of model reaction types. One of the catalytic systems discovered was used to perform a number of preparative-scale syntheses. Our approach provides easy access to a range of enzyme-inspired cooperative catalysts.

  4. Catalysis and Sulfa Drug Resistance in Dihydropteroate Synthase

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Mi-Kyung; Wu, Yinan; Li, Zhenmei; Zhao, Ying; Waddell, M. Brett; Ferreira, Antonio M.; Lee, Richard E.; Bashford, Donald; White, Stephen W. (SJCH)


    The sulfonamide antibiotics inhibit dihydropteroate synthase (DHPS), a key enzyme in the folate pathway of bacteria and primitive eukaryotes. However, resistance mutations have severely compromised the usefulness of these drugs. We report structural, computational, and mutagenesis studies on the catalytic and resistance mechanisms of DHPS. By performing the enzyme-catalyzed reaction in crystalline DHPS, we have structurally characterized key intermediates along the reaction pathway. Results support an S{sub N}1 reaction mechanism via formation of a novel cationic pterin intermediate. We also show that two conserved loops generate a substructure during catalysis that creates a specific binding pocket for p-aminobenzoic acid, one of the two DHPS substrates. This substructure, together with the pterin-binding pocket, explains the roles of the conserved active-site residues and reveals how sulfonamide resistance arises.

  5. Value-added Chemicals from Biomass by Heterogeneous Catalysis

    DEFF Research Database (Denmark)

    Voss, Bodil

    been implemented. The subject on chemical production has received less attention. This thesis describes and evaluates the quest for an alternative conversion route, based on a biomass feedstock and employing a heterogeneous catalyst capable of converting the feedstock, to a value-added chemical...... obtained for such a process and the hypothesis that process feasibility in comparison with the conventional synthesis gas based technologies may further be attainable, taking advantage of the conservation of chemical C-C bonds in biomass based feedstocks. With ethanol as one example of a biomass based...... feedstock, having retained one C-C bond originating from the biomass precursor, the aspects of utilising heterogeneous catalysis for its conversion to value added chemicals is investigated. Through a simple analysis of known, but not industrialised catalytic routes, the direct conversion of ethanol...

  6. Vanadium-modified molecular sieves: preparation, characterization and catalysis

    Directory of Open Access Journals (Sweden)

    Ângela A. Teixeira-Neto


    Full Text Available Vanadium-containing molecular sieves are redox catalysts and are good candidates as substitutes for oxide-supported V2O5 in a number of reactions. These materials have the advantage of presenting better dispersion of vanadium species, as well as shape-selective properties and controllable acidities. They may be prepared by one-pot synthesis or by post-synthesis methods and a number of techniques such as diffuse reflectance UV-visible spectroscopy, 51V nuclear magnetic resonance and electron paramagnetic resonance, to name but a few, have been used to characterize these materials. In this review, methods of preparation of vanadium-modified molecular sieves, their characterization and applications in catalysis are discussed.

  7. Kinetic compensation and the role of cations in pectinesterase catalysis. (United States)

    Sun, D; Wicker, L


    The catalytic rate constant of thermostable pectinesterase (TS-PE) from Marsh grapefruit pulp was determined at pH 7 at temperatures between 25 and 60 degrees C. TS-PE activity was measured at NaCl concentrations of 0.05, 0.10, 0.15, and 0.20 M and at CaCl(2) concentrations of 0.005, 0.010, 0.015, and 0.020 M. For sodium- and calcium-added conditions, the kinetic functions of this reaction agreed with kinetic compensation relations. The isokinetic temperatures for sodium- and calcium-added conditions were 327.8 and 312.4 K, respectively. Different isokinetic temperatures and compensation parameters suggest that sodium and calcium uniquely affect TS-PE catalysis. This is the first demonstration of kinetic compensation in an enzyme-catalyzed reaction.

  8. A solvable two-species catalysis-driven aggregation model

    CERN Document Server

    Ke Jian Hong


    We study the kinetics of a two-species catalysis-driven aggregation system, in which an irreversible aggregation between any two clusters of one species occurs only with the catalytic action of another species. By means of a generalized mean-field rate equation, we obtain the asymptotic solutions of the cluster mass distributions in a simple process with a constant rate kernel. For the case without any consumption of the catalyst, the cluster mass distribution of either species always approaches a conventional scaling law. However, the evolution behaviour of the system in the case with catalyst consumption is complicated and depends crucially on the relative data of the initial concentrations of the two species.

  9. Microfabricated reactors for on-chip heterogeneous catalysis. (United States)

    McCreedy, T; Wilson, N G


    Microfabricated devices constructed from glass and polydimethylsiloxane with integral heaters are described, which can be used for heterogeneous catalysis reactions. Sulfated zirconia is used as the catalyst in an open channel reactor, with either a syringe pump or electroosmotic flow being used to deliver the reactants. The results clearly demonstrate that very high conversion efficiencies are possible, however, the thermodynamics of the reactions are the same as in bulk systems. Ethanol and hexanol are dehydrated to ethene and hexene, respectively, with conversion efficiencies approaching 100%, and the esterification of ethanol is investigated. Yields of approximately 30% ethyl acetate are obtained by gas chromatographic analysis. This is the first time such a method for fabricating a catalyst micro reactor has been reported, yet it demonstrates sufficient robustness and resistance to leakage. The use of electroosmotic flow in a heated catalyst reactor is a significant advancement in reactor design.

  10. Metal Carbonyl-Hydrosilane Reactions and Hydrosilation Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, A. R.


    Manganese carbonyl complexes serve as hydrosilation precatalysts for selectively transforming a carbonyl group into a siloxy methylene or a fully reduced methylene group. Substrates of interest include (1) aldehydes, ketones, carboxylic acids, silyl esters, and esters, and (2) their organometallic acyl counterparts. Three relevant catalytic reactions are shown. Two types of manganese precatalysts have been reported: (a) alkyl and acyl complexes (L)(C0){sub 4}MnR [L = CO, PPh{sub 3}; R = COCH{sub 3}, COPh, CH{sub 3}] and (b) halides (CO){sub 5}MnX and [(CO){sub 4}MnX]{sub 2} (X = Br, I). The former promote hydrosilation and deoxygenation catalysis; the latter promote dehydrogenative silation of alcohols and carboxylic acids as well as hydrosilation and deoxygenation of some metallocarboxylic acid derivatives. In every case studied, these Mn precatalysts are far more reactive or selective than traditional Rh(I) precatalysts.

  11. Mesostructure-Induced Selectivity in CO2 Reduction Catalysis. (United States)

    Hall, Anthony Shoji; Yoon, Youngmin; Wuttig, Anna; Surendranath, Yogesh


    Gold inverse opal (Au-IO) thin films are active for CO2 reduction to CO with high efficiency at modest overpotentials and high selectivity relative to hydrogen evolution. The specific activity for hydrogen evolution diminishes by 10-fold with increasing porous film thickness, while CO evolution activity is largely unchanged. We demonstrate that the origin of hydrogen suppression in Au-IO films stems from the generation of diffusional gradients within the pores of the mesostructured electrode rather than changes in surface faceting or Au grain size. For electrodes with optimal mesoporosity, 99% selectivity for CO evolution can be obtained at overpotentials as low as 0.4 V. These results establish electrode mesostructuring as a complementary method for tuning selectivity in CO2-to-fuels catalysis.

  12. Gravitational catalysis of merons in Einstein-Yang-Mills theory (United States)

    Canfora, Fabrizio; Oh, Seung Hun; Salgado-Rebolledo, Patricio


    We construct regular configurations of the Einstein-Yang-Mills theory in various dimensions. The gauge field is of meron-type: it is proportional to a pure gauge (with a suitable parameter λ determined by the field equations). The corresponding smooth gauge transformation cannot be deformed continuously to the identity. In the three-dimensional case we consider the inclusion of a Chern-Simons term into the analysis, allowing λ to be different from its usual value of 1 /2 . In four dimensions, the gravitating meron is a smooth Euclidean wormhole interpolating between different vacua of the theory. In five and higher dimensions smooth meron-like configurations can also be constructed by considering warped products of the three-sphere and lower-dimensional Einstein manifolds. In all cases merons (which on flat spaces would be singular) become regular due to the coupling with general relativity. This effect is named "gravitational catalysis of merons".

  13. Atomically precise cluster catalysis towards quantum controlled catalysts

    International Nuclear Information System (INIS)

    Watanabe, Yoshihide


    Catalysis of atomically precise clusters supported on a substrate is reviewed in relation to the type of reactions. The catalytic activity of supported clusters has generally been discussed in terms of electronic structure. Several lines of evidence have indicated that the electronic structure of clusters and the geometry of clusters on a support, including the accompanying cluster-support interaction, are strongly correlated with catalytic activity. The electronic states of small clusters would be easily affected by cluster–support interactions. Several studies have suggested that it is possible to tune the electronic structure through atomic control of the cluster size. It is promising to tune not only the number of cluster atoms, but also the hybridization between the electronic states of the adsorbed reactant molecules and clusters in order to realize a quantum-controlled catalyst. (review)

  14. Advances in Nucleophilic Phosphine Catalysis of Alkenes, Allenes, Alkynes, and MBHADs (United States)

    Fan, Yi Chiao


    In nucleophilic phosphine catalysis, tertiary phosphines undergo conjugate additions to activated carbon–carbon multiple bonds to form β-phosphonium enolates, β-phosphonium dienolates, β-phosphonium enoates, and vinyl phosphonium ylides as intermediates. When these reactive zwitterionic species react with nucleophiles and electrophiles, they may generate carbo- and heterocycles with multifarious molecular architectures. This Article describes the reactivities of these phosphonium zwitterions, the applications of phosphine catalysis in the syntheses of biologically active compounds and natural products, and recent developments in the enantioselective phosphine catalysis. PMID:24196409

  15. Like a Chameleon: A Beginning Teacher's Journey to Implement Active Learning (United States)

    Edwards, Susan


    The purpose of this study was to follow the learning trajectory of a beginning teacher attempting to implement active learning instructional methods in a middle grades classroom. The study utilized a qualitative case study methodological approach with the researcher in the role of participant observer. Three research questions were explored: the…

  16. Aspiring Principals' Perception of the Challenges of Beginning Principals and the Support That They Need (United States)

    Ng, Pak Tee


    This paper presents the results of an exploratory research project about the perception of aspiring principals regarding the challenges of beginning principals and the support that they need. These aspiring principals are participants on the Leaders in Education Programme (LEP) in Singapore. According to the research findings, the LEP participants…

  17. Factors Influencing Beginning Teacher Retention in the Diocese of St. Augustine Catholic Schools (United States)

    Bronsard, Patricia


    Researchers explored the problem of teacher retention, especially among beginning teachers, and noted a lack of consensus on why teachers leave teaching and how to retain the teachers. Private school studies include Catholic school data, but few researchers isolated the data or used data-gathering instruments to examine Catholic school issues,…

  18. In the beginning was the other

    DEFF Research Database (Denmark)

    Hyldgaard, Kirsten


    In much of educational philosophy and sciences the fundamental concepts are the subject conceived of as conscious and constituting and the learning process conceived of as a matter of cognition. This article asks what the effect would be on educational research method and educational theory...... in general if the fundamental concept were the subject in the sense of the psychoanalytic subject of the unconscious. The aim of the article is not a critique of any sound scientific effort to supply evidence for what can count as best practice and which methods would increase school effectiveness. Rather...

  19. Begin your partnership: the process of engagement. (United States)

    Jones, Loretta; Meade, Barbara; Forge, Nell; Moini, Moraya; Jones, Felica; Terry, Chrystene; Norris, Keith


    Community Partnered-Participatory Research (CPPR) is based on and utilizes community engagement as its central method and principle. In this chapter, we explain the key differences between engaging the community vs merely involving the community. The chapter also reviews the plan-do-action cycle of work that is used in each stage of CPPR. We define five key values of CPPR: respect for diversity, openness, equality, redirected power (empowerment), and an asset-based approach. In addition, we present 12 operational principles, which guide work throughout every stage of all CPPR initiatives.

  20. Catalysis Science Initiative: Catalyst Design by Discovery Informatics

    Energy Technology Data Exchange (ETDEWEB)

    Delgass, William Nicholas [Purdue Univ., West Lafayette, IN (United States). Chemical Engineering; Abu-Omar, Mahdi [Purdue Univ., West Lafayette, IN (United States) Department of Chemistry; Caruthers, James [Purdue Univ., West Lafayette, IN (United States). Chemical Engineering; Ribeiro, Fabio [Purdue Univ., West Lafayette, IN (United States). Chemical Engineering; Thomson, Kendall [Purdue Univ., West Lafayette, IN (United States). Chemical Engineering; Schneider, William [Univ. of Notre Dame, IN (United States)


    Catalysts selectively enhance the rates of chemical reactions toward desired products. Such reactions provide great benefit to society in major commercial sectors such as energy production, protecting the environment, and polymer products and thereby contribute heavily to the country’s gross national product. Our premise is that the level of fundamental understanding of catalytic events at the atomic and molecular scale has reached the point that more predictive methods can be developed to shorten the cycle time to new processes. The field of catalysis can be divided into two regimes: heterogeneous and homogeneous. For the heterogeneous catalysis regime, we have used the water-gas shift (WGS) reaction (CO + H2O + CO2 + H2O) over supported metals as a test bed. Detailed analysis and strong coupling of theory with experiment have led to the following conclusions: • The sequence of elementary steps goes through a COOH intermediate • The CO binding energy is a strong function of coverage of CO adsorbed on the surface in many systems • In the case of Au catalysts, the CO adsorption is generally too weak on surface with close atomic packing, but the enhanced binding at corner atoms (which are missing bonding partners) of cubo-octahedral nanoparticles increases the energy to a near optimal value and produces very active catalysts. • Reaction on the metal alone cannot account for the experimental results. The reaction is dual functional with water activation occurring at the metal-support interface. It is clear from our work that the theory component is essential, not only for prediction of new systems, but also for reconciling data and testing hypotheses regarding potential descriptors. Particularly important is the finding that the interface between nano-sized metal particles and the oxides that are used to support them represent a new state of matter in the sense that the interfacial bonding perturbs the chemical state of both metals atoms and the support