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Sample records for applied electrochemistry prikladnaya

  1. Electrochemistry applied to biomass. Progress report, October 1980-September 1981

    Energy Technology Data Exchange (ETDEWEB)

    Chum, H. L. [ed.

    1982-04-01

    The electrochemical conversion of biomass-derived compounds, obtained through thermochemical pretreatments, into valuable organic chemicals, petrochemical substitutes, and energy-intensive chemicals is investigated. A hardwood-derived lignin obtained from ethanol extraction of the explosively depressurized aspen has been investigated. We have partially characterized this lignin material, and have also submitted it to electrolyses under controlled potential. The electrolytic conditions employed so far affect mainly the carbonyl groups of the ethanol-extracted steam-exploded aspen lignin. We have some evidence of demethoxylation and changed phenolic content after electrolysis. During product isolation, fractionation of the lignin occurs. The material with decreased methoxyl content may be suitable to replace phenol in phenol-formaldehyde-type resins. We are continuing these electrochemical and chemical investigations. Gel-permeation chromatography is being used to separate and characterize the several lignin fractions. In addition, we are carrying out electrolyses under more powerful reducing conditions which may lead to the cleavage of the main bonds in the lignin molecule (the ..beta..-0-4 ether linkages) producing monomeric and dimeric phenolic compounds. The electrochemistry and photoelectrochemistry of levulinic (4-oxo-pentanoic) acid, the major product of controlled degradation of cellulose by acids, have been investigated. This acid can be viewed as a major product of biomass thermochemical pretreatment or as a by-product of acid hydrolysis to fermentable sugars. Since this acid can be present in waste streams of biomass processing, we investigated the photoelectrochemical reactions of this acid on slurries composed of semiconductor/metal particles. The semiconductor investigated was undoped n-TiO/sub 2/, as anatase, anatase-rutile mixture, or rutile.

  2. Investigation of the Interface between Two Immiscible Electrolytes Applied to Membrane Electrochemistry

    Science.gov (United States)

    1988-10-13

    potentiometry were used. The results provided more insight in interfacial potential behavior. The contribution -,as particularly significant in providing large...Electrochemistry of oxacyanine dyes: Potentiometry on liquid/liquid interface. Atlanta Electrochemical Society Meeting May 1988. TRAINING: Two graduate students

  3. Encyclopedia of electrochemistry. Vol. 5. Electrochemical engineering

    Energy Technology Data Exchange (ETDEWEB)

    Bard, A.J. [Texas Univ., Austin, TX (United States). Dept. of Chemistry; Stratmann, M. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany); Macdonald, D. [Pennsylvania State Univ., University Park, PA (United States). Center for Electrochemical Science and Engineering; Schmuki, P. (eds.) [Erlangen-Nuernberg Univ., Erlangen (Germany). Dept. of Material Science

    2007-07-01

    This volume contains the following chapters: 1. Technical scale of electrochemistry; 2. Electrocatalysis; 3. Electrochemical composition; 4. Electrowinning of metals; 5. Electrowinning of other inorganic compounds; 6. Electrochemistry applied to organic synthesis: Principles and main achievements; 7. Batteries: Basic principles, technologies, and modeling; 8. Fuel cells; 9. The electrochemistry of nuclear reactor coolant circuits; 10. Electrochemical techniques for studying high-temperature subcritical and supercritical aqueous solutions; 11. Electrochemistry of silicon etching; 12. Electrochemical machining; 13. Environmental chemistry.

  4. Analytical and physical electrochemistry

    CERN Document Server

    Girault, Hubert H

    2004-01-01

    The study of electrochemistry is pertinent to a wide variety of fields, including bioenergetics, environmental sciences, and engineering sciences. In addition, electrochemistry plays a fundamental role in specific applications as diverse as the conversion and storage of energy and the sequencing of DNA.Intended both as a basic course for undergraduate students and as a reference work for graduates and researchers, Analytical and Physical Electrochemistry covers two fundamental aspects of electrochemistry: electrochemistry in solution and interfacial electrochemistry. By bringing these two subj

  5. Applied Electrochemistry of Aluminum

    DEFF Research Database (Denmark)

    Li, Qingfeng; Qiu, Zhuxian

    electrolytes. The book is an updated review of the technological advances in the fields of electrolytic production and refining of metals, electroplating, anodizing and other electrochemical surface treatments, primary and secondary batteries, electrolytic capacitors; corrosion and protection and others....

  6. Applications of electrochemistry and nanotechnology in biology and medicine II

    CERN Document Server

    Eliaz, Noam

    2011-01-01

    The study of electrochemical nanotechnology has emerged as researchers apply electrochemistry to nanoscience and nanotechnology. These two related volumes in the Modern Aspects of Electrochemistry Series review recent developments and breakthroughs in the specific application of electrochemistry and nanotechnology to biology and medicine. Internationally renowned experts contribute chapters that address both fundamental and practical aspects of several key emerging technologies in biomedicine, such as the processing of new biomaterials, biofunctionalization of surfaces, characterization of bio

  7. 关于应用电化学课程的科研化教学思考%A Reflection of Integrating Teaching into Scientific Research for Applied Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    崔萍; 彭荣; 石小鹏; 肖作安

    2015-01-01

    Applied electrochemistry was one of the specialized optional courses for the undergraduate students on chemistry, involving the electrochemical principals and the applications of electrochemistry. A teaching method of integrating teaching into research was employed for applied electrochemistry course. Appling the discipline progress and scientific achievements of teachers in the teaching plan and guiding the students to participate in scientific research practice could make the students’ knowledge more systematic and broadening the students’ vision and knowledge. The innovation ability and scientific research quality can be strengthened by understanding the research methods and achievements.%《应用电化学》是化学专业本科生的专业选修课,主要涉及电化学基本原理以及电化学在各领域的应用。本文介绍了应用电化学课程的科研化教学方法。主要采用将学科科研发展、教师科研成果引入课堂教学,引导学生参与课外科研实践活动的教学模式,开阔学生的视野,增加学生的知识面,使学生的科研素质和综合能力得到提高。

  8. Silicon: electrochemistry and luminescence

    NARCIS (Netherlands)

    Kooij, Ernst Stefan

    2001-01-01

    The electrochemistry of crystalline and porous silicon and the luminescence from porous silicon has been studied. One chapter deals with a model for the anodic dissolution of silicon in HF solution. In following chapters both the electrochemistry and various ways of generating visible luminescenc

  9. Instrumental methods in electrochemistry

    CERN Document Server

    Pletcher, D; Peat, R

    2010-01-01

    Using 372 references and 211 illustrations, this book underlines the fundamentals of electrochemistry essential to the understanding of laboratory experiments. It treats not only the fundamental concepts of electrode reactions, but also covers the methodology and practical application of the many versatile electrochemical techniques available.Underlines the fundamentals of electrochemistry essential to the understanding of laboratory experimentsTreats the fundamental concepts of electrode reactionsCovers the methodology and practical application of the many ve

  10. Nanomaterials in Electrochemistry

    Science.gov (United States)

    2007-11-02

    of the polymer. 46. C. R. Martin, D. T. Mitchell, and J. C. Hulteen, Anal. Chem., Submitted. 47. D. Linden , Handbook of Batteries t2ndV New York...nanoparticles of Li+-intercalation materials for possible use as electrodes in Li-ion batteries . 14. Subject terms: Nanomaterials, electrochemistry...for possible use as electrodes in Li+ batteries . II. Ensembles of Nanoscopic Electrodes. Electrochemistry at electrodes with nanoscopic dimensions

  11. Applications of electrochemistry in medicine

    CERN Document Server

    Schlesinger, Mordechay

    2013-01-01

    Medical Applications of Electrochemistry, a volume of the series Modern Aspects of Electrochemistry, illustrates the interdisciplinary nature of modern science by indicating the many current issues in medicine that are susceptible to solution by electrochemical methods. This book also suggests how personalized medicine can develop.

  12. Electrochemistry in supercritical fluids.

    Science.gov (United States)

    Branch, Jack A; Bartlett, Philip N

    2015-12-28

    A wide range of supercritical fluids (SCFs) have been studied as solvents for electrochemistry with carbon dioxide and hydrofluorocarbons (HFCs) being the most extensively studied. Recent advances have shown that it is possible to get well-resolved voltammetry in SCFs by suitable choice of the conditions and the electrolyte. In this review, we discuss the voltammetry obtained in these systems, studies of the double-layer capacitance, work on the electrodeposition of metals into high aspect ratio nanopores and the use of metallocenes as redox probes and standards in both supercritical carbon dioxide-acetonitrile and supercritical HFCs.

  13. Dynamic Electrochemistry: Methodology and Applications.

    Science.gov (United States)

    Johnson, Dennis C.; And Others

    1984-01-01

    Reviews literature dealing with novel developments or important trends in electrochemistry. Areas examined include mass transfer, electrode kinetics, surface effects, chemically modified electrodes, coulostatic/galvanostatic methods, bioelectrochemistry, spectroelectrochemistry, and electrode instrumentation. Books, textbooks, and literature…

  14. Physical electrochemistry of nanostructured devices.

    Science.gov (United States)

    Bisquert, Juan

    2008-01-07

    This Perspective reviews recent developments in experimental techniques and conceptual methods applied to the electrochemical properties of metal-oxide semiconductor nanostructures and organic conductors, such as those used in dye-sensitized solar cells, high-energy batteries, sensors, and electrochromic devices. The aim is to provide a broad view of the interpretation of electrochemical and optoelectrical measurements for semiconductor nanostructures (sintered colloidal particles, nanorods, arrays of quantum dots, etc.) deposited or grown on a conducting substrate. The Fermi level displacement by potentiostatic control causes a broad change of physical properties such as the hopping conductivity, that can be investigated over a very large variation of electron density. In contrast to traditional electrochemistry, we emphasize that in nanostructured devices we must deal with systems that depart heavily from the ideal, Maxwell-Boltzmann statistics, due to broad distributions of states (energy disorder) and interactions of charge carriers, therefore the electrochemical analysis must be aided by thermodynamics and statistical mechanics. We discuss in detail the most characteristic densities of states, the chemical capacitance, and the transport properties, specially the chemical diffusion coefficient, mobility, and generalized Einstein relation.

  15. Determination of Lead by Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    HE YuFeng; ZHANG Zhang; MA YongJun; KANG JingWan

    2001-01-01

    @@ Lead is one of the poisonous trace element for human body. It is important to find a way for measuring content of lead. Deternination of lead by electrochemistry is one of a method[1]. In this paper, lead is determined by single-sweep polarography. The absorption behavior of meso-tetra (4-sulfonylphenyl) porphyrin (H2TPPS4) complex with lead ion has also been studied.In Na2B4O7-NaOH solution with pH=l 0.5, the reduction peaks of the ligand are P1 (Ep1=-0.38V), P2 (Ep2=-1.04V), which potentials are obtained vs. S.C.E. When lead ion has been added into above solution. The peak current of P1 and P2 decrease, and a new reduction peak P3 (Ep3=-1.10 V) appears. It shows that the TPPS4-Pb(Ⅱ) complex forms,and this method can be applied to study the complex.

  16. Determination of Lead by Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    HE; YuFeng

    2001-01-01

    Lead is one of the poisonous trace element for human body. It is important to find a way for measuring content of lead. Deternination of lead by electrochemistry is one of a method[1]. In this paper, lead is determined by single-sweep polarography. The absorption behavior of meso-tetra (4-sulfonylphenyl) porphyrin (H2TPPS4) complex with lead ion has also been studied.In Na2B4O7-NaOH solution with pH=l 0.5, the reduction peaks of the ligand are P1 (Ep1=-0.38V), P2 (Ep2=-1.04V), which potentials are obtained vs. S.C.E. When lead ion has been added into above solution. The peak current of P1 and P2 decrease, and a new reduction peak P3 (Ep3=-1.10 V) appears. It shows that the TPPS4-Pb(Ⅱ) complex forms,and this method can be applied to study the complex.……

  17. Fundamentals and applications of electrochemistry

    Directory of Open Access Journals (Sweden)

    McEvoy A. J.

    2013-06-01

    Full Text Available The Voltaic pile, invented here on Lake Como 200 years ago, was a crucial step in the development of electrical engineering. For the first time a controlled and reliable source of electric current was available. The science of electrochemistry developed rapidly and is now a key contributor, not just to energy technology but also, for example, to metallurgy and industrial processes. The basic concepts of electrochemistry are presented, with the practical examples of its application in fuel cells, and with the perspective of the history of the subject.

  18. Fundamentals and applications of electrochemistry

    Science.gov (United States)

    McEvoy, A. J.

    2013-06-01

    The Voltaic pile, invented here on Lake Como 200 years ago, was a crucial step in the development of electrical engineering. For the first time a controlled and reliable source of electric current was available. The science of electrochemistry developed rapidly and is now a key contributor, not just to energy technology but also, for example, to metallurgy and industrial processes. The basic concepts of electrochemistry are presented, with the practical examples of its application in fuel cells, and with the perspective of the history of the subject.

  19. Electrochemistry and environment; Electroquimica y Medio Ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Garcia, J.; Iniesta, J.; Agullo, E.; Garcia, V.; Montiel, V.; Aldaz, A. [Grupo de Electroquimica aplicada, Departamento de Quimica y Fisica, Universidad de Alicante, Alicante (Spain)

    1996-09-01

    This paper proposes Electrochemistry as a new technology for waste water treatment. Many advantages and new scopes are described. It also introduces several concepts of Electrochemical Technology. (Author)

  20. Electrochemistry of folded graphene edges.

    Science.gov (United States)

    Ambrosi, Adriano; Bonanni, Alessandra; Pumera, Martin

    2011-05-01

    There is enormous interest in the investigation of electron transfer rates at the edges of graphene due to possible energy storage and sensing applications. While electrochemistry at the edges and the basal plane of graphene has been studied in the past, the new frontier is the electrochemistry of folded graphene edges. Here we describe the electrochemistry of folded graphene edges and compare it to that of open graphene edges. The materials were characterized in detail by high-resolution transmission electron microscopy, Raman spectroscopy, high-resolution X-ray photoelectron spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry. We found that the heterogeneous electron transfer rate is significantly lower on folded graphene edges compared to open edge sites for ferro/ferricyanide, and that electrochemical properties of open edges offer lower potential detection of biomarkers than the folded ones. It is apparent, therefore, that for sensing and biosensing applications the folded edges are less active than open edges, which should then be preferred for such applications. As folded edges are the product of thermal treatment of multilayer graphene, such thermal procedures should be avoided when fabricating graphene for electrochemical applications.

  1. Electrochemistry and Spectroelectrochemistry of Luminescent Europium Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Lines, Amanda M. [Department of Chemistry, Washington State University, Pullman WA 99163; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99352; Wang, Zheming [E Directorate, Pacific Northwest National Laboratory, Richland WA 99352; Clark, Sue B. [Department of Chemistry, Washington State University, Pullman WA 99163; Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99352; Bryan, Samuel A. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland WA 99352

    2016-05-04

    Fast, cost effective, and robust means of detecting and quantifying lanthanides are needed for supporting more efficient tracking within the nuclear, medicinal, and industrial fields. Spectroelectrochemistry (SEC) is a powerful technique combining electrochemistry and spectroscopy that can meet those needs. The primary limitation of SEC as a detection method for lanthanides is their low molar absorptivity in absorbance based measurements and low emission intensities in fluorescence based measurements; both lead to high limits of detection. These limitations can be circumvented by complexing the lanthanides with sensitizing ligands that enhance fluorescence, thereby dropping the limits of detection. Complexation may also stabilize the metal ions in solution and improve the electrochemical reversibility, or Nernstian behavior, of the redox couples. To demonstrate this concept, studies were completed using europium in complexes with four different sensitizing ligands. Initial work indicates Eu in the four complexes studied does display the necessary characteristics for SEC analysis, which was successfully and reproducibly applied to all Eu complexes.

  2. Bacterial biofilms investigated by atomic force microscopy and electrochemistry

    DEFF Research Database (Denmark)

    Hu, Yifan

    thesis, Atomic Force Microscopy (AFM) and electrochemistry have been applied to investigate three pathogenic medically important bacterial biofilms, i.e. Pseudomonas aeruginosa (cystic fibrosis pneumonia), Staphylococcus epidermidis (contamination of surgical catheters and indwelling equipment...... attachment on the surface. High-resolution AFM imaging showed no detectable differences among the four strains. Adhesion maps using hydrophobically modified tips compared with bare hydrophilic silicon nitride tips also showed small differences only. This indicates that hydrophobic effects are not the primary...

  3. Biomass electrochemistry : from cellulose to sorbitol

    NARCIS (Netherlands)

    Kwon, Youngkook

    2013-01-01

    The primary goal of this thesis is to study the potential role of electrochemistry in finding new routes for sustainable chemicals from biomass in aqueous-phase solutions. In order to assess the potential of electrochemistry in biomass conversion, we developed an online HPLC system by using a fracti

  4. Modern Aspects of Electrochemistry 40

    CERN Document Server

    White, Ralph E

    2007-01-01

    This volume in the acclaimed series Modern Aspects of Electrochemistry starts with a dedication to the late Professor Brian Conway who for 50 years helped to guide this series to its current prominence. The remainder of the volume is then devoted to the following topics: PEM fuel cells; the use of graphs in electrochemical reaction newtworks; nanomaterials in Lithium-ion batteries; direct methanolf fuel cells (two chapters); fuel cell catalyst layers. The book is for electrochemists, electrochemical engineers, fuel cell workers and energy generation workers.

  5. Medicinal electrochemistry: integration of electrochemistry, medicinal chemistry and computational chemistry.

    Science.gov (United States)

    Almeida, M O; Maltarollo, V G; de Toledo, R A; Shim, H; Santos, M C; Honorio, K M

    2014-01-01

    Over the last centuries, there were many important discoveries in medicine that were crucial for gaining a better understanding of several physiological processes. Molecular modelling techniques are powerful tools that have been successfully used to analyse and interface medicinal chemistry studies with electrochemical experimental results. This special combination can help to comprehend medicinal chemistry problems, such as predicting biological activity and understanding drug action mechanisms. Electrochemistry has provided better comprehension of biological reactions and, as a result of many technological improvements, the combination of electrochemical techniques and biosensors has become an appealing choice for pharmaceutical and biomedical analyses. Therefore, this review will briefly outline the present scope and future advances related to the integration of electrochemical and medicinal chemistry approaches based on various applications from recent studies.

  6. Electrochemistry "Discovery" Course for Undergraduates

    Science.gov (United States)

    May, Michael Alan; Gupta, Vijay K.

    1997-07-01

    We developed a chemistry selected topics course at Central State University, "Introduction to Laboratory Techniques in Electrochemistry" to: (1) give undergraduates hands-on experience with electrochemical measurements, (2) prepare students for summer research in Fuel Cell and Battery technology. Since students "learn by doing", the course is suitable for undergraduates from sophomore to senior levels. Students complete 6 laboratories, based on a "less is more" philosophy which emphasizes analytic and creative process rather than mandatory topical coverage. Eight electrochemical experiments are available: Construction of Zinc-Copper battery stacks, Lead Acid Battery discharge-charge cycles, Conductimetric titration of aspirin with Ammonium Hydroxide, Ion Selective Electrode determination of Fluoride in water, Cyclic Voltammetry of Potassium Ferricyanide solution, Cyclic Voltammetry of Sulfuric acid on Platinum working electrode, Anodic Stripping Voltammetry of Lead ion in solution, Differential Pulse Polarography of Lead ion in solution. Topics discussed in lecture include: chemical definitions, electrical definitions, Oxidation-Reduction reactions, Electrochemical series, Electrodes, Electrochemical Cells, direct Coulometry, electrolysis, electrochemical process efficiency, equilibrium Potentiometry, real Cell Voltages, Ion Selective Electrode types and designs, reference electrode designs, working electrode materials, pH buffers, Cyclic Voltammetry, Anodic Stripping Voltammetry, Polarography, differential pulse Polarography, and simple electrochemical instrumentation circuits.

  7. Preface: International Symposium on Computational Electrochemistry

    Science.gov (United States)

    Bieniasz, L. K.; Britz, D.

    2007-12-01

    Computational methods and approaches play an increasingly important role in various areas of electrochemistry, but this fact still does not find a proper reflection in the structure of electrochemical societies, nor in the calendar of international conferences or symposia. Meetings devoted to computation in electrochemistry are rare, and they are focused on specific application areas. The present symposium has been organized with the aim to bring together computationally oriented electrochemists working in diverse application areas, in order to overcome communication barriers and expose common aspects of their work. The placement of the symposium within the ICCMSE has been dictated by the intention to uncover and reinforce links between Computational Electrochemistry and Computational Science and Engineering.

  8. Graphene-based nanomaterials and their electrochemistry.

    Science.gov (United States)

    Pumera, Martin

    2010-11-01

    Graphene-based nanomaterials are in the forefront of chemical research. This tutorial review provides an introduction to their electrochemistry, its fundamentals and applications. Selected examples of applications in energy storage and sensing are presented. The synthetic methods for preparing graphenes as well as their materials chemistry are thoroughly discussed, as they have a profound influence on the electronic and electrochemical behavior of graphene-related nanomaterials. Inherent electrochemistry and spectroelectrochemistry of graphene nanomaterials is discussed thoroughly. Important application in sensing and energy storage areas are highlighted.

  9. Electrochemistry and spectro-electrochemistry of dithizonatophenylmercury(II)

    Energy Technology Data Exchange (ETDEWEB)

    Eschwege, Karel G. von; As, Lydia van [Department of Chemistry, University of the Free State, Bloemfontein 9300 (South Africa); Swarts, Jannie C., E-mail: swartsjc@ufs.ac.za [Department of Chemistry, University of the Free State, Bloemfontein 9300 (South Africa)

    2011-11-30

    Graphical abstract: Display Omitted Highlights: > CV and spectroelectrochemistry of dithizone and PhHgHDz, 3, is presented. > CV shows 3 has stable metal thioether (Hg-S-C), 1 oxidation and two reductions. > 3 is photochromic (t{sub 1/2,} {sub relaxation} = 1300 s). > Electrochemistry of ground and photo-activated 3 is identical. > Spectroelectrochemistry of 3 highlights electrochromism. - Abstract: The reactions between dithizone (H{sub 2}Dz, (1)) or potassium dithizonate (K{sup +}HDz{sup -}, (2)) and phenylmercury(II) chloride gives PhHg(HDz), (3). Complex (3) is photochromic. In dichloromethane, the blue photo-exited state of (3) exhibits a first order relaxation process to regenerate the orange ground state with rate constant 0.00053 s{sup -1}. The half life of this relaxation is ca. 1300 s. Electrochemically, on cyclic voltammetry time scale, the oxidations of (1) and (3) are different. A comparative voltammetric and spectro-electrochemical study of (1) and (3) in CH{sub 2}Cl{sub 2} containing 0.1 mol dm{sup -3} [N({sup n}Bu){sub 4}][B(C{sub 6}F{sub 5}){sub 4}] revealed that the mercapto group of (1) can be oxidised in two one-electron transfer steps. A disulphide is first produced and then in a second oxidation step, HDz{sup +} is formed. In contrast, complex (3) shows only one ligand-based oxidation step. Upon complexation with phenylmercury the free mercaptan group of (1) becomes a stable 'metal thioether', Hg-S-C, which effectively prevents disulphide formation in (3) upon electrochemical oxidation. Both (1) and (3) shows two reduction steps. The electrochemical fingerprint of blue photo-excited (3) is identical to that of the orange ground state as no new functional groups are introduced upon irradiation; only bond rotation occurs. The different electronic spectra for each of the redox states of (3), obtained from spectro-electrochemical measurements, revealed that only the (3)/(3{sup -}) couple exhibits electrochromic properties.

  10. A Unifying View of Computational Electrochemistry

    Science.gov (United States)

    Bieniasz, L. K.

    2007-11-01

    The current state of development of Computational Electrochemistry is briefly discussed, and a unifying view of the field is proposed, with the aim of stimulating a communication between, and unity of, computationally oriented electrochemists involved in diverse kinds of computations. The most recent work of the author, pertaining to the field, is also reviewed.

  11. Unconventional Electrochemistry in Micro-/Nanofluidic Systems

    Directory of Open Access Journals (Sweden)

    Sahana Sarkar

    2016-05-01

    Full Text Available Electrochemistry is ideally suited to serve as a detection mechanism in miniaturized analysis systems. A significant hurdle can, however, be the implementation of reliable micrometer-scale reference electrodes. In this tutorial review, we introduce the principal challenges and discuss the approaches that have been employed to build suitable references. We then discuss several alternative strategies aimed at eliminating the reference electrode altogether, in particular two-electrode electrochemical cells, bipolar electrodes and chronopotentiometry.

  12. Development of an Electrochemistry Teaching Sequence Using a Phenomenographic Approach

    Science.gov (United States)

    Rodriguez-Velazquez, Sorangel

    2013-01-01

    Electrochemistry is the area of chemistry that studies electron transfer reactions across an interface. Chemistry education researchers have acknowledged that difficulties in electrochemistry instruction arise due to the level of abstraction of the topic, lack of adequate explanations and representations found in textbooks, and a quantitative…

  13. Electrochemistry of oxygen ion transport in slag

    Institute of Scientific and Technical Information of China (English)

    鲁雄刚; 丁伟中; 李福燊; 李丽芬; 周国治

    2002-01-01

    A systematic experiment relating to the electrochemistry of oxygen ion transport in slag has been studied in lab.An equivalent circuit has been used to describe ion transfer between metal and slag in this paper and a kinetic model with electrochemical characteristic representing oxygen ion immigration has been worked out.The different experimental phenomena can be explained generally by this model.It can be seen that the theoretical results are in good agreement with experiments.The comparison of experimental data with model calculation proved that the electrochemical model is right.

  14. Electrochemistry of Main-Group Phthalocyanines.

    Science.gov (United States)

    1981-07-30

    to follow a linear relationship with the function r/(ze) (radius/charge). This reltionshlp may be used to facilitate the design of photocatalysts with...ze) and a function of central metal ion has been published. We have recently completed a study of the electrochemistry of main- us n i. Figure I for...SiV 54 0.074 -540 CIA 111 67.5 0.044 915 -655 1570Experimental Secfio* CiGat el 76 0.040 865 -735 1600Clintl! 94 0.032 830 -715 1545The r.-:m grUp

  15. Analytical Electrochemistry: Theory and Instrumentation of Dynamic Techniques.

    Science.gov (United States)

    Johnson, Dennis C.

    1980-01-01

    Emphasizes trends in the development of six topics concerning analytical electrochemistry, including books and reviews (34 references cited), mass transfer (59), charge transfer (25), surface effects (33), homogeneous reactions (21), and instrumentation (31). (CS)

  16. Analytical Electrochemistry: Methodology and Applications of Dynamic Techniques.

    Science.gov (United States)

    Heineman, William R.; Kissinger, Peter T.

    1980-01-01

    Reports developments involving the experimental aspects of finite and current analytical electrochemistry including electrode materials (97 cited references), hydrodynamic techniques (56), spectroelectrochemistry (62), stripping voltammetry (70), voltammetric techniques (27), polarographic techniques (59), and miscellany (12). (CS)

  17. Corrosive electrochemistry of jamesonite by cyclic voltammetry

    Institute of Scientific and Technical Information of China (English)

    余润兰; 胡岳华; 邱冠周; 覃文庆

    2004-01-01

    The corrosive electrochemistry of jamesonite was studied by cyclic voltammetry. Every peak in voltammograms was identified through thermodynamic calculation. The results show an irreversible electrode process by the strong adsorption of oxidation elemental sulfur on jamesonite. A deficient-metal and sulfur-rich compound is formed under the potential of 80 mV at pH 6.86. The passive action by elemental sulfur occurs from 80 to 470 mV and S2O23- , SO24- are produced at potential over 470 mV. The anodic peak producing SO24- is inhibited due to the deposition of PbSO4 at higher potential in Na2SO4 solution. The corrosive action of jamesonite becomes strong and the redox characterization similar to PbS, FeS and Sb2 S3 appears at pH 9.18.

  18. Preparation of silver-carbon nanotubes composites with plasma electrochemistry

    Science.gov (United States)

    Hoefft, Oliver; Lohmann, Lara; Olschewski, Mark; Endres, Frank

    2016-09-01

    Plasma electrochemistry is a powerful tool to generate free nanoparticles in aqueous solutions and especially in ionic liquids (ILs). Due to their very low vapour pressure, ionic liquids can be employed under vacuum conditions as fluid substrates or solvents. Thus, ionic liquids are well suitable electrolytes for plasma electrochemical processes delivering stable and homogeneous plasmas. We have shown that free copper and germanium nanoparticles can be obtained in ILs by applying a plasma as a mechanically contact-free electrode. Here we present our results using an argon plasma for the electrochemical synthesis of silver on pure and pre-treated multiwall carbon nanotubes (MWCNTs) in 1-ethyl-3-methylimidazolium dicyanamide. For the pre-treatment of the MWCNTS we have used a dielectric barrier discharge plasma (DBD) at atmospheric pressure. For the untreated MWCNTs we have found a formation of free silver nanoparticles between, on and in the vicinity of the carbon nanotubes. In case of the plasma treated MWCNTs a silver-carbon nanotubes composite is formed. Thus, the treatment of the MWCNTs obviously has a great influence on the deposit. Therefore we additionally have investigated the influence of the DBD on the chemical composition of the MWCNTs surface with X-Ray Photoelectron Spectroscopy.

  19. Electrochemistry of metalloproteins: protein film electrochemistry for the study of E. coli [NiFe]-hydrogenase-1.

    Science.gov (United States)

    Evans, Rhiannon M; Armstrong, Fraser A

    2014-01-01

    Protein film electrochemistry is a technique which allows the direct control of redox-active enzymes, providing particularly detailed information on their catalytic properties. The enzyme is deposited onto a working electrode tip, and through control of the applied potential the enzyme activity is monitored as electrical current, allowing for direct study of inherent activity as electrons are transferred to and from the enzyme redox center(s). No mediators are used. Because the only enzyme present in the experiment is bound at the electrode surface, gaseous and liquid phase inhibitors can be introduced and removed whilst the enzyme remains in situ. Potential control means that kinetics and thermodynamics are explored simultaneously; the kinetics of a reaction can be studied as a function of potential. Steady-state catalytic rates are observed directly as current (for a given potential) and non-steady-state rates (such as interconversions between different forms of the enzyme) are observed from the change in current with time. The more active the enzyme, the higher the current and the better the signal-to-noise. In this chapter we outline the practical aspects of PFE for studying electroactive enzymes, using the Escherichia coli [NiFe]-hydrogenase 1 (Hyd-1) as an example.

  20. JPRS Report, Science & Technology, Japan, International Society of Electrochemistry Meeting (40th) Held in Kyoto on 17-22 Sep 89

    Science.gov (United States)

    2007-11-02

    Selected "extended abstracts" presented at the 40th International Society of Electrochemistry Meeting held 17-22 Sep 89 in Kyoto, sponsored by the International Union of Pure and Applied Chemistry (IUPAC) and the Commemorative Association for the Japan World Exposition, and Organized by the Science Council of Japan and the Electrochemical Society of Japan.

  1. Tungsten Oxides for Photocatalysis, Electrochemistry, and Phototherapy.

    Science.gov (United States)

    Huang, Zhen-Feng; Song, Jiajia; Pan, Lun; Zhang, Xiangwen; Wang, Li; Zou, Ji-Jun

    2015-09-23

    The conversion, storage, and utilization of renewable energy have all become more important than ever before as a response to ever-growing energy and environment concerns. The performance of energy-related technologies strongly relies on the structure and property of the material used. The earth-abundant family of tungsten oxides (WOx ≤3 ) receives considerable attention in photocatalysis, electrochemistry, and phototherapy due to their highly tunable structures and unique physicochemical properties. Great breakthroughs have been made in enhancing the optical absorption, charge separation, redox capability, and electrical conductivity of WOx ≤3 through control of the composition, crystal structure, morphology, and construction of composite structures with other materials, which significantly promotes the efficiency of processes and devices based on this material. Herein, the properties and synthesis of WOx ≤3 family are reviewed, and then their energy-related applications are highlighted, including solar-light-driven water splitting, CO2 reduction, and pollutant removal, electrochromism, supercapacitors, lithium batteries, solar and fuel cells, non-volatile memory devices, gas sensors, and cancer therapy, from the aspect of function-oriented structure design and control.

  2. The Mesoscopic Electrochemistry of Molecular Junctions

    Science.gov (United States)

    Bueno, Paulo R.; Benites, Tiago A.; Davis, Jason J.

    2016-01-01

    Within the context of an electron dynamic (time-dependent) perspective and a voltage driving force acting to redistribute electrons between metallic and addressable molecular states, we define here the associated electron admittance and conductance. We specifically present a mesoscopic approach to resolving the electron transfer rate associated with the electrochemistry of a redox active film tethered to metallic leads and immersed in electrolyte. The methodology is centred on aligning the lifetime of the process of electron exchange with associated resistance and capacitance quantities. Notably, however, these are no longer those empirically known as charge transfer resistance and pseudo-capacitance, but are those derived instead from a consideration of the quantum states contained in molecular films and their accessibility through a scattering region existing between them and the metallic probe. The averaged lifetime (τr) associated with the redox site occupancy is specifically dependent on scattering associated with the quantum channels linking them to the underlying metallic continuum and associated with both a quantum resistance (Rq) and an electrochemical (redox) capacitance (Cr). These are related to electron transfer rate through k = 1/τr = (RqCr)‑1. The proposed mesoscopic approach is consistent with Marcus’s (electron transfer rate) theory and experimental measurements obtained by capacitance spectroscopy.

  3. Electrochemistry and electroanalytical applications of carbon nanotubes: a review.

    Science.gov (United States)

    Gong, Kuanping; Yan, Yiming; Zhang, Meining; Su, Lei; Xiong, Shaoxiang; Mao, Lanqun

    2005-12-01

    This review addresses recent developments in electrochemistry and electroanalytical chemistry of carbon nanotubes (CNTs). CNTs have been proved to possess unique electronic, chemical and structural features that make them very attractive for electrochemical studies and electrochemical applications. For example, the structural and electronic properties of the CNTs endow them with distinct electrocatalytic activities and capabilities for facilitating direct electrochemistry of proteins and enzymes from other kinds of carbon materials. These striking electrochemical properties of the CNTs pave the way to CNT-based bioelectrochemistry and to bioelectronic nanodevices, such as electrochemical sensors and biosensors. The electrochemistry and bioelectrochemistry of the CNTs are summarized and discussed, along with some common methods for CNT electrode preparation and some recent advances in the rational functionalization of the CNTs for electroanalytical applications.

  4. Shaping and exploring the micro- and nanoworld using bipolar electrochemistry.

    Science.gov (United States)

    Loget, Gabriel; Kuhn, Alexander

    2011-06-01

    Bipolar electrochemistry is a technique with a rather young history in the field of analytical chemistry. Being based on the polarization of a conducting object which is exposed to an external electric field, it allowed recently the development of new methods for controlled surface modification at the micro- and nanoscale and very original analytical applications. Using bipolar electrodes, analyte separation and detection becomes possible based on miniaturized systems. Moreover, the modified objects that can be created with bipolar electrochemistry could find applications as key components for detection systems. In this contribution, the principles of bipolar electrochemistry will be reviewed, as well as recent developments that focus on the modification of objects at the nano- and microscale and their potential application in miniaturized analytical systems.

  5. Exploiting plug-and-play electrochemistry for drug discovery.

    Science.gov (United States)

    Gao, Lixia; Teng, Yong

    2016-04-01

    Electrochemistry has emerged as a powerful analytical technique for chemical analysis of living cells, biologically active molecules and metabolites. Electrochemical biosensor, microfluidics and mass spectrometry are the most frequently used methods for electrochemical detection and monitory, which comprise a collection of extremely useful measurement tools for various fields of biology and medicine. Most recently, electrochemistry has been shown to be coupled with nanotechnology and genetic engineering to generate new enabling technologies, providing rapid, selective, and sensitive detection and diagnosis platforms. The primary focus of this review is to highlight the utility of electrochemical strategies and their conjunction with other approaches for drug metabolism and discovery. Current challenges and possible future developments and applications of electrochemistry in drug studies are also discussed.

  6. Developments in electrochemistry science inspired by Martin Fleischmann

    CERN Document Server

    Pletcher, Derek; Williams, David

    2014-01-01

    Martin Fleischmann was truly one of the 'fathers' of modern electrochemistry having made major contributions to diverse topics within electrochemical science and technology. These include the theory and practice of voltammetry and in situ spectroscopic techniques, instrumentation, electrochemical phase formation, corrosion, electrochemical engineering, electrosynthesis and cold fusion.  While intended to honour the memory of Martin Fleischmann, Developments in Electrochemistry is neither a biography nor a history of his contributions. Rather, the book is a series of critical reviews of topic

  7. Chelating ionic liquids for reversible zinc electrochemistry.

    Science.gov (United States)

    Kar, Mega; Winther-Jensen, Bjorn; Forsyth, Maria; MacFarlane, Douglas R

    2013-05-21

    Advanced, high energy-density, metal-air rechargeable batteries, such as zinc-air, are of intense international interest due to their important role in energy storage applications such as electric and hybrid vehicles, and to their ability to deal with the intermittency of renewable energy sources such as solar and wind. Ionic liquids offer a number of ideal thermal and physical properties as potential electrolytes in such large-scale energy storage applications. We describe here the synthesis and characterisation of a family of novel "chelating" ILs designed to chelate and solubilize the zinc ions to create electrolytes for this type of battery. These are based on quaternary alkoxy alkyl ammonium cations of varying oligo-ether side chains and anions such as p-toluene sulfonate, bis(trifluoromethylsulfonyl)amide and dicyanoamides. This work shows that increasing the ether chain length in the cation from two to four oxygens can increase the ionic conductivity and reduce the melting point from 67 °C to 15 °C for the tosylate system. Changing the anion also plays a significant role in the nature of the zinc deposition electrochemistry. We show that zinc can be reversibly deposited from [N(222(20201))][NTf2] and [N(222(202020201))][NTf2] beginning at -1.4 V and -1.7 V vs. SHE, respectively, but not in the case of tosylate based ILs. This indicates that the [NTf2] is a weaker coordinating anion with the zinc cation, compared to the tosylate anion, allowing the coordination of the ether chain to dominate the behavior of the deposition and stripping of zinc ions.

  8. Nanoscale Electrochemistry of sp(2) Carbon Materials: From Graphite and Graphene to Carbon Nanotubes.

    Science.gov (United States)

    Unwin, Patrick R; Güell, Aleix G; Zhang, Guohui

    2016-09-20

    Carbon materials have a long history of use as electrodes in electrochemistry, from (bio)electroanalysis to applications in energy technologies, such as batteries and fuel cells. With the advent of new forms of nanocarbon, particularly, carbon nanotubes and graphene, carbon electrode materials have taken on even greater significance for electrochemical studies, both in their own right and as components and supports in an array of functional composites. With the increasing prominence of carbon nanomaterials in electrochemistry comes a need to critically evaluate the experimental framework from which a microscopic understanding of electrochemical processes is best developed. This Account advocates the use of emerging electrochemical imaging techniques and confined electrochemical cell formats that have considerable potential to reveal major new perspectives on the intrinsic electrochemical activity of carbon materials, with unprecedented detail and spatial resolution. These techniques allow particular features on a surface to be targeted and models of structure-activity to be developed and tested on a wide range of length scales and time scales. When high resolution electrochemical imaging data are combined with information from other microscopy and spectroscopy techniques applied to the same area of an electrode surface, in a correlative-electrochemical microscopy approach, highly resolved and unambiguous pictures of electrode activity are revealed that provide new views of the electrochemical properties of carbon materials. With a focus on major sp(2) carbon materials, graphite, graphene, and single walled carbon nanotubes (SWNTs), this Account summarizes recent advances that have changed understanding of interfacial electrochemistry at carbon electrodes including: (i) Unequivocal evidence for the high activity of the basal surface of highly oriented pyrolytic graphite (HOPG), which is at least as active as noble metal electrodes (e.g., platinum) for outer

  9. Common Student Misconceptions in Electrochemistry: Galvanic, Electrolytic, and Concentration Cells.

    Science.gov (United States)

    Sanger, Michael J.; Greenbowe, Thomas J.

    1997-01-01

    Investigates student (N=16) misconceptions concerning electrochemistry related to galvanic, electrolytic, and concentration cells. Findings indicate that most students demonstrating misconceptions were still able to calculate cell potentials correctly. Discusses common misconceptions and possible sources of these. Contains 33 references.…

  10. Direct Electrochemistry With Nitrate Reductase in Chitosan Films

    Institute of Scientific and Technical Information of China (English)

    Xiao Xia CHEN; Jing Bo HU; Hong WU; Hui Bo SHAO

    2004-01-01

    Stable films made from chitosan(CS)on pyrolytic graphite electrode(PGE)gave direct electrochemistry for incorporated enzyme nitrate reductase(NR).Cyclic voltammetry of CS/NR films showed a pair of well-defined and nearly reversible redox peaks at about-0.430 V vs.SCE at pH 7.0 phosphate buffers.

  11. Unusual inherent electrochemistry of graphene oxides prepared using permanganate oxidants.

    Science.gov (United States)

    Eng, Alex Yong Sheng; Ambrosi, Adriano; Chua, Chun Kiang; Saněk, Filip; Sofer, Zdeněk; Pumera, Martin

    2013-09-16

    Graphene and graphene oxides are materials of significant interest in electrochemical devices such as supercapacitors, batteries, fuel cells, and sensors. Graphene oxides and reduced graphenes are typically prepared by oxidizing graphite in strong mineral acid mixtures with chlorate (Staudenmaier, Hofmann) or permanganate (Hummers, Tour) oxidants. Herein, we reveal that graphene oxides pose inherent electrochemistry, that is, they can be oxidized or reduced at relatively mild potentials (within the range ±1 V) that are lower than typical battery potentials. This inherent electrochemistry of graphene differs dramatically from that of the used oxidants. Graphene oxides prepared using chlorate exhibit chemically irreversible reductions, whereas graphene oxides prepared through permanganate-based methods exhibit very unusual inherent chemically reversible electrochemistry of oxygen-containing groups. Insight into the electrochemical behaviour was obtained through cyclic voltammetry, chronoamperometry, and X-ray photoelectron spectroscopy experiments. Our findings are of extreme importance for the electrochemistry community as they reveal that electrode materials undergo cyclic changes in charge/discharge cycles, which has strong implications for energy-storage and sensing devices.

  12. Au-Biocompatible metallic nanostructures in metalloprotein electrochemistry and electrocatalysis

    DEFF Research Database (Denmark)

    Jensen, Palle Skovhus; Engelbrekt, Christian; Sørensen, Karsten Holm;

    2012-01-01

    Molecular scale metallic nanoparticles coated by molecular monolayers and immobilized on single-crystal Au-electrode surfaces are efficient catalysts in metalloprotein voltammetry. Nanoparticles prepared by a new ‘‘green’’ method also exhibit strong electrocatalysis in both protein electrochemistry...

  13. (The latest developments of the physical aspects of electrochemistry)

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S.H.

    1990-09-24

    The author was one of 26 invited lecturers to discuss the latest developments of the physical aspects of electrochemistry. He interacted extensively with other lecturers and many participants from developing countries. He also visited with the Director of the Italian Synchrotron Radiation Source now under construction in Trieste, Italy.

  14. Tutorials in Nanotechnology: Focus on Physical and Analytical Electrochemistry

    Science.gov (United States)

    2010-11-29

    Society in Vienna Austria on the 5th of October 2009. This symposium was part of a continuing series of symposia at Electrochemical Society meetings that...The symposium Tutorials in Nanotechnology: Focus on Physical and Analytical Electrochemistry was held at the 216th Meeting of the Electrochemical

  15. Electrochemistry-mass spectrometry in drug metabolism and protein research

    NARCIS (Netherlands)

    Permentier, Hjalmar P.; Bruins, Andries P.; Bischoff, Rainer

    2008-01-01

    The combination of electrochemistry coupled on-line to mass spectrometry (EC-MS) forms a powerful analytical technique with unique applications in the fields of drug metabolism and proteomics. In this review the latest developments are surveyed from both instrumental and application perspectives. Th

  16. Conceptual design and experiments of electrochemistry-flushing technology for the remediation of historically Cr(Ⅵ)-contaminated soil.

    Science.gov (United States)

    Li, Dong; Sun, Delin; Hu, Siyang; Hu, Jing; Yuan, Xingzhong

    2016-02-01

    A conceptual design and experiments, electrochemistry-flushing (E-flushing), using electrochemistry to enhance flushing efficiency for the remediation of Cr(Ⅵ)-contaminated soil is presented. The rector contained three compartments vertically superposed. The upper was airtight cathode compartment containing an iron-cathode. The middle was soil layer. The bottom was anode compartment containing an iron-anode and connected to a container by circulation pumps. H2 and OH(-) ions were produced at cathode. H2 increased the gas pressure in cathode compartment and drove flushing solution into soil layer forming flushing process. OH(-) ions entered into soil layer by eletromigration and hydraulic flow to enhance the desorption of Cr(Ⅵ). High potential gradient was applied to accelerate the electromigration of desorbed Cr(Ⅵ) ions and produced joule heat to increase soil temperature to enhance Cr(Ⅵ) desorption. In anode compartment, Fe(2+) ions produced at iron-anode reduced the desorbed Cr(Ⅵ) into Cr(3+) ions, which reacted with OH(-) ions forming Cr(OH)3. Experimental results show that Cr(Ⅵ) removal efficiency of E-flushing experiments was more than double of flushing experiments and reached the maximum of removal efficiency determined by desorption kinetics. All electrochemistry processes were positively used in E-flushing technology.

  17. Direct electrochemistry of GOD on nitrogen-doped porous carbon and its biosensing

    Science.gov (United States)

    Sun, Min; Liu, Hongyu; Chen, Shouhui; Song, Yonghai; Wang, Li

    2014-11-01

    Nitrogen-doped porous carbon (N-DPC) was prepared via a simple and effective method and was characterized by X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, N2 adsorption-desorption isotherms and scanning electron microscopy. The results showed that the N-DPC with two type reticular porosities in an average diameter of 10-100 nm has a large specific surface area, which is favorable to immobilize the redox proteins for constructing biosensors. Direct electrochemistry of glucose oxidase (GOD) on the N-DPC-modified electrode was investigated. UV-vis spectroscopy showed that GOD retained its catalytic activity in the N-DPC film. Electrochemical results indicated that the modified electrode exhibited effective direct electron transfer. It demonstrated that such N-DPC could provide a good matrix for direct electrochemistry of enzymes. A novel biosensor was developed by entrapping GOD in the N-DPC-modified electrode for glucose detection and showed a stable, rapid, and reproducible electrocatalytic response, a high sensitivity, a wide linear range and a low detection limit. Moreover, the biosensor can be applied in practical analysis and exhibit good reproducibility and long-term stability.

  18. Scanning thermo-ionic microscopy for probing local electrochemistry at the nanoscale

    Science.gov (United States)

    Eshghinejad, Ahmadreza; Nasr Esfahani, Ehsan; Wang, Peiqi; Xie, Shuhong; Geary, Timothy C.; Adler, Stuart B.; Li, Jiangyu

    2016-05-01

    Conventional electrochemical characterization techniques based on voltage and current measurements only probe faradaic and capacitive rates in aggregate. In this work we develop a scanning thermo-ionic microscopy (STIM) to probe local electrochemistry at the nanoscale, based on imaging of Vegard strain induced by thermal oscillation. It is demonstrated from both theoretical analysis and experimental validation that the second harmonic response of thermally induced cantilever vibration, associated with thermal expansion, is present in all solids, whereas the fourth harmonic response, caused by local transport of mobile species, is only present in ionic materials. The origin of STIM response is further confirmed by its reduced amplitude with respect to increased contact force, due to the coupling of stress to concentration of ionic species and/or electronic defects. The technique has been applied to probe Sm-doped Ceria and LiFePO4, both of which exhibit higher concentrations of mobile species near grain boundaries. The STIM gives us a powerful method to study local electrochemistry with high sensitivity and spatial resolution for a wide range of ionic systems, as well as ability to map local thermomechanical response.

  19. Electrochemistry in Near-Critical and Supercritical Fluids. I. Ammonia.

    Science.gov (United States)

    1984-07-18

    in a supercritical fluid containing an electrolyte. We show j here that electrocheical techniques, such as cyclic voltametry and .’ chronocoulametrY...8217,_- Electrochemistry, supercritical, ammonia S&. ASSTRACT. (CGWIU&UI VOWO *fo of Rea@ d 8~ US F &I-*I 81116 Cyclic voltanmetric and chronocoulometric studies of N...Bard 4 Department of Chemi stry, The University of Texas Austin, TX 78712 (Abstract) Cyclic voittuuntric and chronocoulometric studies of NH3

  20. 2010 ELECTROCHEMISTRY GRC, JANUARY 9-15, 2010, VENTURA, CA

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Creager

    2010-12-31

    Electrochemical science plays a crucial role in many important technologies and is intimately involved in many natural phenomena. Several new Gordon Research Conferences have appeared recently that are dedicated to electrochemical technologies, however electrochemistry as a discipline continues to thrive and provide the underpinnings of these technologies. The 2010 Electrochemistry GRC will focus on a wide range of fundamental electrochemical phenomena and materials and on their application in areas involving energy storage, information storage, chemical analysis, and motion actuation. The meeting will include sessions dedicated to the following specific topics: electrochemical energy storage (e.g. batteries; at least two sessions); electrochemical motion actuation (e.g. electrokinesis); electrocatalysis; electrochemistry in digital information storage; and bioelectrochemistry (including bioanalysis). An Open Session devoted to highlighting the activities of {approx}10 young investigators and non-North American visitors via brief 10-minute talks, and two open poster sessions highlighting the contributions of approximately 60 conference participants including graduate students, will be held. Altogether the conference is expected to include approximately 90 presentations. As has been the case in the recent past, the meeting will bring together participants from academia, national labs, and the private sector, including senior and junior-level scientists, postdoctoral scientists, and graduate students for informal interactions and exchange of ideas. An affiliated Gordon-Kenan Research Seminar (GRS) will also be held with the conference. Special efforts will be made to invite participation from members of underrepresented groups.

  1. Development of an Electrochemistry Teaching Sequence using a Phenomenographic Approach

    Science.gov (United States)

    Rodriguez-Velazquez, Sorangel

    Electrochemistry is the area of chemistry that studies electron transfer reactions across an interface. Chemistry education researchers have acknowledged that difficulties in electrochemistry instruction arise due to the level of abstraction of the topic, lack of adequate explanations and representations found in textbooks, and a quantitative emphasis in the application of concepts. Studies have identified conceptions (also referred to as misconceptions, alternative conceptions, etc.) about the electrochemical process that transcends academic and preparation levels (e.g., students and instructors) as well as cultural and educational settings. Furthermore, conceptual understanding of the electrochemical process requires comprehension of concepts usually studied in physics such as electric current, resistance and potential and often neglected in introductory chemistry courses. The lack of understanding of physical concepts leads to students. conceptions with regards to the relation between the concepts of redox reactions and electric circuits. The need for instructional materials to promote conceptual understanding of the electrochemical process motivated the development of the electrochemistry teaching sequence presented in this dissertation. Teaching sequences are educational tools that aim to bridge the gap between student conceptions and the scientific acceptable conceptions that instructors expect students to learn. This teaching sequence explicitly addresses known conceptions in electrochemistry and departs from traditional instruction in electrochemistry to reinforce students. previous knowledge in thermodynamics providing the foundation for the explicit relation of redox reactions and electric circuits during electrochemistry instruction. The scientific foundations of the electrochemical process are explained based on the Gibbs free energy (G) involved rather than on the standard redox potential values (E° ox/red) of redox half-reactions. Representations of

  2. Redox-capacitor to connect electrochemistry to redox-biology.

    Science.gov (United States)

    Kim, Eunkyoung; Leverage, W Taylor; Liu, Yi; White, Ian M; Bentley, William E; Payne, Gregory F

    2014-01-07

    It is well-established that redox-reactions are integral to biology for energy harvesting (oxidative phosphorylation), immune defense (oxidative burst) and drug metabolism (phase I reactions), yet there is emerging evidence that redox may play broader roles in biology (e.g., redox signaling). A critical challenge is the need for tools that can probe biologically-relevant redox interactions simply, rapidly and without the need for a comprehensive suite of analytical methods. We propose that electrochemistry may provide such a tool. In this tutorial review, we describe recent studies with a redox-capacitor film that can serve as a bio-electrode interface that can accept, store and donate electrons from mediators commonly used in electrochemistry and also in biology. Specifically, we (i) describe the fabrication of this redox-capacitor from catechols and the polysaccharide chitosan, (ii) discuss the mechanistic basis for electron exchange, (iii) illustrate the properties of this redox-capacitor and its capabilities for promoting redox-communication between biology and electrodes, and (iv) suggest the potential for enlisting signal processing strategies to "extract" redox information. We believe these initial studies indicate broad possibilities for enlisting electrochemistry and signal processing to acquire "systems level" redox information from biology.

  3. Solvents' Critical Role in Nonaqueous Lithium-Oxygen Battery Electrochemistry.

    Science.gov (United States)

    McCloskey, B D; Bethune, D S; Shelby, R M; Girishkumar, G; Luntz, A C

    2011-05-19

    Among the many important challenges facing the development of Li-air batteries, understanding the electrolyte's role in producing the appropriate reversible electrochemistry (i.e., 2Li(+) + O2 + 2e(-) ↔ Li2O2) is critical. Quantitative differential electrochemical mass spectrometry (DEMS), coupled with isotopic labeling of oxygen gas, was used to study Li-O2 electrochemistry in various solvents, including carbonates (typical Li ion battery solvents) and dimethoxyethane (DME). In conjunction with the gas-phase DEMS analysis, electrodeposits formed during discharge on Li-O2 cell cathodes were characterized using ex situ analytical techniques, such as X-ray diffraction and Raman spectroscopy. Carbonate-based solvents were found to irreversibly decompose upon cell discharge. DME-based cells, however, produced mainly lithium peroxide on discharge. Upon cell charge, the lithium peroxide both decomposed to evolve oxygen and oxidized DME at high potentials. Our results lead to two conclusions; (1) coulometry has to be coupled with quantitative gas consumption and evolution data to properly characterize the rechargeability of Li-air batteries, and (2) chemical and electrochemical electrolyte stability in the presence of lithium peroxide and its intermediates is essential to produce a truly reversible Li-O2 electrochemistry.

  4. Advanced Electrochemistry of Individual Metal Clusters Electrodeposited Atom by Atom to Nanometer by Nanometer.

    Science.gov (United States)

    Kim, Jiyeon; Dick, Jeffrey E; Bard, Allen J

    2016-11-15

    Metal clusters are very important as building blocks for nanoparticles (NPs) for electrocatalysis and electroanalysis in both fundamental and applied electrochemistry. Attention has been given to understanding of traditional nucleation and growth of metal clusters and to their catalytic activities for various electrochemical applications in energy harvesting as well as analytical sensing. Importantly, understanding the properties of these clusters, primarily the relationship between catalysis and morphology, is required to optimize catalytic function. This has been difficult due to the heterogeneities in the size, shape, and surface properties. Thus, methods that address these issues are necessary to begin understanding the reactivity of individual catalytic centers as opposed to ensemble measurements, where the effect of size and morphology on the catalysis is averaged out in the measurement. This Account introduces our advanced electrochemical approaches to focus on each isolated metal cluster, where we electrochemically fabricated clusters or NPs atom by atom to nanometer by nanometer and explored their electrochemistry for their kinetic and catalytic behavior. Such approaches expand the dimensions of analysis, to include the electrochemistry of (1) a discrete atomic cluster, (2) solely a single NP, or (3) individual NPs in the ensemble sample. Specifically, we studied the electrocatalysis of atomic metal clusters as a nascent electrocatalyst via direct electrodeposition on carbon ultramicroelectrode (C UME) in a femtomolar metal ion precursor. In addition, we developed tunneling ultramicroelectrodes (TUMEs) to study electron transfer (ET) kinetics of a redox probe at a single metal NP electrodeposited on this TUME. Owing to the small dimension of a NP as an active area of a TUME, extremely high mass transfer conditions yielded a remarkably high standard ET rate constant, k(0), of 36 cm/s for outer-sphere ET reaction. Most recently, we advanced nanoscale

  5. Electrochemistry and green chemical processes: electrochemical ozone production

    Directory of Open Access Journals (Sweden)

    Leonardo M. da Silva

    2003-12-01

    Full Text Available After an introductory discussion emphasising the importance of electrochemistry for the so-called Green Chemical Processes, the article presents a short discussion of the classical ozone generation technologies. Next a revision of the electrochemical ozone production technology focusing on such aspects as: fundamentals, latest advances, advantages and limitations of this technology is presented. Recent results about fundamentals of electrochemical ozone production obtained in our laboratory, using different electrode materials (e.g. boron doped diamond electrodes, lead dioxide and DSAÒ-based electrodes also are presented. Different chemical processes of interest to the solution of environmental problems involving ozone are discussed.

  6. Electrospray ion source with reduced analyte electrochemistry

    Science.gov (United States)

    Kertesz, Vilmos; Van Berkel, Gary J

    2013-07-30

    An electrospray ion (ESI) source and method capable of ionizing an analyte molecule without oxidizing or reducing the analyte of interest. The ESI source can include an emitter having a liquid conduit, a working electrode having a liquid contacting surface, a spray tip, a secondary working electrode, and a charge storage coating covering partially or fully the liquid contacting surface of the working electrode. The liquid conduit, the working electrode and the secondary working electrode can be in liquid communication. The electrospray ion source can also include a counter electrode proximate to, but separated from, said spray tip. The electrospray ion source can also include a power system for applying a voltage difference between the working electrodes and a counter-electrode. The power system can deliver pulsed voltage changes to the working electrodes during operation of said electrospray ion source to minimize the surface potential of the charge storage coating.

  7. A Review on Direct Electrochemistry of Catalase for Electrochemical Sensors

    Directory of Open Access Journals (Sweden)

    Periasamy Arun Prakash

    2009-03-01

    Full Text Available Catalase (CAT is a heme enzyme with a Fe(III/II prosthetic group at its redox centre. CAT is present in almost all aerobic living organisms, where it catalyzes the disproportionation of H2O2 into oxygen and water without forming free radicals. In order to study this catalytic mechanism in detail, the direct electrochemistry of CAT has been investigated at various modified electrode surfaces with and without nanomaterials. The results show that CAT immobilized on nanomaterial modified electrodes shows excellent catalytic activity, high sensitivity and the lowest detection limit for H2O2 determination. In the presence of nanomaterials, the direct electron transfer between the heme group of the enzyme and the electrode surface improved significantly. Moreover, the immobilized CAT is highly biocompatible and remains extremely stable within the nanomaterial matrices. This review discusses about the versatile approaches carried out in CAT immobilization for direct electrochemistry and electrochemical sensor development aimed as efficient H2O2 determination. The benefits of immobilizing CAT in nanomaterial matrices have also been highlighted.

  8. Bipolar electrochemistry: from materials science to motion and beyond.

    Science.gov (United States)

    Loget, Gabriel; Zigah, Dodzi; Bouffier, Laurent; Sojic, Neso; Kuhn, Alexander

    2013-11-19

    Bipolar electrochemistry, a phenomenon which generates an asymmetric reactivity on the surface of conductive objects in a wireless manner, is an important concept for many purposes, from analysis to materials science as well as for the generation of motion. Chemists have known the basic concept for a long time, but it has recently attracted additional attention, especially in the context of micro- and nanoscience. In this Account, we introduce the fundamentals of bipolar electrochemistry and illustrate its recent applications, with a particular focus on the fields of materials science and dynamic systems. Janus particles, named after the Roman god depicted with two faces, are currently in the heart of many original investigations. These objects exhibit different physicochemical properties on two opposite sides. This makes them a unique class of materials, showing interesting features. They have received increasing attention from the materials science community, since they can be used for a large variety of applications, ranging from sensing to photosplitting of water. So far the great majority of methods developed for the generation of Janus particles breaks the symmetry by using interfaces or surfaces. The consequence is often a low time-space yield, which limits their large scale production. In this context, chemists have successfully used bipolar electrodeposition to break the symmetry. This provides a single-step technique for the bulk production of Janus particles with a high control over the deposit structure and morphology, as well as a significantly improved yield. In this context, researchers have used the bipolar electrodeposition of molecular layers, metals, semiconductors, and insulators at one or both reactive poles of bipolar electrodes to generate a wide range of Janus particles with different size, composition and shape. In using bipolar electrochemistry as a driving force for generating motion, its intrinsic asymmetric reactivity is again the

  9. Electrochemical oxidation of quaternary ammonium electrolytes : Unexpected side reactions in organic electrochemistry

    NARCIS (Netherlands)

    Nouri Nigjeh, Eslam; de Vries, Marcel; Bruins, Andries P.; Bischoff, Rainer; Permentier, Hjalmar P.

    2012-01-01

    Quaternary ammonium salts are among the most widely used electrolytes in organic electrochemistry, but there is little known about their unwanted side oxidation reactions. We have, therefore, studied the constant potential oxidation products of quaternary ammonium electrolytes using mass spectrometr

  10. Electrochemistry-mass spectrometry for mechanistic studies and simulation of oxidation processes in the environment.

    Science.gov (United States)

    Hoffmann, Th; Hofmann, D; Klumpp, E; Küppers, S

    2011-02-01

    Electrochemistry (EC) coupled to mass spectrometry (MS) has already been successfully applied to metabolism research for pharmaceutical applications, especially for the oxidation behaviour of drug substances. Xenobiotics (chemicals in the environment) also undergo various conversions; some of which are oxidative reactions. Therefore, EC-MS might be a suitable tool for the investigation of oxidative behaviour of xenobiotics. A further evaluation of this approach to environmental research is presented in the present paper using sulfonamide antibiotics. The results with sulfadiazine showed that EC-MS is a powerful tool for the elucidation of the oxidative degradation mechanism within a short time period. In addition, it was demonstrated that EC-MS can be used as a fast and easy method to model the chemical binding of xenobiotics to soil. The reaction of sulfadiazine with catechol, as a model substance for organic matter in soil, led to the expected chemical structure. Finally, by using EC-MS a first indication was obtained of the persistence of a component under chemical oxidation conditions for the comparison of the oxidative stability of different classes of xenobiotics. Overall, using just a few examples, the study demonstrates that EC-MS can be applied as a versatile tool for mechanistic studies of oxidative degradation pathways of xenobiotics and their possible interaction with soil organic matter as well as their oxidative stability in the environment. Further studies are needed to evaluate the full range of possibilities of the application of EC-MS in environmental research.

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

    CERN Document Server

    Santos, Elizabeth

    2011-01-01

    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

  12. Solid-state electrochemistry on the nanometer and atomic scales: the scanning probe microscopy approach

    Science.gov (United States)

    Strelcov, Evgheni; Yang, Sang Mo; Jesse, Stephen; Balke, Nina; Vasudevan, Rama K.; Kalinin, Sergei V.

    2016-07-01

    Energy technologies of the 21st century require an understanding and precise control over ion transport and electrochemistry at all length scales - from single atoms to macroscopic devices. This short review provides a summary of recent studies dedicated to methods of advanced scanning probe microscopy for probing electrochemical transformations in solids at the meso-, nano- and atomic scales. The discussion presents the advantages and limitations of several techniques and a wealth of examples highlighting peculiarities of nanoscale electrochemistry.

  13. Single Pt nanowire electrode: preparation, electrochemistry, and electrocatalysis.

    Science.gov (United States)

    Li, Yongxin; Wu, Qingqing; Jiao, Shoufeng; Xu, Chaodi; Wang, Lun

    2013-04-16

    A single Pt nanowire electrode (SPNE) was fabricated through HF etching process from Pt disk nanoelectrode and an underpotential deposition (UPD) redox replacement technique. The electrochemical experiments showed that SPNE had steady-state electrochemical responses at redox species solution and the mass transfer rates were affected by the lengths and radii of SPNEs. The prepared SPNEs were utilized to examine the oxygen-reduction reaction in a KOH solution to explore the feasibility of electrocatalytic activity of single Pt nanowire and the results showed that the electrocatalytic activity of SPNE was dependent on the surface position of single Pt nanowire: the tip end position is more active than the sidewall position. Meanwhile, the electrocatalytic activity of SPNE was related to the radius of nanowire. These observations are not only important to understand the structure-function relationship in single nanowire level but have significant implications for the synthesis and selection of novel catalysts with high efficiency used in electrochemistry, energy, bioanalysis, etc.

  14. Selenium electrochemistry. Applications in the nuclear fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    Maslennikov, A.; Peretroukhine, V. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry; David, F. [Centre National de la Recherche Scientifique (CNRS), 91 - Orsay (France); Lecomte, M. [CEA Centre d' Etudes de la Valle du Rhone, 30 - Marcoule (France). Direction du Cycle du Combustible

    1999-07-01

    Modern state of selenium electrochemistry is reviewed in respect of the application of electrochemical methods for the study of the behavior of this element and its quantitative analysis in the solutions of nuclear fuel cycle. The review includes the data on the redox potentials of Se in aqueous solutions, and the data on Se redox reactions, occurring at mercury and solid electrodes. Analysis of the available literature data shows that the inverse stripping voltammetry technique for trace Se concentration and determination seems to be the most promising in application for the Se determination in PUREX solutions and in radioactive wastes. The adaptation of the ISV technique for the trace Se concentration and determination in the solutions of the nuclear fuel cycle is indicated as the most prospective goal of the future experimental study. (author)

  15. Electrochemistry-mass spectrometry in drug metabolism and protein research.

    Science.gov (United States)

    Permentier, Hjalmar P; Bruins, Andries P; Bischoff, Rainer

    2008-01-01

    The combination of electrochemistry coupled on-line to mass spectrometry (EC-MS) forms a powerful analytical technique with unique applications in the fields of drug metabolism and proteomics. In this review the latest developments are surveyed from both instrumental and application perspectives. The limitations and solutions for coupling an electrochemical system to a mass spectrometer are discussed. The electrochemical mimicking of drug metabolism, specifically by Cytochrome P450, is high-lighted as an application with high biomedical relevance. The EC-MS analysis of proteins also has promising new applications for both proteomics research and biomarker discovery. EC-MS has furthermore advantages for improved analyte detection with mass spectrometry, both for small molecules and large biomolecules. Finally, potential future directions of development of the technique are briefly discussed.

  16. Electrochemistry of xanthine oxidase and its interaction with nitric oxide.

    Science.gov (United States)

    Zhou, Hui; Xu, Yi; Chen, Ting; Suzuki, Iwao; Li, Genxi

    2006-02-01

    With the help of nanocrystalline TiO2, the direct electrochemistry of xanthine oxidase (XOD) was achieved and two pairs of redox waves were observed. The interaction between XOD and nitric oxide (NO) was also investigated. The experimental results reveal that NO can be reduced at a XOD-nano TiO2 film modified electrode. When the NO concentration was low, the reduced product, HNO, would inactivate the protein. However, when the NO concentration was high, HNO would continue to react with NO to form N2O2- and N3O3-, which would not inhibit XOD, and thus the amount of active protein did not decrease any further.

  17. Predominating stable adsorption and direct electrochemistry of glucose oxidase on carbon nanotubes by oxygen-containing groups

    Institute of Scientific and Technical Information of China (English)

    Chun Hai Yang; Cheng Guo Hu; Sheng Shui Hu

    2007-01-01

    Stable adsorption and direct electrochemistry of glucose oxidase (GOx) occurred on nitric acid (HNO3)-treated multi-walled carbon nanotubes (MWNTs) instead of as-received MWNTs, demonstrating the critical roles of oxygen-containing groups in stable adsorption and direct electrochemistry of GOx on carbon nanotubes (CNTs).

  18. Direct Electrochemistry of Horseradish Peroxidase-Gold Nanoparticles Conjugate

    Directory of Open Access Journals (Sweden)

    Chanchal K. Mitra

    2009-02-01

    Full Text Available We have studied the direct electrochemistry of horseradish peroxidase (HRP coupled to gold nanoparticles (AuNP using electrochemical techniques, which provide some insight in the application of biosensors as tools for diagnostics because HRP is widely used in clinical diagnostics kits. AuNP capped with (i glutathione and (ii lipoic acid was covalently linked to HRP. The immobilized HRP/AuNP conjugate showed characteristic redox peaks at a gold electrode. It displayed good electrocatalytic response to the reduction of H2O2, with good sensitivity and without any electron mediator. The covalent linking of HRP and AuNP did not affect the activity of the enzyme significantly. The response of the electrode towards the different concentrations of H2O2 showed the characteristics of Michaelis Menten enzyme kinetics with an optimum pH between 7.0 to 8.0. The preparation of the sensor involves single layer of enzyme, which can be carried out efficiently and is also highly reproducible when compared to other systems involving the layer-by-layer assembly, adsorption or encapsulation of the enzyme. The immobilized AuNP-HRP can be used for immunosensor applications

  19. LIGA-based microsystem manufacturing:the electrochemistry of through-mold depostion and material properties.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, James J. (Sandia National Laboratories, Livermore, CA); Goods, Steven Howard (Sandia National Laboratories, Livermore, CA)

    2005-06-01

    The report presented below is to appear in ''Electrochemistry at the Nanoscale'', Patrik Schmuki, Ed. Springer-Verlag, (ca. 2005). The history of the LIGA process, used for fabricating dimensional precise structures for microsystem applications, is briefly reviewed, as are the basic elements of the technology. The principal focus however, is on the unique aspects of the electrochemistry of LIGA through-mask metal deposition and the generation of the fine and uniform microstructures necessary to ensure proper functionality of LIGA components. We draw from both previously published work by external researchers in the field as well as from published and unpublished studies from within Sandia.

  20. Synthesis, Characterization, and Electrochemistry of sigma-Bonded Cobalt Corroles in High Oxidation States.

    Science.gov (United States)

    Will, Stefan; Lex, Johann; Vogel, Emanuel; Adamian, Victor A.; Van Caemelbecke, Eric; Kadish, Karl M.

    1996-09-11

    The synthesis, electrochemistry, spectroscopy, and structural characterization of two high-valent phenyl sigma-bonded cobalt corroles containing a central cobalt ion in formal +IV and +V oxidation states is presented. The characterized compounds are represented as phenyl sigma-bonded cobalt corroles, (OEC)Co(C(6)H(5)) and [(OEC)Co(C(6)H(5))]ClO(4), where OEC is the trianion of 2,3,7,8,12,13,17,18-octaethylcorrole. The electronic distribution in both molecules is discussed in terms of their NMR and EPR spectroscopic data, magnetic susceptibility, and electrochemistry.

  1. Direct Electrochemistry and Electrocatalysis of Myoglobin Immobilized on Graphene-CTAB-Ionic Liquid Nanocomposite Film

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Honggang; Wu, Hong; Wang, Jun; Liu, Jun; Jiang, Yanxia; Sun, Shigang; Lin, Yuehe

    2010-10-01

    We have investigated direct electrochemistry and electrocatalysis of myoglobin immobilized on graphene-cetylramethylammonium bromide (CTAB)-ionic liquid nanocomposite film on a glassy carbon electrode. The nanocomposite was characterized by TEM, SEM, XPS, and electrochemistry. It was found that the high surface area of graphene was helpful for immobilizing more proteins and the nanocomposite film can provide a favorable microenvironment for MB to retain its native structure and activity and to achieve reversible direct electron transfer reaction at an electrode. The nanocomposite films also exhibit good stability and catalytic activities for the electrocatalytic reduction of H2O2.

  2. Martian Dust Devil Electron Avalanche Process and Associated Electrochemistry

    Science.gov (United States)

    Jackson, Telana L.; Farrell, William M.; Delory, Gregory T.; Nithianandam, Jeyasingh

    2010-01-01

    Mars' dynamic atmosphere displays localized dust devils and larger, global dust storms. Based on terrestrial analog studies, electrostatic modeling, and laboratory work these features will contain large electrostatic fields formed via triboelectric processes. In the low-pressure Martian atmosphere, these fields may create an electron avalanche and collisional plasma due to an increase in electron density driven by the internal electrical forces. To test the hypothesis that an electron avalanche is sustained under these conditions, a self-consistent atmospheric process model is created including electron impact ionization sources and electron losses via dust absorption, electron dissociation attachment, and electron/ion recombination. This new model is called the Dust Devil Electron Avalanche Model (DDEAM). This model solves simultaneously nine continuity equations describing the evolution of the primary gaseous chemical species involved in the electrochemistry. DDEAM monitors the evolution of the electrons and primary gas constituents, including electron/water interactions. We especially focus on electron dynamics and follow the electrons as they evolve in the E field driven collisional gas. When sources and losses are self-consistently included in the electron continuity equation, the electron density grows exponentially with increasing electric field, reaching an equilibrium that forms a sustained time-stable collisional plasma. However, the character of this plasma differs depending upon the assumed growth rate saturation process (chemical saturation versus space charge). DDEAM also shows the possibility of the loss of atmospheric methane as a function of electric field due to electron dissociative attachment of the hydrocarbon. The methane destruction rates are presented and can be included in other larger atmospheric models.

  3. Towards combined electrochemistry and surface-enhanced resonance Raman of heme proteins: Improvement of diffusion electrochemistry of cytochrome c at silver electrodes chemically modified with 4-mercaptopyridine.

    Science.gov (United States)

    Millo, Diego; Ranieri, Antonio; Koot, Wynanda; Gooijer, Cees; van der Zwan, Gert

    2006-08-01

    To date, a successful combination of surface-enhanced resonance Raman spectroscopy (SERRS) and electrochemistry to study heme proteins is inhibited by the problems raised by the prerequisite to use silver as electrode metal. This paper indicates an approach to overcome these problems. It describes a quick and reproducible procedure to prepare silver electrodes chemically modified with 4-mercaptopyridine suitable to perform diffusion electrochemistry of cytochrome c (cyt c). The method involves the employment of a mechanical and a chemical treatment and avoids the use of alumina slurries and any electrochemical pretreatment. Cyclic voltammetry (CV) was used to test the electrochemical response of cyt c, and the CV signals were found identical with those obtained on gold electrodes under the same experimental conditions. Compared to previous literature, a significant improvement of the CV signal of cyt c at silver electrodes was achieved. Preliminary results show that this treatment can be also successfully employed for the preparation of SERRS-active electrodes.

  4. Electrochemically modulated liquid chromatography: Theoretical investigations and applications from the perspectives of chromatography and interfacial electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Keller, David W.

    2005-05-01

    Electrochemically modulated liquid chromatography (EMLC) employs a conductive material as both a stationary phase for chromatographic separations and as a working electrode for performing electrochemistry experiments. This dual functionality gives EMLC the capacity to manipulate chromatographic separations by changing the potential applied (E{sub app}) to the stationary phase with respect to an external reference. The ability to monitor retention as a function of E{sub app} provides a means to chromatographically monitor electrosorption processes at solid-liquid interfaces. In this dissertation, the retention mechanism for EMLC is examined from the perspective of electrical double layer theory and interfacial thermodynamics. From the chromatographic data, it is possible to determine the interfacial excess ({Lambda}) of a solute and changes in interfacial tension (d{gamma}) as a function of both E{sub app} and the supporting electrolyte concentration. Taken together, these two experimentally manipulated parameters can be examined within the context of the Gibbs adsorption equation to delineate the contribution of a variety of interfacial properties, including the charge of solute on the stationary phase and the potential of zero charge (PZC), to the mechanism behind EMLC-based retention. The chromatographic probing of interfacial phenomena is complemented by electroanalytical experiments that exploit the ability to monitor the electronic current flowing through an EMLC column. Cyclic voltammetry and chronoamperometry of an EMLC column are used to determine the electronic performance characteristics of an EMLC column. An electrochemical flow injection analysis of a column is provided in which the current required to maintain a constant E{sub app} is monitored and provides a way to examine the influence that acetonitrile and supporting electrolyte composition, flow rate, column backpressure, and ionic strength have on the structure of electrified interfaces.

  5. Electrochemically modulated liquid chromatography: Theoretical investigations and applications from the perspectives of chromatography and interfacial electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Keller, David W. [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    Electrochemically modulated liquid chromatography (EMLC) employs a conductive material as both a stationary phase for chromatographic separations and as a working electrode for performing electrochemistry experiments. This dual functionality gives EMLC the capacity to manipulate chromatographic separations by changing the potential applied (Eapp) to the stationary phase with respect to an external reference. The ability to monitor retention as a function of Eapp provides a means to chromatographically monitor electrosorption processes at solid-liquid interfaces. In this dissertation, the retention mechanism for EMLC is examined from the perspective of electrical double layer theory and interfacial thermodynamics. From the chromatographic data, it is possible to determine the interfacial excess (Λ) of a solute and changes in interfacial tension (dγ) as a function of both Eapp and the supporting electrolyte concentration. Taken together, these two experimentally manipulated parameters can be examined within the context of the Gibbs adsorption equation to delineate the contribution of a variety of interfacial properties, including the charge of solute on the stationary phase and the potential of zero charge (PZC), to the mechanism behind EMLC-based retention. The chromatographic probing of interfacial phenomena is complemented by electroanalytical experiments that exploit the ability to monitor the electronic current flowing through an EMLC column. Cyclic voltammetry and chronoamperometry of an EMLC column are used to determine the electronic performance characteristics of an EMLC column. An electrochemical flow injection analysis of a column is provided in which the current required to maintain a constant Eapp is monitored and provides a way to examine the influence that acetonitrile and supporting electrolyte composition, flow rate, column backpressure, and ionic strength have on the structure of electrified interfaces.

  6. Serendipity: Genesis of the Electrochemical Instrumentation at Princeton Applied Research Corporation

    Science.gov (United States)

    Flato, J. B.

    2007-01-01

    Princeton Applied Research Corporation (PAR) was a small electronic instrument company in early 1960s but once they entered electrochemistry they were very successful. Since then they have developed and designed successful instruments with their tremendous knowledge and have made great contribution to the field of analytical chemistry.

  7. Conceptual Difficulties Experienced by Senior High School Students of Electrochemistry: Electrochemical (Galvanic) and Electrolytic Cells.

    Science.gov (United States)

    Garnett, Pamela J.; Treagust, David F.

    1992-01-01

    This research used semistructured interviews to investigate students' (n=32) understanding of electrochemistry following a 7-9 week course of instruction. Three misconceptions were identified and incorporated with five previously reported into an alternative framework about electric current involving drifting electrons. Also noted was the tendency…

  8. In vitro mimicry of metabolic oxidation reactions by electrochemistry/mass spectrometry

    NARCIS (Netherlands)

    Jurva, U; Wikstrom, HV; Bruins, AP

    2000-01-01

    The aim of these studies was to investigate the scope and limitations of electrochemistry on-line with mass spectrometry as a quick and convenient way to mimic phase I:oxidative reactions in drug metabolism. A compound with previously reported in vitro and in vivo metabolism, the dopamine agonist 2-

  9. Semiconductor electrochemistry of coal pyrite. Final technical report, September 1990--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Osseo-Asare, K.; Wei, D.

    1996-01-01

    This project is concerned with the physiochemical processes occuring at the pyrite/aqueous interface, in the context of coal cleaning, desulfurization, and acid mine drainage. The use of synthetic particles of pyrite as model electrodes to investigate the semiconductor electrochemistry of pyrite is employed.

  10. Electrochemistry of Single Metalloprotein and DNA‐Based Molecules at Au(111) Electrode Surfaces

    DEFF Research Database (Denmark)

    Salvatore, Princia; Zeng, Dongdong; Karlsen, Kasper Kannegård;

    2013-01-01

    We have briefly overviewed recent efforts in the electrochemistry of single transition metal complex, redox metalloprotein, and redox‐marked oligonucleotide (ON) molecules. We have particularly studied self‐assembled molecular monolayers (SAMs) of several 5′‐C6‐SH single‐ (ss) and double‐strand (ds...

  11. 电化学学术会议年历%Electrochemistry Calendar

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    International Symposium in Buenos Aires: Challenges on Rechargeable Lithium Oxygen Batteries Date: 17-19 September, 2012 Location: Buenos Aires, Argentina Sponsored by : Consejo Nacional de Investigaciones Cientificas y T6cnicas & International Society of Electro-chemistry (ISE)

  12. Sulfur ligand mediated electrochemistry of gold surfaces and nanoparticles: what, how, and why

    DEFF Research Database (Denmark)

    Chi, Qijin; Ford, Michael J.; Halder, Arnab;

    2017-01-01

    Gold surfaces are widely used in electrochemistry whilst gold nanoparticles have very many uses, with both the surfaces and the particles often being protected by sulfur-bound organic ligands. The ligands not only provide chemical stability but also directly participate in many desired processes....

  13. Electrochemistry and Electrocatalysis with Hemoglobin in DHP- PDDA Surfactant-Polymer Multibilayer Composite Films

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Polyionic complex DHP-PDDA was prepared by reacting anionic surfactant dihexadecyl phosphate (DHP) with polycationic poly(diallyldimethyl ammonium) (PDDA). Thin films made from DHP-PDDA with incorporated hemoglobin (Hb) on pyrolytic graphite (PG) electrodes were characterized by electrochemistry and other techniques.

  14. The Effects of Problem-Based Learning (PBL) on the Academic Achievement of Students Studying "Electrochemistry"

    Science.gov (United States)

    Günter, Tugçe; Alpat, Sibel Kilinç

    2017-01-01

    This study investigates the effects of problem-based learning (PBL) on students' academic achievements in studying "Electrochemistry" within a course on Analytical Chemistry. The research was of a pretest-posttest control group quasi-experimental design and it was conducted with second year students in the Chemistry Teaching Program at…

  15. Investigating Nanoscale Electrochemistry with Surface- and Tip-Enhanced Raman Spectroscopy.

    Science.gov (United States)

    Zaleski, Stephanie; Wilson, Andrew J; Mattei, Michael; Chen, Xu; Goubert, Guillaume; Cardinal, M Fernanda; Willets, Katherine A; Van Duyne, Richard P

    2016-09-20

    The chemical sensitivity of surface-enhanced Raman spectroscopy (SERS) methodologies allows for the investigation of heterogeneous chemical reactions with high sensitivity. Specifically, SERS methodologies are well-suited to study electron transfer (ET) reactions, which lie at the heart of numerous fundamental processes: electrocatalysis, solar energy conversion, energy storage in batteries, and biological events such as photosynthesis. Heterogeneous ET reactions are commonly monitored by electrochemical methods such as cyclic voltammetry, observing billions of electrochemical events per second. Since the first proof of detecting single molecules by redox cycling, there has been growing interest in examining electrochemistry at the nanoscale and single-molecule levels. Doing so unravels details that would otherwise be obscured by an ensemble experiment. The use of optical spectroscopies, such as SERS, to elucidate nanoscale electrochemical behavior is an attractive alternative to traditional approaches such as scanning electrochemical microscopy (SECM). While techniques such as single-molecule fluorescence or electrogenerated chemiluminescence have been used to optically monitor electrochemical events, SERS methodologies, in particular, have shown great promise for exploring electrochemistry at the nanoscale. SERS is ideally suited to study nanoscale electrochemistry because the Raman-enhancing metallic, nanoscale substrate duly serves as the working electrode material. Moreover, SERS has the ability to directly probe single molecules without redox cycling and can achieve nanoscale spatial resolution in combination with super-resolution or scanning probe microscopies. This Account summarizes the latest progress from the Van Duyne and Willets groups toward understanding nanoelectrochemistry using Raman spectroscopic methodologies. The first half of this Account highlights three techniques that have been recently used to probe few- or single-molecule electrochemical

  16. Role of Palladium in the Redox Electrochemistry of Ferrocene Monocarboxylic Acid Encapsulated Within ORMOSIL Networks

    Directory of Open Access Journals (Sweden)

    B. Upadhyay

    2005-07-01

    Full Text Available We report herein the effect of palladium on the redox electrochemistry of ferrocene monocarboxylic acid encapsulated within an organically modified sol-gel glass network (ORMOSIL. It has been found that amount of palladium and its geometrical distribution significantly alter the redox electrochemistry of FcMCA. The geometrical distribution of palladium has been controlled by two methods: (i palladium is allowed to link within nanostructured network of the ORMOSIL which was subsequently availed from the reactivity of palladium chloride and trimethoxysilane; (ii palladium powder is encapsulated together FcMCA thus allowing the presence of palladium within the nanoporous domain. The content of palladium is varied by controlling the reaction dynamics of palladium chloride and trimethoxysilane interaction. For this we initially allowed to trigger hydrolysis, condensation and poly-condensation of trimethoxysilane and dimethyldiethoxysilane in acidic medium and subsequently partially dried ORMOSIL film was allowed to interact with palladium chloride. Even with partially dried ORMOSIL derived from trimethoxysilane and dimethyldiethoxysilane undergoes rapid interaction with palladium chloride and the transparent color of ORMOSIL changed to a black colour due to the formation of palladium silicon linkage. The palladium-silicon linkage has been identified by NMR, UV-VIS and transmission electron spectroscopy. The electrochemistry of FcMCA encapsulated within such an ORMOSIL matrix has been studied. Excellent redox electrochemistry of ferrocene monocarboxylic acid having peak potential separation tending to 0 for a multilayered electrode was investigated. The palladium content has been found to affect the redox electrochemistry of ferrocene as well as electrocatalytic efficiency of new ORMOSIL material. The electroanalysis of NADH is reported. The modified electrode is very sensitive to NADH with lowest detection limit of < 1 μM.

  17. SOME RECENT STUDIES IN RUGHENIUM ELECTROCHEMISTRY AND ELECTROCATALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    MARINKOVIC, N.S.; VUKMIROVIC, M.B.; ADZIC, R.R.

    2006-08-01

    Ruthenium is a metal of a considerable importance in electrochemical science and technology. It is a catalyst or co-catalyst material in Pt-Ru alloys for methanol- and reformate hydrogen-oxidation in fuel cells, while ruthenium oxide, a component in chlorine-evolution catalysts, represents an attractive material for electrochemical supercapacitors. Its facile surface oxidation generates an oxygen-containing species that provides active oxygen in some reactions. Ru sites in Pt-Ru catalysts increase the ''CO tolerance'' of Pt in the catalytic oxidation-reaction in direct methanol fuel cells (DMFC) and in reformate hydrogen-oxidation in proton exchange membrane fuel cells (PEMFC). The mechanism of Ru action is not completely understood, although current consensus revolves around the so-called ''bifunctional mechanism'' wherein Ru provides oxygenated species to oxidize CO that blocks Pt sites, and has an electronic effect on Pt-CO interaction. While various studies of polycrystalline Ru go back several decades those involving single crystal surfaces and the structural sensitivity of reactions on Ru surfaces emerged only recently. Using well-ordered single crystalline surfaces brings useful information as the processes on realistic catalysts are far too complex to allow identification of the microscopic reaction steps. In this article, we focus on progress in model systems and conditions, such as electrochemistry and electrocatalysis on bare and Pt-modified well-ordered Ru(0001) and Ru(10{bar 1}0) single-crystal surfaces. We also review current understanding of the mechanistic principles of Pt-Ru systems and a new development of a Pt submonolayer on Ru support electrocatalyst. Ruthenium crystallizes in a hexagonal close-packed structure, (hcp). Figure 1.1 shows the two single crystal surfaces of Ru. The Ru(0001) surface possesses the densest, i.e. hexagonal arrangement of atoms, Fig. 1.1a. The other plane, Ru(10{bar 1}0), can have

  18. Microbial Electrochemistry and its Application to Energy and Environmental Issues

    Science.gov (United States)

    Hastings, Jason Thomas

    Microbial electrochemistry forms the basis of a wide range of topics from microbial fuel cells to fermentation of carbon food sources. The ability to harness microbial electron transfer processes can lead to a greener and cleaner future. This study focuses on microbial electron transfer for liquid fuel production, novel electrode materials, subsurface environments and removal of unwanted byproducts. In the first chapter, exocellular electron transfer through direct contact utilizing passive electrodes for the enhancement of bio-fuel production was tested. Through the application of microbial growth in a 2-cell apparatus on an electrode surface ethanol production was enhanced by 22.7% over traditional fermentation. Ethanol production efficiencies of close to 95% were achieved in a fraction of the time required by traditional fermentation. Also, in this chapter, the effect of exogenous electron shuttles, electrode material selection and resistance was investigated. Power generation was observed using the 2-cell passive electrode system. An encapsulation method, which would also utilize exocellular transfer of electrons through direct contact, was hypothesized for the suspension of viable cells in a conductive polymer substrate. This conductive polymer substrate could have applications in bio-fuel production. Carbon black was added to a polymer solution to test electrospun polymer conductivity and cell viability. Polymer morphology and cell viability were imaged using electron and optical microscopy. Through proper encapsulation, higher fuel production efficiencies would be achievable. Electron transfer through endogenous exocellular protein shuttles was observed in this study. Secretion of a soluble redox active exocellular protein by Clostridium sp. have been shown utilizing a 2-cell apparatus. Cyclic voltammetry and gel electrophoresis were used to show the presence of the protein. The exocellular protein is capable of reducing ferrous iron in a membrane separated

  19. Proceedings of the conference on electrochemistry of carbon allotropes: Graphite, fullerenes and diamond

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, K. [ed.] [Lawrence Berkeley National Lab., CA (United States); Scherson, D. [ed.] [Case Western Reserve Univ., Cleveland, OH (United States)

    1998-02-01

    This conference provided an opportunity for electrochemists, physicists, materials scientists and engineers to meet and exchange information on different carbon allotropes. The presentations and discussion among the participants provided a forum to develop recommendations on research and development which are relevant to the electrochemistry of carbon allotropes. The following topics which are relevant to the electrochemistry of carbon allotropes were addressed: Graphitized and disordered carbons, as Li-ion intercalation anodes for high-energy-density, high-power-density Li-based secondary batteries; Carbons as substrate materials for catalysis and electrocatalysis; Boron-doped diamond film electrodes; and Electrochemical characterization and electrosynthesis of fullerenes and fullerene-type materials. Abstracts of the presentations are presented.

  20. Application of Nuclear Microprobes towards Understanding Complex Ore Geo-electrochemistry

    Directory of Open Access Journals (Sweden)

    Szymanski R.

    2012-10-01

    Full Text Available We report on recent development on the CSIRO Nuclear Microprobe (NMP towards catering for long exposure mapping required for large area scanning. A new data collection system based on Labview FPGA highly co-ordinated with beam transport sits at the heart of the upgrade. These upgrades are discussed and an example of the systems use for μ-Particle Induced X-ray Emission (PIXE analysis in the area of complex ore geo-electrochemistry is briefly described.

  1. Power Ultrasound in Electrochemistry From Versatile Laboratory Tool to Engineering Solution

    CERN Document Server

    Pollet, Bruno

    2012-01-01

    The use of power ultrasound to promote industrial electrochemical processes, or sonoelectrochemistry, was first discovered over 70 years ago, but recently there has been a revived interest in this field. Sonoelectrochemistry is a technology that is safe, cost-effective, environmentally friendly and energy efficient compared to other conventional methods.? The book contains chapters on the following topics, contributed from leading researchers in academia and industry:?Use of electrochemistry as a tool to investigate Cavitation Bubble DynamicsSonoelectroanalysisSonoelectrochemistry in environme

  2. Achieving direct electrochemistry of glucose oxidase by one step electrochemical reduction of graphene oxide and its use in glucose sensing

    Energy Technology Data Exchange (ETDEWEB)

    Shamsipur, Mojtaba; Amouzadeh Tabrizi, Mahmoud, E-mail: mahmoud.tabrizi@gmail.com

    2014-12-01

    In this paper, the direct electrochemistry of glucose oxidase (GOD) was accomplished at a glassy carbon electrode modified with electrochemically reduced graphene oxide/sodium dodecyl sulfate (GCE/ERGO/SDS). A pair of reversible peaks is exhibited on GCE/ERGO/SDS/GOD by cyclic voltammetry. The peak-to-peak potential separation of immobilized GOD is 28 mV in 0.1 M phosphate buffer solution (pH 7.0) with a scan rate of 50 mV/s. The average surface coverage is 2.62 × 10{sup −10} mol cm{sup −2}. The resulting biosensor exhibited a good response to glucose with linear range from 1 to 8 mM (R{sup 2} = 0.9878), good reproducibility and detection limit of 40.8 μM. The results from the biosensor were similar (± 5%) to those obtained from the clinical analyzer. - Highlights: • A direct electron transfer reaction of glucose oxidase was observed on GCE/ERGO/SDS. • This composite film was successfully applied in preparation of glucose biosensor. • The detection limit of the biosensor was estimated to be 40.8 μM. • The results from the sensor were similar to those obtained from the clinical analyzer.

  3. Application of N-doped graphene modified carbon ionic liquid electrode for direct electrochemistry of hemoglobin

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei, E-mail: swyy26@hotmail.com [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Dong, Lifeng, E-mail: donglifeng@qust.edu.cn [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Department of Physics, Astronomy, and Materials Science, Missouri State University, Springfield, MO 65897 (United States); Deng, Ying; Yu, Jianhua [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Wang, Wencheng [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Zhu, Qianqian [College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)

    2014-06-01

    Nitrogen-doped graphene (NG) was synthesized and used for the investigation on direct electrochemistry of hemoglobin (Hb) with a carbon ionic liquid electrode as the substrate electrode. Due to specific characteristics of NG such as excellent electrocatalytic property and large surface area, direct electron transfer of Hb was realized with enhanced electrochemical responses appearing. Electrochemical behaviors of Hb on the NG modified electrode were carefully investigated with the electrochemical parameters calculated. The Hb modified electrode exhibited excellent electrocatalytic reduction activity toward different substrates, such as trichloroacetic acid and H{sub 2}O{sub 2}, with wider dynamic range and lower detection limit. These findings show that NG can be used for the preparation of chemically modified electrodes with improved performance and has potential applications in electrochemical sensing. - Graphical abstract: The utilization of N-doped graphene enables direct electrochemistry of hemoglobin with a pair of well-defined redox peaks appearing. - Highlights: • Nitrogen-doped graphene (NG) was synthesized by a solvothermal method. • NG was used for the investigation on direct electrochemistry of hemoglobin with carbon ionic liquid electrode. • The Hb modified electrode exhibited excellent electrocatalytic activity toward different substrates.

  4. Electrochemistry in the mimicry of oxidative drug metabolism by cytochrome P450s.

    Science.gov (United States)

    Nouri-Nigjeh, Eslam; Bischoff, Rainer; Bruins, Andries P; Permentier, Hjalmar P

    2011-05-01

    Prediction of oxidative drug metabolism at the early stages of drug discovery and development requires fast and accurate analytical techniques to mimic the in vivo oxidation reactions by cytochrome P450s (CYP). Direct electrochemical oxidation combined with mass spectrometry, although limited to the oxidation reactions initiated by charge transfer, has shown promise in the mimicry of certain CYP-mediated metabolic reactions. The electrochemical approach may further be utilized in an automated manner in microfluidics devices facilitating fast screening of oxidative drug metabolism. A wide range of in vivo oxidation reactions, particularly those initiated by hydrogen atom transfer, can be imitated through the electrochemically-assisted Fenton reaction. This reaction is based on O-O bond activation in hydrogen peroxide and oxidation by hydroxyl radicals, wherein electrochemistry is used for the reduction of molecular oxygen to hydrogen peroxide, as well as the reduction of Fe(3+) to Fe(2+). Metalloporphyrins, as surrogates for the prosthetic group in CYP, utilizing metallo-oxo reactive species, can also be used in combination with electrochemistry. Electrochemical reduction of metalloporphyrins in solution or immobilized on the electrode surface activates molecular oxygen in a manner analogous to the catalytical cycle of CYP and different metalloporphyrins can mimic selective oxidation reactions. Chemoselective, stereoselective, and regioselective oxidation reactions may be mimicked using electrodes that have been modified with immobilized enzymes, especially CYP itself. This review summarizes the recent attempts in utilizing electrochemistry as a versatile analytical and preparative technique in the mimicry of oxidative drug metabolism by CYP.

  5. Analysis of cysteine-containing proteins using precolumn derivatization with N-(2-ferroceneethyl)maleimide and liquid chromatography/electrochemistry/mass spectrometry.

    Science.gov (United States)

    Seiwert, Bettina; Karst, Uwe

    2007-08-01

    N-(2-ferroceneethyl)maleimide (FEM) is introduced as an electroactive derivatizing agent for thiol functionalities in proteins. Using appropriate reaction conditions, the derivatization is completed within five minutes and no unspecific labeling of free amino functions is observed. Liquid chromatography/electrochemistry/mass spectrometry was used to detect the reaction products. The reagent is a useful tool for determining the number of free thiol groups or the total number of free and disulfide-bound thiol groups in proteins. The electrochemical cell provides additional information, because the increase in mass spectrometric response upon electrochemical oxidation of the neutral ferrocene to the charged ferrocinium groups is monitored. The method was successfully applied to the analysis of native proteins and their tryptic digests.

  6. Metabolite identification of a radiotracer by electrochemistry coupled to liquid chromatography with mass spectrometric and radioactivity detection.

    Science.gov (United States)

    Baumann, Anne; Faust, Andreas; Law, Marylin P; Kuhlmann, Michael T; Kopka, Klaus; Schäfers, Michael; Karst, Uwe

    2011-07-01

    Radioligands, which specifically bind to a receptor or enzyme (target), enable molecular imaging of the target expression by positron emission tomography (PET). One very promising PET tracer is (S)-1-(4-(2-[(18)F]-fluoroethoxy)benzyl)-5-[1-(2-methoxymethylpyrrolidinyl)sulfonyl]isatin (isatin), a caspase-3 inhibitor, which has been developed at the University Hospital of Münster to image cell death (apoptosis). The translation of this novel tracer from preclinical evaluation to clinical examinations requires biodistribution studies, which characterize the pharmakodynamics and metabolic fate of the compound. This information is used to further optimize the radioligands and to interpret radioactive signals from tissues upon injection of the radioligand in vivo with respect to their specificity. The analysis of the metabolism of radioligands is hampered by the low amount of the compound being typically injected (nano/picomolar amount per injection). In the present study, electrochemistry (EC) is applied to elucidate the oxidative metabolism pathway of the radiotracer. Previous studies have demonstrated that EC can be utilized as a complementary tool to conventional in vitro approaches in drug metabolism studies. Thereby, potential oxidative metabolites of the isatin are determined by EC coupled to electrospray ionization mass spectrometry (EC/ESI-MS). Moreover, using EC/liquid chromatography (LC) and ESI-ion trap MS(n), structural elucidation of the oxidation products is performed. Comparatively to EC, in vitro metabolism studies with rat liver microsomes are conducted. Finally, the developed LC/ESI-MS method is applied to determine metabolites in body fluids and cell extracts from in vivo studies with the nonradioactive ((19)F) and radioactive isatin ((18)F). On the basis of the electrochemically generated oxidation products of the radioligand, the major radioactive metabolite occurring in vivo was successfully identified.

  7. 石墨烯电化学研究进展%Research progress of graphene-based electrochemistry

    Institute of Scientific and Technical Information of China (English)

    孟越; 王林萍; 黄毅; 黄钊; 陈超; 谭月明; 傅迎春; 谢青季

    2014-01-01

    该文简要综述了石墨烯电化学研究的最新进展,包括石墨烯与电分析、石墨烯与能源电化学以及基于石墨烯的光透电极等内容,引用文献88篇。%In this article, we briefly review the recent research progress of graphene-based electrochemistry, in-volving graphene in electroanalysis, graphene in energy electrochemistry and graphene-based optically transparent electrodes, with 88 literatures cited.

  8. Research progress in tribo-electrochemistry and tribo-electrochemical polishing

    Institute of Scientific and Technical Information of China (English)

    ZHAI Wenjie

    2007-01-01

    In this paper, the status quo and recent progress in the research on tribo-electrochemistry in aqueous and non-aqueous media, respectively, are reviewed. Much more attention has been paid to the tribo-electrochemical mechanisms for the control of friction and wear. Based on a summary of the conventional polishing principles of hard and brittle materials, the tribo-electrochemical polishing method is proposed. The results of the preliminary test show that tribo-electrochemical polishing is promising to become a critical technology in the high efficient polishing and planarization of microelectronic materials.

  9. Hydrogen Peroxide Biosensor Based on the Direct Electrochemistry of Myoglobin Immobilized in Poly-3-Hydroxybutyrate Film

    Directory of Open Access Journals (Sweden)

    Xiang Ma

    2005-01-01

    Full Text Available Direct electrochemistry of myoglobin (Mb was observed in a stable film composed of a natural lipid polymer (poly-3-hydroxybutyrate and Mb, the film of which was modified on a pyrolytic graphite electrode. The apparent formal potential of Mb was at about -260 mV in an acetate buffer solution with pH 5.0. Moreover, Mb in the polymer film exhibited catalytic activity towards the reduction of hydrogen peroxide (H2O2. Consequently, an unmediated biosensor for H2O2 was prepared with a linear range from 1.0×10-7 to 4.0×10-4 M.

  10. Direct Electrochemistry of Catalase on Single Wall Carbon Nanotubes Modified Glassy Carbon Electrode

    Institute of Scientific and Technical Information of China (English)

    Qiang ZHAO; Lun Hui GUAN; Zhen Nan GU; Qian Kun ZHUANG

    2005-01-01

    Direct electrochemistry of catalase (Ct) has been studied on single wall carbon nanotubes (SWNTs) modified glassy carbon (GC) electrode. A pair of well-defined nearly reversible redox peaks is given at --0.48 V (vs. SCE) in 0.1 mol/L phosphate solution (pH 7.0).The peak current in cyclic voltammogram is proportional to the scan rate. The peak potential of catalase is shifted to more negative value when the pH increases. Catalase can adsorb on the SWNTs modified electrode.

  11. Exploiting the versatility and selectivity of Mo enzymes with electrochemistry.

    Science.gov (United States)

    Bernhardt, Paul V

    2011-02-14

    This article covers recent advances in the electrochemical study of the mononuclear molybdenum enzymes. Virtually all of these enzymes catalyse a coupled 2-electron, O-atom transfer reaction on a substrate of either organic or inorganic origin. There is a remarkable commonality in structure, function and mechanism of the mononuclear Mo enzymes despite the diversity of their substrates; many that are important to environmental monitoring, food quality control and biomedical science. Mo enzymes routinely oxidise or reduce otherwise inert substrates for which there exist no rapid, simple and reliable analytical methods for their determination and as such represent a potentially rich source of proteins that may be applied in electrochemical biosensors.

  12. Electrochemistry in hollow-channel paper analytical devices.

    Science.gov (United States)

    Renault, Christophe; Anderson, Morgan J; Crooks, Richard M

    2014-03-26

    In the present article we provide a detailed analysis of fundamental electrochemical processes in a new class of paper-based analytical devices (PADs) having hollow channels (HCs). Voltammetry and amperometry were applied under flow and no flow conditions yielding reproducible electrochemical signals that can be described by classical electrochemical theory as well as finite-element simulations. The results shown here provide new and quantitative insights into the flow within HC-PADs. The interesting new result is that despite their remarkable simplicity these HC-PADs exhibit electrochemical and hydrodynamic behavior similar to that of traditional microelectrochemical devices.

  13. The application of electrochemistry to pharmaceutical stability testing--comparison with in silico prediction and chemical forced degradation approaches.

    Science.gov (United States)

    Torres, Susana; Brown, Roland; Szucs, Roman; Hawkins, Joel M; Zelesky, Todd; Scrivens, Garry; Pettman, Alan; Taylor, Mark R

    2015-11-10

    The aim of this study was to evaluate the use of electrochemistry to generate oxidative degradation products of a model pharmaceutical compound. The compound was oxidized at different potentials using an electrochemical flow-cell fitted with a glassy carbon working electrode, a Pd/H2 reference electrode and a titanium auxiliary electrode. The oxidative products formed were identified and structurally characterized by LC-ESI-MS/MS using a high resolution Q-TOF mass spectrometer. Results from electrochemical oxidation using electrolytes of different pH were compared to those from chemical oxidation and from accelerated stability studies. Additionally, oxidative degradation products predicted using an in silico commercially available software were compared to those obtained from the various experimental methods. The electrochemical approach proved to be useful as an oxidative stress test as all of the final oxidation products observed under accelerated stability studies could be generated; previously reported reactive intermediate species were not observed most likely because the electrochemical mechanism differs from the oxidative pathway followed under accelerated stability conditions. In comparison to chemical degradation tests electrochemical degradation has the advantage of being much faster and does not require the use of strong oxidizing agents. Moreover, it enables the study of different operating parameters in short periods of time and optimisation of the reaction conditions (pH and applied potential) to achieve different oxidative products mixtures. This technique may prove useful as a stress test condition for the generation of oxidative degradation products and may help accelerate structure elucidation and development of stability indicating analytical methods.

  14. Flavonoid electrochemistry: a review on the electroanalytical applications

    Directory of Open Access Journals (Sweden)

    Eric S. Gil

    2013-06-01

    Full Text Available Flavonoids are polyphenolic compounds widespread in vegetal kingdom. They present a C-15 skeleton, which is divided into three units A, B and C. Unit C is an oxygen containing heterocyclic, whose oxidation state and saturation level define major subclasses. Units A and B are aromatic rings, in which four major types of substituents, i. e. hydroxyl, methoxyl, prenyl and glycosides, lead to over 8000 different flavonoids. The great healthy-protecting value of these phytochemical biomarkers has attracted the attention of scientific community. Their main biological actions include anticancer and anti-inflammatory properties, which are strictly linked to antioxidant activities. So that, electroanalysis have been extensively applied on mechanistic studies and also for analytical determinations. This review presents the state of the art regarding the main applications of electroanalysis on the flavonoid research. The approaches on redox behavior characterization leading to a better understanding of structure antioxidant activity relationships are highlighted.

  15. Metal-air batteries: from oxygen reduction electrochemistry to cathode catalysts.

    Science.gov (United States)

    Cheng, Fangyi; Chen, Jun

    2012-03-21

    Because of the remarkably high theoretical energy output, metal-air batteries represent one class of promising power sources for applications in next-generation electronics, electrified transportation and energy storage of smart grids. The most prominent feature of a metal-air battery is the combination of a metal anode with high energy density and an air electrode with open structure to draw cathode active materials (i.e., oxygen) from air. In this critical review, we present the fundamentals and recent advances related to the fields of metal-air batteries, with a focus on the electrochemistry and materials chemistry of air electrodes. The battery electrochemistry and catalytic mechanism of oxygen reduction reactions are discussed on the basis of aqueous and organic electrolytes. Four groups of extensively studied catalysts for the cathode oxygen reduction/evolution are selectively surveyed from materials chemistry to electrode properties and battery application: Pt and Pt-based alloys (e.g., PtAu nanoparticles), carbonaceous materials (e.g., graphene nanosheets), transition-metal oxides (e.g., Mn-based spinels and perovskites), and inorganic-organic composites (e.g., metal macrocycle derivatives). The design and optimization of air-electrode structure are also outlined. Furthermore, remarks on the challenges and perspectives of research directions are proposed for further development of metal-air batteries (219 references).

  16. Direct electrochemistry behavior of Cytochrome c on silicon dioxide nanoparticles-modified electrode

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A newfangled direct electrochemistry behavior of Cytochrome c (Cyt c) was found on glassy carbon (GC) electrode modified with the silicon dioxide (SiO2) nanoparticles by physical adsorption. A pair of stable and well-defined redox peaks of Cyt c′ quasi-reversible electrochemical reaction were obtained with a heterogeneous electron transfer rate constant of 1.66×10-3 cm/s and a formal potential of 0.069 V (vs. Ag/AgCl) (0.263 V versus NHE) in 0.1 mol/L pH 6.8 PBS. Both the size and the amount of SiO2 nanoparticles could influence the electron transfer between Cyt c and the electrode. Electrostatic interaction which is between the negative nanoparticle surface and positively charged amino acid residues on the Cyt c surface is of importance for the stability and reproducibility toward the direct electron transfer of Cyt c. It is suggested that the modification of SiO2 nanoparticles proposes a novel approach to realize the direct electrochemistry of proteins.

  17. Direct electrochemistry and Raman spectroscopy of sol-gel-encapsulated myoglobin.

    Science.gov (United States)

    Ray, Anandhi; Feng, Manliang; Tachikawa, Hiroyasu

    2005-08-02

    The direct electrochemistry of myoglobin (Mb) has been observed at a glassy carbon (GC) electrode coated with silica sol-gel-encapsulated Mb film. A well-behaved cyclic voltammogram is observed with a midpoint potential (E(1/2)) of -0.25 V vs Ag/AgCl in a pH 7.0 phosphate buffer. This potential, which is pH-dependent, is 70-90 mV more negative than the formal potential values obtained by using the spectroeletrochemical titration method at the same pH. Square wave voltametry (SWV) also shows a peak potential of -0.25 V for the reduction of Mb under the same experimental conditions. Both cathodic and anodic peak currents have a linear relationship with the scan rate. The midpoint potential decreases with pH, having a slope of -30 mV/pH. UV-vis and resonance Raman spectroscopic studies reveal that the sol-gel provides a bio-compatible environment where Mb retains a structure similar to its solution form, a 6-coordinated aquomet myoglobin. These results suggest that the silica sol-gel is a useful matrix for studying direct electrochemistry of other heme proteins.

  18. Merits of online electrochemistry liquid sample desorption electrospray ionization mass spectrometry (EC/LS DESI MS).

    Science.gov (United States)

    Looi, Wen Donq; Brown, Blake; Chamand, Laura; Brajter-Toth, Anna

    2016-03-01

    A new online electrochemistry/liquid sample desorption electrospray ionization mass spectrometry (EC/LS DESI MS) system with a simple electrochemical thin-layer flow-through cell was developed and tested using N,N-dimethyl-p-phenylenediamine (DMPA) as a model probe. Although oxidation of DMPA is observed as a result of ionization of LS in positive ion mode LS DESI, application of voltage to the online electrochemical (EC) cell in EC/LS DESI MS increases yields of oxidation products. An advantage of LS DESI MS is its sensitivity in aqueous electrolyte solutions, which improves efficiency of electrochemical reactions in EC/LS DESI MS. In highly conductive low pH aqueous buffer solutions, oxidation efficiency is close to 100%. EC/ESI MS typically requires mixed aqueous/organic solvents and low electrolyte concentrations for efficient ionization in MS, limiting efficiency of electrochemistry online with MS. Independently, the results verify higher electrochemical oxidation efficiency during positive mode ESI than during LS DESI.

  19. Integration of electrochemistry in micro-total analysis systems for biochemical assays: recent developments.

    Science.gov (United States)

    Xu, Xiaoli; Zhang, Song; Chen, Hui; Kong, Jilie

    2009-11-15

    Micro-total analysis systems (microTAS) integrate different analytical operations like sample preparation, separation and detection into a single microfabricated device. With the outstanding advantages of low cost, satisfactory analytical efficiency and flexibility in design, highly integrated and miniaturized devices from the concept of microTAS have gained widespread applications, especially in biochemical assays. Electrochemistry is shown to be quite compatible with microanalytical systems for biochemical assays, because of its attractive merits such as simplicity, rapidity, high sensitivity, reduced power consumption, and sample/reagent economy. This review presents recent developments in the integration of electrochemistry in microdevices for biochemical assays. Ingenious microelectrode design and fabrication methods, and versatility of electrochemical techniques are involved. Practical applications of such integrated microsystem in biochemical assays are focused on in situ analysis, point-of-care testing and portable devices. Electrochemical techniques are apparently suited to microsystems, since easy microfabrication of electrochemical elements and a high degree of integration with multi-analytical functions can be achieved at low cost. Such integrated microsystems will play an increasingly important role for analysis of small volume biochemical samples. Work is in progress toward new microdevice design and applications.

  20. Effects of Lecture Method Supplemented with Music and Computer Animation on Senior Secondary School Students' Academic Achievement in Electrochemistry

    Science.gov (United States)

    Akpoghol, T. V.; Ezeudu, F. O.; Adzape, J. N.; Otor, E. E.

    2016-01-01

    The study investigated the effects of Lecture Method Supplemented with Music (LMM) and Computer Animation (LMC) on senior secondary school students' academic achievement in electrochemistry in Makurdi metropolis. Six research questions and six hypotheses guided the study. The design of the study was quasi experimental, specifically the pre-test,…

  1. Direct electrochemistry of Penicillium chrysogenum catalase adsorbed on spectroscopic graphite.

    Science.gov (United States)

    Dimcheva, Nina; Horozova, Elena

    2013-04-01

    The voltammetric studies of Penicillium chrysogenum catalase (PcCAT) adsorbed on spectroscopic graphite, showed direct electron transfer (DET) between its active site and the electrode surface. Analogous tests performed with the commercially available bovine catalase revealed that mammalian enzyme is much less efficient in the DET process. Both catalases were found capable to catalyse the electrooxidation of phenol, but differed in the specifics of catalytic action. At an applied potential of 0.45V the non-linear regression showed the kinetics of the bioelectrochemical oxidation catalysed by the PcCAT obeyed the Hill equation with a binding constant K=0.034±0.002 M(2) (Hill's coefficient n=2.097±0.083, R(2)=0.997), whilst the catalytic action of the bovine catalase was described by the Michaelis-Menten kinetic model with the following parameters: V(max,app)=7.780±0.509 μA, and K(M,app)=0.068±0.070 mol L(-1). The performance of the electrode reaction was affected by the electrode potential, the pH, and temperature. Based on the effect of pH and temperature on the electrode response in presence of phenol a tentative reaction pathway of its bioelectrocatalytic oxidation has been hypothesised. The possible application of these findings in biosensing phenol up to concentration 30 mM at pHs below 7 and in absence of oxidising agents (oxygen or H(2)O(2)) was considered.

  2. Na-Ion Battery Anodes: Materials and Electrochemistry.

    Science.gov (United States)

    Luo, Wei; Shen, Fei; Bommier, Clement; Zhu, Hongli; Ji, Xiulei; Hu, Liangbing

    2016-02-16

    also outlined, where graphene oxide was employed as dehydration agent and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was used to unzip wood fiber. Furthermore, surface modification by atomic layer deposition technology is introduced, where we discover that a thin layer of Al2O3 can function to encapsulate Sn nanoparticles, leading to a much enhanced cycling performance. We also highlight recent work about the phosphorene/graphene anode, which outperformed other anodes in terms of capacity. The aromatic organic anode is also studied as anode with very high initial sodiation capacity. Furthermore, electrochemical intercalation of Na ions into reduced graphene oxide is applied for fabricating transparent conductors, demonstrating the great feasibility of Na ion intercalation for optical applications.

  3. Electrochemistry-mass spectrometry for in-vitro determination of selected chemotherapeutics and their electrochemical products in comparison to in-vivo approach.

    Science.gov (United States)

    Szultka-Mlynska, Malgorzata; Buszewski, Boguslaw

    2016-11-01

    Chemotherapeutics are among the most frequently prescribed medications in modern medicine. They are widely prescribed; however, problems with organisms developing resistance to these drugs means that their efficacy may be lost, so care should be taken to avoid unnecessary prescription. It is therefore of great interest to study the detailed metabolism of these biologically active compounds. This study aimed at developing an efficient analytical protocol for the determination of in-vitro electrochemical products of selected antibiotic drugs (amoxicillin, cefotaxime, fluconazole, linezolid, metronidazole and moxifloxacin). Combination of electrochemistry (EC) and mass spectrometry (MS) was applied for the in-vitro determination of the studied antibiotics and their electrochemical products. To identify the structure of the detected electrochemical products, MS/MS experiments were performed. This was one of the first applications of the EC system for generation of electrochemical products produced from antibiotic drugs. Adjustment of appropriate conditions and such parameters as the potential value, mobile phase (pH), working electrode and temperature had significant influence on electrochemical simulations and the creation of selected derivatives. Consequently, several working electrodes were evaluated for this purpose. In most of the studied cases, mainly two types of products were observed. One corresponded to an increase in mass by 14Da, which can be explained by a process consisting of oxidation (+16 m/z) and dehydrogenation (-2 m/z); The second in turn showed mass reduction by 14Da, which can be attributed to the loss of -CH2 as a result of N-demethylation. The performed experiments consisted of two stages: electrochemical oxidation of the analyzed samples (phase I of metabolic transformation), and addition of glutathione (GSH) for follow-up reactions (phase II conjunction). The electrochemical results were compared to in-vivo experiments by analyzing urine

  4. Critical transport rates that limit the performance of microbial electrochemistry technologies.

    Science.gov (United States)

    Popat, Sudeep C; Torres, César I

    2016-09-01

    Microbial electrochemistry technologies (METs) take advantage of the connection of microorganisms with electrodes. In the classic case of a microbial anode, the maximization of current density produced is often the goal. But, current production is dependent on many transport processes occurring, which can be rate-limiting. These include the fluxes of electron donor and acceptor, the ionic flux, the acidity and alkalinity fluxes at anode and cathode respectively, the electron transport flux at the biofilm, and the reactant/product crossover flux. Associated with these fluxes are inherent concentration gradients that can affect performance. This critical review provides an analysis on how these transport processes have hindered the development of METs, and how MET designs have evolved as more knowledge of these transport limitations is gained. Finally, suggestions are provided on how to design MET systems taking into consideration critical transport processes that are intimately linked to the current produced.

  5. Immobilization and direct electrochemistry of copper-containing enzymes on active carbon

    Institute of Scientific and Technical Information of China (English)

    SUN Dongmei; CAI Chenxin; XING Wei; LU Tianhong

    2004-01-01

    Two typical and important copper-containing enzymes, laccase (Lac) and tyrosinase (Tyr), have been immobilized on the surface of active carbon with simple adsorption method. The cyclic voltammetric results indicated that the active carbon could promote the direct electron transfer of both Lac and Tyr and a pair of well-defined and nearly symmetric redox peaks appeared on the cyclic voltammograms of Lac or Tyr with the formal potential, E0′, independent on the scan rate. The further experimental results showed that the immobilized copper-containing oxidase displayed an excellent electrocatalytic activity to the electrochemical reduction of O2. The immobilization method presented here has several advantages, such as simplicity, easy to operation and keeping good activity of enzyme etc., and could be further used to study the direct electrochemistry of other redox proteins and enzymes and fabricate the catalysts for biofuel cell.

  6. In Situ, Real-Time Visualization of Electrochemistry Using Magnetic Resonance Imaging.

    Science.gov (United States)

    Britton, Melanie M; Bayley, Paul M; Howlett, Patrick C; Davenport, Alison J; Forsyth, Maria

    2013-09-05

    The drive to develop better electrochemical energy storage devices requires the development of not only new materials, but also better understanding of the underpinning chemical and dynamical processes within such devices during operation, for which new analytical techniques are required. Currently, there are few techniques that can probe local composition and transport in the electrolyte during battery operation. In this paper, we report a novel application of magnetic resonance imaging (MRI) for probing electrochemical processes in a model electrochemical cell. Using MRI, the transport and zinc and oxygen electrochemistry in an alkaline electrolyte, typical of that found in zinc-air batteries, are investigated. Magnetic resonance relaxation maps of the electrolyte are used to visualize the chemical composition and electrochemical processes occurring during discharge in this model metal-air battery. Such experiments will be useful in the development of new energy storage/conversion devices, as well as other electrochemical technologies.

  7. In-situ Raman spectroscopy to elucidate the influence of adsorption in graphene electrochemistry

    Science.gov (United States)

    van den Beld, Wesley T. E.; Odijk, Mathieu; Vervuurt, René H. J.; Weber, Jan-Willem; Bol, Ageeth A.; van den Berg, Albert; Eijkel, Jan C. T.

    2017-01-01

    Electrochemistry on graphene is of particular interest due to graphene’s high surface area, high electrical conductivity and low interfacial capacitance. Because the graphene Fermi level can be probed by its strong Raman signal, information on the graphene doping can be obtained which in turn can provide information on adsorbed atoms or molecules. For this paper, the adsorption analysis was successfully performed using three electroactive substances with different electrode interaction mechanisms: hexaammineruthenium(III) chloride (RuHex), ferrocenemethanol (FcMeOH) and potassium ferricyanide/potassium ferrocyanide (Fe(CN)6). The adsorption state was probed by analysing the G-peak position in the measured in-situ Raman spectrum during electrochemical experiments. We conclude that electrochemical Raman spectroscopy on graphene is a valuable tool to obtain in-situ information on adsorbed species on graphene, isolated from the rest of the electrochemical behaviour. PMID:28338094

  8. Ubiquitous trisulfur radical anion: fundamentals and applications in materials science, electrochemistry, analytical chemistry and geochemistry.

    Science.gov (United States)

    Chivers, Tristram; Elder, Philip J W

    2013-07-21

    The trisulfur radical anion [S3]˙(-) is well-known from inorganic chemistry textbooks as the blue chromophore in ultramarine blues in which this highly reactive species is trapped in a zeolitic framework. Recent findings have revealed that [S3]˙(-) has a multi-faceted role in a variety of media, including alkali metal-sulfur batteries, aqueous solutions at high temperatures and pressures, and ionic liquids; it has also been used to detect trace amounts of water in organic solvents. This tutorial review illustrates how various physical techniques are used to identify a reactive species in solution and shows how elucidation of electronic structures can be used to explain spectroscopic and structural properties. Examples of the function of [S3]˙(-) in materials science, electrochemistry, analytical chemistry and geochemistry are used to illustrate the widespread influence of this fundamentally important triatomic sulfur species.

  9. Direct Electrochemistry of Glucose Oxidase at a Gold Electrode Modified with Single-Wall Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Yuan Zhuobin

    2003-12-01

    Full Text Available The direct electrochemistry of glucose oxidase (GOD was accomplished at a gold electrode modified with single-wall carbon nanotubes (SWNTs. A pair of welldefined redox peaks was obtained for GOD with the reduction peak potential at –0.465 V and a peak potential separation of 23 mV at pH 7.0. Both FT-IR spectra and the dependence of the reduction peak current on the scan rate revealed that GOD adsorbed onto the SWNT surfaces. The redox wave corresponds to the redox center of the flavin adenine dinucleotide(FAD of the GOD adsorbate. The electron transfer rate of GOD redox reaction was greatly enhanced at the SWNT-modified electrode. The peak potential was shown to be pH dependent. Verified by spectral methods, the specific enzyme activity of GOD adsorbates at the SWNTs appears to be retained.

  10. Electrochemistry at the edge of a single graphene layer in a nanopore

    DEFF Research Database (Denmark)

    Banerjee, Sutanuka; Shim, Jeong; Rivera, J.;

    2013-01-01

    We study the electrochemistry of single layer graphene edges using a nanopore-based structure consisting of stacked graphene and AlO dielectric layers. Nanopores, with diameters ranging from 5 to 20 nm, are formed by an electron beam sculpting process on the stacked layers. This leads to a unique...... edge structure which, along with the atomically thin nature of the embedded graphene electrode, demonstrates electrochemical current densities as high as 1.2 × 10 A/cm. The graphene edge embedded structure offers a unique capability to study the electrochemical exchange at an individual graphene edge......, isolated from the basal plane electrochemical activity. We also report ionic current modulation in the nanopore by biasing the embedded graphene terminal with respect to the electrodes in the fluid. The high electrochemical specific current density for a graphene nanopore-based device can have many...

  11. Functionalizing Arrays of Transferred Monolayer Graphene on Insulating Surfaces by Bipolar Electrochemistry

    DEFF Research Database (Denmark)

    Koefoed, Line; Pedersen, Emil Bjerglund; Thyssen, Lena

    2016-01-01

    graphene sheets supported on SiO2. Using this technique, transferred graphene can be electrochemically functionalized without the need of a metal support or the deposition of physical contacts. X-ray photoelectron spectroscopy and Raman spectroscopy are used to map the chemical changes and modifications....... Furthermore, it is shown that it is possible to simultaneously modify an array of many small graphene electrodes (1 × 1 mm2) on SiO2.......Development of versatile methods for graphene functionalization is necessary before use in applications such as composites or as catalyst support. In this study, bipolar electrochemistry is used as a wireless functionalization method to graft 4-bromobenzenediazonium on large (10 × 10 mm2) monolayer...

  12. Electrochemistry of single metalloprotein and DNA-based molecules at Au(111) electrode surfaces.

    Science.gov (United States)

    Salvatore, Princia; Zeng, Dongdong; Karlsen, Kasper K; Chi, Qijin; Wengel, Jesper; Ulstrup, Jens

    2013-07-22

    We have briefly overviewed recent efforts in the electrochemistry of single transition metal complex, redox metalloprotein, and redox-marked oligonucleotide (ON) molecules. We have particularly studied self-assembled molecular monolayers (SAMs) of several 5'-C6-SH single- (ss) and double-strand (ds) ONs immobilized on Au(111) electrode surfaces via Au-S bond formation, using a combination of nucleic acid chemistry, electrochemistry and electrochemically controlled scanning tunnelling microscopy (in situ STM). Ds ONs stabilized by multiply charged cations and locked nucleic acid (LNA) monomers have been primary targets, with a view on stabilizing the ds-ONs and improving voltammetric signals of intercalating electrochemical redox probes. Voltammetric signals of the intercalator anthraquinone monosulfonate (AQMS) at ds-DNA/Au(111) surfaces diluted by mercaptohexanol are significantly sharpened and more robust in the presence than in the absence of [Co(NH3)6](3+). AQMS also displays robust Faradaic voltammetric signals specific to the ds form on binding to similar LNA/Au(111) surfaces, but this signal only evolves after successive voltammetric scanning into negative potential ranges. Triply charged spermidine (Spd) invokes itself a strong voltammetric signal, which is specific to the ds form and fully matched sequences. This signal is of non-Faradaic, capacitive origin but appears in the same potential range as the Faradaic AQMS signal. In situ STM shows that molecular scale structures of the size of Spd-stabilized ds-ONs are densely packed over the Au(111) surface in potential ranges around the capacitive peak potential.

  13. Electrochemistry Experiments to Develop Novel Sensors for Real-World Applications

    Directory of Open Access Journals (Sweden)

    Suzanne Lunsford

    2013-08-01

    Full Text Available These novel STEM (Science Technology Engineering and Mathematics Electrochemistry experiments have been designed to increase the integrated science content, pedagogical, and technological knowledge for real-world applications. This study has focused on (1 the fundamental understanding on the relationship of metal oxide films and polymers to electrochemical sensors, and (2 the development of new materials which have great application of electrode materials. Following the inquiry based learning strategy the research students learn to develop and study the electrode surfaces to meet the needs of stability and low detection limits. Recently, new advances in environmental health are revealing the anthropogenic or naturally occurring harmful organic chemicals in sources of water supply expose a great health threat to human and aquatic life. Due to their well-known carcinogenic and lethal properties, the presence of human produced toxic chemicals such as phenol and its derivatives poses a critical threat to human health and aquatic life in such water resources. In order to achieve effective assessment and monitoring of these toxic chemicals there is a need to develop in-situ (electrochemical sensors methods to detect rapidly. Electrochemical sensors have attracted more attention to analytical chemist and electrochemistry engineers due to its simplicity, rapidness and high sensitivity. However, there will be real challenges of achieving successful analysis of chemicals (phenol in the presence of common interferences in water resources, which will be discussed regarding the students challenging learning experiences in developing an electrochemical sensor. The electrochemical sensor developed (TiO2 , ZrO2 or sol-gel mixture TiO2/ZrO2 will be illustrated and the successes will be shown by cyclic voltammetry data in detection of 1,2-dihydroxybenzenes (catechol, dopamine and phenol.

  14. In-Depth Characterization of Protein Disulfide Bonds by Online Liquid Chromatography-Electrochemistry-Mass Spectrometry

    Science.gov (United States)

    Switzar, Linda; Nicolardi, Simone; Rutten, Julie W.; Oberstein, Saskia A. J. Lesnik; Aartsma-Rus, Annemieke; van der Burgt, Yuri E. M.

    2016-01-01

    Disulfide bonds are an important class of protein post-translational modifications, yet this structurally crucial modification type is commonly overlooked in mass spectrometry (MS)-based proteomics approaches. Recently, the benefits of online electrochemistry-assisted reduction of protein S-S bonds prior to MS analysis were exemplified by successful characterization of disulfide bonds in peptides and small proteins. In the current study, we have combined liquid chromatography (LC) with electrochemistry (EC) and mass analysis by Fourier transform ion cyclotron resonance (FTICR) MS in an online LC-EC-MS platform to characterize protein disulfide bonds in a bottom-up proteomics workflow. A key advantage of a LC-based strategy is the use of the retention time in identifying both intra- and interpeptide disulfide bonds. This is demonstrated by performing two sequential analyses of a certain protein digest, once without and once with electrochemical reduction. In this way, the "parent" disulfide-linked peptide detected in the first run has a retention time-based correlation with the EC-reduced peptides detected in the second run, thus simplifying disulfide bond mapping. Using this platform, both inter- and intra-disulfide-linked peptides were characterized in two different proteins, ß-lactoglobulin and ribonuclease B. In order to prevent disulfide reshuffling during the digestion process, proteins were digested at a relatively low pH, using (a combination of) the high specificity proteases trypsin and Glu-C. With this approach, disulfide bonds in ß-lactoglobulin and ribonuclease B were comprehensively identified and localized, showing that online LC-EC-MS is a useful tool for the characterization of protein disulfide bonds.

  15. Polymerized ionic liquid-wrapped carbon nanotubes: the promising composites for direct electrochemistry and biosensing of redox protein.

    Science.gov (United States)

    Xiao, Chunhui; Chu, Xiaochen; Wu, Bohua; Pang, Haili; Zhang, Xiaohua; Chen, Jinhua

    2010-03-15

    Polymerized ionic liquid-wrapped carbon nanotubes (PIL-CNTs) were firstly designed for direct electrochemistry and biosensing of redox proteins. The CNTs were coated successfully with polymerized ionic liquid (PIL) layer, as verified by transmission electron microscopy (TEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. The PIL-CNTs were dispersed better in water and showed superior electrocatalysis toward O(2) and H(2)O(2) comparing to pristine CNTs and the mixture of IL monomer and CNTs. With glucose oxidase (GOD) as a protein model, the direct electrochemistry of the redox protein was investigated on the PIL-CNTs modified glassy carbon (GC) electrode and excellent direct electrochemical performance of GOD molecules was observed. The proposed biosensor (GOD/PIL-CNTs/GC electrode) displayed good analytical performance for glucose with linear response up to 6mM, response sensitivity of 0.853 microA mM(-1), good stability and selectivity.

  16. The Character of Photo-electrochemistry of Palladium Implanted TiO2 Nano-crystalline Electrode

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new electrode was prepared by using Pd implanted into nano-crystalline TiO2 and the character of photo-electrochemistry of implanted electrodes was investigated. The energy band structure of nano-crystalline TiO2 has not changed after implantation with Pd. The photo-current (iph) of palladium implanted TiO2 nano-crystalline electrode is larger than that of pure TiO2 nano-crystalline electrode.

  17. Direct Electrochemistry of Hemoglobin in Layer-by-layer {PDDA/Hb}n Films Assembled on Pyrolytic Graphite Electrodes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Layer-by-layer {PDDA/Hb}n films were assembled by means of alternate adsorption of positively charged poly(diallyldimethyl ammonium) (PDDA) and negatively charged hemoglobin (Hb) at pH 9.2 from their aqueous solutions on pyrolytic graphite (PG) electrodes. Film growth during adsorption cycles was demonstrated by cyclic voltammetry and UV-Vis spectroscopy.Direct electrochemistry of Hb in {PDDA/Hb} n films on PG was studied.

  18. Application of on-line electrochemistry/electrospray/tandem mass spectrometry to a quantification method for the antipsychotic drug zotepine in human serum.

    Science.gov (United States)

    Nozaki, Kazuyoshi; Osaka, Issey; Kawasaki, Hideya; Arakawa, Ryuichi

    2009-10-01

    A simple, rapid, and sensitive on-line liquid chromatographic electrochemistry/electrospray/tandem mass spectrometry (LC-EC/ESI-MS/MS) method for the determination of zotepine in human serum was developed using a new generated-electrochemically fragment ion, and was validated. A recent novel technique of LC-EC/ESI-MS/MS that combines LC-MS/MS and the on-line EC reaction is potentially applicable to developing a quantification method for drugs in biological samples. Newly formed products generated by the on-line EC cell are expected to provide appropriate precursor and product ions for the MS/MS determination method. This technique was successfully applied to a drug assay in a biological matrix. After adding imipramine (IS) to a 30-microL aliquot of human serum, the resulting sample was simply deproteinated with acetonitrile for a measurement. The analytical run time was 5 min. The calibration curve was linear in the concentration range of 10-2000 ng/mL. The intra-assay precision and accuracy were in the range of 1.8-8.9 and 98.4-113%, respectively.

  19. Electrochemistry of tin in the 1-ethyl-3-methylimidazolium dicyanamide room temperature ionic liquid

    Energy Technology Data Exchange (ETDEWEB)

    Leong, Tin-Iao; Hsieh, Yi-Ting [Department of Chemistry, National Cheng Kung University, Tainan, Taiwan (China); Sun, I-Wen, E-mail: iwsun@mail.ncku.edu.t [Department of Chemistry, National Cheng Kung University, Tainan, Taiwan (China)

    2011-04-15

    Research highlights: {yields} The electrochemistry of Sn(II) was studied in the room temperature ionic liquid 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) on a glassy carbon (GC) and a polycrystalline Pt electrode at 40 {sup o}C. {yields} The Sn(II) species was introduced into the ionic liquid by either dissolution of SnCl{sub 2} or anodizing a Sn wire. {yields} The reduction potential of the Sn(II)/Sn couple produced in these two solutions was found to be different, indicating that different Sn(II) species may be present. {yields} The diffusion coefficient of SnCl{sub 2} dissolved in the EMI-DCA was in the same order of magnitude as those reported for SnCl{sub 2} in several other ionic liquids. {yields} Depending on the deposition potentials, potentiostatic electrolysis produced Sn deposits with various unusual morphologies such as hexagonal tubes, spiral nanowires, and dendrite. - Abstract: The electrochemistry of Sn(II) was studied in the room temperature ionic liquid 1-ethyl-3-methylimidazolium dicyanamide (EMI-DCA) on a glassy carbon (GC) and a polycrystalline Pt electrode at 40 {sup o}C. The Sn(II) species was introduced into the ionic liquid by either dissolution of SnCl{sub 2} or anodizing a Sn wire. The reduction potential of the Sn(II)/Sn couple produced in these two solutions was found to be different, indicating that different Sn(II) species may be present. The order of the reduction potential of the two Sn(II) species indicates that the Gutmann donor ability of the anions is likely to be DCA{sup -} > Cl{sup -}. Cyclic voltammetry indicates the stripping efficiency is >90% on the Pt but only 40% on the GC electrode. Analysis of the chronoamperometric transient behavior during electrodeposition suggests that the deposition of Sn on the GC electrode involves a three dimensional progressive nucleation on a finite number of active sites. The diffusion coefficient of SnCl{sub 2} dissolved in the EMI-DCA was found to be 9.8 x 10{sup -7} cm{sup 2} s

  20. Scopus: A system for the evaluation of scientific journals

    Science.gov (United States)

    Guz, A. N.; Rushchitsky, J. J.

    2009-04-01

    The paper discusses the evaluation of scientific journals based on the Scopus database, information tools, and criteria. The SJR (SCImago Journal Rank) as the main criterion used by Scopus to evaluate scientific journals is considered. The Scopus and ISI systems are compared using information on the journal Prikladnaya Mekhanika ( International Applied Mechanics), a number of world-known journals on mechanics, and some journals on natural sciences issued by the National Academy of Sciences of Ukraine. Some comments and proposals are formulated. This paper may be considered as a follow up on papers published in Prikladnaya Mekhanika ( International Applied Mechanics) in 2005-2009

  1. Wireless Synthesis and Activation of Electrochemiluminescent Thermoresponsive Janus Objects Using Bipolar Electrochemistry.

    Science.gov (United States)

    Phuakkong, Oranit; Sentic, Milica; Li, Haidong; Warakulwit, Chompunuch; Limtrakul, Jumras; Sojic, Neso; Kuhn, Alexander; Ravaine, Valérie; Zigah, Dodzi

    2016-12-13

    In this work, bipolar electrochemistry (BPE) is used as a dual wireless tool to generate and to activate a thermoresponsive electrochemiluminescent (ECL) Janus object. For the first time, BPE allows regioselective growth of a poly(N-isopropylacrylamide) (pNIPAM) hydrogel film on one side of a carbon fiber. It is achieved thanks to the local reduction of persulfate ions, which initiate radical polymerization of NIPAM. By controlling the electric field and the time of the bipolar electrochemical reactions, we are able to control the length and the thickness of the deposit. The resulting pNIPAM film is found to be swollen in water at room temperature and collapsed when heated above 32 °C. We further incorporated a covalently attached ruthenium complex luminophore, Ru(bpy)3(2+), in the hydrogel film. In the second time, BPE is used to activate remotely the electrogenerated chemiluminescence (ECL) of the Ru(bpy)3(2+) moieties in the film. We take advantage of the film responsiveness to amplify the ECL signal. Upon collapse of the film, the ECL signal, which is sensitive to the distance between adjacent Ru(bpy)3(2+) centers, is strongly amplified. It is therefore shown that BPE is a versatile tool to generate highly sophisticated materials based on responsive polymers, which could lead to sensitive sensors.

  2. Detailed H2 and CO Electrochemistry for a MEA Model Fueled by Syngas

    KAUST Repository

    Lee, W. Y.

    2015-07-17

    © The Electrochemical Society. SOFCs can directly oxidize CO in addition to H2, which allows them to be coupled to a gasifier. Many membrane-electrode-assembly (MEA) models neglect CO electrochemistry due to sluggish kinetics and the water-gas-shift reaction, but CO oxidation may be important for high CO-content syngas. The 1D-MEA model presented here incorporates detailed mechanisms for both H2 and CO oxidation, individually fitted to experimental data. These mechanisms are then combined into a single model, which provides a good fit to experimental data for H2/CO mixtures. Furthermore, the model fits H2/CO data best when a single chargetransfer step in the H2 mechanism is assumed to be rate-limiting for all current densities. This differs from the result for H2/H2O mixtures, where H2 adsorption becomes rate-limiting at high current densities. These results indicate that CO oxidation cannot be neglected in MEA models running on CO-rich syngas, and that CO oxidation can alter the H2 oxidation mechanism.

  3. Water as a promoter and catalyst for dioxygen electrochemistry in aqueous and organic media.

    Energy Technology Data Exchange (ETDEWEB)

    Staszak-Jirkovsky, Jakub; Subbaraman, Ram; Strmcnik, Dusan; Harrison, Katherine L.; Diesendruck, Charles E.; Assary, Rajeev; Frank, Otakar; Kobr, Lukas; Wiberg, Gustav K.H; Genorio, Bostjan; Connell, Justin G.; Lopes, Pietro P.; Stamenkovic, Vojislav R.; Curtiss, Larry; Moore, Jeffrey S.; Zavadil, Kevin R.; Markovic, Nenad M.

    2015-11-01

    Water and oxygen electrochemistry lies at the heart of interfacial processes controlling energy transformations in fuel cells, electrolyzers, and batteries. Here, by comparing results for the ORR obtained in alkaline aqueous media to those obtained in ultradry organic electrolytes with known amounts of H2O added intentionally, we propose a new rationale in which water itself plays an important role in determining the reaction kinetics. This effect derives from the formation of HOad center dot center dot center dot H2O (aqueous solutions) and LiO2 center dot center dot center dot H2O (organic solvents) complexes that place water in a configurationally favorable position for proton transfer to weakly adsorbed intermediates. We also find that, even at low concentrations (<10 ppm), water acts simultaneously as a promoter and as a catalyst in the production of Li2O2, regenerating itself through a sequence of steps that include the formation and recombination of H+ and OH-. We conclude that, although the binding energy between metal surfaces and oxygen intermediates is an important descriptor in electrocatalysis, understanding the role of water as a proton-donor reactant may explain many anomalous features in electrocatalysis at metal-liquid interfaces.

  4. Electrochemistry of surface wired cytochrome c and bioelectrocatalytic sensing of superoxide

    Indian Academy of Sciences (India)

    Susmita Behera; Ramendra Sundar Dey; Manas Kumar Rana; C Retna Raj

    2013-03-01

    Electrochemistry of cytochrome c (Cyt-c) wired on an electrode modified with the self-assemblies of 4,4'-dithio-dibutyric acid (DTB) and 2-pyrazineethane thiol (PET) by covalent and electrostatic binding and the amperometric sensing of superoxide (O$^{−}_{2}$) are described. Cyt-c wired on the mixed self-assembly of DTB and PET displays well-defined voltammetric response at 0.025V with a peak-to-peak separation ( ) of 5mV. Pyrazine unit in the mixed self-assembly promotes the electron transfer in the redox reaction of surface wired Cyt-c. Cyt-c wired on the mixed self-assembly has been used for the amperometric sensing of superoxide. The enzymatically generated superoxide has been successfully detected using the Cyt-c wired electrode. High sensitivity and fast response for superoxide have been achieved. Uric acid does not interfere in the amperometric measurement of superoxide. The interference due to H2O2 has been eliminated by using enzyme catalase.

  5. Biomolecular detection at ssDNA-conjugated nanoparticles by nano-impact electrochemistry.

    Science.gov (United States)

    Karimi, Anahita; Hayat, Akhtar; Andreescu, Silvana

    2017-01-15

    We describe the use of ssDNA functionalized silver nanoparticle (AgNP) probes for quantitative investigation of biorecognition and real time detection of biomolecular targets using nano-impact electrochemistry. The method is based on measurements of the individual collision events between ssDNA aptamer-functionalized AgNPs and a carbon fiber miroelectrode (CFME). Specific binding events of target analyte induced collision frequency changes enabling ultrasensitive detection of the aptamer target in a single step. These changes are assigned to the surface coverage of the NP by the ssDNA aptamers and subsequent conformational changes of the aptamer probe which affect the electron transfer between the NP and the electrode surface. The method enables sensitive and selective detection of ochratoxin A (OTA), chosen here as a model target, with a limit of detection of 0.05nM and a relative standard deviation of 4.9%. The study provides a means of characterizing bioconjugation of AgNPs with aptamers and assessing biomolecular recognition events with high sensitivity and without the use of exogenous reagents or enzyme amplification steps. This methodology can be broadly applicable to other bioconjugated systems, biosensing and related bioanalytical applications.

  6. Direct electrochemistry of hemoglobin entrapped in dextran film on carbon ionic liquid electrode

    Indian Academy of Sciences (India)

    Xiaoqing Li; Yan Wang; Xiaoying Sun; Tianrong Zhan; Wei Sun

    2010-03-01

    Direct electrochemistry of hemoglobin (Hb) entrapped in the dextran (De) film on the surface of a room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6) modified carbon paste electrode (CILE) has been investigated. UV-Vis and FT-IR spectroscopy showed that Hb retained its native structure in the De film. Scanning electron microscopy (SEM) indicated an uniform film was formed on the electrode surface. Cyclic voltammetric experiments indicated that the electron transfer efficiency between Hb and the electrode was greatly improved due to the presence of the De film and ionic liquid, which provided a biocompatible and higher conductive interface. A pair of well-defined and quasi-reversible redox peak was obtained with the anodic and cathodic peaks located at -0.195 V and -0.355 V in pH 7.0 phosphate buffer solution, respectively. The electrochemical parameters were calculated by investigating the relationship of the peak potential with the scan rate. The fabricated De/Hb/CILE showed good electrocatalytic ability to the reduction of H2O2 with the linear concentration range from 4.0 × 10-6 to 1.5 × 10-5 mol/L and the apparent Michaelis-Menten constant ($K_{M}^{\\text{app}}$) for the electrocatalytic reaction was calculated as 0.17 M.

  7. Direct Electrochemistry of Horseradish Peroxidase on NiO Nanoflower Modified Electrode and Its Electrocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Lijun Yan

    2016-09-01

    Full Text Available In this paper nickel oxide (NiO nanoflower was synthesized and used for the realization of direct electrochemistry of horseradish peroxidase (HRP. By using carbon ionic liquid electrode (CILE as the substrate electrode, NiO-HRP composite was casted on the surface of CILE with chitosan (CTS as the film forming material and the modified electrode was denoted as CTS/NiO-HRP/CILE. UV-Vis absorption and FT-IR spectra confirmed that HRP retained its native structure after mixed with NiO nanoflower. Direct electron transfer of HRP on the modified electrode was investigated by cyclic voltammetry with a pair of quasi-reversible redox waves appeared, indicating that the presence of NiO nanoflower on the electrode surface could accelerate the electron transfer rate between the electroactive center of HRP and the substrate electrode. Electrochemical behaviors of HRP on the modified electrode were carefully investigated. The HRP modified electrode showed excellent electrocatalytic activity to the reduction of trichloroacetic acid with wider linear range and lower detection limit. Therefore the presence of NiO nanoflower could provide a friendly biocompatible interface for immobilizing biomolecules and keeping their native structure. The fabricated electrochemical biosensor displayed the advantages such as high sensitivity, good reproducibility and long-term stability. This work is licensed under a Creative Commons Attribution 4.0 International License.

  8. Liquid / liquid biphasic electrochemistry in ultra-turrax dispersed acetonitrile / aqueous electrolyte systems

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, John D. [Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom); Amemiya, Fumihiro; Atobe, Mahito [Tokyo Institute of Technology, Department of Electronic Chemistry, Yokohama, Kanagawa 2268502 (Japan); Bulman-Page, Philip C. [School of Chemistry, University of East Anglia, Norwich, Norfolk NR4 7TJ (United Kingdom); Marken, Frank, E-mail: F.Marken@bath.ac.u [Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY (United Kingdom)

    2010-12-01

    Unstable acetonitrile | aqueous emulsions generated in situ with ultra-turrax agitation are investigated for applications in dual-phase electrochemistry. Three modes of operation for liquid / liquid aqueous-organic electrochemical processes are demonstrated with no intentionally added electrolyte in the organic phase based on (i) the formation of a water-soluble product in the aqueous phase in the presence of the organic phase, (ii) the formation of a product and ion transfer at the liquid / liquid-electrode triple phase boundary, and (iii) the formation of a water-insoluble product in the aqueous phase which then transfers into the organic phase. A three-electrode electrolysis cell with ultra-turrax agitator is employed and characterised for acetonitrile / aqueous 2 M NaCl two phase electrolyte. Three redox systems are employed in order to quantify the electrolysis cell performance. The one-electron reduction of Ru(NH{sub 3}){sub 6}{sup 3+} in the aqueous phase is employed to determine the rate of mass transport towards the electrode surface and the effect of the presence of the acetonitrile phase. The one-electron oxidation of n-butylferrocene in acetonitrile is employed to study triple phase boundary processes. Finally, the one-electron reduction of cobalticenium cations in the aqueous phase is employed to demonstrate the product transfer from the electrode surface into the organic phase. Potential applications in biphasic electrosynthesis are discussed.

  9. Direct electrochemistry and electrocatalysis of horseradish peroxidase immobilized on L-glutathione self-assembled monolayers

    Institute of Scientific and Technical Information of China (English)

    Chuan Yin Liu; Ji Ming Hu

    2008-01-01

    A novel hydrogen peroxide biosensor has been fabricated based on covalently linked horseradish peroxidase (HRP) onto Lglutathione self-assembled monolayers (SAMs). The SAMs-based electrode was characterized by electrochemical methods, and direct electrochemistry of HRP can be achieved with formal potential of-0.242 V (vs. saturated Ag/AgCl) in pH7 phosphate buffer solution (PBS), the redox peak current is linear to scan rate and rate constant can be calculated to be 0.042 s-1. The HRP-SAMs-based biosensors show its better electrocatalysis to hydrogen peroxide in the concentration range of 1 × 10-6 mol/L to 1.2 × 10-3 mol/L with a detection limit of 4 × 10-7 mol/L. The apparent Michealis-Menten constant is 3.12 mmol/L. The biosensor can effectively eliminate the interferences of dopamine, ascorbic acid, uric acid, catechol and p-acetaminophen.

  10. Metallic nanoparticles deposited on carbon microspheres: novel materials for combinatorial electrochemistry and electroanalysis.

    Science.gov (United States)

    Baron, Ronan; Wildgoose, Gregory G; Compton, Richard G

    2009-04-01

    This review deals with the preparation of metallic nanoparticles on glassy carbon microspheres and the use of these new hybrid materials for combinatorial electrochemistry and electroanalysis. First, the preparation of gold, silver and palladium nanoparticles on glassy carbon microspheres by a simple electroless procedure is described. Then, different types of electrodes modified with glassy carbon microspheres are described. These are: (i) glassy carbon electrodes modified by a composite film of glassy carbon microspheres and multi-walled carbon nanotubes, (ii) basal plane pyrolylic graphite electrodes modified by the abrasive attachment of glassy carbon microspheres and (iii) carbon-epoxy composite electrodes loaded with glassy carbon microspheres. The three types of electrode architectures described consist of metallic nanoparticles embedded in a carbon matrix and each of the electrode macrodisc surfaces actually correspond to a random metallic nanoelectrode array. Carbon-epoxy composite electrodes have good characteristics for their use as practical sensors. Furthermore, the use of several kinds of metallic nanoparticles allows the construction of a multi-analyte electrode and the screening of electroactive materials by following a combinatorial approach.

  11. Direct Electrochemistry of Hemoglobin at a Graphene Gold Nanoparticle Composite Film for Nitric Oxide Biosensing

    Directory of Open Access Journals (Sweden)

    Guang-Chao Zhao

    2013-06-01

    Full Text Available A simple two-step method was employed for preparing nano-sized gold nanoparticles-graphene composite to construct a GNPs-GR-SDS modified electrode. Hemoglobin (Hb was successfully immobilized on the surface of a basal plane graphite (BPG electrode through a simple dropping technique. Direct electrochemistry and electrocatalysis of the hemoglobin-modified electrode was investigated. The as-prepared composites showed an obvious promotion of the direct electro-transfer between hemoglobin and the electrode. A couple of well-defined and quasi-reversible Hb CV peaks can be observed in a phosphate buffer solution (pH 7.0. The separation of anodic and cathodic peak potentials is 81 mV, indicating a fast electron transfer reaction. The experimental results also clarified that the immobilized Hb retained its biological activity for the catalysis toward NO. The biosensor showed high sensitivity and fast response upon the addition of NO, under the conditions of pH 7.0, potential ‒0.82 V. The time to reach the stable-state current was less than 3 s, and the linear response range of NO was 0.72–7.92 μM, with a correlation coefficient of 0.9991.

  12. Forensic electrochemistry: indirect electrochemical sensing of the components of the new psychoactive substance "Synthacaine".

    Science.gov (United States)

    Cumba, Loanda R; Kolliopoulos, Athanasios V; Smith, Jamie P; Thompson, Paul D; Evans, Peter R; Sutcliffe, Oliver B; do Carmo, Devaney R; Banks, Craig E

    2015-08-21

    "Synthacaine" is a New Psychoactive Substance which is, due to its inherent psychoactive properties, reported to imitate the effects of cocaine and is therefore consequently branded as "legal cocaine". The only analytical approach reported to date for the sensing of "Synthacaine" is mass spectrometry. In this paper, we explore and evaluate a range of potential analytical techniques for its quantification and potential use in the field screening "Synthacaine" using Raman spectroscopy, presumptive (colour) testing, High Performance Liquid Chromatography (HPLC) and electrochemistry. HPLC analysis of street samples reveals that "Synthacaine" comprises a mixture of methiopropamine (MPA) and 2-aminoindane (2-AI). Raman spectroscopy and presumptive (colour) tests, the Marquis, Mandelin, Simon's and Robadope test, are evaluated towards a potential in-the-field screening approach but are found to not be able to discriminate between the two when they are both present in the same sample, as is the case in the real street samples. We report for the first time a novel indirect electrochemical protocol for the sensing of MPA and 2-AI which is independently validated in street samples with HPLC. This novel electrochemical approach based upon one-shot disposable cost effective screen-printed graphite macroelectrodes holds potential for in-the-field screening for "Synthacaine".

  13. Applied superconductivity

    CERN Document Server

    Newhouse, Vernon L

    1975-01-01

    Applied Superconductivity, Volume II, is part of a two-volume series on applied superconductivity. The first volume dealt with electronic applications and radiation detection, and contains a chapter on liquid helium refrigeration. The present volume discusses magnets, electromechanical applications, accelerators, and microwave and rf devices. The book opens with a chapter on high-field superconducting magnets, covering applications and magnet design. Subsequent chapters discuss superconductive machinery such as superconductive bearings and motors; rf superconducting devices; and future prospec

  14. Direct Electrochemistry of Cytochrome C on the Glassy Carbon Electrode Modified with 1-Pyrenebutyric Acid/MWNTs

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    With 1-Pyrenebutyric acid (PBA) and multiwalled carbon nanotubes (MWNTs), glassy carbon electrode modified was successfully prepared. In phosphate buffer solution (pH 7.0), the direct electrochemistry of cytochrome C (Cyt C) was realized. In the cyclic voltammetry experiment two pairs of redox peaks of Cyt C were observed at 0.018 V and -0.314 V (vs. SCE),respectively. The redox reaction at 0.018 V was diffusion controlled, while the redox reaction at -0.314 V was adsorption controlled.

  15. Applied mathematics

    CERN Document Server

    Logan, J David

    2013-01-01

    Praise for the Third Edition"Future mathematicians, scientists, and engineers should find the book to be an excellent introductory text for coursework or self-study as well as worth its shelf space for reference." -MAA Reviews Applied Mathematics, Fourth Edition is a thoroughly updated and revised edition on the applications of modeling and analyzing natural, social, and technological processes. The book covers a wide range of key topics in mathematical methods and modeling and highlights the connections between mathematics and the applied and nat

  16. Applied Enzymology.

    Science.gov (United States)

    Manoharan, Asha; Dreisbach, Joseph H.

    1988-01-01

    Describes some examples of chemical and industrial applications of enzymes. Includes a background, a discussion of structure and reactivity, enzymes as therapeutic agents, enzyme replacement, enzymes used in diagnosis, industrial applications of enzymes, and immobilizing enzymes. Concludes that applied enzymology is an important factor in…

  17. Semiconductor electrochemistry of coal pyrite. Final technical report, September 1990--September 1995

    Energy Technology Data Exchange (ETDEWEB)

    Osseo-Asare, K.; Wei, Dawei

    1996-01-01

    This project seeks to advance the fundamental understanding of the physico-chemical processes occurring at the pyrite/aqueous interface, in the context of coal cleaning, coal desulfurization, and acid mine drainage. Central to this research is the use of synthetic microsize particles of pyrite as model microelectrodes to investigate the semiconductor electrochemistry of pyrite. The research focuses on: (a) the synthesis of microsize particles of pyrite in aqueous solution at room temperature, (b) the formation of iron sulfide complex, the precursor of FeS or FeS{sub 2}, and (c) the relationship between the semiconductor properties of pyrite and its interfacial electrochemical behavior in the dissolution process. In Chapter 2, 3 and 4, a suitable protocol for preparing microsize particles of pyrite in aqueous solution is given, and the essential roles of the precursors elemental sulfur and ``FeS`` in pyrite formation are investigated. In Chapter 5, the formation of iron sulfide complex prior to the precipitation of FeS or FeS{sub 2} is investigated using a fast kinetics technique based on a stopped-flow spectrophotometer. The stoichiometry of the iron sulfide complex is determined, and the rate and formation constants are also evaluated. Chapter 6 provides a summary of the semiconductor properties of pyrite relevant to the present study. In Chapters 7 and 8, the effects of the semiconductor properties on pyrite dissolution are investigated experimentally and the mechanism of pyrite dissolution in acidic aqueous solution is examined. Finally, a summary of the conclusions from this study and suggestions for future research are presented in Chapter 9.

  18. Recent Advances in Modeling Transition Metal Oxides for Photo-electrochemistry

    Science.gov (United States)

    Caspary Toroker, Maytal

    Computational research offers a wide range of opportunities for materials science and engineering, especially in the energy arena where there is a need for understanding how material composition and structure control energy conversion, and for designing materials that could improve conversion efficiency. Potential inexpensive materials for energy conversion devices are metal oxides. However, their conversion efficiency is limited by at least one of several factors: a too large band gap for efficiently absorbing solar energy, similar conduction and valence band edge characters that may lead to unfavorably high electron-hole recombination rates, a valence band edge that is not positioned well for oxidizing water, low stability, low electronic conductivity, and low surface reactivity. I will show how we model metal oxides with ab-initio methods, primarily DFT +U. Our previous results show that doping with lithium, sodium, or hydrogen could improve iron (II) oxide's electronic properties, and alloying with zinc or nickel could improve iron (II) oxide's optical properties. Furthermore, doping nickel (II) oxide with lithium could improve several key properties including solar energy absorption. In this talk I will highlight new results on our understanding of the mechanism of iron (III) oxide's surface reactivity. Our theoretical insights bring us a step closer towards understanding how to design better materials for photo-electrochemistry. References: 1. O. Neufeld and M. Caspary Toroker, ``Pt-doped Fe2O3 for enhanced water splitting efficiency: a DFT +U study'', J. Phys. Chem. C 119, 5836 (2015). 2. M. Caspary Toroker, ``Theoretical Insights into the Mechanism of Water Oxidation on Non-stoichiometric and Ti - doped Fe2O3 (0001)'', J. Phys. Chem. C, 118, 23162 (2014). This research was supported by the Morantz Energy Research Fund, the Nancy and Stephen Grand Technion Energy Program, the I-CORE Program of the Planning and Budgeting Committee, and The Israel Science

  19. Nanoplated bismuth titanate sub-microspheres for protein immobilization and their corresponding direct electrochemistry and electrocatalysis.

    Science.gov (United States)

    Chen, Xiaohua; Hu, Jianqiang; Chen, Zhiwu; Feng, Xiumei; Li, Aiqing

    2009-08-15

    A layered inorganic perovskite sub-micrometer-scale material, nanoplated bismuth titanate (Bi(4)Ti(3)O(12)) sub-microspheres (NBTSMs) constructed with tens of Bi(4)Ti(3)O(12) nanoplates, was for the first time synthesized by a facile hydrothermal synthesis strategy. The NBTSMs were employed as a supporting matrix to explore a novel immobilization and biosensing platform of redox proteins through a combined hydrogen bond and electrostatic assembly process. Biocompatibility, stability, reproducibility, and electrochemical and electrocatalytic properties of the resulting NBTSMs-based composite were studied by UV-vis absorption, FTIR, and electrochemical methods. The research results revealed that the NBTSMs-based composite was a satisfying matrix for proteins to effectively retain their native structure and bioactivity. With advantages of the Bi(4)Ti(3)O(12) layered material, facilitated direct electron transfer of the metalloenzymes with an apparent heterogeneous electron transfer rate constant (k(s)) of 20.0+/-3.8s(-1) was acquired on the NBTSMs-based enzyme electrode. The NBTSMs-based biosensor demonstrated significant electrocatalytic activity for the reduction of hydrogen peroxide with an apparent Michaelis-Menten constant (204 microM), wide linear range (2-430 microM), and low detection limit (0.46 microM, S/N=3). These indicated that the nanoplate-constructed Bi(4)Ti(3)O(12) sub-microspheres were one of ideal candidate materials for direct electrochemistry of redox proteins and the construction of the related enzyme biosensors, and may find potential applications in biomedical, food, and environmental analysis and detection.

  20. Direct electrochemistry and electrocatalysis of hemoglobin in graphene oxide and ionic liquid composite film

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei, E-mail: swyy26@hotmail.com [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Gong, Shixing [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Shi, Fan [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China); Cao, Lili; Ling, Luyang [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zheng, Weizhe; Wang, Wencheng [College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158 (China)

    2014-07-01

    In this paper a novel sensing platform based on graphene oxide (GO), ionic liquid (IL) 1-ethyl-3-methylimidazolium tetrafluoroborate and Nafion for the immobilization of hemoglobin (Hb) was adopted with a carbon ionic liquid electrode (CILE) as the substrate electrode, which was denoted as Nafion/Hb–GO–IL/CILE. Spectroscopic results suggested that Hb molecules were not denatured in the composite. A pair of well-defined redox peaks appeared on the cyclic voltammogram, which was attributed to the realization of direct electron transfer of Hb on the electrode. Electrochemical behaviors of Hb entrapped in the film were carefully investigated by cyclic voltammetry with the electrochemical parameters calculated. Based on the catalytic ability of the immobilized Hb, Nafion/Hb–GO–IL/CILE exhibited excellent electrocatalytic behavior towards the reduction of different substrates such as trichloroacetic acid in the concentration range from 0.01 to 40.0 mM with the detection limit as 3.12 μM (3σ), H{sub 2}O{sub 2} in the concentration range from 0.08 to 635.0 μM with the detection limit as 0.0137 μM (3σ) and NaNO{sub 2} in the concentration range from 0.5 to 800.0 μM with the detection limit as 0.0104 μM (3σ). So the proposed bioelectrode could be served as a new third-generation electrochemical sensor without mediator. - Highlights: • A graphene oxide, 1-ethyl-3-methylimidazolium tetrafluoroborate and hemoglobin composite were prepared. • Composite modified carbon ionic liquid electrode was fabricated. • Direct electrochemistry of hemoglobin was realized on the modified electrode. • Bioelectrocatalytic reduction of the modified electrode to different substrates was studied.

  1. Direct Electrochemistry of Redox Proteins and Enzymes Promoted by Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Chenxin Cai

    2005-04-01

    Full Text Available The redox protein and enzyme, such as hemoglobin (Hb, horseradish peroxidase(HRP and glucose oxidase (GOx, was immobilized on the surface of the carbon nanotubemodified glassy carbon (CNT/GC electrode, respectively. The cyclic voltammetric resultsindicated that the redox protein and enzyme underwent effective and stable direct electrontransfer reaction with a pair of nearly symmetrical redox peaks. The formal redox potential,E0’, was almost independent on the scan rates, the average value of E0’ for Hb, HRP andGOx was –0.343 ± 0.001, –0.319 ± 0.002 and –0.456 ± 0.0008 V (vs. SCE,pH 6.9,respectively. The dependence of E0’ on the pH solution indicated that the direct electrontransfer of Hb and HRP was a one-electron-transfer reaction process coupled with oneproton-transfer, while the GOx was a two-electron-transfer coupled with two-protontransfer.The apparent heterogeneous electron transfer rate constant (ks was 1.25 ± 0.25,2.07 ± 0.69 and 1.74 ± 0.42 s-1 for Hb, HRP and GOx, respectively. The method presentedhere can be easily extended to immobilize other redox enzymes or proteins and obtain theirdirect electrochemistry.

  2. Applied dynamics

    CERN Document Server

    Schiehlen, Werner

    2014-01-01

    Applied Dynamics is an important branch of engineering mechanics widely applied to mechanical and automotive engineering, aerospace and biomechanics as well as control engineering and mechatronics. The computational methods presented are based on common fundamentals. For this purpose analytical mechanics turns out to be very useful where D’Alembert’s principle in the Lagrangian formulation proves to be most efficient. The method of multibody systems, finite element systems and continuous systems are treated consistently. Thus, students get a much better understanding of dynamical phenomena, and engineers in design and development departments using computer codes may check the results more easily by choosing models of different complexity for vibration and stress analysis.

  3. The direct electrochemistry of glucose oxidase based on the synergic effect of amino acid ionic liquid and carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Amino acid ionic liquids(AAILs) have attracted much attention due to their special chemical and physical properties,especially their outstanding biocompatibility and truly green aspect.In this work,a novel electrochemical biosensing platform based on AAILs/carbon nanotubes(CNTs) composite was fabricated.AAILs were used as a novel solvent for glucose oxidase(GOD) and the GOD-AAILs/CNTs/GC electrode was conveniently prepared by immersing the carbon nanotubes(CNTs) modified glassy carbon(GC) electrode into AAILs containing GOD.The direct electrochemistry of GOD on the GOD-AAILs/CNTs/GC electrode has been investigated and a pair of reversible peaks was obtained by cyclic voltammetry.The immobilized glucose oxidase could retain bioactivity and catalyze the reduction of dissolved oxygen.Due to the synergic effect of AAILs and CNTs,the GOD-AAILs/CNTs/GC electrode shows excellent electrocatalytic activity towards glucose with a linear range from 0.05 to 0.8 mM and a detection limit of 5.5 μM(S/N = 3).Furthermore,the biosensor exhibits good stability and ability to exclude the interference of commonly coexisting uric and ascorbic acid.Therefore,AAILs/CNTs composite can be a good candidate biocompatible material for the direct electrochemistry of the redox-active enzyme and the construction of third-generation enzyme sensors.

  4. Conceptual Difficulties Experienced by Prospective Teachers in Electrochemistry: Half-Cell Potential, Cell Potential, and Chemical and Electrochemical Equilibrium in Galvanic Cells.

    Science.gov (United States)

    Ozkaya, Ali Riza

    2002-01-01

    A previous study of prospective teachers found that students from different countries and different levels of electrochemistry hold common misconceptions, indicating that concepts were presented to them poorly. Reports on how prospective teachers' scientifically incorrect ideas were used to form assertion-reason-type questions and how these…

  5. Li/Ag2VO2PO4 batteries: the roles of composite electrode constituents on electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Bock, David C.; Bruck, Andrea M.; Pelliccione, Christopher J.; Zhang, Yiman; Takeuchi, Kenneth J.; Marschilok, Amy C.; Takeuchi, Esther S. (BNL); (SBU)

    2016-11-01

    Silver vanadium phosphorous oxide, Ag2V2OPO4, was used as a model system to systematically study the impact on the constituents of a composite electrode, including polymeric and conductive additives, on electrochemistry. Three different electrode compositions were investigated.

  6. Roles of surface chemistry on safety and electrochemistry in lithium ion batteries.

    Science.gov (United States)

    Lee, Kyu Tae; Jeong, Sookyung; Cho, Jaephil

    2013-05-21

    Motivated by new applications including electric vehicles and the smart grid, interest in advanced lithium ion batteries has increased significantly over the past decade. Therefore, research in this field has intensified to produce safer devices with better electrochemical performance. Most research has focused on the development of new electrode materials through the optimization of bulk properties such as crystal structure, ionic diffusivity, and electric conductivity. More recently, researchers have also considered the surface properties of electrodes as critical factors for optimizing performance. In particular, the electrolyte decomposition at the electrode surface relates to both a lithium ion battery's electrochemical performance and safety. In this Account, we give an overview of the major developments in the area of surface chemistry for lithium ion batteries. These ideas will provide the basis for the design of advanced electrode materials. Initially, we present a brief background to lithium ion batteries such as major chemical components and reactions that occur in lithium ion batteries. Then, we highlight the role of surface chemistry in the safety of lithium ion batteries. We examine the thermal stability of cathode materials: For example, we discuss the oxygen generation from cathode materials and describe how cells can swell and heat up in response to specific conditions. We also demonstrate how coating the surfaces of electrodes can improve safety. The surface chemistry can also affect the electrochemistry of lithium ion batteries. The surface coating strategy improved the energy density and cycle performance for layered LiCoO2, xLi2MnO3·(1 - x)LiMO2 (M = Mn, Ni, Co, and their combinations), and LiMn2O4 spinel materials, and we describe a working mechanism for these enhancements. Although coating the surfaces of cathodes with inorganic materials such as metal oxides and phosphates improves the electrochemical performance and safety properties of

  7. Nickel-free manganese bearing stainless steel in alkaline media-Electrochemistry and surface chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, B., E-mail: belsener@unica.i [Dipartimento di Chimica Inorganica ed Analitica, Universita di Cagliari, SS 554 bivio per Sestu, I-09042 Monserrato (Italy); ETH Zurich, Institute for Building Materials, ETH Hoenggerberg, CH-8093 Zurich (Switzerland); Addari, D. [Dipartimento di Chimica Inorganica ed Analitica, Universita di Cagliari, SS 554 bivio per Sestu, I-09042 Monserrato (Italy); Coray, S. [ETH Zurich, Institute for Building Materials, ETH Hoenggerberg, CH-8093 Zurich (Switzerland); Rossi, A., E-mail: rossi@unica.i [Dipartimento di Chimica Inorganica ed Analitica, Universita di Cagliari, SS 554 bivio per Sestu, I-09042 Monserrato (Italy)

    2011-04-30

    Research highlights: {yields} New nickel-free manganese bearing 18Cr18Mn2Mo stainless steel in alkaline media. {yields} XPS analysis shows Mo(VI) enrichment up to 6% in the passive film upon ageing. {yields} No pitting corrosion in alkaline media (pH 13) up to 4 M NaCl (14 wt%). {yields} Promising alternative stainless steel for reinforcement in concrete. - Abstract: The use of austenitic nickel-containing stainless steels as concrete reinforcement offers excellent corrosion protection for concrete structures in harsh chloride bearing environments but is often limited due to the very high costs of these materials. Manganese bearing nickel-free stainless steels can be a cost-effective alternative for corrosion resistant reinforcements. Little, however, is known about the electrochemistry and even less on surface chemistry of these materials in alkaline media simulating concrete pore solutions. In this work a combined electrochemical (ocp = open circuit potential) and XPS (X-ray photoelectron spectroscopy) surface analytical investigation on the austenitic manganese bearing DIN 1.4456 (X8CrMnMoN18-18-2) stainless steel immersed into 0.1 M NaOH and more complex alkaline concrete pore solutions was performed. The results show that the passive film composition changes with immersion time, being progressively enriched in chromium oxy-hydroxide becoming similar to the conventional nickel-containing stainless steels. The composition of the metal interface beneath the passive film is strongly depleted in manganese and enriched in iron; chromium has nearly the nominal composition. The results are discussed regarding the film growth mechanism (ageing) of the new nickel-free stainless steel in alkaline solutions compared to traditional austenitic steels. Combining the results from pitting potential measurements with the composition of the passive film and the underlying metal interface, it can be concluded that the resistance against localized corrosion of the new nickel

  8. Applied combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    From the title, the reader is led to expect a broad practical treatise on combustion and combustion devices. Remarkably, for a book of modest dimension, the author is able to deliver. The text is organized into 12 Chapters, broadly treating three major areas: combustion fundamentals -- introduction (Ch. 1), thermodynamics (Ch. 2), fluid mechanics (Ch. 7), and kinetics (Ch. 8); fuels -- coal, municipal solid waste, and other solid fuels (Ch. 4), liquid (Ch. 5) and gaseous (Ch. 6) fuels; and combustion devices -- fuel cells (Ch. 3), boilers (Ch. 4), Otto (Ch. 10), diesel (Ch. 11), and Wankel (Ch. 10) engines and gas turbines (Ch. 12). Although each topic could warrant a complete text on its own, the author addresses each of these major themes with reasonable thoroughness. Also, the book is well documented with a bibliography, references, a good index, and many helpful tables and appendices. In short, Applied Combustion does admirably fulfill the author`s goal for a wide engineering science introduction to the general subject of combustion.

  9. A história, evolução e crescimento da Eletroquímica: Eletroanalítica nestes últimos 25 anos The history, evolution and growth of Electrochemistry: Electroanalytical chemistry in the past 25 years

    OpenAIRE

    Luis Alberto Avaca; Roberto Tokoro

    2002-01-01

    This text describes the development of Electrochemistry and Electroanalytical Chemistry in Brazil from the pioneers at the IQ/USP in the 70's to the present day status. It explains how the members of the scientific community organized themselves before the establishment in 1993 of a specific division within the Brazilian Chemical Society (SBQ) through bi-ennial meetings (Brazilian Symposium of Electrochemistry and Electroanalytical Chemistry - SIBEE). Those SIBEE meetings, in a present number...

  10. In situ STM imaging and direct electrochemistry of Pyrococcus furiosus ferredoxin assembled on thiolate-modified Au(111) surfaces

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Christensen, Hans Erik Mølager; Ooi, Bee Lean;

    2004-01-01

    We have addressed here electron transfer (ET) of Pyrococcus furiosus ferredoxin (PfFd, 7.5 kDa) in both homogeneous solution using edge plane graphite (EPG) electrodes and in the adsorbed state by electrochemistry on surface-modified single-crystal Au(111) electrodes, This has been supported...... with a formal potential of ca -430 mV (vs SCE), corresponding to [3Fe-4S](1+/0). The presence of an additional promoter, which can be propionic acid, alanine, or cysteine, induces a second pair of redox peaks at similar to-900 mV (vs SCE) arising from [3Fe-4S](0/1-). A robust neomycin-PfFd complex was detected...

  11. Electronic density functional theory in the grand canonical ensemble, electrochemistry, and the underpotential deposition of Cu/Pt(111)

    Science.gov (United States)

    Sundararaman, Ravishankar; Weaver, Kendra; Arias, Tomas

    2012-02-01

    The study of electrochemical systems within electronic density functional theory requires the handling of non-neutral electronic systems in the plane-wave basis in order to accurately describe charged metallic surfaces; this can be accomplished in joint density functional theory by adding an electrolyte with Debye screening ootnotetextK. L. Weaver and T. A. Arias (under preparation). This capability opens up the opportunity to work in the grand canonical ensemble at fixed chemical potential μ for the electrons, which corresponds directly to the experimental setting in electrochemistry. We present efficient techniques for electronic density functional calculations at fixed μ, and demonstrate the improvement in predictive power over conventional neutral calculations using the underpotential deposition of Cu/Pt(111) as an example: for the first time, we calculate absolute voltages for electrochemical processes in excellent agreement with experiment, instead of voltage shifts alone.

  12. Direct electrochemistry and electrocatalysis of heme-proteins immobilized in porous carbon nanofiber/room-temperature ionic liquid composite film

    Energy Technology Data Exchange (ETDEWEB)

    Sheng Qinglin [Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi' an, Shaanxi 710069 (China); Zheng Jianbin, E-mail: zhengjb@nwu.edu.c [Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi' an, Shaanxi 710069 (China); Shangguan Xiaodong [Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi' an, Shaanxi 710069 (China); Lin Wanghua; Li Yuanyao [Department of Chemical Engineering, National Chung Cheng University, Chia-Yi 62102, Taiwan (China); Liu Ruixiao [Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi' an, Shaanxi 710069 (China)

    2010-03-30

    The combination of porous carbon nanofiber (PCNF) and room-temperature ionic liquid (RTIL) provided a suitable microenvironment for heme-proteins to transfer electron directly. Hemoglobin, myoglobin, and cytochrome c incorporated in PCNF/RTIL films exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks at about -0.28 V vs. SCE in pH 7.0 buffers, respectively, characteristic of the protein heme Fe(III)/Fe(II) redox couples. The cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the modified electrode. The heme/PCNF/RTIL/CHIT films were also characterized by UV-vis spectroscopy, indicating that heme-proteins in the composite film could retain its native structure. Oxygen, hydrogen peroxide, and nitrite were catalytically reduced at the heme/PCNF/RTIL/CHIT film modified electrodes, showing the potential applicability of the films as the new type of biosensors or bioreactors based on direct electrochemistry of the redox proteins.

  13. Application of Carbon-Microsphere-Modified Electrodes for Electrochemistry of Hemoglobin and Electrocatalytic Sensing of Trichloroacetic Acid

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Wang

    2015-12-01

    Full Text Available By using the hydrothermal method, carbon microspheres (CMS were fabricated and used for electrode modification. The characteristics of CMS were investigated using various techniques. The biocompatible sensing platform was built by immobilizing hemoglobin (Hb on the micrometer-sized CMS-modified electrode with a layer of chitosan membrane. On the cyclic voltammogram, a couple of quasi-reversible cathodic and anodic peaks appeared, showing that direct electrochemistry of Hb with the working electrode was achieved. The catalytic reduction peak currents of the bioelectrode to trichloroacetic acid was established in the linear range of 2.0~70.0 mmol·L−1 accompanied by a detection limit of 0.30 mmol·L−1 (3σ. The modified electrode displayed favorable sensitivity, good reproducibility and stability, which suggests that CMS is promising for fabricating third-generation bioelectrochemical sensors.

  14. Fast single run of vanilla fingerprint markers on microfluidic-electrochemistry chip for confirmation of common frauds.

    Science.gov (United States)

    Avila, Mónica; Zougagh, Mohammed; Escarpa, Alberto; Ríos, Angel

    2009-10-01

    A new strategy based on the fast separation of the fingerprint markers of Vanilla planifolia extracts and vanilla-related samples on microfluidic-electrochemistry chip is proposed. This methodology allowed the detection of all required markers for confirmation of common frauds in this field. The elution order was strategically connected with sequential sample screening and analyte confirmation steps, where first ethyl vanillin was detected to distinguish natural from adultered samples; second, vanillin as prominent marker in V. planifolia, but frequently added in its synthetic form; and third, the final detection of the fingerprint markers (p-hydroxybenzaldehyde, vanillic acid, and p-hydroxybenzoic acid) of V. planifolia with confirmation purposes. The reliability of the proposed methodology was demonstrated in the confirmation the natural or non-natural origin of vanilla in samples using V. planifolia extracts and other selected food samples containing this flavor.

  15. In situ solid-state electrochemistry of mass-selected ions at well-defined electrode–electrolyte interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Venkateshkumar; Johnson, Grant E.; Wang, Bingbing; Laskin, Julia

    2016-11-07

    Molecular-level understanding of electrochemical processes occurring at electrode-electrolyte interfaces (EEI) is key to the rational development of high-performance and sustainable electrochemical technologies. This article reports the development and first application of solid-state in situ electrochemical probes to study redox and catalytic processes occurring at well-defined EEI generated using soft-landing of mass- and charge-selected cluster ions (SL). In situ electrochemical probes with excellent mass transfer properties are fabricated using carefully-designed nanoporous ionic liquid membranes. SL enables deposition of pure active species that are not obtainable with other techniques onto electrode surfaces with precise control over charge state, composition, and kinetic energy. SL is, therefore, a unique tool for studying fundamental processes occurring at EEI. For the first time using an aprotic electrochemical probe, the effect of charge state (PMo12O403-/2-) and the contribution of building blocks of Keggin polyoxometalate (POM) clusters to redox processes are characterized by populating EEI with novel POM anions generated by electrospray ionization and gas phase dissociation. Additionally, a proton conducting electrochemical probe has been developed to characterize the reactive electrochemistry (oxygen reduction activity) of bare Pt clusters (Pt40 ~1 nm diameter), thus demonstrating the capability of the probe for studying reactions in controlled gaseous environments. The newly developed in situ electrochemical probes combined with ion SL provide a versatile method to characterize the EEI in solid-state redox systems and reactive electrochemistry at precisely-defined conditions. This capability will advance molecular-level understanding of processes occurring at EEI that are critical to many energy-related technologies.

  16. Guiding Principles of Hydrogenase Catalysis Instigated and Clarified by Protein Film Electrochemistry.

    Science.gov (United States)

    Armstrong, Fraser A; Evans, Rhiannon M; Hexter, Suzannah V; Murphy, Bonnie J; Roessler, Maxie M; Wulff, Philip

    2016-05-17

    Protein film electrochemistry (PFE) is providing cutting-edge insight into the chemical principles underpinning biological hydrogen. Attached to an electrode, many enzymes exhibit "reversible" electrocatalytic behavior, meaning that a catalyzed redox reaction appears reversible or quasi-reversible when viewed by cyclic voltammetry. This efficiency is most relevant for enzymes that are inspiring advances in renewable energy, such as hydrogen-activating and CO2-reducing enzymes. Exploiting the rich repertoire of available instrumental methods, PFE experiments yield both a general snapshot and fine detail, all from tiny samples of enzyme. The dynamic electrochemical investigations blaze new trails and add exquisite detail to the information gained from structural and spectroscopic studies. This Account describes recent investigations of hydrogenases carried out in Oxford, including ideas initiated with PFE and followed through with complementary techniques, all contributing to an eventual complete picture of fast and efficient H2 activation without Pt. By immobilization of an enzyme on an electrode, catalytic electron flow and the chemistry controlling it can be addressed at the touch of a button. The buried nature of the active site means that structures that have been determined by crystallography or spectroscopy are likely to be protected, retained, and fully relevant in a PFE experiment. An electrocatalysis model formulated for the PFE of immobilized enzymes predicts interesting behavior and gives insight into why some hydrogenases are H2 producers and others are H2 oxidizers. Immobilization also allows for easy addition and removal of inhibitors along with precise potential control, one interesting outcome being that formaldehyde forms a reversible complex with reduced [FeFe]-hydrogenases, thereby providing insight into the order of electron and proton transfers. Experiments on O2-tolerant [NiFe]-hydrogenases show that O2 behaves like a reversible inhibitor: it

  17. Methodological evaluation of electrochemistry luminescent technique for HE4 detection%人附睾蛋白4检测试剂方法学评价

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      目的通过对罗氏公司电化学发光法检测人附睾蛋白4(human epididymal protein 4,HE4)试剂的方法学评价。方法检测本方法的批内变异系数和批间变异系数、线性实验。比较本方法与酶联免疫法检测结果的相关性分析,评估此方法的可靠性。结果在检测范围内,该方法的线性良好,检测的批内变异系数分别为1.05%和1.83%,批间变异系数分别为2.63%和2.68%,与酶联免疫法试剂检测结果比较呈良好相关性(R2=0.9966)。结论本方法测定结果准确可靠,操作简便,值得推广使用。%Objective To evaluate the detection methodology of HE4 using electrochemistry luminescent technique (Roche Company). Methods The variation coefficients for within runs and between runs and linear experiment were detected with electrochemistry luminescent technique, and compared with those detected by ELASA. The reliability of electrochemistry luminescent technique was assessed. Results The electrochemistry luminescent technique had a good linearity in the detection range. The variation coefficient for within runs and between runs was 1.05 and 1.83, and 2.63%and 2.68%, respectively, which were well correlated with those detected by ELISA (R2=0.9966). Conclusion The electrochemistry luminescent technique is accurate, reliable, and easy to operate, and is thus worthy to be widely used in clinical practice.

  18. Forensic electrochemistry applied to the sensing of new psychoactive substances: electroanalytical sensing of synthetic cathinones and analytical validation in the quantification of seized street samples.

    Science.gov (United States)

    Smith, Jamie P; Metters, Jonathan P; Khreit, Osama I G; Sutcliffe, Oliver B; Banks, Craig E

    2014-10-07

    The electrochemical sensing of new psychoactive substance(s) (NPSs), synthetic cathinone derivatives also termed "legal highs", are explored with the use of metallic modified screen-printed electrochemical sensors (SPES). It is found that no significant electrochemical enhancement is evident with the use of either in situ bismuth or mercury film modified SPES compared to the bare underlying electrode substrate. In fact, the direct electrochemical reduction of the cathinone derivatives mephedrone (4-methylmethcathinone; 4-MMC) and 4'-methyl-N-ethylcathinone (4-methylethcathinone; 4-MEC) is found to be possible for the first time, without heavy metal catalysis, giving rise to useful voltammetric electroanalytical signatures in model aqueous buffer solutions. This novel electroanalytical methodology is validated toward the determination of cathinone derivatives (4-MMC and 4-MEC) in three seized street samples that are independently analyzed with high-performance liquid chromatography (HPLC) wherein excellent agreement between the two analytical protocols is found. Such an approach provides a validated laboratory tool for the quantification of synthetic cathinone derivatives and holds potential for the basis of a portable analytical sensor for the determination of synthetic cathinone derivatives in seized street samples.

  19. Electrochemistry and determination of epinephrine using a mesoporous Al-incorporated SiO{sub 2} modified electrode

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yanhong; Yang, Jinquan; Wu, Kangbing [Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2008-05-30

    The potential application of Al-incorporated mesoporous SiO{sub 2} (denoted as Al-MCM-41) in electrochemistry as a novel electrode material was investigated. The peak currents of K{sub 3}[Fe(CN){sub 6}] remarkably increase and the peak potential separation obviously decreases at the mesoporous Al-MCM-41 modified carbon paste electrode (CPE). These phenomena suggest that the mesoporous Al-MCM-41 modified CPE possesses larger electrode area and electron transfer rate constant. Furthermore, the electrochemical behavior of epinephrine (EP) was investigated in different supporting electrolytes such as 0.01 mol L{sup -1} HClO{sub 4} and pH 7.0 phosphate buffer. It is found that the mesoporous Al-MCM-41 modified CPE exhibits catalytic ability to the oxidation of EP due to remarkable peak current enhancement and negative shift of peak potential. The electrochemical oxidation mechanism was also discussed. Finally, a novel electrochemical method was proposed for the determination of EP, which used to determine EP in urine samples. (author)

  20. Electrochemistry and determination of epinephrine using a mesoporous Al-incorporated SiO{sub 2} modified electrode

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Yanhong; Yang Jinquan [Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074 (China); Wu Kangbing [Department of Chemistry, Huazhong University of Science and Technology, Wuhan 430074 (China)], E-mail: kbwu@mail.hust.edu.cn

    2008-05-30

    The potential application of Al-incorporated mesoporous SiO{sub 2} (denoted as Al-MCM-41) in electrochemistry as a novel electrode material was investigated. The peak currents of K{sub 3}[Fe(CN){sub 6}] remarkably increase and the peak potential separation obviously decreases at the mesoporous Al-MCM-41 modified carbon paste electrode (CPE). These phenomena suggest that the mesoporous Al-MCM-41 modified CPE possesses larger electrode area and electron transfer rate constant. Furthermore, the electrochemical behavior of epinephrine (EP) was investigated in different supporting electrolytes such as 0.01 mol L{sup -1} HClO{sub 4} and pH 7.0 phosphate buffer. It is found that the mesoporous Al-MCM-41 modified CPE exhibits catalytic ability to the oxidation of EP due to remarkable peak current enhancement and negative shift of peak potential. The electrochemical oxidation mechanism was also discussed. Finally, a novel electrochemical method was proposed for the determination of EP, which used to determine EP in urine samples.

  1. Lack of nano size effect on electrochemistry of dopamine at a gold nanoparticle modified indium tin oxide electrode

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Nanometer sized materials have been shown to possess excellent chemical and electrochemical catalytic properties.In this work,a gold nanoparticle (AuNP) modified indium tin oxide (ITO) electrode was employed for investigating its electro-catalytic property.AuNP was deposited on the 3-aminopropyltriethoxysilane (APTES) modified ITO electrode by self-assembly,and was characterized by scanning electron microscopy and cyclic voltammetry.Although the electrochemical reaction of dopamine was very sluggish on the ITO/APTES electrode,it was significantly enhanced after AuNP deposition.The cyclic voltammogram exhibited apparent dependence on the surface coverage of 11 nm AuNPs,which could be rationalized by different modes of mass diffusion.Among the different sizes of AuNP investigated,the lowest anodic peak potential was observed on 11 nm AuNP.However,the potential was still about 50 mV more positive than that obtained on a bulk gold electrode of similar geometry.It is therefore concluded that there is no nanometer size effect of AuNP modified ITO on the electrochemistry of dopamine.

  2. Direct electrochemistry of horseradish peroxidase on Nafion/[bmim]PF(6)/agarose composite film modified glassy carbon electrode.

    Science.gov (United States)

    Fan, Da-He; Sun, Jun-Yong; Huang, Ke-Jing

    2010-03-01

    A new strategy to construct electrochemical biosensor for direct electrochemistry of horseradish peroxidase (HRP) on glassy carbon electrode (GCE) based on Nafion, agarose hydrogel and hydrophobic room-temperature ionic liquid (RTIL) 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF(6)) composite as sensing platform has been described. [bmim]PF(6) has good conductivity and wide electrochemical windows and agarose can maintain biological activity well. Nafion/[bmim]PF(6)/agarose composite combines the advantages of [bmim]PF(6) and agarose. Electrochemical impedance spectroscopy (EIS), ultraviolet visible spectroscopy (UV-vis), fourier transform infrared (FT-IR) spectroscopy and cyclic voltammetry (CV) were used to characterize the composite film, showing that the composite film could be effectively constructed on the GCE surface and greatly enhance the electron transfer between HRP and electrode. The factors influencing the performance of the resulting biosensor were studied in detail. The biosensor responded to H(2)O(2) in the linear range from 2x10(-6) to 1.6x10(-4)M with a detection limit of 1.2x10(-7)M (based on the S/N=3). The studied biosensor exhibited good accuracy and high sensitivity. Moreover, the proposed method was economical and efficient.

  3. Effect of alpha-cyclodextrin on drug distribution studied by electrochemistry at interfaces between immiscible electrolyte solutions.

    Science.gov (United States)

    Deryabina, Maria A; Hansen, Steen H; Østergaard, Jesper; Jensen, Henrik

    2009-05-21

    The description and understanding of noncovalent interactions and distribution of potential new drug compounds in an organism is of paramount importance for the successful development of new drugs. In this work, a new procedure based on electrochemistry at the interface between two immiscible electrolyte solutions (ITIES) for addressing and discriminating between drug compound/ligand interactions in aqueous solution and nonspecific ligand effects on oil-water distribution behavior has been developed. The procedure is demonstrated using five drug compounds with different physical chemical parameters and alpha-cyclodextrin as the aqueous phase ligand. Alpha-cyclodextrin was chosen as an aqueous phase ligand, as it is frequently used in drug formulations to enhance solubility and bioavailability of drug compounds. Supplementary capillary electrophoresis experiments provided more detailed information on alpha-cyclodextrin drug complexation and, in combination with the electrochemical studies, provided information on solvation effects affecting the oil-water distribution of the drug compounds. The use of ligand shift ion partition diagrams for data presentation is a convenient format for the visualization of ligand effects on distribution behavior of related drug compounds.

  4. Direct electrochemistry and electrocatalysis of horseradish peroxidase with hyaluronic acid-ionic liquid-cadmium sulfide nanorod composite material

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Zhihong [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Li Xia; Wang Yan [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Zeng Yan [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China); Sun Wei, E-mail: sunwei@qust.edu.cn [College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Huang Xintang [Institute of Nano-Science and Technology Center, Huazhong Normal University, Wuhan 430079 (China)

    2010-06-18

    A new composite material consisted of hyaluronic acid (HA), ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF{sub 4}) and cadmium sulfide (CdS) nanorod was fabricated and used for the immobilization of horseradish peroxidase (HRP) on the surface of a carbon ionic liquid electrode (CILE), which was prepared with 1-ethyl-3-methyl-imidazolium ethylsulphate ([EMIM]EtOSO{sub 3}) as modifier. Spectroscopic results indicated that HRP remained its native structure in the composite film. Based on the synergistic effect of the materials used, an obvious promotion to the direct electron transfer efficient between HRP and CILE was achieved with a pair of well-defined redox peaks appeared in 0.1 mol L{sup -1} phosphate buffer solution, indicating the realization of the direct electrochemistry of HRP. The immobilized HRP showed good electrocatalytic activity towards the reduction of trichloroacetic acid and H{sub 2}O{sub 2} with the electrochemical parameters calculated. Based on the fabricated electrode, a new third-generation electrochemical biosensor was constructed with good stability and reproducibility.

  5. Direct electrochemistry of cytochrome c immobilized on titanium nitride/multi-walled carbon nanotube composite for amperometric nitrite biosensor.

    Science.gov (United States)

    Haldorai, Yuvaraj; Hwang, Seung-Kyu; Gopalan, Anantha-Iyengar; Huh, Yun Suk; Han, Young-Kyu; Voit, Walter; Sai-Anand, Gopalan; Lee, Kwang-Pill

    2016-05-15

    In this report, titanium nitride (TiN) nanoparticles decorated multi-walled carbon nanotube (MWCNTs) nanocomposite is fabricated via a two-step process. These two steps involve the decoration of titanium dioxide nanoparticles onto the MWCNTs surface and a subsequent thermal nitridation. Transmission electron microscopy shows that TiN nanoparticles with a mean diameter of ≤ 20 nm are homogeneously dispersed onto the MWCNTs surface. Direct electrochemistry and electrocatalysis of cytochrome c immobilized on the MWCNTs-TiN composite modified on a glassy carbon electrode for nitrite sensing are investigated. Under optimum conditions, the current response is linear to its concentration from 1 µM to 2000 µM with a sensitivity of 121.5 µA µM(-1)cm(-2) and a low detection limit of 0.0014 µM. The proposed electrode shows good reproducibility and long-term stability. The applicability of the as-prepared biosensor is validated by the successful detection of nitrite in tap and sea water samples.

  6. Electrochemistry at nanoscale electrodes: individual single-walled carbon nanotubes (SWNTs) and SWNT-templated metal nanowires.

    Science.gov (United States)

    Dudin, Petr V; Snowden, Michael E; Macpherson, Julie V; Unwin, Patrick R

    2011-12-27

    Individual nanowires (NWs) and native single-walled carbon nanotubes (SWNTs) can be readily used as well-defined nanoscale electrodes (NSEs) for voltammetric analysis. Here, the simple photolithography-free fabrication of submillimeter long Au, Pt, and Pd NWs, with sub-100 nm heights, by templated electrodeposition onto ultralong flow-aligned SWNTs is demonstrated. Both individual Au NWs and SWNTs are employed as NSEs for electron-transfer (ET) kinetic quantification, using cyclic voltammetry (CV), in conjunction with a microcapillary-based electrochemical method. A small capillary with internal diameter in the range 30-70 μm, filled with solution containing a redox-active mediator (FcTMA(+) ((trimethylammonium)methylferrocene), Fe(CN)(6)(4-), or hydrazine) is positioned above the NSE, so that the solution meniscus completes an electrochemical cell. A 3D finite-element model, faithfully reproducing the experimental geometry, is used to both analyze the experimental CVs and derive the rate of heterogeneous ET, using Butler-Volmer kinetics. For a 70 nm height Au NW, intrinsic rate constants, k(0), up to ca. 1 cm s(-1) can be resolved. Using the same experimental configuration the electrochemistry of individual SWNTs can also be accessed. For FcTMA(+/2+) electrolysis the simulated ET kinetic parameters yield very fast ET kinetics (k(0) > 2 ± 1 cm s(-1)). Some deviation between the experimental voltammetry and the idealized model is noted, suggesting that double-layer effects may influence ET at the nanoscale.

  7. Surface analysis and electrochemistry of a robust carbon-nanofiber-based electrode platform H2O2 sensor

    Science.gov (United States)

    Suazo-Dávila, D.; Rivera-Meléndez, J.; Koehne, J.; Meyyappan, M.; Cabrera, C. R.

    2016-10-01

    A vertically aligned carbon nanofiber-based (VACNF) electrode platform was developed for an enzymeless hydrogen peroxide sensor. Vertical nanofibers have heights on the order of 2-3 μm, and diameters that vary from 50 to 100 nm as seen by atomic force microscopy. The VACNF was grown as individual, vertically, and freestanding structures using plasma-enhanced chemical vapor deposition. The electrochemical sensor, for the hydrogen peroxide measurement in solution, showed stability and reproducibility in five consecutive calibration curves with different hydrogen peroxide concentrations over a period of 3 days. The detection limit was 66 μM. The sensitivity for hydrogen peroxide electrochemical detection was 0.0906 mA cm-2 mM-1, respectively. The sensor was also used for the measurement of hydrogen peroxide as the by-product of the reaction of cholesterol with cholesterol oxidase as a biosensor application. The sensor exhibits linear behavior in the range of 50 μM-1 mM in cholesterol concentrations. The surface analysis and electrochemistry characterization is presented.

  8. From mercury to nanosensors: Past, present and the future perspective of electrochemistry in pharmaceutical and biomedical analysis.

    Science.gov (United States)

    Ozkan, Sibel A; Uslu, Bengi

    2016-10-25

    Polarography was the first developed automated method of voltage-controlled electrolysis with dropping mercury electrode (DME). Then, hanging mercury drop and static mercury drop electrodes were added as an alternative indicator electrode. In this way, polarography turned formally into voltammetry with mercury electrodes in the electroreduction way. Solid electrodes such as noble metal and carbon based electrodes can be used for the investigation of the compounds for both oxidation and reduction directions, which is called voltammetry. The voltammetric and polarographic techniques are more sensitive, reproducible, and easily used electroanalytical methods that can be alternative to more frequently used separation and spectrometric methods. Furthermore, in some cases there is a relationship between voltammetry and pharmaceutical samples, and the knowledge of the mechanism of their electrode reactions can give a useful clue in elucidation of the mechanism of their interaction with living cells. The voltammetric and polarographic analysis of drugs in pharmaceutical preparations are by far the most common use of electrochemistry for analytical pharmaceutical problems. Recent trends and challenges in the electrochemical methods for the detection of DNA hybridization and pathogens are available. Low cost, small sample requirement and possibility of miniaturization justifies their increasing development.

  9. Direct electrochemistry of catalase at amine-functionalized graphene/gold nanoparticles composite film for hydrogen peroxide sensor

    Energy Technology Data Exchange (ETDEWEB)

    Huang Kejing, E-mail: kejinghuang@163.co [College of Chemistry and Chemical Engineering, Xinyang Normal University, 237 Chang' an Road, Xinyang, He' nan 464000 (China); Niu Dejun; Liu Xue; Wu Zhiwei; Fan Yang; Chang Yafang; Wu Yingying [College of Chemistry and Chemical Engineering, Xinyang Normal University, 237 Chang' an Road, Xinyang, He' nan 464000 (China)

    2011-02-28

    Direct electrochemistry and electrocatalysis of catalase (Cat) was studied based on a nano-composite film consisting of amine functionalized graphene and gold nanoparticles (AuNPs) modified glassy carbon electrode. Graphene was synthesized chemically by Hummers and Offeman method and then was functionalized with amino groups via chemical modification of carboxyl groups introduced on the graphene surface. The nano-composite film showed an obvious promotion of the direct electron transfer between Cat and the underlying electrode, which attributed to the synergistic effect of graphene-NH{sub 2} and AuNPs. The resultant bioelectrode retained its biocatalytic activity and offered fast and sensitive H{sub 2}O{sub 2} quantification. Under the optimized experimental conditions, hydrogen peroxide was detected in the concentration range from 0.3 to 600 {mu}M with a detection limit of 50 nM at S/N = 3. The biosensor exhibited some advantages, such as short time respond (2 s), high sensitivity (13.4 {mu}A/mM) and good reproducibility (RSD = 5.8%).

  10. A história, evolução e crescimento da Eletroquímica: Eletroanalítica nestes últimos 25 anos The history, evolution and growth of Electrochemistry: Electroanalytical chemistry in the past 25 years

    Directory of Open Access Journals (Sweden)

    Luis Alberto Avaca

    2002-05-01

    Full Text Available This text describes the development of Electrochemistry and Electroanalytical Chemistry in Brazil from the pioneers at the IQ/USP in the 70's to the present day status. It explains how the members of the scientific community organized themselves before the establishment in 1993 of a specific division within the Brazilian Chemical Society (SBQ through bi-ennial meetings (Brazilian Symposium of Electrochemistry and Electroanalytical Chemistry - SIBEE. Those SIBEE meetings, in a present number of 12, are described individually giving some emphasis on their organizers, the invited speakers and the statistics and overall structure of the event. The activities of the Electrochemistry and Electroanalytical Chemistry Division of the SBQ from 1993 are also briefly discussed as well as some considerations are made on the present and future of these fields.

  11. Synthesis, photophysics, electrochemistry, thermal stability and electroluminescent performances of a new europium complex with bis(β-diketone) ligand containing carbazole group.

    Science.gov (United States)

    Liu, Jian; Liang, Quan-Bin; Wu, Hong-Bin

    2016-09-07

    We synthesized a new europium complex [Eu(ecbpd)3 (Phen)] with bis(β-diketone) ligand containing a carbazole group, in which ecbpd and Phen are dehydro-3,3'-(9-ethyl-9H-carbazole-3,6-diyl)bis(1-phenylpropane-1,3-dione) and 1,10-phenanthroline, respectively. Its UV/vis and photoluminescent spectra, quantum yield, luminescence lifetime, electrochemistry, thermal stability and electroluminescent performances were studied. This europium complex showed low efficiency luminescence, which is probably due to the mismatching energy levels of its ligand and Eu(3)(+) , as well as the double Eu(3)(+) core resonance.

  12. Fully solar-driven thermo- and electrochemistry for advanced oxidation processes (STEP-AOPs) of 2-nitrophenol wastewater.

    Science.gov (United States)

    Nie, Chunhong; Shao, Nan; Wang, Baohui; Yuan, Dandan; Sui, Xin; Wu, Hongjun

    2016-07-01

    The STEP (Solar Thermal Electrochemical Process) for Advanced Oxidation Processes (AOPs, combined to STEP-AOPs), fully driven by solar energy without the input of any other forms of energy and chemicals, is introduced and demonstrated from the theory to experiments. Exemplified by the persistent organic pollutant 2-nitrophenol in water, the fundamental model and practical system are exhibited for the STEP-AOPs to efficiently transform 2-nitrophenol into carbon dioxide, water, and the other substances. The results show that the STEP-AOPs system performs more effectively than classical AOPs in terms of the thermodynamics and kinetics of pollutant oxidation. Due to the combination of solar thermochemical reactions with electrochemistry, the STEP-AOPs system allows the requisite electrolysis voltage of 2-nitrophenol to be experimentally decreased from 1.00 V to 0.84 V, and the response current increases from 18 mA to 40 mA. STEP-AOPs also greatly improve the kinetics of the oxidation at 30 °C and 80 °C. As a result, the removal rate of 2-nitrophenol after 1 h increased from 19.50% at 30 °C to 32.70% at 80 °C at constant 1.90 V. Mechanistic analysis reveals that the oxidation pathway is favorably changed because of thermal effects. The tracking of the reaction displayed that benzenediol and hydroquinone are initial products, with maleic acid and formic acid as sequential carboxylic acid products, and carbon dioxide as the final product. The theory and experiments on STEP-AOPs system exemplified by the oxidation of 2-nitrophenol provide a broad basis for extension of the STEP and AOPs for rapid and efficient treatment of organic wastewater.

  13. In situ solid-state electrochemistry of mass-selected ions at well-defined electrode-electrolyte interfaces.

    Science.gov (United States)

    Prabhakaran, Venkateshkumar; Johnson, Grant E; Wang, Bingbing; Laskin, Julia

    2016-11-22

    Molecular-level understanding of electrochemical processes occurring at electrode-electrolyte interfaces (EEIs) is key to the rational development of high-performance and sustainable electrochemical technologies. This article reports the development and application of solid-state in situ thin-film electrochemical cells to explore redox and catalytic processes occurring at well-defined EEIs generated using soft-landing (SL) of mass- and charge-selected cluster ions. In situ cells with excellent mass-transfer properties are fabricated using carefully designed nanoporous ionic liquid membranes. SL enables deposition of pure active species that are not obtainable with other techniques onto electrode surfaces with precise control over charge state, composition, and kinetic energy. SL is, therefore, demonstrated to be a unique tool for studying fundamental processes occurring at EEIs. Using an aprotic cell, the effect of charge state ([Formula: see text]) and the contribution of building blocks of Keggin polyoxometalate (POM) clusters to redox processes are characterized by populating EEIs with POM anions generated by electrospray ionization and gas-phase dissociation. Additionally, a proton-conducting cell has been developed to characterize the oxygen reduction activity of bare Pt clusters (Pt30 ∼1 nm diameter), thus demonstrating the capability of the cell for probing catalytic reactions in controlled gaseous environments. By combining the developed in situ electrochemical cell with ion SL we established a versatile method to characterize the EEI in solid-state redox systems and reactive electrochemistry at precisely defined conditions. This capability will advance the molecular-level understanding of processes occurring at EEIs that are critical to many energy-related technologies.

  14. CHANGES IN CORTICAL KYNURENIC ACID BI-DIRECTIONALLY MODULATE PREFRONTAL GLUTAMATE LEVELS AS ASSESSED BY MICRODIALYSIS AND RAPID ELECTROCHEMISTRY

    Science.gov (United States)

    Konradsson-Geuken, Ȧ.; Gash, C. R.; Wu, H.-Q.; Alexander, K. S.; Pellicciari, R.; Schwarcz, R.; Bruno, J.P.

    2010-01-01

    Using two in vivo methods, microdialysis and rapid in situ electrochemistry, this study examined the modulation of extracellular glutamate levels by endogenously produced kynurenic acid (KYNA) in the prefrontal cortex (PFC) of awake rats. Measured by microdialysis, intraperitoneal (i.p.) administration of KYNA's bioprecursor L-kynurenine dose-dependently elevated extracellular KYNA and reduced extracellular glutamate (nadir after 50 mg/kg kynurenine: 60% decrease from baseline values). This dose-dependent decrease in glutamate levels was also seen using a glutamate-sensitive microelectrode array (MEA) (31% decrease following 50 mg/kg kynurenine). The kynurenine-induced reduction in glutamate was blocked (microdialysis) or attenuated (MEA) by co-administration of galantamine (3 mg/kg, i.p.), a drug that competes with KYNA at an allosteric potentiating site of the α7 nicotinic acetylcholine receptor. In separate experiments, extracellular glutamate levels were measured by MEA following the local perfusion (45 min) of the PFC with kynurenine (2.5 μM) or the selective KYNA biosynthesis inhibitor S-ethylsulfonylbenzoylalanine (S-ESBA; 5 mM). In agreement with previous microdialysis studies, systemic kynurenine application produced a reversible reduction in glutamate (nadir: −29%), whereas perfusion with S-ESBA increased glutamate levels reversibly (maximum: +38%). Collectively, these results demonstrate that fluctuations in the biosynthesis of KYNA in the PFC bi-directionally modulate extracellular glutamate levels, and that qualitatively very similar data are obtained by microdialysis and MEA. Since KYNA levels are elevated in the PFC of individuals with schizophrenia, and since prefrontal glutamatergic and nicotinic transmission mediate cognitive flexibility, normalization of KYNA levels in the PFC may constitute an effective treatment strategy for alleviating cognitive deficits in schizophrenia. PMID:20600676

  15. Fullerene-nitrogen doped carbon nanotubes for the direct electrochemistry of hemoglobin and its application in biosensing.

    Science.gov (United States)

    Sheng, Qinglin; Liu, Ruixiao; Zheng, Jianbin

    2013-12-01

    The direct electrochemistry of hemoglobin (Hb) immobilized by a fullerene-nitrogen doped carbon nanotubes and chitosan (C60-NCNTs/CHIT) composite matrix is demonstrated. The cyclic voltammetry and electrochemical impedance spectroscopy were used to characterize the modified electrode. In the deaerated buffer solution, the cyclic voltammogram of the Hb/C60-NCNTs/CHIT composite film modified electrode showed a pair of well-behaved redox peaks with the E°'=-0.335 (± 0.3) V (vs. SCE). The redox peaks are assigned to the redox reaction of Hb(Fe(III)/Fe(II)) and confirm the effective immobilization of Hb on the composite film. The large value of ks = 1.8 (± 0.2)s(-1) suggests that the immobilized Hb achieved a relative fast electron transfer process. The fast electron transfer interaction between protein and electrode surface suggested that the C60-NCNTs/CHIT composite film may mimic some physiological process and further elucidate the relationship between protein structures and biological functions. Moreover, the resulting electrode exhibited excellent electrocatalytic ability towards the reduction of hydrogen peroxide (H2O2) with the linear dynamic range of 2.0-225.0 μM. The linear regression equation was Ip/μA=7.35 (± 0.08)+0.438 (± 0.007)C/μM with the correlation coefficient of 0.9993. The detection limit was estimated at about 1 μM (S/N=3). The sensitivity was 438.0 (± 2.5) μA mM(-1). It is expected that the method presented here can not only be easily extended to other redox enzymes or proteins, but also be used as an electrochemical sensing devices for the determination of H2O2 in cell extracts or urine.

  16. Probing Protein 3D Structures and Conformational Changes Using Electrochemistry-Assisted Isotope Labeling Cross-Linking Mass Spectrometry

    Science.gov (United States)

    Zheng, Qiuling; Zhang, Hao; Wu, Shiyong; Chen, Hao

    2016-05-01

    This study presents a new chemical cross-linking mass spectrometry (MS) method in combination with electrochemistry and isotope labeling strategy for probing both protein three-dimensional (3D) structures and conformational changes. For the former purpose, the target protein/protein complex is cross-linked with equal mole of premixed light and heavy isotope labeled cross-linkers carrying electrochemically reducible disulfide bonds (i.e., DSP-d0 and DSP-d8 in this study, DSP = dithiobis[succinimidyl propionate]), digested and then electrochemically reduced followed with online MS analysis. Cross-links can be quickly identified because of their reduced intensities upon electrolysis and the presence of doublet isotopic peak characteristics. In addition, electroreduction converts cross-links into linear peptides, facilitating MS/MS analysis to gain increased information about their sequences and modification sites. For the latter purpose of probing protein conformational changes, an altered procedure is adopted, in which the protein in two different conformations is cross-linked using DSP-d0 and DSP-d8 separately, and then the two protein samples are mixed in 1:1 molar ratio. The merged sample is subjected to digestion and electrochemical mass spectrometric analysis. In such a comparative cross-linking experiment, cross-links could still be rapidly recognized based on their responses to electrolysis. More importantly, the ion intensity ratios of light and heavy isotope labeled cross-links reveal the conformational changes of the protein, as exemplified by examining the effect of Ca2+ on calmodulin conformation alternation. This new cross-linking MS method is fast and would have high value in structural biology.

  17. Probing the nature of electron transfer in metalloproteins on graphene-family materials as nanobiocatalytic scaffold using electrochemistry

    Science.gov (United States)

    Gupta, Sanju; Irihamye, Aline

    2015-03-01

    Graphene-based nanomaterials have shown great promise not only in nanoelectronics due to ultrahigh electron mobility but also as biocatalytic scaffolds owing to irreversible protein surface adsorption and facilitating direct electron transfer. In this work, we synthesized stable dispersions of graphene using liquid-phase exfoliation approach based on non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py-1SO3), 1-pyrenemethylamine salt (Py - Me-NH2) and Pluronic® P-123 surfactant using only water as solvent compatible with biomolecules. The resulting graphene nanoplatelets (Gr_LPE) are characterized by a combination of analytical (microscopy and spectroscopy) techniques revealing mono- to few-layer graphene displaying that the exfoliation efficiency strongly depends upon the type of pyrene-based salts and organic surfactants. Moreover being completely water-based approach, we build robust nanoscaffolds of graphene-family nanomaterials (GFNs) namely, monolayer graphene, Gr_LPE (the one prepared with Pluronic® P-123), graphene oxide (GO) and its reduced form (rGO) on glassy carbon electrode surface with three important metalloproteins include cytochrome c (Cyt c) [for electron transfer], myoglobin (Mb) [for oxygen storage] and horseradish peroxidase (HRP) [for catalyzing the biochemical reaction]. In order to demonstrate the nanobiocatalytical activity of these proteins, we used electrochemical interfacial direct electron transfer (DET) kinetics and attempt to determine the rate constant (kET) using two different analytical approaches namely, linear sweep voltammetry and Laviron's theory. We elucidated that all of the metalloproteins retain their structural integrity (secondary structure) upon forming mixtures with GFNs confirmed through optical and vibrational spectroscopy and biological activity using electrochemistry. Among the GFNs studied, Gr-LPE, GO and rGO support the efficient electrical wiring of the redox centers (with an

  18. Sol-gel derived silica/chitosan/Fe3O4 nanocomposite for direct electrochemistry and hydrogen peroxide biosensing

    Science.gov (United States)

    Satvekar, R. K.; Rohiwal, S. S.; Tiwari, A. P.; Raut, A. V.; Tiwale, B. M.; Pawar, S. H.

    2015-01-01

    A novel strategy to fabricate hydrogen peroxide third generation biosensor has been developed from sol-gel of silica/chitosan (SC) organic-inorganic hybrid material assimilated with iron oxide magnetic nanoparticles (Fe3O4). The large surface area of Fe3O4 and porous morphology of the SC composite facilitates a high loading of horseradish peroxidase (HRP). Moreover, the entrapped enzyme preserves its conformation and biofunctionality. The fabrication of hydrogen peroxide biosensor has been carried out by drop casting of the SC/F/HRP nanocomposite on glassy carbon electrode (GCE) for study of direct electrochemistry. The x-ray diffraction (XRD) pattern and transmission electron microscopy (TEM) confirms the phase purity and particle size of as-synthesized Fe3O4 nanoparticles, respectively. The nanocomposite was characterized by UV-vis spectroscopy, fluorescence spectroscopy and Fourier transform infrared (FTIR) for the characteristic structure and conformation of enzyme. The surface topographies of the nanocomposite thin films were investigated by scanning electron microscopy (SEM). Dynamic light scattering (DLS) was used to determine the particle size distribution. The electrostatic interactions of the SC composite with Fe3O4 nanoparticles were studied by the zeta potential measurement. Electrochemical impedance spectroscopy (EIS) of the SC/F/HRP/GCE electrode displays Fe3O4 nanoparticles as an excellent candidate for electron transfer. The SC/F/HRP/GCE exhibited a pair of well-defined quasi reversible cyclic voltammetry peaks due to the redox couple of HRP-heme Fe (III)/Fe (II) in pH 7.0 potassium phosphate buffer. The biosensor was employed to detect H2O2 with linear range of 5 μM to 40 μM and detection limit of 5 μM. The sensor displays excellent selectivity, sensitivity, good reproducibility and long term stability.

  19. Electrochemistry and analytical determination of lysergic acid diethylamide (LSD) via adsorptive stripping voltammetry.

    Science.gov (United States)

    Merli, Daniele; Zamboni, Daniele; Protti, Stefano; Pesavento, Maria; Profumo, Antonella

    2014-12-01

    Lysergic acid diethylamide (LSD) is hardly detectable and quantifiable in biological samples because of its low active dose. Although several analytical tests are available, routine analysis of this drug is rarely performed. In this article, we report a simple and accurate method for the determination of LSD, based on adsorptive stripping voltammetry in DMF/tetrabutylammonium perchlorate, with a linear range of 1-90 ng L(-1) for deposition times of 50s. LOD of 1.4 ng L(-1) and LOQ of 4.3 ng L(-1) were found. The method can be also applied to biological samples after a simple extraction with 1-chlorobutane.

  20. Electrochemical reaction and heat balance. Reduction of Peltier effect and electro-chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ozeki, Toru; Watanabe, Iwao; Ikeda, Shigeyoshi

    1988-02-05

    This report describes the Peltier heat which accompanies an electrochemical reaction, and the cyclicovoltamo thermometry (CVT) which has applied the effect. When the current is restricted, heat generated by Joule's heat or overvoltage depends on the electrode structure, whereas Pertier's heat depends only on a type of the electrode reaction, wherein the entropy change of the electrode reaction can be known by subtracting the heat of transpotation from the Pertier coefficient; entropy of metal ions determines the change. Application of the above is to combine, in a system wherein 2 or more electrode reactions compete, a thermometry and a cyclic voltametry to constantly measure the heat in order to estimate the current contribution of the separated two reactions. Very effective information was obtained on the analysis of the electrode reactions, in addition to the conventional two kinds of informations, current and voltage. (5 figs, 7 refs)

  1. Direct electrochemistry of Shewanella loihica PV-4 on gold nanoparticles-modified boron-doped diamond electrodes fabricated by layer-by-layer technique.

    Science.gov (United States)

    Wu, Wenguo; Xie, Ronggang; Bai, Linling; Tang, Zuming; Gu, Zhongze

    2012-05-01

    Microbial Fuel Cells (MFCs) are robust devices capable of taping biological energy, converting pollutants into electricity through renewable biomass. The fabrication of nanostructured electrodes with good bio- and electrochemical activity, play a profound role in promoting power generation of MFCs. Au nanoparticles (AuNPs)-modified Boron-Doped Diamond (BDD) electrodes are fabricated by layer-by-layer (LBL) self-assembly technique and used for the direct electrochemistry of Shewanella loihica PV-4 in an electrochemical cell. Experimental results show that the peak current densities generated on the Au/PAH multilayer-modified BDD electrodes increased from 1.25 to 2.93 microA/cm(-2) as the layer increased from 0 to 6. Different cell morphologies of S. loihica PV-4 were also observed on the electrodes and the highest density of cells was attached on the (Au/PAH)6/BDD electrode with well-formed three-dimensional nanostructure. The electrochemistry of S. loihica PV-4 was enhanced on the (Au/PAH)4/BDD electrode due to the appropriate amount of AuNPsand thickness of PAH layer.

  2. Atomic-scale electrochemistry on the surface of a manganite by scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Rama K., E-mail: rvv@ornl.gov; Tselev, Alexander; Baddorf, Arthur P. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); ORNL Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Gianfrancesco, Anthony G. [UT/ORNL Bredesen Center, University of Tennessee, Knoxville, Tennessee 37996 (United States); Kalinin, Sergei V. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); ORNL Institute for Functional Imaging of Materials, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); UT/ORNL Bredesen Center, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2015-04-06

    The doped manganese oxides (manganites) have been widely studied for their colossal magnetoresistive effects, for potential applications in oxide spintronics, electroforming in resistive switching devices, and are materials of choice as cathodes in modern solid oxide fuel cells. However, little experimental knowledge of the dynamics of the surfaces of perovskite manganites at the atomic scale exists. Here, through in-situ scanning tunneling microscopy (STM), we demonstrate atomic resolution on samples of La{sub 0.625}Ca{sub 0.375}MnO{sub 3} grown on (001) SrTiO{sub 3} by pulsed laser deposition. Furthermore, by applying triangular DC waveforms of increasing amplitude to the STM tip, and measuring the tunneling current, we demonstrate the ability to both perform and monitor surface electrochemical processes at the atomic level, including formation of oxygen vacancies and removal and deposition of individual atomic units or clusters. Our work paves the way for better understanding of surface oxygen reactions in these systems.

  3. Colloidal laponite nanoparticles: extended application in direct electrochemistry of glucose oxidase and reagentless glucose biosensing.

    Science.gov (United States)

    Shan, Dan; Zhang, Jing; Xue, Huai-Guo; Ding, Shou-Nian; Cosnier, Serge

    2010-02-15

    The direct electron transfer (DET) between glucose oxidase (GOD) and the underlying glassy carbon electrode (GCE) can be readily achieved via colloidal laponite nanoparticles as immobilization matrix. Cyclic voltammetry of laponite/GOD/GCE, in anaerobic phosphate buffer solution (PBS, 0.1M, pH 5.0), showed a pair of stable and quasi-reversible peaks at potentials E(pa)=-0.372 V and E(pc)=-0.391 V vs. SCE, provoked by the prosthetic FAD group linked to the protein. The electrochemical reaction of laponite/GOD/GCE exhibited a surface-controlled process with the apparent heterogeneous electron transfer rate constant (k(s)) of 6.52 s(-1) and charge-transfer coefficient (alpha) of 0.5. The experiments of FTIR and UV-vis spectroscopy demonstrate that the immobilized GOD on colloidal laponite nanoparticles retained its native structure and its biocatalytic ability to its substrates. Based on the decrease of oxygen electrocatalytic signal, the proposed laponite/GOD/GCE was successfully applied in the reagentless glucose sensing at -0.45 V. The proposed electrode exhibited fast amperometric response (8s), broad linear range (2.0x10(-5)-1.9x10(-3) M), good sensitivity (4.8+/-0.5 mA M(-1) cm(-2)), low detection limit (1.0x10(-5) M) at a signal-to-noise ratio of 3, and excellent selectivity.

  4. Electrochemistry and determination of cefdinir by voltammetric and computational approaches

    Directory of Open Access Journals (Sweden)

    İbrahim Hüdai Taşdemir

    2014-12-01

    Full Text Available The oxidation and reduction behavior of cefdinir (CEF was studied by experimental methods and computational calculations at B3LYP/6-31+G (d//AM1. Voltammetric studies were carried out based on two irreversible reduction peaks at approximately −0.5 and −1.2 V on a hanging mercury drop electrode (HMDE and on one irreversible oxidation peak at approximately 1.0 V on a glassy carbon electrode (GCE versus Ag/AgCl, KCl (3.0M in Britton–Robinson (BR buffer at pH 4.2 and 5.0, respectively. Differential pulse adsorptive stripping voltammetric methods have been developed and validated for determination of CEF in different samples. The linear range was established as 0.25–40.0 μM for HMDE and 0.40–10.0 μM for GCE. Limit of quantification was calculated to be 0.20 and 0.26 μM for HMDE and GCE, respectively. These methods were successfully applied to assay the drug in tablets and human serum with good recoveries between 92.7% and 107.3% having relative standard deviation less than 10%.

  5. Surfaces of action: cells and membranes in electrochemistry and the life sciences.

    Science.gov (United States)

    Grote, Mathias

    2010-09-01

    The term 'cell', in addition to designating fundamental units of life, has also been applied since the nineteenth century to technical apparatuses such as fuel and galvanic cells. This paper shows that such technologies, based on the electrical effects of chemical reactions taking place in containers, had a far-reaching impact on the concept of the biological cell. My argument revolves around the controversy over oxidative phosphorylation in bioenergetics between 1961 and 1977. In this scientific conflict, a two-level mingling of technological culture, physical chemistry and biological research can be observed. First, Peter Mitchell explained the chemiosmotic hypothesis of energy generation by representing cellular membrane processes via an analogy to fuel cells. Second, in the associated experimental scrutiny of membranes, material cell models were devised that reassembled spatialized molecular processes in vitro. Cells were thus modelled both on paper and in the test tube not as morphological structures but as compartments able to perform physicochemical work. The story of cells and membranes in bioenergetics points out the role that theories and practices in physical chemistry had in the molecularization of life. These approaches model the cell as a 'topology of molecular action', as I will call it, and it involves concepts of spaces, surfaces and movements. They epitomize an engineer's vision of the organism that has influenced diverse fields in today's life sciences.

  6. Direct electrochemistry and electrocatalysis of lobetyolin via magnetic functionalized reduced graphene oxide film fabricated electrochemical sensor.

    Science.gov (United States)

    Sun, Bolu; Gou, Xiaodan; Bai, Ruibin; Abdelmoaty, Ahmed Attia Ahmed; Ma, Yuling; Zheng, Xiaoping; Hu, Fangdi

    2017-05-01

    A novel lobetyolin electrochemical sensor based on a magnetic functionalized reduced graphene oxide/Nafion nanohybrid film has been introduced in this work. The magnetic functionalized reduced graphene oxide was characterized by fourier transform infrared spectroscopy, atomic force microscope, X-ray diffraction, transmission electron microscopy and thermogravimetric analysis. The scanning electron microscopy characterized the morphology and microstructure of the prepared sensors, and the electrochemical effective surface areas of the prepared sensors were also calculated by chronocoulometry method. The electrochemical behavior of lobetyolin on the magnetic functionalized reduced graphene oxide/Nafion nanohybrid modified glassy carbon electrode was investigated by cyclic voltammetry and differential pulse voltammetry in a phosphate buffer solution of pH6.0. The electron-transfer coefficient (α), electron transfer number (n), and electrode reaction rate constant (Κs) were calculated as 0.78, 0.73, and 4.63s(-1), respectively. Under the optimized conditions, the sensor based on magnetic functionalized reduced graphene oxide/Nafion showed a linear voltammetric response to the lobetyolin concentration at 1.0×10(-7) to 1.0×10(-4)mol/L with detection limit (S/N=3)of 4.3×10(-8)mol/L. The proposed sensor also displayed acceptable reproducibility, long-term stability, and high selectivity, and performs well for analysis of lobetyolin in real samples. The voltammetric sensor was successfully applied to detect lobetyolin in Codonopsis pilosula with recovery values in the range of 96.12%-102.66%.

  7. Magnetite-graphene for the direct electrochemistry of hemoglobin and its biosensing application

    Energy Technology Data Exchange (ETDEWEB)

    He Yaping; Sheng Qinglin [Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi' an, Shaanxi 710069 (China); Zheng Jianbin, E-mail: zhengjb@nwu.edu.c [Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi' an, Shaanxi 710069 (China); Wang Minzhi [Institute of Analytical Science/Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Northwest University, Xi' an, Shaanxi 710069 (China); Liu Bin [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry (Ministry of Education), Northwest University, Xi' an, Shaanxi 710069 (China); Department of Chemistry, Xianyang Normal University, Xianyang, Shaanxi 712000 (China)

    2011-02-01

    Magnetite-graphene (Fe{sub 3}O{sub 4}-GE) was prepared via a simple effective chemical precipitation method, followed by the chemical reduction with hydrazine. Fe{sub 3}O{sub 4}-GE was characterized by Raman spectroscopy, transmission electron microscope, X-ray powder diffraction and electrochemical methods. A hydrogen peroxide (H{sub 2}O{sub 2}) biosensor was structured by immobilizing hemoglobin (Hb) into Fe{sub 3}O{sub 4}-GE for the first time. UV-vis and Fourier transform infrared spectra were employed to characterize Hb retained original structure in the resulting Hb-Fe{sub 3}O{sub 4}-GE membrane. Electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with E{sub pa} = -0.285 V and E{sub pc} = -0.363 V (vs. SCE) in phosphate buffer solution (0.1 mol/L, pH 7.0) at the scan rate of 100 mV/s. The Hb-Fe{sub 3}O{sub 4}-GE showed a better synergistic electrochemical effect for the reduced process of H{sub 2}O{sub 2}. The biosensor displayed a fast response time (<3 s) and broad linear response to H{sub 2}O{sub 2} in the range from 1.50 to 585 {mu}mol/L with a relatively low detection limit of 0.5 {mu}mol/L (S/N = 3). Moreover, the biosensor could be applied in practical analysis and exhibit good reproducibility and long-term stability.

  8. Redox-dependent spatially resolved electrochemistry at graphene and graphite step edges.

    Science.gov (United States)

    Güell, Aleix G; Cuharuc, Anatolii S; Kim, Yang-Rae; Zhang, Guohui; Tan, Sze-yin; Ebejer, Neil; Unwin, Patrick R

    2015-04-28

    The electrochemical (EC) behavior of mechanically exfoliated graphene and highly oriented pyrolytic graphite (HOPG) is studied at high spatial resolution in aqueous solutions using Ru(NH3)6(3+/2+) as a redox probe whose standard potential sits close to the intrinsic Fermi level of graphene and graphite. When scanning electrochemical cell microscopy (SECCM) data are coupled with that from complementary techniques (AFM, micro-Raman) applied to the same sample area, different time-dependent EC activity between the basal planes and step edges is revealed. In contrast, other redox couples (ferrocene derivatives) whose potential is further removed from the intrinsic Fermi level of graphene and graphite show uniform and high activity (close to diffusion-control). Macroscopic voltammetric measurements in different environments reveal that the time-dependent behavior after HOPG cleavage, peculiar to Ru(NH3)6(3+/2+), is not associated particularly with any surface contaminants but is reasonably attributed to the spontaneous delamination of the HOPG with time to create partially coupled graphene layers, further supported by conductive AFM measurements. This process has a major impact on the density of states of graphene and graphite edges, particularly at the intrinsic Fermi level to which Ru(NH3)6(3+/2+) is most sensitive. Through the use of an improved voltammetric mode of SECCM, we produce movies of potential-resolved and spatially resolved HOPG activity, revealing how enhanced activity at step edges is a subtle effect for Ru(NH3)6(3+/2+). These latter studies allow us to propose a microscopic model to interpret the EC response of graphene (basal plane and edges) and aged HOPG considering the nontrivial electronic band structure.

  9. Probing the nature of electron transfer in metalloproteins on graphene-family materials as nanobiocatalytic scaffold using electrochemistry

    Directory of Open Access Journals (Sweden)

    Sanju Gupta

    2015-03-01

    Full Text Available Graphene-based nanomaterials have shown great promise not only in nanoelectronics due to ultrahigh electron mobility but also as biocatalytic scaffolds owing to irreversible protein surface adsorption and facilitating direct electron transfer. In this work, we synthesized stable dispersions of graphene using liquid-phase exfoliation approach based on non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py–1SO3, 1-pyrenemethylamine salt (Py − Me-NH2 and Pluronic® P-123 surfactant using only water as solvent compatible with biomolecules. The resulting graphene nanoplatelets (Gr_LPE are characterized by a combination of analytical (microscopy and spectroscopy techniques revealing mono- to few-layer graphene displaying that the exfoliation efficiency strongly depends upon the type of pyrene-based salts and organic surfactants. Moreover being completely water-based approach, we build robust nanoscaffolds of graphene-family nanomaterials (GFNs namely, monolayer graphene, Gr_LPE (the one prepared with Pluronic® P-123, graphene oxide (GO and its reduced form (rGO on glassy carbon electrode surface with three important metalloproteins include cytochrome c (Cyt c [for electron transfer], myoglobin (Mb [for oxygen storage] and horseradish peroxidase (HRP [for catalyzing the biochemical reaction]. In order to demonstrate the nanobiocatalytical activity of these proteins, we used electrochemical interfacial direct electron transfer (DET kinetics and attempt to determine the rate constant (kET using two different analytical approaches namely, linear sweep voltammetry and Laviron’s theory. We elucidated that all of the metalloproteins retain their structural integrity (secondary structure upon forming mixtures with GFNs confirmed through optical and vibrational spectroscopy and biological activity using electrochemistry. Among the GFNs studied, Gr-LPE, GO and rGO support the efficient electrical wiring of the redox centers

  10. Probing the nature of electron transfer in metalloproteins on graphene-family materials as nanobiocatalytic scaffold using electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sanju, E-mail: sanju.gupta@wku.edu [Department of Physics and Astronomy, Western Kentucky University, 1906 College Heights Blvd. Bowling Green, KY 42101-3576 (United States); Biotechnology Center, Western Kentucky University, 1906 College Heights Blvd. Bowling Green, KY 42101-3576 (United States); Irihamye, Aline [Gatton Academy of Mathematics and Science in Kentucky, Western Kentucky University, 1906 College Heights Blvd. Bowling Green, KY 42101-3576 (United States)

    2015-03-15

    Graphene-based nanomaterials have shown great promise not only in nanoelectronics due to ultrahigh electron mobility but also as biocatalytic scaffolds owing to irreversible protein surface adsorption and facilitating direct electron transfer. In this work, we synthesized stable dispersions of graphene using liquid-phase exfoliation approach based on non-covalent interactions between graphene and 1-pyrenesulfonic acid sodium salt (Py–1SO{sub 3}), 1-pyrenemethylamine salt (Py − Me-NH{sub 2}) and Pluronic{sup ®} P-123 surfactant using only water as solvent compatible with biomolecules. The resulting graphene nanoplatelets (Gr-LPE) are characterized by a combination of analytical (microscopy and spectroscopy) techniques revealing mono- to few-layer graphene displaying that the exfoliation efficiency strongly depends upon the type of pyrene-based salts and organic surfactants. Moreover being completely water-based approach, we build robust nanoscaffolds of graphene-family nanomaterials (GFNs) namely, monolayer graphene, Gr-LPE (the one prepared with Pluronic{sup ®} P-123), graphene oxide (GO) and its reduced form (rGO) on glassy carbon electrode surface with three important metalloproteins include cytochrome c (Cyt c) [for electron transfer], myoglobin (Mb) [for oxygen storage] and horseradish peroxidase (HRP) [for catalyzing the biochemical reaction]. In order to demonstrate the nanobiocatalytical activity of these proteins, we used electrochemical interfacial direct electron transfer (DET) kinetics and attempt to determine the rate constant (k{sub ET}) using two different analytical approaches namely, linear sweep voltammetry and Laviron’s theory. We elucidated that all of the metalloproteins retain their structural integrity (secondary structure) upon forming mixtures with GFNs confirmed through optical and vibrational spectroscopy and biological activity using electrochemistry. Among the GFNs studied, Gr-LPE, GO and rGO support the efficient electrical

  11. In-Situ TEM Electrochemistry of Individual Nanowire and Nanoparticle Electrodes in a Li-Ion Cell

    Science.gov (United States)

    Huang, Jianyu

    2012-02-01

    Recently, we created the first Li-ion electrochemical cell inside a transmission electron microscope (TEM) and observed, in real time with atomic scale resolution, the lithiation/delithiation processes. This experiment opened the door for a suite of experimental studies involving in-situ TEM characterization of Li-ion battery materials. In this presentation, I'll first review our latest progress of using the in-situ electrochemical cell setup inside the TEM to reveal the intrinsic electrochemistry of several high energy density anode materials such as SnO2, ZnO, Si, Ge, Al nanowires, Si nanoparticles, carbon nanotubes, and graphene. Several electrochemical mechanisms were observed and characterized in real-time, including lithiation induced stress, volume changes, phase transformations, pulverization, cracking, embrittlement, and mechanical failure in anode materials. These results indicate the strong material, size and crystallographic orientation dependent electrochemical behavior and degradation mechanisms that occur in Li-ion battery anodes. In the future, we will need further advancements in in-situ characterization for understanding important processes in Li-ion batteries. For example, liquid cells are required in order to examine the electrochemical reactions between battery materials and the standard battery electrolytes, which are ethylene carbonate-based. Furthermore, in-situ studies need to be correlated with electrochemical studies performed on bulk electrodes. I will present a comparison between our in-situ results and electrochemical studies on conventional battery electrodes and highlight how in-situ studies can have important impact on the design of Li-ion batteries. Finally I will discuss outstanding challenging issues and opportunities in the field of Li-ion battery research. [4pt] References: Science 330, 1515 (2010); 330, 1485 (2010); Nano Lett. Doi: 10.1021/nl200412p, 10.1021/nl2024118, 10.1021/nl201684d, 10.1021/nl202088h, ACS Nano, doi: 10

  12. Modeling and experimental validation of CO heterogeneous chemistry and electrochemistry in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Yurkiv, Vitaly

    2010-12-17

    In the present work experimental and numerical modeling studies of the heterogeneously catalyzed and electrochemical oxidation of CO at Nickel/yttria-stabilized zirconia (YSZ) solid oxide fuel cell (SOFC) anode systems were performed to evaluate elementary charge-transfer reaction mechanisms taking place at the three-phase boundary of CO/CO{sub 2} gas-phase, Ni electrode, and YSZ electrolyte. Temperature-programmed desorption and reaction experiments along with density functional theory calculations were performed to determine adsorption/desorption and surface diffusion kinetics as well as thermodynamic data for the CO/CO{sub 2}/Ni and CO/CO{sub 2}/YSZ systems. Based on these data elementary reaction based models with four different charge transfer mechanisms for the electrochemical CO oxidation were developed and applied in numerical simulations of literature experimental electrochemical data such as polarization curves and impedance spectra. Comparison between simulation and experiment demonstrated that only one of the four charge transfer mechanisms can consistently reproduce the electrochemical data over a wide range of operating temperatures and CO/CO{sub 2} gas compositions. (orig.) [German] In der vorliegenden Arbeit wurden experimentelle und numerische Untersuchungen zur heterogen katalysierten und elektrochemischen Oxidation von CO an Anodensystemen (bestehend aus Nickel und yttriumdotiertem Zirkoniumdioxid, YSZ) von Festoxidbrennstoffzellen (engl. Solid Oxide Fuel Cells, SOFCs) ausgefuehrt, um den mikroskopischen Mechanismus der an der CO/CO{sub 2}-Gasphase/Ni-Elektrode/YSZ-Elektrolyt- Dreiphasen-Grenzflaeche ablaufenden Ladungsuebertragungsreaktion aufzuklaeren. Temperaturprogrammierte Desorptionsmessungen (TPD) und Temperaturprogrammierte Reaktionsmessungen (TPR) sowie Dichtefunktionaltheorierechnungen wurden ausgefuehrt, um adsorptions-, desorptions- und reaktionskinetische sowie thermodynamische Daten fuer die CO/CO{sub 2}/Ni- und CO/CO{sub 2}/YSZ

  13. Analysis of Various Bibliometric Indicators for the Evaluation of Scientific Journals and Scientists

    Science.gov (United States)

    Guz, A. N.; Rushchitsky, J. J.

    2013-05-01

    Features of applying bibliometric indicators for scientific journals and scientists are discussed using, as examples, scientists of the S. P. Timoshenko Institute of Mechanics and the journal Prikladnaya Mekhanika ( International Applied Mechanics), which is published by the institute in Russian and by Springer in English. Old and new scientific databases are described and commented on. Consideration is given to citation as the most popular parameter for bibliometric indicators, the Hirsch and Egghe indices as criteria for the evaluation of scientists, the Hirsch index, Impact-Factor, SJR, SNIP, and RIP as criteria for the evaluation of scientific journals, and a new approach to evaluation based on full-text article requests. In 1991-2011, Prikladnaya Mekhanika ( International Applied Mechanics) had highest indicators among all Ukrainian scientific journals: Impact-Factor = 1.740 in 2005, SJR = 0.240 in 2006, RIP = 1.76 in 2006, SNIP = 2.45 in 2011

  14. 碳纳米管的纯化——电化学氧化法%Purification of Carbon Nanotubes Oxidation Method by Using Electrochemistry

    Institute of Scientific and Technical Information of China (English)

    杨占红; 吴浩青; 李晶; 李新海

    2001-01-01

    用电化学氧化法对碳纳米管进行纯化, 从稳态极化曲线出发, 对反应的可行性进行了分析, 考察了支持电解质、 电流密度、 时间等因素对反应的影响, 确定了最佳实验条件, 同时对纯化机理进行了解释.%Carbon nanotubes were purified by use of electrical chemistry oxidation method. In the view of polarization curves it was discussed that electrochemistry method could be used in the purification of carbon nanotubus. The influence of current density, sulfuric acid concentration and reaction time on the reaction was studied, the optimum experimental condition was obtained and the mechanism of purification was also discussed.

  15. End-of-Discharge and End-of-Life Prediction in Lithium-Ion Batteries with Electrochemistry-Based Aging Models

    Science.gov (United States)

    Daigle, Matthew; Kulkarni, Chetan S.

    2016-01-01

    As batteries become increasingly prevalent in complex systems such as aircraft and electric cars, monitoring and predicting battery state of charge and state of health becomes critical. In order to accurately predict the remaining battery power to support system operations for informed operational decision-making, age-dependent changes in dynamics must be accounted for. Using an electrochemistry-based model, we investigate how key parameters of the battery change as aging occurs, and develop models to describe aging through these key parameters. Using these models, we demonstrate how we can (i) accurately predict end-of-discharge for aged batteries, and (ii) predict the end-of-life of a battery as a function of anticipated usage. The approach is validated through an experimental set of randomized discharge profiles.

  16. Depth probing of the hydride formation process in thin Pd films by combined electrochemistry and fiber optics-based in situ UV/vis spectroscopy.

    Science.gov (United States)

    Wickman, Björn; Fredriksson, Mattias; Feng, Ligang; Lindahl, Niklas; Hagberg, Johan; Langhammer, Christoph

    2015-07-15

    We demonstrate a flexible combined electrochemistry and fiber optics-based in situ UV/vis spectroscopy setup to gain insight into the depth evolution of electrochemical hydride and oxide formation in Pd films with thicknesses of 20 and 100 nm. The thicknesses of our model systems are chosen such that the films are thinner or significantly thicker than the optical skin depth of Pd to create two distinctly different situations. Low power white light is irradiated on the sample and analyzed in three different configurations; transmittance through, and, reflectance from the front and the back side of the film. The obtained optical sensitivities correspond to fractions of a monolayer of adsorbed or absorbed hydrogen (H) and oxygen (O) on Pd. Moreover, a combined simultaneous readout obtained from the different optical measurement configurations provides mechanistic insights into the depth-evolution of the studied hydrogenation and oxidation processes.

  17. Luminescent cyclometalated alkynylplatinum(II) complexes with a tridentate pyridine-based N-heterocyclic carbene ligand: synthesis, characterization, electrochemistry, photophysics, and computational studies.

    Science.gov (United States)

    Leung, Sammual Yu-Lut; Lam, Elizabeth Suk-Hang; Lam, Wai Han; Wong, Keith Man-Chung; Wong, Wing-Tak; Yam, Vivian Wing-Wah

    2013-07-29

    A new class of luminescent alkynylplatinum(II) complexes with a tridentate pyridine-based N-heterocyclic carbene (2,6-bis(1-butylimidazol-2-ylidenyl)pyridine) ligand, [Pt(II)(C^N^C)(C≡CR)][PF6], and their chloroplatinum(II) precursor complex, [Pt(II)(C^N^C)Cl][PF6], have been synthesized and characterized. One of the alkynylplatinum(II) complexes has also been structurally characterized by X-ray crystallography. The electrochemistry, electronic absorption and luminescence properties of the complexes have been studied. Nanosecond transient absorption (TA) spectroscopy has also been performed to probe the nature of the excited state. The origin of the absorption and emission properties has been supported by computational studies.

  18. 自动变换量程的电化学仪设计%Design of Automatic Range-changing Electrochemistry Instrument

    Institute of Scientific and Technical Information of China (English)

    于航; 朱纪军

    2013-01-01

      为了解决电化学实验由于固定量程造成实验结果不正确或不精确的问题,本文以TMS320F28335微控制器为核心,提供了一种在实验过程中可根据当前反应电流改变量程的电化学仪设计方案。对于仪器重要组成部分如恒电位仪、I/V转换电路及波形发生电路介绍了其设计方法,详细阐述了下位机与上位机软件的工作流程。仪器结构简单、成本低廉,利用原理样机进行了循环伏安法实验并通过上位机软件绘制出伏安图,实验结果表明:设计方案可行,电化学仪能够正常工作。%In order to solve the problem caused by Fixed-range in electrochemistry experiments,a Range-changing electrochemistry Measuring Based on TMS320F28335 microcontroller is designed.We introduced the important parts of the instrument such as potentiostat,I/V conversion circuit,waveform generator.Elaborate the process of the software.The instrument has simple structure and low cost,A cyclic voltammetry experiment is carried out to test the prototype,the experimental show that the scheme is available.

  19. Magnetic effects in electrochemistry

    Directory of Open Access Journals (Sweden)

    NEBOJSA D. NIKOLIC

    2005-05-01

    Full Text Available The effect of imposed magnetic fields onto the electrodeposition of magnetic (nickel and non – magnetic (copper metals was analysed. Also, magnetic properties of electrochemically obtained nanocontacts were examined. An effort to establish a possible correlation between the morphologies of the nanocontacts and the effect of the very large ballistic magnetoresistance (BMR effect was made.

  20. Perspectives on Applied Ethics

    OpenAIRE

    2007-01-01

    Applied ethics is a growing, interdisciplinary field dealing with ethical problems in different areas of society. It includes for instance social and political ethics, computer ethics, medical ethics, bioethics, envi-ronmental ethics, business ethics, and it also relates to different forms of professional ethics. From the perspective of ethics, applied ethics is a specialisation in one area of ethics. From the perspective of social practice applying eth-ics is to focus on ethical aspects and ...

  1. Advances in Applied Mechanics

    OpenAIRE

    2014-01-01

    Advances in Applied Mechanics draws together recent significant advances in various topics in applied mechanics. Published since 1948, Advances in Applied Mechanics aims to provide authoritative review articles on topics in the mechanical sciences, primarily of interest to scientists and engineers working in the various branches of mechanics, but also of interest to the many who use the results of investigations in mechanics in various application areas, such as aerospace, chemical, civil, en...

  2. Applied Neuroscience Laboratory Complex

    Data.gov (United States)

    Federal Laboratory Consortium — Located at WPAFB, Ohio, the Applied Neuroscience lab researches and develops technologies to optimize Airmen individual and team performance across all AF domains....

  3. Estudio comparativo de la resolución de problemas en el rendimiento estudiantil en el contenido de electroquímica (COMPARATIVE STUDY OF THE RESOLUTION OF PROBLEMS IN THE STUDENT YIELD ON THE CONTENT OF ELECTROCHEMISTRY

    Directory of Open Access Journals (Sweden)

    Di’ Bacco Vera Lucia

    2009-04-01

    Full Text Available Resumen:Este estudio comparó las metodologías de resolución de problemas de: Reif, Durán y García, a través del rendimiento estudiantil en el contenido de electroquímica. La muestra estuvo representada por 73 estudiantes del Primer Año de Ciencias de la Unidad Educativa Nacional "El Eneal" del Municipio Crespo, Estado Lara-Venezuela, año escolar 2006-2007. Veinticinco (25 aprendices pertenecen al grupo experimental uno (GE1 y los grupos experimentales dos (GE2 y tres (GE3 están conformados por veinticuatro (24 estudiantes cada uno. Antes de la aplicación de las metodologías, se administró una prueba de conocimientos previos a los tres grupos experimentales; determinándose que los grupos son homogéneos. Al finalizar las tres metodologías, se les aplicó a los tres grupos una post-prueba. Los resultados permitieron concluir que no existe diferencia, estadísticamente significativa, entre el rendimiento estudiantil, en términos del promedio de calificaciones, por los tres grupos que recibieron los tratamientos con las tres estrategias de resolución de problemas utilizadas.Abstract:This study compared the methodologies of resolution of problems: Reif, and García Durán, through student performance on the content of electrochemistry. The sample was represented by 73 students from the First Year of Science Education National Unity "The Eneal" Crespo Municipio Crespo, Estado Lara-Venezuela, 2006-2007 school year. Twenty-five (25 trainees belong to an experimental group (GE1 and two experimental groups (GE2 and three (GE3 are composed of twenty-four (24 students each. Before the application of methodologies, were administered a test of knowledge prior to the three experimental groups, determined that the groups are homogeneous. At the end of the three methodologies were applied to all three groups a post-test.The results allowed concluding that statistically significant difference between the student yields in terms of the average of

  4. What are applied ethics?

    Science.gov (United States)

    Allhoff, Fritz

    2011-03-01

    This paper explores the relationships that various applied ethics bear to each other, both in particular disciplines and more generally. The introductory section lays out the challenge of coming up with such an account and, drawing a parallel with the philosophy of science, offers that applied ethics may either be unified or disunified. The second section develops one simple account through which applied ethics are unified, vis-à-vis ethical theory. However, this is not taken to be a satisfying answer, for reasons explained. In the third section, specific applied ethics are explored: biomedical ethics; business ethics; environmental ethics; and neuroethics. These are chosen not to be comprehensive, but rather for their traditions or other illustrative purposes. The final section draws together the results of the preceding analysis and defends a disunity conception of applied ethics.

  5. Mesothelioma Applied Research Foundation

    Science.gov (United States)

    ... Percentage Donations Tribute Wall Other Giving/Fundraising Opportunities Bitcoin Donation Form FAQs Speak with Mary Hesdorffer, Nurse ... Percentage Donations Tribute Wall Other Giving/Fundraising Opportunities Bitcoin Donation Form FAQs © 2017 Mesothelioma Applied Research Foundation, ...

  6. Applied eye tracking research

    NARCIS (Netherlands)

    Jarodzka, Halszka

    2011-01-01

    Jarodzka, H. (2010, 12 November). Applied eye tracking research. Presentation and Labtour for Vereniging Gewone Leden in oprichting (VGL i.o.), Heerlen, The Netherlands: Open University of the Netherlands.

  7. Computer and Applied Ethics

    OpenAIRE

    越智, 貢

    2014-01-01

    With this essay I treat some problems raised by the new developments in science and technology, that is, those about Computer Ethics to show how and how far Applied Ethics differs from traditional ethics. I take up backgrounds on which Computer Ethics rests, particularly historical conditions of morality. Differences of conditions in time and space explain how Computer Ethics and Applied Ethics are not any traditional ethics in concrete cases. But I also investigate the normative rea...

  8. Development of Control System for Electrochemistry/Electrospray Ionization Source%电化学电喷雾电离源控制系统的研制

    Institute of Scientific and Technical Information of China (English)

    凌星; 丁传凡

    2012-01-01

    控制系统是电化学电喷雾电离源的核心部件及研制难点.本研究通过单片机控制数模、模数转换及蓝牙无线通讯模块构建了一套电化学电喷雾电离源(EC/ESI source)的控制系统.利用此系统及一种同轴式探针组成了完整的电化学电喷雾电离源,对9,10-二苯基蒽进行了循环伏安及在线电化学/电喷雾电离质谱(Online EC/ESI-MS)测试.结果表明:此系统具有高达±1 mV的电势控制精度,电流测量精度优于±0.1 μA(增益为0.01 V/μA)或±0.01 μA(增益为0.1 V/μA).本系统具有成本低廉,可在电喷雾高压上安全悬浮,易于操控的特点.%A control system for an electrochemistry/electrospray ionization source (EC/ESI source) was designed and fabricated. The system includes two parts, a homemade embedded potentiostat floated on electrospray high voltage, and a remote computer, which communicates with the potentiostat through a Bluetooth wireless interface. The accuracy of potential is controlled in the range of +1 mV, and the accuracies of the current measurements are +0. 1 uA (gain = 0. 01 V/uA) and +0. 01 μA (gain = 0.1 V/μA). The performance of the control system was tested by cyclic voltammetry and online electrochemistry/electrospray ionization mass spectrometry (online EC/ESI-MS) using 9,10-diphenylanthrance as a model compound. Accurate potential control was achieved and most importantly, 9,10-diphenylanthrance, a non-polar compound usually undetectable by electrospray ionization mass spectrometry, was detected in high abundance.

  9. Applied chemical engineering thermodynamics

    CERN Document Server

    Tassios, Dimitrios P

    1993-01-01

    Applied Chemical Engineering Thermodynamics provides the undergraduate and graduate student of chemical engineering with the basic knowledge, the methodology and the references he needs to apply it in industrial practice. Thus, in addition to the classical topics of the laws of thermodynamics,pure component and mixture thermodynamic properties as well as phase and chemical equilibria the reader will find: - history of thermodynamics - energy conservation - internmolecular forces and molecular thermodynamics - cubic equations of state - statistical mechanics. A great number of calculated problems with solutions and an appendix with numerous tables of numbers of practical importance are extremely helpful for applied calculations. The computer programs on the included disk help the student to become familiar with the typical methods used in industry for volumetric and vapor-liquid equilibria calculations.

  10. PSYCHOANALYSIS AS APPLIED AESTHETICS.

    Science.gov (United States)

    Richmond, Stephen H

    2016-07-01

    The question of how to place psychoanalysis in relation to science has been debated since the beginning of psychoanalysis and continues to this day. The author argues that psychoanalysis is best viewed as a form of applied art (also termed applied aesthetics) in parallel to medicine as applied science. This postulate draws on a functional definition of modernity as involving the differentiation of the value spheres of science, art, and religion. The validity criteria for each of the value spheres are discussed. Freud is examined, drawing on Habermas, and seen to have erred by claiming that the psychoanalytic method is a form of science. Implications for clinical and metapsychological issues in psychoanalysis are discussed.

  11. Applied Literature for Healing,

    Directory of Open Access Journals (Sweden)

    Susanna Marie Anderson

    2014-11-01

    Full Text Available In this qualitative research study interviews conducted with elite participants serve to reveal the underlying elements that unite the richly diverse emerging field of Applied Literature. The basic interpretative qualitative method included a thematic analysis of data from the interviews yielding numerous common elements that were then distilled into key themes that elucidated the beneficial effects of engaging consciously with literature. These themes included developing a stronger sense of self in balance with an increasing connection with community; providing a safe container to engage challenging and potentially overwhelming issues from a stance of empowered action; and fostering a healing space for creativity. The findings provide grounds for uniting the work being done in a range of helping professions into a cohesive field of Applied Literature, which offers effective tools for healing, transformation and empowerment. Keywords: Applied Literature, Bibliotherapy, Poetry Therapy, Arts in Corrections, Arts in Medicine

  12. Applied mathematics made simple

    CERN Document Server

    Murphy, Patrick

    1982-01-01

    Applied Mathematics: Made Simple provides an elementary study of the three main branches of classical applied mathematics: statics, hydrostatics, and dynamics. The book begins with discussion of the concepts of mechanics, parallel forces and rigid bodies, kinematics, motion with uniform acceleration in a straight line, and Newton's law of motion. Separate chapters cover vector algebra and coplanar motion, relative motion, projectiles, friction, and rigid bodies in equilibrium under the action of coplanar forces. The final chapters deal with machines and hydrostatics. The standard and conte

  13. Introduction to applied thermodynamics

    CERN Document Server

    Helsdon, R M; Walker, G E

    1965-01-01

    Introduction to Applied Thermodynamics is an introductory text on applied thermodynamics and covers topics ranging from energy and temperature to reversibility and entropy, the first and second laws of thermodynamics, and the properties of ideal gases. Standard air cycles and the thermodynamic properties of pure substances are also discussed, together with gas compressors, combustion, and psychrometry. This volume is comprised of 16 chapters and begins with an overview of the concept of energy as well as the macroscopic and molecular approaches to thermodynamics. The following chapters focus o

  14. Retransmission Steganography Applied

    CERN Document Server

    Mazurczyk, Wojciech; Szczypiorski, Krzysztof

    2010-01-01

    This paper presents experimental results of the implementation of network steganography method called RSTEG (Retransmission Steganography). The main idea of RSTEG is to not acknowledge a successfully received packet to intentionally invoke retransmission. The retransmitted packet carries a steganogram instead of user data in the payload field. RSTEG can be applied to many network protocols that utilize retransmissions. We present experimental results for RSTEG applied to TCP (Transmission Control Protocol) as TCP is the most popular network protocol which ensures reliable data transfer. The main aim of the performed experiments was to estimate RSTEG steganographic bandwidth and detectability by observing its influence on the network retransmission level.

  15. On applying cognitive psychology.

    Science.gov (United States)

    Baddeley, Alan

    2013-11-01

    Recent attempts to assess the practical impact of scientific research prompted my own reflections on over 40 years worth of combining basic and applied cognitive psychology. Examples are drawn principally from the study of memory disorders, but also include applications to the assessment of attention, reading, and intelligence. The most striking conclusion concerns the many years it typically takes to go from an initial study, to the final practical outcome. Although the complexity and sheer timescale involved make external evaluation problematic, the combination of practical satisfaction and theoretical stimulation make the attempt to combine basic and applied research very rewarding.

  16. Applied Electromagnetism and Materials

    CERN Document Server

    Moliton, André

    2007-01-01

    Applied Electromagnetism and Materials picks up where the author's Basic Electromagnetism and Materials left off by presenting practical and relevant technological information about electromagnetic material properties and their applications. This book is aimed at senior undergraduate and graduate students as well as researchers in materials science and is the product of many years of teaching basic and applied electromagnetism. Topics range from the spectroscopy and characterization of dielectrics and semiconductors, to non-linear effects and electromagnetic cavities, to ion-beam applications in materials science.

  17. Applied Astronomy: Asteroid Prospecting

    Science.gov (United States)

    Elvis, M.

    2013-09-01

    In the age of asteroid mining the ability to find promising ore-bearing bodies will be valuable. This will give rise to a new discipline- "Applied Astronomy". Just as most geologists work in industry, not in academia, the same will be true of astronomers. Just how rare or common ore-rich asteroids are likely to be, and the skills needed to assay their value, are discussed here, with an emphasis on remote - telescopic - methods. Also considered are the resources needed to conduct extensive surveys of asteroids for prospecting purposes, and the cost and timescale involved. The longer-term need for applied astronomers is also covered.

  18. Africa and Applied Linguistics.

    Science.gov (United States)

    Makoni, Sinfree, Ed.; Meinhof, Ulrike H., Ed.

    2003-01-01

    This collection of articles includes: "Introducing Applied Linguistics in Africa" (Sinfree Makoni and Ulrike H. Meinhof); "Language Ideology and Politics: A Critical Appraisal of French as Second Official Language in Nigeria" (Tope Omoniyi); "The Democratisation of Indigenous Languages: The Case of Malawi" (Themba…

  19. Applying Literature to ELT

    Institute of Scientific and Technical Information of China (English)

    翟悦

    2007-01-01

    Literature is no longer a frightening word to English language learner. Interactive teaching methods and attractive activities can help motivating Chinese university English learners. This essay will first elaborate the reasons to use literature in ELT ( English Language Teaching) class and how to apply literature to ELT class.

  20. Essays on Applied Microeconomics

    Science.gov (United States)

    Mejia Mantilla, Carolina

    2013-01-01

    Each chapter of this dissertation studies a different question within the field of Applied Microeconomics. The first chapter examines the mid- and long-term effects of the 1998 Asian Crisis on the educational attainment of Indonesian children ages 6 to 18, at the time of the crisis. The effects are identified as deviations from a linear trend for…

  1. Applied Statistics with SPSS

    Science.gov (United States)

    Huizingh, Eelko K. R. E.

    2007-01-01

    Accessibly written and easy to use, "Applied Statistics Using SPSS" is an all-in-one self-study guide to SPSS and do-it-yourself guide to statistics. What is unique about Eelko Huizingh's approach is that this book is based around the needs of undergraduate students embarking on their own research project, and its self-help style is designed to…

  2. Direct Electrochemistry of Glucose Oxidase Immobilized on Chitosan-gold Nanoparticle Composite Film on Glassy Carbon Electrodes and Its Biosensing Application

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The direct electrochemistry of glucose oxidase (Gox) immobilized on a composite matrix based on chitosan (CHIT) and Au nanoparticles (Au NP) underlying on a glassy carbon electrode was achieved. The cyclic voltam-metry and electrochemical impedance spectroscopy were used to characterize the modified electrode. In deaerated buffer solutions, the cyclic voltammetry of the composite films of Gox-Au NP-CHIT showed a pair of well-behaved redox peaks that were assigned to the redox reaction of Gox, confirming the effective immobilization of Gox on the composite film. The electron transfer rate constant was estimated to be 15.6 s-1, indicating a high electron transfer between the Gox redox center and electrode. The combination of CHIT and Au NP also promoted the stability of Gox in the composite film and retained its bioactivity, which might have the potential application to glucose determination. The calculated apparent Michaelis-Menten constant was 10.1 mmol·L-1. Furthermore, the proposed biosensor could be used for the determination of glucose in human plasma samples.

  3. Direct Electrochemistry of Horseradish Peroxidase Embedded in Nano-Fe304 Matrix on Paraffin Impregnated Graphite Electrode and Its Electrochemical Catalysis for H2O2

    Institute of Scientific and Technical Information of China (English)

    龚静鸣; 林祥钦

    2003-01-01

    Fe3O4 particles coated with acrylic copolymer (ACP) of about 5--8 nm in diameter were synthesized and used for immobilization of horseradish peroxidase (HRP). Direct electrochemistry of HRP embedded in the nanosized Fe304 solid matrix modified paraffin impregnated graphite electrode (PIGE) was achieved,which is related to the heine Fe(Ⅲ)/Fe(Ⅱ) conversion of HRP. Cyclic voltammetry gave a pair of reproducible and welldefined redox peaks at about Ea of -0.295 V vs. SCE. The standard rate constant k, was determined as 2.7 s-1. It demonstrated that the nano-Fe3O4 solid matrix offers a friendly platform to assemble the HRP protein molecules and enhance the electron transfer rate between the HRP and the electrode. UV-Vis absorption spectra and WrIR spectra studies revealed that the embedded HRP retained its native-like structure. The HRP/Fe3O4/PIGE showed a strong catalytic activity toward H2O2. The voltammetric response was a linear function of H2O2 concentration in the range of 10-140μmol/L with detection limit of 7.3 μmol/L (s/n = 3 ). The apparent Michaelis-Menten constant is calculated to be 0.42 mmol/L.

  4. Direct electrochemistry of dinuclear Cu{sub A} fragment from cytochrome c oxidase of Thermus thermophilus at surfactant modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Rajbongshi, Jitumani [Department of Chemistry, Gauhati University, Guwahati 14 (India); Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 5 (India); Das, Diganta Kumar [Department of Chemistry, Gauhati University, Guwahati 14 (India); Mazumdar, Shyamalava, E-mail: shyamal@tifr.res.i [Department of Chemical Sciences, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai, Maharashtra 5 (India)

    2010-05-01

    Cytochrome c oxidase is ubiquitous enzyme involved in the terminal step of respiratory electron transfer process. The unique binuclear copper center containing bis-dithiolato bridges form a valance delocalized [Cu{sup 1.5+}-Cu{sup 1.5+}] state of the metal center located at the subunit II of cytochrome c oxidase. This metal center acts as the electron entry site of the enzyme and accepts electrons from cytochrome c. Direct electrochemistry of this binuclear copper center containing the water soluble protein obtained by genetically truncating the membrane bound part of the subunit II from Thermus thermophilus was achieved by favorable orientation of the protein on glassy carbon electrode surface promoting efficient electron transfer in the presence of various surfactants. Very reproducible, Nernstian responses are obtained with Cu{sub A}. The redox potential and the electrochemical response were enhanced prominently in case of cationic surfactant CTAB indicating that the nature of the surfactant has a significant effect on the microenvironment of the protein-electrode interface. The results have been used to understand the mechanism of electron transfer from cytochrome c to the copper center during the enzymatic reaction.

  5. The Development of Microsystems and New Applications of Electrochemistry%微系统科技的发展及电化学的新应用

    Institute of Scientific and Technical Information of China (English)

    田昭武; 林华水; 孙建军; 周勇亮; 祖延斌; 田中群; 罗瑾; 林仲华; 谢兆雄; 胡维玲; 胡涌刚; 苏文煅

    2001-01-01

    1 )Brief introduction to microsystems. 2)Discussio ns on the developments of microsystem technologies. 3)Applications of electrochemistry in microsystem: Confined Etchant Layer Technique (CELT) for the complex 3D-pattern micromachining; Focusing Electrophoresis and the application of microsystem in (bio) chemistry (μTAS or Lab on A Chip) ;Smart Electro-Osmosis pump a reasonable choosing for microfluidic network. 4)Concluding remark.%根据田昭武在中国化学会第一届全国纳米技术与应用会议(2000.11.28,厦门)特邀大会报告内容整理而成:1)微系统技术概述(技术的必要性和前景);2)发展微系统技术的特殊困难;3)电化学在微系统技术中的应用,包括用于复杂3D-图形微加工的约束刻蚀剂层技术(CELT);聚焦电泳和微系统在(生物)化学中的应用(μ-TAS或芯片上实验室);芯片实验室中微流体输运网络的合理选择之一-灵巧(Smart)电渗泵;4)结论.

  6. Functionalization of carbon nanotubes with water-insoluble porphyrin in ionic liquid: direct electrochemistry and highly sensitive amperometric biosensing for trichloroacetic acid.

    Science.gov (United States)

    Tu, Wenwen; Lei, Jianping; Ju, Huangxian

    2009-01-01

    A functional composite of single-walled carbon nanotubes (SWNTs) with hematin, a water-insoluble porphyrin, was first prepared in 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]) ionic liquid. The novel composite in ionic liquid was characterized by scanning electron microscopy, ultraviolet absorption spectroscopy, and electrochemical impedance spectroscopy, and showed a pair of direct redox peaks of the Fe(III)/Fe(II) couple. The composite-[BMIM][PF(6)]-modified glassy carbon electrode showed excellent electrocatalytic activity toward the reduction of trichloroacetic acid (TCA) in neutral media due to the synergic effect among SWNTs, [BMIM][PF(6)], and porphyrin, which led to a highly sensitive and stable amperometric biosensor for TCA with a linear range from 9.0x10(-7) to 1.4x10(-4) M. The detection limit was 3.8x10(-7) M at a signal-to-noise ratio of 3. The TCA biosensor had good analytical performance, such as rapid response, good reproducibility, and acceptable accuracy, and could be successfully used for the detection of residual TCA in polluted water. The functional composite in ionic liquid provides a facile way to not only obtain the direct electrochemistry of water-insoluble porphyrin, but also construct novel biosensors for monitoring analytes in real environmental samples.

  7. Applied Control Systems Design

    CERN Document Server

    Mahmoud, Magdi S

    2012-01-01

    Applied Control System Design examines several methods for building up systems models based on real experimental data from typical industrial processes and incorporating system identification techniques. The text takes a comparative approach to the models derived in this way judging their suitability for use in different systems and under different operational circumstances. A broad spectrum of control methods including various forms of filtering, feedback and feedforward control is applied to the models and the guidelines derived from the closed-loop responses are then composed into a concrete self-tested recipe to serve as a check-list for industrial engineers or control designers. System identification and control design are given equal weight in model derivation and testing to reflect their equality of importance in the proper design and optimization of high-performance control systems. Readers’ assimilation of the material discussed is assisted by the provision of problems and examples. Most of these e...

  8. Applied longitudinal analysis

    CERN Document Server

    Fitzmaurice, Garrett M; Ware, James H

    2012-01-01

    Praise for the First Edition "". . . [this book] should be on the shelf of everyone interested in . . . longitudinal data analysis.""-Journal of the American Statistical Association   Features newly developed topics and applications of the analysis of longitudinal data Applied Longitudinal Analysis, Second Edition presents modern methods for analyzing data from longitudinal studies and now features the latest state-of-the-art techniques. The book emphasizes practical, rather than theoretical, aspects of methods for the analysis of diverse types of lo

  9. Applied statistics for economists

    CERN Document Server

    Lewis, Margaret

    2012-01-01

    This book is an undergraduate text that introduces students to commonly-used statistical methods in economics. Using examples based on contemporary economic issues and readily-available data, it not only explains the mechanics of the various methods, it also guides students to connect statistical results to detailed economic interpretations. Because the goal is for students to be able to apply the statistical methods presented, online sources for economic data and directions for performing each task in Excel are also included.

  10. Applied Economics in Teaching

    Institute of Scientific and Technical Information of China (English)

    朱红萍

    2009-01-01

    This paper explains some plain phenomena in teaching and class management with an economic view. Some basic economic principles mentioned therein are: everything has its opportunity cost; the marginal utility of consumption of any kind is diminishing; Game theory is everywhere. By applying the economic theories to teaching, it is of great help for teachers to understand the students' behavior and thus improve the teaching effectiveness and efficiency.

  11. Methods of applied mathematics

    CERN Document Server

    Hildebrand, Francis B

    1992-01-01

    This invaluable book offers engineers and physicists working knowledge of a number of mathematical facts and techniques not commonly treated in courses in advanced calculus, but nevertheless extremely useful when applied to typical problems in many different fields. It deals principally with linear algebraic equations, quadratic and Hermitian forms, operations with vectors and matrices, the calculus of variations, and the formulations and theory of linear integral equations. Annotated problems and exercises accompany each chapter.

  12. Applied ALARA techniques

    Energy Technology Data Exchange (ETDEWEB)

    Waggoner, L.O.

    1998-02-05

    The presentation focuses on some of the time-proven and new technologies being used to accomplish radiological work. These techniques can be applied at nuclear facilities to reduce radiation doses and protect the environment. The last reactor plants and processing facilities were shutdown and Hanford was given a new mission to put the facilities in a safe condition, decontaminate, and prepare them for decommissioning. The skills that were necessary to operate these facilities were different than the skills needed today to clean up Hanford. Workers were not familiar with many of the tools, equipment, and materials needed to accomplish:the new mission, which includes clean up of contaminated areas in and around all the facilities, recovery of reactor fuel from spent fuel pools, and the removal of millions of gallons of highly radioactive waste from 177 underground tanks. In addition, this work has to be done with a reduced number of workers and a smaller budget. At Hanford, facilities contain a myriad of radioactive isotopes that are 2048 located inside plant systems, underground tanks, and the soil. As cleanup work at Hanford began, it became obvious early that in order to get workers to apply ALARA and use hew tools and equipment to accomplish the radiological work it was necessary to plan the work in advance and get radiological control and/or ALARA committee personnel involved early in the planning process. Emphasis was placed on applying,ALARA techniques to reduce dose, limit contamination spread and minimize the amount of radioactive waste generated. Progress on the cleanup has,b6en steady and Hanford workers have learned to use different types of engineered controls and ALARA techniques to perform radiological work. The purpose of this presentation is to share the lessons learned on how Hanford is accomplishing radiological work.

  13. Applied linear regression

    CERN Document Server

    Weisberg, Sanford

    2005-01-01

    Master linear regression techniques with a new edition of a classic text Reviews of the Second Edition: ""I found it enjoyable reading and so full of interesting material that even the well-informed reader will probably find something new . . . a necessity for all of those who do linear regression."" -Technometrics, February 1987 ""Overall, I feel that the book is a valuable addition to the now considerable list of texts on applied linear regression. It should be a strong contender as the leading text for a first serious course in regression analysis."" -American Scientist, May-June 1987

  14. SIFT applied to CBIR

    Directory of Open Access Journals (Sweden)

    ALMEIDA, J.

    2009-12-01

    Full Text Available Content-Based Image Retrieval (CBIR is a challenging task. Common approaches use only low-level features. Notwithstanding, such CBIR solutions fail on capturing some local features representing the details and nuances of scenes. Many techniques in image processing and computer vision can capture these scene semantics. Among them, the Scale Invariant Features Transform~(SIFT has been widely used in a lot of applications. This approach relies on the choice of several parameters which directly impact its effectiveness when applied to retrieve images. In this paper, we discuss the results obtained in several experiments proposed to evaluate the application of the SIFT in CBIR tasks.

  15. Applying Popper's Probability

    CERN Document Server

    Whiting, Alan B

    2014-01-01

    Professor Sir Karl Popper (1902-1994) was one of the most influential philosophers of science of the twentieth century, best known for his doctrine of falsifiability. His axiomatic formulation of probability, however, is unknown to current scientists, though it is championed by several current philosophers of science as superior to the familiar version. Applying his system to problems identified by himself and his supporters, it is shown that it does not have some features he intended and does not solve the problems they have identified.

  16. Applied energy an introduction

    CERN Document Server

    Abdullah, Mohammad Omar

    2012-01-01

    Introduction to Applied EnergyGeneral IntroductionEnergy and Power BasicsEnergy EquationEnergy Generation SystemsEnergy Storage and MethodsEnergy Efficiencies and LossesEnergy industry and Energy Applications in Small -Medium Enterprises (SME) industriesEnergy IndustryEnergy-Intensive industryEnergy Applications in SME Energy industriesEnergy Sources and SupplyEnergy SourcesEnergy Supply and Energy DemandEnergy Flow Visualization and Sankey DiagramEnergy Management and AnalysisEnergy AuditsEnergy Use and Fuel Consumption StudyEnergy Life-Cycle AnalysisEnergy and EnvironmentEnergy Pollutants, S

  17. Applied linear regression

    CERN Document Server

    Weisberg, Sanford

    2013-01-01

    Praise for the Third Edition ""...this is an excellent book which could easily be used as a course text...""-International Statistical Institute The Fourth Edition of Applied Linear Regression provides a thorough update of the basic theory and methodology of linear regression modeling. Demonstrating the practical applications of linear regression analysis techniques, the Fourth Edition uses interesting, real-world exercises and examples. Stressing central concepts such as model building, understanding parameters, assessing fit and reliability, and drawing conclusions, the new edition illus

  18. Applied impulsive mathematical models

    CERN Document Server

    Stamova, Ivanka

    2016-01-01

    Using the theory of impulsive differential equations, this book focuses on mathematical models which reflect current research in biology, population dynamics, neural networks and economics. The authors provide the basic background from the fundamental theory and give a systematic exposition of recent results related to the qualitative analysis of impulsive mathematical models. Consisting of six chapters, the book presents many applicable techniques, making them available in a single source easily accessible to researchers interested in mathematical models and their applications. Serving as a valuable reference, this text is addressed to a wide audience of professionals, including mathematicians, applied researchers and practitioners.

  19. Applied Semantic Web Technologies

    CERN Document Server

    Sugumaran, Vijayan

    2011-01-01

    The rapid advancement of semantic web technologies, along with the fact that they are at various levels of maturity, has left many practitioners confused about the current state of these technologies. Focusing on the most mature technologies, Applied Semantic Web Technologies integrates theory with case studies to illustrate the history, current state, and future direction of the semantic web. It maintains an emphasis on real-world applications and examines the technical and practical issues related to the use of semantic technologies in intelligent information management. The book starts with

  20. Applied Chaos Control

    Science.gov (United States)

    Spano, Mark

    1997-04-01

    The publication by Ott, Grebogi and Yorke(E. Ott, C. Grebogi and J. A. Yorke, Phys. Rev. Lett. 64, 1196 (1990).) of their theory of chaos control in 1990 led to an explosion of experimental work applying their theory to mechanical systems and electronic circuits, lasers and chemical reactors, and heart and brain tissue, to name only a few. In this talk the basics of chaos control as implemented in a simple mechanical system will be described, as well as extensions of the method to biological applications. Finally, current advances in the field, including the maintenance of chaos and the control of high dimensional chaos, will be discussed.

  1. Applied complex variables

    CERN Document Server

    Dettman, John W

    1965-01-01

    Analytic function theory is a traditional subject going back to Cauchy and Riemann in the 19th century. Once the exclusive province of advanced mathematics students, its applications have proven vital to today's physicists and engineers. In this highly regarded work, Professor John W. Dettman offers a clear, well-organized overview of the subject and various applications - making the often-perplexing study of analytic functions of complex variables more accessible to a wider audience. The first half of Applied Complex Variables, designed for sequential study, is a step-by-step treatment of fun

  2. Applied logistic regression

    CERN Document Server

    Hosmer, David W; Sturdivant, Rodney X

    2013-01-01

     A new edition of the definitive guide to logistic regression modeling for health science and other applications This thoroughly expanded Third Edition provides an easily accessible introduction to the logistic regression (LR) model and highlights the power of this model by examining the relationship between a dichotomous outcome and a set of covariables. Applied Logistic Regression, Third Edition emphasizes applications in the health sciences and handpicks topics that best suit the use of modern statistical software. The book provides readers with state-of-

  3. Applied Impact Physics Research

    Science.gov (United States)

    Wickert, Matthias

    2013-06-01

    Applied impact physics research is based on the capability to examine impact processes for a wide range of impact conditions with respect to velocity as well as mass and shape of the projectile. For this reason, Fraunhofer EMI operates a large variety of launchers that address velocities up to ordnance velocities as single stage powder gun but which can also be operated as two-stage light gas guns achieving the regime of low earth orbital velocity. Thereby for projectile masses of up to 100 g hypervelocity impact phenomena up to 7.8 km/s can be addressed. Advanced optical diagnostic techniques like microsecond video are used as commercial systems but - since impact phenomena are mostly related with debris or dust - specialized diagnostics are developed in-house like x-ray cinematography and x-ray tomography. Selected topics of the field of applied impact physics will be presented like the interesting behavior of long rods penetrating low-density materials or experimental findings at hypervelocity for this class of materials as well as new x-ray diagnositic techniques.

  4. Electrochemistry, a technique to prepare redox nano-structured composite materials (polymer/nano-particles) - Characterizations - Applications; L'electrochimie, un outil pour elaborer des materiaux composites redox nanostructures (polymere/nanoparticules) - Caracterisations - Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chardon-Noblat, S. [Grenoble-1 Univ. Joseph Fourier, Lab. d' Electrochimie Organique et de Photochimie Redox, UMR 5630, Institut de Chimie Moleculaire de Grenoble, FR CNRS 2607, 38 - Grenoble (France)

    2006-07-01

    In this work is presented at first the preparation by an electrochemical way of bi functional nano-structured composite materials. It is shown that with the pulsed electrolysis techniques, it is possible to obtain metallic particles whose size and organization are controlled at the nano-scopic scale in redox matrices. Then, are presented the physico-chemical characterizations of these nano-objects (coupled in situ or ex situ at the electrochemistry). The first results relative to the catalytic activation of CO{sub 2} with these materials used as composite cathodes are indicated. (O.M.)

  5. Applied partial differential equations

    CERN Document Server

    Logan, J David

    2015-01-01

    This text presents the standard material usually covered in a one-semester, undergraduate course on boundary value problems and PDEs.  Emphasis is placed on motivation, concepts, methods, and interpretation, rather than on formal theory. The concise treatment of the subject is maintained in this third edition covering all the major ideas: the wave equation, the diffusion equation, the Laplace equation, and the advection equation on bounded and unbounded domains. Methods include eigenfunction expansions, integral transforms, and characteristics. In this third edition, text remains intimately tied to applications in heat transfer, wave motion, biological systems, and a variety other topics in pure and applied science. The text offers flexibility to instructors who, for example, may wish to insert topics from biology or numerical methods at any time in the course. The exposition is presented in a friendly, easy-to-read, style, with mathematical ideas motivated from physical problems. Many exercises and worked e...

  6. Applied number theory

    CERN Document Server

    Niederreiter, Harald

    2015-01-01

    This textbook effectively builds a bridge from basic number theory to recent advances in applied number theory. It presents the first unified account of the four major areas of application where number theory plays a fundamental role, namely cryptography, coding theory, quasi-Monte Carlo methods, and pseudorandom number generation, allowing the authors to delineate the manifold links and interrelations between these areas.  Number theory, which Carl-Friedrich Gauss famously dubbed the queen of mathematics, has always been considered a very beautiful field of mathematics, producing lovely results and elegant proofs. While only very few real-life applications were known in the past, today number theory can be found in everyday life: in supermarket bar code scanners, in our cars’ GPS systems, in online banking, etc.  Starting with a brief introductory course on number theory in Chapter 1, which makes the book more accessible for undergraduates, the authors describe the four main application areas in Chapters...

  7. Applied statistical thermodynamics

    CERN Document Server

    Lucas, Klaus

    1991-01-01

    The book guides the reader from the foundations of statisti- cal thermodynamics including the theory of intermolecular forces to modern computer-aided applications in chemical en- gineering and physical chemistry. The approach is new. The foundations of quantum and statistical mechanics are presen- ted in a simple way and their applications to the prediction of fluid phase behavior of real systems are demonstrated. A particular effort is made to introduce the reader to expli- cit formulations of intermolecular interaction models and to show how these models influence the properties of fluid sy- stems. The established methods of statistical mechanics - computer simulation, perturbation theory, and numerical in- tegration - are discussed in a style appropriate for newcom- ers and are extensively applied. Numerous worked examples illustrate how practical calculations should be carried out.

  8. Applied mechanics of solids

    CERN Document Server

    Bower, Allan F

    2009-01-01

    Modern computer simulations make stress analysis easy. As they continue to replace classical mathematical methods of analysis, these software programs require users to have a solid understanding of the fundamental principles on which they are based. Develop Intuitive Ability to Identify and Avoid Physically Meaningless Predictions Applied Mechanics of Solids is a powerful tool for understanding how to take advantage of these revolutionary computer advances in the field of solid mechanics. Beginning with a description of the physical and mathematical laws that govern deformation in solids, the text presents modern constitutive equations, as well as analytical and computational methods of stress analysis and fracture mechanics. It also addresses the nonlinear theory of deformable rods, membranes, plates, and shells, and solutions to important boundary and initial value problems in solid mechanics. The author uses the step-by-step manner of a blackboard lecture to explain problem solving methods, often providing...

  9. Applied multivariate statistical analysis

    CERN Document Server

    Härdle, Wolfgang Karl

    2015-01-01

    Focusing on high-dimensional applications, this 4th edition presents the tools and concepts used in multivariate data analysis in a style that is also accessible for non-mathematicians and practitioners.  It surveys the basic principles and emphasizes both exploratory and inferential statistics; a new chapter on Variable Selection (Lasso, SCAD and Elastic Net) has also been added.  All chapters include practical exercises that highlight applications in different multivariate data analysis fields: in quantitative financial studies, where the joint dynamics of assets are observed; in medicine, where recorded observations of subjects in different locations form the basis for reliable diagnoses and medication; and in quantitative marketing, where consumers’ preferences are collected in order to construct models of consumer behavior.  All of these examples involve high to ultra-high dimensions and represent a number of major fields in big data analysis. The fourth edition of this book on Applied Multivariate ...

  10. Syntheses, Structures, and Electrochemistry of the Defective ccp [Pt33(CO)38](2-) and the bcc [Pt40(CO)40](6-) Molecular Nanoclusters.

    Science.gov (United States)

    Cattabriga, Enrico; Ciabatti, Iacopo; Femoni, Cristina; Funaioli, Tiziana; Iapalucci, Maria Carmela; Zacchini, Stefano

    2016-06-20

    The molecular [Pt33(CO)38](2-) nanocluster was obtained from the thermal decomposition of Na2[Pt15(CO)30] in methanol. The reaction of [Pt19(CO)22](4-) with acids (1-2 equiv) affords the unstable [Pt19(CO)22](3-) trianion, which evolves with time leading eventually to the [Pt40(CO)40](6-) hexa-anion. The total structures of both nanoclusters were determined via single-crystal X-ray diffraction. [Pt33(CO)38](2-) displays a defective ccp Pt33 core and shows that localized deformations occur in correspondence of atomic defects to "repair" them. In contrast, [Pt40(CO)40](6-) shows a bcc Pt40 core and represents the largest Pt cluster with a body-centered structure. The rich electrochemistry of the two high-nuclearity platinum carbonyl clusters was studied by cyclic voltammetry and electrochemical in situ Fourier transform infrared spectroscopy. The redox changes of [Pt33(CO)38](2-) show features of chemical reversibility and electrochemical quasi-reversibility, and the vibrational spectra in the CO stretching region of the nine redox forms of the cluster [Pt33(CO)38](n) (n = 0 to -4, -6 to -9) are reported. Almost all the redox processes exhibited by [Pt40(CO)40](6-) are chemically and electrochemically reversible, and the eight oxidation states of [Pt40(CO)40] from -4 to -11 were spectroscopically characterized. The effect of the more regular bcc Pt-carbonyl cluster structure of [Pt40(CO)40](6-) with respect to that of the defective ccp Pt33 core on the redox behavior is discussed.

  11. Surface analysis and electrochemistry of a robust carbon-nanofiber-based electrode platform H{sub 2}O{sub 2} sensor

    Energy Technology Data Exchange (ETDEWEB)

    Suazo-Dávila, D.; Rivera-Meléndez, J. [NASA-MIRO Center for Advanced Nanoscale Materials (CANM), Department of Chemistry, Molecular Sciences Research Center, University of Puerto Rico, Río Piedras Campus, San Juan, PR, 00936 (United States); Koehne, J.; Meyyappan, M. [Center for Nanotechnology, NASA Ames Research Center, Moffett Field, CA 94035 (United States); Cabrera, C.R., E-mail: carlos.cabrera2@upr.edu [NASA-MIRO Center for Advanced Nanoscale Materials (CANM), Department of Chemistry, Molecular Sciences Research Center, University of Puerto Rico, Río Piedras Campus, San Juan, PR, 00936 (United States)

    2016-10-30

    Highlights: • Vertically aligned carbon nanofibers were intercalated with SiO{sub 2} for mechanical strength and isolation of individual electrodes. • Stable and robust electrochemical hydrogen peroxide sensor is stable and robust. • Five consecutive calibration curves were done with different hydrogen peroxide concentrations over a period of 3 days without any deterioration in the electrochemical response. • The sensor was also used for the measurement of hydrogen peroxide as one of the by-products of the reaction of cholesterol oxidase with cholesterol and the sensor response exhibited linear behavior from 50 μM to 1 mM in cholesterol concentration. • In general, the electrochemical sensor is robust, stable, and reproducible, and the detection limit and sensitivity responses were among the best when compared with the literature. - Abstract: A vertically aligned carbon nanofiber-based (VACNF) electrode platform was developed for an enzymeless hydrogen peroxide sensor. Vertical nanofibers have heights on the order of 2–3 μm, and diameters that vary from 50 to 100 nm as seen by atomic force microscopy. The VACNF was grown as individual, vertically, and freestanding structures using plasma-enhanced chemical vapor deposition. The electrochemical sensor, for the hydrogen peroxide measurement in solution, showed stability and reproducibility in five consecutive calibration curves with different hydrogen peroxide concentrations over a period of 3 days. The detection limit was 66 μM. The sensitivity for hydrogen peroxide electrochemical detection was 0.0906 mA cm{sup −2} mM{sup −1}, respectively. The sensor was also used for the measurement of hydrogen peroxide as the by-product of the reaction of cholesterol with cholesterol oxidase as a biosensor application. The sensor exhibits linear behavior in the range of 50 μM–1 mM in cholesterol concentrations. The surface analysis and electrochemistry characterization is presented.

  12. The Development of Microsystems and New Applications of Electrochemistry%微系统科技的发展及电化学的新应用

    Institute of Scientific and Technical Information of China (English)

    田昭武; 林华水; 孙建军; 周勇亮; 祖延斌; 田中群; 罗瑾; 林仲华; 谢兆雄; 胡维玲; 胡涌刚; 苏文煅

    2001-01-01

    本文根据田昭武在中国化学会第一届全国纳米技术与应用会议(2000.11.28,厦门)特邀大会报告内容整理而成:   1 微系统技术概述(技术的必要性和前景)   2 发展微系统技术的特殊困难   3 电化学在微系统技术中的应用    3.1 用于复杂3D-图形微加工的约束刻蚀剂层技术(CELT)    3.2 聚焦电泳和微系统在(生物)化学中的应用(μ-TAS或芯片上实验室)    3.3 芯片实验室中微流体输运网络的合理选择之一-灵巧(Smart)电渗泵   4 结论%1 Brief introduction to microsystems   2 Discussions on the developments of microsystem technologies   3 Applications of electrochemistry in microsystem    3.1 Confined Etchant Layer Technique (CELT) for the complex 3D-pattern micromachining    3.2 Focusing Electrophoresis and the application of microsystem in (bio) chemistry (μTAS or Lab on A Chip)    3.3 Smart Electro-Osmosis pump——a reasonable choosing for microfluidic network   4 Concluding remark

  13. Al3+-directed self-assembly and their electrochemistry properties of three-dimensional dendriform horseradish peroxidase/polyacrylamide/platinum/single-walled carbon nanotube composite film.

    Science.gov (United States)

    Xie, Jingsi; Feng, Xiumei; Hu, Jianqiang; Chen, Xiaohua; Li, Aiqing

    2010-01-15

    A novel general methodology for protein immobilization and third-generation biosensor construction is demonstrated, which involves Al(3+)-directed polyacrylamide (PAM) self-assembly into an ordered dendriform structure, easily immobilizing enzymes and nanoparticles. Platinum/single-walled carbon nanotube (Pt/SWCNT) heterojunction nanomaterials were for the first time fabricated via an EDTA-directed synthesis strategy. The Pt/SWCNTs were employed as a supporting matrix to explore a novel immobilization and biosensing platform of redox proteins through cooperating Al(3+)-directed PAM self-assembly. Compared with the almost single-layer horseradish peroxidase (HRP)/PAM film electrode, multilayer HRP/PAM/Pt/SWCNT film electrode exhibited a pair of much stronger redox peaks at -0.22 V (vs. Ag/AgCl). Moreover, with advantages of the ordered multilayer HRP/PAM/Pt/SWCNT film, facilitated direct electron transfer of the metalloenzymes with an apparent heterogeneous electron transfer rate constant (k(s)) of 14.94+/-1.36 s(-1) and smaller peak-to-peak separation (DeltaE(p)) of about 37 mV was acquired on the PAM/Pt/SWCNT-based enzyme electrode. The PAM/Pt/SWCNT-based biosensor demonstrated significant electrocatalytic activity for the reduction of hydrogen peroxide with a small apparent Michaelis-Menten constant (87 microM), wide linear range (1-270 microM), very low detection limit (0.08 microM, S/N=3), and high sensitivity (372 mA cm(-2) M(-1)). Together, these indicated that the Al(3+)-directed HRP/PAM/Pt/SWCNT film was one of ideal candidate materials for direct electrochemistry of redox proteins and the construction of the related enzyme biosensors, and may find potential applications in biomedical, food, and environmental analysis and detection.

  14. Superficial characterization and zircaloy-2 electrochemistry with hydrothermal deposit of platinum; Caracterizacion superficial y electroquimica de zircaloy-2 con deposito hidrotermal de platino

    Energy Technology Data Exchange (ETDEWEB)

    Contreras R, A.; Arganis J, C. R.; Medina A, A. L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Gris C, M. M., E-mail: aida.contreras@inin.gob.mx [Comision Federal de Electricidad, Central Nucleoelectrica Laguna Verde, Carretera Cardel-Nautla Km 42.5, Alto Lucero, Veracruz (Mexico)

    2011-11-15

    The combustible elements of the boiling water nuclear reactors (BWR) are formed by zircaloy-2 tubes that contain in their interior UO{sub 2} pellets. With the objective of mitigating the speed of crack growth by IGSCC to a minimum negative impact on the BWR operation, General Electric developed the noble metals chemical addition (NMCA), in where noble metals particles as Pt, Pd, and Rh, are deposited on the surface of the metal to catalyze the recombination of H{sub 2} and O{sub 2}. Hydrogen is also injected to have it in excess and to favor this recombination (HWC) and zinc to reduce dose. In this work was oxidized zircaloy-2 low similar conditions to the HWC, platinum was deposited starting from a solution of Na{sub 2}Pt(OH){sub 6} with 30 ppm of Pt, in refined samples and without polishing, they were characterized by scanning electron microscopy, energy dispersed spectroscopy, XPS and electrochemistry, by means of Tafel curves and cyclical polarization. On the zircaloy surface was found a ZrO{sub 2} layer that remains under the different study conditions. Under HWC conditions is the oxides formation, possibly complex oxides of zirconium, iron and tin. After the platinum deposit these oxides decrease forming the sub-oxides: Zr{sub 2}O, Zr O, Zr{sub 2}O{sub 3}. The Tafel curves indicates the reduction of the oxygen of the sample with platinum and the cyclical polarization curves show that the reactions that happen on the zircaloy electrodes are not dur to located corrosion. (Author)

  15. Amperometric carbohydrate antigen 19-9 immunosensor based on three dimensional ordered macroporous magnetic Au film coupling direct electrochemistry of horseradish peroxidase

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qi [College of Sciences, Nanjing Tech University, Nanjing 211816 (China); Chen, Xiaojun, E-mail: chenxj_njut@126.com [College of Sciences, Nanjing Tech University, Nanjing 211816 (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Tang, Yin [Zhangjiagang Hospital of Traditional Chinese Medicine, Zhangjiagang 215600 (China); Ge, Lingna; Guo, Buhua [College of Sciences, Nanjing Tech University, Nanjing 211816 (China); Yao, Cheng, E-mail: yaochengnjut@163.com [College of Sciences, Nanjing Tech University, Nanjing 211816 (China)

    2014-03-01

    Highlights: • Three dimensional ordered macroporous magnetic electrode was newly used in electrochemical immunosensor. • The large surface area of macroporous magnetic electrode could improve the immobilized amount of antibody. • Au nanoparticles functionalized SBA-15 was used to immobilize enzyme labeled Ab₂ and enzyme. • Macroporous magnetic electrode and Au nanoparticles composite facilitated the direct electron transfer of enzyme. • The immunoassay avoided adding electron transfer mediator, simplifying the procedure. Abstract: A sandwich-type electrochemical immunosensor for the detection of carbohydrate antigen 19-9 (CA 19-9) antigen based on the immobilization of primary antibody (Ab₁) on three dimensional ordered macroporous magnetic (3DOMM) electrode, and the direct electrochemistry of horseradish peroxidase (HRP) that was used as both the label of secondary antibody (Ab₂) and the blocking reagent. The 3DOMM electrode was fabricated by introducing core–shell Au–SiO₂@Fe₃O₄ nanospheres onto the surface of three dimensional ordered macroporous (3DOM) Au electrode via the application of an external magnet. Au nanoparticles functionalized SBA-15 (Au@SBA-15) was conjugated to the HRP labeled secondary antibody (HRP-Ab₂) through the Au–SH or Au–NH₃⁺ interaction, and HRP was also used as the block reagent. The formation of antigen–antibody complex made the combination of Au@SBA-15 and 3DOMM exhibit remarkable synergistic effects for accelerating direct electron transfer (DET) between HRP and the electrode. Under the optimal conditions, the DET current signal increased proportionally to CA 19-9 concentration in the range of 0.05 to 15.65 U mL⁻¹ with a detection limit of 0.01 U mL⁻¹. Moreover, the immunosensor showed high selectivity, good stability, satisfactory reproducibility and regeneration. Importantly, the developed method was used to assay clinical serum specimens, achieving a good relation with those obtained from

  16. Direct electrochemistry and electrocatalytic properties of hemoglobin immobilized on a carbon ionic liquid electrode modified with mesoporous molecular sieve MCM-41.

    Science.gov (United States)

    Li, Yonghong; Zeng, Xiandong; Liu, Xiaoying; Liu, Xinsheng; Wei, Wanzhi; Luo, Shenglian

    2010-08-01

    The direct electron transfer and electrocatalysis of hemoglobin (Hb) entrapped in the MCM-41 modified carbon ionic liquid electrode (CILE) were investigated by using cyclic voltammetry in 0.10 M pH 7.0 phosphate buffer solution (PBS). Due to its uniform pore structure, high surface areas and good biocompatibility, the mesoporous silica sieve MCM-41 provided a suitable matrix for immobilization of biomolecule. The MCM-41 modified CILE showed significant promotion to the direct electron transfer of Hb, which exhibited a pair of well defined and quasi-reversible peaks for heme Fe(III)/Fe(II) with a formal potential of -0.284 V (vs. Ag/AgCl). Additionally, the Hb immobilized on the MCM-41 modified carbon ionic liquid electrode showed excellent electrocatalytic activity toward H(2)O(2). The electrocatalytic current values were linear with increasing concentration of H(2)O(2) in a wide range of 5-310 microM and the corresponding detection limit was calculated to be 5 x 10(-8)M (S/N=3). The surface coverage of Hb immobilized on the MCM-41 modified carbon ionic liquid electrode was about 2.54 x 10(-9) molcm(-2). The Michaelis-Menten constant K(m)(app) of 214 microM indicated that the Hb immobilized on the modified electrode showed high affinity to H(2)O(2). The proposed electrode had high stability and good reproducibility due to the protection effect of MCM-41 and ionic liquid, and it would have wide potential applications in direct electrochemistry, biosensors and biocatalysis.

  17. Structural, spectral, electrochemistry, thermal properties and theoretical studies on 4-[N, N-di(4-tolyl)amino] benzaldehyde-2-chloro benzoylhydrazone

    Science.gov (United States)

    Lizeng, Liu; Wei, Li; Xianfang, Meng; Dongzhi, Liu; Gongfeng, Xu; Zhengchen, Bai

    2014-11-01

    The title compound 4-[N, N-di(4-tolyl)amino] benzaldehyde-2-chloro benzoylhydrazone (C28H24ClN3O, Mr = 453.96) was synthesized by the reaction of 4-[N, N-di(4-tolyl)amino] benzaldehyde with 2-chlorobenzohydrazide, and its structure was characterized by IR, 1H NMR, 13H NMR, high-resolution mass spectrometry and single-crystal X-ray diffraction. The crystal belongs to Monoclinic, space group P2(1)/n with a = 12.626(3), b = 12.609(3), c = 15.837(3) Å, β = 90.00(3)°, Z = 5, V = 2512.5(9) Å3, Mr = 453.95, Dc = 1.280 g/cm3, μ = 0.183 mm-1, F(0 0 0) = 1024, R = 0.0432 and wR = 0.1087. X-ray analysis revealed that one of the benzene ring and acylhydrazone were essentially planar, the 2-chloro benzene ring and amide were non-planar, the torsion angles C(1)sbnd C(6)sbnd C(7)sbnd O(1) and C(5)sbnd C(6)sbnd C(7)sbnd O(1) are 61.4(5)° and -114.4(4)°. The thermal stability studies indicate that the title compound is stable up to 341.1 °C. The spectral, electrochemistry properties and theoretical studies show that the title compound is a good candidate for the charge-transporting materials.

  18. Applied Linguistics and the "Annual Review of Applied Linguistics."

    Science.gov (United States)

    Kaplan, Robert B.; Grabe, William

    2000-01-01

    Examines the complexities and differences involved in granting disciplinary status to the role of applied linguistics, discusses the role of the "Annual Review of Applied Linguistics" as a contributor to the development of applied linguistics, and highlights a set of publications for the future of applied linguistics. (Author/VWL)

  19. Applied hydraulic transients

    CERN Document Server

    Chaudhry, M Hanif

    2014-01-01

    This book covers hydraulic transients in a comprehensive and systematic manner from introduction to advanced level and presents various methods of analysis for computer solution. The field of application of the book is very broad and diverse and covers areas such as hydroelectric projects, pumped storage schemes, water-supply systems, cooling-water systems, oil pipelines and industrial piping systems. Strong emphasis is given to practical applications, including several case studies, problems of applied nature, and design criteria. This will help design engineers and introduce students to real-life projects. This book also: ·         Presents modern methods of analysis suitable for computer analysis, such as the method of characteristics, explicit and implicit finite-difference methods and matrix methods ·         Includes case studies of actual projects ·         Provides extensive and complete treatment of governed hydraulic turbines ·         Presents design charts, desi...

  20. Academic training: Applied superconductivity

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 17, 18, 19 January from 11.00 to 12.00 hrs Council Room, Bldg 503 Applied Superconductivity : Theory, superconducting Materials and applications E. PALMIERI/INFN, Padova, Italy When hearing about persistent currents recirculating for several years in a superconducting loop without any appreciable decay, one realizes that we are dealing with a phenomenon which in nature is the closest known to the perpetual motion. Zero resistivity and perfect diamagnetism in Mercury at 4.2 K, the breakthrough during 75 years of several hundreds of superconducting materials, the revolution of the "liquid Nitrogen superconductivity"; the discovery of still a binary compound becoming superconducting at 40 K and the subsequent re-exploration of the already known superconducting materials: Nature discloses drop by drop its intimate secrets and nobody can exclude that the last final surprise must still come. After an overview of phenomenology and basic theory of superconductivity, the lectures for this a...

  1. Applying evolutionary anthropology.

    Science.gov (United States)

    Gibson, Mhairi A; Lawson, David W

    2015-01-01

    Evolutionary anthropology provides a powerful theoretical framework for understanding how both current environments and legacies of past selection shape human behavioral diversity. This integrative and pluralistic field, combining ethnographic, demographic, and sociological methods, has provided new insights into the ultimate forces and proximate pathways that guide human adaptation and variation. Here, we present the argument that evolutionary anthropological studies of human behavior also hold great, largely untapped, potential to guide the design, implementation, and evaluation of social and public health policy. Focusing on the key anthropological themes of reproduction, production, and distribution we highlight classic and recent research demonstrating the value of an evolutionary perspective to improving human well-being. The challenge now comes in transforming relevance into action and, for that, evolutionary behavioral anthropologists will need to forge deeper connections with other applied social scientists and policy-makers. We are hopeful that these developments are underway and that, with the current tide of enthusiasm for evidence-based approaches to policy, evolutionary anthropology is well positioned to make a strong contribution.

  2. Applied Historical Astronomy

    Science.gov (United States)

    Stephenson, F. Richard

    2014-01-01

    F. Richard Stephenson has spent most of his research career -- spanning more than 45 years -- studying various aspects of Applied Historical Astronomy. The aim of this interdisciplinary subject is the application of historical astronomical records to the investigation of problems in modern astronomy and geophysics. Stephenson has almost exclusively concentrated on pre-telescopic records, especially those preserved from ancient and medieval times -- the earliest reliable observations dating from around 700 BC. The records which have mainly interested him are of eclipses (both solar and lunar), supernovae, sunspots and aurorae, and Halley's Comet. The main sources of early astronomical data are fourfold: records from ancient and medieval East Asia (China, together with Korea and Japan); ancient Babylon; ancient and medieval Europe; and the medieval Arab world. A feature of Stephenson's research is the direct consultation of early astronomical texts in their original language -- either working unaided or with the help of colleagues. He has also developed a variety of techniques to help interpret the various observations. Most pre-telescopic observations are very crude by present-day standards. In addition, early motives for skywatching were more often astrological rather than scientific. Despite these drawbacks, ancient and medieval astronomical records have two remarkable advantages over modern data. Firstly, they can enable the investigation of long-term trends (e.g. in the terrestrial rate of rotation), which in the relatively short period covered by telescopic observations are obscured by short-term fluctuations. Secondly, over the lengthy time-scale which they cover, significant numbers of very rare events (such as Galactic supernovae) were reported, which have few -- if any-- counterparts in the telescopic record. In his various researches, Stephenson has mainly focused his attention on two specific topics. These are: (i) long-term changes in the Earth's rate of

  3. Vygotsky in applied neuropsychology

    Directory of Open Access Journals (Sweden)

    Glozman J. M.

    2016-12-01

    Full Text Available The aims of this paper are: 1 to show the role of clinical experience for the theoretical contributions of L.S. Vygotsky, and 2 to analyze the development of these theories in contemporary applied neuropsychology. An analysis of disturbances of mental functioning is impossible without a systemic approach to the evidence observed. Therefore, medical psychology is fundamental for forming a systemic approach to psychology. The assessment of neurological patients at the neurological hospital of Moscow University permitted L.S. Vygotsky to create, in collaboration with A.R. Luria, the theory of systemic dynamic localization of higher mental functions and their relationship to cultural conditions. In his studies of patients with Parkinson’s disease, Vygotsky also set out 3 steps of systemic development: interpsychological, then extrapsychological, then intrapsychological. L.S. Vygotsky and A.R. Luria in the late 1920s created a program to compensate for the motor subcortical disturbances in Parkinson’s disease (PD through a cortical (visual mediation of movements. We propose to distinguish the objective mediating factors — like teaching techniques and modalities — from subjective mediating factors, like the individual’s internal representation of his/her own disease. The cultural-historical approach in contemporary neuropsychology forces neuropsychologists to re-analyze and re-interpret the classic neuropsychological syndromes; to develop new assessment procedures more in accordance with the patient’s conditions of life; and to reconsider the concept of the social brain as a social and cultural determinant and regulator of brain functioning. L.S. Vygotsky and A.R. Luria proved that a defect interferes with a child’s appropriation of his/her culture, but cultural means can help the child overcome the defect. In this way, the cultural-historical approach became, and still is, a methodological basis for remedial education.

  4. Essays in applied microeconomics

    Science.gov (United States)

    Wang, Xiaoting

    In this dissertation I use Microeconomic theory to study firms' behavior. Chapter One introduces the motivations and main findings of this dissertation. Chapter Two studies the issue of information provision through advertisement when markets are segmented and consumers' price information is incomplete. Firms compete in prices and advertising strategies for consumers with transportation costs. High advertising costs contribute to market segmentation. Low advertising costs promote price competition among firms and improves consumer welfare. Chapter Three also investigates market power as a result of consumers' switching costs. A potential entrant can offer a new product bundled with an existing product to compensate consumers for their switching cost. If the primary market is competitive, bundling simply plays the role of price discrimination, and it does not dominate unbundled sales in the process of entry. If the entrant has market power in the primary market, then bundling also plays the role of leveraging market power and it dominates unbundled sales. The market for electric power generation has been opened to competition in recent years. Chapter Four looks at issues involved in the deregulated electricity market. By comparing the performance of the competitive market with the social optimum, we identify the conditions under which market equilibrium generates socially efficient levels of electric power. Chapter Two to Four investigate the strategic behavior among firms. Chapter Five studies the interaction between firms and unemployed workers in a frictional labor market. We set up an asymmetric job auction model, where two types of workers apply for two types of job openings by bidding in auctions and firms hire the applicant offering them the most profits. The job auction model internalizes the determination of the share of surplus from a match, therefore endogenously generates incentives for an efficient division of the matching surplus. Microeconomic

  5. Applied large eddy simulation.

    Science.gov (United States)

    Tucker, Paul G; Lardeau, Sylvain

    2009-07-28

    Large eddy simulation (LES) is now seen more and more as a viable alternative to current industrial practice, usually based on problem-specific Reynolds-averaged Navier-Stokes (RANS) methods. Access to detailed flow physics is attractive to industry, especially in an environment in which computer modelling is bound to play an ever increasing role. However, the improvement in accuracy and flow detail has substantial cost. This has so far prevented wider industrial use of LES. The purpose of the applied LES discussion meeting was to address questions regarding what is achievable and what is not, given the current technology and knowledge, for an industrial practitioner who is interested in using LES. The use of LES was explored in an application-centred context between diverse fields. The general flow-governing equation form was explored along with various LES models. The errors occurring in LES were analysed. Also, the hybridization of RANS and LES was considered. The importance of modelling relative to boundary conditions, problem definition and other more mundane aspects were examined. It was to an extent concluded that for LES to make most rapid industrial impact, pragmatic hybrid use of LES, implicit LES and RANS elements will probably be needed. Added to this further, highly industrial sector model parametrizations will be required with clear thought on the key target design parameter(s). The combination of good numerical modelling expertise, a sound understanding of turbulence, along with artistry, pragmatism and the use of recent developments in computer science should dramatically add impetus to the industrial uptake of LES. In the light of the numerous technical challenges that remain it appears that for some time to come LES will have echoes of the high levels of technical knowledge required for safe use of RANS but with much greater fidelity.

  6. Essays in Applied Microeconomics

    Science.gov (United States)

    Ge, Qi

    This dissertation consists of three self-contained applied microeconomics essays on topics related to behavioral economics and industrial organization. Chapter 1 studies how sentiment as a result of sports event outcomes affects consumers' tipping behavior in the presence of social norms. I formulate a model of tipping behavior that captures consumer sentiment following a reference-dependent preference framework and empirically test its relevance using the game outcomes of the NBA and the trip and tipping data on New York City taxicabs. While I find that consumers' tipping behavior responds to unexpected wins and losses of their home team, particularly in close game outcomes, I do not find evidence for loss aversion. Coupled with the findings on default tipping, my empirical results on the asymmetric tipping responses suggest that while social norms may dominate loss aversion, affect and surprises can result in freedom on the upside of tipping. Chapter 2 utilizes a novel data source of airline entry and exit announcements and examines how the incumbent airlines adjust quality provisions as a response to their competitors' announcements and the role of timing in such responses. I find no evidence that the incumbents engage in preemptive actions when facing probable entry and exit threats as signaled by the competitors' announcements in either short term or long term. There is, however, evidence supporting their responses to the competitors' realized entry or exit. My empirical findings underscore the role of timing in determining preemptive actions and suggest that previous studies may have overestimated how the incumbent airlines respond to entry threats. Chapter 3, which is collaborated with Benjamin Ho, investigates the habit formation of consumers' thermostat setting behavior, an often implicitly made decision and yet a key determinant of home energy consumption and expenditures. We utilize a high frequency dataset on household thermostat usage and find that

  7. Direct electrochemistry of horseradish peroxidase immobilized on the layered calcium carbonate-gold nanoparticles inorganic hybrid composite.

    Science.gov (United States)

    Li, Feng; Feng, Yan; Wang, Zhen; Yang, Limin; Zhuo, Linhai; Tang, Bo

    2010-06-15

    A mediator-free hydrogen peroxide (H(2)O(2)) biosensor was fabricated based on immobilization of horseradish peroxidase (HRP) on layered calcium carbonate-gold nanoparticles (CaCO(3)-AuNPs) inorganic hybrid composite. The proposed biosensor showed a strong electrocatalytic activity toward the reduction of H(2)O(2), which could be attributed to the favored orientation of HRP in the well-confined surface as well as the high electrical conductivity of the resulting CaCO(3)-AuNPs inorganic hybrid composite. The hybrid composite was obtained by the adsorption of AuNPs onto the surfaces of layered CaCO(3) through electrostatic interaction. The key analytical parameters relative to the biosensor performance such as pH and applied potential were optimized. The developed biosensor also exhibited a fast amperometric response (3s), a good linear response toward H(2)O(2) over a wide range of concentration from 5.0x10(-7) to 5.2x10(-3)M, and a low detection limit of 1.0x10(-7)M. The facile, inexpensive and reliable sensing platform based on layered CaCO(3)-AuNPs inorganic hybrid composite should hold a huge potential for the fabrication of more other biosensors.

  8. Direct electrochemistry of hemoglobin and biosensing for hydrogen peroxide using a film containing silver nanoparticles and poly(amidoamine) dendrimer

    Energy Technology Data Exchange (ETDEWEB)

    Baccarin, Marina [Nanomedicine and Nanotoxicology Group, Instituto de Física de São Carlos, Universidade de São Paulo, 13566-390 São Carlos, SP (Brazil); Departamento de Química, Universidade Federal de São Carlos, 13565-970 São Carlos, SP (Brazil); Janegitz, Bruno C., E-mail: brunocj@ymail.com [Departamento de Química, Universidade Federal de São Carlos, 13565-970 São Carlos, SP (Brazil); Departamento de Ciências da Natureza, Matemática e Educação, Universidade Federal de São Carlos, 13600-970 Araras, SP (Brazil); Berté, Rodrigo [Nanomedicine and Nanotoxicology Group, Instituto de Física de São Carlos, Universidade de São Paulo, 13566-390 São Carlos, SP (Brazil); Vicentini, Fernando Campanhã [Departamento de Química, Universidade Federal de São Carlos, 13565-970 São Carlos, SP (Brazil); Banks, Craig E. [Faculty of Science and Engineering, School of Chemistry and the Environment, Division of Chemistry and Environmental Science, Manchester Metropolitan University, Chester Street, Manchester M15GD (United Kingdom); Fatibello-Filho, Orlando [Departamento de Química, Universidade Federal de São Carlos, 13565-970 São Carlos, SP (Brazil); and others

    2016-01-01

    A new architecture for a biosensor is proposed using a glassy carbon electrode (GCE) modified with hemoglobin (Hb) and silver nanoparticles (AgNPs) encapsulated in poly(amidoamine) dendrimer (PAMAM). The biosensors were characterized using ultraviolet–visible spectroscopy, ζ-potential and cyclic voltammetry to investigate the interactions between Hb, AgNPs and the PAMAM film. The biosensor exhibited a well-defined cathodic peak attributed to reduction of the Fe{sup 3+} present in the heme group in Hb, as revealed by cyclic voltammetry in the presence of O{sub 2}. An apparent heterogeneous electron transfer rate of 4.1 s{sup −1} was obtained. The Hb–AgNPs-PAMAM/GCE third generation biosensor was applied in the amperometric determination of hydrogen peroxide over the linear range from 6.0 × 10{sup −6} to 9.1 × 10{sup −5} mol L{sup −1} with a detection limit of 4.9 × 10{sup −6} mol L{sup −1}. The proposed method can be extended to immobilize and evaluate the direct electron transfer of other redox enzymes. - Highlights: • A new architecture for biosensor using Hb, AgNPs and PAMAM is proposed. • H{sub 2}O{sub 2} is determined by amperometry using the proposed third generation biosensor. • The direct electron transfer was obtained from Hb using Hb–AgNPs–PAMAM.

  9. Nanocrystalline TiO{sub 2} films containing sulfur and gold: Synthesis, characterization and application to immobilize and direct electrochemistry of cytochrome c

    Energy Technology Data Exchange (ETDEWEB)

    Rafiee-Pour, Hossain-Ali, E-mail: rafieepour@kashanu.ac.ir [Biotechnology Division, Department of Molecular and Cell Biology, Faculty of Chemistry, University of Kashan, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of); Hamadanian, Masood [Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan , Islamic Republic of Iran (Iran, Islamic Republic of); Department of Physical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of); Koushali, Samaneh Katebi [Department of Physical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Islamic Republic of Iran (Iran, Islamic Republic of)

    2016-02-15

    Graphical abstract: - Highlights: • Promoting efficiency of TiO{sub 2} in cyt c immobilization by metal and nonmetal doping. • Synthesis of Au/S-TiO{sub 2} as a novel and efficient for cyt c immobilization. • Investigating structural, chemical and morphological characteristics of prepared TiO{sub 2}, S-TiO{sub 2} and Au/S-TiO{sub 2} nanoparticles. • 4%Au/S-TiO{sub 2} showed high surface area, nanometer size, strong absorbance, high efficiency in cyt c immobilization. • Promoting immobilization efficiency by addition of a small amount of gold at the surface of TiO{sub 2} by photochemistry method. - Abstract: In this paper, nanoporous titanium dioxide (TiO{sub 2}) film was used for cytochrome c (cyt c) immobilization as an electrode substrate for electrochemical redox activity of the adsorbed cyt c. The result of cyclic voltammetry exhibited a pair of well-defined and quasi-reversible peaks for direct electron transfer of cyt c (formal potential [E{sup 0}′ = (E{sub pa} + E{sub pc})/2] of 53 mV versus Ag/AgCl). In addition the effect of metal and nonmetal ions (Au, S) co-doping on the efficiency of TiO{sub 2} nanoparticles (prepared by combining sol–gel and photo-deposition methods) on the cyt c immobilization process was investigated. The results exhibited that the Au, S-co-doped TiO{sub 2} (Au/S-TiO{sub 2}) with a spheroidal shape demonstrates a smaller grain size than the pure TiO{sub 2}. Meanwhile, the UV–vis DRS of Au/S-TiO{sub 2} showed a considerable red shift to the visible region. As a result, it was found that 4% Au/0.1% S-TiO{sub 2} had the highest efficiency for cytochrome c immobilization. The results showed that the peak currents were higher after the annealing of the TiO{sub 2} film. This observation suggests that the use of TiO{sub 2} films may be advantageous for the development of nanoporous biosensors employing reductive electrochemistry.

  10. APPLIED RESEARCH ON HIGHLY BORON-DOPED DIAMOND ELECTRODES IN ELECTROCHEMISTRY%高硼掺杂金刚石膜电极的电化学应用研究

    Institute of Scientific and Technical Information of China (English)

    胡陈果

    2002-01-01

    概述了高硼掺杂金刚石膜电极的电化学研究的最新进展,介绍了高硼掺杂金刚石膜电极的制备、金刚石膜电极在水介质中的电化学行为、金刚石膜电极在废水处理、微量有机化合物成分探测和蜂窝状金刚石电极双电层电容器方面的应用.

  11. Applied Ethics in Nowadays Society

    OpenAIRE

    Tomita CIULEI

    2013-01-01

    This special issue is dedicated to Nowadays Applied Ethics in Society, and falls in the field of social sciences and humanities, being hosted both theoretical approaches and empirical research in various areas of applied ethics. Applied ethics analyzes of a series of morally concrete situations of social or professional practice in order to make / adopt decisions. In the field of applied ethics are integrated medical ethics, legal ethics, media ethics, professional ethics, environmental ethic...

  12. The Routledge Applied Linguistics Reader

    Science.gov (United States)

    Wei, Li, Ed.

    2011-01-01

    "The Routledge Applied Linguistics Reader" is an essential collection of readings for students of Applied Linguistics. Divided into five sections: Language Teaching and Learning, Second Language Acquisition, Applied Linguistics, Identity and Power and Language Use in Professional Contexts, the "Reader" takes a broad…

  13. The Routledge Applied Linguistics Reader

    Science.gov (United States)

    Wei, Li, Ed.

    2011-01-01

    "The Routledge Applied Linguistics Reader" is an essential collection of readings for students of Applied Linguistics. Divided into five sections: Language Teaching and Learning, Second Language Acquisition, Applied Linguistics, Identity and Power and Language Use in Professional Contexts, the "Reader" takes a broad interpretation of the subject…

  14. Applied Ethics in Nowadays Society

    Directory of Open Access Journals (Sweden)

    Tomita CIULEI

    2013-12-01

    Full Text Available This special issue is dedicated to Nowadays Applied Ethics in Society, and falls in the field of social sciences and humanities, being hosted both theoretical approaches and empirical research in various areas of applied ethics. Applied ethics analyzes of a series of morally concrete situations of social or professional practice in order to make / adopt decisions. In the field of applied ethics are integrated medical ethics, legal ethics, media ethics, professional ethics, environmental ethics, business ethics etc. Classification-JEL: A23

  15. Reductive removal of nitrate by electrochemistry/catalytic hydrogenation coupling process: kinetics and mechanism%电化学/催化加氢工艺去除硝酸盐的动力学及机理

    Institute of Scientific and Technical Information of China (English)

    张志强; 徐勇鹏; 时文歆; 张瑞君; 鲍现; 崔福义

    2016-01-01

    为解决地下水硝酸盐(NO3--N)污染问题,采用电化学/催化加氢耦合工艺对其进行去除,重点考察该工艺对NO3--N的降解动力学及反应机理.结果表明,电化学/催化加氢耦合工艺在厌氧条件下能够在短时间内将NO3--N完全去除,去除速率(以N计)可达72.6 mg.L-1.h-1 ,反应符合二级反应动力学规律,常数k=0.005 5 cm2.mA-1.min-1 . 水中NO3--N一部分由电化学反硝化降解去除,另一部分由催化加氢还原去除,两种反应通过电解水产H2反应耦联成为一个整体,宏观上符合电化学反硝化机理.%The kinetics and mechanism in the electrochemistry/catalytic hydrogenation ( E/C ) coupling process, which was employed to remove nitrate ( NO3--N ) from groundwater, was investigated in this paper. The results demonstrated that the NO3--N could be rapidly removed by E/C under anoxic conditions, and the degradation efficiency of NO3--N followed the increasing current density(ID) with observed second order reaction rate and the constant( k ) value of 0. 005 5 cm2·mA-1·min-1 . The NO3--N reductive by E/C with two kinds of reactions, electrochemistry denitrification and catalytic reduction, both of which aggregated by the reaction of brine electrolysis.

  16. Development of the Applied Baccalaureate

    Science.gov (United States)

    Townsend, Barbara K.; Bragg, Debra D.; Ruud, Collin M.

    2009-01-01

    Increasing demands for economic competitiveness and educational effectiveness have led states and institutions to implement new approaches to facilitating baccalaureate completion. This study examined one of these approaches, the applied baccalaureate degree, which is designed to incorporate applied associate course work and degrees once…

  17. Writing, Literacy, and Applied Linguistics.

    Science.gov (United States)

    Leki, Ilona

    2000-01-01

    Discusses writing and literacy in the domain of applied linguistics. Focus is on needs analysis for literacy acquisition; second language learner identity; longitudinal studies as extensions of identity work; and applied linguistics contributions to second language literacy research. (Author/VWL)

  18. Conversation Analysis and Applied Linguistics.

    Science.gov (United States)

    Schegloff, Emanuel A.; Koshik, Irene; Jacoby, Sally; Olsher, David

    2002-01-01

    Offers biographical guidance on several major areas of conversation-analytic work--turn-taking, repair, and word selection--and indicates past or potential points of contact with applied linguistics. Also discusses areas of applied linguistic work. (Author/VWL)

  19. Applied probability and stochastic processes

    CERN Document Server

    Sumita, Ushio

    1999-01-01

    Applied Probability and Stochastic Processes is an edited work written in honor of Julien Keilson. This volume has attracted a host of scholars in applied probability, who have made major contributions to the field, and have written survey and state-of-the-art papers on a variety of applied probability topics, including, but not limited to: perturbation method, time reversible Markov chains, Poisson processes, Brownian techniques, Bayesian probability, optimal quality control, Markov decision processes, random matrices, queueing theory and a variety of applications of stochastic processes. The book has a mixture of theoretical, algorithmic, and application chapters providing examples of the cutting-edge work that Professor Keilson has done or influenced over the course of his highly-productive and energetic career in applied probability and stochastic processes. The book will be of interest to academic researchers, students, and industrial practitioners who seek to use the mathematics of applied probability i...

  20. ELECTROCHEMISTRY OF FUEL CELL ELECTRODES.

    Science.gov (United States)

    optimization of fuel cell electrodes. Hydrogen oxidation and reduction, the reduction of oxygen, and the oxidation of formic acid, a soluble organic...substance, were selected for these studiees because of their relevance to fuel cell systems and because of their relative simplicity. The electrodes

  1. Electrochemistry at the Molecular Level.

    Science.gov (United States)

    1983-12-01

    BENZOTRIAZOLE A -Z M. FLEISCHMANN, I. R. HILL Department or Chemistry, The University, Southampton S09 SNH, U.K. G. MENGOLI and M. M. MUSIANI Istituto di...in alkaline benzotisizole ( BTA ) solutions have been investigated. Addition of benzylamine to the anodizing solution was found to lead to much faster

  2. CHEMISTRY, ELECTROCHEMISTRY, AND ELECTROCHEMICAL APPLICATIONS

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf; Bjerrum, Niels

    2009-01-01

    About 350 Papers Covering: Basics of Electrodes, Electrolytes, Cells, Batteries and Stacks, Measurement Techniques, Synthesis of Materials, Primary Batteries, Secondary Batteries, Supercapacitors, and Fuel Cells, Hydrogen Production and Storage, Photoelectrochemical Cells, Safety, Recycling, Port...

  3. Electrochemistry at Very Small Electrodes

    Science.gov (United States)

    1989-09-30

    properties of low current at high current density and short diffusional relaxation times have been used for applications to corrosion problems. Microelectrode; Voltammetry, Electroanalytical chemistry .

  4. Direct electrochemistry of redox proteins.

    NARCIS (Netherlands)

    Heering, H.A.

    1995-01-01

    The goal of the project was to obtain more detailed insight in interactions between redox proteins and solid electrodes and the mechanisms of electron transfer. In addition to this, the influence of the protein environment on the redox properties of the active site and the possible influence of the

  5. Electrochemistry of Q-graphene.

    Science.gov (United States)

    Randviir, Edward P; Brownson, Dale A C; Gómez-Mingot, Maria; Kampouris, Dimitrios K; Iniesta, Jesús; Banks, Craig E

    2012-10-21

    A newly synthesised type of graphene, Q-Graphene, has been physically and electrochemically characterised with Scanning and Transmission Electron Microscopy (SEM, TEM), X-ray Photoelectron Spectroscopy (XPS) and Cyclic Voltammetry (CV). Interpretation of SEM, TEM and XPS data reveal the material to consist of hollow carbon nanospheres of multi-layer graphene (viz. graphite), which exhibit a total oxygen content of ca. 36.0% (atomic weight via XPS). In addition to the carbon structures present, spherical magnesium oxide particles of ≤50 nm in diameter are abundantly present in the sample (ca. 16.2%). Interestingly, although the TEM/SEM images show macroporous carbon structures, Raman spectroscopy shows peaks typically characteristic of graphene, which suggests the material is highly heterogeneous and consists of many types of carbon allotropes. Q-Graphene is electrochemically characterised using both inner-sphere and outer-sphere electrochemical redox probes, namely potassium ferrocyanide(II), hexaammine-ruthenium(III) chloride and hexachloroiridate(III), in addition to the biologically relevant and electroactive analytes, norepinephrine, β-nicotinamide adenine dinucleotide (NADH) and l-ascorbic acid. The electrochemical response of Q-Graphene is benchmarked against edge plane- and basal plane-pyrolytic graphite (EPPG and BPPG respectively), pristine graphene and graphite alternatives. Q-Graphene is found to exhibit fast electron transfer kinetics, likely due to its high proportion of folded edges and surface defects, exhibiting a response similar to that of EPPG - which exhibits fast electron transfer rates due to the high proportion of edge plane sites it possesses. Furthermore, we demonstrate that the specific oxygen content plays a pivotal role in dictating the observed electrochemical response, which is analyte dependant. Consequently there is potential for this new member of the graphene family to be beneficially utilised in various electrochemical applications.

  6. Applications of ultrasound in electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Silva Martinez, Susana

    1997-10-01

    The effect of the ultrasound on electrochemical processes has been investigated employing a microelectrode within the cavitating media. Transient mass transport was strongly enhanced in the presence of ultrasound. High rates of mass transfer of up to 1.5 cm s-1 were observed. These high rates of mass transfer were attributed to two cavitation processes. First, bubble collapse at or near the solid-liquid interface with the consequent formation of a high speed liquid microjet directed at the electrode surface. Second, bubble motion near or within the diffusion layer or the electrode. Single current transients were also recorded at high time resolution. These single current transients were attributed to the short-time perturbation of the diffusion field of the microelectrode due to impacts of cavitation bubble collapse followed by a long time relaxation of the diffusion field back to the steady state. The influence of the ultrasonic source to electrode separation, temperature of the bulk solution, electrode potential and electrode size on the magnitude of current transients was also studied. All of these parameters affected markedly the magnitude of the current transients recorded at microelectrode in the presence of ultrasound. An alternative approach is presented to characterise fast heterogeneous electron transfer reactions employing ultrasound as a mass transport enhancement tool. Two innovative techniques, sampled-current voltammetry and sampled-mean current voltammetry, were developed during the course of this thesis. The technique of sample-current voltammetry reported values of the standard rate constant of heterogeneous electron transfer of up to 1.2 cm s-1 in the presence of ultrasound. This technique focuses on the electrochemical phenomena under investigation at the point of impact of the ultrasonic event, produced by asymmetric cavitation bubble collapse near the electrode surface. Bubble dynamics were also examined under the experimental conditions employed in the present study. The bubble behaviour was observed from the numerical solution of the RPNNP equation that describes the motion of a gas filled bubble in a homogeneous phase. This equation was solved numerically employing the Fourorder Runge-Kutta method. Finally, a preliminary study of surface process in the presence of ultrasound is presented. Erosion current events were recorded at high time solution. These current events were attributed to the reoxidation of the exposed metal as a result of cavitation events. This study shows that surface erosion can be electrochemically investigated in-situ withing a cavitating media. [Espanol] El efecto del ultrasonido en procesos electroquimicos ha sido investigado empleando un micro-electrodo dentro de un medio cavitante. El transporte de masa transitorio fue realzado fuertemente en la presencia de ultrasonido. Altos indices de la transferencia de masa de hasta 1.5 cm s-1 fueron observados. Estos altos indices de la transferencia de masa fueron atribuidos a dos procesos de la cavitacion. Primero, el colapso de la burbuja en/o cerca de la interfase solido-liquido con la formacion consiguiente de un microjet liquido de alta velocidad dirigido hacia la superficie del electrodo. En segundo lugar, movimiento de la burbuja cerca o dentro de la capa de difusion o del electrodo. Tambien se registraron los simples transitorios de corriente a una alta resolucion de tiempo. Estos transitorios simples de corriente fueron atribuidos a la perturbacion a corto plazo del campo de difusion del micro-electrodo debido a los impactos de cavitacion del colapso de la burbuja seguido por una relajacion de largo tiempo del campo de la difusion de nuevo al estado estable. La influencia de la fuente ultrasonica a la separacion del electrodo, la temperatura total de la solucion, el potencial del electrodo y el tamano del electrodo sobre la magnitud de transitorios de corriente tambien fue estudiada. Todos estos parametros afectaron marcadamente la magnitud de los transitorios de corriente registrados en el micro-electrodo en presencia del ultrasonido. Se presenta una opcion alternativa para caracterizar reacciones heterogeneas rapidas de transferencia del electron que empleando el ultrasonido como herramienta, de realce del transporte de masa. Dos tecnicas innovadoras, la voltametria corriente muestreada y la voltametria corriente-media muestreada, se desarrollaron durante el curso de esta tesis. La tecnica del voltammetria corriente de muestra senalo los valores del regimen estandar constante de la transferencia heterogenea del electron de hasta 1.2 centimetros s-1 en la presencia del ultrasonido. Esta tecnica se centra en los fenomenos electroquimicos bajo investigacion en el punto de impacto del acontecimiento ultrasonico, producido por colapso asimetrico de la burbuja de cavitacion cerca de la superficie del electrodo. Las dinamicas de la burbuja tambien fueron examinadas bajo las condiciones experimentales empleadas en el presente estudio. El comportamiento de la burbuja fue observado desde la solucion numerica de la ecuacion de RPNNP que describe el movimiento de una burbuja llena gas en una fase homogenea. Esta ecuacion fue resuelta numericamente empleando el metodo de cuarto orden de Runge-Kutta. Finalmente se presenta un estudio preliminar del proceso superficial en presencia del ultrasonido. Los eventos de erosion por corriente fueron registrados a una alta resolucion de tiempo. Estos eventos de corriente fueron atribuidos a la re-oxidacion del metal expuesto como resultado de eventos de cavitacion. Este estudio muestra que la erosion superficial puede ser investigada electroquimicamente in situ dentro del medio de cavitacion.

  7. Shock Thermodynamic Applied Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Shock Thermodynamic Applied Research Facility (STAR) facility, within Sandia’s Solid Dynamic Physics Department, is one of a few institutions in the world with...

  8. Shock Thermodynamic Applied Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Shock Thermodynamic Applied Research Facility (STAR) facility, within Sandia’s Solid Dynamic Physics Department, is one of a few institutions in the world with a...

  9. Applied statistical inference with MINITAB

    CERN Document Server

    Lesik, Sally

    2009-01-01

    Through clear, step-by-step mathematical calculations, Applied Statistical Inference with MINITAB enables students to gain a solid understanding of how to apply statistical techniques using a statistical software program. It focuses on the concepts of confidence intervals, hypothesis testing, validating model assumptions, and power analysis.Illustrates the techniques and methods using MINITABAfter introducing some common terminology, the author explains how to create simple graphs using MINITAB and how to calculate descriptive statistics using both traditional hand computations and MINITAB. Sh

  10. Conversation Analysis in Applied Linguistics

    DEFF Research Database (Denmark)

    Kasper, Gabriele; Wagner, Johannes

    2014-01-01

    with understanding fundamental issues of talk in action and of intersubjectivity in human conduct. The field has expanded its scope from the analysis of talk—often phone calls—towards an integration of language with other semiotic resources for embodied action, including space and objects. Much of this expansion has...... been driven by applied work. After laying out CA's standard practices of data treatment and analysis, this article takes up the role of comparison as a fundamental analytical strategy and reviews recent developments into cross-linguistic and cross-cultural directions. The remaining article focuses......For the last decade, conversation analysis (CA) has increasingly contributed to several established fields in applied linguistics. In this article, we will discuss its methodological contributions. The article distinguishes between basic and applied CA. Basic CA is a sociological endeavor concerned...

  11. From art to applied science.

    Science.gov (United States)

    Schatzberg, Eric

    2012-09-01

    Before "applied science" and "technology" became keywords, the concept of art was central to discourse about material culture and its connections to natural knowledge. By the late nineteenth century, a new discourse of applied science had replaced the older discourse of art. This older discourse of art, especially as presented in Enlightenment encyclopedias, addressed the relationship between art and science in depth. But during the nineteenth century the concept of fine art gradually displaced the broader meanings of "art," thus undermining the utility of the term for discourse on the relationship between knowledge and practice. This narrowed meaning of "art" obscured key aspects of the industrial world. In effect, middle-class agents of industrialism, including "men of science," used the rhetoric of "applied science" and, later, "technology" to cement the exclusion of artisanal knowledge from the discourse of industrial modernity.

  12. Applied medical statistics using SAS

    CERN Document Server

    Der, Geoff

    2012-01-01

    ""Each chapter in the book is well laid out, contains examples with SAS code, and ends with a concise summary. The chapters in the book contain the right level of information to use SAS to apply different statistical methods. … a good overview of how to apply in SAS 9.3 the many possible statistical analysis methods.""-Caroline Kennedy, Takeda Development Centre Europe Ltd., Statistical Methods for Medical Research, 2015""… a well-organized and thorough exploration of broad coverage in medical statistics. The book is an excellent reference of statistical methods

  13. Applied analysis and differential equations

    CERN Document Server

    Cârj, Ovidiu

    2007-01-01

    This volume contains refereed research articles written by experts in the field of applied analysis, differential equations and related topics. Well-known leading mathematicians worldwide and prominent young scientists cover a diverse range of topics, including the most exciting recent developments. A broad range of topics of recent interest are treated: existence, uniqueness, viability, asymptotic stability, viscosity solutions, controllability and numerical analysis for ODE, PDE and stochastic equations. The scope of the book is wide, ranging from pure mathematics to various applied fields such as classical mechanics, biomedicine, and population dynamics.

  14. Applying statistics in behavioural research

    NARCIS (Netherlands)

    Ellis, J.L.

    2016-01-01

    Applying Statistics in Behavioural Research is written for undergraduate students in the behavioural sciences, such as Psychology, Pedagogy, Sociology and Ethology. The topics range from basic techniques, like correlation and t-tests, to moderately advanced analyses, like multiple regression and MAN

  15. The Applied Connection for Sociology.

    Science.gov (United States)

    Boros, Alexander

    1984-01-01

    A survey of the 76 graduates of Kent State's applied sociology masters program, designed to prepare students for employment outside academe, found one graduate employed outside her field, four who continued their education and became practicing sociologists, and a majority who used their training as human service practitioners. (MSE)

  16. Applied Linguistics Research on Asianness

    Science.gov (United States)

    Kobayashi, Yoko

    2011-01-01

    As China is increasingly occupying the world's attention, its explosively expanding economical and political clout has also been felt in the applied linguistics domain, with the discussion on China's/Chinese language issues growing by leaps and bounds (e.g. China's English education policies, Chinese language classes in the West). Amid the world's…

  17. Virtual reality applied to teletesting

    NARCIS (Netherlands)

    Berg, T.W. van den; Smeenk, R.J.M.; Mazy, A.; Jacques, P.; Argüello, L.; Mills, S.

    2003-01-01

    The activity "Virtual Reality applied to Teletesting" is related to a wider European Space Agency (ESA) initiative of cost reduction, in particular the reduction of test costs. Reduction of costs of space related projects have to be performed on test centre operating costs and customer company costs

  18. Applying Creativity Research to Cooking

    Science.gov (United States)

    Beghetto, Ronald A.; Kaufman, James C.; Hatcher, Ryan

    2016-01-01

    What, if any, benefit might there be to applying creativity research to cooking? The purpose of this paper was to address this question. Specifically, we draw on concepts and theories from creativity research to help clarify what is meant by creative cooking. This includes exploring creative cooking through the lens of the 4-C and Propulsion…

  19. SEM in applied marketing research

    DEFF Research Database (Denmark)

    Sørensen, Bjarne Taulo; Tudoran, Ana Alina

    In this paper we discuss two SEM approaches: an exploratory structural equation modelling based on a more liberalised and inductive philosophy versus the classical SEM based on the traditional hypothetical-deductive approach. We apply these two modelling techniques to data from a consumer survey ...

  20. Conditional Independence in Applied Probability.

    Science.gov (United States)

    Pfeiffer, Paul E.

    This material assumes the user has the background provided by a good undergraduate course in applied probability. It is felt that introductory courses in calculus, linear algebra, and perhaps some differential equations should provide the requisite experience and proficiency with mathematical concepts, notation, and argument. The document is…

  1. Applying and extending Oracle Spatial

    CERN Document Server

    Simon Gerard Greener, Siva Ravada

    2013-01-01

    This book is an advanced practical guide to applying and extending Oracle Spatial.This book is for existing users of Oracle and Oracle Spatial who have, at a minimum, basic operational experience of using Oracle or an equivalent database. Advanced skills are not required.

  2. Toward an Applied Administrative Science.

    Science.gov (United States)

    Dunbar, Roger L. M.

    1983-01-01

    A study of 65 articles from the 1981 volumes of "Administrative Science Quarterly" and "Harvard Business Review," using smallest space analysis, found that the few studies adopting subjective (instead of objective) approaches to analyzing organizational change were most likely to provide a basis for an applied administrative…

  3. Applied survival analysis using R

    CERN Document Server

    Moore, Dirk F

    2016-01-01

    Applied Survival Analysis Using R covers the main principles of survival analysis, gives examples of how it is applied, and teaches how to put those principles to use to analyze data using R as a vehicle. Survival data, where the primary outcome is time to a specific event, arise in many areas of biomedical research, including clinical trials, epidemiological studies, and studies of animals. Many survival methods are extensions of techniques used in linear regression and categorical data, while other aspects of this field are unique to survival data. This text employs numerous actual examples to illustrate survival curve estimation, comparison of survivals of different groups, proper accounting for censoring and truncation, model variable selection, and residual analysis. Because explaining survival analysis requires more advanced mathematics than many other statistical topics, this book is organized with basic concepts and most frequently used procedures covered in earlier chapters, with more advanced topics...

  4. Modern applied U-statistics

    CERN Document Server

    Kowalski, Jeanne

    2008-01-01

    A timely and applied approach to the newly discovered methods and applications of U-statisticsBuilt on years of collaborative research and academic experience, Modern Applied U-Statistics successfully presents a thorough introduction to the theory of U-statistics using in-depth examples and applications that address contemporary areas of study including biomedical and psychosocial research. Utilizing a "learn by example" approach, this book provides an accessible, yet in-depth, treatment of U-statistics, as well as addresses key concepts in asymptotic theory by integrating translational and cross-disciplinary research.The authors begin with an introduction of the essential and theoretical foundations of U-statistics such as the notion of convergence in probability and distribution, basic convergence results, stochastic Os, inference theory, generalized estimating equations, as well as the definition and asymptotic properties of U-statistics. With an emphasis on nonparametric applications when and where applic...

  5. NIIEFA accelerators for applied purposes

    Science.gov (United States)

    Vorogushin, M. F.; Strokach, A. P.; Filatov, O. G.

    2016-12-01

    Since the foundation of the institute, we have designed and delivered more than three hundred different accelerators to Russia and abroad: cyclotrons, linear accelerators, and neutron generators. The technical characteristics of our equipment makes it competitive on the international market. Here we present the application, main parameters, and status of accelerators manufactured by NIIEFA, as well as prospects for the development of electrophysical systems for applied purposes.

  6. Towards "open applied" Earth sciences

    Science.gov (United States)

    Ziegler, C. R.; Schildhauer, M.

    2014-12-01

    Concepts of open science -- in the context of cyber/digital technology and culture -- could greatly benefit applied and secondary Earth science efforts. However, international organizations (e.g., environmental agencies, conservation groups and sustainable development organizations) that are focused on applied science have been slow to incorporate open practices across the spectrum of scientific activities, from data to decisions. Myriad benefits include transparency, reproducibility, efficiency (timeliness and cost savings), stakeholder engagement, direct linkages between research and environmental outcomes, reduction in bias and corruption, improved simulation of Earth systems and improved availability of science in general. We map out where and how open science can play a role, providing next steps, with specific emphasis on applied science efforts and processes such as environmental assessment, synthesis and systematic reviews, meta-analyses, decision support and emerging cyber technologies. Disclaimer: The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the organizations for which they work and/or represent.

  7. An Applied Physicist Does Econometrics

    Science.gov (United States)

    Taff, L. G.

    2010-02-01

    The biggest problem those attempting to understand econometric data, via modeling, have is that economics has no F = ma. Without a theoretical underpinning, econometricians have no way to build a good model to fit observations to. Physicists do, and when F = ma failed, we knew it. Still desiring to comprehend econometric data, applied economists turn to mis-applying probability theory---especially with regard to the assumptions concerning random errors---and choosing extremely simplistic analytical formulations of inter-relationships. This introduces model bias to an unknown degree. An applied physicist, used to having to match observations to a numerical or analytical model with a firm theoretical basis, modify the model, re-perform the analysis, and then know why, and when, to delete ``outliers'', is at a considerable advantage when quantitatively analyzing econometric data. I treat two cases. One is to determine the household density distribution of total assets, annual income, age, level of education, race, and marital status. Each of these ``independent'' variables is highly correlated with every other but only current annual income and level of education follow a linear relationship. The other is to discover the functional dependence of total assets on the distribution of assets: total assets has an amazingly tight power law dependence on a quadratic function of portfolio composition. Who knew? )

  8. The effect of oxygen vacancies on the structure and electrochemistry of LiTi{sub 2}(PO{sub 4}){sub 3} for lithium-ion batteries: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Jia-Yan; He, Ping; Xia, Yong-Yao [Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, Handan Road 220, Shanghai 200433 (China); Chen, Li-Juan; Zhao, Yu-Jun [Department of Physics, South China University of Technology, Guangzhou 510640 (China)

    2009-12-01

    We report that a partially oxygen deficient LiTi{sub 2}(PO{sub 4}){sub 3} shows a much better rate capability as a cathode material for lithium-ion batteries compared to stoichiometric LiTi{sub 2}(PO{sub 4}){sub 3}. A combination of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemistry, and first-principles calculations was used to determine and rationalize the structural and electrical changes that occur with different heat treatment atmospheres. XRD and XPS experiments confirmed that some Ti{sup 4+} transformed to Ti{sup 3+} in oxygen deficient LiTi{sub 2}(PO{sub 4}){sub 3} heat treated under N{sub 2}; Ti{sup 3+} was detected and the lattice parameter increased compared to that of LiTi{sub 2}(PO{sub 4}){sub 3}. Electrical conductivity measurements indicated an increase in the electronic conductivity of nearly two orders of magnitude for the oxygen deficient LiTi{sub 2}(PO{sub 4}){sub 3} sample compared to LiTi{sub 2}(PO{sub 4}){sub 3}. First-principles calculations suggest that the oxygen vacancies could be formed in LiTi{sub 2}(PO{sub 4}){sub 3} under oxygen-poor conditions, and this may significantly decrease the donor levels of other possible donor defects and thus improve the electronic mobility. (author)

  9. Structural, magnetic and optical properties of an Fe(III) dimer bridged by the meridional planar divergent N,N'-bis(salicyl)hydrazide and its photo- and electro-chemistry in solution.

    Science.gov (United States)

    Cheaib, Khaled; Martel, David; Clément, Nicolas; Eckes, Fabrice; Kouaho, Stéphanie; Rogez, Guillaume; Dagorne, Samuel; Kurmoo, Mohamedally; Choua, Sylvie; Welter, Richard

    2013-02-07

    {Fe(III)Cl(DMF)(2)}(2)(L) where L is N,N'-bis(salicyl)hydrazide has been synthesized as red crystals and characterized using single-crystal diffraction, infrared and UV-vis spectroscopies, and its magnetic properties studied. The dimeric unit in the structure is formed through the two meridional sets of divergent O, N, O coordinating atoms of the hexacoordinated and quadruply charged ligand. With the presence of the inversion symmetry the Fe atoms are strictly planar with the ligand. The magnetic exchange interaction is found to be antiferromagnetic with a J = -5.98(3) cm(-1) through the rare Fe-N-N-Fe pathway. Irradiation of the FeCl(3)/H(4)L red DMF solution in the visible region of the spectrum resulted in its complete discoloration and from which the unknown colorless salt [Fe(II)(DMF)(6)][Fe(II)Cl(4)] and the neutral ligand have been identified by single crystal diffraction. The UV-visible spectra of FeCl(3), H(4)L and their mixture in DMF solution indicate that the iron complex is the absorbing species and the presence of the free ligand in the irradiated solution suggests that the ligand is potentially acting as a catalyst to the photoreduction of Fe(III) to Fe(II), while electrochemistry points to a mixed-valent (Fe(II)-Fe(III)) intermediate in the process.

  10. Applied gamma-ray spectrometry

    CERN Document Server

    Dams, R; Crouthamel, Carl E

    1970-01-01

    Applied Gamma-Ray Spectrometry covers real life application of the gamma-ray and the devices used in their experimental studies. This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the observed gamma-ray and X-ray spectra. The subsequent chapters deal with the properties and fabrication of scintillation detectors, semiconductor detectors, and proportional gas counters. These chapters present some of the most widely utilized

  11. Applied Mathematical Problems in Engineering

    Directory of Open Access Journals (Sweden)

    Carlos Llopis-Albert

    2016-10-01

    Full Text Available There is a close relationship between engineering and mathematics, which has led to the development of new techniques in recent years. Likewise the developments in technology and computers have led to new ways of teaching mathematics for engineering students and the use of modern techniques and methods.  This research aims to provide insight on how to deal with mathematical problems for engineering students. This is performed by means of a fuzzy set/Qualitative Comparative Analysis applied to conflict resolution of Public Participation Projects in support to the EU Water Framework Directive.

  12. Comprehensive Environmental Assessment Applied to ...

    Science.gov (United States)

    In September 2013, EPA announced the availability of the final report, Comprehensive Environmental Assessment Applied to Multiwalled Carbon Nanotube Flame-Retardant Coatings in Upholstery Textiles: A Case Study Presenting Priority Research Gaps for Future Risk Assessments. This final report presents a case study of multiwalled carbon nanotubes (MWCNTs); it focuses on the specific example of MWCNTs as used in flame-retardant coatings applied to upholstery textiles. This case study is organized around the comprehensive environmental assessment (CEA) framework, which structures available information pertaining to the product life cycle, environmental transport and fate, exposure-dose in receptors (i.e., humans, ecological populations, and the environment), and potential impacts in these receptors. A group of experts representing multiple disciplines and multiple sector perspectives used an earlier draft of the case study in conjunction with a structured workshop process to identify and prioritize research gaps that, if pursued, could inform future MWCNT assessment efforts. The final report is not a health, risk, or exposure assessment and as such does not draw conclusions about potential risks, or present an exhaustive review of the literature. Rather, it presents the MWCNT research priorities that experts identified in this application of CEA in order to aid research planning throughout the scientific community. The outcomes of these research efforts may subsequ

  13. Workshop applied antineutrino physics 2007

    Energy Technology Data Exchange (ETDEWEB)

    Akiri, T.; Andrieu, B.; Anjos, J.; Argyriades, J.; Barouch, G.; Bernstein, A.; Bersillon, O.; Besida, O.; Bowden, N.; Cabrera, A.; Calmet, D.; Collar, J.; Cribier, M.; Kerret, H. de; Meijer, R. de; Dudziak, F.; Enomoto, S.; Fallot, M.; Fioni, G.; Fiorentini, G.; Gale, Ph.; Georgadze, A.; Giot, L.; Gonin, M.; Guillon, B.; Henson, C.; Jonkmans, G.; Kanamaru, S.; Kawasaki, T.; Kornoukhov, V.; Lasserre, Th.; Learned, J.G.; Lefebvre, J.; Letourneau, A.; Lhillier, D.; Lindner, M.; Lund, J.; Mantovani, F.; Mcdonough, B.; Mention, G.; Monteith, A.; Motta, D.; Mueller, Th.; Oberauer, L.; Obolensky, M.; Odrzywolek, A.; Petcov, S.; Porta, A.; Queval, R.; Reinhold, B.; Reyna, D.; Ridikas, D.; Sadler, L.; Schoenert, St.; Sida, J.L.; Sinev, V.; Suekane, F.; Suvorov, Y.; Svoboda, R.; Tang, A.; Tolich, N.; Tolich, K.; Vanka, S.; Vignaud, D.; Volpe, Ch.; Wong, H

    2007-07-01

    The 'Applied Antineutrino Physics 2007' workshop is the fourth international meeting devoted to the opening of the neutrino physics to more applied fields, such as geophysics and geochemistry, nuclear industry, as well as the nonproliferation. This meeting highlights the world efforts already engaged to exploit the single characteristics of the neutrinos for the control of the production of plutonium in the civil nuclear power reactor. The potential industrial application of the measurement of the thermal power of the nuclear plants by the neutrinos is also approached. earth neutrinos were for the first time highlighted in 2002 by the KamLAND experiment. Several international efforts are currently underway to use earth neutrinos to reveal the interior of the Earth. This meeting is an opportunity to adapt the efforts of detection to the real needs of geophysicists and geochemists (sources of radiogenic heat, potassium in the court, feathers.) Finally more futuristic topics such as the detection of nuclear explosions, of low powers, are also discussed. This document gathers only the slides of the presentations.

  14. Numerical simulation in applied geophysics

    CERN Document Server

    Santos, Juan Enrique

    2016-01-01

    This book presents the theory of waves propagation in a fluid-saturated porous medium (a Biot medium) and its application in Applied Geophysics. In particular, a derivation of absorbing boundary conditions in viscoelastic and poroelastic media is presented, which later is employed in the applications. The partial differential equations describing the propagation of waves in Biot media are solved using the Finite Element Method (FEM). Waves propagating in a Biot medium suffer attenuation and dispersion effects. In particular the fast compressional and shear waves are converted to slow diffusion-type waves at mesoscopic-scale heterogeneities (on the order of centimeters), effect usually occurring in the seismic range of frequencies. In some cases, a Biot medium presents a dense set of fractures oriented in preference directions. When the average distance between fractures is much smaller than the wavelengths of the travelling fast compressional and shear waves, the medium behaves as an effective viscoelastic an...

  15. Applied public-key steganography

    Science.gov (United States)

    Guillon, Pierre; Furon, Teddy; Duhamel, Pierre

    2002-04-01

    We consider the problem of hiding information in a steganographic framework, i.e. embedding a binary message within an apparently innocuous content, in order to establish a suspicion-free digital communication channel. The adversary is passive as no intentional attack is foreseen. The only threat is that she discovers the presence of a hidden communication. The main goal of this article is to find if the Scalar Costa Scheme, a recently published embedding method exploiting side information at the encoder, is suitable for that framework. We justify its use assessing its security level with respect to the Cachin's criterion. We derive a public-key stego-system following the ideas of R. Anderson and P. Petitcolas. This technique is eventually applied to PCM audio contents. Experimental performances are detailed in terms of bit-rate and Kullback-Leibler distance.

  16. Emotional Value of Applied Textiles

    DEFF Research Database (Denmark)

    Bang, Anne Louise

    2011-01-01

    The present PhD thesis is conducted as an Industrial PhD project in collaboration with the Danish company Gabriel A/S (Gabriel), which designs and produces furniture textiles and ‘related products’ for manufacturers of furniture. A ‘related textile product’ is e.g. processing of piece goods...... at Gabriel face while trying to implement an innovative and process-oriented business strategy. The focal point has been the section of the strategy which aims at developing Blue Ocean products, which have a functional and an emotional value for the user. The thesis examines and explores emotional value...... (procedures of user and stakeholder involvement). In the course of the thesis I explain and elaborate on four themes each of which contributes to the outcome of the project. 1) Creating a frame of reference for the textile design process and a systematic approach to applied textiles. In chapter three I...

  17. Special Functions for Applied Scientists

    CERN Document Server

    Mathai, A M

    2008-01-01

    Special Functions for Applied Scientists provides the required mathematical tools for researchers active in the physical sciences. The book presents a full suit of elementary functions for scholars at the PhD level and covers a wide-array of topics and begins by introducing elementary classical special functions. From there, differential equations and some applications into statistical distribution theory are examined. The fractional calculus chapter covers fractional integrals and fractional derivatives as well as their applications to reaction-diffusion problems in physics, input-output analysis, Mittag-Leffler stochastic processes and related topics. The authors then cover q-hypergeometric functions, Ramanujan's work and Lie groups. The latter half of this volume presents applications into stochastic processes, random variables, Mittag-Leffler processes, density estimation, order statistics, and problems in astrophysics. Professor Dr. A.M. Mathai is Emeritus Professor of Mathematics and Statistics, McGill ...

  18. [Basic science and applied science].

    Science.gov (United States)

    Pérez-Tamayo, R

    2001-01-01

    A lecture was presented by the author at the Democratic Opinion Forum on Health Teaching and Research, organized by Mexico's National Health Institutes Coordinating Office, at National Cardiology Institute "Ignacio Chavez", where he presented a critical review of the conventional classification of basic and applied science, as well as his personal view on health science teaching and research. According to the author, "well-conducted science" is that "generating reality-checked knowledge" and "mis-conducted science" is that "unproductive or producing 'just lies' and 'non-fundable'. To support his views, the author reviews utilitarian and pejorative definitions of science, as well as those of committed and pure science, useful and useless science, and practical and esoterical science, as synonyms of applied and basic science. He also asserts that, in Mexico, "this classification has been used in the past to justify federal funding cutbacks to basic science, allegedly because it is not targeted at solving 'national problems' or because it was not relevant to priorities set in a given six-year political administration period". Regarding health education and research, the author asserts that the current academic programs are inefficient and ineffective; his proposal to tackle these problems is to carry out a solid scientific study, conducted by a multidisciplinary team of experts, "to design the scientific researcher curricula from recruitment of intelligent young people to retirement or death". Performance assessment of researchers would not be restricted to publication of papers, since "the quality of scientific work and contribution to the development of science is not reflected by the number of published papers". The English version of this paper is available at: http://www.insp.mx/salud/index.html

  19. Applied extreme-value statistics

    Energy Technology Data Exchange (ETDEWEB)

    Kinnison, R.R.

    1983-05-01

    The statistical theory of extreme values is a well established part of theoretical statistics. Unfortunately, it is seldom part of applied statistics and is infrequently a part of statistical curricula except in advanced studies programs. This has resulted in the impression that it is difficult to understand and not of practical value. In recent environmental and pollution literature, several short articles have appeared with the purpose of documenting all that is necessary for the practical application of extreme value theory to field problems (for example, Roberts, 1979). These articles are so concise that only a statistician can recognise all the subtleties and assumptions necessary for the correct use of the material presented. The intent of this text is to expand upon several recent articles, and to provide the necessary statistical background so that the non-statistician scientist can recognize and extreme value problem when it occurs in his work, be confident in handling simple extreme value problems himself, and know when the problem is statistically beyond his capabilities and requires consultation.

  20. Computer simulations applied in materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    This workshop takes stock of the simulation methods applied to nuclear materials and discusses the conditions in which these methods can predict physical results when no experimental data are available. The main topic concerns the radiation effects in oxides and includes also the behaviour of fission products in ceramics, the diffusion and segregation phenomena and the thermodynamical properties under irradiation. This document brings together a report of the previous 2002 workshop and the transparencies of 12 presentations among the 15 given at the workshop: accommodation of uranium and plutonium in pyrochlores; radiation effects in La{sub 2}Zr{sub 2}O{sub 7} pyrochlores; first principle calculations of defects formation energies in the Y{sub 2}(Ti,Sn,Zr){sub 2}O{sub 7} pyrochlore system; an approximate approach to predicting radiation tolerant materials; molecular dynamics study of the structural effects of displacement cascades in UO{sub 2}; composition defect maps for A{sup 3+}B{sup 3+}O{sub 3} perovskites; NMR characterization of radiation damaged materials: using simulation to interpret the data; local structure in damaged zircon: a first principle study; simulation studies on SiC; insertion and diffusion of He in 3C-SiC; a review of helium in silica; self-trapped holes in amorphous silicon dioxide: their short-range structure revealed from electron spin resonance and optical measurements and opportunities for inferring intermediate range structure by theoretical modelling. (J.S.)

  1. Applied discrete-time queues

    CERN Document Server

    Alfa, Attahiru S

    2016-01-01

    This book introduces the theoretical fundamentals for modeling queues in discrete-time, and the basic procedures for developing queuing models in discrete-time. There is a focus on applications in modern telecommunication systems. It presents how most queueing models in discrete-time can be set up as discrete-time Markov chains. Techniques such as matrix-analytic methods (MAM) that can used to analyze the resulting Markov chains are included. This book covers single node systems, tandem system and queueing networks. It shows how queues with time-varying parameters can be analyzed, and illustrates numerical issues associated with computations for the discrete-time queueing systems. Optimal control of queues is also covered. Applied Discrete-Time Queues targets researchers, advanced-level students and analysts in the field of telecommunication networks. It is suitable as a reference book and can also be used as a secondary text book in computer engineering and computer science. Examples and exercises are includ...

  2. Applied computation and security systems

    CERN Document Server

    Saeed, Khalid; Choudhury, Sankhayan; Chaki, Nabendu

    2015-01-01

    This book contains the extended version of the works that have been presented and discussed in the First International Doctoral Symposium on Applied Computation and Security Systems (ACSS 2014) held during April 18-20, 2014 in Kolkata, India. The symposium has been jointly organized by the AGH University of Science & Technology, Cracow, Poland and University of Calcutta, India. The Volume I of this double-volume book contains fourteen high quality book chapters in three different parts. Part 1 is on Pattern Recognition and it presents four chapters. Part 2 is on Imaging and Healthcare Applications contains four more book chapters. The Part 3 of this volume is on Wireless Sensor Networking and it includes as many as six chapters. Volume II of the book has three Parts presenting a total of eleven chapters in it. Part 4 consists of five excellent chapters on Software Engineering ranging from cloud service design to transactional memory. Part 5 in Volume II is on Cryptography with two book...

  3. CHINESE JOURNAL OF APPLIED MECHANICS

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Analytical analysis of supporting circular tunnel construction in viscoelastic rock mass Wang Huaning Zhong Zheng (School of Aerospace Engineering and Applied Mechanics, Tongji University, 200092, Shanghai, China) Abstract: Tunnel excavation and supporting are continuous processes. The time related deformation is due to rheologie behavior of rock mass and construction process. Time-varying function of radius is established to simulate the circular tunnel excavation process. The stresses and displacement general solutions of viscoelastic rock mass with elastic support during construction are derived by Laplace transformation method, which contains the undetermined supporting force. Volterra integral equation of supporting force is established by substituting different radius excavation function and surface force of excavation and supporting stage into the contact conditions. For Boltzmann viscoelastic model, supporting force can be calculated exactly. The expression and example show that radial displacement after supporting is increased with exponential form and stabilized to one value. If final tunnel is the same size and supported immediately in the finish time but excavated with different velocity, the displacement of cases with high velocity is larger in the beginning and smaller after some time. The final steady displacement is also smaller when excavated faster, but the displacement occurred after supporting is larger. The solutions can be calculated for cases with arbitrary time-varying radius and the method is applicable for the analysis of other viscoelastic models. Keywords: viscoelasticity, construction process, support, analytical analysis

  4. Applying lean thinking in construction

    Directory of Open Access Journals (Sweden)

    Remon Fayek Aziz

    2013-12-01

    Full Text Available The productivity of the construction industry worldwide has been declining over the past 40 years. One approach for improving the situation is using lean construction. Lean construction results from the application of a new form of production management to construction. Essential features of lean construction include a clear set of objectives for the delivery process, aimed at maximizing performance for the customer at the project level, concurrent design, construction, and the application of project control throughout the life cycle of the project from design to delivery. An increasing number of construction academics and professionals have been storming the ramparts of conventional construction management in an effort to deliver better value to owners while making real profits. As a result, lean-based tools have emerged and have been successfully applied to simple and complex construction projects. In general, lean construction projects are easier to manage, safer, completed sooner, and cost less and are of better quality. Significant research remains to complete the translation to construction of lean thinking in Egypt. This research will discuss principles, methods, and implementation phases of lean construction showing the waste in construction and how it could be minimized. The Last Planner System technique, which is an important application of the lean construction concepts and methodologies and is more prevalent, proved that it could enhance the construction management practices in various aspects. Also, it is intended to develop methodology for process evaluation and define areas for improvement based on lean approach principles.

  5. Electrochemistry and Spectroelectrochemistry of 1,8-Naphthalene and 1,8- Anthracene-Linked Cofacial Binuclear Metallophthalocynanines. New Mixed Valence Metallopthalocyanines

    Science.gov (United States)

    1990-05-10

    cyclic voltametry at 200, 100, 50 and 20 mV/s, Average data being E : (Eps + Epc)/2 are reported. Data in parenthesis are estimated from overlapping...Perkin-Elmer Hitachi Model 340 microprocessor spectrometer. Cyclic and differential pulse voltammetry were performed with a Princeton Applied Research...and dried under reduced pressure. Judging from the cyclic voltammetric curve under argon at the prepared electrode, the surface concentration of the

  6. The System Combined Electrochemistry and Electron Spectroscopy and the Investigation of Surface Chemical States of Pt/Sb and Pt/Bi Electrode%固/液界面电化学体系与XPS联用系统对Pt/Sb和Pt/Bi电极表面化学状态的比较研究

    Institute of Scientific and Technical Information of China (English)

    薛国庆; 陈声培; 孙世刚

    2002-01-01

    利用已建立的固/液界面电化学体系Electrochemistry(EC)与超高真空电子能谱Ultra-High Vacaum X-ray Photoelectron Spectroscopy(UHV-XPS)联用系统详细研究了Pt电极表面欠电位沉积Underpotential deposition(UPD)Sb、Bi的表面化学状态特征,结果表明Sb、Bi虽同为VA族元素,但二者在Pt电极表面的UPD特征却有很大差异.

  7. Gaitography applied to prosthetic walking.

    Science.gov (United States)

    Roerdink, Melvyn; Cutti, Andrea G; Summa, Aurora; Monari, Davide; Veronesi, Davide; van Ooijen, Mariëlle W; Beek, Peter J

    2014-11-01

    During walking on an instrumented treadmill with an embedded force platform or grid of pressure sensors, center-of-pressure (COP) trajectories exhibit a characteristic butterfly-like shape, reflecting the medio-lateral and anterior-posterior weight shifts associated with alternating steps. We define "gaitography" as the analysis of such COP trajectories during walking (the "gaitograms"). It is currently unknown, however, if gaitography can be employed to characterize pathological gait, such as lateralized gait impairments. We therefore registered gaitograms for a heterogeneous sample of persons with a trans-femoral and trans-tibial amputation during treadmill walking at a self-selected comfortable speed. We found that gaitograms directly visualize between-person differences in prosthetic gait in terms of step width and the relative duration of prosthetic and non-prosthetic single-support stance phases. We further demonstrated that one should not only focus on the gaitogram's shape but also on the time evolution along that shape, given that the COP evolves much slower in the single-support phase than in the double-support phase. Finally, commonly used temporal and spatial prosthetic gait characteristics were derived, revealing both individual and systematic differences in prosthetic and non-prosthetic step lengths, step times, swing times, and double-support durations. Because gaitograms can be rapidly collected in an unobtrusive and markerless manner over multiple gait cycles without constraining foot placement, clinical application of gaitography seems both expedient and appealing. Studies examining the repeatability of gaitograms and evaluating gaitography-based gait characteristics against a gold standard with known validity and reliability are required before gaitography can be clinically applied.

  8. Counterforce applied to prevent spalling

    Energy Technology Data Exchange (ETDEWEB)

    Glamheden, Rune; Bergkvist, Lars (Golder Associates AB (Sweden)); Faelth, Billy (Clay Technology AB, Lund (Sweden)); Jacobsson, Lars (SP Technical Research Institute of Sweden, Boraas (Sweden)); Harrstroem, Johan (Geosigma AB, Uppsala (Sweden)); Berglund, Johan (Vattenfall Power Consultant AB, Stockholm (Sweden))

    2010-04-15

    The field experiment within CAPS (Counterforce Applied to Prevent Spalling) was initiated to determine if the application of dry bentonite pellets is sufficient to suppress thermally-induced spalling in KBS-3 deposition holes. The experience gained from Aespoe Pillar Stability Experiment, conducted between 2002 and 2006, indicated that spalling could be controlled by the application of a small confining pressure in the deposition holes. The CAPS field experiment that included four pairs of boreholes with a diameter of approximately 0.5 m, was carried out as a series of demonstration experiments in the TASQ-tunnel. The first and second heating tests were performed in open holes, without any confining pressure on the borehole wall and the third and fourth heating tests with a confining pressure created by expanded clay pellets (LECA). The first heating test was initiated at the end of August 2008 and the final test was finished at the end of May 2009. The trials suggest that the small confining pressure offered by the LECA pellets was adequate to control spalling and prevent the formation of a highly conductive zone of fractured rock in the 500-mm-diameter holes. It is recommended that a full-scale test be carried out to assess if the findings are applicable to 1,750-mm-diameter deposition holes. Should the full scale tests support the findings from these initial trials, filling the gap between the bentonite blocks and rock wall with dry bentonite pellets will provide a viable engineered solution for controlling the effects of thermally induced spalling in the KBS-3 deposition holes

  9. Research on the treatment of fracturing flow-back fluid by coagulation-magnet separation-electrochemistry combined technology%混凝-磁分离-电化学技术处理压裂返排液研究

    Institute of Scientific and Technical Information of China (English)

    张太亮; 欧阳铖; 郭威; 张芳捷; 范开鑫

    2016-01-01

    The components,characteristics and treatment actuality of fracturing flow-back fluid from shale gas explo-ration are analyzed. It is put forward that the gel-breaking coagulation-magnetic separation-electrochemistry catalysis oxidation technology is used for treating fracturing flow-back fluid. The optimized technology of every treatment unit is obtained through researches,among which gel-breaker K2FeO4 is used in the gel-breaking coagulation process. The conditions needed are as follows:the dosage of K2FeO4 is 2 500 mg/L,PAFC dosage 2 000 mg/L, reacting pH 11.0 and reaction time 40 min. Nano-magnet powder 4 000 mg/L and polymer flocculant HPAM 20 mg/L are needed for the magnetic separation process. Ti/TiO2 plate is used as anode,while stainless steel plate as cathode, oxidation voltage 10.0 V,current density1.6×10-2 A/cm2,reaction pH of the system 11.0 and reaction time 30 min are needed for the electrochemistry catalysis oxidation process. The research results show that after the above technology and optimized processes have been used for the treatment of fracturing flow-back fluid,all of the main factors,such as COD,SS,oil content,chroma,pH,etc. meet the requirements specified in the first class of the Integrated Wastewater Discharge Standard(GB 8978—2002).%对页岩气开采中压裂返排液的组成、特性及处理现状进行分析,提出采用破胶混凝—磁分离—电化学催化氧化技术处理压裂返排液。研究得到各处理单元优化工艺,其中破胶混凝工艺采用高铁酸钾破胶剂、投加量2500 mg/L,混凝剂聚合氯化铝铁投加量为2000 mg/L,反应pH为11.0,反应时间40 min;磁分离工艺采用纳米磁铁粉,投加量4000 mg/L,高分子絮凝剂阴离子聚丙烯酰胺投加量为20 mg/L;电化学催化氧化工艺采用Ti/TiO2作阳极,不锈钢作阴极,氧化电压10.0 V,电流密度1.6×10-2 A/cm2,体系pH为11.0,反应时间30 min。研究结果表明,采用上述技术及优

  10. Morphometrics applied to medical entomology.

    Science.gov (United States)

    Dujardin, Jean-Pierre

    2008-12-01

    Morphometrics underwent a revolution more than one decade ago. In the modern morphometrics, the estimate of size is now contained in a single variable reflecting variation in many directions, as many as there are landmarks under study, and shape is defined as their relative positions after correcting for size, position and orientation. With these informative data, and the corresponding software freely available to conduct complex analyses, significant biological and epidemiological features can be quantified more accurately. We discuss the evolutionary significance of the environmental impact on metric variability, mentioning the importance of concepts like genetic assimilation, genetic accommodation, and epigenetics. We provide examples of measuring the effect of selection on metric variation by comparing (unpublished) Qst values with corresponding (published) Fst. The primary needs of medical entomologists are to distinguish species, especially cryptic species, and to detect them where they are not expected. We explain how geometric morphometrics could apply to these questions, and where there are deficiencies preventing the approach from being utilized at its maximum potential. Medical entomologists in connection with control programs aim to identify isolated populations where the risk of reinfestation after treatment would be low ("biogeographical islands"). Identifying them can be obtained from estimating the number of migrants per generation. Direct assessment of movement remains the most valid approach, but it scores active movement only. Genetic methods estimating gene flow levels among interbreeding populations are commonly used, but gene flow does not necessarily mean the current flow of migrants. Methods using the morphometric variation are neither suited to evaluate gene flow, nor are they adapted to estimate the flow of migrants. They may provide, however, the information needed to create a preliminary map pointing to relevant areas where one could

  11. Applied Materials taas investorite huviorbiidis / Erlend Zirk

    Index Scriptorium Estoniae

    Zirk, Erlend

    2006-01-01

    Ilmunud ka: Delovõje Vedomosti 29. nov. lk. 33. Protsessorite tootmisseadmete tootja Applied Materials on pärast 2000. aasta börsikrahhi taas investorite huviorbiiti jõudmas. Diagramm: Applied Materialsi aktsia

  12. Applied Psycholinguistics--Amphibian or Phantom?

    Science.gov (United States)

    Titone, Renzo

    1975-01-01

    A tentative classification of internal departments of psycholinguistics is suggested and a list of applied fields is presented. Applied psycholinguistics is not seen here to have a right to scientific independence. (SCC)

  13. Applied technology section. Monthly report, December 1993

    Energy Technology Data Exchange (ETDEWEB)

    Buckner, M.R.

    1994-01-28

    This monthly report contains abstracts of the progress made in various projects from the applied technology section at the Savannah River Plant. Research areas include engineering modeling and simulation, applied physics, experimental thermal hydraulics, and packaging and transportation.

  14. Applied Parallel Computing Industrial Computation and Optimization

    DEFF Research Database (Denmark)

    Madsen, Kaj; NA NA NA Olesen, Dorte

    Proceedings and the Third International Workshop on Applied Parallel Computing in Industrial Problems and Optimization (PARA96)......Proceedings and the Third International Workshop on Applied Parallel Computing in Industrial Problems and Optimization (PARA96)...

  15. Western Perspectives in Applied Linguistics in Africa

    Science.gov (United States)

    Makoni, Sinfree; Meinhof, Ulrike H.

    2004-01-01

    The aim of this article is to analyze the nature of the historical and contemporary social contexts within which applied linguistics in Africa emerged, and is currently practiced. The article examines the challenges "local" applied Linguistics in Africa is confronted with as it tries to amplify applied linguistic programs emanating from…

  16. Critical and Alternative Directions in Applied Linguistics

    Science.gov (United States)

    Pennycook, Alastair

    2010-01-01

    Critical directions in applied linguistics can be understood in various ways. The term "critical" as it has been used in "critical applied linguistics," "critical discourse analysis," "critical literacy" and so forth, is now embedded as part of applied linguistic work, adding an overt focus on questions of power and inequality to discourse…

  17. An Efficient CuxO Photocathode for Hydrogen Production at Neutral pH: New Insights from Combined Spectroscopy and Electrochemistry.

    Science.gov (United States)

    Baran, Tomasz; Wojtyła, Szymon; Lenardi, Cristina; Vertova, Alberto; Ghigna, Paolo; Achilli, Elisabetta; Fracchia, Martina; Rondinini, Sandra; Minguzzi, Alessandro

    2016-08-24

    Light-driven water splitting is one of the most promising approaches for using solar energy in light of more sustainable development. In this paper, a highly efficient p-type copper(II) oxide photocathode is studied. The material, prepared by thermal treatment of CuI nanoparticles, is initially partially reduced upon working conditions and soon reaches a stable form. Upon visible-light illumination, the material yields a photocurrent of 1.3 mA cm(-2) at a potential of 0.2 V vs a reversible hydrogen electrode at mild pH under illumination by AM 1.5 G and retains 30% of its photoactivity after 6 h. This represents an unprecedented result for a nonprotected Cu oxide photocathode at neutral pH. The photocurrent efficiency as a function of the applied potential was determined using scanning electrochemical microscopy. The material was characterized in terms of photoelectrochemical features; X-ray photoelectron spectroscopy, X-ray absorption near-edge structure, fixed-energy X-ray absorption voltammetry, and extended X-ray absorption fine structure analyses were carried out on pristine and used samples, which were used to explain the photoelectrochemical behavior. The optical features of the oxide are evidenced by direct reflectance spectroscopy and fluorescence spectroscopy, and Mott-Schottky analysis at different pH values explains the exceptional activity at neutral pH.

  18. Fast and simultaneous detection of heavy metals using a simple and reliable microchip-electrochemistry route: An alternative approach to food analysis.

    Science.gov (United States)

    Chailapakul, Orawon; Korsrisakul, Sarawadee; Siangproh, Weena; Grudpan, Kate

    2008-01-15

    This paper reports, for the first, the fast and simultaneous detection of prominent heavy metals, including: lead, cadmium and copper using microchip CE with electrochemical detection. The direct amperometric detection mode for microchip CE was successfully applied to these heavy metal ions. The influences of separation voltage, detection potential, as well as the concentration and pH value of the running buffer on the response of the detector were carefully assayed and optimized. The results clearly show that reliable analysis for lead, cadmium, and copper by the degree of electrophoretic separation occurs in less than 3min using a MES buffer (pH 7.0, 25mM) and l-histidine, with 1.2kV separation voltage and -0.8V detection potential. The detection limits for Pb(2+), Cd(2+), and Cu(2+) were 1.74, 0.73 and 0.13microM (S/N=3). The %R.S.D. of each peak current was foods.

  19. Towards quantitative measures in applied ontology

    CERN Document Server

    Hoehndorf, Robert; Gkoutos, Georgios V

    2012-01-01

    Applied ontology is a relatively new field which aims to apply theories and methods from diverse disciplines such as philosophy, cognitive science, linguistics and formal logics to perform or improve domain-specific tasks. To support the development of effective research methodologies for applied ontology, we critically discuss the question how its research results should be evaluated. We propose that results in applied ontology must be evaluated within their domain of application, based on some ontology-based task within the domain, and discuss quantitative measures which would facilitate the objective evaluation and comparison of research results in applied ontology.

  20. Combination of electrochemistry with chemometrics to introduce an efficient analytical method for simultaneous quantification of five opium alkaloids in complex matrices.

    Science.gov (United States)

    Gholivand, Mohammad-Bagher; Jalalvand, Ali R; Goicoechea, Hector C; Gargallo, Raimundo; Skov, Thomas; Paimard, Giti

    2015-01-01

    For the first time, an analytical methodology based on differential pulse voltammetry (DPV) at a glassy carbon electrode (GCE) and integration of three efficient strategies including variable selection based on ant colony optimization (ACO), mathematical pre-processing selection by genetic algorithm (GA), and sample selection (SS) through a distance-based procedure to improve partial least squares-1 (PLS-1, ACO-GA-SS-PLS-1) multivariate calibration (MVC) for the simultaneous determination of five opium alkaloids including morphine (MOP), noscapine (NOP), thebaine (TEB), codeine (COD), and papaverine (PAP) was used and validated. The baselines of the DPV signals were modeled as a smooth curve, using P-splines, a combination of B-splines and a discrete roughness penalty. After subtraction of the baseline we got a signal with a two-component probability density. One component was for the peaks and it was approximated by a uniform distribution on the potential axis. The other component was for the observed noise around the baseline. Some sources of bi-linearity deviation for electrochemical data were discussed and analyzed. The lack of bi-linearity was tackled by potential shift correction using correlation optimized warping (COW) algorithm. The MVC model was developed as a quinternary calibration model in a blank human serum sample (drug-free) provided by a healthy volunteer to regard the presence of a strong matrix effect which may be caused by the possible interferents present in the serum, and it was validated and tested with two independent sets of analytes mixtures in the blank and actual human serum samples, respectively. Fortunately, the proposed methodology was successful in simultaneous determination of MOP, NOP, TEB, COD, and PAP in both blank and actual human serum samples and its results were satisfactory comparable to those obtained by applying the reference method based on high performance liquid chromatography-ultraviolet detection (HPLC-UV).

  1. Direct Electrochemistry of Hemoglobin Immobilized on a Functionalized Multi-Walled Carbon Nanotubes and Gold Nanoparticles Nanocomplex-Modified Glassy Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Nader Sheibani

    2013-07-01

    Full Text Available Direct electron transfer of hemoglobin (Hb was realized by immobilizing Hb on a carboxyl functionalized multi-walled carbon nanotubes (FMWCNTs and gold nanoparticles (AuNPs nanocomplex-modified glassy carbon electrode. The ultraviolet-visible absorption spectrometry (UV-Vis, transmission electron microscopy (TEM and Fourier transform infrared (FTIR methods were utilized for additional characterization of the AuNPs and FMWCNTs. The cyclic voltammogram of the modified electrode has a pair of well-defined quasi-reversible redox peaks with a formal potential of −0.270 ± 0.002 V (vs. Ag/AgCl at a scan rate of 0.05 V/s. The heterogeneous electron transfer constant (ks was evaluated to be 4.0 ± 0.2 s−1. The average surface concentration of electro-active Hb on the surface of the modified glassy carbon electrode was calculated to be 6.8 ± 0.3 × 10−10 mol cm−2. The cathodic peak current of the modified electrode increased linearly with increasing concentration of hydrogen peroxide (from 0.05 nM to 1 nM with a detection limit of 0.05 ± 0.01 nM. The apparent Michaelis-Menten constant (Kmapp was calculated to be 0.85 ± 0.1 nM. Thus, the modified electrode could be applied as a third generation biosensor with high sensitivity, long-term stability and low detection limit.

  2. Comparative study of the oxidation behavior of sulfur-containing amino acids and glutathione by electrochemistry-mass spectrometry in the presence and absence of cisplatin.

    Science.gov (United States)

    Zabel, Robert; Weber, Günther

    2016-02-01

    Small sulfur-containing compounds are involved in several important biochemical processes, including-but not limited to-redox regulation and drug conjugation/detoxification. While methods for stable redox pairs of such compounds (thiols/disulfides) are available, analytical data on more labile and short-lived redox intermediates are scarce, due to highly challenging analytical requirements. In this study, we employ the direct combination of reagentless electrochemical oxidation and mass spectrometric (EC-MS) identification for monitoring oxidation reactions of cysteine, N-acetylcysteine, methionine, and glutathione under simulated physiological conditions (pH 7.4, 37 °C). For the first time, all theoretically expected redox intermediates-with only one exception-are detected simultaneously and in situ, including sulfenic, sulfinic, and sulfonic acids, disulfides, thiosulfinates, thiosulfonates, and sulfoxides. By monitoring the time/potential-dependent interconversion of sulfur species, mechanistic oxidation routes are confirmed and new reactions detected, e.g., sulfenamide formation due to reaction with ammonia from the buffer. Furthermore, our results demonstrate a highly significant impact of cisplatin on the redox reactivity of sulfur species. Namely, the amount of thiol oxidation to sulfonic acid via sulfenic and sulfinic acid intermediates is diminished for glutathione in the presence of cisplatin in favor of the disulfide formation, while for N-acetylcysteine the contrary applies. N-acetylcysteine is the only ligand which displays enhanced oxidation currents upon cisplatin addition, accompanied by increased levels of thiosulfinate and thiosulfonate species. This is traced back to thiol reactivity and highlights the important role of sulfenic acid intermediates, which may function as a switch between different oxidation routes.

  3. Direct Electrochemistry of Hemoglobin on TiO2 Cavities Array%血红蛋白在二氧化钛球腔阵列上的直接电化学研究

    Institute of Scientific and Technical Information of China (English)

    周宇; 周丽娟; 孙磊; 尹凡

    2011-01-01

    采用Langmuir—Blodgett术和溶胶-凝胶(sol—gel)法在氧化铟锡(ITO)表面制备了TiO2球腔阵列.研究了TiO2球腔阵列的电化学性质,结果表明:所制备的TiO2球腔阵列具有微电极阵列特性.将血红蛋白(Hb)直接吸附在TiO2球腔阵列内部,制备过氧化氢(H2O2)生物传感器.修饰电极对过氧化氢(H2O2)的电流响应快速稳定、重现性和选择性较好,在9.00×10^-7~4.44×10^-4mol/L范围内H2O2浓度与响应电流呈现良好的线性关系,其检出限为3.12×10^-7mol/L,米氏常数为0.138mmol/L.%The TiO2 cavities array was fabricated on indium-tin oxide electrode surface by using Lang-muir-Blodgett technique and sol-gel technique. The electrochemistry property of TiO2 cavities array was investigated. The result showed that TiO2 cavities array had the property of microelectrode arrays. An amperometric biosensor for detection of H202 was prepared by adsorbing hemoglobin(Hb) in TiO2 cavities directly. In pH 7.0 phosphate buffer, the CV curve of Hb/TiO2 cavities array electrode showed a pair of reversible redox peaks, the catholic and anodic peak appeared at 0.042 and 0.127V, its direct electron transfer rate was 2.95s^-1. The amperometric response of the biosensor possessed properties of speediness, good stability, reproducibility, and selectivity. Under the optimal conditions, the calibration curve was linear in the range of 9.00×10^-7-4.44×10^-4 mol/L for H2O2 concentration with a detection limit of 3.12×10^-7 mol/L and the apparent Michaelis-Menten constant for HRP modified electrode was 0.138 mmol/L.

  4. 32 CFR 37.1220 - Applied research.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Applied research. 37.1220 Section 37.1220... REGULATIONS TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1220 Applied research... technology such as new materials, devices, methods and processes. It typically is funded in...

  5. Autobiographic Narratives as Data in Applied Linguistics

    Science.gov (United States)

    Pavlenko, Aneta

    2007-01-01

    In the past decade, language memoirs, linguistic autobiographies, and learners' journals and diaries have become a popular means of data collection in applied linguistics. It is not always clear however how one should go about analyzing these data. The aim of this paper is to offer a critical review of analytical frameworks applied to second…

  6. Child Participant Roles in Applied Linguistics Research

    Science.gov (United States)

    Pinter, Annamaria

    2014-01-01

    Children's status as research participants in applied linguistics has been largely overlooked even though unique methodological and ethical concerns arise in projects where children, rather than adults, are involved. This article examines the role of children as research participants in applied linguistics and discusses the limitations of…

  7. Applied Linguistics in Its Disciplinary Context

    Science.gov (United States)

    Liddicoat, Anthony J.

    2010-01-01

    Australia's current attempt to develop a process to evaluate the quality of research (Excellence in Research for Australia--ERA) places a central emphasis on the disciplinary organisation of academic work. This disciplinary focus poses particular problems for Applied Linguistics in Australia. This paper will examine Applied Linguistics in relation…

  8. Situations of Applied Psycholinguistics in China

    Institute of Scientific and Technical Information of China (English)

    陈雪

    2007-01-01

    Numerous studies related to applied psycholinguistics in China have been published in the past two decades. So the present study reviewed the situations of applied psycholinguistics and by discussing the results, existing problems are dipped and suggestions for further research are proposed.

  9. Applied technology section. Monthly report, March 1994

    Energy Technology Data Exchange (ETDEWEB)

    Buckner, M.R.

    1994-04-20

    This is a monthly report giving the details on research currently being conducted at the Savannah River Technology Center. The following are areas of the research, engineering modeling and simulation, applied statistics, applied physics,experimental thermal hydraulics,and packaging and transportation.

  10. Applied Mathematics Should Be Taught Mixed.

    Science.gov (United States)

    Brown, Gary I.

    1994-01-01

    Discusses the differences between applied and pure mathematics and provides extensive history of mixed mathematics. Argues that applied mathematics should be taught allowing for speculative mathematics, which involves breaking down a given problem into simpler parts until one arrives at first principles. (ASK)

  11. Applied Linguistics: The Challenge of Theory

    Science.gov (United States)

    McNamara, Tim

    2015-01-01

    Language has featured prominently in contemporary social theory, but the relevance of this fact to the concerns of Applied Linguistics, with its necessary orientation to practical issues of language in context, represents an ongoing challenge. This article supports the need for a greater engagement with theory in Applied Linguistics. It considers…

  12. Coming of Age in Applied Linguistics.

    Science.gov (United States)

    Bialystok, Ellen

    1998-01-01

    Argues that further progress in applied linguistics and second-language acquisition will be achieved through collaboration with researchers in other fields. Three examples of research problems are provided that would profit from collaboration with applied linguists: the definition of language proficiency, the neural basis of language functioning,…

  13. Recent Developments in Applied Probability and Statistics

    CERN Document Server

    Devroye, Luc; Kohler, Michael; Korn, Ralf

    2010-01-01

    This book presents surveys on recent developments in applied probability and statistics. The contributions include topics such as nonparametric regression and density estimation, option pricing, probabilistic methods for multivariate interpolation, robust graphical modelling and stochastic differential equations. Due to its broad coverage of different topics the book offers an excellent overview of recent developments in applied probability and statistics.

  14. Active system monitoring applied on wind turbines

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad; Parbo, Henrik

    2009-01-01

    A concept for active system monitoring (ASM) applied on wind turbines is presented in this paper. The concept is based on an injection of a small periodic auxiliary signal in the system. An investigation of the signature from the auxiliary input in residual (error) signals can then be applied...

  15. Effectiveness of Investment in Applied Horticultural Research

    NARCIS (Netherlands)

    Wustman, R.; Putter, de H.; Achterbosch, T.J.; Adamicki, F.

    2005-01-01

    A study on the cost benefit analysis of applied horticultural research was carried out in two EU Member States: the Netherlands and Poland. Four crops were selected for the study; two fruit crops ¿ apple and pear and two vegetable crops ¿ carrot and onion. A developed spreadsheet model was applied t

  16. History and theory in "applied ethics".

    Science.gov (United States)

    Beauchamp, Tom L

    2007-03-01

    Robert Baker and Laurence McCullough argue that the "applied ethics model" is deficient and in need of a replacement model. However, they supply no clear meaning to "applied ethics" and miss most of what is important in the literature on methodology that treats this question. The Baker-McCullough account of medical and applied ethics is a straw man that has had no influence in these fields or in philosophical ethics. The authors are also on shaky historical grounds in dealing with two problems: (1) the historical source of the notion of "practical ethics" and (2) the historical source of and the assimilation of the term "autonomy" into applied philosophy and professional ethics. They mistakenly hold (1) that the expression "practical ethics" was first used in a publication by Thomas Percival and (2) that Kant is the primary historical source of the notion of autonomy as that notion is used in contemporary applied ethics.

  17. Peripherally applied opioids for postoperative pain

    DEFF Research Database (Denmark)

    Nielsen, B N; Henneberg, S W; Schmiegelow, K;

    2015-01-01

    BACKGROUND: Opioids applied peripherally at the site of surgery may produce postoperative analgesia with few side effects. We performed this systematic review to evaluate the analgesic effect of peripherally applied opioids for acute postoperative pain. METHODS: We searched PubMed (1966 to June...... 2013), Embase (1980 to June 2013), and the Cochrane Central Register of Controlled Trials (The Cochrane Library 2013, Issue 6). Randomized controlled trials investigating the postoperative analgesic effect of peripherally applied opioids vs. systemic opioids or placebo, measured by pain intensity...... difference -5 mm, 95% CI: -7 to -3) for peripherally applied opioids vs. placebo and statistically significant increased time to first analgesic (mean difference 153 min, 95% CI: 41-265). When preoperative inflammation was reported (five studies), peripherally applied opioids significantly improved...

  18. Encyclopedia of applied and computational mathematics

    CERN Document Server

    2015-01-01

    EACM is a comprehensive reference work covering the vast field of applied and computational mathematics. Applied mathematics itself accounts for at least 60 per cent of mathematics, and the emphasis on computation reflects the current and constantly growing importance of computational methods in all areas of applications. EACM emphasizes the strong links of applied mathematics with major areas of science, such as physics, chemistry, biology, and computer science, as well as specific fields like atmospheric ocean science. In addition, the mathematical input to modern engineering and technology form another core component of EACM.

  19. Concept analysis of culture applied to nursing.

    Science.gov (United States)

    Marzilli, Colleen

    2014-01-01

    Culture is an important concept, especially when applied to nursing. A concept analysis of culture is essential to understanding the meaning of the word. This article applies Rodgers' (2000) concept analysis template and provides a definition of the word culture as it applies to nursing practice. This article supplies examples of the concept of culture to aid the reader in understanding its application to nursing and includes a case study demonstrating components of culture that must be respected and included when providing health care.

  20. Applied linguistics - a science of culture?

    Directory of Open Access Journals (Sweden)

    Benke, Gertraud

    2003-01-01

    Full Text Available In this article, the status of applied linguistics as discipline is questioned and problems of establishing it - and other newly formed scientific enterprises like cultural science - as disciplines are discussed. This discussion is contextualized using the author's own experience as applied linguist working in (the institutional structure of Austria. Secondly, applied linguistics is presented as complementing cultural science, with both exploring at times the same phenomena albeit under different perspectives and focussing on different levels of experience. Two examples of research involving such a joint interest with different foci are discussed.

  1. Applied Sciences—Connecting Theories with Practice

    Directory of Open Access Journals (Sweden)

    Takayoshi Kobayashi

    2011-09-01

    Full Text Available Applied sciences cover many interdisciplinary fields that put basic sciences to application and make big changes by taking the one not-so-small step from “knowing how” to “knowing how-to”, the serendipity of which is often intriguing. Applied sciences are so deeply entrenched in almost all aspects of our daily lives. To provide an advanced forum for scholars all over the world to discuss and communicate the cutting-edge development in this field, on behalf of the Editorial Board members, I am honored to introduce Applied Sciences, a scholarly, peer-reviewed open access journal. [...

  2. ON THE EVOLUTION OF APPLIED MATHEMATICS

    Institute of Scientific and Technical Information of China (English)

    林家翘

    2003-01-01

    The recent trend in the application of mathematics to biological sciences is discussed in historical perspective. It is suggested that this new development should be regarded as a natural evolution of applied mathematics in the expansion of its scope. The mathematical concepts and methods to be used are not expected to be substantially different from those used in traditional applied mathematics. For illustration, we sketch an application of the kinetic theory of the study of dissipative systems to the study of the structure and function of protein molecules. The traditional concepts and methods of statistical physics can be successfully applied to yield predictions for comparison with empirical data.

  3. Advanced surface technology a holistic view on the extensive and intertwined world of applied surface engineering

    CERN Document Server

    Moller, Per

    2013-01-01

    These two volumes serve as an inclusive and practical reference in manufacturing as well as a comprehensive text for university-level course work. Before delving into the variety of conventional and emerging surface finishing processes available to the 21st century practitioner, the authors cover the principles behind the processes, including wear and other mechanical properties, corrosion and electrochemistry. Throughout, the material also covers testing, property measurement and a generic introduction to basically all surface relevant characterization techniques, keyed to the specific process and application under discussion.

  4. 1st Applied Electromagnetic International Conference

    CERN Document Server

    Othman, Mohd; Aziz, Mohamad; Malek, Mohd

    2015-01-01

    In this book, experts from academia and industry present the latest advances in scientific theory relating to applied electromagnetics and examine current and emerging applications particularly within the fields of electronics, communications, and computer technology. The book is based on presentations delivered at APPEIC 2014, the 1st Applied Electromagnetic International Conference, held in Bandung, Indonesia in December 2014. The conference provided an ideal platform for researchers and specialists to deliver both theoretically and practically oriented contributions on a wide range of topics relevant to the theme of nurturing applied electromagnetics for human technology. Many novel aspects were addressed, and the contributions selected for this book highlight the relevance of advances in applied electromagnetics to a variety of industrial engineering problems and identify exciting future directions for research.

  5. ICT for AQA applied as single award

    CERN Document Server

    Wilson, Barbara

    2007-01-01

    This book has been written specifically for teachers and students following AQA's Applied AS ICT specification and covers the key elements of the units of the course, including the coursework requirements.

  6. Center for Food Safety and Applied Nutrition

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for Food Safety and Applied Nutrition, known as CFSAN, is one of six product-oriented centers, in addition to a nationwide field force, that carry out the...

  7. Applied physics: The virtues of tiling

    Science.gov (United States)

    Fratzl, Peter

    2014-12-01

    A cracked metal film on an elastic substrate has been shown to provide ultrahigh sensitivity in detecting mechanical vibrations. The result draws inspiration from principles of tiling that apply to many biological systems. See Letter p.222

  8. Computational optimization techniques applied to microgrids planning

    DEFF Research Database (Denmark)

    Gamarra, Carlos; Guerrero, Josep M.

    2015-01-01

    appear along the planning process. In this context, technical literature about optimization techniques applied to microgrid planning have been reviewed and the guidelines for innovative planning methodologies focused on economic feasibility can be defined. Finally, some trending techniques and new...

  9. 2nd Applied Electromagnetic International Conference

    CERN Document Server

    Sulaiman, Hamzah; Othman, Mohd; Aziz, Mohamad; Malek, Mohd

    2017-01-01

    In this book, experts from academia and industry present the latest advances in scientific theory relating to applied electromagnetics and examine current and emerging applications particularly within the fields of electronics, communications, and computer technology. The book is based on presentations delivered at APPEIC 2015, the 2nd Applied Electromagnetic International Conference, held in Krabi, Thailand in December 2015. The conference provided an ideal platform for researchers and specialists to deliver both theoretically and practically oriented contributions on a wide range of topics relevant to the theme of nurturing applied electromagnetics for human technology. Many novel aspects were addressed, and the contributions selected for this book highlight the relevance of advances in applied electromagnetics to a variety of industrial engineering problems and identify exciting future directions for research.

  10. Applying Change of Variable to Calculus Problems

    Science.gov (United States)

    Kachapova, Farida; Kachapov, Ilias

    2011-01-01

    This article describes the technique of introducing a new variable in some calculus problems to help students master the skills of integration and evaluation of limits. This technique is algorithmic and easy to apply.

  11. Study on the direct electrochemistry of Myoglobin based on Ag2 S-MWNTs nanocomposites%基于Ag2 S-MWNTs的肌红蛋白直接电化学研究

    Institute of Scientific and Technical Information of China (English)

    史智锋; 贺慧; 马李思思

    2014-01-01

    Ag2 S-MWNTs nanoconposites was prepared and then a Mb-Ag2 S-MWNTs-CHIT/GCE was fabricated. Based on the fabri-cated Mb-Ag2 S-MWNTs-CHIT/GCE,the direct electrochemistry and electrocatalytic properties of the immobilized Mb were investi-gated. Scanning electron microscopic and Transmission electron microscopic were used to characterize the morphology of the Ag2 S-MWNTs. Cyclic voltammetry and amperometry were used for studying the electrochemical behaviors of Mb. Uniform and stable Ag2 S was growing at the MWNTs surface,and the fabricated electrode showed a well-defined and quasi-reversible redox peaks and good electrocatalytic ability for hydrogen peroxide( H2 O2 ) reduction. The resulting modified electrode could detect H2 O2 in a linear range of 1. 0 × 10-6 ~2. 5 × 10-4 mol·L-1 and the detection limit was 3 × 10-7 mol·L-1 at a signal-to-noise ratio of 3. Ag2 S-MWNTs in-creased the direct electron transfer rate dramatically and the modified electrode can provide a good platform for the investigation of the third generation biosensors.%制备了硫化银-多壁碳纳米管( Ag2 S-MWNTs)纳米复合材料,构置了Mb-Ag2 S-MWNTs-CHIT/GCE,并研究了肌红蛋白( Mb)在该修饰电极上的直接电化学和电催化行为。采用扫描电镜和透射电镜表征了Ag2 S-MWNTs的形貌,利用循环伏安法对Mb的电化学行为进行研究。 Ag2 S能够均一、稳定的在MWNTs表面生长,所构置的修饰电极在PBS中出现一对峰形良好的、准可逆的氧化还原峰,并对过氧化氢( H2 O2)表现出良好的电催化作用,测定H2O2的线性范围为1.0×10-6~2.5×10-4 mol·L-1,检出限为3×10-7 mol·L-1(S/N=3)。 Ag2 S-MWNTs纳米复合材料能显著提高氧化还原蛋白质(酶)的直接电子传递速率,所构置的修饰电极可为制备基于蛋白质(酶)的第三代电化学生物传感器提供一良好的研究平台。

  12. 13th European Conference on Applied Superconductivity

    CERN Document Server

    2017-01-01

    EUCAS is a worldwide forum for scientists and engineers, and provides an ideal platform to share knowledge and the most recent advances in all areas of applied superconductivity: from large-scale applications to miniature electronics devices, with a traditional focus on advanced materials and conductors. The broad scope is at the same time a challenge and an opportunity to foster novel, inter-disciplinary approaches and promote cross-fertilization among the various fields of applied superconductivity.

  13. ECONOMIC ETHICS: APPLIED AND PROFESSIONAL CHARACTER

    Directory of Open Access Journals (Sweden)

    Ella Gordova

    2012-01-01

    Full Text Available In given article economic ethics are considered as set of norms of behavior of the businessman, the requirements shown by a cultural society to its style of work, to character of dialogue between participants of business, to their social shape. The conclusion becomes that economic ethics have applied character in relation to theoretical, to obschenormativnoy ethics, hence, represent section of applied ethics. On the other hand, the specific standard maintenance characterizes economic ethics as ethics professional.

  14. Association Rules Applied to Intrusion Detection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We discuss the basic intrusion detection techniques, and focus on how to apply association rules to intrusion detection. Begin with analyzing some close relations between user's behaviors, we discuss the mining algorithm of association rules and apply to detect anomaly in IDS. Moreover, according to the characteristic of intrusion detection, we optimize the mining algorithm of association rules, and use fuzzy logic to improve the system performance.

  15. Industrial and Applied Mathematics in China

    CERN Document Server

    Li, Ta-Tsien

    2009-01-01

    This new volume introduces readers to the current topics of industrial and applied mathematics in China, with applications to material science, information science, mathematical finance and engineering. The authors utilize mathematics for the solution of problems. The purposes of the volume are to promote research in applied mathematics and computational science; further the application of mathematics to new methods and techniques useful in industry and science; and provide for the exchange of information between the mathematical, industrial, and scientific communities.

  16. Computers in Some Branches of Applied Physiology .

    Directory of Open Access Journals (Sweden)

    S.S. Verma

    1994-04-01

    Full Text Available This paper reviews the applications of computers in the evaluation of different types of problems occuring in some branches of applied physiology. The recent applications of computers to perform advanced multivariate regression analysis for developing regression models in applied physiology are also highlighted. The regression models are practical significance for screening personnel in defence services, mines, industrial works, sports and the like.

  17. Industrial and applied mathematics in China

    CERN Document Server

    Li,Tatsien

    2014-01-01

    This new volume introduces readers to the current topics of industrial and applied mathematics in China, with applications to material science, information science, mathematical finance and engineering. The authors utilize mathematics for the solution of problems. The purposes of the volume are to promote research in applied mathematics and computational science; further the application of mathematics to new methods and techniques useful in industry and science; and provide for the exchange of information between the mathematical, industrial, and scientific communities.

  18. The Bakhtin Circle and Applied Linguistics

    Directory of Open Access Journals (Sweden)

    Newton Duarte Molon

    2012-11-01

    Full Text Available This article aims at presenting the relations between the theoretical formulations of the Bakhtin Circle and the current discussion on the scope of the so called Applied Linguistics (AL. In order to do that, we will briefly outline the history of AL, present the main conceptions of the Bakhtin Circle‟s thought, and build possible dialogues between the theoretical formulations of the Russian thinkers and the main issues of the current debate in Applied Linguistics.

  19. FEEDBACK LINEARISATION APPLIED ON A HYDRAULIC

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik C.;

    2005-01-01

    Generally most hydraulic systems are intrensically non-linear, why applying linear control techniques typically results in conservatively dimensioned controllers to obtain stable performance. Non-linear control techniques have the potential of overcoming these problems, and in this paper the focus...... is on developing and applying several different feedback linearisation (FL) controllers to the individual servo actuators in a hydraulically driven servo robot to evaluate and compare their possiblities and limitations. This is done based on both simulation and experimental results....

  20. [What did bachelard mean by "applied rationalism" ?].

    Science.gov (United States)

    Tiles, Mary

    2013-01-01

    Bachelard was concerned with the processes whereby scientific knowledge is acquired, including the activity of knowing subjects. He did not equate reasoning with logic but rather argued that reasoning resulted from the use of mathematics in organizing both thought and experimental practices, which is why he conceived science as applied mathematics. This had material and technical implications, for Bachelard was concerned with the element of reason inherent in technical materialism as well as the concrete reality inherent in applied rationalism.

  1. Single Entity Electrochemistry Progresses to Cell Counting.

    Science.gov (United States)

    Gooding, J Justin

    2016-10-10

    Red blood cells have been counted in an electrochemical collision experiment recently described by Compton and co-workers. As a cell collides with the electrode it lyses and a current is observed from the reduction of oxygen from within the cell.

  2. Electrochemistry of ABTS at Glassy Carbon Electrodes

    Institute of Scientific and Technical Information of China (English)

    Han Zeng; Zhi-qiang Tang; Ling-wen Liao; Jing Kang; Yan-xia Chen

    2011-01-01

    The electrochemical and the mass transport behavior of ABTS2-/ABTS- (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate)) redox couple at glassy carbon electrode (GCE) in phosphate buffer solution (PBS,pH=4.4) is studied in detail by cyclic voltammetry combined with rotating disk electrode system.From the i-E curves recorded at different electrode rotating rate,rate constant,and transfer coefficient for ABTS 2-(≒)ABTS-+e reaction at GCE electrode and the diffusion coefficient of ABTS2- in PBS are estimated to be 4.6× 10-3 cm/s,0.28,and 4.4× 10-6 cm2/s,respectively.The transfer coefficient with a value of ca.0.28 differs largely from the value of 0.5 that is always assumed in the literature.The origins for the difference of the rate constant determined and the challenges for estimating the standard rate constant are discussed.The performance for such ABTS2- mediated bio-cathode toward oxygen reduction reaction is discussed according to the over-potential drop as well as current output limit associated with the charge transfer kinetics of ABTS2- (≒)ABTS- +e redox reaction and/or the mass transport effect.

  3. 2015 CEC Annual Workshop on Electrochemistry

    Science.gov (United States)

    2015-12-30

    on using Density Functional Theory (DFT) to probe the electronic structure of photo- and electro-catalysts used in the Haber-Bosch process and water ...strain effect from the ligand effect. NiTi phase transitions with temperature , but it can also be maintained at room temperature in three different ...features technical presentations and posters from several different perspectives covering areas ranging from electrocatalysis, electrochemical sensors

  4. Pyrolytic 3D Carbon Microelectrodes for Electrochemistry

    DEFF Research Database (Denmark)

    Hemanth, Suhith; Caviglia, Claudia; Amato, Letizia;

    2016-01-01

    by pyrolysis at 900ºC for 1h was developed. With this process, microelectrode chips with a three electrode configuration were fabricated and characterized with cyclic voltammetry (CV) using a 10mM potassium ferri-ferrocyanide redox probe in a custom made batch system with magnetic clamping. The 3D pyrolytic...

  5. Hybrid electronics and electrochemistry with conjugated polymers.

    Science.gov (United States)

    Inganäs, Olle

    2010-07-01

    In this critical review, we discuss the history and development of polymer devices wherein manipulation of the electronic conductivity by electrochemical redox processes in a conjugated polymer is used to form new functions. The devices employed are an electrochemical transistor, an electrolyte-gated field-effect transistor and light-emitting electrochemical cells, all of which combine doping/undoping of a conjugated polymer with modification of electronic transport (130 references).

  6. Pyrolytic 3D Carbon Microelectrodes for Electrochemistry

    DEFF Research Database (Denmark)

    Hemanth, Suhith; Caviglia, Claudia; Amato, Letizia

    2016-01-01

    electrochemical activity, chemical stability, and ease in surface functionalization [1]. The most common carbon microfabrication techniques (i.e. screen printing) produce two-dimensional (2D) electrodes, which limit the detection sensitivity. Hence several 3D microfabrication techniques have been explored......This work presents the fabrication and characterization of multi-layered three-dimensional (3D) pyrolysed carbon microelectrodes for electrochemical applications. For this purpose, an optimized UV photolithography and pyrolysis process with the negative tone photoresist SU-8 has been developed...... carbon [2]. This process enables fabrication of 2D and 3D electrodes with possibility for tailoring ad-hoc designs and unique sensitivities for specific applications. Due to this, pyrolysed carbon is becoming increasingly attractive for numerous applications, such as novel sensors and scaffolds for cell...

  7. Fundamental Material Properties Underlying Solid Oxide Electrochemistry

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Hansen, Karin Vels; Holtappels, Peter;

    2012-01-01

    such as “this is the rate limiting step of H2 oxidation in a Ni-zirconia cermet electrode...” will ever be found because the actual electrode properties are so dependent on the fabrication and operation history of the electrode. This does not mean, however, that deep knowledge of mechanisms of specific SOC...... in the TPB region. Also, segregations to the surfaces and interfaces of the electrode materials, which may affect the electrode reaction mechanism, are very dependent on the exact history of fabrication and operation. The positive effects of even small concentrations of nanoparticles in the electrodes may...

  8. Electrochemistry of Some New Alkaline Battery Electrodes

    Science.gov (United States)

    1976-02-01

    Charging Efficiencies for AFAPL and Aircraft Cells 20 4. Slow Scan Cyclic Voltametry of 30% KOH Solutions at the Nickel Hydroxide Electrode 21 5...in our laboratory has offered a partial explanation for this effect. Using cyclic voltametric studies it was revealed that presence of cobalt...observed between charge and discharge peak potentials. In the presence of Ca. 10% cobalt hydroxide, this difference is only 75 mV. The cyclic voltametric

  9. Organic Electrochemistry in Aluminum Chloride Melts.

    Science.gov (United States)

    1976-08-15

    Cyclic voltametry revealed adamantane and l-methyladamanta1ie to be electroactive at a tungsten electrode * well within the background limits of molten...diphenylmethane. Coulometry cyclic voltametry and ring-disc electrode studies were carried out to elucidate a mechanism for the reaction. It was shown that...the viscosity was found to be 25 cp and the • I conductivity, 3 x 1O~ ohm~ cm ’. A variety of electrode materials were surveyed via cyclic voltaninetry

  10. Applications of Scanning Tunneling Microscopy to Electrochemistry

    Science.gov (United States)

    1988-10-28

    3 electrode voltametry to be performed (61). Itaya ot. &l. have gained similar capabilities by modifying their aforementioned STH (Itaya, K.; Higaki...vs. NHE. f - 2.5 kHz ), and were imaged (at nanometer resolution) before and after the electrochemical treatment. The cyclic voltammograms in the H

  11. Encyclopedia of electrochemistry. Vol. 10. Modified electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Bard, A.J. [Texas Univ., Austin, TX (United States). Dept. of Chemistry; Stratmann, M. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany); Rubinstein, I. [Weizmann Institute of Science, Rehovot (Israel). Dept. of Materials and Interfaces; Fujihira, Masamichi [Tokyo Institute of Technology, Yokohama (Japan). Dept. of Biomolecular Engineering; Rusling, J.F. (eds.) [Connecticut Univ., Storrs, CT (United States). Dept. of Chemistry, U-60]|[Connecticut Univ., Storrs, CT (United States). Dept. of Pharmacology

    2007-07-01

    This volume contains the following topics: 1. Preparation of monolayer modified electrodes; 2. Layer-by-layer assemblies of thin films on electrodes; 3. Epitaxial electrochemical growth; 5. Other films; 6. Ex-situ methods; 7. In-situ methods; 8. Electron transfer; 9. Charge transport in polymer-modified electrodes; 10. Electrochemical reactions on modified electrodes; 11. Redox-active dendrimers in solution and as films on surfaces; 12. Electrochemical formation of organic thin films; 13. Electron transfer and transport in ordered enzyme layers.

  12. Pattern Electrodes for Studying SOFC Electrochemistry

    NARCIS (Netherlands)

    Patel, H.C.; Biradar, N.; Venkataraman, V.; Aravind, P.V.

    2013-01-01

    Pattern anodes can be used to localize reactions and study individual processes like charge transfer, adsorption, diffusion etc. Ceria and Nickel (Ni) pattern anodes were fabricated with the same dimensions with Triple phase boundary (TPB) lengths of 0.2707 m/cm2. Electrochemical Impedance Spectrosc

  13. In-situ SEM electrochemistry and radiolysis

    DEFF Research Database (Denmark)

    Møller-Nilsen, Rolf Erling Robberstad; Norby, Poul

    Electron microscopy is a ubiquitous technique to see effects which are too small to see with traditional optical microscopes. Recently it has become possible to also image liquid samples by encapsulating them from the vacuum of the microscope and a natural evolution from that has been to include...... microelectrodes on the windows to enable studies of electrohcemical processes. In this way it is possible to perform in-situ electrochemical experiments such as electroplating and charge and discharge analysis of battery electrodes. In a typical liquid cell, electrons are accelerated to sufficiently high energies...... to traverse a thin window made by a silicon nitride membrane, and interact with the sample immersed in liquid. In transmission electron microscopy (TEM) the majority of the electrons continue through the sample to form an image. In scanning electron microscopy (SEM) a fraction of the electrons...

  14. Electrochemistry at Liquid-Lidid Interfaces

    OpenAIRE

    Gulaboski, Rubin

    2012-01-01

    Liquid-liquid interface is a natural border separating two solutions with different features. In this lecture, the phenomena of ion transfer at the Liquid-Liquid interfaces are elaborated, while hints are given to determine the themrodynamic and kinetic parameters relevant to the ion transfer processes.

  15. Nano-scale effects in electrochemistry

    DEFF Research Database (Denmark)

    Meier, J.; Schiøtz, Jakob; Liu, Ping;

    2004-01-01

    We report combined scanning tunneling microscopy and electrochemical reactivity measurements on individual palladium nanoparticles supported on a gold surface. It is shown that the catalytic activity towards electrochemical proton reduction is enhanced by more than two orders of magnitude as the ...... by the thickness-variation of the support-induced strain at the surface of the palladium nanoparticles. (C) 2004 Elsevier B.V. All rights reserved....

  16. Electrochemistry and Electrochemical Methodology in Molten Salts.

    Science.gov (United States)

    1980-09-01

    similar conditions. A manuscript based on this work has been published in the Journal of the Electrochemical Society (34). 2) Melt and co-solvent As...Temperature Molten Salt," In "Proceedings of the 2nd International Symposium on Molten Salts," 3. Braunstein, Ed., published by The Electrochemical Society , in...Jones and L. G. Boxall, "Electrochemical Studies in Molten Chloroaluminates," Symposium on Fused Salt Tech- nology, Electrochemical Society Meeting

  17. Electrochemistry of polyamidoamine dendrimers ester gel electrolytes

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong; MO Zunli

    2004-01-01

    This paper described the first example of polyamidoamine dendrimers ester (PAMAM) used as a gel electrolyte with a short-chain polyethylene glycol (MPEG-400) as a plasticizer. The polymer films are solid and sticky. Background cyclic voltammetry (CV) shows a potential window between +0.7 and -0.7 V vs. Ag/AgCl. The voltammetry of ferrocene and 7,7,8,8-tetracyanoquinodimethane (TCNQ) indicates that diffusion coefficients are in the range of 10-a-10-9 cm2/s.Ionic conductivities are approximately 10-6 S/cm. Similar films using dimethyl sulfoxide (DMSO) as a plasticizer instead of MPEG-400 have demonstrated ionic conductivities of 10-4 S/cra and reversible voltammetry. However, UV spectrophotometry shows that 70% of the DMSO is lost under vacuum, indicating the difficulty in quantifying the DMSO content when exposed to vacuum.

  18. Electrochemistry of Water-Cooled Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Macdonald, Dgiby; Urquidi-Macdonald, Mirna; Pitt, Jonathan

    2006-08-08

    This project developed a comprehensive mathematical and simulation model for calculating thermal hydraulic, electrochemical, and corrosion parameters, viz. temperature, fluid flow velocity, pH, corrosion potential, hydrogen injection, oxygen contamination, stress corrosion cracking, crack growth rate, and other important quantities in the coolant circuits of water-cooled nuclear power plants, including both Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). The model is being used to assess the three major operational problems in Pressurized Water Reactors (PWR), which include mass transport, activity transport, and the axial offset anomaly, and provide a powerful tool for predicting the accumulation of SCC damage in BWR primary coolant circuits as a function of operating history. Another achievement of the project is the development of a simulation tool to serve both as a training tool for plant operators and as an engineering test-bed to evaluate new equipment and operating strategies (normal operation, cold shut down and others). The development and implementation of the model allows us to estimate the activity transport or "radiation fields" around the primary loop and the vessel, as a function of the operating parameters and the water chemistry.

  19. Applied regression analysis a research tool

    CERN Document Server

    Pantula, Sastry; Dickey, David

    1998-01-01

    Least squares estimation, when used appropriately, is a powerful research tool. A deeper understanding of the regression concepts is essential for achieving optimal benefits from a least squares analysis. This book builds on the fundamentals of statistical methods and provides appropriate concepts that will allow a scientist to use least squares as an effective research tool. Applied Regression Analysis is aimed at the scientist who wishes to gain a working knowledge of regression analysis. The basic purpose of this book is to develop an understanding of least squares and related statistical methods without becoming excessively mathematical. It is the outgrowth of more than 30 years of consulting experience with scientists and many years of teaching an applied regression course to graduate students. Applied Regression Analysis serves as an excellent text for a service course on regression for non-statisticians and as a reference for researchers. It also provides a bridge between a two-semester introduction to...

  20. [A critical review of applied criminology].

    Science.gov (United States)

    Vollbach, Alexander

    2016-01-01

    By reporting on a recent decision of the Regional Court (LG) of Marburg (Germany) calling attention to applied criminology, a concept still insufficiently considered in the administration of criminal justice, the paper argues that professional action in the execution of the sentence represents nothing else but applied criminology. Based on this assumption, the paper discusses practical diagnosis and correctional planning. Beyond that, the paper deals with the future of criminology. In the opinion of the author an important aspect for the future of criminology will be if it will be able to remain in touch with the world in which we live, as an independent empirical science. Applied criminology and its methodology constitute the link between science and practice.

  1. H-methods in applied sciences

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar

    2008-01-01

    The author has developed a framework for mathematical modelling within applied sciences. It is characteristic for data from 'nature and industry' that they have reduced rank for inference. It means that full rank solutions normally do not give satisfactory solutions. The basic idea of H...... with finding a balance between the estimation task and the prediction task. The name H-methods has been chosen because of close analogy with the Heisenberg uncertainty inequality. A similar situation is present in modelling data. The mathematical modelling stops, when the prediction aspect of the model cannot...... be improved. H-methods have been applied to wide range of fields within applied sciences. In each case, the H-methods provide with superior solutions compared to the traditional ones. A background for the H-methods is presented. The H-principle of mathematical modelling is explained. It is shown how...

  2. 2015 ICSA/Graybill Applied Statistics Symposium

    CERN Document Server

    Wang, Bushi; Hu, Xiaowen; Chen, Kun; Liu, Ray

    2016-01-01

    The papers in this volume represent a broad, applied swath of advanced contributions to the 2015 ICSA/Graybill Applied Statistics Symposium of the International Chinese Statistical Association, held at Colorado State University in Fort Collins. The contributions cover topics that range from statistical applications in business and finance to applications in clinical trials and biomarker analysis. Each papers was peer-reviewed by at least two referees and also by an editor. The conference was attended by over 400 participants from academia, industry, and government agencies around the world, including from North America, Asia, and Europe. Focuses on statistical applications from clinical trials, biomarker analysis, and personalized medicine to applications in finance and business analytics A unique selection of papers from broad and multi-disciplinary critical hot topics - from academic, government, and industry perspectives - to appeal to a wide variety of applied research interests All papers feature origina...

  3. A First Course in Applied Mathematics

    CERN Document Server

    Rebaza, Jorge

    2012-01-01

    Explore real-world applications of selected mathematical theory, concepts, and methods Exploring related methods that can be utilized in various fields of practice from science and engineering to business, A First Course in Applied Mathematics details how applied mathematics involves predictions, interpretations, analysis, and mathematical modeling to solve real-world problems. Written at a level that is accessible to readers from a wide range of scientific and engineering fields, the book masterfully blends standard topics with modern areas of application and provides the needed foundation

  4. Applying a Genetic Algorithm to Reconfigurable Hardware

    Science.gov (United States)

    Wells, B. Earl; Weir, John; Trevino, Luis; Patrick, Clint; Steincamp, Jim

    2004-01-01

    This paper investigates the feasibility of applying genetic algorithms to solve optimization problems that are implemented entirely in reconfgurable hardware. The paper highlights the pe$ormance/design space trade-offs that must be understood to effectively implement a standard genetic algorithm within a modem Field Programmable Gate Array, FPGA, reconfgurable hardware environment and presents a case-study where this stochastic search technique is applied to standard test-case problems taken from the technical literature. In this research, the targeted FPGA-based platform and high-level design environment was the Starbridge Hypercomputing platform, which incorporates multiple Xilinx Virtex II FPGAs, and the Viva TM graphical hardware description language.

  5. Fundamentals of applied probability and random processes

    CERN Document Server

    Ibe, Oliver

    2014-01-01

    The long-awaited revision of Fundamentals of Applied Probability and Random Processes expands on the central components that made the first edition a classic. The title is based on the premise that engineers use probability as a modeling tool, and that probability can be applied to the solution of engineering problems. Engineers and students studying probability and random processes also need to analyze data, and thus need some knowledge of statistics. This book is designed to provide students with a thorough grounding in probability and stochastic processes, demonstrate their applicability t

  6. Applied mathematics for science and engineering

    CERN Document Server

    Glasgow, Larry A

    2014-01-01

    Prepare students for success in using applied mathematics for engineering practice and post-graduate studies moves from one mathematical method to the next sustaining reader interest and easing the application of the techniques Uses different examples from chemical, civil, mechanical and various other engineering fields Based on a decade's worth of the authors lecture notes detailing the topic of applied mathematics for scientists and engineers Concisely writing with numerous examples provided including historical perspectives as well as a solutions manual for academic adopters

  7. Belbin's Team role theory applied to musicgroups

    OpenAIRE

    Qvick, Erik Robert, 1973-

    2015-01-01

    Can R Meredith Belbin´s team role theory be applied to applied to music groups? Could team role behavior have a impact on team work and group dynamic, and also on the success and productivity of a music group? This research analyzes the application of Belbin team role theory on three music groups consisting of Icelandic professional musicians to shed light on the possibilities of such relationships. The research examine the possibilities of relationships between team role behavior and it´s im...

  8. International Conference on Advances in Applied Mathematics

    CERN Document Server

    Hammami, Mohamed; Masmoudi, Afif

    2015-01-01

    This contributed volume presents some recent theoretical advances in mathematics and its applications in various areas of science and technology.   Written by internationally recognized scientists and researchers, the chapters in this book are based on talks given at the International Conference on Advances in Applied Mathematics (ICAAM), which took place December 16-19, 2013, in Hammamet, Tunisia.  Topics discussed at the conference included spectral theory, operator theory, optimization, numerical analysis, ordinary and partial differential equations, dynamical systems, control theory, probability, and statistics.  These proceedings aim to foster and develop further growth in all areas of applied mathematics.

  9. Applied orienting response research: some examples.

    Science.gov (United States)

    Tremayne, P; Barry, R J

    1990-01-01

    The development of orienting response (OR) theory has not been accompanied by many applications of the concept--most research still appears to be lab-based and "pure," rather than "applied." We present some examples from our own work in which the OR perspective has been applied in a wider context. These cover the exploration of processing deficits in autistic children, aspects of the "repression" of anxiety in elite athletes, and the locus of alcohol effects. Such applications of the OR concept in real-life situations seem a logical and, indeed, necessary step in the evolution of this area of psychophysiology.

  10. Applied mathematics for engineers and physicists

    CERN Document Server

    Pipes, Louis A

    2014-01-01

    One of the most widely used reference books on applied mathematics for a generation, distributed in multiple languages throughout the world, this text is geared toward use with a one-year advanced course in applied mathematics for engineering students. The treatment assumes a solid background in the theory of complex variables and a familiarity with complex numbers, but it includes a brief review. Chapters are as self-contained as possible, offering instructors flexibility in designing their own courses. The first eight chapters explore the analysis of lumped parameter systems. Succeeding topi

  11. SPSS for applied sciences basic statistical testing

    CERN Document Server

    Davis, Cole

    2013-01-01

    This book offers a quick and basic guide to using SPSS and provides a general approach to solving problems using statistical tests. It is both comprehensive in terms of the tests covered and the applied settings it refers to, and yet is short and easy to understand. Whether you are a beginner or an intermediate level test user, this book will help you to analyse different types of data in applied settings. It will also give you the confidence to use other statistical software and to extend your expertise to more specific scientific settings as required.The author does not use mathematical form

  12. Positive Behavior Support and Applied Behavior Analysis

    Science.gov (United States)

    Johnston, J. M.; Foxx, R. M.; Jacobson, J. W.; Green, G.; Mulick, J. A.

    2006-01-01

    This article reviews the origins and characteristics of the positive behavior support (PBS) movement and examines those features in the context of the field of applied behavior analysis (ABA). We raise a number of concerns about PBS as an approach to delivery of behavioral services and its impact on how ABA is viewed by those in human services. We…

  13. Exploring the Applied Arts. Publication No. 0041.

    Science.gov (United States)

    Sokolowski, Kathleen

    The program covered in this curriculum guide deals with applied arts, concentrating on the areas of advertising, fashion illustration, graphic design, cartooning, and textile design and decoration. These areas have been developed to give a hands-on experience to the students by simulating the working world and the student's place in it. Each area…

  14. Security, Privacy, and Applied Cryptography Engineering

    DEFF Research Database (Denmark)

    This book constitutes the refereed proceedings of the Second International Conference on Security, Privacy and Applied Cryptography Engineering held in Chennai, India, in November 2012. The 11 papers presented were carefully reviewed and selected from 61 submissions. The papers are organized...... and applications, high-performance computing in cryptology and cryptography in ubiquitous devices....

  15. Applied Mathematics, the Hans van Duijn way

    CERN Document Server

    Peletier, Mark A

    2012-01-01

    This is a former PhD student's take on his teacher's scientific philosophy. I describe a set of 'principles' that I believe are conducive to good applied mathematics, and that I have learnt myself from observing Hans van Duijn in action.

  16. Commentary: Narrative Ethnography as Applied Communication Research

    Science.gov (United States)

    Goodall, H. L., Jr.

    2004-01-01

    The breadth and heuristic merits of Harold (Buddy) Goodall's scholarship exemplify the teachings and influence of Gerald Phillips. One nominator applauds Goodall's leadership and dedication to furthering the visibility and utility of applied communication. Goodall's research is also widely used in other fields such as sociology and anthropology,…

  17. A Capstone Course in Applied Sociology.

    Science.gov (United States)

    Wallace, Richard Cheever

    1988-01-01

    Discusses the value of a capstone course in applied sociology as the culmination of the undergraduate sociology curriculum. Points out advantages of joint faculty-student projects for the course and presents the relative merits of two different formats: solo versus team projects. (Author/GEA)

  18. EG and G Mound Applied Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Sizemore, M.S. [EG and G MAT, Miamisburg, OH (United States)

    1990-11-01

    This paper reports on the robotics applications offered by EG and G Mound Applied Technologies. The robotics/automations applications discussed include explosive remote disassembly workcell, plasma spraying robot workcell, robotic assembly of ceramic headers, pyrotechnic automation workcell, general automation projects and robotic/vision inventory. This report consists of overheads only.

  19. Problems Portraying Migrants in Applied Linguistics Research

    Science.gov (United States)

    Block, David

    2010-01-01

    This paper is a very personal attempt to explore the problematics of portraying migrants in Applied Linguistics research. I begin with a discussion of identity, in particular what we might mean when we use the term, and from there I go on to explore its fundamental imprecision through an analysis of a census question about ethnicity. I then…

  20. Introduction: Conversation Analysis in Applied Linguistics

    Science.gov (United States)

    Sert, Olcay; Seedhouse, Paul

    2011-01-01

    This short, introductory paper presents an up-to-date account of works within the field of Applied Linguistics which have been influenced by a Conversation Analytic paradigm. The article reviews recent studies in classroom interaction, materials development, proficiency assessment and language teacher education. We believe that the publication of…

  1. Ideology in Applied Linguistics for Language Teaching

    Science.gov (United States)

    Waters, Alan

    2009-01-01

    It is contended that much of present-day applied linguistics for language teaching (ALLT) fails to mediate effectively, primarily because an ideological construction, emanating from a critical theory perspective, is too often imposed on everyday pedagogical practices. This has resulted in an exaggerated level of concern about the power imbalances…

  2. Plenary Speeches: Applied Linguists without Borders

    Science.gov (United States)

    Tarone, Elaine

    2013-01-01

    Until 1989, the American Association for Applied Linguistics (AAAL) could have been viewed as an interest group of the Linguistics Society of America (LSA); AAAL met in two designated meeting rooms as a subsection of the LSA conference. In 1991, I was asked to organize the first independent meeting of AAAL in New York City, with the help of…

  3. Center for Applied Linguistics, Washington DC, USA

    Science.gov (United States)

    Sugarman, Julie; Fee, Molly; Donovan, Anne

    2015-01-01

    The Center for Applied Linguistics (CAL) is a private, nonprofit organization with over 50 years' experience in the application of research on language and culture to educational and societal concerns. CAL carries out its mission to improve communication through better understanding of language and culture by engaging in a variety of projects in…

  4. Applying Servant Leadership in Today's Schools

    Science.gov (United States)

    Culver, Mary K.

    2009-01-01

    This book illustrates how the ideal of servant leadership can be applied in your school today. With real-life scenarios, discussions, and self assessments, this book gives practical suggestions to help you develop into a caring and effective servant leader. There are 52 scenarios in this book, focusing on situations as varied as: (1) Dealing with…

  5. Applied Hypergame Theory for Network Defense

    Science.gov (United States)

    2013-06-01

    attack. [5] Aigner, M. and M. Fromme . “A Game of Cops and Robbers”. Discrete Applied Mathematics, (8):1–12, 1984. [6] Alazzawe, Anis, Asad Nawaz, and...2013. URL http://refactoring.com/. [22] Freeman, Eric , Elisabeth Freeman, Kathy Sierra, and Bert Bates. Head First Design Patterns. O’Reilly Media

  6. Plant microbial fuel cell applied in wetlands

    NARCIS (Netherlands)

    Wetser, Koen; Liu, Jia; Buisman, Cees; Strik, David

    2015-01-01

    The plant microbial fuel cell (PMFC) has to be applied in wetlands to be able to generate electricity on a large scale. The objective of this PMFC application research is to clarify the differences in electricity generation between a Spartina anglica salt marsh and Phragmites australis peat soil

  7. Geostatistical methods applied to field model residuals

    DEFF Research Database (Denmark)

    Maule, Fox; Mosegaard, K.; Olsen, Nils

    consists of measurement errors and unmodelled signal), and is typically assumed to be uncorrelated and Gaussian distributed. We have applied geostatistical methods to analyse the residuals of the Oersted(09d/04) field model [http://www.dsri.dk/Oersted/Field_models/IGRF_2005_candidates/], which is based...

  8. Teaching Applied Ethics to the Righteous Mind

    Science.gov (United States)

    Murphy, Peter

    2014-01-01

    What does current empirically informed moral psychology imply about the goals that can be realistically achieved in college-level applied ethics courses? This paper takes up this question from the vantage point of Jonathan Haidt's Social Intuitionist Model of human moral judgment. I summarize Haidt's model, and then consider a variety of…

  9. Psycholinguistics in Applied Linguistics: Trends and Perspectives.

    Science.gov (United States)

    de Bot, Kees

    2000-01-01

    Discusses the relationship between the terms psycholinguistics and applied linguistics, and in the process explores key issues in multilingual processing, such as the structure of the bilingual lexicon, language choice in production and perception, and the language mode. (Author/VWL)

  10. Second Language Acquisition and Applied Linguistics.

    Science.gov (United States)

    Larsen-Freeman, Diane

    2000-01-01

    Discusses the second language acquisition (SLA) process and the differential success of second language learners. Examines the fundamental challenges that this characterization faces, and highlights the contributions SLA is capable of in the coming decade. Offers topics for a training and development of curriculum for future applied linguists from…

  11. Traditional and Applied Graduate Education: Special Challenges.

    Science.gov (United States)

    Powers, William G.; Love, Don E.

    1999-01-01

    Addresses the differences in philosophy and instruction methods while offering a means of complementary support. Discusses the traditional and applied communication graduate education models. Concludes that educators must establish and focus upon mutual respect for the commonalities held by the two approaches to graduate education and the support…

  12. Visualisation in Applied Learning Contexts: A Review

    Science.gov (United States)

    Twissell, Adrian

    2014-01-01

    This literature review explores visualisation within the context of learning in design, engineering and technology education. The investigation first defines visualisation, providing examples of activities that utilise visualisation skills within an applied field. Then exploration of the mental mechanisms of visualisation used to engage with those…

  13. Applied Biomechanics in an Instructional Setting

    Science.gov (United States)

    Hudson, Jackie L.

    2006-01-01

    Biomechanics is the science of how people move better, meaning more skillfully and more safely. This article places more emphasis on skill rather than safety, though there are many parallels between them. It shares a few features of the author's paradigm of applied biomechanics and discusses an integrated approach toward a middle school football…

  14. Applied programs at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This document overviews the areas of current research at Brookhaven National Laboratory. Technology transfer and the user facilities are discussed. Current topics are presented in the areas of applied physics, chemical science, material science, energy efficiency and conservation, environmental health and mathematics, biosystems and process science, oceanography, and nuclear energy. (GHH)

  15. Educating and Training Undergraduate Applied Statisticians.

    Science.gov (United States)

    Peres, Clovis A.; And Others

    1985-01-01

    A course on Applied Statistics, offered since 1978 at the Instituto de Matematica e Estatistica, Universidade de Sao Paulo, Brasil, is designed to educate statisticians at the bachelor's level for jobs in government statistical offices, industry, and business. (Author/LMO)

  16. Applying Lean on Agile Scrum Development Methodology

    Directory of Open Access Journals (Sweden)

    SurendRaj Dharmapal

    2015-11-01

    Full Text Available This journal introduces the reader to Agile and Lean concepts and provides a basic level of understanding of each process. This journal will also provide a brief background about applying Lean concepts on each phase of agile scrum methodology and summarize their primary business advantages for delivering value to customer.

  17. Applying Lean on Agile Scrum Development Methodology

    Directory of Open Access Journals (Sweden)

    SurendRaj Dharmapal

    2014-03-01

    Full Text Available This journal introduces the reader to Agile and Lean concepts and provides a basic leve l of understanding of each process. This journal will also provide a brief background about applying Lean concepts on each phase of agile scrum methodology and summarize their primary business advantages for delivering value to customer.

  18. Apply the Communicative Approach in Listening Class

    Institute of Scientific and Technical Information of China (English)

    Wang; changxue; Su; na

    2014-01-01

    Speaking and listening are the two obstacles in the process of our learning and they are also the most important abilities that we should possess. Communicative approach aims to the ability of learners’ communicative competence, thus apply the communicative approach in listening class is an effective way in English teaching procedure.

  19. Apply the Communicative Approach in Listening Class

    Institute of Scientific and Technical Information of China (English)

    Wang changxue; Su na

    2014-01-01

    Speaking and listening are the two obstacles in the process of our learning and they are also the most important abilities that we should possess. Communicative approach aims to the ability of learners’communicative competence, thus apply the communicative approach in listening class is an effective way in English teaching procedure.

  20. Applied Linguistics and Primary School Teaching

    Science.gov (United States)

    Ellis, Sue, Ed.; McCartney, Elspeth, Ed.

    2011-01-01

    Modern primary teachers must adapt literacy programmes and ensure efficient learning for all. They must also support children with language and literacy difficulties, children learning English as an additional language and possibly teach a modern foreign language. To do this effectively, they need to understand the applied linguistics research…

  1. Applying incentive sensitization models to behavioral addiction

    DEFF Research Database (Denmark)

    Rømer Thomsen, Kristine; Fjorback, Lone; Møller, Arne;

    2014-01-01

    The incentive sensitization theory is a promising model for understanding the mechanisms underlying drug addiction, and has received support in animal and human studies. So far the theory has not been applied to the case of behavioral addictions like Gambling Disorder, despite sharing clinical...

  2. State Key Laboratory of Applied Organic Chemistry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@The State Key Laboratory of Applied Organic Chemistry (SKLAOC) was founded in 1987 with the approval of the State Planning Commission. Professor Liu Zhongli is the director of the Laboratory and Professor Zhang Lihe, an academician of the Chinese Academy of Sciences, is the chairman of its academic committee. There are 30 faculty members, among them 21 are professors, working in the Laboratory.

  3. Applied groundwater modeling, 2nd Edition

    Science.gov (United States)

    Anderson, Mary P.; Woessner, William W.; Hunt, Randall J.

    2015-01-01

    This second edition is extensively revised throughout with expanded discussion of modeling fundamentals and coverage of advances in model calibration and uncertainty analysis that are revolutionizing the science of groundwater modeling. The text is intended for undergraduate and graduate level courses in applied groundwater modeling and as a comprehensive reference for environmental consultants and scientists/engineers in industry and governmental agencies.

  4. Applying critical thinking to college EFL teaching

    Institute of Scientific and Technical Information of China (English)

    刘迁

    2016-01-01

    In college EFL teaching, critical thinking has long been regarded as an advanced stage and skill of thinking. However, most Chinese EFL instructors stress language skills rather than critical thinking in class. this article mainly explores the strategies of applying critical thinking in college EFL teaching.

  5. A Course on Applied Linear Algebra.

    Science.gov (United States)

    Wang, Tse-Wei

    1989-01-01

    Provides an overview of a course, "Applied Linear Algebra," for teaching the concepts and the physical and geometric interpretations of some linear algebra topics. Describes the philosophy of the course, the computer project assignments, and student feedback. Major topics of the course are listed. (YP)

  6. Applying for Work Visas and Related Documentation

    Institute of Scientific and Technical Information of China (English)

    RICHARD; HOFFMANN

    2009-01-01

    Applying for an employment and residence certificate in China can be roughly broken down into four steps: the Alien Employment License applica- tion; the Employment Visa and Residence Permit Notification application; the Alien Employment Permit application; and the Residence Permit application.

  7. Newspaper Twitter: Applied Drama and Microblogging

    Science.gov (United States)

    Wotzko, Rebecca

    2012-01-01

    This paper discusses the use of applied drama within the microblogging platform "Twitter" as a method to increase students' social media and news literacy. Online news sites are increasingly using "Twitter" as a source for eyewitness accounts of events or public opinion. "Twitter" offers users a simple way to publicly…

  8. Controller modification applied for active fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob; Poulsen, Niels Kjølstad

    2014-01-01

    This paper is focusing on active fault detection (AFD) for parametric faults in closed-loop systems. This auxiliary input applied for the fault detection will also disturb the external output and consequently reduce the performance of the controller. Therefore, only small auxiliary inputs are used...

  9. Applied Creativity: The Creative Marketing Breakthrough Model

    Science.gov (United States)

    Titus, Philip A.

    2007-01-01

    Despite the increasing importance of personal creativity in today's business environment, few conceptual creativity frameworks have been presented in the marketing education literature. The purpose of this article is to advance the integration of creativity instruction into marketing classrooms by presenting an applied creative marketing…

  10. Applied mathematics in the world of complexity

    Directory of Open Access Journals (Sweden)

    Kazaryan V. P.

    2016-01-01

    Full Text Available In modern mathematics the value of applied research increases, for this reason, modern mathematics is initially focused on resolving the situation actually arose in this respect on a par with other disciplines. Using a new tool - computer systems, applied mathematics appealed to the new object: not to nature, not to society or the practical activity of man. In fact, the subject of modern applied mathematics is a problem situation for the actor-person, and the study is aimed at solving the material and practical problems. Developing the laws of its internal logic, mathematical science today covers various practices and makes them its own requirements, subjugating and organizing in their own way a subject of study. This math activity is influenced by such external factors as the condition of the actor-person; capacity of computers together with service professionals; characteristics of the object, and the external circumstances act as constituting the essence of the case and not as minor issues. The modern applied mathematics is becoming more and more similar to the engineering sciences, and the importance of mathematical modeling problem is rising. In the studies the author bases on the broader context of modern science, including works of philosophy and methodology, as well as mathematicians and specialists in the field of natural sciences.

  11. Applied Welding Technology. Technical Committee Report.

    Science.gov (United States)

    Idaho State Dept. of Education, Boise. Div. of Vocational Education.

    This Technical Committee Report prepared by industry representatives in Idaho lists the skills currently necessary for an employee in that state to obtain a job in applied welding technology, retain a job once hired, and advance in that occupational field. (Task lists are grouped according to duty areas generally used in industry settings, and are…

  12. The Master's Thesis in Applied Psychology Training.

    Science.gov (United States)

    Shultz, Kenneth S.; Kottke, Janet L.

    1996-01-01

    Recommends the inclusion of a master's thesis in industrial and organizational psychology programs. Argues that the thesis serves several critical educational purposes and is relevant to applied psychology. Offers suggestions for increasing the relationship between the educational requirement and the professional tasks. (MJP)

  13. Applying Social Psychological Concepts Outside the Classroom

    Science.gov (United States)

    Lakin, Jessica L.; Wichman, Aaron L.

    2005-01-01

    This article evaluates a writing assignment in which social psychology students gathered examples from outside the classroom (e.g., cartoons, movies) and analyzed them with course material. Compared to a control group, students who completed the assignment learned that it was easier to apply social psychology to the real world. A follow-up survey…

  14. A Primer on Disseminating Applied Quantitative Research

    Science.gov (United States)

    Bell, Bethany A.; DiStefano, Christine; Morgan, Grant B.

    2010-01-01

    Transparency and replication are essential features of scientific inquiry, yet scientific communications of applied quantitative research are often lacking in much-needed procedural information. In an effort to promote researchers dissemination of their quantitative studies in a cohesive, detailed, and informative manner, the authors delineate…

  15. Thermodynamic Laws Applied to Economic Systems

    Science.gov (United States)

    González, José Villacís

    2009-01-01

    Economic activity in its different manifestations--production, exchange, consumption and, particularly, information on quantities and prices--generates and transfers energy. As a result, we can apply to it the basic laws of thermodynamics. These laws are applicable within a system, i.e., in a country or between systems and countries. To these…

  16. Developing an Undergraduate Applied Learning Experience

    Directory of Open Access Journals (Sweden)

    Denise C. Nelson-Hurwitz

    2015-02-01

    Full Text Available To foster student development, critical thinking, and application skills among public health students at the University of Hawai‘i at Mānoa, a 3-course capstone series was developed as a key component of the public health Bachelor of Arts degree program. Over the course of 1.5 academic years students are actively involved in developing an interdisciplinary project proposal, then executing and presenting an independent, supervised, applied learning project. In the first course, students are introduced to a diverse range of public health projects and methods while working to develop their own project proposal- the foundation for the Applied Learning Experience. The project execution course is designed to allow students to execute their proposed applied learning projects. This experience focuses on the application and integration of public health knowledge, skills, and practice acquired during the bachelor’s degree course of study. Finally, students will be involved in reflecting on, finalizing, and sharing their completed projects in an undergraduate capstone seminar. Through implementation of this series, the program hopes to provide students with the opportunity to actively apply academic skills to real-world application.

  17. Political Economy in Applied Linguistics Research

    Science.gov (United States)

    Block, David

    2017-01-01

    This state-of-the-art review is based on the fundamental idea that political economy should be adopted as a frame for research and discussion in applied linguistics as part of a general social turn which has taken hold in the field over the past three decades. It starts with Susan Gal's (1989) early call for such a move in sociolinguistics and…

  18. Applied probability models with optimization applications

    CERN Document Server

    Ross, Sheldon M

    1992-01-01

    Concise advanced-level introduction to stochastic processes that frequently arise in applied probability. Largely self-contained text covers Poisson process, renewal theory, Markov chains, inventory theory, Brownian motion and continuous time optimization models, much more. Problems and references at chapter ends. ""Excellent introduction."" - Journal of the American Statistical Association. Bibliography. 1970 edition.

  19. Applied data mining for business and industry

    CERN Document Server

    Giudici, Paolo

    2009-01-01

    The increasing availability of data in our current, information overloaded society has led to the need for valid tools for its modelling and analysis. Data mining and applied statistical methods are the appropriate tools to extract knowledge from such data. This book provides an accessible introduction to data mining methods in a consistent and application oriented statistical framework, using case studies drawn from real industry projects and highlighting the use of data mining methods in a variety of business applications. Introduces data mining methods and applications.Covers classical and Bayesian multivariate statistical methodology as well as machine learning and computational data mining methods.Includes many recent developments such as association and sequence rules, graphical Markov models, lifetime value modelling, credit risk, operational risk and web mining.Features detailed case studies based on applied projects within industry.Incorporates discussion of data mining software, with case studies a...

  20. Applying Dairy Cow Behavior in Management Practice

    Institute of Scientific and Technical Information of China (English)

    YUAN Kai; LIU Zongping; WANG Zongyuan

    2009-01-01

    Applying dairy cow behavior in management practice is an effective way of improving cow health, welfare and performance. This paper first reviewed daily time budget and normal patterns of dairy cow behavior, and then discussed the influence of major management conditions and practices (such as competitive environments, stocking density, grouping strategies) on cow's feeding, lying and social behavior. Finally, new findings of using feeding behavior to predict disorders in transition period were addressed. It was suggested that dairy researchers and farmers should take advantage of related knowledge of dairy cow behavior to improve dairy cow health and welfare. More research is required to further study dairy cow behavior so as to better apply it in practical management and meet the needs of production.

  1. Applying the WEAP Model to Water Resource

    DEFF Research Database (Denmark)

    Gao, Jingjing; Christensen, Per; Li, Wei

    Water resources assessment is a tool to provide decision makers with an appropriate basis to make informed judgments regarding the objectives and targets to be addressed during the Strategic Environmental Assessment (SEA) process. The study shows how water resources assessment can be applied in SEA...... in assessing the effects on water resources using a case study on a Coal Industry Development Plan in an arid region in North Western China. In the case the WEAP model (Water Evaluation And Planning System) were used to simulate various scenarios using a diversity of technological instruments like irrigation...... efficiency, treatment and reuse of water. The WEAP model was applied to the Ordos catchment where it was used for the first time in China. The changes in water resource utilization in Ordos basin were assessed with the model. It was found that the WEAP model is a useful tool for water resource assessment...

  2. Thompson's Method applied to Quantum Electrodynamics (QED)

    CERN Document Server

    Nassif, C; Nassif, Claudio

    2000-01-01

    In this work we apply Thompson's method (of the dimensions) to study the quantum electrodynamics (QED). This method can be considered as a simple and alternative way to the renormalisation group (R.G) approach and when applied to QED lagrangian is able to obtain the running coupling constant behavior $\\alpha (\\mu)$, namely the dependence of $\\alpha$ on the energy scale. We also obtain the dependence of the mass on the energy scale. The calculations are evaluated just at $d_c=4$, where $d_c$ is the upper critical dimension of the problem, so that we obtain logarithmic behavior both for the coupling $\\alpha$ and the mass $m$ on the energy scale $\\mu$.

  3. Applied Anti-neutrino Physics 2013

    CERN Document Server

    2013-01-01

    This year, the 9th annual Applied Antineutrino Physics Workshop will be hosted by Sejong University, at the COEX conference center in Seoul South Korea. The workshop will be held on November 1(Friday) - 2(Saturday), 2013. Conveniently for many travelers, it takes place directly after and at the same venue as the 2013 IEEE Nuclear Science Symposium (http://www.nss-mic.org/2013/NSSMain.asp) Applied Antineutrino Physics describes an ensemble of experimental and theoretical efforts which aim to use the antineutrino signal from nuclear reactors, and from the Earth itself, in order to address practical problems in nonproliferation and geology respectively. Since the 2004 inception of these workshops, groups worldwide have made considerable advances in defining and expanding the field, garnering interest from the International Atomic Energy Agency (IAEA), which administers the worlds most important nonproliferation regime, and from the geology/geophysics community. This meeting will focus on the current activi...

  4. Risk assessment of topically applied products

    DEFF Research Database (Denmark)

    Søborg, Tue; Basse, Line Hollesen; Halling-Sørensen, Bent

    2007-01-01

    The human risk of harmful substances in semisolid topical dosage forms applied topically to normal skin and broken skin, respectively, was assessed. Bisphenol A diglycidyl ether (BADGE) and three derivatives of BADGE previously quantified in aqueous cream and the UV filters 3-BC and 4-MBC were used...... as model compounds. Tolerable daily intake (TDI) values have been established for BADGE and derivatives. Endocrine disruption was chosen as endpoint for 3-BC and 4-MBC. Skin permeation of the model compounds was investigated in vitro using pig skin membranes. Tape stripping was applied to simulate broken...... parameters for estimating the risk. The immediate human risk of BADGE and derivatives in topical dosage forms was found to be low. However, local treatment of broken skin may lead to higher exposure of BADGE and derivatives compared to application to normal skin. 3-BC permeated skin at higher flux than 4-MBC...

  5. Hans Wolter - a pioneer of applied optics

    CERN Document Server

    Schrimpf, Andreas

    2016-01-01

    Applied optics was one of the major topics Hans Walter was engaged in during his scientific life. He contributed to the understanding of optical properties of thin films, which could be used to design coating layers to improve the properties of optical and other surfaces. He developed the theoretical description of the basic principles of phase-contrast, schlieren and interference optics applied to enhance low contrast details and to increase the resolution in studies of biological samples. And last, but not least, Hans Wolter proposed an optical system of two grazing--incidence mirrors for use in an X--ray imaging microscope. A microscope using such an optics never was put into practice, but the optical design turned out to be well suited for telescopes.

  6. NASA's Applied Sciences for Water Resources

    Science.gov (United States)

    Doorn, Bradley; Toll, David; Engman, Ted

    2011-01-01

    The Earth Systems Division within NASA has the primary responsibility for the Earth Science Applied Science Program and the objective to accelerate the use of NASA science results in applications to help solve problems important to society and the economy. The primary goal of the Earth Science Applied Science Program is to improve future and current operational systems by infusing them with scientific knowledge of the Earth system gained through space-based observation, assimilation of new observations, and development and deployment of enabling technologies, systems, and capabilities. This paper discusses one of the major problems facing water resources managers, that of having timely and accurate data to drive their decision support tools. It then describes how NASA?s science and space based satellites may be used to overcome this problem. Opportunities for the water resources community to participate in NASA?s Water Resources Applications Program are described.

  7. Optimal alarm system applied in coffee rust

    Directory of Open Access Journals (Sweden)

    Luciene Resende Gonçalves

    2014-02-01

    Full Text Available Alarm systems have very great utility in detecting and warning of catastrophes. This methodology was applied via TARSO model with Bayesian estimation, serving as a forecasting mechanism for coffee rust disease. The coffee culture is very susceptible to this disease causing several records of incidence in most cultivated crops. Researches involving this limiting factor for production are intense and frequent, indicating environmental factors as responsible for the epidemics spread, which does not occur if these factors are not favorable. The fitting type used by the a posteriori probability, allows the system to be updated each time point. The methodology was applied to the rust index series in the presence of the average temperature series. Thus, it is possible to verify the alarm resulted or in a high catastrophe detection in points at which the catastrophe has not occurred, or in the low detections if the point was already in the catastrophe state.

  8. [Montessori method applied to dementia - literature review].

    Science.gov (United States)

    Brandão, Daniela Filipa Soares; Martín, José Ignacio

    2012-06-01

    The Montessori method was initially applied to children, but now it has also been applied to people with dementia. The purpose of this study is to systematically review the research on the effectiveness of this method using Medical Literature Analysis and Retrieval System Online (Medline) with the keywords dementia and Montessori method. We selected lo studies, in which there were significant improvements in participation and constructive engagement, and reduction of negative affects and passive engagement. Nevertheless, systematic reviews about this non-pharmacological intervention in dementia rate this method as weak in terms of effectiveness. This apparent discrepancy can be explained because the Montessori method may have, in fact, a small influence on dimensions such as behavioral problems, or because there is no research about this method with high levels of control, such as the presence of several control groups or a double-blind study.

  9. Applying System Engineering to Pharmaceutical Safety

    Directory of Open Access Journals (Sweden)

    Nancy Leveson

    2012-01-01

    Full Text Available While engineering techniques are used in the development of medical devices and have been applied to individual healthcare processes, such as the use of checklists in surgery and ICUs, the application of system engineering techniques to larger healthcare systems is less common. System safety is the part of system engineering that uses modeling and analysis to identify hazards and to design the system to eliminate or control them. In this paper, we demonstrate how to apply a new, safety engineering static and dynamic modeling and analysis approach to healthcare systems. Pharmaceutical safety is used as the example in the paper, but the same approach is potentially applicable to other complex healthcare systems. System engineering techniques can be used in re-engineering the system as a whole to achieve the system goals, including both enhancing the safety of current drugs while, at the same time, encouraging the development of new drugs.

  10. 12th International Congress of Applied Mechanics

    CERN Document Server

    Vincenti, Walter

    1969-01-01

    This volume contains the Proceedings of the Twelfth International Congress of Applied Mechanics, held at Stanford University on August 26 to 31, 1968. The Congress was organized by the International Union of Theoretical and Applied Mechanics; members of the IUTAM Congress Committee and Bureau are listed under Congress Organization. The members of the Stanford Organizing Committee, which was responsible for the detailed organization of the Congress, are also given, as are the names of the sponsors and the industrial and educational organizations that contributed so generously to the financial support of the meeting. Those attending the Congress came from 32 countries and totaled 1337 persons, plus wives and children. A list of the registered participants is included in the volume. The technical sessions of the Congress comprised four General Lectures and 281 contributed papers, the latter being presented in groups of five simultaneous sessions. The final choice of the contributed papers was made on the basis o...

  11. APPLIED ORIGAMI. Origami of thick panels.

    Science.gov (United States)

    Chen, Yan; Peng, Rui; You, Zhong

    2015-07-24

    Origami patterns, including the rigid origami patterns in which flat inflexible sheets are joined by creases, are primarily created for zero-thickness sheets. In order to apply them to fold structures such as roofs, solar panels, and space mirrors, for which thickness cannot be disregarded, various methods have been suggested. However, they generally involve adding materials to or offsetting panels away from the idealized sheet without altering the kinematic model used to simulate folding. We develop a comprehensive kinematic synthesis for rigid origami of thick panels that differs from the existing kinematic model but is capable of reproducing motions identical to that of zero-thickness origami. The approach, proven to be effective for typical origami, can be readily applied to fold real engineering structures.

  12. Applied Mathematics, Modelling and Computational Science

    CERN Document Server

    Kotsireas, Ilias; Makarov, Roman; Melnik, Roderick; Shodiev, Hasan

    2015-01-01

    The Applied Mathematics, Modelling, and Computational Science (AMMCS) conference aims to promote interdisciplinary research and collaboration. The contributions in this volume cover the latest research in mathematical and computational sciences, modeling, and simulation as well as their applications in natural and social sciences, engineering and technology, industry, and finance. The 2013 conference, the second in a series of AMMCS meetings, was held August 26–30 and organized in cooperation with AIMS and SIAM, with support from the Fields Institute in Toronto, and Wilfrid Laurier University. There were many young scientists at AMMCS-2013, both as presenters and as organizers. This proceedings contains refereed papers contributed by the participants of the AMMCS-2013 after the conference. This volume is suitable for researchers and graduate students, mathematicians and engineers, industrialists, and anyone who would like to delve into the interdisciplinary research of applied and computational mathematics ...

  13. Global Conference on Applied Physics and Mathematics

    CERN Document Server

    2016-01-01

    The Global Conference on Applied Physics and Mathematics is organized by academics and researchers belonging to different scientific areas of the C3i/Polytechnic Institute of Portalegre (Portugal) and the University of Extremadura (Spain) with the technical support of ScienceKnow Conferences. The event has the objective of creating an international forum for academics, researchers and scientists from worldwide to discuss worldwide results and proposals regarding to the soundest issues related to Applied Physics and Mathematics. This event will include the participation of renowned keynote speakers, oral presentations, posters sessions and technical conferences related to the topics dealt with in the Scientific Program as well as an attractive social and cultural program. The papers will be published in the Proceedings e-books. The proceedings of the conference will be sent to possible indexing on Thomson Reuters (selective by Thomson Reuters, not all-inclusive) and Google Scholar. Those communications con...

  14. APPLYING THE PRINCIPLES OF ACCOUNTING IN

    Directory of Open Access Journals (Sweden)

    NAGY CRISTINA MIHAELA

    2015-05-01

    Full Text Available The application of accounting principles (accounting principle on accrual basis; principle of business continuity; method consistency principle; prudence principle; independence principle; the principle of separate valuation of assets and liabilities; intangibility principle; non-compensation principle; the principle of substance over form; the principle of threshold significance to companies that are in bankruptcy procedure has a number of particularities. Thus, some principles cannot be applied to bankruptcy procedures (accounting principle on accrual basis, principle of business continuity, independence principle, intangibility principle and the principle of substance over form, some are available only in certain situations (method consistency principle and the prudence principle and others do not apply to bankruptcy (the principle of separate valuation of assets and liabilities; noncompensation principle and the principle of threshold significance.

  15. Recombinant vaccines: experimental and applied aspects

    DEFF Research Database (Denmark)

    Lorenzen, Niels

    1999-01-01

    Development of vaccines for aquaculture fish represent an important applied functional aspect of fish immunology research. Particularly in the case of recombinant vaccines, where a single antigen is usually expected to induce immunity to a specific pathogen, knowledge of mechanisms involved in in......, these fields will open up a number of interesting research objectives of mutual benefit. Recent aspects of recombinant protein vaccines, live recombinant vaccines and DNA vaccines are discussed.......Development of vaccines for aquaculture fish represent an important applied functional aspect of fish immunology research. Particularly in the case of recombinant vaccines, where a single antigen is usually expected to induce immunity to a specific pathogen, knowledge of mechanisms involved...... in induction of a protective immune response may become vital. The few recombinant vaccines licensd so far, despite much research during the last decade, illustrate that this is not a straightforward matter. However, as vaccine technology as well as our knowledge of the fish immune system is steadily improved...

  16. Biplot models applied to cancer mortality rates.

    Science.gov (United States)

    Osmond, C

    1985-01-01

    "A graphical method developed by Gabriel to display the rows and columns of a matrix is applied to tables of age- and period-specific cancer mortality rates. It is particularly useful when the pattern of age-specific rates changes with time. Trends in age-specific rates and changes in the age distribution are identified as projections. Three examples [from England and Wales] are given."

  17. Integrative Systems Biology Applied to Toxicology

    DEFF Research Database (Denmark)

    Kongsbak, Kristine Grønning

    associated with combined exposure to multiple chemicals. Testing all possible combinations of the tens of thousands environmental chemicals is impractical. This PhD project was launched to apply existing computational systems biology methods to toxicological research. In this thesis, I present in three...... of a system thereby suggesting new ways of thinking specific toxicological endpoints. Furthermore, computational methods can serve as valuable input for the hypothesis generating phase of the preparations of a research project....

  18. [Applied problems of mathematical biology and bioinformatics].

    Science.gov (United States)

    Lakhno, V D

    2011-01-01

    Mathematical biology and bioinformatics represent a new and rapidly progressing line of investigations which emerged in the course of work on the project "Human genome". The main applied problems of these sciences are grug design, patient-specific medicine and nanobioelectronics. It is shown that progress in the technology of mass sequencing of the human genome has set the stage for starting the national program on patient-specific medicine.

  19. Educational software design: applying models of learning

    Directory of Open Access Journals (Sweden)

    Stephen Richards

    1996-12-01

    Full Text Available The model of learning adopted within this paper is the 'spreading ripples' (SR model proposed by Race (1994. This model was chosen for two important reasons. First, it makes use of accessible ideas and language, .and is therefore simple. Second, .Race suggests that the model can be used in the design, of educational and training programmes (and can thereby be applied to the design of computer-based learning materials.

  20. Correspondence Analysis applied to psychological research

    OpenAIRE

    Laura Doey; Jessica Kurta

    2011-01-01

    Correspondence analysis is an exploratory data technique used to analyze categorical data (Benzecri, 1992). It is used in many areas such as marketing and ecology. Correspondence analysis has been used less often in psychological research, although it can be suitably applied. This article discusses the benefits of using correspondence analysis in psychological research and provides a tutorial on how to perform correspondence analysis using the Statistical Package for the Social Sciences (SPSS).