WorldWideScience

Sample records for voltammetry research results

  1. New Cyclic Voltammetry Method for Examining Phase Transitions: Simulated Results

    OpenAIRE

    2006-01-01

    We propose a new experimental technique for cyclic voltammetry, based on the first-order reversal curve (FORC) method for analysis of systems undergoing hysteresis. The advantages of this electrochemical FORC (EC-FORC) technique are demonstrated by applying it to dynamical models of electrochemical adsorption. The method can not only differentiate between discontinuous and continuous phase transitions, but can also quite accurately recover equilibrium behavior from dynamic analysis of systems...

  2. Research Results Research Results

    Science.gov (United States)

    2009-04-01

    A Highly Efficient Route for Selective Phenol Hydrogenation to Cyclohexanone A Novel Mechanism Employed by KSHV to Maintain the Latent Infection was Revealed Breakthrough in the Synthesis of Interconnected NW/NT and NT/NW/NT Heterojunctions with Branched Topology GABA Transporter-1 Activity Modulates Hippocampal Theta Oscillation and Theta Burst Stimulation-Induced Long-Term Potentiation Meta-analysis of Vitamin D, Calcium and the Prevention of Breast Cancer New Findings on the Origin of TrpRS PKCd Regulates Cortical Radial Migration by Stabilizing the Cdk5 Activator P35 PKU Research Team Publishes Papers on Inhalation Exposure to Pollutant and Cancer Risk Progress of the Research on Arbitrarily Elliptical Invisibility Cloaks An Advance in Complete Oxidation of Formaldehyde at Low Temperatures

  3. Cyclic Voltammetry.

    Science.gov (United States)

    Evans, Dennis H.; And Others

    1983-01-01

    Cyclic voltammetry is a simple experiment that has become popular in chemical research because it can provide useful information about redox reactions in a form which is easily obtained and interpreted. Discusses principles of the method and illustrates its use in the study of four electrode reactions. (Author/JN)

  4. Cyclic Voltammetry.

    Science.gov (United States)

    Evans, Dennis H.; And Others

    1983-01-01

    Cyclic voltammetry is a simple experiment that has become popular in chemical research because it can provide useful information about redox reactions in a form which is easily obtained and interpreted. Discusses principles of the method and illustrates its use in the study of four electrode reactions. (Author/JN)

  5. Research Results

    Science.gov (United States)

    2012-12-01

    Achievements in Sino-German Interdisciplinary Major Research Project Published by Small A Conserved Proline Switch on the Ribosome Facilitates the Recruitment and Binding of trGTPases Air Pollution Contributes in Sunshine Dimming in China Role of Lymphatic Trafficking and Biodistribution Soft Fibrin Gels Promote Selection and Growth of Tumorigenic Cells Targeted Therapy: The New Lease on Life for Acute Promyelocytic Leukemia, and Beyond The Structural Basis for the Sensing and Binding of Cyclic di-GMP by STING Research on Atomic-Scale Investigation of Li Storage Mechanism in Spinel Li4Ti5O12 NSFC Funded Project Made Significant Progress in Intelligent Nanomaterial and Device Palaeobotany and the Evolution of the Monsoon in China Non Heme System Asymmetric Epoxidation Reaction Made Progress Rapid Advancement of Immunology Study in China Chinese Experts Successfully Produced Transgenic Animals from Haploid Embryonic Stem Cells

  6. Research Results

    Science.gov (United States)

    2012-01-01

    In situ Oxidation Study of Pt (110) and Its Interaction with CO Chinese Scientists Published a Paper on Prevention of Drug Craving and Relapse by Memory Retrieval-extinction Procedure in Science Series Papers Published in Energy Policy: Modeling Energy Use of China's Road Transport and Policy Evaluation Breakthrough in the Ambient Catalytic Destruction of Formaldehyde Novel Findings for High Altitude Adaptation from the Yak Genome Binary Colloidal Structures Assembled through Ising Interactions Reemergence of superconductivity at 48K in Compressed Iron Selenide Based Superconductors Nucleosomes Suppress Spontaneous Mutations Base-Specifically in Eukaryotes Single-Chain Fragmented Antibodies Guided SiRNA Delivery in Breast Cancer Does Yeast Suicide? China Scientists Developed Important Methodologies for Spatiotemporal Detecting and Manipulating of Cellular Activities Scorpions Inspire Chinese Scientists in Making Bionic Non-eroding Surfaces for Machinery Research on Phylogenetic Placement of Borthwickia and Description of a New Family of Angiosperms, Borthwickiaceae Plasmoid Ejection and Secondary Current Sheet Generation from Magnetic Reconnection in Laser-plasma Interaction Cotton Bollworm Adapts to Bt Cotton via Diverse Mutations A Histone Acetyltransferase Regulates Active DNA Demethylation in Arabidopsis

  7. New Cyclic Voltammetry Method for Examining Phase Transitions on Electrodes: Simulated Results

    Science.gov (United States)

    Abou Hamad, Ibrahim; Robb, Daniel; Rikvold, Per Arne

    2007-03-01

    We propose a new experimental technique for cyclic voltammetry, based on the first-order reversal curve (FORC) method for analysis of systems undergoing hysteresis. The advantages of this technique are demonstrated by applying it to dynamical models of electrochemical adsorption. The method can not only differentiate between discontinuous and continuous phase transitions, but can also quite accurately recover equilibrium behavior from dynamic analysis of systems with a continuous phase transition. The FORC diagram for a discontinuous phase transition is characterized by a negative (unstable) region separating two positive (stable) regions, while such a negative region does not exist for continuous phase transitions. Experimental data for Electrochemical FORC (EC-FORC) analysis could easily be obtained by simple reprogramming of a potentiostat designed for conventional cyclic-voltammetry experiments.I. Abou Hamad, D.T. Robb, P.A. Rikvold, J. Electroanal. Chem., in press.

  8. Pulse Voltammetry.

    Science.gov (United States)

    Osteryoung, Janet

    1983-01-01

    Discusses the nature of pulse voltammetry, indicating that its widespread use arises from good sensitivity and detection limits and from ease of application and low cost. Provides analytical and mechanistic applications of the procedure. (JN)

  9. Voltammetry Method Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoyt, N. [Argonne National Lab. (ANL), Argonne, IL (United States); Pereira, C. [Argonne National Lab. (ANL), Argonne, IL (United States); Willit, J. [Argonne National Lab. (ANL), Argonne, IL (United States); Williamson, M. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-07-29

    The purpose of the ANL MPACT Voltammetry project is to evaluate the suitability of previously developed cyclic voltammetry techniques to provide electroanalytical measurements of actinide concentrations in realistic used fuel processing scenarios. The molten salts in these scenarios are very challenging as they include high concentrations of multiple electrochemically active species, thereby creating a variety of complications. Some of the problems that arise therein include issues related to uncompensated resistance, cylindrical diffusion, and alloying of the electrodeposited metals. Improvements to the existing voltammetry technique to account for these issues have been implemented, resulting in good measurements of actinide concentrations across a wide range of adverse conditions.

  10. Determination of Platinum Metals in Carbonaceous Mineral Raw Materials by Stripping Voltammetry

    OpenAIRE

    Kolpakova, Nina Alexandrovna; Oskina, Yuliya Aleksandrovna; Dyachenko, Elena Nikolaevna; Pshenichkin, Anatoliy Yakovlevich

    2015-01-01

    The paper considers the possibility of determining platinum metals in mineral raw materials by stripping voltammetry on a graphite electrode modified by metals. Stripping voltammetry method is characterized by low determination limit, wide intervals of determined content and high sensitivity. As a result of the research the conditions for the determination of gold, platinum and palladium by stripping voltammetry have been selected. The comparison of the results of gold, palladium and platinum...

  11. NIH Research to Results

    Science.gov (United States)

    ... on. The National Institute of Neurological Disorders and Stroke (NINDS) is researching treatments that can be given in the first hours after a TBI to prevent or reverse much of the brain damage resulting from the injury. A recently completed NINDS– ...

  12. Affordable Cyclic Voltammetry

    Science.gov (United States)

    Stewart, Greg; Kuntzleman, Thomas S.; Amend, John R.; Collins, Michael J.

    2009-01-01

    Cyclic voltammetry is an important component of the undergraduate chemical curriculum. Unfortunately, undergraduate students rarely have the opportunity to conduct experiments in cyclic voltammetry owing to the high cost of potentiostats, which are required to control these experiments. By using MicroLab data acquisition interfaces in conjunction…

  13. Affordable Cyclic Voltammetry

    Science.gov (United States)

    Stewart, Greg; Kuntzleman, Thomas S.; Amend, John R.; Collins, Michael J.

    2009-01-01

    Cyclic voltammetry is an important component of the undergraduate chemical curriculum. Unfortunately, undergraduate students rarely have the opportunity to conduct experiments in cyclic voltammetry owing to the high cost of potentiostats, which are required to control these experiments. By using MicroLab data acquisition interfaces in conjunction…

  14. Recent Advances in Voltammetry

    Science.gov (United States)

    Batchelor-McAuley, Christopher; Kätelhön, Enno; Barnes, Edward O; Compton, Richard G; Laborda, Eduardo; Molina, Angela

    2015-01-01

    Recent progress in the theory and practice of voltammetry is surveyed and evaluated. The transformation over the last decade of the level of modelling and simulation of experiments has realised major advances such that electrochemical techniques can be fully developed and applied to real chemical problems of distinct complexity. This review focuses on the topic areas of: multistep electrochemical processes, voltammetry in ionic liquids, the development and interpretation of theories of electron transfer (Butler–Volmer and Marcus–Hush), advances in voltammetric pulse techniques, stochastic random walk models of diffusion, the influence of migration under conditions of low support, voltammetry at rough and porous electrodes, and nanoparticle electrochemistry. The review of the latter field encompasses both the study of nanoparticle-modified electrodes, including stripping voltammetry and the new technique of ‘nano-impacts’. PMID:26246984

  15. Recent Advances in Voltammetry.

    Science.gov (United States)

    Batchelor-McAuley, Christopher; Kätelhön, Enno; Barnes, Edward O; Compton, Richard G; Laborda, Eduardo; Molina, Angela

    2015-06-01

    Recent progress in the theory and practice of voltammetry is surveyed and evaluated. The transformation over the last decade of the level of modelling and simulation of experiments has realised major advances such that electrochemical techniques can be fully developed and applied to real chemical problems of distinct complexity. This review focuses on the topic areas of: multistep electrochemical processes, voltammetry in ionic liquids, the development and interpretation of theories of electron transfer (Butler-Volmer and Marcus-Hush), advances in voltammetric pulse techniques, stochastic random walk models of diffusion, the influence of migration under conditions of low support, voltammetry at rough and porous electrodes, and nanoparticle electrochemistry. The review of the latter field encompasses both the study of nanoparticle-modified electrodes, including stripping voltammetry and the new technique of 'nano-impacts'.

  16. Sharing Research Results

    Science.gov (United States)

    Ashbrook, Peggy

    2011-01-01

    There are many ways to share a collection of data and students' thinking about that data. Explaining the results of science inquiry is important--working scientists and amateurs both contribute information to the body of scientific knowledge. Students can collect data about an activity that is already happening in a classroom (e.g., the qualities…

  17. Cyclic Voltammetry Experiment.

    Science.gov (United States)

    Van Benschoten, James J.; And Others

    1983-01-01

    Describes a three-part experiment designed to introduce cyclic voltammetry to graduate/undergraduate students. Part 1 demonstrates formal reduction potential, redox electron transfer, diffusion coefficient, and electrochemical reversibility. Part 2 investigates electrochemical behavior of acetaminophen. Part 3 examines such experimental variables…

  18. Cyclic Voltammetry Experiment.

    Science.gov (United States)

    Van Benschoten, James J.; And Others

    1983-01-01

    Describes a three-part experiment designed to introduce cyclic voltammetry to graduate/undergraduate students. Part 1 demonstrates formal reduction potential, redox electron transfer, diffusion coefficient, and electrochemical reversibility. Part 2 investigates electrochemical behavior of acetaminophen. Part 3 examines such experimental variables…

  19. Voltammetry of Medical Biomaterials

    OpenAIRE

    Gulaboski, Rubin; Markovski, Velo

    2015-01-01

    The use of biomaterials in the medicine, dentistry and pharmacy represents probably a major breakthrough in tackling many diseases or disabilities in the last 50 years. We refer to varios techniques that are used for the characterization of the structure and the composition of the biomaterials. Voltammetry is an electrochemical technique that helps mainly in understanding the redox properties of various biomaterials containing some suitable redox centers in their structure. We give in this le...

  20. Cyclic voltammetry of supported BLMs

    Science.gov (United States)

    Murgasova, Renata; Sabo, Jan; Ottova, Angelica L.; Tien, H. T.

    1996-06-01

    The transfer of an electron across a bilayer lipid membrane (BLM) is one of the BLMs most exciting processes. A number of well known electron mediators have been investigated using the method of cyclic voltammetry on a Teflon coated platinum wire, the tip of which has been modified by a self-assembled bilayer lipid membrane (s-BLM). The electrical capacitance of the s-BLM system was measured as a function of frequency. The results are discussed in terms of electron transfer and redox reactions.

  1. Cell Phones: Current Research Results

    Science.gov (United States)

    ... Potential Biological or Adverse Health Effects of Wireless Communication Devices World Health Organization: Electromagnetic Fields and Public Health: Mobile Phones International Agency for Research on Cancer Press ...

  2. Evaluation of homogeneous electrocatalysts by cyclic voltammetry.

    Science.gov (United States)

    Rountree, Eric S; McCarthy, Brian D; Eisenhart, Thomas T; Dempsey, Jillian L

    2014-10-06

    The pursuit of solar fuels has motivated extensive research on molecular electrocatalysts capable of evolving hydrogen from protic solutions, reducing CO2, and oxidizing water. Determining accurate figures of merit for these catalysts requires the careful and appropriate application of electroanalytical techniques. This Viewpoint first briefly presents the fundamentals of cyclic voltammetry and highlights practical experimental considerations before focusing on the application of cyclic voltammetry for the characterization of electrocatalysts. Key metrics for comparing catalysts, including the overpotential (η), potential for catalysis (E(cat)), observed rate constant (k(obs)), and potential-dependent turnover frequency, are discussed. The cyclic voltammetric responses for a general electrocatalytic one-electron reduction of a substrate are presented along with methods to extract figures of merit from these data. The extension of this analysis to more complex electrocatalytic schemes, such as those responsible for H2 evolution and CO2 reduction, is then discussed.

  3. Aptasensors Based on Stripping Voltammetry

    Directory of Open Access Journals (Sweden)

    Wenjing Qi

    2016-07-01

    Full Text Available Aptasensors based on stripping voltammetry exhibit several advantages, such as high sensitivity and multi-target detection from stripping voltammetric technology, and high selectivity from the specific binding of apamers with targets. This review comprehensively discusses the recent accomplishments in signal amplification strategies based on nanomaterials, such as metal nanoparticles, semiconductor nanoparticles, and nanocomposite materials, which are detected by stripping voltammetry after suitable dissolution. Focus will be put in discussing multiple amplification strategies that are widely applied in aptasensors for small biomolecules, proteins, disease markers, and cancer cells.

  4. Applications of convolution voltammetry in electroanalytical chemistry.

    Science.gov (United States)

    Bentley, Cameron L; Bond, Alan M; Hollenkamp, Anthony F; Mahon, Peter J; Zhang, Jie

    2014-02-18

    The robustness of convolution voltammetry for determining accurate values of the diffusivity (D), bulk concentration (C(b)), and stoichiometric number of electrons (n) has been demonstrated by applying the technique to a series of electrode reactions in molecular solvents and room temperature ionic liquids (RTILs). In acetonitrile, the relatively minor contribution of nonfaradaic current facilitates analysis with macrodisk electrodes, thus moderate scan rates can be used without the need to perform background subtraction to quantify the diffusivity of iodide [D = 1.75 (±0.02) × 10(-5) cm(2) s(-1)] in this solvent. In the RTIL 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, background subtraction is necessary at a macrodisk electrode but can be avoided at a microdisk electrode, thereby simplifying the analytical procedure and allowing the diffusivity of iodide [D = 2.70 (±0.03) × 10(-7) cm(2) s(-1)] to be quantified. Use of a convolutive procedure which simultaneously allows D and nC(b) values to be determined is also demonstrated. Three conditions under which a technique of this kind may be applied are explored and are related to electroactive species which display slow dissolution kinetics, undergo a single multielectron transfer step, or contain multiple noninteracting redox centers using ferrocene in an RTIL, 1,4-dinitro-2,3,5,6-tetramethylbenzene, and an alkynylruthenium trimer, respectively, as examples. The results highlight the advantages of convolution voltammetry over steady-state techniques such as rotating disk electrode voltammetry and microdisk electrode voltammetry, as it is not restricted by the mode of diffusion (planar or radial), hence removing limitations on solvent viscosity, electrode geometry, and voltammetric scan rate.

  5. Voltammetry of conducting polymers

    OpenAIRE

    Gulaboski, Rubin

    2014-01-01

    The search for new materials for enhancing electrical conductivity of various materials is one of the most active research areas today. Conducting polymers represent a unique class of organic materials that have been used in many applications such as bioelectronics, sensors, corrosion protection, electrocatalysis, and energy storage devices. Application of the conductive polymers in electrochemistry is almost inevitable in order to get better features of the voltammetric systems ...

  6. Marine ecological reserves research program: research results 1996-2001

    National Research Council Canada - National Science Library

    2002-01-01

    This is a collection of results of research done through the Marine Ecological Reserves Research Program, a competitive, peer-review research program focusing on the four new marine ecological reserves...

  7. Human Tissue Research: Who Owns the Results.

    Science.gov (United States)

    Wagner, Allen B.

    1987-01-01

    Ownership issues in the results of research generally and of human tissue research specifically are explored. While acknowledging some uncertainty in the law, it is found that human tissue may be lawfully accessed for research and that use of human tissue does not modify the general allocation of interests. (MSE)

  8. Innovation Impact: Breakthrough Research Results (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-07-01

    The Innovation Impact brochure captures key breakthrough results across NREL's primary areas of renewable energy and energy efficiency research: solar, wind, bioenergy, transportation, buildings, analysis, and manufacturing technologies.

  9. Focus on Communication: NIH Research to Results

    Science.gov (United States)

    ... Current Issue Past Issues Special Section: Focus on Communication NIH Research to Results Past Issues / Fall 2008 ... grew new hair cells. Read More "Focus on Communication" Articles Living with Hearing Loss / Anatomy of the ...

  10. Innovation Impact: Breakthrough Research Results (Brochure)

    Energy Technology Data Exchange (ETDEWEB)

    2013-07-01

    The Innovation Impact brochure captures key breakthrough results across NREL's primary areas of renewable energy and energy efficiency research: solar, wind, bioenergy, transportation, buildings, analysis, and manufacturing technologies.

  11. Skin Cancer: NIH Research to Results

    Science.gov (United States)

    ... of this page please turn Javascript on. Feature: Skin Cancer NIH Research to Results Past Issues / Summer 2013 ... making a person immune to his or her skin cancer cells. Another method is to train a person's ...

  12. Confidence crisis of results in biomechanics research.

    Science.gov (United States)

    Knudson, Duane

    2017-11-01

    Many biomechanics studies have small sample sizes and incorrect statistical analyses, so reporting of inaccurate inferences and inflated magnitude of effects are common in the field. This review examines these issues in biomechanics research and summarises potential solutions from research in other fields to increase the confidence in the experimental effects reported in biomechanics. Authors, reviewers and editors of biomechanics research reports are encouraged to improve sample sizes and the resulting statistical power, improve reporting transparency, improve the rigour of statistical analyses used, and increase the acceptance of replication studies to improve the validity of inferences from data in biomechanics research. The application of sports biomechanics research results would also improve if a larger percentage of unbiased effects and their uncertainty were reported in the literature.

  13. How to present and publish research results

    Directory of Open Access Journals (Sweden)

    Dekanski Aleksandar

    2014-01-01

    Full Text Available The end of each research is to present its results to the public, especially to those who are engaged in similar research. This is particularly true for scientific research. Scientific paper is written report that contains a presentation of the results of the original scientific research. Its format is defined by centuries-old tradition of writing, the editorial practices of the publishers, scientific ethics, accepted standards and requirements of modern printing and publishing. Unfortunately, the experience of the publishers and editors of scientific books and journals show that a large number of submitted contributions are not meeting the minimum requirements to be even considered. This article indicates the most important principles that one should have in mind during creation of full text paper or presentation of scientific results.

  14. Interpretation and display of research results

    Directory of Open Access Journals (Sweden)

    Dilip Kumar Kulkarni

    2016-01-01

    Full Text Available It important to properly collect, code, clean and edit the data before interpreting and displaying the research results. Computers play a major role in different phases of research starting from conceptual, design and planning, data collection, data analysis and research publication phases. The main objective of data display is to summarize the characteristics of a data and to make the data more comprehensible and meaningful. Usually data is presented depending upon the type of data in different tables and graphs. This will enable not only to understand the data behaviour, but also useful in choosing the different statistical tests to be applied.

  15. HARVESTING EMSP RESEARCH RESULTS FOR WASTE CLEANUP

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, Donna Post; Nielson, R. Bruce; Phillips, Ann Marie; Lebow, Scott

    2003-02-27

    The extent of environmental contamination created by the nuclear weapons legacy combined with expensive, ineffective waste cleanup strategies at many U.S. Department of Energy (DOE) sites prompted Congress to pass the FY96 Energy and Water Development Appropriations Act, which directed the DOE to: ''provide sufficient attention and resources to longer-term basic science research, which needs to be done to ultimately reduce cleanup costs'', ''develop a program that takes advantage of laboratory and university expertise, and'' ''seek new and innovative cleanup methods to replace current conventional approaches which are often costly and ineffective.'' In response, the DOE initiated the Environmental Management Science Program (EMSP)-a targeted, long-term research program intended to produce solutions to DOE's most pressing environmental problems. EMSP funds basic research to lower cleanup cost and reduce risk to workers, the public, and the environment; direct the nation's scientific infrastructure towards cleanup of contaminated waste sites; and bridge the gap between fundamental research and technology development activities. EMSP research projects are competitively awarded based on the project's scientific, merit coupled with relevance to addressing DOE site needs. This paper describes selected EMSP research projects with long, mid, and short-term deployment potential and discusses the impacts, focus, and results of the research. Results of EMSP research are intended to accelerate cleanup schedules, reduce cost or risk for current baselines, provide alternatives for contingency planning, or provide solutions to problems where no solutions exist.

  16. "Action": Publishing Research Results in Film

    Directory of Open Access Journals (Sweden)

    Susan Thieme

    2012-01-01

    Full Text Available Researchers commonly disseminate their research findings in academic papers or books that have a selected and limited target audience. A potential method for disseminating the information other than the traditional academic is through film, but this means tailoring the material to this medium and in many cases collaborating with people who have the necessary skills. The aim of this article is to reflect on the experience of making a film from the researcher's perspective. I will in particular shed light on how the filmmaking team worked together and provide examples of the preceding research, as well as the shooting and editing of the film material. The long period of research leading up to the film was a major factor in its success. In addition, all of the people involved have to be willing to share their experiences, recognize each other's expertise and be able to compromise. The film was much more than just an extension of the ongoing multi-site qualitative research. The shooting not only provided new insights into people's lives but also forced me to think much harder about my research and "the fieldwork." The additional costs and efforts related to the film can be justified by a transdisciplinary understanding of research that requires the results to be disseminated beyond academic circles, attract attention from policymakers and activists, and also allow the subjects of the research (who generally do not read English academic articles to become an active audience. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1201316

  17. Expert Meeting Report. Foundations Research Results

    Energy Technology Data Exchange (ETDEWEB)

    Ojczyk, C. [Univ. of Minnesota, St. Paul, MN (United States); Huelman, P. [Univ. of Minnesota, St. Paul, MN (United States); Carmody, J. [Univ. of Minnesota, St. Paul, MN (United States)

    2013-05-01

    The NorthernSTAR Building America Partnership held an expert meeting on Foundations–Research Results on November 15, 2011, in Minneapolis, MN. Audience participation was actively encouraged during each presentation to uncover needs and promote dialog among researchers and industry professionals. Key results were: greater understanding of the role of moisture transport through foundation and insulation materials and its potential impact on building durability; greater understanding of the role of foundation type in the process of selecting an insulation system for energy performance and building durability; need for research to quantify the risks associated with insulation processes to better enable users to weigh costs and benefits against the existing conditions of a home; need for improved performance modeling capabilities that address variations in foundation types and soil conditions.

  18. 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.

  19. Determination of chitosan by cathodic stripping voltammetry.

    Science.gov (United States)

    Lu, Guanghan; Wang, Lirong; Wang, Ruixia; Zeng, Yan; Huang, Xi

    2006-04-01

    A sensitive method for the determination of chitosan (CTS) by cathodic stripping voltammetry is presented. The method exploits a pair of oxidation-reduction peaks of CTS at -0.62 V (vs. SCE) and -0.54 V (vs. SCE), and an enhancement of the peak current of CTS observed in a 0.05 mol l(-1) potassium hydrogenphthalate buffer solution (pH 2.5). The peak current is linear with the concentration of CTS from 5.0 x 10(-7) to 1.5 x 10(-5) g ml(-1), and the detection limit is 1.0 x 10(-7) g ml(-1). We studied the characteristics and the mechanism of the electrode reaction, which proved that this process was diffusion controlled. This method was applied to determine the content of CTS in real samples with satisfactory results.

  20. Results of LWR snubber aging research

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D P [Lake Engineering Co., Greenville, RI (United States); Werry, E V; Blahnik, D E [Pacific Northwest Lab., Richland, WA (United States)

    1992-05-01

    This report describes the aging research results and recommendations for snubbers used in commercial nuclear power plants. Snubbers are safety-related devices used to restrain undesirable dynamic loads at various piping and equipment locations in nuclear power plants (NPPs). Each snubber must accommodate a plant's normal thermal movements and must be capable of restraining the maximum off-normal dynamic loads, such as a seismic event or a transient, postulated for its specific location. The effects of snubber aging and the factors that contribute to the degradation of their safety performance need to be better understood. Thus, Phase II of Nuclear Plant Aging Research was conducted to enhance the understanding of snubber aging and its consequences. Pacific Northwest Laboratory staff and their subcontractors, Lake Engineering and Wyle Laboratories, visited eight sites (encompassing thirteen plants) to conduct interviews with NPP staff and to collect data on snubber aging, testing, and maintenance. The Phase II research methodology, evaluation, results, conclusions, and recommendations are described in the report. Effective methods for service-life monitoring of snubbers are included in the recommendations.

  1. Space Research Results Purify Semiconductor Materials

    Science.gov (United States)

    2010-01-01

    While President Obama's news that NASA would encourage private companies to develop vehicles to take NASA into space may have come as a surprise to some, NASA has always encouraged private companies to invest in space. More than two decades ago, NASA established Commercial Space Centers across the United States to encourage industry to use space as a place to conduct research and to apply NASA technology to Earth applications. Although the centers are no longer funded by NASA, the advances enabled by that previous funding are still impacting us all today. For example, the Space Vacuum Epitaxy Center (SVEC) at the University of Houston, one of the 17 Commercial Space Centers, had a mission to create advanced thin film semiconductor materials and devices through the use of vacuum growth technologies both on Earth and in space. Making thin film materials in a vacuum (low-pressure environment) is advantageous over making them in normal atmospheric pressures, because contamination floating in the air is lessened in a vacuum. To grow semiconductor crystals, researchers at SVEC utilized epitaxy the process of depositing a thin layer of material on top of another thin layer of material. On Earth, this process took place in a vacuum chamber in a clean room lab. For space, the researchers developed something called the Wake Shield Facility (WSF), a 12-foot-diameter disk-shaped platform designed to grow thin film materials using the low-pressure environment in the wake of the space shuttle. Behind an orbiting space shuttle, the vacuum levels are thousands of times better than in the best vacuum chambers on Earth. Throughout the 1990s, the WSF flew on three space shuttle missions as a series of proof-of-concept missions. These experiments are a lasting testament to the success of the shuttle program and resulted in the development of the first thin film materials made in the vacuum of space, helping to pave the way for better thin film development on Earth.

  2. Scintilla European project, the successful research results

    Energy Technology Data Exchange (ETDEWEB)

    Sannie, G.; Kondrasov, V.; Corre, G.; Boudergui, K.; Perot, B.; Carasco, C.; Montemont, G. [Commissariat a l' energie atomique et aux energies alternatives, Saclay, Cadarache, Grenoble (France); Peerani, P.; Carrapico, C.; Tomanin, A.; Rosas, F.; Caviglia, M.; Eklund, G.; Tagziria, H. [European Commission, Joint Research Centre, ITU, Nuclear Security Unit, Ispra (Italy); Friedrich, H.; Chmel, S. [Fraunhofer-Institut fuer Naturwissenschaftlich - Technische Trendanalysen - INT, Euskirchen (Germany); De Vita, R.; Manchini, E.; Pavan, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova, Genova (Italy); Grattarola, M.; Botta, E. [Ansaldo Nucleare S.P.A, Genova (Italy); Kovacs, A.; Lakosi, L. [Hungarian Academy of Sciences, Centre for Energy Research, Budapest (Hungary); Baumhauer, C.; Deheuninck, T.; Haddad, E. [ARTTIC, Paris (France); Petrossian, G.; Ferragut, A. [SAPHYMO, Massy (France); Dermody, G.; Crossingham, G. [Symetrica Security Ltd, Southampton (United Kingdom)

    2015-07-01

    The Scintilla FP7 project is ended in December 2014, the fruitful results of 3 years development and tests will be presented. SCINTILLA offers the capacity to finding a reliable alternative to Helium-3 based detection systems since the gas which is predominantly used in nuclear safeguards and security applications has now become very expensive, rare and nearly unavailable. SCINTILLA benchmarks results are based on international standards. Radiation Portal tests were carried out at the Joint Research Centre (JRC) in Ispra (Italy). The scintilla project addresses few mains issues. The first is to develop neutron detectors for Radiation Portal Monitor (RPM) and the second is the need of new wearable integrated solutions for Spectrometric Personal Radiation Monitor (SPRM). The partners which provide technical systems of the scintilla project are INFN-ANSALDO, CEA, SYMETRICA and SAPHYMO. For RPM, the objective is to find reliable alternatives to Helium-3 historical neutron detector and provide technical solutions which cope with tests for reliable mobile and cost effective. For Spectrometric Personal Radiation Monitor (SPRM), SCINTILLA is innovating in technology areas that offer complementary capabilities for detecting and identifying gamma, Two CZT (Cadmium Zinc Telluride) addressing contexts of used by first responder technologies, one is a wearable detector and the second is a gamma camera complemented by advanced image processing technologies. (authors)

  3. Anodic stripping voltammetry enhancement by redox magnetohydrodynamics.

    Science.gov (United States)

    Clark, Emily A; Fritsch, Ingrid

    2004-04-15

    The effect of an external magnetic field on linear scan anodic stripping voltammetry (ASV) in solutions of 10(-6)-10(-7) M concentrations of lead, cadmium, and copper at mercury films on glassy carbon electrodes has been investigated. A high concentration of Hg(2+) was added to the analyte solution to induce a large cathodic current during the deposition step. Therefore, a large Lorentz force from the net flux of charge through the magnetic field resulted in convection due to magnetohydrodynamics. The faster delivery of analytes to the mercury film electrode during deposition caused an increase in the anodic stripping peaks. The effect of varying Hg(2+) concentrations (0-60 mM) and magnetic field strengths (0-1.77 T) on the enhancement of the stripping peaks was investigated. Enhancements as large as 129% for peak currents and 167% for peak areas were observed. An enhancement of approximately 100% was observed when 60 mM Fe(3+) replaced high concentrations of Hg(2+). This method of convection exhibits promise for small-volume ASV analysis with possible improved limits of detection and decreased preconcentration times.

  4. Use of a modified, high-sensitivity, anodic stripping voltammetry method for determination of zinc speciation in the North Atlantic Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Jakuba, Rachel Wisniewski [Massachusetts Institute of Technology, Woods Hole Oceanographic Institution Joint Program in Chemical Oceanography, 266 Woods Hole Road, Woods Hole, MA 02543 (United States)], E-mail: jakuba.rachel@epa.gov; Moffett, James W. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543 (United States)], E-mail: jmoffett@usc.edu; Saito, Mak A. [Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543 (United States)

    2008-05-05

    Zinc speciation is considered to be an important determinant of the biological availability of zinc. Yet in oceanic surface waters, characterization of zinc speciation is difficult due to the low concentrations of this essential micronutrient. In this study, an anodic stripping voltammetry method previously developed for the total determination of cadmium and lead was successfully adapted to the measurement of zinc speciation. The method differs from previous zinc speciation anodic stripping voltammetry methods in that a fresh mercury film is plated with each sample aliquot. The fresh film anodic stripping voltammetry method was compared to competitive ligand exchange cathodic stripping voltammetry in a profile from the North Atlantic Ocean. Results using the fresh film anodic stripping voltammetry method were similar to those determined using the cathodic stripping voltammetry method, though ligand concentrations determined by fresh film anodic stripping voltammetry were generally slightly higher than those determined by cathodic stripping voltammetry. There did not seem to be a systematic difference between methods for the estimates of conditional stability constants. The ligand concentration in the North Atlantic profile ranged from 0.9 to 1.5 nmol L{sup -1} as determined by fresh film anodic stripping voltammetry and 0.6 to 1.3 nmol L{sup -1} as determined by cathodic stripping voltammetry. The conditional stability constants determined by fresh film anodic stripping voltammetry were 10{sup 9.8}-10{sup 10.5} and by cathodic stripping voltammetry were 10{sup 9.8}-10{sup 11.3}.

  5. Use of a modified, high-sensitivity, anodic stripping voltammetry method for determination of zinc speciation in the North Atlantic Ocean.

    Science.gov (United States)

    Jakuba, Rachel Wisniewski; Moffett, James W; Saito, Mak A

    2008-05-05

    Zinc speciation is considered to be an important determinant of the biological availability of zinc. Yet in oceanic surface waters, characterization of zinc speciation is difficult due to the low concentrations of this essential micronutrient. In this study, an anodic stripping voltammetry method previously developed for the total determination of cadmium and lead was successfully adapted to the measurement of zinc speciation. The method differs from previous zinc speciation anodic stripping voltammetry methods in that a fresh mercury film is plated with each sample aliquot. The fresh film anodic stripping voltammetry method was compared to competitive ligand exchange cathodic stripping voltammetry in a profile from the North Atlantic Ocean. Results using the fresh film anodic stripping voltammetry method were similar to those determined using the cathodic stripping voltammetry method, though ligand concentrations determined by fresh film anodic stripping voltammetry were generally slightly higher than those determined by cathodic stripping voltammetry. There did not seem to be a systematic difference between methods for the estimates of conditional stability constants. The ligand concentration in the North Atlantic profile ranged from 0.9 to 1.5 nmol L(-1) as determined by fresh film anodic stripping voltammetry and 0.6 to 1.3 nmol L(-1) as determined by cathodic stripping voltammetry. The conditional stability constants determined by fresh film anodic stripping voltammetry were 10(9.8)-10(10.5) and by cathodic stripping voltammetry were 10(9.8)-10(11.3).

  6. Manganese Detection with a Metal Catalyst Free Carbon Nanotube Electrode: Anodic versus Cathodic Stripping Voltammetry

    Science.gov (United States)

    Yue, Wei; Bange, Adam; Riehl, Bill L.; Riehl, Bonnie D.; Johnson, Jay M.; Papautsky, Ian; Heineman, William R.

    2013-01-01

    Anodic stripping voltammetry (ASV) and cathodic stripping voltammetry (CSV) were used to determine Mn concentration using metal catalyst free carbon nanotube (MCFCNT) electrodes and square wave stripping voltammetry (SWSV). The MCFCNTs are synthesized using a Carbo Thermal Carbide Conversion method which results in a material that does not contain residual transition metals. Detection limits of 120 nM and 93 nM were achieved for ASV and CSV, respectively, with a deposition time of 60 s. CSV was found to be better than ASV in Mn detection in many aspects, such as limit of detection and sensitivity. The CSV method was used in pond water matrix addition measurements. PMID:24235806

  7. Manganese Detection with a Metal Catalyst Free Carbon Nanotube Electrode: Anodic versus Cathodic Stripping Voltammetry.

    Science.gov (United States)

    Yue, Wei; Bange, Adam; Riehl, Bill L; Riehl, Bonnie D; Johnson, Jay M; Papautsky, Ian; Heineman, William R

    2012-10-01

    Anodic stripping voltammetry (ASV) and cathodic stripping voltammetry (CSV) were used to determine Mn concentration using metal catalyst free carbon nanotube (MCFCNT) electrodes and square wave stripping voltammetry (SWSV). The MCFCNTs are synthesized using a Carbo Thermal Carbide Conversion method which results in a material that does not contain residual transition metals. Detection limits of 120 nM and 93 nM were achieved for ASV and CSV, respectively, with a deposition time of 60 s. CSV was found to be better than ASV in Mn detection in many aspects, such as limit of detection and sensitivity. The CSV method was used in pond water matrix addition measurements.

  8. Determination of ziram in vegetable samples by square wave voltammetry

    Institute of Scientific and Technical Information of China (English)

    Ping Qiu; Yong Nian Ni

    2008-01-01

    The electrochemical behaviour and electrode reaction mechanism of ziram (zinc-dimethyl dithiocarbamate) on a hanging mercury drop electrode were investigated in Britton-Robinson (B-R) buffer by using cyclic and square wave voltammetry (SWV).Based on these studies a voltammetric method for determination of ziram was developed and applied to determine the ziram in synthetic and spiked vegetable samples,satisfactory results were obtained in both eases.

  9. Ultrafast cyclic voltammetry with asymmetrical potential scan

    Institute of Scientific and Technical Information of China (English)

    Zhi Yong Guo; Xiang Qin Lin

    2008-01-01

    Based on the perfect ohmic drop compensation by online electronic positive feedback, ultrafast cyclic voltammetry withasymmetrical potential scan is achieved for the first time, with the reduction of anthracene acting as the test system. Compared withthe traditional cyclic voltammetry utilizing symmetrical triangular waveform as the excitation one, the new method allows a simplerapproach to mechanistic analysis of ultrafast chemical reactions coupled with a charge transfer. And perhaps more important, it alsoprovides a way to eliminate the interference of the adsorbed product in dynamic monitoring.

  10. Linear Sweep Voltammetry of Adsorbed Neutral Red.

    Science.gov (United States)

    1982-05-01

    E. Creager, G. T. Marks, D. A. Aikens and H. H. Richtol Prepared for Publication in Journal of Electroanalytical Chemistry Rensselaer Polytechnic... Electroanalytical Chemistry It. KEY WORDS (Continue oun reverse side It necessary mid Ideneliy by block ntaibor) Neutral Red, cyclic voltammetry, adsorbed dye 20

  11. Steady state oxygen reduction and cyclic voltammetry

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Karlberg, Gustav; Jaramillo, Thomas;

    2008-01-01

    The catalytic activity of Pt and Pt3Ni for the oxygen reduction reaction is investigated by applying a Sabatier model based on density functional calculations. We investigate the role of adsorbed OH on the activity, by comparing cyclic voltammetry obtained from theory with previously published...

  12. Voltammetry at porous electrodes: A theoretical study

    CERN Document Server

    Barnes, Edward O; Li, Peilin; Compton, Richard G

    2014-01-01

    Theory is presented to simulate both chronoamperometry and cyclic voltammetry at porous electrodes fabricated by means of electro-deposition around spherical templates. A theoretical method to extract heterogeneous rate constants for quasireversible and irreversible systems is proposed by the approximation of decoupling of the diffusion within the porous electrode and of bulk diffusion to the electrode surface.

  13. Anodic Stripping Voltammetry: An Instrumental Analysis Experiment.

    Science.gov (United States)

    Wang, Joseph

    1983-01-01

    Describes an experiment designed to acquaint students with the theory and applications of anodic stripping voltammetry (ASV) as well as such ASV problems as contamination associated with trace analysis. The experimental procedure, instrumentation, and materials discussed are designed to minimize cost and keep procedures as simple as possible. (JM)

  14. A Brief Syntactic Research on Resultative Construction

    Institute of Scientific and Technical Information of China (English)

    邱林林

    2008-01-01

    <正>This article will deal with Resultative Construction syntactically.First of all,the Unaccusative Hypothesis will be introduced,and the ideas of different scholars(mainly Levin and Rappaport) towards the question--whether the resultative construction can serve as diagnostic test to tell unergative verbs and unaccusative verbs apart--will be presented.The second focus of the article is about the differences that tell resultative constructions apart from depicitive construction and secondary predication construction.

  15. Advanced Materials for Exploration Task Research Results

    Science.gov (United States)

    Cook, M. B. (Compiler); Murphy, K. L.; Schneider, T.

    2008-01-01

    The Advanced Materials for Exploration (AME) Activity in Marshall Space Flight Center s (MSFC s) Exploration Science and Technology Directorate coordinated activities from 2001 to 2006 to support in-space propulsion technologies for future missions. Working together, materials scientists and mission planners identified materials shortfalls that are limiting the performance of long-term missions. The goal of the AME project was to deliver improved materials in targeted areas to meet technology development milestones of NASA s exploration-dedicated activities. Materials research tasks were targeted in five areas: (1) Thermal management materials, (2) propulsion materials, (3) materials characterization, (4) vehicle health monitoring materials, and (5) structural materials. Selected tasks were scheduled for completion such that these new materials could be incorporated into customer development plans.

  16. Differential pulse voltammetry and additive differential pulse voltammetry with solvent polymeric membrane ion sensors.

    Science.gov (United States)

    Ortuño, J A; Serna, C; Molina, A; Gil, A

    2006-12-01

    The ion transfer across the water-solvent polymeric membrane interface is investigated by using a new device based on a modification of a commercial ion-selective electrode body that permits the accommodation of a platinum counter electrode inside the inner filling solution compartment and, therefore, use of a four-electrode potentiostat with ohmic drop compensation. This device is used here to apply two different double potential pulse techniques--differential pulse voltammetry and additive differential pulse voltammetry--which are more advantageous than other voltammetric techniques, such as normal pulse voltammetry or cyclic voltammetry, for the determination of the characteristic electrochemical parameters of the system. This is due to the concurrence of two factors in these double potential pulse techniques, the peak-shaped response together with a considerable reduction of undesirable current contributions.

  17. Cyclic Voltammetry And Linear Sweep Voltammetry Study Of Cyclic Tertiary Amines

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ping; TIAN JinPing; YIN YingWu

    2001-01-01

    @@ Cyclic six membered a-aminonitrile have proved to be very versatile synthetic intermediates and have been widely used in the construction of a large number of indole alkaloids. In order to obtain some information about the mechanisn of electrochemical synthesis of aaminonitrile. Electrochemistry behaviors that include cyclic voltammetry and linear sweep voltammetry of cyclic tertiary amines which including N-benzylpiperidine (NBP), 1-(l-Methoxycarbonyl ethyl) piperidine (MCEP), N-methylcarbonylppiperidine (NMCP), Nethylpiperidine(NEP) was studied.

  18. Cyclic Voltammetry And Linear Sweep Voltammetry Study Of Cyclic Tertiary Amines

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Ping

    2001-01-01

    Cyclic six membered a-aminonitrile have proved to be very versatile synthetic intermediates and have been widely used in the construction of a large number of indole alkaloids. In order to obtain some information about the mechanisn of electrochemical synthesis of aaminonitrile. Electrochemistry behaviors that include cyclic voltammetry and linear sweep voltammetry of cyclic tertiary amines which including N-benzylpiperidine (NBP), 1-(l-Methoxycarbonyl ethyl) piperidine (MCEP), N-methylcarbonylppiperidine (NMCP), Nethylpiperidine(NEP) was studied.……

  19. Some Results on Halo Research at RIBLL

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Last years,several experiments about halo nuclei were performed at RIBLL.On the analyzing and fitting the data by using Glauber theory with some assumptions,following some results were deduced.1.~8B shows a proton halo structure.The reaction cross section σR of 54 MeV/u~8B on Si was measured as 1634±49 mb.The density distribution of ~8B was studied through a fitting procedure on the enhancement of the σR at low energies including the high energy data by using Glauber theory.The result shows a long tail ...

  20. Voltammetry as a Model for Teaching Chemical Instrumentation.

    Science.gov (United States)

    Gunasingham, H.; Ang, K. P.

    1985-01-01

    Voltammetry is used as a model for teaching chemical instrumentation to chemistry undergraduates at the National University of Singapore. Lists six criteria used to select a successful teaching model and shows how voltammetry satisfies each criterion. (JN)

  1. Differential linear scan voltammetry: analytical performance in comparison with pulsed voltammetry techniques.

    Science.gov (United States)

    Sheth, Disha B; Gratzl, Miklós

    2013-06-01

    We report here on differential linear scan voltammetry, DLSV, that combines the working principles of linear scan voltammetry, LSV, and the numerous existing pulsed voltammetry techniques. DLSV preserves the information from continuous interrogation in voltage and high accuracy that LSV provides about electrochemical processes, and the much better sensitivity of differential pulsed techniques. DLSV also minimizes the background current compared to both LSV and pulsed voltammetry. An early version of DLSV, derivative stationary electrode polarography, DSEP, had been proposed in the 1960s but soon abandoned in favor of the emerging differential pulsed techniques. Relative to DSEP, DLSV takes advantage of the flexibility of discrete smoothing differentiation that was not available to early investigators. Also, DSEP had been explored in pure solutions and with reversible electrochemical reactions. DLSV is tested in this work in more challenging experimental contexts: the measurement of oxygen with a carbon fiber microelectrode in buffer, and with a gold microdisc electrode exposed to a live biological preparation. This work compares the analytical performance of DLSV and square wave voltammetry, the most popular pulsed voltammetry technique.

  2. [Occupational microclimate. Results and prospects of research].

    Science.gov (United States)

    Afanas'eva, R F; Bessonova, N A; Burmistrova, O V; Burmistrov, V M; Losik, T K

    2013-01-01

    The article covers results of studies conducted over last 15 years and aimed to elaboration of requirements to integral parameters of microclimate at workplace, its evaluation and regulation, prophylactic measures against body overcooling and overheating. The authors present methods to evaluate combined effects of physical factors (noise, vibration, microclimate) and to assess microclimate with consideration of factors determining body thermal load (energy expenditure, duration of stay at workplace, heat insulation of clothes and thermo-physical parameters of its materials). Mathematic models of forecasting cold and heat stress are presented, as well as requirements to heat insulation for individual protective means against cold and methods to calculate it. Regimens of work in heating and cooling conditions are specified. The authors set directions for further studies to define regulation requirements to microclimate on basis of studied patterns of body heat state formation, its evaluation criteria, epidemiologic studies results, specified prophylactic measures against overheating and overcooling with consideration of adaptation, sex, thermo-physical characteristics of individual protective means (special clothes, footwear, gauntlets, headwear).

  3. Voltammetry at the Thin-Film Mercury Electrode (TFME).

    Science.gov (United States)

    Pomeroy, R. S.; And Others

    1989-01-01

    Reviewed is the use of the Thin-Film Mercury Electrode for anodic stripping voltammetry, simple voltammetry of solution cations and cathodic stripping voltammetry for the determination of an environmentally important molecule, thiourea. The construction of a simple potentiostat and applications for student laboratory courses are included. (CW)

  4. Voltammetry at the Thin-Film Mercury Electrode (TFME).

    Science.gov (United States)

    Pomeroy, R. S.; And Others

    1989-01-01

    Reviewed is the use of the Thin-Film Mercury Electrode for anodic stripping voltammetry, simple voltammetry of solution cations and cathodic stripping voltammetry for the determination of an environmentally important molecule, thiourea. The construction of a simple potentiostat and applications for student laboratory courses are included. (CW)

  5. Voltammetry: mathematical modelling and Inverse Problem

    CERN Document Server

    Koshev, N A; Kuzina, V V

    2016-01-01

    We propose the fast semi-analytical method of modelling the polarization curves in the voltammetric experiment. The method is based on usage of the special func- tions and shows a big calculation speed and a high accuracy and stability. Low computational needs of the proposed algorithm allow us to state the set of Inverse Problems of voltammetry for the reconstruction of metal ions concentrations or the other parameters of the electrolyte under investigation.

  6. Mathematical Modelling of the Electrode Process of Azithromycin Using Cyclic Voltammetry at Hanging Mercury Drop Electrode

    Directory of Open Access Journals (Sweden)

    Maha F. Tutunji

    2002-11-01

    Full Text Available A theoretical treatment is presented to predict the kinetic behaviour of azithromycin at the surface of hanging mercury drop electrode using cyclic voltammetry. A model is developed to incorporate the occurrence of adsorption of the oxidized and reduced species of azithromycin at the surface of mercury drop electrode. An analytical solution was obtained using MATHEMATICA (V-3, Wolfram Research, Inc. to predict the cyclic voltammetric profiles by calculating the currents resulting after applying variable potentials ranging –1.9 to –1.3 V versus Ag/AgCl. Simulation runs at different initial concentrations of azithromycin and different scan rates showed good agreement with experimental findings. However, this model should be modified to describe a multilayer adsorption with irreversible electrochemical reaction.

  7. Reinterpretation of reduction potential measurements done by linear sweep voltammetry in silicate melts

    Science.gov (United States)

    Colson, R. O.; Haskin, L. A.; Keedy, C. R.

    1991-01-01

    The equilibrium concentrations of Ni between silicate melt and Pt were determined experimentally as a function of oxygen fugacity. The results demonstrate that metallic species derived in linear sweep voltammetry experiments in silicate melts are diffusing into Pt electrodes and not into the melt, as was concluded by previoius studies. This requires reinterpretation of previous linear sweep voltammetry results and recalculation and correction of reported reduction potentials. This paper reports these corrected reduction potentials. Also reported are the activity coefficients for Ni in synthetic basalt and diopsidic melts and for Co in diopsidic melt.

  8. Asymmetric Marcus-Hush theory for voltammetry.

    Science.gov (United States)

    Laborda, Eduardo; Henstridge, Martin C; Batchelor-McAuley, Christopher; Compton, Richard G

    2013-06-21

    The current state-of-the-art in modeling the rate of electron transfer between an electroactive species and an electrode is reviewed. Experimental studies show that neither the ubiquitous Butler-Volmer model nor the more modern symmetric Marcus-Hush model are able to satisfactorily reproduce the experimental voltammetry for both solution-phase and surface-bound redox couples. These experimental deviations indicate the need for revision of the simplifying approximations used in the above models. Within this context, models encompassing asymmetry are considered which include different vibrational and solvation force constants for the electroactive species. The assumption of non-adiabatic electron transfer is also examined. These refinements have provided more satisfactory models of the electron transfer process and they enable us to gain more information about the microscopic characteristics of the system by means of simple electrochemical measurements.

  9. Adsorptive stripping voltammetry of trimethoprim: mechanistic studies and application to the fast determination in pharmaceutical suspensions.

    Science.gov (United States)

    Carapuça, Helena M; Cabral, David J; Rocha, Luciana S

    2005-06-15

    The adsorptive stripping voltammetric behaviour of trimethoprim (TMP) was studied at pH 3.8 and 7.0 by linear-sweep (LS) and cyclic voltammetry at the hanging mercury drop electrode. The charges and surface concentrations of the protonated TMP species were determined at both pH values. Taking advantage of the adsorption features of TMP fast voltammetric techniques (LS and square-wave (SW) voltammetry) were applied to the determination of TMP at the 10(-7)mol dm(-3) concentration level (pH 3.8). For these concentrations the relative standard deviations were cathodic stripping voltammetry originated a very fast and sensitive method for the direct analysis of TMP in pharmaceutical suspensions without any matrix effects or interference from sulfamethoxazole. No sample pre-treatments or solvent extraction procedures were needed. The quantitative results were in agreement with the data supplied by the manufacturer.

  10. African Primary Care Research: quantitative analysis and presentation of results.

    Science.gov (United States)

    Mash, Bob; Ogunbanjo, Gboyega A

    2014-06-06

    This article is part of a series on Primary Care Research Methods. The article describes types of continuous and categorical data, how to capture data in a spreadsheet, how to use descriptive and inferential statistics and, finally, gives advice on how to present the results in text, figures and tables. The article intends to help Master's level students with writing the data analysis section of their research proposal and presenting their results in their final research report.

  11. African Primary Care Research: Quantitative analysis and presentation of results

    Directory of Open Access Journals (Sweden)

    Bob Mash

    2014-01-01

    Full Text Available This article is part of a series on Primary Care Research Methods. The article describes types of continuous and categorical data, how to capture data in a spreadsheet, how to use descriptive and inferential statistics and, finally, gives advice on how to present the results in text, figures and tables. The article intends to help Master’s level students with writing the data analysis section of their research proposal and presenting their results in their final research report.

  12. PRES 2013: Results from the Postgraduate Research Experience Survey

    Science.gov (United States)

    Bennett, Paul; Turner, Gosia

    2013-01-01

    This document outlines the results of the "2013 Postgraduate Research Experience Survey" ("PRES"), where 48,401 replies were received from 122 participating institutions. Redeveloped for 2013, our biennial survey is the only national survey to gather insight from postgraduate research students about their learning and…

  13. PRES 2013: Results from the Postgraduate Research Experience Survey

    Science.gov (United States)

    Bennett, Paul; Turner, Gosia

    2013-01-01

    This document outlines the results of the "2013 Postgraduate Research Experience Survey" ("PRES"), where 48,401 replies were received from 122 participating institutions. Redeveloped for 2013, our biennial survey is the only national survey to gather insight from postgraduate research students about their learning and…

  14. 48 CFR 2052.235-70 - Publication of research results.

    Science.gov (United States)

    2010-10-01

    ... publication in refereed scientific and engineering journals or dissemination to the public of any information... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Publication of research....235-70 Publication of research results. As prescribed in 2035.70(a)(1), the contracting officer...

  15. Staining of wool using the reaction products of ABTS oxidation by laccase: synergetic effects of ultrasound and cyclic voltammetry.

    Science.gov (United States)

    Munteanu, Florentina-Daniela; Basto, Carlos; Gübitz, Georg M; Cavaco-Paulo, Artur

    2007-03-01

    The effects of ultrasound on 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonate) enzymatic oxidation by laccase (Trametes villosa) has been studied by means of cyclic voltammetry. The reaction was allowed to proceed in the presence of a piece of wool and the coloration depth of the wool fabric was measured by means of K/S. It was observed that cyclic voltammetry is influenced the dyeing process and higher K/S values were obtained when the cyclic voltammetry was combined with the ultrasonic irradiation. Moreover, the K/S value is the sum of the values obtained when the wool staining is done in just the presence of cyclic voltammetry or in just the presence of ultrasound. The results obtained on the indigo carmine decolourization gives information on the importance of controlling the amount of ABTS(+) formed during the ultrasonication process.

  16. Square-wave adsorptive cathodic stripping voltammetry of pantoprazole.

    Science.gov (United States)

    Radi, A

    2003-11-24

    Adsorption and reduction of pantoprazole were investigated by cyclic and square-wave voltammetry on a hanging mercury drop electrode in Britton-Robinson buffers at pH 2.0-11.0. The reduction process gave rise to a single peak within the entire pH range. Study of the variation of the reduction signal with solution variables such as pH and concentration of pantoprazole and instrumental variables such as accumulation time and potential, frequency, pulse height and pulse amplitude, has resulted in optimization of the reduction signal for analytical purposes. The voltammetric procedure was applied successfully to give a rapid and precise assay of pantoprazole in a tablet dosage form.

  17. Export Marketing of Slavonian Kulen: the Results of Market Research

    Directory of Open Access Journals (Sweden)

    Damir Kovačić

    2003-09-01

    The results of this research are a scientifically based estimate of the export possibilities for Slavonian kulen, and they provide an information basis for the creation of an export marketing program.

  18. Export Marketing of Slavonian Kulen: the Results of Market Research

    Directory of Open Access Journals (Sweden)

    Damir Kovačić

    2003-09-01

    Full Text Available The goal of this research is to estimate the possibility of export of Slavonian kulen to foreign target markets: German, Austrian, Italian and Swiss. This research determined the administrative conditions for the export of kulen to EU, and the acceptance of the product from consumer target groups. In this research we used methods of group interview, concept test and organoleptic product test. The results of the research showed that there are no administrative obstaclesfor the export of kulen to EU. Consumer testing showed that German, Austrian and Swiss consumers like kulen, so these markets are suitable for export. Italian market already has a large offer of dried-meat products and therefore it is less suitable for the export of kulen.The results of this research are a scientifically based estimate of the export possibilities for Slavonian kulen, and they provide an information basis for the creation of an export marketing program.

  19. THE TRANSFER OF TMA+ ION AT THE WATERN NITROBENZENE INTERFACE USING SEMI-DIFFERENTIAL CYCLIC VOLTAMMETRY

    Institute of Scientific and Technical Information of China (English)

    范瑞溪; 王小平

    1990-01-01

    This paper describes the investigation of the electrochemical phenomena of TMA+ transfer at the w/nb interface using semi-differential cyclic voltammetry. The expressions for the peak potential, half-wave width and peak current are derived. All the experimental results are in good agreement with the theoretical ones.

  20. Cyclic voltammetry of fast conducting electrocatalytic films.

    Science.gov (United States)

    Costentin, Cyrille; Savéant, Jean-Michel

    2015-07-15

    In the framework of contemporary energy challenges, cyclic voltammetry is a particularly useful tool for deciphering the kinetics of catalytic films. The case of fast conducting films is analyzed, whether conduction is of the ohmic type or proceeds through rapid electron hopping. The rate-limiting factors are then the diffusion of the substrate in solution and through the film as well as the catalytic reaction itself. The dimensionless combination of the characteristics of these factors allows reducing the number of actual parameters to a maximum of two. The kinetics of the system may then be fully analyzed with the help of a kinetic zone diagram. Observing the variations of the current-potential responses with operational parameters such as film thickness, the potential scan rate and substrate concentration allows a precise assessment of the interplay between these factors and of the values of the rate controlling factors. A series of thought experiments is described in order to render the kinetic analysis more palpable.

  1. Pulse Voltammetry in Single Cells Using Platinum Microelectrodes

    Science.gov (United States)

    1991-11-22

    ring electrodes [18) in a solution of 1.OxlO’ M H2PtCl6 and 0.5 M H2SO4 and reducing platinum at 0.0 V vs SSCE for a desired deposition time. Cyclic ...E. and the range for Ed in multiple pulse voltammetry can be chosen from examination of voltammograms obtained by cyclic voltammetry or lin-ir sweep... voltametry [3,13]. As pointed out by Sinru et al. [14) the potential and time of each pulse has a direct effect on the nature of the voltammetry

  2. International Research Results and Accomplishments From the International Space Station

    Science.gov (United States)

    Ruttley, Tara M.; Robinson, Julie A.; Tate-Brown, Judy; Perkins, Nekisha; Cohen, Luchino; Marcil, Isabelle; Heppener, Marc; Hatton, Jason; Tasaki, Kazuyuki; Umemura, Sayaka; hide

    2016-01-01

    In 2016, the International Space Station (ISS) partnership published the first-ever compilation of international ISS research publications resulting from research performed on the ISS through 2011. The International Space Station Research Accomplishments: An Analysis of Results From 2000-2011 is a collection of summaries of over 1,200 journal publications that describe ISS research in the areas of biology and biotechnology; Earth and space science; educational activities and outreach; human research; physical sciences; technology development and demonstration; and, results from ISS operations. This paper will summarize the ISS results publications obtained through 2011 on behalf of the ISS Program Science Forum that is made up of senior science representatives across the international partnership. NASA's ISS Program Science office maintains an online experiment database (www.nasa.gov/issscience) that tracks and communicates ISS research activities across the entire ISS partnership, and it is continuously updated. It captures ISS experiment summaries and results and includes citations to the journals, conference proceedings, and patents as they become available. The International Space Station Research Accomplishments: An Analysis of Results From 2000-2011 is a testament to the research that was underway even as the ISS laboratory was being built. It reflects the scientific knowledge gained from ISS research, and how it impact the fields of science in both space and traditional science disciplines on Earth. Now, during a time when utilization is at its busiest, and with extension of the ISS through at least 2024, the ISS partners work together to track the accomplishments and the new knowledge gained in a way that will impact humanity like no laboratory on Earth. The ISS Program Science Forum will continue to capture and report on these results in the form of journal publications, conference proceedings, and patents. We anticipate that successful ISS research will

  3. Getting started with research "Writing-up the results of your research".

    Science.gov (United States)

    Browne, Jacinta E

    2014-02-01

    This paper gives an overview of the considerations and practical aspects of writing up the results of your research, which may be of interest to those beginning their research career or simply carrying out a research project for the first time as part of an academic qualification. It outlines practical steps for both writing up the results of your research as an academic report and thereafter disseminating your results more widely as a peer-reviewed scientific publication.

  4. Adsorptive stripping voltammetry of antibiotics rifamycin SV and rifampicin at renewable pencil electrodes.

    Science.gov (United States)

    Kawde, Abdel-Nasser; Temerk, Yassein; Farhan, Nasser

    2014-01-01

    Adsorptive stripping voltammetry of antibiotics of rifamycin SV (RSV) and rifampicin (RIF) was investigated by cyclic voltammetry and differential pulse voltammetry using a renewable pencil graphite electrode (PGE). The nature of the oxidation process of RSV and RIF taking place at the PGE was characterized. The results show that the determination of highly sensitive oxidation peak current is the basis of a simple, accurate and rapid method for quantification of RSV and RIF in bulk forms, pharmaceutical formulations and biological fluids by differential pulse adsorptive stripping voltammetry (DPASV). Factors influencing the trace measurement of RSV and RIF at PGE are assessed. The limits of detection for the determination of RSV and RIF in bulk forms are 6.0 × 10(-8) mol/L and 1.3 × 10(-8) mol/L, respectively. Moreover, the proposed procedure was successfully applied to assay both RSV and RIF in pharmaceutical formulations and in biological fluids. The capability of the proposed procedure for simultaneous assay of antibiotics RSV-isoniazid and RIF-isoniazid was achieved. The statistical analysis and calibration curve data for trace determination of RSV and RIF are reported.

  5. Stoichiometry and Formation Constant Determination by Linear Sweep Voltammetry.

    Science.gov (United States)

    Schultz, Franklin A.

    1979-01-01

    In this paper an experiment is described in which the equilibrium constants necessary for determining the composition and distribution of lead (II)-oxalate species may be measured by linear sweep voltammetry. (Author/BB)

  6. Results of a Research Evaluating Quality of Computer Science Education

    Science.gov (United States)

    Záhorec, Ján; Hašková, Alena; Munk, Michal

    2012-01-01

    The paper presents the results of an international research on a comparative assessment of the current status of computer science education at the secondary level (ISCED 3A) in Slovakia, the Czech Republic, and Belgium. Evaluation was carried out based on 14 specific factors gauging the students' point of view. The authors present qualitative…

  7. Progress and Results from the 4DH Research Centre

    DEFF Research Database (Denmark)

    Werner, Sven; Lund, Henrik; Mathiesen, Brian Vad

    2014-01-01

    and 2017, with The Danish Council for Strategic Research as main financier and the participating 31 Danish and international companies and universities as cofinanciers. Thirteen PhD student projects constitute a vital part of the research centre. In 4GDH systems, synergies are created between three areas...... of district heating and cooling, which also sum up the work of the 4DH Centre: Grids and components; Production and system integration, and Planning and implementation. This paper presents an overview of the progress and results achieved after more than two years of work. This includes the basic definition...

  8. Realization of results of innovational research in clinical oncological

    Directory of Open Access Journals (Sweden)

    A. D. Kaprin

    2015-01-01

    Full Text Available We present a brief overview of major innovative scientific research conducted at the research oncological Institute n. a. P. A. Herzen over the last decade, and the results of their the introduction into clinical practice. On the basis of 36 patents of the for the invention in Russian Federation we developed new medical technologies for diagnosis, treatment and rehabilitation of cancer patients, permission for clinical use in the territory of the Russian Federation issued by the Federal service on surveillance in healthcare and social development.

  9. The latest results from source term research. Overview and outlook

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, Luis E. [Centro de Investigaciones Energeticas Medio Ambientales y Tecnologica (CIEMAT), Madrid (Spain); Haste, Tim [Centre d' Etudes de Cadarache, Paul-Lez-Durance (France). Institut de Radioprotection et de Surete Nucleaire (IRSN); Kaerkelae, Teemu [VTT Technical Research Centre of Finland Ltd, Espoo (Finland)

    2016-12-15

    Source term research has continued internationally for more than 30 years, increasing confidence in calculations of the potential radioactive release to the environment after a severe reactor accident. Important experimental data have been obtained, mainly under international frameworks such as OECD/NEA and EURATOM. Specifically, Phebus FP provides major insights into fission product release and transport. Results are included in severe accident analysis codes. Data from international projects are being interpreted with a view to further improvements in these codes. This paper synthesizes the recent main outcomes from source term research on these topics, and on source term mitigation. It highlights knowledge gaps remaining and discusses ways to proceed. Aside from this further knowledge-driven research, there is consensus on the need to assess the source term predictive ability of current system codes, taking account of scale-up from experiment to reactor conditions.

  10. Satellite Communications for Aeronautical Applications: Recent research and Development Results

    Science.gov (United States)

    Kerczewski, Robert J.

    2001-01-01

    Communications systems have always been a critical element in aviation. Until recently, nearly all communications between the ground and aircraft have been based on analog voice technology. But the future of global aviation requires a more sophisticated "information infrastructure" which not only provides more and better communications, but integrates the key information functions (communications, navigation, and surveillance) into a modern, network-based infrastructure. Satellite communications will play an increasing role in providing information infrastructure solutions for aviation. Developing and adapting satellite communications technologies for aviation use is now receiving increased attention as the urgency to develop information infrastructure solutions grows. The NASA Glenn Research Center is actively involved in research and development activities for aeronautical satellite communications, with a key emphasis on air traffic management communications needs. This paper describes the recent results and status of NASA Glenn's research program.

  11. Sudetic larch in Germany - Results of provenance and progeny research

    Energy Technology Data Exchange (ETDEWEB)

    Weisgerber, H. [Forest Centre for Management Planning, Research and Ecology, Hann Muenden (Germany)

    1995-12-31

    There are only a few older sources of Sudetic larch in Germany. They distinguish themselves by outstanding growth and low susceptibility to canker. This impression was confirmed by results of provenance research. The Sudetic larch tested in comparison with numerous other provenances proved to be fast-growing, site-tolerant, to a large extent insusceptible to canker, with straight but also slightly to moderately curved stems. The Sudetic provenances behave remarkably uniformly as regards these characteristics. In addition to provenance research investigations have been going on for a long time in Germany into individual differences within the Sudetic larch populations. A report is given on the results of progeny tests from free and controlled pollination, using the example of a seed orchard consisting of 54 clones. We point also to possibilities for improving stem quality by selection steps. The results of provenance and progeny research on Sudetic larch are in the meantime being put to use to a large extent in practical forestry. The forest administrations of various federal lands recommend the use of reproductive material of Sudetic origin and from seed orchards. 20 refs, 3 figs

  12. Engaging Scientists and Users in Climate Change Research and Results

    Science.gov (United States)

    Cloyd, E. T.; Reeves, K.; Shimamoto, M. M.; Zerbonne, S.

    2016-12-01

    The U.S. Global Change Research Program has a mandate to "consult with actual and potential users of the results of the program" in developing products that will support learning about and responding to climate change. USGCRP has sought to engage stakeholders throughout the development and dissemination of key products, such as the Third National Climate Assessment (NCA3, 2014) and the Climate and Health Assessment (CHA, 2016), in the strategic planning processes leading to the National Global Change Research Plan (2012) and Update to the Strategic Plan (2016), and through regular postings to social media that highlight research results and opportunities for engagement. Overall, USGCRP seeks to promote dialogue between scientific experts, stakeholders, and decision makers about information needs in regions or sectors, the potential impacts of climate change, and possible responses. This presentation will describe how USGCRP has implemented various stakeholder engagement measures during the planning, development, and release of products such as NCA3 and CHA. Through repeated opportunities for stakeholder input, USGCRP has promoted process transparency and inclusiveness in the framing of assessments and other products. In addition, USGCRP has supported scientists' engagement with a range of audiences and potential collaborators through a variety of mechanisms, including community-based meetings, deliberative forums, and identification of non-Federal speaking and knowledge co-production opportunities. We will discuss key lessons learned and successful approaches for engaging users as well as opportunities and challenges for future engagement.

  13. Permafrost and periglacial research in Antarctica: New results and perspectives

    Science.gov (United States)

    Guglielmin, Mauro; Vieira, Gonçalo

    2014-11-01

    In the last two years the research within the Antarctic Permafrost, Periglacial Environments and Soils (ANTPAS) Expert Group of the Scientific Committee on Antarctic Research (SCAR) and Working Group of the International Permafrost Association (IPA) provided new results on the dynamics of periglacial environments both in Maritime and Continental Antarctica. In continental Antarctica despite the absence of air warming, in the last 15 years an active layer thickening and acceleration of permafrost degradation erosional phenomena were reported, these being mainly related to the increase of solar radiation. On the other hand, in Maritime Antarctica, with a dramatic air warming, permafrost degradation has been observed, but the role of snow cover on the ground energy balance and consequently on permafrost and active layer has been underlined. Moreover, many contributions on the knowledge on the characteristics of the Antarctic soils were carried out in several areas along a wide latitudinal range.

  14. Publishing Research Results: The Challenges of Open Access. Policy Briefing

    Science.gov (United States)

    Universities UK, 2007

    2007-01-01

    Governments, public funders of research and universities worldwide are increasingly recognising that improving the dissemination of research raises their research profile and contributes to national competitiveness. The traditional system of research publishing is inefficient, uncompetitive and restrictive. It limits access by researchers and…

  15. Some results of medical researches at Ulba Metallurgical Plant

    Energy Technology Data Exchange (ETDEWEB)

    Artemieva, G.I.; Novikov, V.G.; Savchuk, V.V. [Ulba Metallurgical Plant, Ust-Kamenogorsk (Kazakhstan)

    1998-01-01

    The results of 45-years medical researches at beryllium production of Ulba Metallurgical Plant are summarized in this report. Statistic data on different kinds of occupational diseases, related to beryllium production and the dynamics of changing occupational diseases with the development of beryllium production, are given there. Data on average duration of life of occupational disease patients are presented in the report. It includes the description of problems, related to berylliosis diagnosis. Issues, connected to beryllium production effect on health of man, located nearby beryllium production are also discussed there as well. (author)

  16. Auditing clinical research data: objectives, applications and results.

    Science.gov (United States)

    Justice, R L

    1983-01-01

    Formal auditing of clinical research data has become a standard contemporary practice within the pharmaceutical industry. Its basic purpose is to provide documentation relevant to an assessment of the quality and integrity of data collected in the course of a clinical trial. This paper outlines the audit procedures developed within one major pharmaceutical firm. These procedures require an intensive investigation of internal and external aspects of study management, records management, data entry, data analysis and statistical report preparation. A qualitative evaluation of the results achieved by this auditing procedure are presented.

  17. Analytical possibilities of microelectrode use for stripping voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Matysik, F.M. (Leipzig Univ. (Germany). Dept. of Chemistry); Glaeser, P. (Leipzig Univ. (Germany). Dept. of Chemistry); Werner, G. (Leipzig Univ. (Germany). Dept. of Chemistry)

    1994-07-01

    The analytical utility of microelectrodes for stripping voltammetry is discussed from several points of view. The application of microelectrodes for microanalysis is demonstrated using a novel capillary flow injection system. Heavy metals at [mu]g l[sup -1] concentrations have been determined in [mu]l-samples. The influence of electrode size and convection during the deposition period of anodic stripping voltammetry on the reproducibility of trace metal determination was studied for various types of electrodes. In the case of mercury film microelectrodes, the precision can be improved if the accumulation of the analyte is performed under quiescent conditions. Practical examples of stripping voltammetry with microelectrodes such as copper determination in whisky and trace metal measurements in drinking water are given. (orig.)

  18. Manganese detection in marine sediments: anodic vs. cathodic stripping voltammetry.

    Science.gov (United States)

    Banks, Craig E; Kruusma, Jaanus; Moore, Ryan R; Tomcík, Peter; Peters, Judith; Davis, James; Komorsky-Lovrić, Sebojka; Compton, Richard G

    2005-01-30

    Three different electroanalytical techniques for the detection of manganese in marine sediments are evaluated. The anodic stripping voltammetry of manganese at an in situ bismuth-film-modified boron-doped diamond electrode and cathodic stripping voltammetry at a carbon paste electrode are shown to lack the required sensitivity and reproducibility whereas cathodic stripping voltammetry at a bare boron-doped diamond electrode is shown to be reliable and selective with a limit of detection, from applying a 60s accumulation period of 7.4 x 10(-7)M and a sensitivity of 0.24AM(-1). The method was used to evaluate the manganese content of marine sediments taken from Sibenik, Croatia.

  19. What Will Classroom Teachers Do With Shared Research Results?

    Science.gov (United States)

    Passow, M. J.; Weissel, J. K.; Cormier, M.; Newman, K. R.

    2005-12-01

    Scientists are passionate about the research problems they investigate, and wish to share their discoveries as widely as possible. Similarly, classroom teachers who are passionate about their subject can better foster student learning. One way to enhance such passions involves bringing teachers and scientists together to discuss cutting-edge discoveries and develop curricular materials based on the respective strengths of educators and investigators. Our presentation describes one example of this approach based on research about gas blowout structures offshore Virginia and North Carolina. Methane venting processes along continental margins may have important climatic, geotechnical, hazard, and resource implications. In 2000, shipboard surveys documented that large structures offshore VA-NC resulted from massive gas expulsion. Gas appears to be trapped in shelf edge deltas and stresses resulting from downslope creep is favoring its release. Scientists undertook a new expedition in 2004 to determine if there is present-day discharge of methane-rich fluids through the floors or walls of the blowouts or whether these seepage sites are relict features, and to gain insight into the origin of the vented methane. In July 2005, 12 teachers from New York and New Jersey met with the co-PIs (Weissel and Cormier), graduate student (Newman), and educational specialist (Passow) over a 2-day workshop to learn about how scientific problems are identified, how a research cruise is organized, what was learned through the measurements and analysis, and what might be possible significant impacts from such understandings. Based on what they learned, participants began development of classroom activities, Internet-based investigations, and constructed-response assessment items utilizing data and concepts from the project and other sources. The resulting curriculum units are designed for use in middle and high school chemistry, physics, earth science, and technology courses. Curricular

  20. Cyclic voltammetry and RBS study of paint components

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Lynn [Center for Irradiation of Materials, Alabama A and M University, 4900 Meridian Street, P.O. Box 1447, Normal, AL 35762 (United States); Spencer, Dirk [Plant and Soil Science Department, Alabama A and M University, Normal, AL 35762-1447 (United States); Muntele, Claudiu [Center for Irradiation of Materials, Alabama A and M University, 4900 Meridian Street, P.O. Box 1447, Normal, AL 35762 (United States)]. E-mail: claudiu@cim.aamu.edu; Muntele, Iulia [Center for Irradiation of Materials, Alabama A and M University, 4900 Meridian Street, P.O. Box 1447, Normal, AL 35762 (United States); Ila, D. [Center for Irradiation of Materials, Alabama A and M University, 4900 Meridian Street, P.O. Box 1447, Normal, AL 35762 (United States)

    2007-08-15

    Heavy metals and metalloid ions are found in environmental matrices. The most toxic are lead, cadmium and mercury. These three heavy metals have no biological function and are toxic at all concentrations. Lead is one of the most insidious heavy metals and is introduced into the environment by many different means. It persists in both urban and rural settings, being found in paint chips, pottery, crystal and pharmaceutical and nutritional products. The analysis of heavy elements such as lead in soil is of particular importance [W.T. Sturges, R.M. Harrison, Sci. Total Environ. 44 (3) (1985) 225; M.L. Lepow, L. Bruckman, M. Gillette, S. Markowitz, R. Robino, J. Kapish, Environ. Res. 10 (3) (1975) 415; A.E. Daniels, J.R. Kominsky, P.J. Clark, J. Hazard. Mater. B 87 (2001) 117; G. Hutter, D. Moshman, J. Hazard. Mater. 40 (1995) 1]. In preparing the methods for lead detection in paint, we have used Rutherford backscattering spectrometry (RBS) in order to study the type and amount of heavy metal content in paint samples collected at various sites in the historic campus at A and M University (AAMU). We will show the results of our study with emphasis on comparison of what we learned about presence of lead in paints using our ion beam methods compared with the analysis of lead in paints using cyclic voltammetry.

  1. Voltammetry of redox analytes at trace concentrations with nanoelectrode ensembles.

    Science.gov (United States)

    Moretto, Ligia Maria; Pepe, Niki; Ugo, Paolo

    2004-04-19

    Gold nanoelectrodes ensembles (NEEs) have been prepared by electroless plating of Au nanoelectrode elements within the pores of a microporous polycarbonate template membrane. Cyclic voltammograms recorded in (ferrocenylmethyl) trimethylammonium hexafluorophosphate (FA(+) PF(6)(-)) solutions showed that these NEEs operate in the "total-overlap" response regime, giving well resolved peak shaped voltammograms. Experimental results show that the faradaic/background currents ratios at the NEE are independent on the total geometric area of the ensemble, so that NEE can be enlarged or miniaturized at pleasure without influencing the very favorable signal/noise ratio. Differential pulse voltammetry (DPV) at the NEE is optimized for direct determinations at trace levels. DPV at NEE allowed the determination (with no preconcentration) of trace amounts of FA(+), with a detection limit of 0.02muM. The use of NEE and DPV in cytochrome c (cyt c) solutions showed the possibility to observe the direct electrochemistry of submicromolar concentration of the protein, even without the need of adding any promoter or mediator.

  2. Results of a Research Evaluating Quality of Computer Science Education

    Directory of Open Access Journals (Sweden)

    Ján ZÁHOREC

    2012-10-01

    Full Text Available The paper presents the results of an international research on a comparative assessment of the current status of computer science education at the secondary level (ISCED 3A in Slovakia, the Czech Republic, and Belgium. Evaluation was carried out based on 14 specific factors gauging the students' point of view. The authors present qualitative findings from the following nine analyzed factors: the popularity of computer science/informatics as a subject, the potential of using knowledge gained by studying informatics at school in everyday life, the attractiveness and demands of the curriculum content, the clarity and attractiveness of teacher presentation of the subject matter to students, the engagement of tasks solved while studying informatics, the degree of comprehensibility of informatics textbooks, and the usability of knowledge acquired in school for solving practical problems. Based on the results, the authors identify the strengths and weaknesses of computer science education in the observed countries.

  3. Nonlinear random vibration experimental results and research needs

    Science.gov (United States)

    Ibrahim, R. A.

    Experimental investigations of random excitation of dynamic systems are valuable but scarce. They are particularly important for nonlinear random vibration, since different approaches can lead to different results for the same problem. They are also useful in providing physical insight into a number of complex dynamic phenomena. The scarcity of random vibration testing is mainly due to a number of difficulties and errors encountered in generating the correct random excitation, and data acquisition. The purpose of this review article is to assess the recent experimental results reported in the literature by the author and others. An attempt will be made to correlate the experimental measurements qualitatively with those predicted analytically. In most cases, no quantitative comparisons have been made. New research directions based on recent analytical and experimental developments in the theory of nonlinear random vibration will also be outlined.

  4. Determination of mobile form contents of Zn, Cd, Pb and Cu in soil extracts by combined stripping voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Nedeltcheva, T. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria)]. E-mail: nedel@uctm.edu; Atanassova, M. [Department of Analytical Chemistry, University of Chemical Technology and Metallurgy, 8 Kl. Ohridsi Blvd., 1756 Sofia (Bulgaria); Dimitrov, J. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria); Stanislavova, L. [N. Pushkarov Institute of Soil Science and Agroecology, 7 Shosse Bankya St., 1080 Sofia (Bulgaria)

    2005-01-10

    The amount of mobile forms of Zn, Pb, Cd and Cu in extracts obtained by treating soil samples with ammonium nitrate were determined by an appropriate combination of anodic and cathodic stripping voltammetry with hanging mercury drop electrode. Every analysis required three mercury drops: on the first one, zinc was determined; on the second, cadmium and lead; on the third, copper was determined. Zinc, lead and cadmium were determined by conventional differential-pulse anodic stripping voltammetry. For copper determination, adsorptive differential-pulse cathodic stripping voltammetry with amalgamation using chloride ions as a complexing agent was applied. The standard deviation of the results was from 1 to 10% depending on the metal content in the sample. Voltammetric results were in good agreement with the AAS analysis. No microwave digestion of soil extracts was necessary.

  5. Study on the adsorptive catalytic voltammetry of aloe-emodin at a carbon paste electrode

    Institute of Scientific and Technical Information of China (English)

    LI; Ju'nan; GAO; Peng; LI; Xiangling; YAN; Zhihong; MAO; Xu

    2005-01-01

    A new catalytic voltammetric method for the determination of anthraqunone medicines at a carbon paste electrode (CPE) was described for the first time. The mechanism of the catalytic reaction was investigated by using linear sweep voltammetry, cyclic voltammetry, constant potential electrolysis and so on. The experiment results indicate that aloe-emodin was efficiently accumulated at a CPE by adsorption. In the following potential scan, aloe-emodin was reduced to homologous anthrahydroquinone compound, then the compound was immediately oxidized to aloe-emodin by the dissolved oxygen, and the aloe-emodin was again reduced at the CPE. As a result, a cyclic catalytic reaction was established. But a reversible redox reaction of aloe-emodin can only be observed at a mercury electrode, no catalytic reaction occurs there. A sensitive catalytic voltammetric peak of aloe-emodin was obtained at about -0.60 V (vs. SCE) in 0.56 mol/L NH3-NH4Cl buffer (pH 8.9). The proposed method was applied to the determination of aloe-emodin in the Radix Rhei with satisfactory results. The determination results were in good agreement with reference values obtained by the HPLC. The adsorptive catalytic voltammetry for the determination of organic compound at CPE, chemically modified electrode and other solid electrodes could be significant in the studies on pharmacology, pharmacodynamics, toxicity of medicine, clinical medicine and biochemistry.

  6. Hairy carbon electrodes studied by cyclic voltammetry and battery discharge testing

    Science.gov (United States)

    Chung, Deborah D. L.; Shui, Xiaoping; Frysz, Christine A.

    1993-01-01

    Hairy carbon is a new material developed by growing submicron carbon filaments on conventional carbon substrates. Typical substrate materials include carbon black, graphite powder, carbon fibers, and glassy carbon. A catalyst is used to initiate hair growth with carbonaceous gases serving as the carbon source. To study the electrochemical behavior of hairy carbons, cyclic voltammetry (CV) and discharge testing were conducted. In both cases, hairy carbon results surpassed those of the substrate material alone.

  7. A pipette-based calibration system for fast-scan cyclic voltammetry with fast response times.

    Science.gov (United States)

    Ramsson, Eric S

    2016-01-01

    Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique that utilizes the oxidation and/or reduction of an analyte of interest to infer rapid changes in concentrations. In order to calibrate the resulting oxidative or reductive current, known concentrations of an analyte must be introduced under controlled settings. Here, I describe a simple and cost-effective method, using a Petri dish and pipettes, for the calibration of carbon fiber microelectrodes (CFMs) using FSCV.

  8. Cathodic stripping voltammetry of trace Mn(II) at carbon film electrodes

    OpenAIRE

    Filipe, Olga M. S.; Brett,Christopher M.A.

    2003-01-01

    A sensitive voltammetric method is presented for the determination of tract levels of Mn (II) using carbon film electrodes fabricated from carbon resistors of 2 [Omega]. Determination of manganese was made by square wave cathodic stripping voltammetry (CSV), with deposition of manganese as manganese dioxide. Chronoamperometric experiments were made to study MnO2 nucleation and growth. As a result, it was found to be necessary to perform electrode conditioning at a more positive potential to i...

  9. Preparation and Cyclic Voltammetry Characterization Of Cu-dipyridyl Imprinted Polymer

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Polymer capable of specific binding to Cu-dipyridyl complex was prepared by molecular imprinting technology.The binding specificity of the polymer to the template (Cu-dipyridyl complex) was investigated by cyclic voltametric scanning using the carbon paste electrode modified by polymer particles in phosphate buffer solution.Factors that influence rebinding of the imprinted polymer were explored.The result demonstrated that the cyclic voltammetry was an efficient approach to explore interactions between template and imprinted polymers.

  10. Results of Chilean water markets: Empirical research since 1990

    Science.gov (United States)

    Bauer, Carl J.

    2004-09-01

    Chile's free-market Water Code turned 20 years old in October 2001. This anniversary was an important milestone for both Chilean and international debates about water policy because Chile has become the world's leading example of the free-market approach to water law and water resources management, the textbook case of treating water rights not merely as private property but also as a fully marketable commodity. The predominant view outside of Chile is that Chilean water markets and the Chilean model of water management have been a success, and this perception has encouraged other countries to follow Chile's lead in water law reform. Much of the debate about Chilean water markets, however, has been based more on theoretical or political beliefs than on empirical study. This paper reverses that emphasis by reviewing the evolution of empirical research about these markets since 1990, when Chile returned to democratic government after 16 years of military rule. During the period since 1990, understanding of how Chilean water markets have worked in practice has gradually improved. There have been two major trends in this research: first, a gradual shift from exaggerated claims of the markets' success toward more balanced assessments of mixed results and, second, a heavy emphasis on the economics of water rights trading with very little attention given to the Water Code's impacts on social equity, river basin management, environmental protection, or resolution of water conflicts. The analysis in this study is qualitative and interdisciplinary, combining law, economics, and institutions.

  11. Hitchhiker's Guide to Voltammetry: Acute and Chronic Electrodes for in Vivo Fast-Scan Cyclic Voltammetry.

    Science.gov (United States)

    Rodeberg, Nathan T; Sandberg, Stefan G; Johnson, Justin A; Phillips, Paul E M; Wightman, R Mark

    2017-02-15

    Fast-scan cyclic voltammetry (FSCV) has been used for over 20 years to study rapid neurotransmission in awake and behaving animals. These experiments were first carried out with carbon-fiber microelectrodes (CFMs) encased in borosilicate glass, which can be inserted into the brain through micromanipulators and guide cannulas. More recently, chronically implantable CFMs constructed with small diameter fused-silica have been introduced. These electrodes can be affixed in the brain with minimal tissue response, which permits longitudinal measurements of neurotransmission in single recording locations during behavior. Both electrode designs have been used to make novel discoveries in the fields of neurobiology, behavioral neuroscience, and psychopharmacology. The purpose of this Review is to address important considerations for the use of FSCV to study neurotransmitters in awake and behaving animals, with a focus on measurements of striatal dopamine. Common issues concerning experimental design, data collection, and calibration are addressed. When necessary, differences between the two methodologies (acute vs chronic recordings) are discussed. The topics raised in this Review are particularly important as the field moves beyond dopamine toward new neurochemicals and brain regions.

  12. Detection of food additives by voltammetry at the liquid-liquid interface.

    Science.gov (United States)

    Herzog, Grégoire; Kam, Victor; Berduque, Alfonso; Arrigan, Damien W M

    2008-06-25

    Electrochemistry at the liquid-liquid interface enables the detection of nonredoxactive species with electroanalytical techniques. In this work, the electrochemical behavior of two food additives, aspartame and acesulfame K, was investigated. Both ions were found to undergo ion-transfer voltammetry at the liquid-liquid interface. Differential pulse voltammetry was used for the preparation of calibration curves over the concentration range of 30-350 microM with a detection limit of 30 microM. The standard addition method was applied to the determination of their concentrations in food and beverage samples such as sweeteners and sugar-free beverages. Selective electrochemically modulated liquid-liquid extraction of these species in both laboratory solutions and in beverage samples was also demonstrated. These results indicate the suitability of liquid-liquid electrochemistry as an analytical approach in food analysis.

  13. Electrochemical-Voltammetry Behavior of Several Aromatic Aldehydes in Acid Solution

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The electrochemical-voltammetry behavior of vanillin, heliotropin, anisaldehyde on the surface ofPt, Au electrodes in acid solution has been studied by means of the electrochemical cyclic voltammetry method. I was found that the electrochemical processes of them are irreversible on both Pt and Au elec-trodes. The electrochemical activity of vanillin is stronger than heliotropin's and heliotropin's is stronger than, anisaldehyde's on Pt electrode. While the electrochemical activity of anisaldehyde is stronger than heliotropin's and vanillin's is the weakest on Au. The results indicate that when they are used as additives for electroplating, they must be consumptive, and it will improve the leveling ability of plating solution and brightness of the deposition layer.

  14. Facilitated ion transfer of protonated primary organic amines studied by square wave voltammetry and chronoamperometry.

    Science.gov (United States)

    Torralba, E; Ortuño, J A; Molina, A; Serna, C; Karimian, F

    2014-05-15

    The transfer of the protonated forms of heptylamine, octylamine, decylamine, procaine and procainamide facilitated by dibenzo-18-crown-6 from water to a solvent polymeric membrane has been investigated by using cyclic square wave voltammetry. The experimental voltammograms obtained are in good agreement with theoretical predictions. The values of the standard ion transfer potential, complexation constant and diffusion coefficient in water have been obtained from these experiments, and have been used to draw some conclusions about the lipophilicity of these species and the relative stability of the organic ammonium complexes with dibenzo-18-crown-6. The results have been compared with those provided by linear sweep voltammetry. Calibration graphs were obtained with both techniques. An interesting chronoamperometric method for the determination of the diffusion coefficient of the target ion in the membrane has been developed and applied to all these protonated amines.

  15. Voltametria de onda quadrada. Segunda parte: aplicações Square wave voltammetry. Second part: applications

    Directory of Open Access Journals (Sweden)

    Djenaine de Souza

    2004-10-01

    Full Text Available The aim of this work is to discuss some selected applications of square wave voltammetry published in the last five years. The applications focused here cover several electroanalytical fields such as: determination of pesticides; molecules with biological activity; metals and other environmental pollutants. Special attention is given to the work developed in the Grupo de Materiais Eletroquímicos e Métodos Eletroanalíticos - IQSC - USP concerning the utilization of square wave voltammetry, with different kinds of electrodes, for the determination of pesticides in natural waters and active principles in pharmaceutical formulations. The new methodology is simple, fast and sensitive when compared with the traditional ones such as chromatography and spectrophotometry. The satisfactory results obtained provide alternative procedures for the quality control of drugs and the monitoring of pesticides in natural environments.

  16. Changes in science classrooms resulting from collaborative action research initiatives

    Science.gov (United States)

    Oh, Phil Seok

    Collaborative action research was undertaken over two years between a Korean science teacher and science education researchers at the University of Iowa. For the purpose of realizing science learning as envisioned by constructivist principles, Group-Investigations were implemented three or five times per project year. In addition, the second year project enacted Peer Assessments among students. Student perceptions of their science classrooms, as measured by the Constructivist Learning Environment Survey (CLES), provided evidence that the collaborative action research was successful in creating constructivist learning environments. Student attitudes toward science lessons, as examined by the Enjoyment of Science Lessons Scale (ESLS), indicated that the action research also contributed to developing more positive attitudes of students about science learning. Discourse analysis was conducted on video-recordings of in-class presentations and discussions. The results indicated that students in science classrooms which were moving toward constructivist learning environments engaged in such discursive practices as: (1) Communicating their inquiries to others, (2) Seeking and providing information through dialogues, and (3) Negotiating conflicts in their knowledge and beliefs. Based on these practices, science learning was viewed as the process of constructing knowledge and understanding of science as well as the process of engaging in scientific inquiry and discourse. The teacher's discursive practices included: (1) Wrapping up student presentations, (2) Addressing misconceptions, (3) Answering student queries, (4) Coaching, (5) Assessing and advising, (6) Guiding students discursively into new knowledge, and (7) Scaffolding. Science teaching was defined as situated acts of the teacher to facilitate the learning process. In particular, when the classrooms became more constructivist, the teacher intervened more frequently and carefully in student activities to fulfill a

  17. Organic Eprints – Helping research results go to work

    DEFF Research Database (Denmark)

    Rasmussen, Ilse Ankjær; Jensen, Allan Leck; Willer, Helga

    2014-01-01

    Ninety certified organic pineapple producers were interviewed using a semi-structured questionnaire in Luwero and Kayung districts in Uganda. Data was analysed using statistical package for Social Scientists (SPSS). Results indicated that most organic farmers (81.1%) kept mostly cattle....... The future prospects of integrated organic systems and development of organic livestock production lies in research developing sustainable solutions suitable for organic systems. In addition to organic farmers giving more focus to livestock production for purposes of producing quality animal products...... for niche organic markets, household nutrition and improving on crop production. Government and private sector needs to consider investment in infrastructural development, improving farmer’s knowledge and providing appropriate inputs....

  18. Catalytic mechanism in cyclic voltammetry at disc electrodes: an analytical solution.

    Science.gov (United States)

    Molina, Angela; González, Joaquín; Laborda, Eduardo; Wang, Yijun; Compton, Richard G

    2011-08-28

    The theory of cyclic voltammetry at disc electrodes and microelectrodes is developed for a system where the electroactive reactant is regenerated in solution using a catalyst. This catalytic process is of wide importance, not least in chemical sensing, and it can be characterized by the resulting peak current which is always larger than that of a simple electrochemical reaction; in contrast the reverse peak is always relatively diminished in size. From the theoretical point of view, the problem involves a complex physical situation with two-dimensional mass transport and non-uniform surface gradients. Because of this complexity, hitherto the treatment of this problem has been tackled mainly by means of numerical methods and so no analytical expression was available for the transient response of the catalytic mechanism in cyclic voltammetry when disc electrodes, the most popular practical geometry, are used. In this work, this gap is filled by presenting an analytical solution for the application of any sequence of potential pulses and, in particular, for cyclic voltammetry. The induction principle is applied to demonstrate mathematically that the superposition principle applies whatever the geometry of the electrode, which enabled us to obtain an analytical equation valid whatever the electrode size and the kinetics of the catalytic reaction. The theoretical results obtained are applied to the experimental study of the electrocatalytic Fenton reaction, determining the rate constant of the reduction of hydrogen peroxide by iron(II).

  19. Integrated flight propulsion control research results using the NASA F-15 HIDEC Flight Research Facility

    Science.gov (United States)

    Stewart, James F.

    1992-01-01

    Over the last two decades, NASA has conducted several flight research experiments in integrated flight propulsion control. Benefits have included increased thrust, range, and survivability; reduced fuel consumption; and reduced maintenance. These flight programs were flown at NASA Dryden Flight Research Facility. This paper presents the basic concepts for control integration, examples of implementation, and benefits of integrated flight propulsion control systems. The F-15 research involved integration of the engine, flight, and inlet control systems. Further extension of the integration included real time, onboard optimization of engine, inlet, and flight control variables; a self repairing flight control system; and an engines only control concept for emergency control. The flight research programs and the resulting benefits are described for the F-15 research.

  20. [Recent results in research on oscillatory chemical reactions].

    Science.gov (United States)

    Poros, Eszter; Kurin-Csörgei, Krisztina

    2014-01-01

    The mechanisms of the complicated periodical phenomenas in the nature (e.g. hearth beat, sleep cycle, circadian rhythms, etc) could be understood with using the laws of nonlinear chemical systems. In this article the newest result in the research of the subfield of nonlinear chemical dynamics aimed at constructing oscillatory chemical reactions, which are novel either in composition or in configuration, are presented. In the introductory part the concept of chemical periodicity is defined, then the forms as it can appear in time and space and the methods of their study are discussed. Detailed description of the experimental work that has resulted in two significant discoveries is provided. A method was developed to design pH-oscillators which are capable of operating under close conditions. The batch pH-oscillators are more convenient to use in some proposed applications than the equivalent CSTR variant. A redox oscillator that is new in composition was found. The permanganate oxidation of some amino acids was shown to take place according to oscillatory kinetics in a narrow range of the experimental parameters. The KMnO4 - glycine - Na2HPO4 system represents the first example in the family of manganese based oscillators where amino acids is involved. In the conclusion formal analogies between the simple chemical and some more complicated biological oscillatory phenomena are mentioned and the possibility of modeling periodic processes with the use of information gained from the studies of chemical oscillations is pointed out.

  1. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

    DEFF Research Database (Denmark)

    Alatraktchi, Fatima AlZahra'a; Andersen, Sandra Breum; Johansen, Helle Krogh;

    2016-01-01

    method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between -1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58-0.82 V that is unaffected by other redox-active interferents...

  2. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

    DEFF Research Database (Denmark)

    Al Atraktchi, Fatima Al-Zahraa; Breum Andersen, Sandra; Johansen, Helle Krogh;

    2016-01-01

    method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between –1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58–0.82 V that is unaffected by other redox-active interferents...

  3. Differential cyclic voltammetry for selective and amplified detection

    NARCIS (Netherlands)

    Megen, M.J.J; Odijk, M.; Wiedemair, J.; Olthuis, W.; Berg, van den A.

    2012-01-01

    We propose to combine two existing electrochemical techniques, cyclic voltammetry (CV) and redox cycling (RC), in order to obtain amplified and selective detection of redox active species. This combination is achieved by applying CV waveforms to two electrodes spaced 1.20 mu m apart, with one of the

  4. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

    DEFF Research Database (Denmark)

    Alatraktchi, Fatima AlZahra'a; Andersen, Sandra Breum; Johansen, Helle Krogh

    2016-01-01

    method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between -1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58-0.82 V that is unaffected by other redox-active interferents...

  5. Differential cyclic voltammetry for selective and amplified detection

    NARCIS (Netherlands)

    van Megen, M.J.J.; Odijk, Mathieu; Wiedemair, Justyna; Olthuis, Wouter; van den Berg, Albert

    2012-01-01

    We propose to combine two existing electrochemical techniques, cyclic voltammetry (CV) and redox cycling (RC), in order to obtain amplified and selective detection of redox active species. This combination is achieved by applying CV waveforms to two electrodes spaced 1.20 mu m apart, with one of the

  6. A Cyclic Voltammetry Experiment for the Instrumental Analysis Laboratory.

    Science.gov (United States)

    Baldwin, Richard P.; And Others

    1984-01-01

    Background information and procedures are provided for experiments that illustrate the nature of cyclic voltammetry and its application in the characterization of organic electrode processes. The experiments also demonstrate the concepts of electrochemical reversibility and diffusion-controlled mass transfer. (JN)

  7. A Cyclic Voltammetry Experiment for the Instrumental Analysis Laboratory.

    Science.gov (United States)

    Baldwin, Richard P.; And Others

    1984-01-01

    Background information and procedures are provided for experiments that illustrate the nature of cyclic voltammetry and its application in the characterization of organic electrode processes. The experiments also demonstrate the concepts of electrochemical reversibility and diffusion-controlled mass transfer. (JN)

  8. Square wave voltammetry at the dropping mercury electrode: Theory

    Science.gov (United States)

    Christie, J.H.; Turner, J.A.; Osteryoung, R.A.

    1977-01-01

    The theoretical aspects of square wave voltammetry at the dropping mercury electrode are presented. The technique involves scanning the entire potential range of interest on a single drop of a DME. Asymmetries in the waveform as well as variations in current measurement parameters are discussed. Indications are that previous uses of the waveform may not have utilized all its capabilities.

  9. Characterization of an electrochemical mercury sensor using alternating current, cyclic, square wave and differential pulse voltammetry.

    Science.gov (United States)

    Guerreiro, Gabriela V; Zaitouna, Anita J; Lai, Rebecca Y

    2014-01-31

    Here we report the characterization of an electrochemical mercury (Hg(2+)) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a "signal-off" sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a "signal-off" or "signal-on" sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed "signal-on" behavior at low frequencies and "signal-off" behavior at high frequencies. In DPV, the sensor showed "signal-off" behavior at short pulse widths and "signal-on" behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10nM, with a linear dynamic range between 10nM and 500nM. In addition, the sensor responded to Hg(2+) rather rapidly; majority of the signal change occurred in <20min. Overall, the sensor retains all the characteristics of this class of sensors; it is reagentless, reusable, sensitive, specific and selective. This study also highlights the feasibility of using a MB-modified probe for real-time sensing of Hg(2+), which has not been previously reported. More importantly, the observed "switching" behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Alternating current scanning electrochemical microscopy with simultaneous fast-scan cyclic voltammetry.

    Science.gov (United States)

    Koch, Jason A; Baur, Melinda B; Woodall, Erica L; Baur, John E

    2012-11-06

    Fast-scan cyclic voltammetry (FSCV) is combined with alternating current scanning electrochemical microscopy (AC-SECM) for simultaneous measurements of impedance and faradaic current. Scan rates of 10-1000 V s(-1) were used for voltammetry, while a high-frequency (100 kHz), low-amplitude (10 mV rms) sine wave was added to the voltammetric waveform for the ac measurement. Both a lock-in amplifier and an analog circuit were used to measure the amplitude of the resultant ac signal. The effect of the added sine wave on the voltammetry at a carbon fiber electrode was investigated and found to have negligible effect. The combined FSCV and ac measurements were used to provide simultaneous chemical and topographical information about a substrate using a single carbon fiber probe. The technique is demonstrated in living cell culture, where cellular respiration and topography were simultaneously imaged without the addition of a redox mediator. This approach promises to be useful for the topographical and multidimensional chemical imaging of substrates.

  11. Development of a cyclic voltammetry method for the detection of Clostridium novyi in black disease.

    Science.gov (United States)

    Liu, L L; Jiang, D N; Xiang, G M; Liu, C; Yu, J C; Pu, X Y

    2014-03-17

    Black disease is an acute disease of sheep and cattle. The pathogen is the obligate anaerobe, Clostridium novyi. Due to difficulties of anaerobic culturing in the country or disaster sites, a simple, rapid, and sensitive method is required. In this study, an electrochemical method, the cyclic voltammetry method, basing on loop-mediated isothermal amplification (LAMP), electrochemical ion bonding (positive dye, methylene blue), was introduced. DNA extracted from C. novyi specimens was amplified through the LAMP reaction. Then the products combined were with methylene blue, which lead to a reduction in the oxidation peak current (ipA) and the reduction peak current (ipC) of the cyclic voltammetry. The changes of ipA/ipC were real-time measured by special designed electrode, so the DNA was quantitatively detected. The results displayed that this electrochemical detection of C. novyi could be completed in 1-2 h with the lowest bacterial concentration of 10(2) colony forming units/mL, and high accuracy (96.5%), sensitivity (96%), and specificity (97%) compared to polymerase chain reation. The cyclic voltammetry method was a simple and fast method, with high sensitivity and high specificity, and has great potential to be a usable molecular tool for fast diagnosis of Black disease.

  12. Electrochemical characterisation and anodic stripping voltammetry at mesoporous platinum rotating disc electrodes.

    Science.gov (United States)

    Lozano-Sanchez, Pablo; Elliott, Joanne M

    2008-02-01

    Using the technique of liquid crystal templating a rotating disc electrode (RDE) was modified with a high surface area mesoporous platinum film. The surface area of the electrode was characterised by acid voltammetry, and found to be very high (ca. 86 cm(2)). Acid characterisation of the electrode produced distorted voltammograms was interpreted as being due to the extremely large surface area which produced a combination of effects such as localised pH change within the pore environment and also ohmic drop effects. Acid voltammetry in the presence of two different types of surfactant, namely Tween 20 and Triton X-100, suggested antifouling properties associated with the mesoporous deposit. Further analysis of the modified electrode using a redox couple in solution showed typical RDE behaviour although extra capacitive currents were observed due to the large surface area of the electrode. The phenomenon of underpotential deposition was exploited for the purpose of anodic stripping voltammetry and results were compared with data collected for microelectrodes. Underpotential deposition of metal ions at the mesoporous RDE was found to be similar to that at conventional platinum electrodes and mesoporous microelectrodes although the rate of surface coverage was found to be slower at a mesoporous RDE. It was found that a mesoporous RDE forms a suitable system for quantification of silver ions in solution.

  13. Optimizing the Temporal Resolution of Fast-Scan Cyclic Voltammetry

    Science.gov (United States)

    2012-01-01

    Electrochemical detection with carbon-fiber microelectrodes has become an established method to monitor directly the release of dopamine from neurons and its uptake by the dopamine transporter. With constant potential amperometry (CPA), the measured current provides a real time view of the rapid concentration changes, but the method lacks chemical identification of the monitored species and markedly increases the difficulty of signal calibration. Monitoring with fast-scan cyclic voltammetry (FSCV) allows species identification and concentration measurements but often exhibits a delayed response time due to the time-dependent adsorption/desorption of electroactive species at the electrode. We sought to improve the temporal resolution of FSCV to make it more comparable to CPA by increasing the waveform repetition rate from 10 to 60 Hz with uncoated carbon-fiber electrodes. The faster acquisition led to diminished time delays of the recordings that tracked more closely with CPA measurements. The measurements reveal that FSCV at 10 Hz underestimates the normal rate of dopamine uptake by about 18%. However, FSCV collection at 10 and 60 Hz provide identical results when a dopamine transporter (DAT) blocker such as cocaine is bath applied. To verify further the utility of this method, we used transgenic mice that overexpress DAT. After accounting for the slight adsorption delay time, FSCV at 60 Hz adequately monitored the increased uptake rate that arose from overexpression of DAT and, again, was similar to CPA results. Furthermore, the utility of collecting data at 60 Hz was verified in an anesthetized rat by using a higher scan rate (2400 V/s) to increase sensitivity and the overall signal. PMID:22708011

  14. Results of microbial research of environment of international space station

    Science.gov (United States)

    Novikova, N.; Poddubko, S.; Deshevaya, E.; Polikarpov, N.; Rakova, N.

    Many years of exploitation of orbital space stations have moved forward ecological problems among which microbial society of the environment plays a most important role. Qualitative and quantitative characteristics of microorganisms in the environment of a space object can change considerably under the influence of conditions of space flight. In the process of exploitation of the International Space Station (ISS) microflora of air, interior surfaces and equipment is monitored on a regular basis to keep continuous assessment of sanitary and microbiological state of the environment. Up to the present time 32 species of microorganisms have been recovered in the ISS, namely 15species f bacteria and 17 species of moldy fungi. In the composition of microbial species mainly nonpathogenic species have been found. However, a number of bacteria discovered on the ISS, particularly some representatives of human microflora, are capable of causing different diseases when human immune system is compromised. Moreover, some bacteria and a considerable number of fungi are known to be potential biodestructors of construction materials, which leads to biodeterioration of construction materials and equipment. Results of our research show that the existing set of life-supporting systems can maintain microbial contamination within regulated levels. Furthermore, constant microbial monitoring of the environment is an integral part, which provides for the safety of space missions.

  15. 2005 Mobility of Transfer Students in BC. Research Results

    Science.gov (United States)

    Holubeshen, Moufida; Cowin, Bob; Gaber, Devron

    2006-01-01

    This 8-page document outlines the key findings of research conducted to assess the number and proportion of potential transfer students from Fall 2004 who subsequently registered at BC universities in 2005, as well as the mobility patterns of these students among all public post-secondary institutions in BC. The research was initiated to assist BC…

  16. Attitudes of Research Participants and the General Public Regarding Disclosure of Alzheimer Disease Research Results

    Science.gov (United States)

    Gooblar, Jonathan; Roe, Catherine M.; Selsor, Natalie J.; Gabel, Matthew J.; Morris, John C.

    2015-01-01

    IMPORTANCE Results of Alzheimer disease (AD) research assessments typically are not disclosed to participants. Recent research has suggested interest in disclosure, but, to our knowledge, few studies have accounted for awareness of potential benefits and limitations of disclosure. OBJECTIVE To determine the attitudes of cognitively normal research participants and members of the general public regarding disclosure of AD research results. DESIGN, SETTING, AND PARTICIPANTS Participants in a longitudinal aging study (Alzheimer Disease Research Center [ADRC]) were given preintervention and postintervention surveys about disclosure attitudes. In a general public sample (The American Panel Survey), participants responded to a similar survey about disclosure attitudes. INTERVENTIONS Participants in the ADRC sample were randomly assigned to a group (n = 119) that read an education intervention about the usefulness of AD biomarkers or to a placebo group (n = 100) that read as its intervention general information about the ADRC. Participants in the general public sample read a brief vignette describing participation in a longitudinal AD study. MAIN OUTCOME AND MEASURE Interest in disclosure of AD research results. RESULTS Cognitively normal ADRC participants (n = 219) were 60.7% (n = 133) female, 83.6% (n = 183) of white race, and reported a mean of 15.91 years of education. Twenty-nine individuals refused participation. The American Panel Survey participants (n = 1418) indicated they did not have AD and were 50.5% (n = 716) female, 76.7% (n = 1087) of white race, and reported a mean of 13.85 years of education. Overall, 77.6% of eligible participants (1583 of 2041) completed the survey in July 2014. Interest in disclosure was high among the ADRC participants (55.1% [119 of 216] were “extremely interested”). Viewing the education intervention predicted lower interest in disclosure (odds ratio, 2.01; 95% CI, 1.15–3.53; P = .02). High subjective risk of AD, a family

  17. Cancer research in India: national priorities, global results.

    Science.gov (United States)

    Sullivan, Richard; Badwe, Rajendra A; Rath, Goura K; Pramesh, C S; Shanta, V; Digumarti, Raghunadharao; D'Cruz, Anil; Sharma, Suresh C; Viswanath, Lokesh; Shet, Arun; Vijayakumar, Manavalan; Lewison, Grant; Chandy, Mammen; Kulkarni, Priyadarshini; Bardia, M R; Kumar, Shaleen; Sarin, Rajiv; Sebastian, Paul; Dhillon, Preet K; Rajaraman, Preetha; Trimble, Edward L; Aggarwal, Ajay; Vijaykumar, D K; Purushotham, Arnie D

    2014-05-01

    Over the past 20 years, cancer research in India has grown in size and impact. Clinicians, scientists, and government and state policy makers in India have championed cancer research, from studies to achieve low-tech, large-scale health outcomes to some of the most advanced areas of fundamental cancer science. In this paper, we frame public policy discussions about cancer with use of an in-depth analysis of research publications from India. Cancer research in India is a complex environment that needs to balance public policy across many competing agendas. We identify major needs across these environments such as those for increased research capacity and training and protected time for clinical researchers; for more support from states and enhanced collaborative funding programmes from government; for development of national infrastructures across a range of domains (ie, clinical trials, tissue banking, registries, etc); and for a streamlined and rational regulatory environment. We also discuss improvements that should be made to translate research into improvements in cancer outcomes and public health. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Normalization of research evaluation results across academic disciplines

    CERN Document Server

    Kenna, Ralph

    2010-01-01

    A conspicuous flaw in evaluation programmes such as the UK's Research Assessment Exercise is the absence of a method to compare research quality across academic disciplines. Here a systematic method is proposed to remedy this situation by normalizing across research boundaries. The approach is based upon a recently established relationship between research quality and group size which facilitates determination of discipline-dependent critical masses. For group size above the upper critical mass, this dependency of quality on quantity reduces and plateaus appear when the critical masses are large. A sensible normalization procedure is then to pitch these plateaus at similar levels. We examine the consequence of this procedure at RAE for a multitude of academic disciplines, corresponding to a range of critical masses.

  19. Translational Environmental Research: Improving the Usefulness and Usability of Research Results

    Science.gov (United States)

    Garfin, G.

    2008-12-01

    In recent years, requests for proposals more frequently emphasize outreach to stakeholder communities, decision support, and science that serves societal needs. Reports from the National Academy of Sciences and Western States Water Council emphasize the need for science translation and outreach, in order to address societal concerns with climate extremes, such as drought, the use of climate predictions, and the growing challenges of climate change. In the 1990s, the NOAA Climate Program Office developed its Regional Integrated Sciences and Asssessments program to help bridge the gap between climate science (notably, seasonal predictions) and society, to improve the flow of information to stakeholders, and to increase the relevance of climate science to inform decisions. During the same time period, the National Science Foundation initiated multi-year Science and Technology Centers and Decision Making Under Uncertainty Centers, with similar goals, but different metrics of success. Moreover, the combination of population growth, climate change, and environmental degradation has prompted numerous research initiatives on linking knowledge and action for sustainable development. This presentation reviews various models and methodologies for translating science results from field, lab, or modeling work to use by society. Lessons and approaches from cooperative extension, boundary organizations, co-production of science and policy, and medical translational research are examined. In particular, multi-step translation as practiced within the health care community is examined. For example, so- called "T1" (translation 1) research moves insights from basic science to clinical research; T2 research evaluates the effectiveness of clinical practice, who benefits from promising care regimens, and develops tools for clinicians, patients, and policy makers. T3 activities test the implementation, delivery, and spread of research results and clinical practices in order to foster

  20. ATES Smart Grids research project overview and first results

    Science.gov (United States)

    Bloemendal, Martin; Jaxa-Rozen, Marc; Rostampour, Vahab

    2016-04-01

    Background: ATES is application is growing Application of seasonal Aquifer Thermal Energy Storage (ATES) contributes to energy saving and Greenhouse Gas (GHG)-reduction goals (CBS, 2015; EU, 2010, 2014). Recently it was shown that ATES is applicable in several parts of the world (Bloemendal et al., 2015). While in most parts of the world adoption is just beginning, in the Netherlands progressive building energy efficiency regulation already caused the adoption of ATES to take off (Heekeren and Bakema, 2015; Sommer et al., 2015). As a result of the large number of ATES systems in the Netherlands, the subsurface plays a crucial role in the energy saving objectives of The Netherlands (Kamp, 2015; SER, 2013). Problem: suboptimal use of the subsurface for energy storage ATES systems accumulate in urban areas, as can be expected with a large growth of ATES systems; at many locations in Dutch cities demand for ATES transcends the available space in the subsurface (Li, 2014; Sommer et al., 2015). Within in the Dutch legal framework and state of technology optimal use of the subsurface is not secured; i.e. minimizing the total GHG emissions in a certain area. (Bloemendal et al., 2014; Li, 2014). The most important aspects in this problem are A) the permanent and often unused claim resulting from static permits and B) excessive safety zones around wells to prevent interaction. Both aspects result in an artificial reduction of subsurface space for potential new ATES systems. Recent research has shown that ground energy storage systems could be placed much closer to each other (Bakr et al., 2013; Sommer et al., 2015), and a controlled/limited degree of interaction between them can actually benefit the overall energy savings of an entire area. Solution: the approach and first results of our research project on ATES Smart Grids The heating and cooling demand of buildings is a dynamic and hard to predict process, due to effects such as weather, climate change, changing function

  1. Bibliography of clinical research in malaysia: methods and brief results.

    Science.gov (United States)

    Teng, C L; Zuhanariah, M N; Ng, C S; Goh, C C

    2014-08-01

    This article describes the methodology of this bibliography. A search was conducted on the following: (1) bibliographic databases (PubMed, Scopus, and other databases) using search terms that maximize the retrieval of Malaysian publications; (2) Individual journal search of Malaysian healthrelated journals; (3) A targeted search of Google and Google Scholar; (4) Searching of Malaysian institutional repositories; (5) Searching of Ministry of Health and Clinical Research Centre website. The publication years were limited to 2000- 2013. The citations were imported or manually entered into bibliographic software Refworks. After removing duplicates, and correcting data entry errors, PubMed's Medical Subject Headings (MeSH terms) were added. Clinical research is coded using the definition "patient-oriented-research or research conducted with human subjects (or on material of human origin) for which the investigator directly interacts with the human subjects at some point during the study." A bibliography of citations [n=2056] that fit the criteria of clinical research in Malaysia in selected topics within five domains was generated: Cancers [589], Cardiovascular diseases [432], Infections [795], Injuries [142], and Mental Health [582]. This is done by retrieving citations with the appropriate MESH terms, as follow: For cancers (Breast Neoplasms; Colorectal Neoplasms; Uterine Cervical Neoplasms), for cardiovascular diseases (Coronary Disease; Hypertension; Stroke), for infections (Dengue; Enterovirus Infections, HIV Infections; Malaria; Nipah Virus; Tuberculosis), for injuries (Accidents, Occupational; Accidents, Traffic; Child Abuse; Occupational Injuries), for mental health (Depression; Depressive Disorder; Depressive Disorder, Major; Drug Users; Psychotic Disorders; Suicide; Suicide, Attempted; Suicidal Ideation; Substance- Related Disorders).

  2. Interdisciplinary research produces results in understanding planetary dunes

    Science.gov (United States)

    Titus, Timothy N.; Hayward, Rosalyn K.; Dinwiddie, Cynthia L.

    2012-01-01

    Third International Planetary Dunes Workshop: Remote Sensing and Image Analysis of Planetary Dunes; Flagstaff, Arizona, 12–16 June 2012. This workshop, the third in a biennial series, was convened as a means of bringing together terrestrial and planetary researchers from diverse backgrounds with the goal of fostering collaborative interdisciplinary research. The small-group setting facilitated intensive discussions of many problems associated with aeolian processes on Earth, Mars, Venus, Titan, Triton, and Pluto. The workshop produced a list of key scientifc questions about planetary dune felds.

  3. INTERINSTITUTIONAL COOPERATION: RESULTS INDICATORS OF INTERACTIONS OF VISITING RESEARCHERS IN HIGHER EDUCATION AND RESEARCH INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    Fabricio Baron Mussi

    2014-12-01

    Full Text Available This paper aims to define a proposition for a characterization of indicators applicable to evaluate joint research results. In order to do that, literature on interinstitutional cooperation, exchange programs and indicators was assessed, and its guidelines, adopted. Ten cases were selected for evaluation, and the following procedures undertaken: visits to receptor institutions in several cities; visits to workplace where the subjected projects were being developed; interviews with project managers and visiting researchers; interviews with other personnel; review of the approved projects' official documentation collected during the previous steps; and a new contact with the respondents to clarify eventual doubts. Theoretically, this research contributes to the development of a proposal of a set of indicators to characterize and evaluate interdisciplinary cooperation between researchers from universities and distinct research institutes. Practical contributions to be mentioned are the information gathered that can help promotion agencies to improve their supporting edicts offered to scientific and technological development, as well as upgrading their evaluation systems regarding such actions.

  4. High school student physics research experience yields positive results

    Science.gov (United States)

    Podolak, K. R.; Walters, M. J.

    2016-03-01

    All high school students that wish to continue onto college are seeking opportunities to be competitive in the college market. They participate in extra-curricular activities which are seen to foster creativity and the skills necessary to do well in the college environment. In the case of students with an interest in physics, participating in a small scale research project while in high school gives them the hands on experience and ultimately prepares them more for the college experience. SUNY Plattsburgh’s Physics department started a five-week summer program for high school students in 2012. This program has proved not only beneficial for students while in the program, but also as they continue on in their development as scientists/engineers. Independent research, such as that offered by SUNY Plattsburgh’s five-week summer program, offers students a feel and taste of the culture of doing research, and life as a scientist. It is a short-term, risk free way to investigate whether a career in research or a particular scientific field is a good fit.

  5. Data, Problems, Heuristics and Results in Cognitive Metaphor Research

    Science.gov (United States)

    Kertesz, Andras; Rakosi, Csilla; Csatar, Peter

    2012-01-01

    Cognitive metaphor research is characterized by the diversity of rival theories. Starting from this observation, the paper focuses on the problem of how the unity and diversity of cognitive theories of metaphor can be accounted for. The first part of the paper outlines a suitable metascientific approach which emerges as a modification of B. von…

  6. Guidelines for Reporting Quantitative Methods and Results in Primary Research

    Science.gov (United States)

    Norris, John M.; Plonsky, Luke; Ross, Steven J.; Schoonen, Rob

    2015-01-01

    Adequate reporting of quantitative research about language learning involves careful consideration of the logic, rationale, and actions underlying both study designs and the ways in which data are analyzed. These guidelines, commissioned and vetted by the board of directors of "Language Learning," outline the basic expectations for…

  7. Guidelines for reporting quantitative methods and results in primary research

    NARCIS (Netherlands)

    Norris, J.M.; Plonsky, L.; Ross, S.J.; Schoonen, R.

    2015-01-01

    Adequate reporting of quantitative research about language learning involves careful consideration of the logic, rationale, and actions underlying both study designs and the ways in which data are analyzed. These guidelines, commissioned and vetted by the board of directors of Language Learning, out

  8. Some results from 50 years' research on surface forces

    Science.gov (United States)

    Derjaguin, B. V.

    1992-05-01

    A review is presented about research on surface forces and surface interactions conducted over the past half-century, with some emphasis on the pioneering contributions of the Department of Surface Phenomena at the Institute of Physical Chemistry of the USSR Academy of Sciences.

  9. Guidelines for reporting quantitative methods and results in primary research

    NARCIS (Netherlands)

    Norris, J.M.; Plonsky, L.; Ross, S.J.; Schoonen, R.

    2015-01-01

    Adequate reporting of quantitative research about language learning involves careful consideration of the logic, rationale, and actions underlying both study designs and the ways in which data are analyzed. These guidelines, commissioned and vetted by the board of directors of Language Learning,

  10. Women in Management: Leadership Theories, Research Results, and Future Directions.

    Science.gov (United States)

    Putnam, Linda L.

    This review of the literature about women in management advocates the pursuit of research on women executives as unique components in the organizational setting, with the warning that careful and unremitting attention be paid to the selection of theoretical perspectives. It examines trait and role theory, and discusses such factors as…

  11. Guidelines for Reporting Quantitative Methods and Results in Primary Research

    Science.gov (United States)

    Norris, John M.; Plonsky, Luke; Ross, Steven J.; Schoonen, Rob

    2015-01-01

    Adequate reporting of quantitative research about language learning involves careful consideration of the logic, rationale, and actions underlying both study designs and the ways in which data are analyzed. These guidelines, commissioned and vetted by the board of directors of "Language Learning," outline the basic expectations for…

  12. Mobility of Transfer Students in BC. Research Results, 2006

    Science.gov (United States)

    Box, Dale

    2007-01-01

    In the last two years, the BC Council on Admissions and Transfer (BCCAT) has conducted research on the number of potential and eligible transfer students in colleges, university colleges, and institutes in the fall of each year and the number that enrolled in a BC public university in the subsequent year with transfer as the basis of admission.…

  13. Improving the BC Transfer Experience: Feedback from Students. Research Results

    Science.gov (United States)

    British Columbia Council on Admissions and Transfer, 2012

    2012-01-01

    The BC Council on Admissions and Transfer is always seeking ways to improve the transfer system for the benefit of students. Doing so is often informed by research in one form or another. Questions were added to the 2011 Diploma, Associate Degree, and Certificate Student Outcomes (DACSO) survey to help us gain a better understanding of why some…

  14. Preliminary Results of Professional Development Program for School Science Research

    Science.gov (United States)

    Wuttiprom, Sura; Wuttisela, Karntarat; Phonchaiya, Sonthi; Athiwaspong, Wanwalai; Chitaree, Ratchapak; Sharma, Manjula Devi

    2016-01-01

    Teachers need to design their courses to be as similar to real-life situations as possible as genuine learning emerges in real life as opposed to studying in class. Research-based learning is an innovative approach exploring many critical strategies for success in the twenty-first century. In it, students drive their own learning through inquiry,…

  15. Peer-Reviewed Open Research Data: Results of a Pilot

    Directory of Open Access Journals (Sweden)

    Marjan Grootveld

    2012-12-01

    Full Text Available Peer review of publications is at the core of science and primarily seen as instrument for ensuring research quality. However, it is less common to independently value the quality of the underlying data as well. In the light of the ‘data deluge’ it makes sense to extend peer review to the data itself and this way evaluate the degree to which the data are fit for re-use. This paper describes a pilot study at EASY - the electronic archive for (open research data at our institution. In EASY, researchers can archive their data and add metadata themselves. Devoted to open access and data sharing, at the archive we are interested in further enriching these metadata with peer reviews.As a pilot, we established a workflow where researchers who have downloaded data sets from the archive were asked to review the downloaded data set. This paper describes the details of the pilot including the findings, both quantitative and qualitative. Finally, we discuss issues that need to be solved when such a pilot is turned into a structural peer review functionality for the archiving system.

  16. Thin-film voltammetry and its analytical applications: a review.

    Science.gov (United States)

    Tian, Huihui; Li, Yunchao; Shao, Huibo; Yu, Hua-Zhong

    2015-01-15

    Electrochemical reactions at the interfaces of immiscible electrolyte solutions (ITIES) are of fundamental importance in the fields of chemical, biological and pharmaceutical sciences. Four-electrode cell setup, scanning electrochemical microscopy (SECM) and thin-film voltammetry are the three most frequently used methods for studying the electrochemical processes at these interfaces. The principle, experimental design, advantages and challenges of the three methods are described and compared. The thin-film voltammetry is highlighted for its simplicity in experimental operation and kinetic data analysis. Its versatile analytical applications are discussed in detail, including the study of redox properties of hydrophobic compounds, evaluation of interfacial electron transfer kinetics, synthesis of nanoparticles/nanostructures, and illustration of cross-membrane ion transport phenomena.

  17. Differential Pulse Anodic Stripping Voltammetry for Mercury Determination

    OpenAIRE

    2015-01-01

    In the present work voltammetric investigations have been performed on HgCl2 aqueous solutions prepared from a Cz 9024 reagent. Carbon paste electrode (CPE), eriochrome black T modified carbon paste electrode (MCPE/EBT) and KCl 1M as background electrolyte, were involved within the experimental procedures. Cyclic voltammetry (CV) has been performed in order to compare the behaviour of the two electrodes in both K3[Fe(CN)6] and mercury calibration aqueous solution. Differential pulse anodic st...

  18. Surface Catalytic Mechanism in Square-Wave Voltammetry

    OpenAIRE

    Mirceski, Valentin; Gulaboski, Rubin

    2001-01-01

    A pseudo-first-order catalytic mechanism in which both reactant and product of the redox reaction are strongly immobilized on the electrode surface is theoretically analyzed under conditions of square-wave voltammetry (SWV). A mathematical procedure is developed for diffusionless conditions. The relationships between the properties of the voltammetric response and both the kinetic parameters of the redox reaction and the parameters of the excitement signal are studied. The phenomenon...

  19. (Industrial Research on Building Production: results and future developments

    Directory of Open Access Journals (Sweden)

    Giuseppe Alaimo

    2013-10-01

    Full Text Available In accordance with the most recent management mandate, ISTeA (Italian Society of Science, Technology and engineering of Architecture has devoted its efforts to outlining those topics which are of fundamental importance for the activity of its stakeholders, in line with the road maps of national and Community funding programmes and with the strategic objectives of (Industrial Research which range from the energy-environmental performance of buildings and districts to automation in construction within the context of Smart Cities and Social Innovation. These research programmes need to be planned and negotiated with industrial stakeholders and carried out in partnership with them. This explains why the 2011 ISTeA Conference produced a number of position papers, the 2012 Conference traced the state of the art in the topics identified and the 2013 Conferencedeals with the non-instrumental relationship between Building Production and ICT.

  20. Interdisciplinary Research Produces Results in the Understanding of Planetary Dunes

    Science.gov (United States)

    Titus, Timothy N.; Hayward, Rosalyn Kay; Bourke, Mary C.

    2010-08-01

    Second International Planetary Dunes Workshop: Planetary Analogs—Integrating Models, Remote Sensing, and Field Data; Alamosa, Colorado, 18-21 May 2010; Dunes and other eolian bed forms are prominent on several planetary bodies in our solar system. Despite 4 decades of study, many questions remain regarding the composition, age, and origins of these features, as well as the climatic conditions under which they formed. Recently acquired data from orbiters and rovers, together with terrestrial analogs and numerical models, are providing new insights into Martian sand dunes, as well as eolian bed forms on other terrestrial planetary bodies (e.g., Titan). As a means of bringing together terrestrial and planetary researchers from diverse backgrounds with the goal of fostering collaborative interdisciplinary research, the U.S. Geological Survey (USGS), the Carl Sagan Center for the Study of Life in the Universe, the Desert Research Institute, and the U.S. National Park Service held a workshop in Colorado. The small group setting facilitated intensive discussion of problems and issues associated with eolian processes on Earth, Mars, and Titan.

  1. Solution voltammetry of 4 nm magnetite iron oxide nanoparticles.

    Science.gov (United States)

    Roberts, Joseph J P; Westgard, John A; Cooper, Laura M; Murray, Royce W

    2014-07-30

    The voltammetry of solution-dispersed magnetite iron oxide Fe3O4 nanoparticles is described. Their currents are controlled by nanoparticle transport rates, as shown with potential step chronoamperometry and rotated disk voltammetry. In pH 2 citrate buffer with added NaClO4 electrolyte, solution cyclic voltammetry of these nanoparticles (average diameter 4.4 ± 0.9 nm, each containing ca. 30 Fe sites) displays an electrochemically irreversible oxidation with E(PEAK) at ca. +0.52 V and an irreversible reduction with E(PEAK) at ca. +0.2 V vs Ag/AgCl reference electrode. These processes are presumed to correspond to the formal potentials for one-electron oxidation of Fe(II) and reduction of Fe(III) at their different sites in the magnetite nanoparticle structure. The heterogeneous electrode reaction rates of the nanoparticles are very slow, in the 10(-5) cm/s range. The nanoparticles are additionally characterized by a variety of tools, e.g., TEM, UV/vis, and XPS spectroscopies.

  2. African Primary Care Research: qualitative data analysis and writing results.

    Science.gov (United States)

    Mabuza, Langalibalele H; Govender, Indiran; Ogunbanjo, Gboyega A; Mash, Bob

    2014-06-05

    This article is part of a series on African primary care research and gives practical guidance on qualitative data analysis and the presentation of qualitative findings. After an overview of qualitative methods and analytical approaches, the article focuses particularly on content analysis, using the framework method as an example. The steps of familiarisation, creating a thematic index, indexing, charting, interpretation and confirmation are described. Key concepts with regard to establishing the quality and trustworthiness of data analysis are described. Finally, an approach to the presentation of qualitative findings is given.

  3. AiResearch QCGAT engine: Acoustic test results

    Science.gov (United States)

    Kisner, L. S.

    1980-01-01

    The noise levels of the quiet, general aviation turbofan (QCGAT) engine were measured in ground static noise tests. The static noise levels were found to be markedly lower than the demonstrably quiet AiResearch model TFE731 engine. The measured QCGAT noise levels were correlated with analytical noise source predictions to derive free-field component noise predictions. These component noise sources were used to predict the QCGAT flyover noise levels at FAR Part 36 conditions. The predicted flyover noise levels are about 10 decibels lower than the current quietest business jets.

  4. Ireland's deep-water coral carbonate mounds: multidisciplinary research results

    Science.gov (United States)

    Kozachenko, M.; Wheeler, A.; Beyer, A.; Blamart, D.; Masson, D.; Olu-Le Roy, K.

    2003-04-01

    Recent international research activity, involving a strong Irish collaboration, has shown that coral reefs are not exclusively associated with warm tropical waters but are also present in the deeper and colder Northeast Atlantic. In the Porcupine Seabight west of Ireland, coral-colonised carbonate mounds (up to 350m high) are present at 600-900m water depth. The corals Lophelia pertusa L. and Madrepora oculata L. contribute to this diverse ecosystem that may also play a significant role in expanding deep-water fisheries. New side-scan sonar, multibeam echosounder, sub-bottom profiler and underwater video imagery supplemented with sedimentological sample material were used to map the seabed in the environs of the Belgica Carbonate Mound province, eastern Porcupine Seabight. The data were integrated in a GIS and provides information on sediment pathways and benthic current patterns within the study area. A facies map of the study area highlights differing sedimentary processes showing evidences for strong northward bottom currents whose interaction has an influence on mounds growth and morphology. This survey revealed mound flanks dominated by sediment waves that give way to coral banks towards the mound summits. A form of coral accumulation was also documented. Detailed analyses of sediment properties from long cores through sediment drifts have generated a high-resolution palaeoclimate record revealing temporal patterns in bottom current strength variations. An accurate assessment of this influence on mound through a comparison with coral growth rates is ongoing.

  5. Guidelines for Initiating a Research Agenda: Research Design and Dissemination of Results.

    Science.gov (United States)

    Delost, Maria E; Nadder, Teresa S

    2014-01-01

    Successful research outcomes require selection and implementation of the appropriate research design. A realistic sampling plan appropriate for the design is essential. Qualitative or quantitative methodology may be utilized, depending on the research question and goals. Quantitative research may be experimental where there is an intervention, or nonexperimental, if no intervention is included in the design. Causation can only be established with experimental research. Popular types of nonexperimental research include descriptive and survey research. Research findings may be disseminated via presentations, posters, and publications, such as abstracts and manuscripts.

  6. Geodetic Volcano Monitoring Research in Canary Islands: Recent Results

    Science.gov (United States)

    Fernandez, J.; Gonzalez, P. J.; Arjona, A.; Camacho, A. G.; Prieto, J. F.; Seco, A.; Tizzani, P.; Manzo, M. R.; Lanari, R.; Blanco, P.; Mallorqui, J. J.

    2009-05-01

    The Canarian Archipelago is an oceanic island volcanic chain with a long-standing history of volcanic activity (> 40 Ma). It is located off the NW coast of the African continent, lying over a transitional crust of the Atlantic African passive margin. At least 12 eruptions have been occurred on the islands of Lanzarote, Tenerife and La Palma in the last 500 years. Volcanism manifest predominantly as basaltic strombolian monogenetic activity (whole archipelago) and central felsic volcanism (active only in Tenerife Island). We concentrate our studies in the two most active islands, Tenerife and La Palma. In these islands, we tested different methodologies of geodetic monitoring systems. We use a combination of ground- and space-based techniques. At Tenerife Island, a differential interferometric study was performed to detect areas of deformation. DInSAR detected two clear areas of deformation, using this results a survey-based GPS network was designed and optimized to control those deformations and the rest of the island. Finally, using SBAS DInSAR results weak spatial long- wavelength subsidence signals has been detected. At La Palma, the first DInSAR analysis have not shown any clear deformation, so a first time series analysis was performed detecting a clear subsidence signal at Teneguia volcano, as for Tenerife a GPS network was designed and optimized taking into account stable and deforming areas. After several years of activities, geodetic results served to study ground deformations caused by a wide variety of sources, such as changes in groundwater levels, volcanic activity, volcano-tectonics, gravitational loading, etc. These results proof that a combination of ground-based and space-based techniques is suitable tool for geodetic volcano monitoring in Canary Islands. Finally, we would like to strength that those results could have serious implications on the continuous geodetic monitoring system design and implementation for the Canary Islands which is under

  7. Hydrodynamic sono-voltammetry of ferrocene in [Tf2N]- based ionic liquid media.

    Science.gov (United States)

    Costa, Cédric; Doche, Marie-Laure; Hihn, Jean-Yves; Bisel, Isabelle; Moisy, Philippe; Lévêque, Jean-Marc

    2010-02-01

    The present work deals with the hydrodynamic behavior of several room-temperature ionic liquids presenting the same bis(trifluoromethanesulfonyles)imide anion, associated with four different cations: 1-butyl-3-methylimidazolium, 1-octyl-3-methylimidazolium, N-trimethyl-N-propylammonium and 1-butyl-1-methylpyrrolidinium cations. Steady state voltammetry was used as an electrochemical technique to characterize mass transfer in both silent and sonicated conditions, using a rotating disk electrode. Results obtained in RTILs media are compared to those acquired in synthetic solutions of controlled viscosity, in order to develop a better understanding of the phenomena involved in such media.

  8. Electrodeposition of Iridium Oxide by Cyclic Voltammetry: Application of Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Kakooei Saeid

    2014-07-01

    Full Text Available The effects of scan rate, temperature, and number of cycles on the coating thickness of IrOX electrodeposited on a stainless steel substrate by cyclic voltammetry were investigated in a statistical system. The central composite design, combined with response surface methodology, was used to study condition of electrodeposition. All fabricated electrodes were characterized using electrochemical methods. Field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy were performed for IrOX film characterization. Results showed that scan rate significantly affects the thickness of the electrodeposited layer. Also, the number of cycles has a greater effect than temperature on the IrOX thickness.

  9. SPR imaging combined with cyclic voltammetry for the detection of neural activity

    Directory of Open Access Journals (Sweden)

    Hui Li

    2014-03-01

    Full Text Available Surface plasmon resonance (SPR detects changes in refractive index at a metal-dielectric interface. In this study, SPR imaging (SPRi combined with cyclic voltammetry (CV was applied to detect neural activity in isolated bullfrog sciatic nerves. The neural activities induced by chemical and electrical stimulation led to an SPR response, and the activities were recorded in real time. The activities of different parts of the sciatic nerve were recorded and compared. The results demonstrated that SPR imaging combined with CV is a powerful tool for the investigation of neural activity.

  10. Detection of iron(III)-binding ligands originating from marine phytoplankton using cathodic stripping voltammetry.

    Science.gov (United States)

    Hasegawa, Hiroshi; Maki, Teruya; Asano, Kohnosuke; Ueda, Kentaro; Ueda, Kazumasa

    2004-01-01

    The sample preparation and analytical methodology are described for detecting biologically produced iron(III)-binding ligands in laboratory cultures of coastal marine phytoplankton. The iron(III)-binding ligands from the culture media were purified by passage through a column packing with a hydrophobic absorbent. The concentrations and stability constants of the ligands were determined by adsorptive cathodic stripping voltammetry with competitive ligand equilibration. The analytical results of the cultivated cultures suggest that eukaryotic phytoplankton would produce iron(III)-binding ligands in analogy with other microorganisms.

  11. Synthesis on research results of FGD gypsum briquetting

    Directory of Open Access Journals (Sweden)

    Kosturkiewicz Bogdan

    2017-01-01

    Full Text Available FGD gypsum products can be characterized by significant solubility in water and dusting in dry state. These characteristics can cause a considerable pollution of air, water and soil. Among many approaches of preparing utilization of this waste, the process of compaction using briquetting has proved to be very effective. Using FGD gypsum products a new material of fertilizers characteristics has been acquired and this material is resistant to the conditions of transportation. This paper presents results of experimental briquetting of flue gas desulphurisation products in a roll press. The experiments were conducted in a laboratory roll presses LPW 450 and LPW 1100 equipped with two interchangeable forming rings that form material into saddle-shaped briquettes with volume 6,5 cm3 and 85 cm3. The experiments were conducted with various percentage amounts of FGD gypsum moisture. The results provided information regarding influence of moisture and roll press configuration on quality of briquettes. On the basis of obtained results, technological process and a general outline of technological line for FGD gypsum were developed. Two roll presses of own construction with different outputs were identified as appropriate for this purpose. A range of necessary works related to their adaptation for the FGD gypsum briquetting were pointed out.

  12. Oxidation management of white wines using cyclic voltammetry and multivariate process monitoring.

    Science.gov (United States)

    Martins, Rui C; Oliveira, Raquel; Bento, Fatima; Geraldo, Dulce; Lopes, Vitor V; Guedes de Pinho, Paula; Oliveira, Carla M; Silva Ferreira, Antonio C

    2008-12-24

    The development of a fingerprinting strategy capable to evaluate the "oxidation status" of white wines based on cyclic voltammetry is proposed here. It is known that the levels of specific antioxidants and redox mechanisms may be evaluated by cyclic voltammetry. This electrochemical technique was applied on two sets of samples. One group was composed of normal aged white wines and a second group obtained from a white wine forced aging protocol with different oxygen, SO(2), pH, and temperature regimens. A study of antioxidant additions, namely ascorbic acid, was also made in order to establish a statistical link between voltammogram fingerprints and chemical antioxidant substances. It was observed that the oxidation curve presented typical features, which enables sample discrimination according to age, oxygen consumption, and antioxidant additions. In fact, it was possible to place the results into four significant orthogonal directions, compressing 99.8% of nonrandom features. Attempts were made to make voltammogram fingerprinting a tool for monitoring oxidation management. For this purpose, a supervised multivariate control chart was developed using a control sample as reference. When white wines are plotted onto the chart, it is possible to monitor the oxidation status and to diagnose the effects of oxygen regimes and antioxidant activity. Finally, quantification of substances implicated in the oxidation process as reagents (antioxidants) and products (off-flavors) was tried using a supervised algorithmic the partial least square regression analysis. Good correlations (r > 0.93) were observed for ascorbic acid, Folin-Ciocalteu index, total SO(2), methional, and phenylacetaldehyde. These results show that cyclic voltammetry fingerprinting can be used to monitor and diagnose the effects of wine oxidation.

  13. Results of pollution research and tests at CPRI, Hyderabad

    Energy Technology Data Exchange (ETDEWEB)

    Nirgude, P.M.; Devendranath, D.; Chandrakanth, N.S.; Shivakumara Aradhya, R.S.; Channakeshava [Central Power Research Inst., Bangalore (India)

    1997-12-31

    The design of electrical insulation from the point of view of pollution performance was discussed. A pollution laboratory was established at Hyderabad, India, to perform tests on insulators under polluted conditions in the EHV and UHV range. These tests determined the insulation strength of different types of insulators under polluted conditions. Studies have been conducted on the pollution performance of line and post insulators under AC voltages using the salt fog method. The following insulator parameters that affect pollution performance were examined: creepage length, diameter, shape and string length. Results showed an increase in leakage current with specific creepage length. 9 refs., 1 tab., 5 figs.

  14. Structural dialectical approach in psychology: problems and research results

    Directory of Open Access Journals (Sweden)

    Veraksa, Nikolay E.

    2013-06-01

    Full Text Available In this article dialectical thinking is regarded as one of the central cognitive processes. Because of this cognitive function we can analyze the development of processes and objects. It also determines the possibilities for the creative transformation of some content and for solving problems. The article presents a description and the results of experimental studies. This evidence proves that dialectical thinking is a specific line of cognitive development in children and adults. This line can degrade during school time if the educational program follows formal logical principles, or it can become significantly stronger if the pedagogy is based on dialectical methodology.

  15. Medieval horse stable; the results of multi proxy interdisciplinary research.

    Directory of Open Access Journals (Sweden)

    Miroslav Dejmal

    Full Text Available A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle.

  16. Medieval horse stable; the results of multi proxy interdisciplinary research.

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle.

  17. Medieval Horse Stable; The Results of Multi Proxy Interdisciplinary Research

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle. PMID:24670874

  18. Glyphosate detection with ammonium nitrate and humic acids as potential interfering substances by pulsed voltammetry technique.

    Science.gov (United States)

    Martínez Gil, Pablo; Laguarda-Miro, Nicolas; Camino, Juan Soto; Peris, Rafael Masot

    2013-10-15

    Pulsed voltammetry has been used to detect and quantify glyphosate on buffered water in presence of ammonium nitrate and humic substances. Glyphosate is the most widely used herbicide active ingredient in the world. It is a non-selective broad spectrum herbicide but some of its health and environmental effects are still being discussed. Nowadays, glyphosate pollution in water is being monitored but quantification techniques are slow and expensive. Glyphosate wastes are often detected in countryside water bodies where organic substances and fertilizers (commonly based on ammonium nitrate) may also be present. Glyphosate also forms complexes with humic acids so these compounds have also been taken into consideration. The objective of this research is to study the interference of these common pollutants in glyphosate measurements by pulsed voltammetry. The statistical treatment of the voltammetric data obtained lets us discriminate glyphosate from the other studied compounds and a mathematical model has been built to quantify glyphosate concentrations in a buffer despite the presence of humic substances and ammonium nitrate. In this model, the coefficient of determination (R(2)) is 0.977 and the RMSEP value is 2.96 × 10(-5) so the model is considered statistically valid.

  19. In situ generation and detection of methyl radical by voltammetry

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In persulfate-acetate, dimethyl sulfoxide or tert-butyl alcohol systems, in situ generation and detection of methyl free radical are realized with voltammetry. It includes the following successive processes. The persulfate S2O82- is polarographically reduced via one-electron addition to sulfate radical SO4-., the SO4-. Initiates chain reaction with acetate, dimethyl sulfoxide, or tert-butyl alcohol on the electrode surface to produce a methyl radical, and one-electron reduction of the methyl radical yields its polarographic reduction wave. In comparison with the known techniques such as ultraviolet radiolysis coupling with electron spin resonance, etc., the proposed method is simple, sensitive and selective.

  20. Characterization of an electrochemical mercury sensor using alternating current, cyclic, square wave and differential pulse voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Guerreiro, Gabriela V.; Zaitouna, Anita J.; Lai, Rebecca Y., E-mail: rlai2@unl.edu

    2014-01-31

    Graphical abstract: -- Highlights: •An electrochemical Hg(II) sensor based on T–Hg(II)–T sensing motif was fabricated. •A methylene blue-modified DNA probe was used to fabricate the sensor. •Sensor performance was evaluated using ACV, CV, SWV, and DPV. •The sensor behaves as a “signal-off” sensor in ACV and CV. •The sensor behaves as either a “signal-on” or “signal-off” sensor in SWV and DPV. -- Abstract: Here we report the characterization of an electrochemical mercury (Hg{sup 2+}) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a “signal-off” sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a “signal-off” or “signal-on” sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed “signal-on” behavior at low frequencies and “signal-off” behavior at high frequencies. In DPV, the sensor showed “signal-off” behavior at short pulse widths and “signal-on” behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10 nM, with a linear dynamic range between 10 nM and 500 nM. In addition, the sensor responded to Hg{sup 2+} rather rapidly; majority of the signal change occurred in <20 min. Overall, the sensor retains all the characteristics of this class of sensors; it is reagentless, reusable, sensitive, specific and selective. This study also highlights the feasibility of using a MB-modified probe for real-time sensing of Hg{sup 2+}, which has not been previously reported. More importantly, the observed “switching” behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors.

  1. Use of results of public health research in a governmental institution of Colombia

    Directory of Open Access Journals (Sweden)

    Janeth Mosquera

    2005-03-01

    Full Text Available Background: Research is an essential function of public health. Great amounts of resources are spent in health research that should contribute to improve people’s health. However, impact or social gains of health research have been insufficiently measured. Objectives: To explore perceptions of policy-makers and researchers about research use in public health and to identify barriers and facilitators for using research results at a Departmental Secretariat of Health, in Colombia. Methods: We carried out a case-study about perceptions of use of research results in the Valle del Cauca Secretariat of Health using a semi-structured interview with 17 health policy makers and researchers. Researchers in health research institutions and health officials in the Secretariat of Health were selected by purposing sample. We identified preliminary and emergent categories; relations between them and suggested explanations of the issues under study were established. Main results: Policy makers to guide decisions in public health at the Departmental Secretariat of Health do not use research results. Barriers for using research results are associated with the lack of a research policy, deficiencies in research management structure and exclusive contractual relationships established between researchers and policy-makers. There are few experiences in using research results and they were facilitated by a better knowledge of health officials about research process, a participative role of them in research, and by characteristics of research development. Conclusions: Research results do not contribute to make decisions at the Secretariat of Health.

  2. Strategies for low detection limit measurements with cyclic voltammetry.

    Science.gov (United States)

    Wiedemann, D J; Kawagoe, K T; Kennedy, R T; Ciolkowski, E L; Wightman, R M

    1991-12-15

    Cyclic voltammetry of Nafion-coated, carbon-fiber electrodes is used to detect trace concentrations of dopamine, both in a flow injection apparatus and in the brain of an anaesthetized rat. To improve signal-to-noise ratios, the sources of noise during cyclic voltammetry have been determined and strategies have been developed to decrease the noise. With the potentiostat employed, the measured noise is comparable to that expected for Johnson noise from the feedback resistor of the current transducer. Additional noise arises from the waveform generator employed and, in some cases, line noise. Line noise is discriminated against by starting each cyclic voltammogram either in phase or 180 degrees out of phase with the line frequency. When used in vivo, additional noise also arises from the physiological activity of the animal. Detection limits are found to closely correspond to those predicted on the basis of simulation of the voltammetric shape and the measured noise. Detection limits are improved by the use of appropriate analog and digital filtering, ensemble averaging, and appropriate timing of repetitive cyclic voltammograms. The combined use of these techniques enables the in vivo detection of approximately 100 nM of dopamine with a signal-to-noise ratio of 25.

  3. Differential Pulse Anodic Stripping Voltammetry for Mercury Determination

    Directory of Open Access Journals (Sweden)

    Vereștiuc Paul C.

    2015-07-01

    Full Text Available In the present work voltammetric investigations have been performed on HgCl2 aqueous solutions prepared from a Cz 9024 reagent. Carbon paste electrode (CPE, eriochrome black T modified carbon paste electrode (MCPE/EBT and KCl 1M as background electrolyte, were involved within the experimental procedures. Cyclic voltammetry (CV has been performed in order to compare the behaviour of the two electrodes in both K3[Fe(CN6] and mercury calibration aqueous solution. Differential pulse anodic stripping voltammetry (DPASV was used to determine the most suitable parameters for mercury determination. All experiments were performed at 25 ± 1 ℃, using an electrochemical cell with three-electrodes connected to an Autolab PG STAT 302N (Metrohm-Autolab potentiostat that is equipped with Nova 1.11 software. The measured potential values were generated by using the silver chloride electrode (AgClE as reference and a platinum wire electrode as auxiliary. A series of time depending equations for the pre-concentration and concentration steps were established, with the observation that a higher sensitivity can be obtained while increasing the pre-concentration time. DPASV were drawn using the CPE in 11.16 % coriander, as mercury complex, the voltamograms signals indicating mercury oxidation, with signal intensity increasing in time.

  4. Thin film voltammetry of metabolic enzymes in rat liver microsomes

    Science.gov (United States)

    Krishnan, Sadagopan; Rusling, James F.

    2007-01-01

    We report herein thin film voltammetry and kinetics of electron transfer for redox proteins in rat liver microsomes for the first time. Films were made layer-by-layer from liver microsomes and polycations on pyrolytic graphite electrodes. Cyclic voltammograms were chemically reversible with a midpoint potential of −0.48 V vs SCE at 0.1 V s−1 in pH 7.0 phosphate buffer. Reduction peak potentials shifted negative at higher scan rates, and oxidation-reduction peak current ratios were ∼1 consistent with non-ideal quasireversible thin film voltammetry. Analysis of oxidation-reduction peak separations gave an average apparent surface electron transfer rate constant of 30 s−1. Absence of significant electrocatalytic reduction of O2 or H2O2 and lack of shift in midpoint potential when CO is added that indicates lack of an iron heme cofactor suggest that peaks can be attributed to oxidoreductases present in the microsomes rather than cytochrome P450 enzymes. PMID:18037986

  5. Voltage biasing, cyclic voltammetry, & electrical impedance spectroscopy for neural interfaces.

    Science.gov (United States)

    Wilks, Seth J; Richner, Tom J; Brodnick, Sarah K; Kipke, Daryl R; Williams, Justin C; Otto, Kevin J

    2012-02-24

    Electrical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measure properties of the electrode-tissue interface without additional invasive procedures, and can be used to monitor electrode performance over the long term. EIS measures electrical impedance at multiple frequencies, and increases in impedance indicate increased glial scar formation around the device, while cyclic voltammetry measures the charge carrying capacity of the electrode, and indicates how charge is transferred at different voltage levels. As implanted electrodes age, EIS and CV data change, and electrode sites that previously recorded spiking neurons often exhibit significantly lower efficacy for neural recording. The application of a brief voltage pulse to implanted electrode arrays, known as rejuvenation, can bring back spiking activity on otherwise silent electrode sites for a period of time. Rejuvenation alters EIS and CV, and can be monitored by these complementary methods. Typically, EIS is measured daily as an indication of the tissue response at the electrode site. If spikes are absent in a channel that previously had spikes, then CV is used to determine the charge carrying capacity of the electrode site, and rejuvenation can be applied to improve the interface efficacy. CV and EIS are then repeated to check the changes at the electrode-tissue interface, and neural recordings are collected. The overall goal of rejuvenation is to extend the functional lifetime of implanted arrays.

  6. Arsenic speciation in natural waters by cathodic stripping voltammetry.

    Science.gov (United States)

    Gibbon-Walsh, Kristoff; Salaün, Pascal; van den Berg, Constant M G

    2010-03-03

    Contamination of groundwater with arsenic (As) is a major health risk through contamination of drinking and irrigation water supplies. In geochemically reducing conditions As is mostly present as As(III), its most toxic species. Various methods exist to determine As in water but these are not suitable for monitoring arsenic speciation at its original pH and without preparation. We present a method that uses cathodic stripping voltammetry (CSV) to determine reactive As(III) at a vibrating, gold, microwire electrode. The As(III) is detected after adsorptive deposition of As(OH)(3)(0), followed by a potential scan to measure the reduction current from As(III) to As(0). The method is suitable for waters of pH 7-12, has an analytical range of 1 nM to 100 microM As (0.07-7500 ppb) and a limit of detection of 0.5 nM with a 60 s deposition time. The As speciation protocol involves measuring reactive As(III) by CSV at the original pH and acidification to pH 1 to determine inorganic As(III)+As(V) by anodic stripping voltammetry (ASV) using the same electrode. Total dissolved As is determined by ASV after UV-digestion at pH 1. The method was successfully tested on various raw groundwater samples from boreholes in the UK and West Bengal. Copyright 2010 Elsevier B.V. All rights reserved.

  7. DIFFERENTIAL PULSE ANODIC STRIPPING VOLTAMMETRY FOR DETERMINATION OF SOME HEAVY METALS IN URANIUM

    Directory of Open Access Journals (Sweden)

    Saryati Saryati

    2010-06-01

    Full Text Available The direct determination of some metals impurity in uranium by using differential pulse anodic stripping voltammetry (DPASV method at a hanging mercury drop electrode and in a carbonate buffer media was developed. It was found that the carbonate buffer show the strongest affinity for uranium and gives the best separation between the DPASV peaks of heavy metals impurities. The carbonate concentration markedly affects the oxidation and reduction the major and the minor constituents of the uranium samples. In 0.1 M carbonate buffer solution pH 10, copper, bismuth, thalium, lead, cadmium, zinc, could be determined without the removal of the uranium matrix. Recovery and relative standard deviation (RSD of this method was in the range of 174% - 85.2% for recovery and 36.8% - 1.2% for RSD. The larger error of analytical result was obtained for Zn at low concentration. In general, the analytic results error and RSD decreased with increasing metals concentration.   Keywords: heavy metal determination, differential pulse anodic stripping voltammetry, uranium

  8. Comparison of the stem-loop and linear probe-based electrochemical DNA sensors by alternating current voltammetry and cyclic voltammetry.

    Science.gov (United States)

    Yang, Weiwei; Lai, Rebecca Y

    2011-12-06

    Here we systematically characterized the sensor performance of the stem-loop probe (SLP) and linear probe (LP) electrochemical DNA sensors using alternating current voltammetry (ACV) and cyclic voltammetry (CV), with the goal of generating the set of operational criteria that best suits each sensor architecture, in addition to elucidating the signaling mechanism behind these sensors. Although the LP sensor shows slightly better % signal suppression (SS) upon hybridization with the perfect match target at 10 Hz, our frequency-dependent study suggests that it shows optimal % SS only in a very limited AC frequency range. Similar results are observed in CV studies in which the LP sensor, when compared to the SLP sensor, displays a narrower range of voltammetric scan rates where the optimal % SS can be achieved. More importantly, the difference between the two sensors' performance is particularly pronounced if the change in integrated charge (Q) upon target hybridization, rather than the peak current (I), is measured in CV. The temperature-dependent study further highlights the differences between the two sensors, where the LP sensor, owing to the flexible linear probe architecture, is more readily perturbed by temperature changes. Both SLP and LP sensors, however, show a loss of % SS when operated at elevated temperatures, despite the significant improvement in the hybridization kinetics. In conjunction with the ACV, CV, and temperature-dependent studies, the electron-transfer kinetics study provides further evidence in support of the proposed signaling mechanism of these two sensors, in which the SLP sensor's signaling efficiency and sensor performance is directly linked to the hybridization-induced conformational change in the redox-labeled probe, whereas the performance of the LP sensor relies on the hybridization-induced change in probe dynamics. © 2011 American Chemical Society

  9. Determination of genotoxic effects of methidathion alkaline hydrolysis in human lymphocytes using the micronucleus assay and square-wave voltammetry.

    Science.gov (United States)

    Stivaktakis, Polychronis D; Giannakopoulos, Evangelos; Vlastos, Dimitris; Matthopoulos, Demetrios P

    2017-02-01

    The interaction of pesticides with environmental factors, such as pH, may result in alterations of their physicochemical properties and should be taken into consideration in regard to their classification. This study investigates the genotoxicity of methidathion and its alkaline hydrolysis by-products in cultured human lymphocytes, using the square-wave voltammetry (square wave-adsorptive cathodic stripping voltammetry (SW-AdCSV) technique) and the cytokinesis block micronucleus assay (CBMN assay). According to the SW-AdCSV data the alkaline hydrolysis of methidathion results in two new molecules, one non-electro-active and a second electro-active which is more genotoxic than methidathion itself in cultured human lymphocytes, inducing higher micronuclei frequencies. The present study confirms the SW-AdCSV technique as a voltammetric method which can successfully simulates the electrodynamics of the cellular membrane.

  10. Hydrodynamic Voltammetry as a Rapid and Simple Method for Evaluating Soil Enzyme Activities

    Directory of Open Access Journals (Sweden)

    Kazuto Sazawa

    2015-03-01

    Full Text Available Soil enzymes play essential roles in catalyzing reactions necessary for nutrient cycling in the biosphere. They are also sensitive indicators of ecosystem stress, therefore their evaluation is very important in assessing soil health and quality. The standard soil enzyme assay method based on spectroscopic detection is a complicated operation that requires the removal of soil particles. The purpose of this study was to develop a new soil enzyme assay based on hydrodynamic electrochemical detection using a rotating disk electrode in a microliter droplet. The activities of enzymes were determined by measuring the electrochemical oxidation of p-aminophenol (PAP, following the enzymatic conversion of substrate-conjugated PAP. The calibration curves of β-galactosidase (β-gal, β-glucosidase (β-glu and acid phosphatase (AcP showed good linear correlation after being spiked in soils using chronoamperometry. We also performed electrochemical detection using real soils. Hydrodynamic chronoamperometry can be used to assess the AcP in soils, with a detection time of only 90 s. Linear sweep voltammetry was used to measure the amount of PAP released from β-gal and β-glu by enzymatic reaction after 60 min. For the assessment of soil enzymes, the results of hydrodynamic voltammetry assay compared favorably to those using a standard assay procedure, but this new procedure is more user-friendly, rapid and simple.

  11. Combined characterization of bovine polyhemoglobin microcapsules by UV-Vis absorption spectroscopy and cyclic voltammetry.

    Science.gov (United States)

    Knirsch, Marcos Camargo; Dell'Anno, Filippo; Salerno, Marco; Larosa, Claudio; Polakiewicz, Bronislaw; Eggenhöffner, Roberto; Converti, Attilio

    2017-03-01

    Polyhemoglobin produced from pure bovine hemoglobin by reaction with PEG bis(N-succynimidil succinate) as a cross-linking agent was encapsulated in gelatin and dehydrated by freeze-drying. Free carboxyhemoglobin and polyhemoglobin microcapsules were characterized by UV-Vis spectroscopy in the absorption range 450-650 nm and cyclic voltammetry in the voltage range from -0.8 to 0.6 mV to evaluate the ability to break the bond with carbon monoxide and to study the carrier's affinity for oxygen, respectively. SEM used to observe the shape of cross-linked gelatin-polyhemoglobin microparticles showed a regular distribution of globular shapes, with mean size of ~750 nm, which was ascribed to gelatin. Atomic absorption spectroscopy was also performed to detect iron presence in microparticles. Cyclic voltammetry using an Ag-AgCl electrode highlighted characteristic peaks at around -0.6 mV that were attributed to reversible oxygen bonding with iron in oxy-polyhemoglobin structure. These results suggest this technique as a powerful, direct and alternative method to evaluate the extent of hemoglobin oxygenation.

  12. Hydrodynamic voltammetry as a rapid and simple method for evaluating soil enzyme activities.

    Science.gov (United States)

    Sazawa, Kazuto; Kuramitz, Hideki

    2015-03-04

    Soil enzymes play essential roles in catalyzing reactions necessary for nutrient cycling in the biosphere. They are also sensitive indicators of ecosystem stress, therefore their evaluation is very important in assessing soil health and quality. The standard soil enzyme assay method based on spectroscopic detection is a complicated operation that requires the removal of soil particles. The purpose of this study was to develop a new soil enzyme assay based on hydrodynamic electrochemical detection using a rotating disk electrode in a microliter droplet. The activities of enzymes were determined by measuring the electrochemical oxidation of p-aminophenol (PAP), following the enzymatic conversion of substrate-conjugated PAP. The calibration curves of β-galactosidase (β-gal), β-glucosidase (β-glu) and acid phosphatase (AcP) showed good linear correlation after being spiked in soils using chronoamperometry. We also performed electrochemical detection using real soils. Hydrodynamic chronoamperometry can be used to assess the AcP in soils, with a detection time of only 90 s. Linear sweep voltammetry was used to measure the amount of PAP released from β-gal and β-glu by enzymatic reaction after 60 min. For the assessment of soil enzymes, the results of hydrodynamic voltammetry assay compared favorably to those using a standard assay procedure, but this new procedure is more user-friendly, rapid and simple.

  13. Catalytic Adsorptive Stripping Voltammetry at a Carbon Paste Electrode for the Determination of Amiodarone

    Institute of Scientific and Technical Information of China (English)

    LIU Ning; GAO Wei; SONG Jun-Feng

    2006-01-01

    Voltammetry using solid electrodes usually suffers from the contamination due to the deposition of the redox products of analytes on the electrode surface. The contamination has resulted in poor reproducibility and overelaborate operation procedures. The use of the chemical catalysis of oxidant on the reduction product of analyte not only can eliminate the contamination of analyte to solid electrodes but also can improve the faradaic response of analyte. This work introduced both the catalysis of oxidant K2S2O8 and the enhancement of surfactant Triton X-100 on the faraday response of amiodarone into an adsorptive stripping voltammetry at a carbon paste electrode for the determination of amiodarone. The method exhibits high sensitivity, good reproducibility and simple operation procedure. In 0.2 mol·L-1 HOAc-NaOAc buffer (pH=5.3) containing 2.2 × 10-2 mol·L-1 K2S2O8 and 0.002% Triton X-100, the 2.5th-order derivative stripping peak current of the catalytic wave at 0.3 V (vs. Ag/AgCl) is rectilinear to amiodarone concentration in the range of 2.0× 10-10-2.3× 10-8 mol·L-1 with a detection limit of 1.5× l0-10 mol·L-1 after accumulation at 0 V for 30 s.

  14. Zinc Detection in Serum by Anodic Stripping Voltammetry on Microfabricated Bismuth Electrodes.

    Science.gov (United States)

    Jothimuthu, Preetha; Wilson, Robert A; Herren, Josi; Pei, Xing; Kang, Wenjing; Daniels, Rodney; Wong, Hector; Beyette, Fred; Heineman, William R; Papautsky, Ian

    2013-02-01

    Zinc (Zn) homeostasis is required for a functional immune system. Critically ill patients often exhibit decreased Zn serum concentrations and could potentially benefit from Zn supplementation as a therapeutic strategy. However, the conventional approaches to monitoring Zn are time consuming and costly. This work reports on detection of Zn by anodic stripping voltammetry (ASV) on bismuth electrodes in a microfabricated electrochemical cell. The working potential window of the electrodeposited bismuth film electrode was investigated by cyclic voltammetry, while square wave ASV was used for measuring Zn in acetate buffer and blood serum. Conditions critical to sensing, such as preconcentration potential, preconcentration time, and buffer pH, were optimized for Zn detection. The sensor was successfully calibrated with pH 6 acetate buffer in the physiologically-relevant range of 5 μM to 50μM Zn and exhibited well-defined and highly repeatable peaks. The sensor was used to demonstrate measurement of Zn in blood serum digested in HCl. The results of this work show that Zn detection in serum is possible with smaller sample volumes (μL vs. μL) and faster turnaround time (hours vs. days) as compared with the conventional spectroscopic methods.

  15. Square wave voltammetry with multivariate calibration tools for determination of eugenol, carvacrol and thymol in honey.

    Science.gov (United States)

    Tonello, Natalia; Moressi, Marcela Beatriz; Robledo, Sebastián Noel; D'Eramo, Fabiana; Marioli, Juan Miguel

    2016-09-01

    The simultaneous determination of eugenol (EU), thymol (Ty) and carvacrol (CA) in honey samples, employing square wave voltammetry (SWV) and chemometrics tools, is informed for the first time. For this purpose, a glassy carbon electrode (GCE) was used as working electrode. The operating conditions and influencing parameters (involving several chemical and instrumental parameters) were first optimized by cyclic voltammetry (CV). Thus, the effects of the scan rate, pH and analyte concentration on the electrochemical response of the above mentioned molecules were studied. The results show that the electrochemical responses of the three compounds are very similar and that the voltammetric traces present a high degree of overlap under all the experimental conditions used in this study. Therefore, two chemometric tools were tested to obtain the multivariate calibration model. One method was the partial least squares regression (PLS-1), which assumes a linear behaviour. The other nonlinear method was an artificial neural network (ANN). In this last case we used a supervised, feed-forward network with Levenberg-Marquardt back propagation training. From the accuracies and precisions analysis between nominal and estimated concentrations calculated by using both methods, it was inferred that the ANN method was a good model to quantify EU, Ty and CA in honey samples. Recovery percentages were between 87% and 104%, except for two samples whose values were 136% and 72%. The analytical methodology was simple, fast and accurate.

  16. Determination of trace amounts of morphine in human plasma by anodic adsorptive stripping differential pulse voltammetry

    Institute of Scientific and Technical Information of China (English)

    Ali Niazi; Ateesa Yazdanipour

    2008-01-01

    New adsorptive anodic differential pulse stripping voltammetry method for the direct determination of morphine at trace levels in human plasma of addicts is proposed.The procedure involves an adsorptive accumulation of morphine on a HMDE,followed by oxidation of adsorbed morphine by voltammetry scan using differential pulse modulation.The optimum conditions for the analysis of morphine are pH 10.5,Eacc of - 100 mV (vs.Ag/AgCl),and tacc of 120 s.The peak current is proportional to the concentration of morphine,and a linear calibration graph is obtained at 0.01-3.10 μg mL-1.A relative standard deviation of 1.06% (n=5) was obtained,and the limit of detection was 3 ng mL- 1.The capability of the method for the analysis of real samples was evaluated by the determination of morphine in spiked human plasma and addicts human plasma with satisfactory results.

  17. Thin-layer voltammetry of soluble species on screen-printed electrodes: proof of concept.

    Science.gov (United States)

    Botasini, S; Martí, A C; Méndez, E

    2016-10-17

    Thin-layer diffusion conditions were accomplished on screen-printed electrodes by placing a controlled-weight onto the cast solution and allowing for its natural spreading. The restricted diffusive conditions were assessed by cyclic voltammetry at low voltage scan rates and electrochemical impedance spectroscopy. The relationship between the weight exerted over the drop and the thin-layer thickness achieved was determined, in such a way that the simple experimental set-up designed for this work could be developed into a commercial device with variable control of the thin-layer conditions. The experimental results obtained resemble those reported for the voltammetric features of electroactive soluble species employing electrodes modified with carbon nanotubes or graphene layers, suggesting that the attainment of the benefits reported for these nanomaterials could be done simply by forcing the solution to spread over the screen-printed electrodic system to form a thin layer solution. The advantages of thin-layer voltammetry in the kinetic characterization of quasi-reversible and irreversible processes are highlighted.

  18. Boron doped diamond sensor for sensitive determination of metronidazole: Mechanistic and analytical study by cyclic voltammetry and square wave voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Ammar, Hafedh Belhadj, E-mail: hbelhadjammar@yahoo.fr; Brahim, Mabrouk Ben; Abdelhédi, Ridha; Samet, Youssef

    2016-02-01

    The performance of boron-doped diamond (BDD) electrode for the detection of metronidazole (MTZ) as the most important drug of the group of 5-nitroimidazole was proven using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. A comparison study between BDD, glassy carbon and silver electrodes on the electrochemical response was carried out. The process is pH-dependent. In neutral and alkaline media, one irreversible reduction peak related to the hydroxylamine derivative formation was registered, involving a total of four electrons. In acidic medium, a prepeak appears probably related to the adsorption affinity of hydroxylamine at the electrode surface. The BDD electrode showed higher sensitivity and reproducibility analytical response, compared with the other electrodes. The higher reduction peak current was registered at pH 11. Under optimal conditions, a linear analytical curve was obtained for the MTZ concentration in the range of 0.2–4.2 μmol L{sup −1}, with a detection limit of 0.065 μmol L{sup −1}. - Highlights: • SWV for the determination of MTZ • Boron-doped diamond as a new electrochemical sensor • Simple and rapid detection of MTZ • Efficiency of BDD for sensitive determination of MTZ.

  19. Boron doped diamond sensor for sensitive determination of metronidazole: Mechanistic and analytical study by cyclic voltammetry and square wave voltammetry.

    Science.gov (United States)

    Ammar, Hafedh Belhadj; Brahim, Mabrouk Ben; Abdelhédi, Ridha; Samet, Youssef

    2016-02-01

    The performance of boron-doped diamond (BDD) electrode for the detection of metronidazole (MTZ) as the most important drug of the group of 5-nitroimidazole was proven using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. A comparison study between BDD, glassy carbon and silver electrodes on the electrochemical response was carried out. The process is pH-dependent. In neutral and alkaline media, one irreversible reduction peak related to the hydroxylamine derivative formation was registered, involving a total of four electrons. In acidic medium, a prepeak appears probably related to the adsorption affinity of hydroxylamine at the electrode surface. The BDD electrode showed higher sensitivity and reproducibility analytical response, compared with the other electrodes. The higher reduction peak current was registered at pH11. Under optimal conditions, a linear analytical curve was obtained for the MTZ concentration in the range of 0.2-4.2μmolL(-1), with a detection limit of 0.065μmolL(-1). Copyright © 2015 Elsevier B.V. All rights reserved.

  20. 28 CFR 512.20 - Publication of results of research project.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Publication of results of research project. 512.20 Section 512.20 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE GENERAL MANAGEMENT AND ADMINISTRATION RESEARCH Research § 512.20 Publication of results of research project. (a)...

  1. A Classroom Research Skills Development Emphasizing Data Analysis and Result of SSRU Students by RBL

    Science.gov (United States)

    Waree, Chaiwat

    2017-01-01

    The purpose of the study is the learning using research as a base. To strengthen the skills of classroom research Emphasizing Data Analysis and Result and to study the development of research skills in the class Emphasizing Data Analysis and Result of SSRU' Students by learning using research base. The target group are students in the 2nd semester…

  2. TRANSVAC research infrastructure - Results and lessons learned from the European network of vaccine research and development.

    Science.gov (United States)

    Geels, Mark J; Thøgersen, Regitze L; Guzman, Carlos A; Ho, Mei Mei; Verreck, Frank; Collin, Nicolas; Robertson, James S; McConkey, Samuel J; Kaufmann, Stefan H E; Leroy, Odile

    2015-10-05

    TRANSVAC was a collaborative infrastructure project aimed at enhancing European translational vaccine research and training. The objective of this four year project (2009-2013), funded under the European Commission's (EC) seventh framework programme (FP7), was to support European collaboration in the vaccine field, principally through the provision of transnational access (TNA) to critical vaccine research and development (R&D) infrastructures, as well as by improving and harmonising the services provided by these infrastructures through joint research activities (JRA). The project successfully provided all available services to advance 29 projects and, through engaging all vaccine stakeholders, successfully laid down the blueprint for the implementation of a permanent research infrastructure for early vaccine R&D in Europe.

  3. Evaluating the Passivation of Corrosion of API-X100 Steel with Cyclic Voltammetry

    Science.gov (United States)

    Eliyan, Faysal Fayez; Alfantazi, Akram

    2017-10-01

    In this research, cyclic voltammetry, in oxygen-free low bicarbonate-carbonate solutions, was used to study the corrosion reactions of a high-strength steel, API-X100. With cycles of different scan ranges, the effects of cycling, transpassivation, and cathodic reduction on the electrochemistry of the passive films were analyzed. It was found that carbonate in higher concentrations reduces the anodic activity and the cathodic reactions of the surface. Bicarbonate in small concentrations in solutions that contained low carbonate concentrations catalyzed dissolution and disrupted the formation of the passive films, in reference to the measured anodic currents. From the experiments, there was electrochemical evidence that with more cycles, the passive films were growing thicker, the transpassivation deteriorated the passive films, and during the cathodic reduction, the dissolution was occurring at lower potentials to facilitate later the passivation at higher potentials.

  4. DNA-binding Studies of Daunorubicin in the Presence of Methylene Blue by Spectroscopy and Voltammetry Techniques

    Institute of Scientific and Technical Information of China (English)

    HAJIAN Reza; SHAMS Nafiseh; PARVIN Afsaneh

    2009-01-01

    The interaction of daunorubicin with calf thymus DNA has been investigated with the use of methylene blue dye as a spectral probe by the application of UV-Vis spectrophotometry, spectrofluorometry and voltammetry. The voltammetric behavior of daunorubicin has been investigated at a glassy carbon electrode using cyclic and differen-tial pulse voitammetry. Both UV-vis spectrophotometry and cyclic voltammetry studies confirmed the intercalation reaction. The results showed that both daunorubicin and methylene blue molecules could intercalate into the double helix of DNA. The apparent binding constant of daunorubicin with DNA has been found to be 7.8 × 104 L˙mol-1.The fluorescence signal of daunorubicin and methylene blue was quenched with DNA addition. The Stern-Volmer equation was plotted based on the quenching fluorescence signal of daunorubicin.

  5. Poly(glutamic acid) nanofibre modified glassy carbon electrode: Characterization by atomic force microscopy, voltammetry and electrochemical impedance

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Daniela Pereira; Zanoni, Maria Valnice Boldrin; Bergamini, Marcio Fernando [Departamento de Quimica Analitica, Instituto de Quimica, Universidade Estadual Paulista, Caixa Postal 355, 14800-900 Araraquara, S.P. (Brazil); Chiorcea-Paquim, Ana-Maria; Diculescu, Victor Constantin [Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra (Portugal); Oliveira Brett, Ana-Maria [Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade de Coimbra, 3004-535 Coimbra (Portugal)], E-mail: brett@ci.uc.pt

    2008-04-20

    Glassy carbon electrodes (GCE) were modified with poly(glutamic acid) acid films prepared using three different procedures: glutamic acid monomer electropolymerization (MONO), evaporation of poly(glutamic acid) (PAG) and evaporation of a mixture of poly(glutamic acid)/glutaraldehyde (PAG/GLU). All three films showed good adherence to the electrode surface. The performance of the modified GCE was investigated by cyclic voltammetry and differential pulse voltammetry, and the films were characterized by atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS). The three poly(glutamic acid) modified GCEs were tested using the electrochemical oxidation of ascorbic acid and a decrease of the overpotential and the improvement of the oxidation peak current was observed. The PAG modified electrode surfaces gave the best results. AFM morphological images showed a polymeric network film formed by well-defined nanofibres that may undergo extensive swelling in solution, allowing an easier electron transfer and higher oxidation peaks.

  6. Voltammetric Study and Determination of Phenylephrine Hydrochloride at INP-Nafion-Modified CPE Sensor Employing Differential Pulse Voltammetry

    Directory of Open Access Journals (Sweden)

    Zeinab Pourghobadi

    2014-03-01

    Full Text Available In this study, describes the voltammetric oxidation and determination of phenylephrine (PHE hydrochloride at a new chemically modified electrode. Iron nanoparticle (INPs was dispersed in Nafion solution to obtain a INP-Nafion-modified CPE for the voltammetric analysis of PHE .The electrochemical behaviour of PHE on INP-Nafion-modified CPE was studied, using cyclic voltammetry as a diagnostic technique. The effects of amount of INPs-Nafion dispersion, pH, and scan rate on the response of modified electrode for the oxidation of PHE were investigated. Using differential pulse voltammetry (DPV, the modified electrode indicated a dynamic linear range for quantitative determination of PHE in the range of 5 μM−130 μM, and the detection limit was estimated to be 0.76 μM. The method was developed for the determination of PHE in pharmaceutical samples with satisfactory results.

  7. Computer-controlled instrumentation for fast voltammetry at ultramicroelectrodes

    Science.gov (United States)

    Pospíšil, L.; Fiedler, J.; Fanelli, N.

    2000-04-01

    In this article we describe an electrochemical experimental setup for cyclic voltammetry operating from low (1 V/s) to very high (200 kV/s) scan rates. The system is designed to achieve an acceptable cost and to be user friendly for nonexperts. The instrumentation is based on a commercial arbitrary wave form generator, a digital oscilloscope, a general purpose interface bus interface to a PC, and a laboratory-built potentiostat. There are no complicated manual operations, instead the software creates dialog with an operator to control commands for the instruments. Requirements for the wave form synthesis and the data acquisition are given. Various data-smoothing methods for treating 8-bit fast scan data are evaluated. The performance was tested on the oxidation of ferrocene in acetonitrile. The estimated value of the standard heterogeneous rate constant, k0=0.8±0.1 cms-1, is in reasonable agreement with the most recent reports from other laboratories.

  8. Study of quinones reactions with wine nucleophiles by cyclic voltammetry.

    Science.gov (United States)

    Oliveira, Carla M; Barros, António S; Ferreira, António C S; Silva, Artur M S

    2016-11-15

    Quinones are electrophilic species which can react with various nucleophiles, like wine antioxidants, such as sulfur dioxide or ascorbic acid, thiols, amino acids, and numerous polyphenols. These reactions are very important in wine aging because they mediate oxygen reactions during both production and bottle aging phases. In this work, the major challenge was to determine the interaction between ortho-quinones and wine nucleophiles (amino acids, thiols, and the antioxidants SO2 and ascorbic acid), by cyclic voltammetry. Wine-model solutions with gallic acid, caffeic acid, or (+)-catechin and nucleophilic compounds were used. To understand the effect of nucleophilic addition in wine, a white wine with the same added nucleophiles was also analysed. Cyclic voltammograms were taken with glassy carbon electrode or screen-printed carbon electrodes, respectively, for wine-model and white wines solutions, in the absence and in the presence of nucleophiles. A nucleophilic order profile related to the cathodic current intensity decrease was observed.

  9. Nanoalloy electrocatalysis: simulating cyclic voltammetry from configurational thermodynamics with adsorbates.

    Science.gov (United States)

    Wang, Lin-Lin; Tan, Teck L; Johnson, Duane D

    2015-11-14

    We simulate the adsorption isotherms for alloyed nanoparticles (nanoalloys) with adsorbates to determine cyclic voltammetry (CV) during electrocatalysis. The effect of alloying on nanoparticle adsorption isotherms is provided by a hybrid-ensemble Monte Carlo simulation that uses the cluster expansion method extended to non-exchangeable coupled lattices for nanoalloys with adsorbates. Exemplified here for the hydrogen evolution reaction, a 2-dimensional CV is mapped for Pd-Pt nanoalloys as a function of both electrochemical potential and the global Pt composition, and shows a highly non-linear alloying effect on CV. Detailed features in CV arise from the interplay among the H-adsorption in multiple sites that is closely correlated with alloy configurations, which are in turn affected by the H-coverage. The origins of specific features in CV curves are assigned. The method provides a more complete means to design nanoalloys for electrocatalysis.

  10. Underpotential deposition and anodic stripping voltammetry at mesoporous microelectrodes.

    Science.gov (United States)

    Sanchez, Pablo Lozano; Elliott, Joanne M

    2005-05-01

    Using the technique of liquid crystal templating a series of high surface area mesoporous platinum microelectrodes was fabricated. The underpotential deposition of metal ions at such electrodes was found to be similar to that at conventional platinum electrodes. The phenomena of underpotential deposition, in combination with the intrinsic properties of mesoporous microelectrodes (i.e. a high surface area and efficient mass transport) was exploited for the purpose of anodic stripping voltammetry. In particular the underpotential deposition of Ag(+), Pb(2+) and Cu(2+) ions was investigated and it was found that mesoporous microelectrodes were able to quantify the concentration of ions in solution down to the ppb range. The overall behaviour of the mesoporous electrodes was found to be superior to that of conventional microelectrodes and the effects of interference by surfactants were minimal.

  11. Determination of Pesticide Ethion by Linear Sweep Stripping Voltammetry

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The presence of the pesticide ethion was determined using an electroanalytical method, i. e. , linear sweep stripping voltammetry at a hanging mercury drop electrode in the Britton-Robbinson buffer with pH = 8. 36, based on its reduction peak observed at - 690 mV following its alkaline hydrolysis. The experimental parameters, namely, the preconcentration potential, the preconcentration time, and the scan rate were investigated and -300 mV (vs. Ag/AgCl), 270 s, and 100 mV/s were selected as the optimal values, respectively. The linear relationship between the peak current and the concentration was found to be in the range of 0. 02-0. 16 mg/L, with a detection limit of 0.0087 mg/L. The proposed method was applied to the determination of ethion in spiked vegetable and fruit samples via a preextraction with anhydrous ethanol.

  12. Cloud Point Extraction for Electroanalysis: Anodic Stripping Voltammetry of Cadmium.

    Science.gov (United States)

    Rusinek, Cory A; Bange, Adam; Papautsky, Ian; Heineman, William R

    2015-06-16

    Cloud point extraction (CPE) is a well-established technique for the preconcentration of hydrophobic species from water without the use of organic solvents. Subsequent analysis is then typically performed via atomic absorption spectroscopy (AAS), UV-vis spectroscopy, or high performance liquid chromatography (HPLC). However, the suitability of CPE for electroanalytical methods such as stripping voltammetry has not been reported. We demonstrate the use of CPE for electroanalysis using the determination of cadmium (Cd(2+)) by anodic stripping voltammetry (ASV). Rather than using the chelating agents which are commonly used in CPE to form a hydrophobic, extractable metal complex, we used iodide and sulfuric acid to neutralize the charge on Cd(2+) to form an extractable ion pair. This offers good selectivity for Cd(2+) as no interferences were observed from other heavy metal ions. Triton X-114 was chosen as the surfactant for the extraction because its cloud point temperature is near room temperature (22-25 °C). Bare glassy carbon (GC), bismuth-coated glassy carbon (Bi-GC), and mercury-coated glassy carbon (Hg-GC) electrodes were compared for the CPE-ASV. A detection limit for Cd(2+) of 1.7 nM (0.2 ppb) was obtained with the Hg-GC electrode. ASV with CPE gave a 20x decrease (4.0 ppb) in the detection limit compared to ASV without CPE. The suitability of this procedure for the analysis of tap and river water samples was demonstrated. This simple, versatile, environmentally friendly, and cost-effective extraction method is potentially applicable to a wide variety of transition metals and organic compounds that are amenable to detection by electroanalytical methods.

  13. Investigations on the use of anodic stripping voltammetry for the analyses of lead in saline environments

    Energy Technology Data Exchange (ETDEWEB)

    Case, C.W.

    1978-08-01

    Research is reported directed to modification of the anodic stripping voltammetry (ASV) analytic method in order to acquire data for lead from ambient sea water conditions, and development of a chemical model which uses these data to identify inorganic lead species for saline environments. Laboratory and field samples were analyzed for lead partitioning in: (a) KCl electrolyte solutions; (b) I.A.P.S.O. Standard Sea Water; (c) seawater samples from Quatsino Sound, British Columbia; (d) a series of seawater samples from San Francisco Bay; and (e) seawater samples from the Gulf of Mexico. The electrochemical traits of the lead species and the ASV oxidation potential expression are the fundamental constituents of the chemical model. The model uses the data from the analyses to provide the mass balance relationships for lead partitioned among the major anions in seawater. The laboratory analyses of KCl electrolyte and Standard Seawater give the following results. The modified ASV method and chemical model provide information on ambient labile and non-labile inorganic lead complexes in these saline solutions down to the parts-per-billion level. No purge and the simple electrodes cause some erratic behavior and spurious potentials, but the data are reproducible. In addition to Pb/sup 2 +/, the most dominant measured lead species in order include PbCO/sub 3//sup 0/, PbSO/sub 4//sup 0/, PbCl/sup +/, and Pb(NO/sub 3/)/sub 2//sup 0/ from the lead additions solution. The analyses of the field samples give the following results. Samples were taken from the partially anoxic basin in Quatsino Sound, British Columbia with one successful analysis which is for somewhat normal dissolved oxygen conditions. Data show that lead is partitioned among Pb/sup 2 +/, Pb(OH)/sub 2//sup 0/, PbCO/sub 3//sup 0/, and PbSO/sub 4//sup 0/. The analyses with purge for the San Francisco Bay water partitions lead among Pb/sup 2 +/, PbCO/sub 3//sup 0/, PbSO/sub 4//sup 0/, PbCl/sup +/, and Pb

  14. Total oxidant-scavenging capacities of plasma from glycogen storage disease type Ia patients as measured by cyclic voltammetry, FRAP and luminescence techniques.

    Science.gov (United States)

    Koren, E; Lipkin, J; Klar, A; Hershkovitz, E; Ginsburg, I; Kohen, R

    2009-10-01

    It has been suggested that the very low incidence of atherosclerosis in glycogen storage disease type Ia (GSD Ia) subjects might be attributed to elevated levels of uric acid, one of the potent low molecular- weight antioxidants found in plasma. The present communication describes a use of two analytical methods-cyclic voltammetry and ferric reducing ability of plasma-and also two chemiluminescence methods to evaluate the total oxidant-scavenging capacities (TOSC) of plasma from GSD Ia patients. Our results verified the elevation of TOSC in GSD Ia patients and we propose the inclusion of luminescence and cyclic voltammetry assays as reliable methods for estimating TOSC in a variety of clinical disorders. Our findings with the cyclic voltammetry method add support to the assumption that the elevated uric acid levels might be the main contributor to plasma antioxidant capacity and possible protection against atherosclerosis.

  15. Cyclic voltammetry deposition of copper nanostructure on MWCNTs modified pencil graphite electrode: An ultra-sensitive hydrazine sensor

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, Hamid [Faculty of Sciences, Razi University, Kermanshah (Iran, Islamic Republic of); Gholivand, Mohammad B., E-mail: mbgholivand@razi.ac.ir [Faculty of Sciences, Razi University, Kermanshah (Iran, Islamic Republic of); Abdolmaleki, Abbas [Department of Chemistry, Malek Ashtar University of Technology, Tehran (Iran, Islamic Republic of)

    2016-09-01

    In this study, Copper (Cu) nanostructures (CuNS) were electrochemically deposited on a film of multiwall carbon nanotubes (MWCNTs) modified pencil graphite electrode (MWCNTs/PGE) by cyclic voltammetry method to fabricate a CuNS–MWCNTs composite sensor (CuNS–MWCNT/PGE) for hydrazine detection. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of CuNS on the MWCNTs matrix. The composite of CuNS-MWCNTs was characterized with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The preliminary studies showed that the proposed sensor have a synergistic electrocatalytic activity for the oxidation of hydrazine in phosphate buffer. The catalytic currents of square wave voltammetry had a linear correlation with the hydrazine concentration in the range of 0.1 to 800 μM with a low detection limit of 70 nM. Moreover, the amperometric oxidation current exhibited a linear correlation with hydrazine concentration in the concentration range of 50–800 μM with the detection limit of 4.3 μM. The proposed electrode was used for the determination of hydrazine in real samples and the results were promising. Empirical results also indicated that the sensor had good reproducibility, long-term stability, and the response of the sensor to hydrazine was free from interferences. Moreover, the proposed sensor benefits from simple preparation, low cost, outstanding sensitivity, selectivity, and reproducibility for hydrazine determination. - Highlights: • The Copper nanostructures (CuNS) were prepared by cyclic voltammetry deposition. • The CuNS-MWCNT/PGE sensor shows high activity toward hydrazine (N{sub 2}H{sub 4}). • The proposed sensor exhibits a wide linear range (0.1 to 800 μM), low detection limit (70 nM), high sensitivity and stability for hydrazine.

  16. Study of Copper and Purine-Copper Complexes on Modified Carbon Electrodes by Cyclic and Elimination Voltammetry

    Directory of Open Access Journals (Sweden)

    Frantisek Jelen

    2008-01-01

    Full Text Available Using a paraffin impregnated graphite electrode (PIGE and mercury-modifiedpyrolytic graphite electrode with basal orientation (Hg-PGEb copper(II and Cu(II-DNApurine base solutions have been studied by cyclic (CV and linear sweep voltammetry(LSV in connection with elimination voltammetry with linear scan (EVLS. In chlorideand bromide solutions (pH 6, the redox process of Cu(II proceeded on PIGE with twocathodic and two anodic potentially separated signals. According to the eliminationfunction E4, the first cathodic peak corresponds to the reduction Cu(II e- → Cu(I withthe possibility of fast disproportionation 2Cu(I → Cu(II Cu(0. The E4 of the secondcathodic peak signalized an electrode process controlled by a surface reaction. Theelectrode system of Cu(II on Hg-PGEb in borate buffer (pH 9.2 was characterized by onecathodic and one anodic peak. Anodic stripping voltammetry (ASV on PIGE and cathodicstripping voltammetry (CSV on Hg-PGEb were carried out at potentials where thereduction of copper ions took place and Cu(I-purine complexes were formed. By usingASV and CSV in combination with EVLS, the sensitivity of Cu(I-purine complexdetection was enhanced relative to either ASV or CSV alone, resulting in higher peakcurrents of more than one order of magnitude. The statistical treatment of CE data wasused to determine the reproducibility of measurements. Our results show that EVLS inconnection with the stripping procedure is useful for both qualitative and quantitativemicroanalysis of purine derivatives and can also reveal details of studied electrodeprocesses.

  17. Study of Copper and Purine-Copper Complexes on Modified Carbon Electrodes by Cyclic and Elimination Voltammetry.

    Science.gov (United States)

    Trnkova, Libuse; Zerzankova, Lenka; Dycka, Filip; Mikelova, Radka; Jelen, Frantisek

    2008-01-24

    Using a paraffin impregnated graphite electrode (PIGE) and mercury-modifiedpyrolytic graphite electrode with basal orientation (Hg-PGEb) copper(II) and Cu(II)-DNApurine base solutions have been studied by cyclic (CV) and linear sweep voltammetry(LSV) in connection with elimination voltammetry with linear scan (EVLS). In chlorideand bromide solutions (pH 6), the redox process of Cu(II) proceeded on PIGE with twocathodic and two anodic potentially separated signals. According to the eliminationfunction E4, the first cathodic peak corresponds to the reduction Cu(II) e⁻ → Cu(I) withthe possibility of fast disproportionation 2Cu(I) → Cu(II) Cu(0). The E4 of the secondcathodic peak signalized an electrode process controlled by a surface reaction. Theelectrode system of Cu(II) on Hg-PGEb in borate buffer (pH 9.2) was characterized by onecathodic and one anodic peak. Anodic stripping voltammetry (ASV) on PIGE and cathodicstripping voltammetry (CSV) on Hg-PGEb were carried out at potentials where thereduction of copper ions took place and Cu(I)-purine complexes were formed. By usingASV and CSV in combination with EVLS, the sensitivity of Cu(I)-purine complexdetection was enhanced relative to either ASV or CSV alone, resulting in higher peakcurrents of more than one order of magnitude. The statistical treatment of CE data wasused to determine the reproducibility of measurements. Our results show that EVLS inconnection with the stripping procedure is useful for both qualitative and quantitativemicroanalysis of purine derivatives and can also reveal details of studied electrodeprocesses.

  18. Study of Copper and Purine-Copper Complexes on Modified Carbon Electrodes by Cyclic and Elimination Voltammetry

    Science.gov (United States)

    Trnkova, Libuse; Zerzankova, Lenka; Dycka, Filip; Mikelova, Radka; Jelen, Frantisek

    2008-01-01

    Using a paraffin impregnated graphite electrode (PIGE) and mercury-modified pyrolytic graphite electrode with basal orientation (Hg-PGEb) copper(II) and Cu(II)-DNA purine base solutions have been studied by cyclic (CV) and linear sweep voltammetry (LSV) in connection with elimination voltammetry with linear scan (EVLS). In chloride and bromide solutions (pH 6), the redox process of Cu(II) proceeded on PIGE with two cathodic and two anodic potentially separated signals. According to the elimination function E4, the first cathodic peak corresponds to the reduction Cu(II) + e- → Cu(I) with the possibility of fast disproportionation 2Cu(I) → Cu(II)+ Cu(0). The E4 of the second cathodic peak signalized an electrode process controlled by a surface reaction. The electrode system of Cu(II) on Hg-PGEb in borate buffer (pH 9.2) was characterized by one cathodic and one anodic peak. Anodic stripping voltammetry (ASV) on PIGE and cathodic stripping voltammetry (CSV) on Hg-PGEb were carried out at potentials where the reduction of copper ions took place and Cu(I)-purine complexes were formed. By using ASV and CSV in combination with EVLS, the sensitivity of Cu(I)-purine complex detection was enhanced relative to either ASV or CSV alone, resulting in higher peak currents of more than one order of magnitude. The statistical treatment of CE data was used to determine the reproducibility of measurements. Our results show that EVLS in connection with the stripping procedure is useful for both qualitative and quantitative microanalysis of purine derivatives and can also reveal details of studied electrode processes. PMID:27879715

  19. Cyclic voltammetry deposition of copper nanostructure on MWCNTs modified pencil graphite electrode: An ultra-sensitive hydrazine sensor.

    Science.gov (United States)

    Heydari, Hamid; Gholivand, Mohammad B; Abdolmaleki, Abbas

    2016-09-01

    In this study, Copper (Cu) nanostructures (CuNS) were electrochemically deposited on a film of multiwall carbon nanotubes (MWCNTs) modified pencil graphite electrode (MWCNTs/PGE) by cyclic voltammetry method to fabricate a CuNS-MWCNTs composite sensor (CuNS-MWCNT/PGE) for hydrazine detection. Scanning electron microscopy (SEM) and Energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of CuNS on the MWCNTs matrix. The composite of CuNS-MWCNTs was characterized with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The preliminary studies showed that the proposed sensor have a synergistic electrocatalytic activity for the oxidation of hydrazine in phosphate buffer. The catalytic currents of square wave voltammetry had a linear correlation with the hydrazine concentration in the range of 0.1 to 800μM with a low detection limit of 70nM. Moreover, the amperometric oxidation current exhibited a linear correlation with hydrazine concentration in the concentration range of 50-800μM with the detection limit of 4.3μM. The proposed electrode was used for the determination of hydrazine in real samples and the results were promising. Empirical results also indicated that the sensor had good reproducibility, long-term stability, and the response of the sensor to hydrazine was free from interferences. Moreover, the proposed sensor benefits from simple preparation, low cost, outstanding sensitivity, selectivity, and reproducibility for hydrazine determination. Copyright © 2016. Published by Elsevier B.V.

  20. Research plan and preliminary results - A field research site for emerging contaminants in Iowa

    Science.gov (United States)

    Schnoebelen, Douglas J.; Kolpin, Dana W.; Barber, Larry B.; Furlong, Edward T.; Meyer, Michael; Skopec, M.

    2006-01-01

    Research has recently documented the prevalence of a wide variety of pharmaceuticals and other emerging contaminants (ECs) in streams across the United States. Wastewater treatment plants (WWTPs) have been found to be an important source and collection point of ECs to streams as many ECs are incompletely removed during treatment. To investigate the complex in-stream processes (e.g., dilution, sorption, degradation, dispersion, etc.) that can affect ECs following their input from a WWTP and determining if such input is having an effect on the aquatic ecosystem requires the integration of multi-disciplinary efforts at a carefully selected field site. Preliminary work has identified an 8-km reach of Fourmile Creek in central Iowa as an ideal research site to investigate such important research questions pertaining to ECs. Unique aspects of Fourmile Creek included: (1) it single source effluent-dominated stream, (2) background data document the input of a wide variety of ECs from WWTP discharge, (3) small basin size, (4) relatively simple flow system, (5) background data suggest that undefined processes are taking place decreasing the level of select ECs during stream transport, (6) the WWTP uses a treatment technology (activated sludge) typical of many towns in Iowa and the United States (7) a hydrogeologic setting of a low-gradient, small stream (average discharge less than 1.41 m³/s) in glacial drift is typical of many areas in Iowa and across the Midwest, and (8) the existence of a low-head clam approximately 2 km upstream of the WWTP outfall allowing more accurate "above WWTP" and "below WWTP" comparisons in aquatic ecosystems. Furthermore, the WWTP is scheduled to close by 2011 providing a unique opportunity to determine how stream hydrology, water chemistry and aquatic biota react to the removal of the primary source of flow and ECs in this system. This will allow a novel "before" and "after" assessment not previously available in EC research. Research to date

  1. Critical infrastructure protection research results of the first critical infrastructure protection research project in Hungary

    CERN Document Server

    Padányi, József

    2016-01-01

    This book presents recent research in the recognition of vulnerabilities of national systems and assets which gained special attention for the Critical Infrastructures in the last two decades. The book concentrates on R&D activities in the relation of Critical Infrastructures focusing on enhancing the performance of services as well as the level of security. The objectives of the book are based on a project entitled "Critical Infrastructure Protection Researches" (TÁMOP-4.2.1.B-11/2/KMR-2011-0001) which concentrated on innovative UAV solutions, robotics, cybersecurity, surface engineering, and mechatrinics and technologies providing safe operations of essential assets. This report is summarizing the methodologies and efforts taken to fulfill the goals defined. The project has been performed by the consortium of the Óbuda University and the National University of Public Service.

  2. Voltammetry and Electrocatalysis of Achrornobacter Xylosoxidans Copper Nitrite Reductase on Functionalized Au(111)-Electrode Surfaces

    DEFF Research Database (Denmark)

    Welinder, Anna C.; Zhang, Jingdong; Hansen, Allan G.;

    2007-01-01

    A long-standing issue in protein film voltammetry (PFV), particularly electrocatalytic voltammetry of redox enzyme monolayers, is the variability of protein adsorption modes, reflected in distributions of catalytic activity of the adsorbed protein/enzyme molecules. Use of well-defined, atomically...

  3. Cell-based chip for the detection of anticancer effect on HeLa cells using cyclic voltammetry.

    Science.gov (United States)

    El-Said, Waleed Ahmed; Yea, Cheol-Heon; Kim, Hyunhee; Oh, Byung-Keun; Choi, Jeong-Woo

    2009-01-01

    HeLa cells directly immobilized on gold-patterned silicon substrate were used to assess the biological toxicity of anticancer drugs (hydroxyurea and cyclophosphamide). Immobilization of HeLa cells was confirmed by optical microscopy, and cell growth, viability and drug-related toxicity were examined by cyclic voltammetry and potentiometric stripping analysis. The voltammetric behaviors of HeLa cells displayed a quasi-reversible pattern with the peak current exhibiting a linear relationship with cell number. The attached living cells were exposed to different concentrations of hydroxyurea and cyclophosphamide as anticancer drugs, which induced the change of cyclic voltammetry current peak. As the exposed concentration of anticancer drugs was increased, the change of current peak was increased, which indicates the decrease of cell viability. Trypan Blue dyeing was performed to confirm the results of the effect of anticancer drugs on the cell viability which was obtained from cyclic voltammetry assay. The proposed direct cell immobilization method technique can be applied to the fabrication of cell chip for diagnosis, drug detection, and on-site monitoring.

  4. Differential pulse and square-wave cathodic stripping voltammetry of xanthine and xanthosine at a mercury electrode.

    Science.gov (United States)

    Temerk, Y M; Kamal, M M; Ahmed, G A W; Ibrahim, H S M

    2003-08-01

    The surface activity of xanthine (Xan) and xanthosine (Xano) at a hanging mercury drop electrode (HMDE) was studied using out-of-phase ac and cyclic dc voltammetry. The results show that Xan and Xano were strongly adsorbed and chemically interacted with the charged mercury surface, which is the prerequisite step for applying the cathodic adsorptive stripping voltammetric determination of such biologically important compounds. Differential pulse cathodic adsorptive stripping voltammetry (DPCASV) and square-wave cathodic adsorptive stripping voltammetry (SWCASV) were applied for the ultratrace determination of Xan and Xano compounds. Moreover, a rapid and sensitive controlled adsorptive accumulation of Cu(II) complexes of both compounds provided the basis of a direct stripping voltammetric determination of such compounds to submicromolar and nanomolar levels. Operational and solution conditions for the quantitative ultratrace determination of Xan and Xano were optimized in absence and presence of Cu(II). The calibration curve data were subjected to least-squares refinements. The effects of several types of inorganic and organic interfering species on the determination of Xan or Xano were considered.

  5. Femtomolar Detection of Silver Nanoparticles by Flow-Enhanced Direct-Impact Voltammetry at a Microelectrode Array.

    Science.gov (United States)

    Sokolov, Stanislav V; Bartlett, Thomas R; Fair, Peter; Fletcher, Stephen; Compton, Richard G

    2016-09-06

    We report the femtomolar detection of silver (Ag) nanoparticles by direct-impact voltammetry. This is achieved through the use of a random array of microelectrodes (RAM) integrated into a purpose-built flow cell, allowing combined diffusion and convection to the electrode surface. A coupled RAM-flow cell system is implemented and is shown to give reproducible wall-jet type flow characteristics, using potassium ferrocyanide as a molecular redox species. The calibrated flow system is then used to detect and quantitatively size Ag nanoparticles at femtomolar concentrations. Under flow conditions, it is found the nanoparticle impact frequency increases linearly with the volumetric flow rate. The resulting limit of detection is more than 2 orders of magnitude smaller than the previous detection limit for direct-impact voltammetry (900 fM) [J. Ellison et al. Sens. Actuators, B 2014, 200, 47], and is more than 30 times smaller than the previous detection limit for mediated-impact voltammetry (83 fM) [T. M. Alligrant et al. Langmuir 2014, 30, 13462].

  6. Critical appraisal of quantitative PCR results in colorectal cancer research: Can we rely on published qPCR results?

    NARCIS (Netherlands)

    Dijkstra, J.R.; Kempen, L.C.L.T. van; Nagtegaal, I.D.; Bustin, S.A.

    2014-01-01

    The use of real-time quantitative polymerase chain reaction (qPCR) in cancer research has become ubiquitous. The relative simplicity of qPCR experiments, which deliver fast and cost-effective results, means that each year an increasing number of papers utilizing this technique are being published. B

  7. A brief review: Ultrafast electron diffractive voltammetry: General formalism and applications

    CERN Document Server

    Chang, Kiseok; Tao, Zhensheng; Han, Tzong-Ru T; Ruan, Chong-Yu

    2013-01-01

    We present a general formalism of ultrafast diffractive voltammetry approach as a contact-free tool to investigate the ultrafast surface charge dynamics in nanostructured interfaces. As case studies, the photoinduced surface charging processes in oxidized silicon surface and the hot electron dynamics in nanoparticle-decorated interface are examined based on the diffractive voltammetry framework. We identify that the charge redistribution processes appear on the surface, sub-surface, and vacuum levels when driven by intense femtosecond laser pulses. To elucidate the voltammetry contribution from different sources, we perform controlled experiments using shadow imaging techniques and N-particle simulations to aid the investigation of the photovoltage dynamics in the presence of pho- toemission. We show that voltammetry contribution associated with photoemission has a long decay tail and plays a more visible role in the nanosecond timescale, whereas the ultrafast voltammetry are dominated by local charge transfe...

  8. Voltammetry and fluorescence studies on the interaction between Eu (phen)33+ and DNA

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The binding mode of Eu(phen) 33+ with DNA is studied by fluorescence and voltammetric methods. From theScatchard graph and the fluorescence quenching phenomenon, it is concluded that the mode of interaction betweenEu(phen) 33+ and DNA is intercalation bind by inserting the phen π-π conjugate surface between the base pairs of theDNA duplex. Voltammetry was used to confirm the results obtained from the fluorescence method, the result from bothmethods agrees with each other. The binding constant (K) and the binding site size (ns) were calculated from voltammetricdata such as the shifts in potential and limiting currents in the process of adding DNA, according to the positive shifts ofpeak potential. It was considered that the complex of the +2 ion interacted more favorably with the nucleotide bases thanthat of the +3 ion by hydrophobic interaction.

  9. Protein film voltammetry and co-factor electron transfer dynamics in spinach photosystem II core complex.

    Science.gov (United States)

    Zhang, Yun; Magdaong, Nikki; Frank, Harry A; Rusling, James F

    2014-05-01

    Direct protein film voltammetry (PFV) was used to investigate the redox properties of the photosystem II (PSII) core complex from spinach. The complex was isolated using an improved protocol not used previously for PFV. The PSII core complex had high oxygen-evolving capacity and was incorporated into thin lipid and polyion films. Three well-defined reversible pairs of reduction and oxidation voltammetry peaks were observed at 4 °C in the dark. Results were similar in both types of films, indicating that the environment of the PSII-bound cofactors was not influenced by film type. Based on comparison with various control samples including Mn-depleted PSII, peaks were assigned to chlorophyll a (Chl a) (Em = -0.47 V, all vs. NHE, at pH 6), quinones (-0.12 V), and the manganese (Mn) cluster (Em = 0.18 V). PFV of purified iron heme protein cytochrome b-559 (Cyt b-559), a component of PSII, gave a partly reversible peak pair at 0.004 V that did not have a potential similar to any peaks observed from the intact PSII core complex. The closest peak in PSII to 0.004 V is the 0.18 V peak that was found to be associated with a two-electron process, and thus is inconsistent with iron heme protein voltammetry. The -0.47 V peak had a peak potential and peak potential-pH dependence similar to that found for purified Chl a incorporated into DMPC films. The midpoint potentials reported here may differ to various extents from previously reported redox titration data due to the influence of electrode double-layer effects. Heterogeneous electron transfer (hET) rate constants were estimated by theoretical fitting and digital simulations for the -0.47 and 0.18 V peaks. Data for the Chl a peaks were best fit to a one-electron model, while the peak assigned to the Mn cluster was best fit by a two-electron/one-proton model.

  10. Studies on the Nucleophilicity and Scavenge of Superoxide Ion by Cyclic Voltammetry

    Institute of Scientific and Technical Information of China (English)

    Wei Ying-liang; Dang Xue-ping; Hu Sheng-shui

    2003-01-01

    Superoxide ion was generated by the electrochemical reduction of oxygen at a platinum electrode in dimethylsulphoxide (DMSO). This work was focused on the nucleophilicity and scavenge of electrogenerated-superoxide ion by cyclic voltammetry. The nucleophilic displacement reactions of superoxide ion with ethyl acetate and diethyl adipate were discussed and the reason for remarkable influence of diethyl adipate was elucidated. The scavenging activity of ascorbic acid was evaluated and the result allowed the conclusion that the scavenging ability of ascorbic acid is much lower in DMSO than in aqueous phase. UV-spectrum of electrogenerated superoxide ion in DMSO exhibited a single absorption band with λmax at 275 nm, which certified further that the method of electrogeneration was reliable and superoxide ion was stable in DMSO.

  11. Studies on the Nucleophilicity and Scavenge of Superoxide Ion by Cyclic Voltammetry

    Institute of Scientific and Technical Information of China (English)

    WeiYing-liang; DangXue-ping; HuSheng-shui

    2003-01-01

    Superoxide ion was generated by the electro-chemical reduction of oxygen at a platinum electrode in dimethylsulphoxide (DMSO). This work was focused on the nucleophilicity and scavenge of electrogenemted-superoxide ion by cyclic voltammetry. The nucleophilic displacement reactions of superoxide ion with ethyl acetate and diethyl adipate were discussed and the reason for remarkable influence of diethyl adipate was elucidated. The scavenging activity of ascorbic acid was evaluated and the result allowed the conclusion that the scavenging ability of ascorbic acid is much lower in DMSO than in aqueous phasc UV-spectrum of electrogenerated superoxide ion in DMSO exhibited a single absorption band with λmax at 275 nm, which certified further that the method of electrogeneration was reliable and superoxide ion was stable in DMSO.

  12. Electrochemical characterization of lithium ferrite electrodes through cyclic voltammetry and Raman spectra

    Energy Technology Data Exchange (ETDEWEB)

    Manley, M.; Cook, W. [Univ. of New Brunswick, Dept. of Chemical Engineering, Fredericton, New Brunswick (Canada)

    2013-07-01

    Lithium ferrite, a mixed spinel with the formula, Fe[Li{sub 0.5}Fe{sub 1.5}]O{sub 4} or LiFe{sub 5}O{sub 8}, has been synthesized and characterized in both its ordered (α) and disordered (β) phases. In an effort to scope the electrochemical activity lithium ferrite in lithium hydroxide solutions, the powders produced were compressed into pellets and tested with cyclic voltammetry and the surface of the electrodes were analyzed with laser Raman spectroscopy. Results of the initial electrochemical testing showed good correlation with Nernstian behavior and exhibited quasi-reversible behaviour. The redox mechanism involves the breakdown of lithium ferrite into hematite, a hybrid lithiated-hematite oxide and lithium ions under the alkaline conditions tested. By comparing the equilibrium potential of the redox process with proposed reaction schemes and examining the reaction products using the laser Raman microprobe, the proposed redox mechanism could be verified. (author)

  13. Determination of antioxidant activity of spices and their active principles by differential pulse voltammetry.

    Science.gov (United States)

    Palma, Alberto; Ruiz Montoya, Mercedes; Arteaga, Jesús F; Rodríguez Mellado, Jose M

    2014-01-22

    The anodic oxidation of mercury in the presence of hydrogen peroxide in differential pulse voltammetry (DPV) was used to determine the antioxidant (AO) character of radical scavengers. Hydroperoxide radical is formed at the potentials of the oxidation peak on mercury electrodes, such radical reacting with the antioxidants in different extension. The parameter C10 (antioxidant concentration at which the peak area decreases by 10%) is used to measure the scavenging activity of the individual antioxidants. To establish the scavenging activity of antioxidant mixtures as a whole, the parameter, μ10 as the reverse of V10, V10 being the volume necessary to decrease the peak area in DPV by 10%, was selected. Higher μ10 values correspond to higher scavenging activity. The studies have been extended to aqueous extracts of some species. The results may be useful in explaining the effect of spices in vitro and in vivo studies.

  14. Imprinted Polymeric Film-Based Sensor for the Detection of Dopamine Using Cyclic Voltammetry

    Institute of Scientific and Technical Information of China (English)

    郭洪声; 何锡文; 李一峻

    2003-01-01

    The imprinted polymeric film was synthesized on the glass-carbon electrodes dlrectly. The response to the template molecule-dopamine and other molecules with similar structure was measured by cyclic voltammetry. The response of dopamine on imprinted electrode was much higher than that of other molecules,because of the existing of micro-cavities in polymeric rdm fitting with the size and shape of dopamine in the imprinted polymer.Experimental results showed that dopamlne can be enriched by the imprinted film, therefore increasing the sensitivity of the sensor. The imprinted film could also efface the interference of ascorbic acid, indicating that dopamine can be determined with a large excess of ascorbic acid.

  15. Cathodic stripping voltammetry of trace Mn(II) at carbon film electrodes.

    Science.gov (United States)

    Filipe, Olga M S; Brett, Christopher M A

    2003-12-04

    A sensitive voltammetric method is presented for the determination of tract levels of Mn (II) using carbon film electrodes fabricated from carbon resistors of 2 Omega. Determination of manganese was made by square wave cathodic stripping voltammetry (CSV), with deposition of manganese as manganese dioxide. Chronoamperometric experiments were made to study MnO(2) nucleation and growth. As a result, it was found to be necessary to perform electrode conditioning at a more positive potential to initiate MnO(2) nucleation. Under optimised conditions the detection limit obtained was 4 nM and the relative standard deviation for eight measurements of 0.22 nM was 5.3%. Interferences from various metal ions on the response CSV of Mn(II) were investigated, namely Cd(II), Ni(II), Cu(II), Cr(VI), Pb(II), Zn(II) and Fe(II). Application to environmental samples was demonstrated.

  16. Square Wave Voltammetry: An Alternative Technique to Determinate Piroxicam Release Profiles from Nanostructured Lipid Carriers.

    Science.gov (United States)

    Otarola, Jessica; Garrido, Mariano; Correa, N Mariano; Molina, Patricia G

    2016-08-04

    A new, simple, and fast electrochemical (EC) method has been developed to determine the release profile of piroxicam, a nonsteroidal anti-inflammatory drug, loaded in a drug delivery system based on nanostructured lipid carriers (NLCs). For the first time, the samples were analyzed by using square wave voltammetry, a sensitive EC technique. The piroxicam EC responses allow us to propose a model that explains the experimental results and to subsequently determine the amount of drug loaded into the NLCs formulation as a function of time. In vitro drug release studies showed prolonged drug release (up to 5 days), releasing 60 % of the incorporated drug. The proposed method is a promising and stable alternative for the study of different drug delivery systems.

  17. Duty to disclose what? Querying the putative obligation to return research results to participants.

    Science.gov (United States)

    Miller, F A; Christensen, R; Giacomini, M; Robert, J S

    2008-03-01

    Many research ethics guidelines now oblige researchers to offer research participants the results of research in which they participated. This practice is intended to uphold respect for persons and ensure that participants are not treated as mere means to an end. Yet some scholars have begun to question a generalised duty to disclose research results, highlighting the potential harms arising from disclosure and questioning the ethical justification for a duty to disclose, especially with respect to individual results. In support of this view, we argue that current rationales for a duty of disclosure do not form an adequate basis for an ethical imperative. We review policy guidance and scholarly commentary regarding the duty to communicate the results of biomedical, epidemiological and genetic research to research participants and show that there is wide variation in opinion regarding what should be disclosed and under what circumstance. Moreover, we argue that there is fundamental confusion about the notion of "research results," specifically regarding three core concepts: the distinction between aggregate and individual results, amongst different types of research, and across different degrees of result veracity. Even where policy guidance and scholarly commentary have been most forceful in support of an ethical imperative to disclose research results, ambiguity regarding what is to be disclosed confounds ethical action.

  18. Designing Summer Research Experiences for Teachers and Students That Promote Classroom Science Inquiry Projects and Produce Research Results

    Science.gov (United States)

    George, L. A.; Parra, J.; Rao, M.; Offerman, L.

    2007-12-01

    Research experiences for science teachers are an important mechanism for increasing classroom teachers' science content knowledge and facility with "real world" research processes. We have developed and implemented a summer scientific research and education workshop model for high school teachers and students which promotes classroom science inquiry projects and produces important research results supporting our overarching scientific agenda. The summer training includes development of a scientific research framework, design and implementation of preliminary studies, extensive field research and training in and access to instruments, measurement techniques and statistical tools. The development and writing of scientific papers is used to reinforce the scientific research process. Using these skills, participants collaborate with scientists to produce research quality data and analysis. Following the summer experience, teachers report increased incorporation of research inquiry in their classrooms and student participation in science fair projects. This workshop format was developed for an NSF Biocomplexity Research program focused on the interaction of urban climates, air quality and human response and can be easily adapted for other scientific research projects.

  19. Ascorbic Acid Determination in Commercial Fruit Juice Samples by Cyclic Voltammetry

    Science.gov (United States)

    Pisoschi, Aurelia Magdalena; Danet, Andrei Florin; Kalinowski, Slawomir

    2008-01-01

    A method was developed for assessing ascorbic acid concentration in commercial fruit juice by cyclic voltammetry. The anodic oxidation peak for ascorbic acid occurs at about 490 mV on a Pt disc working electrode (versus SCE). The influence of the potential sweep speed on the peak height was studied. The obtained calibration graph shows a linear dependence between peak height and ascorbic acid concentration in the domain (0.1–10 mmol·L−1). The equation of the calibration graph was y = 6.391x + 0.1903 (where y represents the value of intensity measured for the anodic peak height, expressed as μA and x the analyte concentration, as mmol·L−1, r2 = 0.9995, r.s.d. = 1.14%, n = 10, Cascorbic acid = 2 mmol·L−1). The developed method was applied to ascorbic acid assessment in fruit juice. The ascorbic acid content determined ranged from 0.83 to 1.67 mmol·L−1 for orange juice, from 0.58 to 1.93 mmol·L−1 for lemon juice, and from 0.46 to 1.84 mmol·L−1 for grapefruit juice. Different ascorbic acid concentrations (from standard solutions) were added to the analysed samples, the degree of recovery being comprised between 94.35% and 104%. Ascorbic acid determination results obtained by cyclic voltammetry were compared with those obtained by the volumetric method with dichlorophenol indophenol. The results obtained by the two methods were in good agreement. PMID:19343183

  20. Direct determination of molybdenum in seawater by adsorption cathodic stripping square-wave voltammetry.

    Science.gov (United States)

    Sun, Y C; Mierzwa, J; Lan, C R

    2000-06-30

    A reliable and very sensitive procedure for the determination of trace levels of molybdenum in seawater is proposed. The complex of molybdenum with 8-hydroxyquinoline (Oxine) is analyzed by cathodic stripping square-wave voltammetry based on the adsorption collection onto a hanging mercury drop electrode (HMDE). This procedure of molybdenum determination was found to be more favorable than differential pulse cathodic stripping voltammetry because of inherently faster scan rate and much better linearity obtained through the one-peak (instead of one-of-two peaks) calibration. The variation of polarographic peak and peak current with a pH, adsorption time, adsorption potential, and some instrumental parameters such as scan rate and pulse height were optimized. The alteration of polarographic wave and its likely mechanism are also discussed. The relationship between peak current and molybdenum concentration is linear up to 150 mug l(-1). Under the optimal analytical conditions, the determination limit of 0.5 mug l(-1) Mo was reached after 60 s of the stirred collection. The estimated detection limit is better than 0.1 mug l(-1) of Mo. The applicability of this method to analysis of seawater was assessed by the determination of molybdenum in two certified reference seawater samples (CASS-2 and NASS-2) and the comparison of the analytical results for real seawater samples (study on a vertical distribution of Mo in the seawater column) with the results obtained by Zeeman-corrected electrothermal atomization atomic absorption spectrometry (Zeeman ETAAS). A good agreement between two used methods of molybdenum determination was obtained.

  1. 76 FR 28625 - Sorghum Promotion, Research, and Information Program; State Referendum Results

    Science.gov (United States)

    2011-05-18

    ... Service 7 CFR 1221 Sorghum Promotion, Research, and Information Program; State Referendum Results AGENCY..., 2011, through February 28, 2011, have approved the continuation of the Sorghum Promotion, Research, and... Promotion, Research, and Information Act of 1996 (Act) (7 U.S.C. 7411-7425), the Department of...

  2. Increasing the trustworthiness of research results: the role of computers in qualitative text analysis

    Science.gov (United States)

    Lynne M. Westphal

    2000-01-01

    By using computer packages designed for qualitative data analysis a researcher can increase trustworthiness (i.e., validity and reliability) of conclusions drawn from qualitative research results. This paper examines trustworthiness issues and therole of computer software (QSR's NUD*IST) in the context of a current research project investigating the social...

  3. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry

    Directory of Open Access Journals (Sweden)

    Fatima AlZahra’a Alatraktchi

    2016-03-01

    Full Text Available Pyocyanin is a virulence factor uniquely produced by the pathogen Pseudomonas aeruginosa. The fast and selective detection of pyocyanin in clinical samples can reveal important information about the presence of this microorganism in patients. Electrochemical sensing of the redox-active pyocyanin is a route to directly quantify pyocyanin in real time and in situ in hospitals and clinics. The selective quantification of pyocyanin is, however, limited by other redox-active compounds existing in human fluids and by other metabolites produced by pathogenic bacteria. Here we present a direct selective method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between −1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58–0.82 V that is unaffected by other redox-active interferents. The linear quantification of pyocyanin has an R2 value of 0.991 across the clinically relevant concentration range of 2–100 µM. The proposed method was tested on human saliva showing a standard deviation of 2.5% ± 1% (n = 5 from the known added pyocyanin concentration to the samples. This inexpensive procedure is suggested for clinical use in monitoring the presence and state of P. aeruginosa infection in patients.

  4. In vivo histamine voltammetry in the mouse premammillary nucleus.

    Science.gov (United States)

    Samaranayake, Srimal; Abdalla, Aya; Robke, Rhiannon; Wood, Kevin M; Zeqja, Anisa; Hashemi, Parastoo

    2015-06-07

    Histamine plays a major role in the mediation of allergic reactions such as peripheral inflammation. This classical monoamine is also a neurotransmitter involved in the central nervous system but its role in this context is poorly understood. Studying histamine neurotransmission is important due to its implications in many neurological disorders. The sensitivity, selectivity and high temporal resolution of fast scan cyclic voltammetry (FSCV) offer many advantages for studying electroactive neurotransmitters. Histamine has previously been studied with FSCV; however, the lack of a robust Faradaic electrochemical signal makes it difficult to selectively identify histamine in complex media, as found in vivo. In this work, we optimize an electrochemical waveform that provides a stimulation-locked and unique electrochemical signal towards histamine. We describe in vitro waveform optimization and a novel in vivo physiological model for stimulating histamine release in the mouse premammillary nucleus via stimulation of the medial forebrain bundle. We demonstrate that a robust signal can be used to effectively identify histamine and characterize its in vivo kinetics.

  5. Cyclic voltammetry of apple fruits: Memristors in vivo.

    Science.gov (United States)

    Volkov, Alexander G; Nyasani, Eunice K; Tuckett, Clayton; Blockmon, Avery L; Reedus, Jada; Volkova, Maya I

    2016-12-01

    A memristor is a resistor with memory that exhibits a pinched hysteretic relationship in cyclic voltammetry. Recently, we have found memristors in the electrical circuitry of plants and seeds. There are no publications in literature about the possible existence of memristors and electrical differentiators in fruits. Here we found that the electrostimulation of Golden Delicious or Arkansas Black apple fruits by bipolar periodic waves induces hysteresis loops with pinched points in cyclic voltammograms at low frequencies between 0.1MHz and 1MHz. At high frequencies of 1kHz, the pinched hysteresis loop transforms to a non-pinched hysteresis loop instead of a single line I=V/R for ideal memristors because the amplitude of electrical current depends on capacitance of a fruit's tissue and electrodes, frequency and direction of scanning. Electrostimulation of electrical circuits in apple fruits by periodic voltage waves also induces electrotonic potential propagation due to cell-to-cell electrical coupling with electrical differentiators. A differentiator is an electrical circuit in which the output of the circuit is approximately directly proportional to the rate of change of the input. The information gained from electrostimulation can be used to elucidate and to observe electrochemical and electrophysiological properties of electrical circuits in fruits.

  6. Fully printed flexible and disposable wireless cyclic voltammetry tag.

    Science.gov (United States)

    Jung, Younsu; Park, Hyejin; Park, Jin-Ah; Noh, Jinsoo; Choi, Yunchang; Jung, Minhoon; Jung, Kyunghwan; Pyo, Myungho; Chen, Kevin; Javey, Ali; Cho, Gyoujin

    2015-01-29

    A disposable cyclic voltammetry (CV) tag is printed on a plastic film by integrating wireless power transmitter, polarized triangle wave generator, electrochemical cell and signage through a scalable gravure printing method. By proximity of 13.56 MHz RF reader, the printed CV tag generates 320 mHz of triangular sweep wave from +500 mV to -500 mV which enable to scan a printed electrochemical cell in the CV tag. By simply dropping any specimen solution on the electrochemical cell in the CV tag, the presence of solutes in the solution can be detected and shown on the signage of the CV tag in five sec. 10 mM of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) was used as a standard solute to prove the working concept of fully printed disposable wireless CV tag. Within five seconds, we can wirelessly diagnose the presence of TMPD in the solution using the CV tag in the proximity of the 13.56 MHz RF reader. This fully printed and wirelessly operated flexible CV tag is the first of its kind and marks the path for the utilization of inexpensive and disposable wireless electrochemical sensor systems for initial diagnose hazardous chemicals and biological molecules to improve public hygiene and health.

  7. Fast Selective Detection of Pyocyanin Using Cyclic Voltammetry.

    Science.gov (United States)

    Alatraktchi, Fatima AlZahra'a; Andersen, Sandra Breum; Johansen, Helle Krogh; Molin, Søren; Svendsen, Winnie E

    2016-03-19

    Pyocyanin is a virulence factor uniquely produced by the pathogen Pseudomonas aeruginosa. The fast and selective detection of pyocyanin in clinical samples can reveal important information about the presence of this microorganism in patients. Electrochemical sensing of the redox-active pyocyanin is a route to directly quantify pyocyanin in real time and in situ in hospitals and clinics. The selective quantification of pyocyanin is, however, limited by other redox-active compounds existing in human fluids and by other metabolites produced by pathogenic bacteria. Here we present a direct selective method to detect pyocyanin in a complex electroactive environment using commercially available electrodes. It is shown that cyclic voltammetry measurements between -1.0 V to 1.0 V reveal a potential detection window of pyocyanin of 0.58-0.82 V that is unaffected by other redox-active interferents. The linear quantification of pyocyanin has an R² value of 0.991 across the clinically relevant concentration range of 2-100 µM. The proposed method was tested on human saliva showing a standard deviation of 2.5% ± 1% (n = 5) from the known added pyocyanin concentration to the samples. This inexpensive procedure is suggested for clinical use in monitoring the presence and state of P. aeruginosa infection in patients.

  8. Outline of the safety research results, in the power reactor field, fiscal year 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-11-01

    The Power Reactor and Nuclear Fuel Development Corporation (PNC) has promoted the safety research in fiscal year of 1996 according to the Fundamental Research on Safety Research (fiscal year 1996 to 2000) prepared on March, 1996. Here is described on the research results in fiscal year 1996, the first year of the 5 years programme, and whole outline of the fundamental research on safety research, on the power reactor field (whole problems on the new nuclear converter and the fast breeder reactor field and problems relating to the power reactor in the safety for earthquake and probability theoretical safety evaluation field). (G.K.)

  9. Application of thin-shielded mercury microelectrodes in anodic stripping voltammetry.

    Science.gov (United States)

    Daniele, Salvatore; Bragato, Carlo; Baldo, M Antonietta; Ciani, Ilenia

    2008-10-19

    The performance in anodic stripping voltammetry (ASV) of hemispherical mercury microelectrodes, fabricated by electrodeposition of liquid mercury on the surface of Pt microdisks which were surrounded by a rather thick or thin insulating shield, was compared. The Pt microdisks were produced by sealing a wire of 25 microm diameter into a glass capillary, and by coating the cylindrical length of the Pt wire with a cathodic electrophoretic paint. The ratio of the overall tip radius b, to the basal radius of the electrode a, so-called RG=b/a, was equal to 110+/-10 and 1.52+/-0.01 for the thick- and thin-shielded microdisk, respectively. The mercury microelectrodes were characterized by cyclic voltammetry at 1 mVs(-1), in 1mM Ru(NH(3))(6)(3+) aqueous solution. The steady-state voltammogram recorded with the thin-shielded mercury microelectrode displayed less hysteresis, while the steady-state current was about 30% higher than that of the thicker one. This was a consequence of the additional flux due to diffusion from behind the plane of the electrode. The flux enhancement, which was operative at the thin-shielded mercury microelectrode during the deposition step in the ASV experiments, allowed recording stripping peaks for Cd and Pb, which resulted about 32% larger than those recorded at the thicker shielded mercury microelectrode, under same experimental conditions. The usefulness of the thin-shielded mercury microelectrode for ASV measurements in real samples was verified by determining the content of heavy metal ions released in the pore water (pH 4.5) of a soil slurry.

  10. Characterizing researchers by strategies used for retaining minority participants: results of a national survey.

    Science.gov (United States)

    Butler, James; Quinn, Sandra C; Fryer, Craig S; Garza, Mary A; Kim, Kevin H; Thomas, Stephen B

    2013-09-01

    Limited attention has been given to the optimal strategies for retaining racial and ethnic minorities within studies and during the follow-up period. High attrition limits the interpretation of results and reduces the ability to translate findings into successful interventions. This study examined the retention strategies used by researchers when retaining minorities in research studies. From May to August 2010, we conducted an online survey with researchers (principal investigators, research staff, and IRB members) and examined their use of seven commonly used retention strategies. The number and type of retention strategies used, how these strategies differ by researcher type, and other characteristics (e.g., funding) were explored. We identified three clusters of researchers: comprehensive retention strategy researchers - utilized the greatest number of retention strategies; moderate retention strategy researchers - utilized an average number of retention strategies; and limited retention strategy researchers - utilized the least number of retention strategies. The comprehensive and moderate retention strategy researchers were more likely than the limited retention strategy researchers to conduct health outcomes research, work with a community advisory board, hire minority staff, use steps at a higher rate to overcome retention barriers, develop new partnerships with the minority community, modify study materials for the minority population, and allow staff to work flexible schedules. This study is a novel effort to characterize researchers, without implying a value judgment, according to their use of specific retention strategies. It provides critical information for conducting future research to determine the effectiveness of using a combination of retention strategies.

  11. Critical appraisal of quantitative PCR results in colorectal cancer research: can we rely on published qPCR results?

    Science.gov (United States)

    Dijkstra, J R; van Kempen, L C; Nagtegaal, I D; Bustin, S A

    2014-06-01

    The use of real-time quantitative polymerase chain reaction (qPCR) in cancer research has become ubiquitous. The relative simplicity of qPCR experiments, which deliver fast and cost-effective results, means that each year an increasing number of papers utilizing this technique are being published. But how reliable are the published results? Since the validity of gene expression data is greatly dependent on appropriate normalisation to compensate for sample-to-sample and run-to-run variation, we have evaluated the adequacy of normalisation procedures in qPCR-based experiments. Consequently, we assessed all colorectal cancer publications that made use of qPCR from 2006 until August 2013 for the number of reference genes used and whether they had been validated. Using even these minimal evaluation criteria, the validity of only three percent (6/179) of the publications can be adequately assessed. We describe common errors, and conclude that the current state of reporting on qPCR in colorectal cancer research is disquieting. Extrapolated to the study of cancer in general, it is clear that the majority of studies using qPCR cannot be reliably assessed and that at best, the results of these studies may or may not be valid and at worst, pervasive incorrect normalisation is resulting in the wholesale publication of incorrect conclusions. This survey demonstrates that the existence of guidelines, such as MIQE, is necessary but not sufficient to address this problem and suggests that the scientific community should examine its responsibility and be aware of the implications of these findings for current and future research.

  12. Commenting on Research Results in Applied Linguistics and Education: A Comparative Genre-Based Investigation

    Science.gov (United States)

    Lim, Jason Miin-Hwa

    2010-01-01

    As university students are frequently given the tasks of writing research reports to fulfil their respective programme requirements, teaching novice writers to present the results of their reports understandably constitutes an essential component of English lessons at tertiary level. While past research has shown that results are consistently…

  13. Building America Residential System Research Results: Achieving 30% Whole House Energy Savings Level in Cold Climates

    Energy Technology Data Exchange (ETDEWEB)

    Building Industry Research Alliance (BIRA); Building Science Consortium (BSC); Consortium for Advanced Residential Buildings (CARB); Florida Solar Energy Center (FSEC); IBACOS; National Renewable Energy Laboratory (NREL)

    2006-08-01

    The Building America program conducts the system research required to reduce risks associated with the design and construction of homes that use an average of 30% to 90% less total energy for all residential energy uses than the Building America Research Benchmark, including research on homes that will use zero net energy on annual basis. To measure the program's progress, annual research milestones have been established for five major climate regions in the United States. The system research activities required to reach each milestone take from 3 to 5 years to complete and include research in individual test houses, studies in pre-production prototypes, and research studies with lead builders that provide early examples that the specified energy savings level can be successfully achieved on a production basis. This report summarizes research results for the 30% energy savings level and demonstrates that lead builders can successfully provide 30% homes in Cold Climates on a cost-neutral basis.

  14. Researchers' experience with project management in health and medical research: Results from a post-project review

    Directory of Open Access Journals (Sweden)

    Elliott Elizabeth J

    2011-06-01

    Full Text Available Abstract Background Project management is widely used to deliver projects on time, within budget and of defined quality. However, there is little published information describing its use in managing health and medical research projects. We used project management in the Alcohol and Pregnancy Project (2006-2008 http://www.ichr.uwa.edu.au/alcoholandpregnancy and in this paper report researchers' opinions on project management and whether it made a difference to the project. Methods A national interdisciplinary group of 20 researchers, one of whom was the project manager, formed the Steering Committee for the project. We used project management to ensure project outputs and outcomes were achieved and all aspects of the project were planned, implemented, monitored and controlled. Sixteen of the researchers were asked to complete a self administered questionnaire for a post-project review. Results The project was delivered according to the project protocol within the allocated budget and time frame. Fifteen researchers (93.8% completed a questionnaire. They reported that project management increased the effectiveness of the project, communication, teamwork, and application of the interdisciplinary group of researchers' expertise. They would recommend this type of project management for future projects. Conclusions Our post-project review showed that researchers comprehensively endorsed project management in the Alcohol and Pregnancy Project and agreed that project management had contributed substantially to the research. In future, we will project manage new projects and conduct post-project reviews. The results will be used to encourage continuous learning and continuous improvement of project management, and provide greater transparency and accountability of health and medical research. The use of project management can benefit both management and scientific outcomes of health and medical research projects.

  15. Researchers' experience with project management in health and medical research: Results from a post-project review

    Science.gov (United States)

    2011-01-01

    Background Project management is widely used to deliver projects on time, within budget and of defined quality. However, there is little published information describing its use in managing health and medical research projects. We used project management in the Alcohol and Pregnancy Project (2006-2008) http://www.ichr.uwa.edu.au/alcoholandpregnancy and in this paper report researchers' opinions on project management and whether it made a difference to the project. Methods A national interdisciplinary group of 20 researchers, one of whom was the project manager, formed the Steering Committee for the project. We used project management to ensure project outputs and outcomes were achieved and all aspects of the project were planned, implemented, monitored and controlled. Sixteen of the researchers were asked to complete a self administered questionnaire for a post-project review. Results The project was delivered according to the project protocol within the allocated budget and time frame. Fifteen researchers (93.8%) completed a questionnaire. They reported that project management increased the effectiveness of the project, communication, teamwork, and application of the interdisciplinary group of researchers' expertise. They would recommend this type of project management for future projects. Conclusions Our post-project review showed that researchers comprehensively endorsed project management in the Alcohol and Pregnancy Project and agreed that project management had contributed substantially to the research. In future, we will project manage new projects and conduct post-project reviews. The results will be used to encourage continuous learning and continuous improvement of project management, and provide greater transparency and accountability of health and medical research. The use of project management can benefit both management and scientific outcomes of health and medical research projects. PMID:21635721

  16. Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid.

    Science.gov (United States)

    Yang, Guangming; Li, Ling; Jiang, Jinhe; Yang, Yunhui

    2012-08-01

    Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02×10(-7)-5.23×10(-4) mol L(-1) and 1.43×10(-7)-4.64×10(-4) mol L(-1), the detection limits were 1.12×10(-8) mol L(-1) and 2.24×10(-8) mol L(-1), respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Method of evaluation of electron transfer kinetics of a surface-confined redox system by means of Fourier transformed square wave voltammetry.

    Science.gov (United States)

    Huang, Xinjian; Wang, Lishi; Liao, Shijun

    2008-07-15

    A new form of Fourier transformed square wave voltammetry (FT-SWV) is proposed to simplify and accelerate the electron transfer kinetics evaluation procedures for surface-confined redox systems. Even harmonic frequencies, which are derived from the nonlinear Faradaic response, will arise in the power spectrum after Fourier transformation of the current response of FT-SWV. The profile of the even harmonic power spectra is bell-shaped and shows a maximum at a certain frequency. The electrode kinetics-dependent maximum and the corresponding frequency are equivalent to the so-called "quasi-reversible maximum" and "critical frequency" (fmax) in traditional SWV, respectively. The critical frequency can be regarded as a frequency that is synchronized to the electron transfer rate constant (k(0)). As a result, it can serve as a probe of k(0) by means of a very simple equation, k(0) = kmax fmax. Compared with traditional cyclic voltammetry, square wave voltammetry, alternating current voltammetry, and several other voltammetric techniques, this method exhibits great advantages for its simplicity, rapidity, and sensitivity.

  18. Electrolyte Effects on the Cyclic Voltammetry of TCNQ (Tetracyanoquinodimethane) and TCNE (Tetracyanoethylene).

    Science.gov (United States)

    1986-07-30

    to form two radical anions. In this note we report a study by cyclic voltammetry of the reductions of TCNQ and TCNE to their radical anions and dianions at platinum and glassy carbon electrodes in acetonitrile.

  19. Theory of linear sweep voltammetry with diffuse charge: unsupported electrolytes, thin films, and leaky membranes

    CERN Document Server

    Yan, David; Pugh, Mary C; Dawson, Francis P

    2016-01-01

    Linear sweep and cyclic voltammetry techniques are important tools for electrochemists and have a variety of applications in engineering. Voltammetry has classically been treated with the Randles-Sevcik equation, which assumes an electroneutral supported electrolyte. No general theory of linear-sweep voltammetry is available, however, for unsupported electrolytes and for other situations where diffuse charge effects play a role. In this paper, we provide a historical review of previous models and experiments and present a comprehensive mathematical theory of voltammetry in electrochemical cells with diffuse charge. We solve the time-dependent Poisson-Nernst-Planck (PNP) equations with generalized Frumkin-Butler-Volmer (FBV) boundary conditions, and show theoretical and simulated current-voltage curves for liquid and solid thin films, cells with blocking electrodes, and membranes with fixed background charge. The full range of dimensionless parameters is considered, including the dimensionless Debye screening ...

  20. Voltammetry and In Situ Scanning Tunneling Microscopy of Cytochrome c Nitrite Reductase on Au(111)-Electrodes

    DEFF Research Database (Denmark)

    Gwyer, James; Zhang, Jingdong; Butt, Julea

    2006-01-01

    of the density and orientational distribution of NrfA molecules are disclosed. The submonolayer coverage resolved by in situ STM is readily reconciled with the failure to detect nonturnover signals in cyclic voltammetry of the NrfA films. The molecular structures show a range of lateral dimensions...... a direct approach to correlate electrocatalytic and molecular properties of the protein layer, a long-standing issue in protein film voltammetry....

  1. General practitioners' attitudes towards research in primary care: qualitative results of a cross sectional study

    Science.gov (United States)

    Rosemann, Thomas; Szecsenyi, Joachim

    2004-01-01

    Background Research in General Practice requires the participation of General practitioners (GPs). In Germany there is little tradition of research in this field, and GPs are not used to be participants in research. Little is known about German GPs attitudes towards research. Therefore the aim of our study was to assess the willingness of German General Practitioners to participate in primary care research and their attitude towards research in general practice. The results should enable a more successful approach to GPs in further studies. Methods Cross sectional study using semi-structured interviews with a random sample of 76 General Practitioners who participate in the teaching of medical students at the University of Heidelberg. Results Despite little experience, over 85 % of GPs appreciated research in their field. Important reasons for scepticism about research were the gap between theoretical research and practical work of GPs and the domination of research by specialists. Main barriers for participation are clinical workload, administrative overload and the newly introduced Disease Management Programs. The highest motivation for GPs to participate in research emanates from the will to substantiate their quality of care with solid research data. Conclusions Financial incentives and personal support e.g. with study nurses are certainly necessary to establish a research culture and to overcome main barriers against participation. The most successful approach to motivate GPs to participate is to convince them that research documents their quality of care. This data may reflect the facts on which the financial resources are provided in the future health care system. PMID:15613246

  2. Research Priorities in the Field of Patient Safety in Iran: Results of a Delphi Study.

    Science.gov (United States)

    Ravaghi, Hamid; Sajadi, Haniye Sadat

    2015-06-12

    There is inadequate evidence to direct and support patient safety practice. Therefore, identifying research priorities in this field is relevant for many stakeholders. This study, which was built on the World Health Organization work, aimed to identify and prioritize research topics for patient safety in Iran. A 3-round Modified Delphi process was used. We purposefully recruited a panel of 45 policy makers, planners, health care managers and staff, and academic members with experience or expertise in patient safety research. A review of the literature was used to develop the first questionnaire, including 24 research topics. Respondents were asked to rate their agreement with each research topic and propose new topics. Based on the results of round 1, the second questionnaire was developed and the respondents were requested to rate 45 research topics and also put similar research topics in the same groups. Given the responses of round 2, the third questionnaire including a list of 45 research priorities categorized in 4 groups was developed. Respondents were asked to reflect their opinions. Content analysis was used to analyze round 1 data and descriptive statistics for round 2 and round 3 data. Forty-five identified research topics in round 1 prioritized and grouped in subsequent rounds. Among 4 research groups, the extent and epidemiology threatening patient safety group received the highest priority; and among research topics, adverse drug events and its epidemiology were the top-ranked research priorities. In addition to the priorities identified in previous work, more research priorities that reflect important and needed issue related to patient safety, especially in Iran, were recognized. This priority research list, which most stakeholders agree with it, can serve as a blueprint for patient safety research.

  3. Results of a research study on the impact of active daylighting on operating results of a retail business

    Energy Technology Data Exchange (ETDEWEB)

    1993-01-01

    In preliminary evaluations of So-Luminaire's (SI) product in 1985 and 1986, DOE concluded that it warranted further research and evaluation and was worthy of receiving governmental financial and structural support therefor. SI, along with Safeway, had known intuitively that the So-Luminaire systems which had been previously installed in several of their Phoenix-area stores had resulted in a marked reduction in electrical energy consumption. However, a definitive determination of energy savings had been utilized in previous installations. Further, SI and Safeway both hypothesized that the high quality of natural light provided by these systems displayed goods to greater advantage and contributed to an overall increase in store sales, all other factors being held constant. A study to attempt to objectively determine these two presumed benefits of active daylighting in a commercial application was begun.

  4. Results of a research study on the impact of active daylighting on operating results of a retail business. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1993-04-01

    In preliminary evaluations of So-Luminaire`s (SI) product in 1985 and 1986, DOE concluded that it warranted further research and evaluation and was worthy of receiving governmental financial and structural support therefor. SI, along with Safeway, had known intuitively that the So-Luminaire systems which had been previously installed in several of their Phoenix-area stores had resulted in a marked reduction in electrical energy consumption. However, a definitive determination of energy savings had been utilized in previous installations. Further, SI and Safeway both hypothesized that the high quality of natural light provided by these systems displayed goods to greater advantage and contributed to an overall increase in store sales, all other factors being held constant. A study to attempt to objectively determine these two presumed benefits of active daylighting in a commercial application was begun.

  5. Results of a transparent expert consultation on patient and public involvement in palliative care research

    Science.gov (United States)

    Daveson, Barbara A; de Wolf-Linder, Susanne; Witt, Jana; Newson, Kirstie; Morris, Carolyn; Higginson, Irene J; Evans, Catherine J

    2015-01-01

    Background: Support and evidence for patient, unpaid caregiver and public involvement in research (user involvement) are growing. Consensus on how best to involve users in palliative care research is lacking. Aim: To determine an optimal user-involvement model for palliative care research. Design: We hosted a consultation workshop using expert presentations, discussion and nominal group technique to generate recommendations and consensus on agreement of importance. A total of 35 users and 32 researchers were approached to attend the workshop, which included break-out groups and a ranking exercise. Descriptive statistical analysis to establish consensus and highlight divergence was applied. Qualitative analysis of discussions was completed to aid interpretation of findings. Setting/participants: Participants involved in palliative care research were invited to a global research institute, UK. Results: A total of 12 users and 5 researchers participated. Users wanted their involvement to be more visible, including during dissemination, with a greater emphasis on the difference their involvement makes. Researchers wanted to improve productivity, relevance and quality through involvement. Users and researchers agreed that an optimal model should consist of (a) early involvement to ensure meaningful involvement and impact and (b) diverse virtual and face-to-face involvement methods to ensure flexibility. Conclusion: For involvement in palliative care research to succeed, early and flexible involvement is required. Researchers should advertise opportunities for involvement and promote impact of involvement via dissemination plans. Users should prioritise adding value to research through enhancing productivity, quality and relevance. More research is needed not only to inform implementation and ensure effectiveness but also to investigate the cost-effectiveness of involvement in palliative care research. PMID:25931336

  6. Wireless fast-scan cyclic voltammetry to monitor adenosine in patients with essential tremor during deep brain stimulation.

    Science.gov (United States)

    Chang, Su-Youne; Kim, Inyong; Marsh, Michael P; Jang, Dong Pyo; Hwang, Sun-Chul; Van Gompel, Jamie J; Goerss, Stephan J; Kimble, Christopher J; Bennet, Kevin E; Garris, Paul A; Blaha, Charles D; Lee, Kendall H

    2012-08-01

    Essential tremor is often markedly reduced during deep brain stimulation simply by implanting the stimulating electrode before activating neurostimulation. Referred to as the microthalamotomy effect, the mechanisms of this unexpected consequence are thought to be related to microlesioning targeted brain tissue, that is, a microscopic version of tissue ablation in thalamotomy. An alternate possibility is that implanting the electrode induces immediate neurochemical release. Herein, we report the experiment performing with real-time fast-scan cyclic voltammetry to quantify neurotransmitter concentrations in human subjects with essential tremor during deep brain stimulation. The results show that the microthalamotomy effect is accompanied by local neurochemical changes, including adenosine release.

  7. Application of normal pulse voltammetry to the kinetic study of formic acid oxidation on a carbon supported Pd electrocatalyst

    Science.gov (United States)

    Wang, Yujiao; Wu, Xiaochen; Wu, Bing; Gao, Ying

    The kinetic parameters of formic acid oxidation on a carbon supported Pd electrode, such as the charge transfer coefficient (α) and apparent diffusion coefficient (D) are obtained by applying the technique of normal pulse voltammetry. The standard rate constant (k 0) of formic acid oxidation on a Pd/C electrode is estimated. The results show that formic acid oxidation is more sensitive to temperature at relatively high potential because the activation energy is significantly increased as the potential rose above 0.6 V.

  8. Resolution of quaternary mixtures of cadaverine, histamine, putrescine and tyramine by the square wave voltammetry and partial least squares method.

    Science.gov (United States)

    Henao-Escobar, W; Domínguez-Renedo, O; Alonso-Lomillo, M A; Arcos-Martínez, M J

    2015-10-01

    This work presents the simultaneous determination of cadaverine, histamine, putrescine and tyramine by square wave voltammetry using a boron-doped diamond electrode. A multivariate calibration method based on partial least square regressions has allowed the resolution of the very high overlapped voltammetric signals obtained for the analyzed biogenic amines. Prediction errors lower than 9% have been obtained when concentration of quaternary mixtures were calculated. The developed procedure has been applied in the analysis of ham samples, which results are in good agreement with those obtained using the standard HPLC method.

  9. Determination of Soil Base—Soluble Se by Anodic Stripping Voltammetry with Aurum Thin—Film Electrode

    Institute of Scientific and Technical Information of China (English)

    YANGZENG; HEYING; 等

    1994-01-01

    Determination of soil Se by anodic stripping voltammetry(ASV) with aurum thin-film electrode(ATFE)overcomes the interference of gold peak with selenium peak,and thus has a higher sensitivity with the miniumum detectable concentration being 0.017μg/mL,the standard deviation of the measured results leww than 0.012μg/g,the coefficient of variation lwoer than 10% ,and the recovery rate between 86% to 103%.Besides the measurement conditions,the digestion of soil sample was also studied in detail.

  10. RESULTS OF RESEARCH OF AIR POLLUTION BY AUTOMOBILE TRANSPORT IN THE STREETS OF KHARKIV

    Directory of Open Access Journals (Sweden)

    Lezhneva, E.

    2013-06-01

    Full Text Available Results of the research of the atmospheric air of residential area roadside territory at functioning of motor transport are presented. Architectural and planning activities to improve the environmental performance of the local area of Kharkiv are offered.

  11. Iron organic speciation determination in rainwater using cathodic stripping voltammetry.

    Science.gov (United States)

    Cheize, Marie; Sarthou, Géraldine; Croot, Peter L; Bucciarelli, Eva; Baudoux, Anne-Claire; Baker, Alex R

    2012-07-29

    A sensitive method using Competitive Ligand Exchange-Adsorptive Cathodic Stripping Voltammetry (CLE-ACSV) has been developed to determine for the first time iron (Fe) organic speciation in rainwater over the typical natural range of pH. We have adapted techniques previously developed in other natural waters to rainwater samples, using the competing ligand 1-nitroso-2-naphthol (NN). The blank was equal to 0.17±0.05 nM (n=14) and the detection limit (DL) for labile Fe was 0.15 nM which is 10-70 times lower than that of previously published methods. The conditional stability constant for NN under rainwater conditions was calibrated over the pH range 5.52-6.20 through competition with ethylenediaminetetraacetic acid (EDTA). The calculated value of the logarithm of β'(Fe(3+)(NN)(3)) increased linearly with increasing pH according to log β'(Fe(3+)(NN)(3)) (salinity=2.9, T=20 °C). The validation of the method was carried out using desferrioxamine mesylate B (DFOB) as a natural model ligand for Fe. Adequate detection windows were defined to detect this class of ligands in rainwater with 40 μM of NN from pH 5.52 to 6.20. The concentration of Fe-complexing natural ligands was determined for the first time in three unfiltered and one filtered rainwater samples. Organic Fe-complexing ligand concentrations varied from 104.2±4.1 nM equivalent of Fe(III) to 336.2±19.0 nM equivalent of Fe(III) and the logarithm of the conditional stability constants, with respect to Fe(3+), varied from 21.1±0.2 to 22.8±0.3. This method will provide important data for improving our understanding of the role of wet deposition in the biogeochemical cycling of iron. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. International Research Results and Accomplishments From the International Space Station - A New Compilation

    Science.gov (United States)

    Ruttley, Tara; Robinson, Julie A.; Tate-Brown, Judy; Perkins, Nekisha; Cohen, Luchino; Marcil, Isabelle; Heppener, Marc; Hatton, Jason; Tasaki, Kazuyuki; Umemura, Sayaka; Karabadzhak, Georgy; Sorokin, Igor V.; Cotronei, Vittorio; Jean, Sabbagh

    2016-01-01

    In 2016, the International Space Station (ISS) partnership published the first-ever compilation of international ISS research publications resulting from research performed on the ISS through 2011 (Expeditions 0 through 30). International Space Station Research Accomplishments: An Analysis of Results. From 2000-2011 is a collection of over 1,200 journal publications that describe ISS research in the areas of biology and biotechnology; Earth and space science; educational activities and outreach; human research; physical sciences; technology development and demonstration; and, results from ISS operations. This paper will summarize the ISS results publications obtained through 2011 on behalf of the ISS Program Science Forum that is made up of senior science representatives across the international partnership. NASA's ISS Program Science office maintains an online experiment database (www.nasa.gov/iss- science) that tracks and communicates ISS research activities across the entire ISS partnership, and it is continuously updated by cooperation and linking with the results tracking activities of each partner. It captures ISS experiment summaries and results and includes citations to the journals, conference proceedings, and patents as they become available. This content is obtained through extensive and regular journal and patent database searches, and input provided by the ISS international partners ISS scientists themselves. The International Space Station Research Accomplishments: An Analysis of Results From 2000-2011 is a testament to the research that was underway even as the ISS laboratory was being built. It rejects the scientific knowledge gained from ISS research, and how it impact the fields of science in both space and traditional science disciplines on Earth. Now, during a time when utilization is at its busiest, and with extension of the ISS through at least 2024, the ISS partners work together to track the accomplishments and the new knowledge gained in a

  13. Returning a Research Participant's Genomic Results to Relatives: Analysis and Recommendations.

    Science.gov (United States)

    Wolf, Susan M; Branum, Rebecca; Koenig, Barbara A; Petersen, Gloria M; Berry, Susan A; Beskow, Laura M; Daly, Mary B; Fernandez, Conrad V; Green, Robert C; LeRoy, Bonnie S; Lindor, Noralane M; O'Rourke, P Pearl; Breitkopf, Carmen Radecki; Rothstein, Mark A; Van Ness, Brian; Wilfond, Benjamin S

    2015-01-01

    Genomic research results and incidental findings with health implications for a research participant are of potential interest not only to the participant, but also to the participant's family. Yet investigators lack guidance on return of results to relatives, including after the participant's death. In this paper, a national working group offers consensus analysis and recommendations, including an ethical framework to guide investigators in managing this challenging issue, before and after the participant's death.

  14. Commenting on Results in Published Research Articles and Masters Dissertations in Language Teaching

    Science.gov (United States)

    Basturkmen, Helen

    2009-01-01

    This study investigates the ways writers comment on the results of their research. Making claims in the form of Commenting on Results is a key move in discussion of results sections. Using data drawn from published journal articles and master dissertations in Language Teaching, the study investigates how published academics and students writing…

  15. Genomic research with human samples. Points of view from scientists and research subjects about disclosure of results and risks of genomic research. Ethical and empirical approach.

    Science.gov (United States)

    Valle Mansilla, José Ignacio

    2011-01-01

    Biomedical researchers often now ask subjects to donate samples to be deposited in biobanks. This is not only of interest to researchers, patients and society as a whole can benefit from the improvements in diagnosis, treatment, and prevention that the advent of genomic medicine portends. However, there is a growing debate regarding the social and ethical implications of creating biobanks and using stored human tissue samples for genomic research. Our aim was to identify factors related to both scientists and patients' preferences regarding the sort of information to convey to subjects about the results of the study and the risks related to genomic research. The method used was a survey addressed to 204 scientists and 279 donors from the U.S. and Spain. In this sample, researchers had already published genomic epidemiology studies; and research subjects had actually volunteered to donate a human sample for genomic research. Concerning the results, patients supported more frequently than scientists their right to know individual results from future genomic research. These differences were statistically significant after adjusting by the opportunity to receive genetic research results from the research they had previously participated and their perception of risks regarding genetic information compared to other clinical data. A slight majority of researchers supported informing participants about individual genomic results only if the reliability and clinical validity of the information had been established. Men were more likely than women to believe that patients should be informed of research results even if these conditions were not met. Also among patients, almost half of them would always prefer to be informed about individual results from future genomic research. The three main factors associated to a higher support of a non-limited access to individual results were: being from the US, having previously been offered individual information and considering

  16. Outline of results of safety research (in nuclear fuel cycle field in fiscal year 1996)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The safety research in Power Reactor and Nuclear Fuel Development Corporation in fiscal year 1996 has been carried out based on the basic plan of safety research (from fiscal year 1996 to 2000) which was decided in March, 1996. In this report, on nuclear fuel cycle field, namely all the subjects in the fields of nuclear fuel facilities, environmental radioactivity and waste disposal, and the subjects related to nuclear fuel facilities among the fields of aseismatic and probabilistic safety assessments, the results of research in fiscal year 1996, the first year of the 5-year project, are summarized together with the outline of the basic plan of safety research. The basic policy, objective and system for promotion of the safety research are described. The objectives of the safety research are the advancement of safety technology, the safety of facilities, stable operation techniques, the safety design and the evaluation techniques of next generation facilities, and the support of transferring nuclear fuel cycle to private businesses. The objects of the research are uranium enrichment, fuel fabrication and reprocessing, and waste treatment and storage. 52 investigation papers of the results of the safety research in nuclear fuel cycle field in fiscal year 1996 are collected in this report. (K.I.)

  17. Robotic voltammetry with carbon nanotube-based sensors: a superb blend for convenient high-quality antimicrobial trace analysis

    Science.gov (United States)

    Theanponkrang, Somjai; Suginta, Wipa; Weingart, Helge; Winterhalter, Mathias; Schulte, Albert

    2015-01-01

    A new automated pharmacoanalytical technique for convenient quantification of redox-active antibiotics has been established by combining the benefits of a carbon nanotube (CNT) sensor modification with electrocatalytic activity for analyte detection with the merits of a robotic electrochemical device that is capable of sequential nonmanual sample measurements in 24-well microtiter plates. Norfloxacin (NFX) and ciprofloxacin (CFX), two standard fluoroquinolone antibiotics, were used in automated calibration measurements by differential pulse voltammetry (DPV) and accomplished were linear ranges of 1–10 μM and 2–100 μM for NFX and CFX, respectively. The lowest detectable levels were estimated to be 0.3±0.1 μM (n=7) for NFX and 1.6±0.1 μM (n=7) for CFX. In standard solutions or tablet samples of known content, both analytes could be quantified with the robotic DPV microtiter plate assay, with recoveries within ±4% of 100%. And recoveries were as good when NFX was evaluated in human serum samples with added NFX. The use of simple instrumentation, convenience in execution, and high effectiveness in analyte quantitation suggest the merger between automated microtiter plate voltammetry and CNT-supported electrochemical drug detection as a novel methodology for antibiotic testing in pharmaceutical and clinical research and quality control laboratories. PMID:25670899

  18. Predicting Results of the Research Excellence Framework using departmental h-Index

    CERN Document Server

    Mryglod, Olesya; Holovatch, Yurij; Berche, Bertrand

    2014-01-01

    We compare estimates for past institutional research performances coming from two bibliometric indicators to the results of the UK's Research Assessment Exercise which last took place in 2008. We demonstrate that a version of the departmental h-index is better correlated with the actual results of that peer-review exercise than a competing metric known as the normalised citation-based indicator. We then determine the corresponding h-indices for 2008-2013, the period examined in the UK's Research Excellence Framework (REF) 2014. We place herewith the resulting predictions on the arXiv in advance of the REF results being published (December 2014). These may be considered as unbiased predictions of relative performances in that exercise. We will revisit this paper after the REF results are available and comment on the reliability or otherwise of these bibliometrics as compared with peer review.

  19. Quality of research results in agro-economy by data mining

    Directory of Open Access Journals (Sweden)

    Vukelić Gordana

    2015-01-01

    Full Text Available Data Mining (DM through data in agroeconomy is a scientific method that enables researchers not to go through set research scenarioes that are predetermined assumptions and hypotheses on the basis of insignificant atributes. On the contrary, by data mining detection of these atributes is made possible, in general, those hiden facts that enable setting a hypothesis. The DM method does this by an iterative way, including key atributes and factors and their influence on the quality of agro-resources. The research was conducted on a random sample, by analyzing the quality of eggs. The research subject is the posibility of classifying and predicting significant variablesatributes that determine the level of egg quality. The research starts from the use of Data Mining, as an area of machine studies, which significantly helps researchers in optimizing research. The applied methodology during research includes analyticalsintetic procedures and methods of Data Mining, with a special focus on using Supervised linear discrimination analysis and the Decision Tree. The results indicate significant posibilities of using DM as an additional analytical procedure in performing agroresearch and it can be concluded that it contributes to an improvement in effectiveness and validity of process in performing these researches.

  20. Disseminating and implementing the results of back pain research in primary care.

    Science.gov (United States)

    van Tulder, Maurits W; Croft, Peter R; van Splunteren, Peter; Miedema, Harald S; Underwood, Martin R; Hendriks, Henricus J M; Wyatt, Mary E; Borkan, Jeffrey M

    2002-03-01

    Description of a workshop entitled "Implementation and Dissemination: Getting Research into Practice," that was held at the Fourth International Forum on Low Back Pain Research in Primary Care, in Israel in March 2000. A gap exists between research endeavors and the dissemination and implementation of new research findings. To describe the outcomes of a workshop on implementation and dissemination of research findings. The Fourth International Forum on Low Back Pain Research in Primary Care aimed to encourage open discussion and consensus building among leading experts in the field, and to develop a research agenda. The workshop on implementation and dissemination focused on issues surrounding the gap between research results and actual practice. These issues were introduced by several presentations. The broad conclusions of the subsequent debate are summarized in this paper as a series of responses to key questions: 1) who should do the implementation?, 2) what should researchers do to help implementation?, 3) what are the key outcomes?, and 4) what are important ingredients for successful implementation? There was consensus about the importance of implementation of research findings, about the ineffectiveness of merely publishing or disseminating research findings, and about the need for prospective randomized trials evaluating the cost-effectiveness of different implementation strategies. The majority view is that the health provider professions and the professional bodies are the central organizations to implement guidelines, rather than the researchers themselves. Success in getting guidelines or research results into practice is dependent on involving local health service groups, experts, and opinion leaders (both local and national). Patient-centered outcomes and cost-effectiveness of guideline implementation were considered important. It was acknowledged that there are many potentially effective ingredients for successful implementation, but a clear

  1. Patenting of university and non-university public research organisations in Germany: evidence from patent applications for medical research results.

    Directory of Open Access Journals (Sweden)

    Peter Tinnemann

    . Internationally mounting evidence questions the viability of policies to increase commercial exploitation of publicly funded research results. To evaluate the outcome of research policies a transparent evidence base for public debate is needed in Germany.

  2. A Research Agenda for Radiation Oncology: Results of the Radiation Oncology Institute's Comprehensive Research Needs Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Jagsi, Reshma, E-mail: rjagsi@med.umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Bekelman, Justin E. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Brawley, Otis W. [Department of Hematology and Oncology, Emory University, and American Cancer Society, Atlanta, Georgia (United States); Deasy, Joseph O. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Le, Quynh-Thu [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Michalski, Jeff M. [Department of Radiation Oncology, Washington University, St. Louis, MO (United States); Movsas, Benjamin [Department of Radiation Oncology, Henry Ford Health System, Detroit, MI (United States); Thomas, Charles R. [Department of Radiation Oncology, Oregon Health and Sciences University, Portland, OR (United States); Lawton, Colleen A. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, MI (United States); Hahn, Stephen M. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States)

    2012-10-01

    Purpose: To promote the rational use of scarce research funding, scholars have developed methods for the systematic identification and prioritization of health research needs. The Radiation Oncology Institute commissioned an independent, comprehensive assessment of research needs for the advancement of radiation oncology care. Methods and Materials: The research needs assessment used a mixed-method, qualitative and quantitative social scientific approach, including structured interviews with diverse stakeholders, focus groups, surveys of American Society for Radiation Oncology (ASTRO) members, and a prioritization exercise using a modified Delphi technique. Results: Six co-equal priorities were identified: (1) Identify and develop communication strategies to help patients and others better understand radiation therapy; (2) Establish a set of quality indicators for major radiation oncology procedures and evaluate their use in radiation oncology delivery; (3) Identify best practices for the management of radiation toxicity and issues in cancer survivorship; (4) Conduct comparative effectiveness studies related to radiation therapy that consider clinical benefit, toxicity (including quality of life), and other outcomes; (5) Assess the value of radiation therapy; and (6) Develop a radiation oncology registry. Conclusions: To our knowledge, this prioritization exercise is the only comprehensive and methodologically rigorous assessment of research needs in the field of radiation oncology. Broad dissemination of these findings is critical to maximally leverage the impact of this work, particularly because grant funding decisions are often made by committees on which highly specialized disciplines such as radiation oncology are not well represented.

  3. Dissemination of research results from Lund University to industry and society

    Science.gov (United States)

    Fahlander, Mirka

    2016-07-01

    Sweden is top ranked as the third most innovative nation in the world according to Global Innovation Index 2015. The academic staff at Swedish universities has the right to their inventions (research-ownership of patent rights) as opposed to far more diffuse university-ownership. Since 1977 the Swedish Higher Education Act imposes Swedish universities a so-called Third task. In addition to education and research they shall collaborate with the society and to inform the society about their activities. How does the largest university in Scandinavia deal with dissemination of research results to industry and society? The presentation will touch upon technology transfer, professional education and regional development as well as commercialization of research results.

  4. Population studies: return of research results and incidental findings Policy Statement.

    Science.gov (United States)

    Knoppers, Bartha Maria; Deschênes, Mylène; Zawati, Ma'n H; Tassé, Anne Marie

    2013-03-01

    The Public Population Project in Genomics and Society (P³G) is a not-for profit international consortium with members from more than 40 countries. Its objective is to lead, catalyze, and co-ordinate international efforts and expertise in order to optimize the use of population studies, biobanks, research databases, and other similar health and social science research infrastructures. The year 2011-2012 witnessed a plethora of special issues of journals on the return of results but few discussed the particular situation of population studies that serve as resources for future unspecified research. P³G considers it important to propose a policy that distinguishes between the contexts of population research and disease (clinical) research involving patients and then delineates actual and future obligations. The objectives of this Policy Statement are to: (1) delineate the particular characteristics of population studies, (2) distinguish the circumstances surrounding access by researchers to such studies, and (3) develop a framework for the return of research results and incidental findings.

  5. NASA Plan for Increasing Access to the Results of Scientific Research

    Science.gov (United States)

    2014-01-01

    This plan is issued in response to the Executive Office of the President's February 22, 2013, Office of Science and Technology Policy (OSTP) Memorandum for the Heads of Executive Departments and Agencies, "Increasing Access to the Results of Federally Funded Scientific Research." Through this memorandum, OSTP directed all agencies with more than $100 million in annual research and development expenditures to prepare a plan for improving the public's access to the results of federally funded research. The National Aeronautics and Space Administration (NASA) invests on the order of $3 billion annually in fundamental and applied research and technology development1 across a broad range of topics, including space and Earth sciences, life and physical sciences, human health, aeronautics, and technology. Promoting the full and open sharing of data with research communities, private industry, academia, and the general public is one of NASA's longstanding core values. For example, NASA's space and suborbital mission personnel routinely process, archive, and distribute their data to researchers around the globe. This plan expands the breadth of NASA's open-access culture to include data and publications for all of the scientific research that the Agency sponsors.

  6. Identifying Ethical Issues in Mental Health Research with Minors Adolescents: Results of a Delphi Study

    Directory of Open Access Journals (Sweden)

    Elisabeta Ioana Hiriscau

    2016-05-01

    Full Text Available Research with minors, especially for preventive purposes, e.g., suicide prevention, investigating risk or self-destructive behaviors such as deviance, drug abuse, or suicidal behavior, is ethically sensitive. We present a Delphi study exploring the ethical implications of the needs formulated by researchers in an international pre-conference who would benefit from ethics support and guidance in conducting Mental Health Research with minors. The resulting List of Ethical Issues (LEI was submitted to a 2-rounds Delphi process via the Internet, including 34 multidisciplinary experts. In the first round, the experts reviewed the LEI and completed a questionnaire. Results from this round were analyzed and grouped in nine categories comprising 40 items. In the second round, the experts had to agree/disagree with the needs expressed in the LEI leading to a final list of 25 ethical issues considered relevant for Mental Health Research with minors such as: confidentiality of the sensitive data, competence for consenting alone and risk of harm and stigma related to the methodology used in research. It was shown that studies like SEYLE (Saving and Empowering Young Lives in Europe trigger among researchers wishes to obtain specific recommendations helping to comply with standards for good practice in conducting research with minors.

  7. China's Exploration Research Resultful in the Eighth Five-Year Plan Period

    Institute of Scientific and Technical Information of China (English)

    Guan Defan; Yuan Lingling; Wang Keyu

    1997-01-01

    @@ The scientific research on oil and gas exploration, conducted by China National Petroleum Corporation (CNPC) during the Eighth Five-Year Plan Period (1991~1995),was carried out in the principle of "keeping the production stable in East China while accelerating exploration and development in West China." The research work is focused on the pattern of resources distribution and evaluation on selection of blocks for explorative targets. Meanwhile, the results of scientific research were applied to the exploration work, making greater achievements than in the previous five-yearplan period.

  8. Predicting Results of the Research Excellence Framework using Departmental h-Index -- Revisited

    CERN Document Server

    Mryglod, O; Holovatch, Yu; Berche, B

    2015-01-01

    We revisit our recent study [Predicting results of the Research Excellence Framework using departmental h-index, Scientometrics, 2014, 1-16; arXiv:1411.1996] in which we attempted to predict outcomes of the UK's Research Excellence Framework (REF~2014) using the so-called departmental $h$-index. Here we report that our predictions failed to anticipate with any accuracy either overall REF outcomes or movements of individual institutions in the rankings relative to their positions in the previous Research Assessment Exercise (RAE~2008).

  9. Summary results of an assessment of research projects in the superconductivity for electric power systems program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1992-10-01

    The Office of Program Analysis undertook an assessment of 37 research projects sponsored by the High Temperature Superconductivity Program. This report summarizes the results of the review. Rating factors included scientific and technical merit, mission relevance, appropriateness and level of innovation, quality of project team, productivity, and probable impact on the program`s mission. Some research needs and opportunities are described that were identified by the reviewers in the areas of wire development, deposited film technology, and systems development.

  10. Better Data Quality for Better Healthcare Research Results - A Case Study.

    Science.gov (United States)

    Hart, Robert; Kuo, Mu-Hsing

    2017-01-01

    Electronic Health Records (EHRs) have been identified as a key tool to collect data for healthcare research. However, EHR data must be of sufficient quality to support quality research results. Island Health, BC, Canada has invested and continues to invest in the development of solutions to address the quality of its EHR data and support high quality healthcare studies. This paper examines Island Health's data quality engine, its development and its successful implementation.

  11. A Hybrid Model Ranking Search Result for Research Paper Searching on Social Bookmarking

    Directory of Open Access Journals (Sweden)

    pijitra jomsri

    2015-11-01

    Full Text Available Social bookmarking and publication sharing systems are essential tools for web resource discovery. The performance and capabilities of search results from research paper bookmarking system are vital. Many researchers use social bookmarking for searching papers related to their topics of interest. This paper proposes a combination of similarity based indexing “tag title and abstract” and static ranking to improve search results. In this particular study, the year of the published paper and type of research paper publication are combined with similarity ranking called (HybridRank. Different weighting scores are employed. The retrieval performance of these weighted combination rankings are evaluated using mean values of NDCG. The results suggest that HybridRank and similarity rank with weight 75:25 has the highest NDCG scores. From the preliminary result of experiment, the combination ranking technique provide more relevant research paper search results. Furthermore the chosen heuristic ranking can improve the efficiency of research paper searching on social bookmarking websites.

  12. Relating cyclic voltammetry and impedance analysis in a viologen electrochromic device

    Energy Technology Data Exchange (ETDEWEB)

    Vergaz, Ricardo; Barrios, David; Sanchez-Pena, Jose-Manuel [Grupo de Displays y Aplicaciones Fotonicas, Department Tecnologia Electronica, Universidad Carlos III de Madrid, C/Butarque, 15, E28911 Leganes, Madrid (Spain); Pozo-Gonzalo, Cristina; Salsamendi, Maitane [Centre for Electrochemical Technologies (CIDETEC), Dept. Nuevos Materiales, Parque Tecnologico de San Sebastian - Paseo Miramon, 196, E-20009, San Sebastian (Spain)

    2009-12-15

    Viologens are electrochromic materials that have a wide range of coloration depending on the radical substituents. The results for a new blue viologen-based device, that has recently been patented, with an active area of 8.5 cm{sup 2} is presented in this paper. The characterization techniques used are based on optical measurements, chronoamperometry, cyclic voltammetry, and impedance spectroscopy analysis. A study of the results obtained from these measurements provides both an overview of the reactions taking place and has allowed an equivalent circuit to be developed which relates the different electrochemical parameters. The transmittance is observed to change from 80% to 15% in 600 nm for input voltages ranging from 0 to 2.5 V. However, increasing voltage beyond 1.8 V shows no optical change, thus, maintaining the voltage below this level optimizes the use of electrical current. Voltages and charges used for each redox reaction have been computed and are seen to be linearly related. The equivalent circuit generated to mimic the process has included parameters based on Warburg diffusion and double-layer capacitances. Results from this model are consistent with measurements for up to 1.8 V. Saturation of reduced species has been deduced for input voltages beyond this level. (author)

  13. Determination of Anionic Surfactants Using Atomic Absorption Spectrometry and Anodic Stripping Voltammetry

    Science.gov (United States)

    John, Richard; Lord, Daniel

    1999-09-01

    An experiment has been developed for our undergraduate analytical chemistry course that demonstrates the indirect analysis of anionic surfactants by techniques normally associated with metal ion determination; that is, atomic absorption spectroscopy (AAS) and anodic stripping voltammetry (ASV). The method involves the formation of an extractable complex between the synthetic surfactant anion and the bis(ethylenediamine)diaqua copper(II) cation. This complex is extracted into chloroform and then back-extracted into dilute acid. The resulting Cu(II) ions are determined by AAS and ASV. Students are required to determine the concentration of a pre-prepared "unknown" anionic surfactant solution and to collect and analyze a real sample of their choice. After the two extraction processes, students typically obtain close to 100% analytical recovery. Correlation between student AAS and ASV results is very good, indicating that any errors that occur probably result from their technique (dilutions, extractions, preparation of standards, etc.) rather than from the end analyses. The experiment is a valuable demonstration of the following analytical principles: indirect analysis; compleximetric analysis; liquid-liquid (solvent) extraction; back-extraction (into dilute acid); analytical recovery; and metal ion analysis using flame-AAS and ASV.

  14. CITIZENS INVOLVEMENT IN PUBLIC DECISIONS: BETWEEN NORMATIVE FRAMEWORK AND ACTUAL FINDINGS (II - RESEARCH RESULTS

    Directory of Open Access Journals (Sweden)

    Kolozsi Lucia

    2015-07-01

    Full Text Available Local communities’ needs must be addressed by an effective, loyal and transparent action of local institutions in the direction of ensuring participation of the citizens in undertaking decisions concerning that particular community. It is therefore necessary a good communication with the citizens of the local public institutions, and a proper and adequate information of citizens. After presenting in our previous research the main theoretical contributions in the theory of participatory democracy in local governance institutions, but also some practical considerations, including results and restrictions concerning how they are actually implemented in the Romanian public institutions, this paper focuses on presenting and analysing the results of our own researches. We present the results of the research carried out during 2014 on investigationg relevant concerning the public governance in local administration, and particularly in this paper how local administration facilitates the involvement of citizens in decision-making process and their participation in debating the main community issues.

  15. Innovation policies of SME's in the South Moravian and Moravian Silesian regions: results of the research

    Directory of Open Access Journals (Sweden)

    Tomáš Heralecký

    2009-01-01

    Full Text Available The aim of the paper was to identify the present situation in innovation policies of small and medium-sized enterprises in the South Moravian and Moravian Silesian regions. In order to achieve the specified objective, quantitative research was carried out in the small and medium-sized enterprises by way of questionnaires. The achieved results imply that the enterprises under investigation apply competitive strategy focusing on top quality of goods on offer. The research manifested that the companies focused markedly on innovations in supplying products on offer with additional functions or features. The research results show that the companies do not conduct changes in production organization frequently, not even following their earlier innovative activities. The results of the research into the innovative activity “change in product design” imply that this activity is not applied frequently in comparison with the above-mentioned activities. Based on the interviewed companies' weak points in human resources, the elementary drawbacks include lack of management's command of foreign languages as well as production staff's expert skills. The results of the research imply that the interviewed companies perceive the sphere of products (improved product quality, extension of a product range, the sphere of new technologies and the sphere of an increase in market potential as the most significant. The questionnaire inquiry shows that innovative and development activities are most frequently financed from companies' own funds, subsidies/grants, bank credits and leases. Mortgages and venture capital are only made used of occasionally.

  16. Determination of oleuropein using multiwalled carbon nanotube modified glassy carbon electrode by adsorptive stripping square wave voltammetry.

    Science.gov (United States)

    Cittan, Mustafa; Koçak, Süleyman; Çelik, Ali; Dost, Kenan

    2016-10-01

    A multi-walled carbon nanotube modified glassy carbon electrode was used to prepare an electrochemical sensing platform for the determination of oleuropein. Results showed that, the accumulation of oleuropein on the prepared electrode takes place with the adsorption process. Electrochemical behavior of oleuropein was studied by using cyclic voltammetry. Compared to the bare GCE, the oxidation peak current of oleuropein increased about 340 times at MWCNT/GCE. Voltammetric determination of oleuropein on the surface of prepared electrode was studied using square wave voltammetry where the oxidation peak current of oleuropein was measured as an analytical signal. A calibration curve of oleuropein was performed between 0.01 and 0.70µM and a good linearity was obtained with a correlation coefficient of 0.9984. Detection and quantification limits of the method were obtained as 2.73 and 9.09nM, respectively. In addition, intra-day and inter-day precision studies indicated that the voltammetric method was sufficiently repeatable. Finally, the proposed electrochemical sensor was successfully applied to the determination of oleuropein in an olive leaf extract. Microwave-assisted extraction of oleuropein had good recovery values between 92% and 98%. The results obtained with the proposed electrochemical sensor were compared with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis.

  17. Application of Pheno-Geographical Research Results in Forestry of Russia

    Directory of Open Access Journals (Sweden)

    A. I. Vidyakin

    2014-08-01

    Full Text Available The article shows the main results of pheno-geographical research of the Scots pine (Pinus sylvestris L. population-chorologic structure in the Russian plain, in the Southern Trans-Urals. It also suggests possible practical uses of these results in forestry of Russia. It is recommended to use the maps showing the spatial arrangement outline obtained during the research in developing seed zoning of the species. A system of silvicultural-economic measures aiming at restoring genetic variation and evolutionary-genetic processes in populations is discussed.

  18. The Neurolab Spacelab Mission: Neuroscience Research in Space: Results from the STS-90, Neurolab Spacelab Mission

    Science.gov (United States)

    Buckey, Jay C., Jr. (Editor); Homick, Jerry L. (Editor)

    2003-01-01

    Neurolab (STS-90) represents a major scientific achievement that built upon the knowledge and capabilities developed during the preceding 15 successful Spacelab module missions. NASA proposed a dedicated neuroscience research flight in response to a Presidential declaration that the 1990's be the Decade of the Brain. Criteria were established for selecting research proposals in partnership with the National Institutes of Health (NM), the National Science Foundation, the Department of Defense, and a number of the International Space Agencies. The resulting Announcement of Opportunity for Neurolab in 1993 resulted in 172 proposals from scientists worldwide. After an NIH-managed peer review, NASA ultimately selected 26 proposals for flight on the Neurolab mission.

  19. Instruments of the Marketing Mix in Non-Governmental Organizations – the Results of Empirical Research

    OpenAIRE

    Kwak, Wioletta

    2015-01-01

    The aim of the article is to present the instruments of the marketing mix of NGOs in light of empirical research. Marketing mix is the set of instruments for the implementation of marketing strategies of the organization. The paper presents selected results of research on the role of marketing strategies of non-profit organizations in creating value for stakeholders. In the literature one can find different concepts of “marketing mix”, for example, “4P”, “5P”, “7P”, “4C”. The survey results a...

  20. [From the production to the use of research results in care practice: a consolidating experience].

    Science.gov (United States)

    de Carvalho, Emília Campos; Laus, Ana Maria; Caliri, Maria Helena Larcher; Rossi, Luci Grupioni

    2010-01-01

    Although it is desirable that professionals use research results, often they are not prepared for that. This article aims to present the process of development and establishment of innovations, based on Rogers' model, through strategies to train nurses to use the best evidences for a quality clinical practice. It is a partnership between a educational institution and a hospital care institution. Following identification of problems from nurses' own practice in a health institution research proposals were developed to search for evidences and to test interventions. Results of this experience evidenced the viability of use of a model presented as a methodological framework what contributed to reach the institutions' goal.

  1. Summary results of an assessment of research projects in the National Photovoltaics Program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The Office of Energy Research (OER) undertook an assessment of 115 research projects (listed in Appendix A) sponsored by the National Photovoltaics Program. The Program is located within the Office of Energy Efficiency and Renewable Energy (EE). This report summarizes the results of that review. The Office of Solar Energy Conversion is responsible for the management of the National Photovoltaics Program. This program focuses on assisting US industry in development of fundamental technology to bring advanced photovoltaic energy systems to commercial use. The purpose of the assessment was to determine the following: (1) the quality of research of individual projects; (2) the impact of these individual projects on the mission of the program; and (3) the priority of future research opportunities.

  2. Evaluating the Potential of NASA's Earth Science Research Results for Improving Future Operational Systems

    Science.gov (United States)

    Frederick, M. E.; Cox, E. L.; Friedl, L. A.

    2006-12-01

    NASA's Earth Science Theme is charged with implementing NASA Strategic Goal 3A to "study Earth from space to advance scientific understanding and meet societal needs." In the course of meeting this objective, NASA produces research results, such as scientific observatories, research models, advanced sensor and space system technology, data active archives and interoperability technology, high performance computing systems, and knowledge products. These research results have the potential to serve society beyond their intended purpose of answering pressing Earth system science questions. NASA's Applied Sciences Program systematically evaluates the potential of the portfolio of research results to serve society by conducting projects in partnership with regional/national scale operational partners with the statutory responsibility to inform decision makers. These projects address NASA's National Applications and the societal benefit areas under the IEOS and GEOSS. Prototyping methods are used in two ways in NASA's Applied Sciences Program. The first is part of the National Applications program element, referred to as Integrated Systems Solutions (ISS) projects. The approach for these projects is to use high fidelity prototypes to benchmark the assimilation of NASA research results into our partners' decision support systems. The outcome from ISS projects is a prototype system that has been rigorously tested with the partner to understand the scientific uncertainty and improved value of their modified system. In many cases, these completed prototypes are adopted or adapted for use by the operational partners. The second falls under the Crosscutting Solutions program element, referred to as Rapid Prototyping (RP) experiments. The approach for RP experiments is to use low fidelity prototypes that are low cost and quickly produced to evaluate the potential of the breadth of NASA research results to serve society. The outcome from the set of RP experiments is an

  3. Return of individual research results and incidental findings in the clinical trials cooperative group setting.

    Science.gov (United States)

    Ferriere, Michael; Van Ness, Brian

    2012-04-01

    The National Cancer Institute (NCI)-funded cooperative group cancer clinical trial system develops experimental therapies and often collects samples from patients for correlative research. The cooperative group bank (CGB) system maintains biobanks with a current policy not to return research results to individuals. An online survey was created, and 10 directors of CGBs completed the surveys asking about understanding and attitudes in changing policies to consider return of incidental findings (IFs) and individual research results (IRRs) of health significance. The potential impact of the 10 consensus recommendations of Wolf et al. presented in this issue are examined. Reidentification of samples is often not problematic; however, changes to the current banking and clinical trial systems would require significant effort to fulfill an obligation of recontact of subjects. Additional resources, as well as a national advisory board would be required to standardize implementation.

  4. Diagnostic criteria for the characterization of quasireversible electron transfer reactions by cyclic square wave voltammetry.

    Science.gov (United States)

    Mann, Megan A; Helfrick, John C; Bottomley, Lawrence A

    2014-08-19

    Theory for cyclic square wave voltammetry of quasireversible electron transfer reactions is presented and experimentally verified. The impact of empirical parameters on the shape of the current-voltage curve is examined. From the trends, diagnostic criteria enabling the use of this waveform as a tool for mechanistic analysis of electrode reaction processes are presented. These criteria were experimentally confirmed using Eu(3+)/Eu(2+), a well-established quasireversible analyte. Using cyclic square wave voltammetry, both the electron transfer coefficient and rate were calculated for this analyte and found to be in excellent agreement with literature. When properly applied, these criteria will enable nonexperts in voltammetry to assign the electrode reaction mechanism and accurately measure electrode reaction kinetics.

  5. Fast voltammetry of metals at carbon-fiber microelectrodes: towards an online speciation sensor.

    Science.gov (United States)

    Pathirathna, Pavithra; Siriwardhane, Thushani; McElmurry, Shawn P; Morgan, Stephen L; Hashemi, Parastoo

    2016-11-14

    Speciation controls the chemical behavior of trace metals. Thus, there is great demand for rapid speciation analysis in a variety of fields. In this study, we describe the application of fast scan cyclic voltammetry (FSCV) and fast scan adsorption controlled voltammetry (FSCAV) to trace metal speciation analysis. We show that Cu(2+) can be detected using FSCAV in different matrices. We find that matrices with different Cu(2+) binding ability do not affect the equilibrium of Cu(2+) adsorption onto CFMs, and thus are an excellent predictor for free Cu(2+) ([Cu(2+)]free) in solution. We modelled a correlation between the FSCV response, [Cu(2+)]free and log Kf for 15 different Cu(2+) complexes. Using our model, we rapidly predicted, and verified [Cu(2+)]free and Kf of a real groundwater sample spiked with Cu(2+). We thus highlight the potential of fast voltammetry as a rapid trace metal speciation sensor.

  6. Application of power spectra patterns in Fourier transform square wave voltammetry to evaluate electrode kinetics of surface-confined proteins.

    Science.gov (United States)

    Fleming, Barry D; Barlow, Nicola L; Zhang, Jie; Bond, Alan M; Armstrong, Fraser A

    2006-05-01

    This paper describes an application of Fourier transform (FT) voltammetry that provides a quantitative evaluation of the electron-transfer kinetics of protein molecules attached to electrode surfaces. The potential waveform applied in these experiments consists of a large-amplitude square wave of frequency f superimposed onto the traditional triangular voltage used in dc cyclic voltammetry. The resultant current-time response, when Fourier transformed into the frequency domain, provides patterns of data at the even harmonic frequencies that arise from nonlinearity in the Faradaic response. These even harmonic contributions are ideally suited for kinetic evaluation of electron-transfer processes because they are highly selective to quasi-reversible behavior (insensitive to reversible or irreversible processes) and almost devoid of background charging current. Inverse FT methods can then be used to provide the wave shapes of the dc as well as the ac voltammetric components and other characteristics employed to detect the level of nonideality present relative to theoretical models based upon noninteracting surface-confined molecules. The new form of data evaluation has been applied to the electron-transfer properties of a typical biological electron carrier, the blue copper protein azurin, immobilized on polycrystalline gold electrodes modified with self-assembled monolayers of different length alkanethiols. Details of the electrode kinetics (rates of electron transfer, dispersion, and charge-transfer coefficients) as a function of alkanethiol, apparent surface coverage, and capacitance are all deduced from the square wave (FT-inverse FT) protocol, and the implications of these findings are considered.

  7. A kinetic study of ferrocenium cation decomposition utilizing an integrated electrochemical methodology composed of cyclic voltammetry and amperometry.

    Science.gov (United States)

    Singh, Archana; Chowdhury, Debarati Roy; Paul, Amit

    2014-11-21

    A novel, easy, quick, and inexpensive integrated electrochemical methodology composed of cyclic voltammetry and amperometry has been developed for the determination of the kinetic stability of higher oxidation states for inorganic complexes. In this study, ferrocene and its derivatives have been used as model systems and the corresponding ferrocenium cations were generated in situ during the electrochemical experiments to determine their kinetic stabilities. The study found that the ferrocenium cations decompose following the first-order kinetics at 27 ± 3 °C in the presence of ambient oxygen and water. The half-lives of the ferrocenium, carboxylate ferrocenium, and decamethyl ferrocenium cations were found to be 1.27 × 10(3), 1.52 × 10(3), and ≫11.0 × 10(3) s, respectively, in acetonitrile solvent having a 0.5 M tetrabutylammonium hexafluorophosphate electrolyte. These results are in agreement with the previous reports, i.e. the ferrocenium cation is unstable whereas the decamethyl ferrocenium cation has superior stability. The new methodology has been established by performing various experiments using different concentrations of ferrocene, variable scan rates in cyclic voltammetry, different time periods for amperometry, and in situ spectroelectrochemical experiments.

  8. Lead detection using micro/nanocrystalline boron-doped diamond by square-wave anodic stripping voltammetry.

    Science.gov (United States)

    Arantes, Tatiane M; Sardinha, André; Baldan, Mauricio R; Cristovan, Fernando H; Ferreira, Neidenei G

    2014-10-01

    Monitoring heavy metal ion levels in water is essential for human health and safety. Electroanalytical techniques have presented important features to detect toxic trace heavy metals in the environment due to their high sensitivity associated with their easy operational procedures. Square-wave voltammetry is a powerful electrochemical technique that may be applied to both electrokinetic and analytical measurements, and the analysis of the characteristic parameters of this technique also enables the mechanism and kinetic evaluation of the electrochemical process under study. In this work, we present a complete optimized study on the heavy metal detection using diamond electrodes. It was analyzed the influence of the morphology characteristics as well as the doping level on micro/nanocrystalline boron-doped diamond films by means of square-wave anodic stripping voltammetry (SWASV) technique. The SWASV parameters were optimized for all films, considering that their kinetic response is dependent on the morphology and/or doping level. The films presented reversible results for the Lead [Pb (II)] system studied. The Pb (II) analysis was performed in ammonium acetate buffer at pH 4.5, varying the lead concentration in the range from 1 to 10 μg L(-1). The analytical responses were obtained for the four electrodes. However, the best low limit detection and reproducibility was found for boron doped nanocrystalline diamond electrodes (BDND) doped with 2000 mg L(-1) in B/C ratio.

  9. Determination of buprenorphine by differential pulse voltammetry on carbon paste electrode using SDS as an enhancement factor.

    Science.gov (United States)

    Behpour, Mohsen; Valipour, Akram; Keshavarz, Mahin

    2014-09-01

    In the present study, a facile electrochemical approach is proposed for the determination of buprenorphine (BPR) in the presence of sodium dodecyl sulfate (SDS). SDS was applied for amplification of oxidation signal. Carbon paste electrode (CPE) used as working electrode and cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were carried out in phosphate buffer solution (pH3.0). Under optimal experimental conditions, the oxidation current increased with the addition of BPR in the sample and two dynamic ranges obtained from 4.00 nM to 0.126 μM and from 0.126 to 0.317 μM by DPV and exhibited a low detection limit (LOD) of 1.33 nM (S/N=3). This offered method has been used for the determination of BPR in the real samples and has validated with the recovery test for BPR spiked urine samples. The result demonstrated that this method is a simple, sensitive, rapid, low-cost, and stable method for BPR detection.

  10. Determination of propylthiouracil in pharmaceuticals by differential pulse voltammetry using a cathodically pretreated boron-doped diamond electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, Elen Romao [Universidade Estadual de Londrina, PR (Brazil). Dept. de Quimica; Trench, Aline Barrios; Rocha-Filho, Romeu C.; Fatibello-Filho, Orlando, E-mail: bello@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2013-09-15

    A simple procedure is described for the determination of propylthiouracil (PTU) by differential pulse voltammetry (DPV) using a cathodically pretreated boron-doped diamond (BDD) electrode. Cyclic voltammetry studies indicate that the oxidation of PTU is irreversible at a peak potential of 1.42 V (vs. Ag/AgCl (3.0 mol L{sup -1} KCl)) in a Britton-Robinson (BR) buffer solution (pH 2.0). Under optimized conditions, the obtained analytical curve was linear (r = 0.9985) for the PTU concentration range of 1.0 to 29.1 {mu}mol L{sup -1} in a BR buffer solution (pH 2.0), with a detection limit of 0.90 {mu}mol L{sup -1}. The proposed method was successfully applied in the determination of PTU in pharmaceutical samples, with results in agreement at a 95% confidence level with those obtained using an official titration method. (author)

  11. Affecting of aquatic vascular plant Lemna minor by cisplatin revealed by voltammetry.

    Science.gov (United States)

    Supalkova, Veronika; Beklova, Miroslava; Baloun, Jiri; Singer, Christoph; Sures, Bernd; Adam, Vojtech; Huska, Dalibor; Pikula, Jiri; Rauscherova, Libuse; Havel, Ladislav; Zehnalek, Josef; Kizek, Rene

    2008-02-01

    Within the context of application of platinum derivates based effective cytostatics, we can suppose that these risk metals can get into aquatic ecosystems where they can show biologic availability for food chain. In the present work we report on investigation of affecting of duckweed (Lemna minor) by various doses of cisplatin (0, 5, 10, 20, 40, 80 and 160 microM) for 4 days. The toxic influence of cisplatin was evaluated on the basis of growth inhibition expressed as number of leaves, growth rate, and total amount of biomass. The result value of 96hEC50, calculated from growth inhibition with comparison of growth rates, was 6.93 microM. Moreover we aimed on determination of cisplatin content using differential pulse voltammetry. The highest content of cisplatin (320 ng g(-1) of fresh weight) was determined in plants treated by 80 microM at the second day of treatment. Plants protect themselves against heavy metals by means of synthesis of cysteine-rich peptides such as glutathione and phytochelatins. Thus thiol determination in the treated plants by means of Brdicka reaction followed. The marked increase in thiol concentration detected is associated with defence reaction of the plant against stress caused by cisplatin.

  12. Characterization and DNA binding studies of unexplored imidazolidines by electronic absorption spectroscopy and cyclic voltammetry.

    Science.gov (United States)

    Shah, Afzal; Nosheen, Erum; Munir, Shamsa; Badshah, Amin; Qureshi, Rumana; Rehman, Zia-Ur-; Muhammad, Niaz; Hussain, Hidayat

    2013-03-05

    UV-Vis spectroscopic behavior of four imidazolidine derivatives i.e., [5-benzylideneimidazolidine-2,4-dione (NBI), 5-(2-hydroxybenzylidene)imidazolidine-2,4-dione (HBI), 5-(4-methoxybenzylidene)imidazolidine-2,4-dione (MBI) and 5-(3,4-di-methoxybenzylidene)imidazolidine-2,4-dione (DBI)] was studied in a wide pH range. Spectroscopic response of the studied compounds was found sensitive to pH and the attached substituents. Incited by anti-tumor activity, structural miscellany and biological applications of imidazolidines, the DNA binding affinity of some novel derivatives of this class of compounds was examined by cyclic voltammetry (CV) and UV-Vis spectroscopy at pH values of blood (7.4) and lysosomes (4.5). The CV results showed the following order of binding strength: KNBI (6.40×10(6)M(-1))>KHBI (1.77×10(5)M(-1))>KMBI (2.06×10(4)M(-1))>KDBI (1.01×10(4)M(-1)) at pH 7.4. The same order was also obtained from UV-Vis spectroscopy. The greater affinity of NBI justified its preferred candidature as an effective anti-cancer drug. The DNA binding propensity of these compounds was found comparable or greater than most of the clinically used anticancer drugs. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Detecting Naturally-Produced Sulfide Nanoparticles by Adsorptive, Cathodic Stripping Voltammetry.

    Science.gov (United States)

    Helz, G. R.; Krznaric, D.; Bura-Nakic, E.; Ciglenecki, I.

    2007-12-01

    Growing evidence implies that metal sulfide nanoparticles of natural origin exist in some aquatic environments. These nanoparticles could play important roles as mediators of trace metal nutrition and toxicity. Thermodynamics suggests that in sulfidic environments (total transition metaltotal sulfide) the most insoluble metal sulfide (usually Hg or Cu) will form the predominant sulfide nanoparticle. New experimental methods for detecting and distinguishing between such nanoparticles are needed. We report that mercury electrodes effectively preconcentrate a number of different metal sulfide nanoparticles, enabling their detection by adsorptive cathodic stripping voltammetry. Voltammetrically, nanoparticulate analytes differ fundamentally from dissolved analytes; e.g. analyte accumulation is very sensitive to electrolyte composition and concentration in accord with the Schulze-Hardy Rule. EDTA or acid treatment of samples is useful for distinguishing highly insoluble nanoparticles (HgS, CuS) from FeS. Nanoparticulate sulfur potentially interferes. Supersaturated solutions can generate artifactual analyte on Hg electrode surfaces. Despite such potential pitfalls, progress is encouraging. Preliminary, qualitative results from natural waters will be reported.

  14. Simultaneous measurement and quantitation of 4-hydroxyphenylacetic acid and dopamine with fast-scan cyclic voltammetry.

    Science.gov (United States)

    Shin, Mimi; Kaplan, Sam V; Raider, Kayla D; Johnson, Michael A

    2015-05-07

    Caged compounds have been used extensively to investigate neuronal function in a variety of preparations, including cell culture, ex vivo tissue samples, and in vivo. As a first step toward electrochemically measuring the extent of caged compound photoactivation while also measuring the release of the catecholamine neurotransmitter, dopamine, fast-scan cyclic voltammetry at carbon-fiber microelectrodes (FSCV) was used to electrochemically characterize 4-hydroxyphenylacetic acid (4HPAA) in the absence and presence of dopamine. 4HPAA is a by-product formed during the process of photoactivation of p-hydroxyphenacyl-based caged compounds, such as p-hydroxyphenylglutamate (pHP-Glu). Our data suggest that the oxidation of 4HPAA occurs through the formation of a conjugated species. Moreover, we found that a triangular waveform of -0.4 V to +1.3 V to -0.4 V at 600 V s(-1), repeated every 100 ms, provided an oxidation current of 4HPAA that was enhanced with a limit of detection of 100 nM, while also allowing the detection and quantitation of dopamine within the same scan. Along with quantifying 4HPAA in biological preparations, the results from this work will allow the electrochemical measurement of photoactivation reactions that generate 4HPAA as a by-product as well as provide a framework for measuring the photorelease of electroactive by-products from caged compounds that incorporate other chromophores.

  15. Cyclic voltammetry investigation of diffusion of ferrocene within propylene carbonate organogel formed by gelator

    Energy Technology Data Exchange (ETDEWEB)

    Feng Guilong; Xiong Yun; Wang Hong [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430074 (China); Yang Yajiang [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan 430074 (China)], E-mail: yjyang@mail.hust.edu.cn

    2008-11-30

    Propylene carbonate organogel containing LiClO{sub 4} was formed in the presence of gelator bis-(4-stearoylaminophenyl) methane (BSAPM). The electrochemical behavior and diffusion of ferrocene (Fc) and ferricenium (Fc{sup +}) entrapped within the organogel was investigated by cyclic voltammetry. The Fc molecules still show redox activity within the organogels in comparison with corresponding solutions of propylene carbonate containing LiClO{sub 4}. The shape of the cyclic voltammograms of the Fc electrooxidation in organogel was similar to that in corresponding solutions. The results indicated that redox reactions of Fc/Fc{sup +} were a quasi-reversible process of diffusion-controlled single electron transfer in organogels. The diffusion coefficients of Fc and Fc{sup +} in organogels decreased with an increase of the concentration of gelator BSAPM, but increased with an increase of temperature. The temperature dependence of the diffusion coefficient in organogels followed classical Arrhenius equation. The activation energy in organogels was found of no difference from that in corresponding solutions.

  16. Solid electrolyte gas sensors based on cyclic voltammetry with one active electrode

    Energy Technology Data Exchange (ETDEWEB)

    Jasinski, G; Jasinski, P, E-mail: gregor@biomed.eti.pg.gda.pl [Gdansk University of Technology, Faculty of Electronics, Telecommunication and Informatics, Narutowicza 11/12, 80-233 Gdansk (Poland)

    2011-10-29

    Solid state gas sensors are cost effective, small, rugged and reliable. Typically electrochemical solid state sensors operate in either potentiometric or amperometric mode. However, a lack of selectivity is sometimes a shortcoming of such sensors. It seems that improvements of selectivity can be obtained in case of the electrocatalytic sensors, which operate in cyclic voltammetry mode. Their working principle is based on acquisition of an electric current, while voltage ramp is applied to the sensor. The current-voltage response depends in a unique way on the type and concentration of ambient gas. Most electrocatalytic sensors have symmetrical structure. They are in a form of pellets with two electrodes placed on their opposite sides. Electrochemical reactions occur simultaneously on both electrodes. In this paper results for sensors with only one active electrode exposed to ambient gas are presented. The other electrode was isolated from ambient gas with dielectric sealing. This sensor construction allows application of advanced measuring procedures, which permit sensor regeneration acceleration. Experiments were conducted on Nasicon sensors. Properties of two sensors, one with one active electrode and second with symmetrical structure, used for the detection of mixtures of NO{sub 2} and synthetic air are compared.

  17. Failure of Standard Training Sets in the Analysis of Fast-Scan Cyclic Voltammetry Data.

    Science.gov (United States)

    Johnson, Justin A; Rodeberg, Nathan T; Wightman, R Mark

    2016-03-16

    The use of principal component regression, a multivariate calibration method, in the analysis of in vivo fast-scan cyclic voltammetry data allows for separation of overlapping signal contributions, permitting evaluation of the temporal dynamics of multiple neurotransmitters simultaneously. To accomplish this, the technique relies on information about current-concentration relationships across the scan-potential window gained from analysis of training sets. The ability of the constructed models to resolve analytes depends critically on the quality of these data. Recently, the use of standard training sets obtained under conditions other than those of the experimental data collection (e.g., with different electrodes, animals, or equipment) has been reported. This study evaluates the analyte resolution capabilities of models constructed using this approach from both a theoretical and experimental viewpoint. A detailed discussion of the theory of principal component regression is provided to inform this discussion. The findings demonstrate that the use of standard training sets leads to misassignment of the current-concentration relationships across the scan-potential window. This directly results in poor analyte resolution and, consequently, inaccurate quantitation, which may lead to erroneous conclusions being drawn from experimental data. Thus, it is strongly advocated that training sets be obtained under the experimental conditions to allow for accurate data analysis.

  18. Determination of water in room temperature ionic liquids by cathodic stripping voltammetry at a gold electrode.

    Science.gov (United States)

    Zhao, Chuan; Bond, Alan M; Lu, Xunyu

    2012-03-20

    An electrochemical method based on cathodic stripping voltammetry at a gold electrode has been developed for the determination of water in ionic liquids. The technique has been applied to two aprotic ionic liquids, (1-butyl-3-ethylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate), and two protic ionic liquids, (bis(2-hydroxyethyl)ammonium acetate and triethylammonium acetate). When water is present in an ionic liquid, electrooxidation of a gold electrode forms gold oxides. Thus, application of an anodic potential scan or holding the potential of the electrode at a very positive value leads to accumulation of an oxide film. On applying a cathodic potential scan, a sensitive stripping peak is produced as a result of the reduction of gold oxide back to gold. The magnitude of the peak current generated from the stripping process is a function of the water concentration in an ionic liquid. The method requires no addition of reagents and can be used for the sensitive and in situ determination of water present in small volumes of ionic liquids. Importantly, the method allows the determination of water in the carboxylic acid-based ionic liquids, such as acetate-based protic ionic liquids, where the widely used Karl Fischer titration method suffering from an esterification side reaction which generates water as a side product.

  19. Underpotential Deposition Study and Determination of Bismuth on Gold Electrode by Using Voltammetry

    Institute of Scientific and Technical Information of China (English)

    DU,Yong-Ling(杜永令); WANG,Chun-Ming(王春明)

    2002-01-01

    The cyclic voltammetry (CV) and the semidifferential anodic stripping voltanmetry (SdASV) were used for investigation of bismuth(Ⅲ) underpotential deposition (UPD) on gold electrode. Based on the excellent electrochemical properties of Au/Bi UPD system, a new method for determining bismuth (Ⅲ)was established. A solution of 0.1 mol/L HNO3 was selected as the supporting electrolyte. Factors affecting the Bi(Ⅲ) UPD and stripping steps were investigated and an opthmized analytical procedure was developed. The calibration plots for Bi(Ⅲ) concentration in the range 1.25 × 10-8-1.0 × 10-7 mol/L were obtained. The detection limit, calculated as three times the standard deviation of the analytical signal of 8.3×10-8 mol/L for a 90 s electrodeposition at 0.00 V (while the solution magnetically stirred at a speed of 300 rpm), was 7.5× 10-9 mol/ L. For8 successive determinations of 1.25 × 10-7 mol/L Bi(Ⅲ), the obtained RSD (relative standard deviation) was 0.4%. The developed method was applied to bismuth determining in medicine and urine samples. The analytical results were compared with that of atomic emission spectrometry (AES) method.

  20. Coulometric differential FFT admittance voltammetry determination of Amlodipine in pharmaceutical formulation by nano-composite electrode.

    Science.gov (United States)

    Norouzi, Parviz; Gupta, Vinod Kumar; Larijani, Bagher; Rasoolipour, Solmaz; Faridbod, Farnoush; Ganjali, Mohammad R

    2015-01-01

    An electrochemical detection technique based on combination of was coulometric differential fast Fourier transformation admittance voltammetry (CDFFTAV) and nano-composite film modified glassy carbon electrode was successfully applied for sensitive determination of Amlodipine. The nano-composite film was made by a mixture of ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), multiwall carbon nanotube and Au nanoparticles as electrochemical mediators. Studies reveal that the irreversible oxidation of Amlodipine was highly facile on the electrode surface. The electrochemical response was established on calculation of the charge under the admittance peak, which was obtained by discrete integration of the admittance response in a selected potential range, obtained in a flow injection analysis. Once established the best operative optimum conditions, the resulting nano-composite film electrode showed a catalytic effect on the oxidation of the analyte. The response is linear in the Amlodipine concentration range of 1.0 × 10(-9) to 2.0 × 10(-7)M with a detection limit of 1.25 × 10(-10)M. Moreover, the proposed technique exhibited high sensitivity, fast response time (less than 6s) and long-term stability and reproducibility around 96%, and it was successfully used to the determination of Amlodipine content in the pharmaceutical formulation.

  1. Determination of Sulpiride by Linear Sweep Stripping Voltammetry at a Mercury Electrode

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper reports the electrochemical properties of sulpiride at a mercury electrode, especially its adsorptive characteristic. Sulpiride dissolved in a supporting electrolyte of a McIlvaine buffer at pH 6.8 represents a sensitive and well defined reduction wave by linear sweep stripping voltammetry. This method is based on the pre-concentration and the reduction of sulpiride at a hung mercury drop electrode. The reduction peak potential is -1.72 V(vs. Ag-AgCl) and the peak current is proportional to the concentration of sulpiride in the range of 0.1-0.6 μg/mL. The detection limit is 0.025 μg/mL obtained under the experimental conditions selected in this work. The electrochemical properties of this system were investigated, and the proposed method was applied to the determination of sulpiride in pharmaceutical tablets with satisfactory results. It was compared well with the UV spectrophotometric method, showing a superior sensitivity.

  2. Determination of copper speciation in highway stormwater runoff using competitive ligand exchange - Adsorptive cathodic stripping voltammetry.

    Science.gov (United States)

    Nason, Jeffrey A; Sprick, Matthew S; Bloomquist, Don J

    2012-11-01

    Low concentrations of dissolved copper have been shown to adversely affect the olfactory system of salmonid species, impairing their ability to avoid predators and likely increasing mortality. These studies have resulted in increased regulatory scrutiny of stormwater discharges to surface waters inhabited by threatened and endangered salmonid species. Because it is primarily the free ionic (Cu(2+)) and weakly complexed forms of copper that are bioavailable, it is critical to understand the speciation of copper in stormwater. This paper reports on the characterization of copper binding ligands and copper speciation in composite samples of highway stormwater runoff collected at four sites in Oregon, USA using competitive ligand exchange - adsorptive cathodic stripping voltammetry (CLE-ACSV). Although the concentration and strength of copper binding ligands in stormwater varied considerable between sites and storms, the vast majority (>99.9%) of the total dissolved copper in composite samples was complexed by organic ligands in stormwater. Although total dissolved copper concentrations range from 2 to 20 μg/L, the analytically determined free ionic copper concentrations did not exceed 10(-10) M (6.3 ng/L) in any of the fully characterized samples, suggesting that much of the copper in highway stormwater is not bioavailable. Analytically determined free ionic copper concentrations were compared with those predicted by a readily available chemical equilibrium models and found to be in reasonable agreement. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Chemical speciation of iron in seawater by cathodic stripping voltammetry with dihydroxynaphthalene.

    Science.gov (United States)

    van den Berg, Constant M G

    2006-01-01

    The chemical speciation of iron in seawater is determined by cathodic stripping voltammetry using 2,3-dihydroxynaphthalene (DHN) as adsorptive and competing ligand. The optimized conditions include a DHN concentration of 0.5-1 microM, seawater at its original pH of 8, and equilibration overnight. The alpha-coefficient for DHN (=[FeDHN]/[Fe']) was calibrated against EDTA giving values of 166 for 0.5 microM DHN and 366 at 1 microM DHN and a value of 8.51 +/- 0.07 for log K'(Fe'DHN). The dissociation of the natural iron species FeL was found to have a characteristic reaction time of 50 min, indicating that titrations should be equilibrated overnight rather than the shorter periods sometimes used onboard ship. The method was applied to samples from the Pacific giving ligand concentrations of 1.1 and 1.6 nM for deep and surface waters, respectively, with an average value for log K'(FeL) of 11.9 +/- 0.3 compared to a value of 11.5 for the siderophore deferoxamine. The results are similar to those obtained previously for similar samples, but the new method has much greater sensitivity for iron than previous methods, leading to lower limits of detection and shorter analysis time.

  4. Electrochemical analysis of the alanine phenylthiohydantoin derivative by cathodic stripping voltammetry.

    Science.gov (United States)

    Vilaseca, C; Quintana, M C; Vicente, J; Hernández, P; Hernández, L

    2008-08-01

    A square-wave cathodic stripping voltammetry method for alanine determination as its phenylthiohydantoin (PTH-alanine) derivative is developed. To this end, all the chemical and instrumental variables affecting the determination of PTH-alanine are optimized. From studies of the mechanisms governing the electrochemical response of PTH-alanine, it was concluded that it is an electrochemically irreversible system with a diffusive-adsorptive reduction phenomenon. Under optimal conditions, the variation of analytical signal (I(p)) with PTH-alanine concentration is linear in the 2.4x10(-8)-4.8x10(-7) M range, with a LOD of 1.2x10(-8) M and a LOQ of 4.2x10(-8) M, a RSD (%) less than 11%, and a E(r) (%) less than 10%. The optimized method was applied to the determination of PTH-alanine obtained from a synthetic protein after Edman reaction and the results were corroborated by high-performance liquid chromatography with UV detection.

  5. SQUARE WAVE CATHODIC STRIPPING VOLTAMMETRY ADSORPTIVE FOR NICKEL AND COBALT ANALYSIS

    Directory of Open Access Journals (Sweden)

    Saryati Saryati

    2010-06-01

    Full Text Available The adsorptive stripping voltammetric determination of Ni and Co based on adsorption of the Ni/Co and dimethylglioxime (DMG complex on a hanging mercury drop electrode is studied. The reduction current of the adsorbed DMG complex is measured by square wave cathodic stripping voltammetry method. The effect of various parameters such as ligand concentration, pH of supporting electrolytic, adsorption potential and adsorption time on the current peak of Ni and Co voltammogram were studied. Optimum condition of this method are supporting electrolyte pH 9, DMG concentration 5×10 -4 M, adsorption potential -0.7 V vs Ag/AgCl and adsorption time 180 second. A linier relationship between the current peak and Ni or Co concentration was obtained in the range 5 - 30 ng/mL and the detection limit 0.6 ng/ml for both Ni and Co. The recovery of Ni and Co were 98.11-104.17% using standard biological materials with RSD 2.59 - 10.37%. Based on ";t"; test can be conclude that the result are nearly equal to the standard reference material.   Keywords: adsorptive stripping voltammetric, dimethylglioxime complex, nickel, cobalt

  6. Cathodic stripping voltammetry of nickel: sonoelectrochemical exploitation of the Ni(III)/Ni(II) couple.

    Science.gov (United States)

    Davis, James; Vaughan, D Huw; Stirling, David; Nei, Lembit; Compton, Richard G

    2002-07-19

    The exploitation of the Ni(III)/Ni(II) transition as a means of quantifying the concentration of nickel within industrial samples was assessed. The methodology relies upon the reagentless electrodeposition of Ni onto a glassy carbon electrode and the subsequent oxidative conversion of the metallic layer to Ni(III). The analytical signal is derived from a cathodic stripping protocol in which the reduction of the Ni(III) layer to Ni(II) is monitored through the use of square wave voltammetry. The procedure was refined through the introduction of an ultrasonic source which served to both enhance the deposition of nickel and to remove the nickel hydroxide layer that results from the measurement process. A well-defined stripping peak was observed at +0.7 V (vs. Agmid R:AgCl) with the response found to be linear over the range 50 nM to 1 muM (based on a 30 s deposition time). Other metal ions such as Cu(II), Mn(II), Cr(III), Pb(II), Cd(II), Zn(II), Fe(III) and Co(II) did not interfere with the response when present in hundred fold excess. The viability of the technique was evaluated through the determination of nickel within a commercial copper nickel alloy and validated through an independent comparison with a standard ICP-AES protocol.

  7. Single-photon sources for quantum technologies - Results of the joint research project SIQUTE

    DEFF Research Database (Denmark)

    Kück, S.; López, M.; Rodiek, B.

    2017-01-01

    In this presentation, the results of the joint research project “Single-Photon Sources for Quantum Technologies” (SIQUTE) [1] will be presented. The focus will be on the development of absolutely characterized single-photon sources, on the realization of an efficient waveguide-based single-photon...

  8. Compendium of Read 180 Research: 16 Years of Evidence-Based Results for America's Struggling Readers

    Science.gov (United States)

    Online Submission, 2015

    2015-01-01

    In school districts across the nation, diverse student groups, including English Learners and students with disabilities, have been experiencing significant gains in reading performance after using READ 180. This compendium of READ 180 research contains results of 40 studies conducted in a variety of settings, in school districts across the…

  9. Reporting genetic results in research studies: summary and recommendations of an NHLBI working group.

    Science.gov (United States)

    Bookman, Ebony B; Langehorne, Aleisha A; Eckfeldt, John H; Glass, Kathleen C; Jarvik, Gail P; Klag, Michael; Koski, Greg; Motulsky, Arno; Wilfond, Benjamin; Manolio, Teri A; Fabsitz, Richard R; Luepker, Russell V

    2006-05-15

    Prospective epidemiologic studies aid in identifying genetic variants associated with diseases, health risks, and physiologic traits. These genetic variants may eventually be measured clinically for purposes of diagnosis, prognosis, and treatment. As evidence of the potential clinical value of such information accrues, research studies face growing pressure to report these results to study participants or their physicians, even before sufficient evidence is available to support widespread screening of asymptomatic persons. There is thus a need to begin to develop consensus on whether and when genetic findings should be reported to participants in research studies. The National Heart, Lung, and Blood Institute (NHLBI) convened a Working Group on Reporting Genetic Results in Research Studies to discuss if, when, and how genetic information should be reported to study participants. The Working Group concluded that genetic test results should be reported to study participants when the associated risk for the disease is significant; the disease has important health implications such as premature death or substantial morbidity or has significant reproductive implications; and proven therapeutic or preventive interventions are available. Finally, the Working Group recommended procedures for reporting genetic research results and encouraged increased efforts to create uniform guidelines for this activity.

  10. Proactive Encouragement of Interdisciplinary Research Teams in a Business School Environment: Strategy and Results

    Science.gov (United States)

    Adams, Susan M.; Carter, Nathan C.; Hadlock, Charles R.; Haughton, Dominique M.; Sirbu, George

    2008-01-01

    This case study describes efforts to promote collaborative research across traditional boundaries in a business-oriented university as part of an institutional transformation. We model this activity within the framework of social network analysis and use quantitative tools from that field to characterize resulting impacts. (Contains 4 tables and 2…

  11. Changing requirements and resulting needs for IT-infrastructure for longitudinal research in the neurosciences.

    Science.gov (United States)

    Buckow, Karoline; Quade, Matthias; Rienhoff, Otto; Nussbeck, Sara Y

    2016-01-01

    The observation of growing "difficulties" in IT-infrastructures in neuroscience research during the last years led to a search for reasons and an analysis on how this phenomenon is reflected in the scientific literature. With a retrospective analysis of nine examples of multicenter research projects in the neurosciences and a literature review the observation was systematically analyzed. Results show that the rise in complexity mainly stems from two reasons: (1) more and more need for information on quality and context of research data (metadata) and (2) long-term requirements to handle the consent and identity/pseudonyms of study participants and biomaterials in relation to legal requirements. The combination of these two aspects together with very long study times and data evaluation periods are components of the subjectively perceived "difficulties". A direct consequence of this result is that big multicenter trials are becoming part of integrated research data environments and are not standing alone for themselves anymore. This drives up the resource needs regarding the IT-infrastructure in neuroscience research. In contrast to these findings, literature on this development is scarce and the problem probably underestimated.

  12. Initial experience with a group presentation of study results to research participants

    Directory of Open Access Journals (Sweden)

    Bent Stephen

    2008-03-01

    Full Text Available Abstract Background Despite ethical imperatives, informing research participants about the results of the studies in which they take part is not often performed. This is due, in part, to the costs and burdens of communicating with each participant after publication of the results. Methods Following the closeout and publication of a randomized clinical trial of saw palmetto for treatment of symptoms of benign prostatic hyperplasia, patients were invited back to the research center to participate in a group presentation of the study results. Results Approximately 10% of participants attended one of two presentation sessions. Reaction to the experience of the group presentation was very positive among the attendees. Conclusion A group presentation to research participants is an efficient method of communicating study results to those who desire to be informed and was highly valued by those who attended. Prospectively planning for such presentations and greater scheduling flexibility may result in higher attendance rates. Trial Registration Number Clinicaltrials.gov #NCT00037154

  13. Integrating the results of user research into medical device development: insights from a case study

    Directory of Open Access Journals (Sweden)

    Martin Jennifer L

    2012-07-01

    Full Text Available Abstract Background It is well established that considering users is an important aspect of medical device development. However it is also well established that there are numerous barriers to successfully conducting user research and integrating the results into product development. It is not sufficient to simply conduct user research, it must also be effectively integrated into product development. Methods A case study of the development of a new medical imaging device was conducted to examine in detail how users were involved in a medical device development project. Two user research studies were conducted: a requirements elicitation interview study and an early prototype evaluation using contextual inquiry. A descriptive in situ approach was taken to investigate how these studies contributed to the product development process and how the results of this work influenced the development of the technology. Data was collected qualitatively through interviews with the development team, participant observation at development meetings and document analysis. The focus was on investigating the barriers that exist to prevent user data from being integrated into product development. Results A number of individual, organisational and system barriers were identified that functioned to prevent the results of the user research being fully integrated into development. The user and technological aspects of development were seen as separate work streams during development. The expectations of the developers were that user research would collect requirements for the appearance of the device, rather than challenge its fundamental concept. The manner that the user data was communicated to the development team was not effective in conveying the significance or breadth of the findings. Conclusion There are a range of informal and formal organisational processes that can affect the uptake of user data during medical device development. Adopting formal decision

  14. Analysis of earth pigments in Palomino's frescoes in the Santos Juanes Church in Valencia (Spain) by solid state voltammetry and FTIR spectroscopy

    OpenAIRE

    DOMENECH CARBO, ANTONIO; Domenech Carbo, Mª Teresa; Ciarrocchi, Julia; Cialei, Vania; Monteagudo, Antonio

    2006-01-01

    A combination of solid-state voltammetry and Fourier transform infrared spectroscopy in the attenuated total reflectance mode was applied to identify earth pigments in samples from the frescoes of Antonio Palomino (dated 1707) taken from the vault of the Santos Juanes church in Valencia (Spain). Such frescoes suffered considerable damage by fire during the Spanish Civil War in 1936, resulting in severe chemical and chromatic alterations. Se ha utilizado una combinación de voltamperometría ...

  15. Detection of gamma-irradiation effect on DNA and protein using magnetic sensor and cyclic voltammetry.

    Science.gov (United States)

    Park, Duck-Gun; Song, Hoon; Kishore, M B; Vértesy, G; Lee, Duk-Hyun

    2013-11-01

    In this study, a magnetic sensor utilizing Planar Hall Resistance (PHR) and cyclic Voltammetry (CV) for detecting the radiation effect was fabricated. Specifically, we applied in parallel a PHR sensor and CV device to monitor the irradiation effect on DNA and protein respectively. Through parallel measurements, we demonstrated that the PHR sensor and CV are sensitive enough to measure irradiation effect. The PHR voltage decreased by magnetic nanobead labeled DNA was slightly recovered after gamma ray irradiation. The behavior of cdk inhibitor protein p21 having a sandwich structure of Au/protein G/Ab/Ag/Ab was checked by monitoring the cyclic Voltammetry signal in analyzing the gamma ray irradiation effect.

  16. Cyclic Square Wave Voltammetry of Surface-Confined Quasireversible Electron Transfer Reactions.

    Science.gov (United States)

    Mann, Megan A; Bottomley, Lawrence A

    2015-09-01

    The theory for cyclic square wave voltammetry of surface-confined quasireversible electrode reactions is presented and experimentally verified. Theoretical voltammograms were calculated following systematic variation of empirical parameters to assess their impact on the shape of the voltammogram. From the trends obtained, diagnostic criteria for this mechanism were deduced. These criteria were experimentally confirmed using two well-established surface-confined analytes. When properly applied, these criteria will enable non-experts in voltammetry to assign the electrode reaction mechanism and accurately measure electrode reaction kinetics.

  17. Cathodic adsorptive stripping square-wave voltammetry of the anti-inflammatory drug meloxicam.

    Science.gov (United States)

    Radi, A E; Ghoneim, M; Beltagi, A

    2001-10-01

    The adsorptive behavior of the anti-inflammatory drug meloxicam was studied by cyclic, differentia-pulse and square-wave voltammetry on a hanging mercury drop electrode (HMDE). The drug was accumulated at HMDE and a well-defined stripping peak current was obtained at -1.42 V vs. Ag/AgCl (saturated KCl) electrode in acetate buffer solution (pH 5.0). A voltammetric procedure was developed for the determination of meloxicam using square-wave cathodic adsorptive stripping voltammetry (SW-CASV). The optimum working conditions for the determination of the drug were established. The analysis of meloxicam in human plasma was carried out satisfactorily.

  18. Italian University Students and Digital Technologies: Some Results from a Field Research

    Science.gov (United States)

    Ferri, Paolo; Cavalli, Nicola; Costa, Elisabetta; Mangiatordi, Andrea; Mizzella, Stefano; Pozzali, Andrea; Scenini, Francesca

    Developments in information and communication technologies have raised the issue of how a kind of intergenerational digital divide can take place between "digital natives" and "digital immigrants". This can in turn have important consequences for the organization of educative systems. In this paper we present the result of a research performed during the course of 2008 to study how university students in Italy make use of digital technologies. The methodology was based on a mix of quantitative and qualitative approaches. A survey research was done, on a sample of 1186 students of the University of Milan-Bicocca, based on a questionnaire administrated through the Intranet of the University. A series of focus groups and in depth interviews with students, parents, and new media experts was furthermore performed. The results are consistent with the presence of a strong intergenerational divide. The implications of the results for the future organization of educative systems are discussed in the paper.

  19. Integrating the results of user research into medical device development: insights from a case study.

    Science.gov (United States)

    Martin, Jennifer L; Barnett, Julie

    2012-07-19

    It is well established that considering users is an important aspect of medical device development. However it is also well established that there are numerous barriers to successfully conducting user research and integrating the results into product development. It is not sufficient to simply conduct user research, it must also be effectively integrated into product development. A case study of the development of a new medical imaging device was conducted to examine in detail how users were involved in a medical device development project. Two user research studies were conducted: a requirements elicitation interview study and an early prototype evaluation using contextual inquiry. A descriptive in situ approach was taken to investigate how these studies contributed to the product development process and how the results of this work influenced the development of the technology. Data was collected qualitatively through interviews with the development team, participant observation at development meetings and document analysis. The focus was on investigating the barriers that exist to prevent user data from being integrated into product development. A number of individual, organisational and system barriers were identified that functioned to prevent the results of the user research being fully integrated into development. The user and technological aspects of development were seen as separate work streams during development. The expectations of the developers were that user research would collect requirements for the appearance of the device, rather than challenge its fundamental concept. The manner that the user data was communicated to the development team was not effective in conveying the significance or breadth of the findings. There are a range of informal and formal organisational processes that can affect the uptake of user data during medical device development. Adopting formal decision making processes may assist manufacturers to take a more integrated and

  20. Methods of Science Investigation Part 2: Results of Implementation of a Curriculum Fostering Original Scientific Research

    Science.gov (United States)

    Danch, J. M.

    2008-12-01

    Originally designed to allow secondary students with special needs to participate in original scientific research, the Methods of Science Curriculum was piloted in 2008. Students participating included those with special needs, English language learners, and the general population. Students were incrementally graduated from traditional inquiry activities towards authentic student-generated research projects. Students were evaluated via class work grades, an in-school symposium and a pre/post test. 100 percent of participants successfully completed and presented their original research. The pre/post evaluation demonstrated improvement for 91 percent of participants. An unanticipated result was the performance and growth of English language learners, possibly because of the emphasis on the creative and active process of science rather than vocabulary. A teacher-training program is being developed for expansion of the curriculum to additional schools in 2009.

  1. Higher education and curriculum innovation: results of an institutional network research

    Directory of Open Access Journals (Sweden)

    Martha Maria Prata-Linhares

    2013-06-01

    Full Text Available In this article we share the paths of an investigation carried out by a group of researchers from different Brazilian universities (FORPEC, which, based on the results of the investigation, built a network of information and research involving various education institutions. While describing this group’s pathway, the text presents innovating experiences of curriculums in higher education which provided important and significant pedagogic changes in their projects. During the period of investigation, 6 (six projects of university courses with innovation proposals were brought up and analyzed. This analysis allowed for the elaboration of innovation concepts for Higher Education, identify active innovating methodologies, create and implant innovative projects in Higher Education, as well as give the start off to investigation concerning the development of the docents integrating the innovating curricular projects. The groups’ pathway in itself may be considered an innovative research project.

  2. Research progress in muscle-derived stem cells Literature retrieval results based on international database

    Institute of Scientific and Technical Information of China (English)

    Li Zhang; Wei Wang

    2012-01-01

    OBJECTIVE: To identify global research trends of muscle-derived stem cells (MDSCs) using a bibliometric analysis of the Web of Science, Research Portfolio Online Reporting Tools of the National Institutes of Health (NIH), and the Clinical Trials registry database (ClinicalTrials.gov). DATA RETRIEVAL: We performed a bibliometric analysis of data retrievals for MDSCs from 2002 to 2011 using the Web of Science, NIH, and ClinicalTrials.gov. MAIN OUTCOME MEASURES: (1) Type of literature; (2) annual publication output; (3) distribution according to journals; (4) distribution according to country; (5) distribution according to institution; (6) top cited authors over the last 10 years; (7) projects financially supported by the NIH; and (8) clinical trials registered.RESULTS: (1) In all, 802 studies on MDSCs appeared in the Web of Science from 2002 to 2011, almost half of which derived from American authors and institutes. The number of studies on MDSCs has gradually increased over the past 10 years. Most papers on MDSCs appeared in journals with a particular focus on cell biology research, such as Experimental Cell Research, Journal of Cell Science, and PLoS One. (2) Eight MDSC research projects have received over US$6 billion in funding from the NIH. The current project led by Dr. Johnny Huard of the University of Pittsburgh-"Muscle-Based Tissue Engineering to Improve Bone Healing"-is supported by the NIH. Dr. Huard has been the most productive and top-cited author in the field of gene therapy and adult stem cell research in the Web of Science over last 10 years. (3) On ClinicalTrials.gov, "Muscle Derived Cell Therapy for Bladder Exstrophy Epispadias Induced Incontinence" Phase 1 is registered and sponsored by Johns Hopkins University and has been led by Dr. John P. Gearhart since November 2009.CONCLUSION: From our analysis of the literature and research trends, we found that MDSCs may offer further benefits in regenerative medicine.

  3. Nitrite detection in meat products samples by square-wave voltammetry at a new single walled carbon naonotubes--myoglobin modified electrode.

    Science.gov (United States)

    Turdean, Graziella L; Szabo, Gabriella

    2015-07-15

    A new modified electrode was realized in a simple way, consisting by the immobilization of a myoglobin (My) - single walled carbon nanotubes (SWCNT) mixture on the surface of a graphite electrode with a Nafion film. The cyclic voltammetry investigations realized with the obtained electrode (G/My-SWCNT/Nafion) showed a voltammetric signal due to a one-step redox reaction of the surface-confined myoglobin, in a deaerated 0.1 M phosphate buffer, pH 7. Also, the G/My-SWCNT/Nafion modified electrode demonstrated a great potential for the analytical determination of nitrite ions by square-wave voltammetry and an alternative for the already existing methods. The use of the sensor for the detection of nitrite ions in samples of meat products leads to comparable results with those obtained with the standard Griess spectrophotometric assay (ISO 2918/1975), proving the suitability of using immobilized myoglobin as electrocatalyst in the nitrite reduction process.

  4. The ANGWIN Antarctic Research Program: First Results on Coordinated Trans-Antarctic Gravity Wave Measurements

    Science.gov (United States)

    Taylor, M. J.; Pautet, P. D.; Zhao, Y.; Nakamura, T.; Ejiri, M. K.; Murphy, D. J.; Moffat-Griffin, T.; Kavanagh, A. J.; Takahashi, H.; Wrasse, C. M.

    2014-12-01

    ANGWIN (ANrctic Gravity Wave Instrument Network) is a new "scientist driven" research program designed to develop and utilize a network of Antarctic atmospheric gravity wave observatories, operated by different nations working together in a spirit of close scientific collaboration. Our research plan has brought together colleagues from several international institutions, all with a common goal to better understand the large "continental-scale" characteristics and impacts of gravity waves on the Mesosphere and Lower Thermosphere (MLT) environment over Antarctica. ANGWIN combines complementary measurements obtained using new and existing aeronomy instrumentation with new modeling capabilities. To date, our activities have focused on developing coordinated airglow image data of gravity waves in the MLT region at the following sites: McMurdo (US), Syowa (Japan), Davis (Australia), Halley (UK), Rothera (UK), and Comandante Ferraz (Brazil). These are all well-established international research stations that are uniformly distributed around the continental perimeter, and together with ongoing measurements at South Pole Station they provide unprecedented coverage of the Antarctic gravity wave field and its variability during the extended polar winter season. This presentation introduces the ANGWIN program and research goals, and presents first results on trans-Antarctic wave propagation using coordinated measurements during the winter season 2011. We also discuss future plans for the development of this exciting program for Antarctic research.

  5. Robotic voltammetry with carbon nanotube-based sensors: a superb blend for convenient high-quality antimicrobial trace analysis

    Directory of Open Access Journals (Sweden)

    Theanponkrang S

    2015-01-01

    Full Text Available Somjai Theanponkrang,1,2 Wipa Suginta,2,3 Helge Weingart,4 Mathias Winterhalter,4 Albert Schulte1,2 1School of Chemistry, 2Biochemistry–Electrochemistry Research Unit, Institute of Science, 3School of Biochemistry, Suranaree University of Technology, Nakhon Ratchasima, Thailand; 4Life Sciences, School of Engineering and Science, Jacobs University Bremen, Bremen, Germany Abstract: A new automated pharmacoanalytical technique for convenient quantification of redox-active antibiotics has been established by combining the benefits of a carbon nanotube (CNT sensor modification with electrocatalytic activity for analyte detection with the merits of a robotic electrochemical device that is capable of sequential nonmanual sample measurements in 24-well microtiter plates. Norfloxacin (NFX and ciprofloxacin (CFX, two standard fluoroquinolone antibiotics, were used in automated calibration measurements by differential pulse voltammetry (DPV and accomplished were linear ranges of 1–10 µM and 2–100 µM for NFX and CFX, respectively. The lowest detectable levels were estimated to be 0.3±0.1 µM (n=7 for NFX and 1.6±0.1 µM (n=7 for CFX. In standard solutions or tablet samples of known content, both analytes could be quantified with the robotic DPV microtiter plate assay, with recoveries within ±4% of 100%. And recoveries were as good when NFX was evaluated in human serum samples with added NFX. The use of simple instrumentation, convenience in execution, and high effectiveness in analyte quantitation suggest the merger between automated microtiter plate voltammetry and CNT-supported electrochemical drug detection as a novel methodology for antibiotic testing in pharmaceutical and clinical research and quality control laboratories. Keywords: antibiotics, electroanalysis, automation, microtiter plates, pharmaceutical screening, pharmacoanalytics

  6. Detailed analysis of the electron-transfer properties of azurin adsorbed on graphite electrodes using DC and large-amplitude Fourier transformed AC voltammetry.

    Science.gov (United States)

    Fleming, Barry D; Zhang, Jie; Elton, Darrell; Bond, Alan M

    2007-09-01

    The analysis of dc cyclic voltammograms of surface-confined metalloproteins is complicated by large background currents, significant ohmic iRu drop, and frequency dispersion related to protein and electrode surface inhomogeneity. The use of large-amplitude Fourier transform ac voltammetry for the quantification of the electron-transfer properties of a thin film of redox-active protein azurin adsorbed onto edge-plane, basal-plane, and highly oriented pyrolytic graphite electrode surfaces has been evaluated and compared to results obtained by dc cyclic voltammetry. In principle, it has been established that fourth and higher harmonic sine-wave data are ideally suited for analysis of electron-transfer processes as they are almost completely devoid of background capacitance current contributions. However, uncompensated resistance has a higher impact on these components, as is the case with fast scan rate dc techniques, so strategies to include this term in the simulations have been investigated. Application of recommended strategies for the evaluation of the electron-transfer properties of azurin adsorbed onto three forms of graphite, each having different background or uncompensated resistance values, is described and compared to results obtained by traditionally used forms of cyclic voltammetry. The electron-transfer rate constant, k0', of azurin at a highly oriented pyrolytic graphite electrode surface was approximately 250 s(-1), compared with > or =1000 s(-1) at edge-plane and basal-plane graphite electrodes. The significantly lower k0' value found at the highly oriented pyrolytic graphite electrode was related to the relatively low level of edge-plane defect sites present at the surface of this electrode. However, analysis of high ac harmonics suggests that frequency dispersion is substantial at all electrode surfaces. Such effects in these diffusionless situations are significantly enhanced relative to solution-phase voltammetry, where overlay of diffusion

  7. Development of Distributed Research Center for monitoring and projecting regional climatic and environmental changes: first results

    Science.gov (United States)

    Gordov, Evgeny; Shiklomanov, Alexander; Okladinikov, Igor; Prusevich, Alex; Titov, Alexander

    2016-04-01

    Description and first results of the cooperative project "Development of Distributed Research Center for monitoring and projecting of regional climatic and environmental changes" recently started by SCERT IMCES and ESRC UNH are reported. The project is aimed at development of hardware and software platform prototype of Distributed Research Center (DRC) for monitoring and projecting regional climatic and environmental changes over the areas of mutual interest and demonstration the benefits of such collaboration that complements skills and regional knowledge across the northern extratropics. In the framework of the project, innovative approaches of "cloud" processing and analysis of large geospatial datasets will be developed on the technical platforms of two U.S. and Russian leading institutions involved in research of climate change and its consequences. Anticipated results will create a pathway for development and deployment of thematic international virtual research centers focused on interdisciplinary environmental studies by international research teams. DRC under development will comprise best features and functionality of earlier developed by the cooperating teams' information-computational systems RIMS (http://rims.unh.edu) and CLIMATE(http://climate.scert.ru/), which are widely used in Northern Eurasia environment studies. The project includes several major directions of research (Tasks) listed below. 1. Development of architecture and defining major hardware and software components of DRC for monitoring and projecting of regional environmental changes. 2. Development of an information database and computing software suite for distributed processing and analysis of large geospatial data hosted at ESRC and IMCES SB RAS. 3. Development of geoportal, thematic web client and web services providing international research teams with an access to "cloud" computing resources at DRC; two options will be executed: access through a basic graphical web browser and

  8. Results of S5 CH tests with an ARL (Aerospace Research Laboratory) cascade

    Science.gov (United States)

    Fourmaux, A.

    1984-01-01

    As part of a research agreement between Iowa State University of Science and Technology (ISU) and ONERA, a blade cascade designed and already tested in the United States was manufactured and tested in France. The ONERA cascade wind tunnel and mock-up are described. Attention is focused on defining the upstream conditions of the cascade. Experimental results are presented, as well as comparisons with tests conducted by Detroit Diesel Allison (DDA) in the United States.

  9. Solid State Batteries, Literature Survey, Analysis of Pertinent Results and Prospective for Further Research.

    Science.gov (United States)

    1983-12-01

    Pertinent Results and p ective JAN - DEC 983 for further research. 6. PERFORMING GRG. REPORT NUMBER 7. AUTHOR(&) 8. CONTRACT UR GRANT NUMBER9) -"- M. Balka...USAwiDSC-UK JAN -. DEC 1983 __._ Dox 65 I1. NUMBEOF PAGES ___.._ " fl_’ [ _ __ _-__ __ __ _ _" 14. MONITORINc, AGENCY NA/E & ADDRESS(II dlfltent from...properties and decrease first order transition temperatures have been used ( Bazan et al,1982). Nevertheless it is a truism that the ideal silver

  10. Clinical practice of image-guided spine radiosurgery - results from an international research consortium

    Directory of Open Access Journals (Sweden)

    Guckenberger Matthias

    2011-12-01

    Full Text Available Abstract Background Spinal radiosurgery is a quickly evolving technique in the radiotherapy and neurosurgical communities. However, the methods of spine radiosurgery have not been standardized. This article describes the results of a survey about the methods of spine radiosurgery at five international institutions. Methods All institutions are members of the Elekta Spine Radiosurgery Research Consortium and have a dedicated research and clinical focus on image-guided radiosurgery. The questionnaire consisted of 75 items covering all major steps of spine radiosurgery. Results Strong agreement in the methods of spine radiosurgery was observed. In particular, similarities were observed with safety and quality assurance playing an important role in the methods of all institutions, cooperation between neurosurgeons and radiation oncologists in case selection, dedicated imaging for target- and organ-at-risk delineation, application of proper safety margins for the target volume and organs-at-risk, conformal planning and precise image-guided treatment delivery, and close clinical and radiological follow-up. In contrast, three major areas of uncertainty and disagreement were identified: 1 Indications and contra-indications for spine radiosurgery; 2 treatment dose and fractionation and 3 tolerance dose of the spinal cord. Conclusions Results of this study reflect the current practice of spine radiosurgery in large academic centers. Despite close agreement was observed in many steps of spine radiosurgery, further research in form of retrospective and especially prospective studies is required to refine the details of spinal radiosurgery in terms of safety and efficacy.

  11. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays

    Science.gov (United States)

    Guetterman, Timothy C.; Fetters, Michael D.; Creswell, John W.

    2015-01-01

    PURPOSE Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. METHODS We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. RESULTS The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. CONCLUSIONS Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. PMID:26553895

  12. NASA Glenn Icing Research Tunnel: 2012 Cloud Calibration Procedure and Results

    Science.gov (United States)

    VanZante, Judith Foss; Ide, Robert F.; Steen, Laura E.

    2012-01-01

    In 2011, NASA Glenn s Icing Research Tunnel underwent a major modification to it s refrigeration plant and heat exchanger. This paper presents the results of the subsequent full cloud calibration. Details of the calibration procedure and results are presented herein. The steps include developing a nozzle transfer map, establishing a uniform cloud, conducting a drop sizing calibration and finally a liquid water content calibration. The goal of the calibration is to develop a uniform cloud, and to build a transfer map from the inputs of air speed, spray bar atomizing air pressure and water pressure to the output of median volumetric droplet diameter and liquid water content.

  13. Pediatric Cancer Genetics Research and an Evolving Preventive Ethics Approach for Return of Results after Death of the Subject.

    Science.gov (United States)

    Scollon, Sarah; Bergstrom, Katie; McCullough, Laurence B; McGuire, Amy L; Gutierrez, Stephanie; Kerstein, Robin; Parsons, D Williams; Plon, Sharon E

    2015-01-01

    The return of genetic research results after death in the pediatric setting comes with unique complexities. Researchers must determine which results and through which processes results are returned. This paper discusses the experience over 15 years in pediatric cancer genetics research of returning research results after the death of a child and proposes a preventive ethics approach to protocol development in order to improve the quality of return of results in pediatric genomic settings.

  14. Exploring risk communication - results of a research project focussed on effectiveness evaluation

    Science.gov (United States)

    Charrière, Marie; Bogaard, Thom; Junier, Sandra; Mostert, Erik

    2016-04-01

    The need for effective science communication and outreach efforts is widely acknowledged in the academic community. In the field of Disaster Risk Reduction, the importance of communication is clearly stressed, e.g. in the newly adopted Sendai Framework for Disaster Risk Reduction 2015-2030 (under the 1st priority of action: understanding disaster risk). Consequently, we see increasing risk communication activities. However, the effectiveness of these activities is rarely evaluated. To address this gap, several research activities were conducted in the context of the Marie Curie Initial Training Network "Changes", the results of which we will present and discuss. First, results of a literature review show, among others, that research on effectiveness is mainly focussed on the assessment of users' needs and their ability to understand the content, rather than on the final impact of the risk communication efforts. Moreover, lab-environment research is more often undertaken than assessment of real communication efforts. Second, a comparison between perceptions of risk managers and the general public of risk communication in a French Alps Valley highlighted a gap between the two groups in terms of amount of information needed (who wants more), the important topics to address (what) and the media to use (how). Third, interviews with developers of smartphone applications for disseminating avalanche risk information showed a variety of current practices and the absence of measurements of real their effectiveness. However, our analysis allowed identifying good practices that can be an inspiration for risk communication related to other hazards. Fourth, an exhibition has been set up following a collaborative approached based on stakeholder engagement. Using a pre/post-test design, the immediate impact of the exhibition, which aimed at increasing the risk awareness of the population (Ubaye Valley, France), was measured. The data obtained suggests that visiting the exhibition

  15. Theory of linear sweep voltammetry with diffuse charge: Unsupported electrolytes, thin films, and leaky membranes

    Science.gov (United States)

    Yan, David; Bazant, Martin Z.; Biesheuvel, P. M.; Pugh, Mary C.; Dawson, Francis P.

    2017-03-01

    Linear sweep and cyclic voltammetry techniques are important tools for electrochemists and have a variety of applications in engineering. Voltammetry has classically been treated with the Randles-Sevcik equation, which assumes an electroneutral supported electrolyte. In this paper, we provide a comprehensive mathematical theory of voltammetry in electrochemical cells with unsupported electrolytes and for other situations where diffuse charge effects play a role, and present analytical and simulated solutions of the time-dependent Poisson-Nernst-Planck equations with generalized Frumkin-Butler-Volmer boundary conditions for a 1:1 electrolyte and a simple reaction. Using these solutions, we construct theoretical and simulated current-voltage curves for liquid and solid thin films, membranes with fixed background charge, and cells with blocking electrodes. The full range of dimensionless parameters is considered, including the dimensionless Debye screening length (scaled to the electrode separation), Damkohler number (ratio of characteristic diffusion and reaction times), and dimensionless sweep rate (scaled to the thermal voltage per diffusion time). The analysis focuses on the coupling of Faradaic reactions and diffuse charge dynamics, although capacitive charging of the electrical double layers is also studied, for early time transients at reactive electrodes and for nonreactive blocking electrodes. Our work highlights cases where diffuse charge effects are important in the context of voltammetry, and illustrates which regimes can be approximated using simple analytical expressions and which require more careful consideration.

  16. Differential Cyclic Voltammetry - a Novel Technique for Selective and Simultaneous Detection using Redox Cycling Based Sensors

    NARCIS (Netherlands)

    Odijk, M.; Wiedemair, J.; Megen, M.J.J; Olthuis, W.; Berg, van den A.

    2010-01-01

    Redox cycling (RC) is an effect that is used to amplify electrochemical signals. However, traditional techniques such as cyclic voltammetry (CV) do not provide clear insight for a mixture of multiple redox couples while RC is applied. Thus, we have developed a new measurement technique which deliver

  17. Characterization of Fe implanted yttria-stabilized zirconia by cyclic voltammetry

    NARCIS (Netherlands)

    Hassel, van B.A.; Burggraaf, A.J.

    1992-01-01

    The technique of cyclic voltammetry has been applied to study reduction and oxidation phenomena which are observed at low oxygen partial pressures during steady state current-overpotential measurements of the Au, O2(g)/Fe implanted yttria-stabilized zirconia interface. The redox potential (EO) of th

  18. Differential Cyclic Voltammetry - a Novel Technique for Selective and Simultaneous Detection using Redox Cycling Based Sensors

    NARCIS (Netherlands)

    Odijk, Mathieu; Wiedemair, Justyna; van Megen, M.J.J.; Olthuis, Wouter; van den Berg, Albert

    2010-01-01

    Redox cycling (RC) is an effect that is used to amplify electrochemical signals. However, traditional techniques such as cyclic voltammetry (CV) do not provide clear insight for a mixture of multiple redox couples while RC is applied. Thus, we have developed a new measurement technique which

  19. Development and Use of a Cyclic Voltammetry Simulator to Introduce Undergraduate Students to Electrochemical Simulations

    Science.gov (United States)

    Brown, Jay H.

    2015-01-01

    Cyclic voltammetry (CV) is a popular technique for the study of electrochemical mechanisms because the method can provide useful information on the redox couple. The technique involves the application of a potential ramp on an unstirred solution while the current is monitored, and then the ramp is reversed for a return sweep. CV is sometimes…

  20. Characterization of Fe implanted yttria-stabilized zirconia by cyclic voltammetry

    NARCIS (Netherlands)

    van Hassel, B.A.; van Hassel, B.A.; Burggraaf, Anthonie; Burggraaf, A.J.

    1992-01-01

    The technique of cyclic voltammetry has been applied to study reduction and oxidation phenomena which are observed at low oxygen partial pressures during steady state current-overpotential measurements of the Au, O2(g)/Fe implanted yttria-stabilized zirconia interface. The redox potential (EO) of

  1. Cyclic Voltammetry Simulations with DigiSim Software: An Upper-Level Undergraduate Experiment

    Science.gov (United States)

    Messersmith, Stephania J.

    2014-01-01

    An upper-division undergraduate chemistry experiment is described which utilizes DigiSim software to simulate cyclic voltammetry (CV). Four mechanisms were studied: a reversible electron transfer with no subsequent or proceeding chemical reactions, a reversible electron transfer followed by a reversible chemical reaction, a reversible chemical…

  2. Polymyxin-coated Au and carbon nanotube electrodes for stable [NiFe]-hydrogenase film voltammetry.

    NARCIS (Netherlands)

    Hoeben, F.J.M.; Heller, I.; Albracht, S.P.J.; Dekker, C.; Lemay, S.G.; Heering, H.A.

    2008-01-01

    We report on the use of polymyxin (PM), a cyclic cationic lipodecapeptide, as an electrode modifier for studying protein film voltammetry (PFV) on Au and single-walled carbon nanotube (SWNT) electrodes. Pretreating the electrodes with PM allows for the subsequent immobilization of an active

  3. Polymyxin-coated Au and carbon nanotube electrodes for stable [NiFe]-hydrogenase film voltammetry.

    NARCIS (Netherlands)

    Hoeben, F.J.M.; Heller, I.; Albracht, S.P.J.; Dekker, C.; Lemay, S.G.; Heering, H.A.

    2008-01-01

    We report on the use of polymyxin (PM), a cyclic cationic lipodecapeptide, as an electrode modifier for studying protein film voltammetry (PFV) on Au and single-walled carbon nanotube (SWNT) electrodes. Pretreating the electrodes with PM allows for the subsequent immobilization of an active submonol

  4. Development and Use of a Cyclic Voltammetry Simulator to Introduce Undergraduate Students to Electrochemical Simulations

    Science.gov (United States)

    Brown, Jay H.

    2015-01-01

    Cyclic voltammetry (CV) is a popular technique for the study of electrochemical mechanisms because the method can provide useful information on the redox couple. The technique involves the application of a potential ramp on an unstirred solution while the current is monitored, and then the ramp is reversed for a return sweep. CV is sometimes…

  5. The Rise of Voltammetry: From Polarography to the Scanning Electrochemical Microscope

    Science.gov (United States)

    Bard, Allen J.

    2007-01-01

    The drooping mercury electrode (DME) was previously used to carry out electrochemical experiments but invention of polarography technique changed this. Voltammetry with DME was given the term polarography and are used in measurement of current as a function of potential at small electrodes.

  6. Lead-Testing Service to Elementary and Secondary Schools Using Anodic Stripping Voltammetry

    Science.gov (United States)

    Goebel, Amanda; Vos, Tracy; Louwagie, Anne; Lundbohm, Laura; Brown, Jay H.

    2004-01-01

    The undergraduate chemistry club of the Southwest Minnesota State University offers assistance in lead-testing through the anodic stripping voltammetry (ASV) technique to elementary and secondary schools. Emphasis is given to this community service activity, which has increased club membership, and promoted discussion of water quality problems in…

  7. Determination of bosentan in pharmaceutical preparations by linear sweep, square wave and differential pulse voltammetry methods.

    Science.gov (United States)

    Atila, Alptug; Yilmaz, Bilal

    2015-01-01

    In this study, simple, fast and reliable cyclic voltammetry (CV), linear sweep voltammetry (LSV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV) methods were developed and validated for determination of bosentan in pharmaceutical preparations. The proposed methods were based on electrochemical oxidation of bosentan at platinum electrode in acetonitrile solution containing 0.1 M TBACIO4. The well-defined oxidation peak was observed at 1.21 V. The calibration curves were linear for bosentan at the concentration range of 5-40 µg/mL for LSV and 5-35 µg/mL for SWV and DPV methods, respectively. Intra- and inter-day precision values for bosentan were less than 4.92, and accuracy (relative error) was better than 6.29%. The mean recovery of bosentan was 100.7% for pharmaceutical preparations. No interference was found from two tablet excipients at the selected assay conditions. Developed methods in this study are accurate, precise and can be easily applied to Tracleer and Diamond tablets as pharmaceutical preparation.

  8. Kinetic Diversity of Striatal Dopamine: Evidence from a Novel Protocol for Voltammetry.

    Science.gov (United States)

    Walters, Seth H; Robbins, Elaine M; Michael, Adrian C

    2016-05-18

    In vivo voltammetry reveals substantial diversity of dopamine kinetics in the rat striatum. To substantiate this kinetic diversity, we evaluate the temporal distortion of dopamine measurements arising from the diffusion-limited adsorption of dopamine to voltammetric microelectrodes. We validate two mathematical procedures for correcting adsorptive distortion, both of which substantiate that dopamine's apparent kinetic diversity is not an adsorption artifact.

  9. Adsorptive Stripping Voltammetry of Environmental Indicators: Determination of Zinc in Algae

    Science.gov (United States)

    Collado-Sanchez, C.; Hernandez-Brito, J. J.; Perez-Pena, J.; Torres-Padron, M. E.; Gelado-Caballero, M. D.

    2005-01-01

    A method for sample preparation and for the determination of average zinc content in algae using adsorptive stripping voltammetry are described. The students gain important didactic advantages through metal determination in environmental matrices, which include carrying out clean protocols for sampling and handling, and digesting samples using…

  10. Cyclic Voltammetry Simulations with DigiSim Software: An Upper-Level Undergraduate Experiment

    Science.gov (United States)

    Messersmith, Stephania J.

    2014-01-01

    An upper-division undergraduate chemistry experiment is described which utilizes DigiSim software to simulate cyclic voltammetry (CV). Four mechanisms were studied: a reversible electron transfer with no subsequent or proceeding chemical reactions, a reversible electron transfer followed by a reversible chemical reaction, a reversible chemical…

  11. Results of research in the area of nanotechnologies and nanomaterials. Part 2

    Directory of Open Access Journals (Sweden)

    KARPOV Alexey Ivanovich

    2014-04-01

    Full Text Available To popularize scientific achievements in construction the main results of Russian and foreign scientists’ research are published in the form of abstract. Within the investigation «Obtaining and research of physical and chemical properties of nanosized system nickel–copper» experimentally proved model of synthesis of nanosized powders of system nickel–copper based on the method of reduction of metal salts from water solution has been offered; optimal conditions for obtaining radiographic pure powders have been determined. The paper also deals with conditions for obtaining and phase composition of mixed nickel and copper hydroxides including those which are stable when stored in wet conditions. The copper hydroxide stabilization method has been proposed. The practical value of performed investigation «Research of electron structure functionalized carbon nanotubes by spectographic methods with synchronous radiation» is that it developed one of the areas of physical chemistry: complex research of electron structure of carbon nanotubes including functionalized ones was carried out by the method of experimental (spectographic with synchrotron radiation of different energies and theoretical methods; the general methods of the modern applied plasmonics aimed at identification of characteristics of defects formation in carbon nanosystems of low dimension have been developed.

  12. Ecological research at the offshore windfarm alpha ventus. Challenges, results and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Beiersdorf, Anika; Wollny-Goerke, Katrin (eds.)

    2014-07-01

    At present and over the next few years, large-scale windfarms are being installed far off the coast of Germany in the North and Baltic Sea, making a major contribution to electricity generation from renewable energy sources. One of the German government's aims is to ensure the environmentally sound and sustainable development of offshore wind energy. Germany's first offshore test site, alpha ventus, was therefore accompanied from the construction phase to the first years of operation by an intensive environmental research programme, the StUKplus project, financed by the Federal Ministry for the Environment, Nature Conservation and Nuclear Safety and coordinated by the Federal Maritime and Hydrographic Agency. Marine and ecological aspects have been researched there for more than five years to improve the level of knowledge about the ecological impacts of offshore windfarms. This book provides a broad, richly illustrated overview of applied and new research methods and monitoring techniques. It summarises the key research findings on the impacts on benthic communities, fish, marine mammals and birds, also taking into account underwater sound and sediment measurements. Interpreting the results in the sense of lessons learned, new challenges and perspectives are discussed for future sustainable offshore development in German waters.

  13. Electrochemical determination of closantel in the commercial formulation by square-wave adsorptive stripping voltammetry.

    Science.gov (United States)

    Brycht, Mariola; Nosal-Wiercińska, Agnieszka; Sipa, Karolina; Rudnicki, Konrad; Skrzypek, Sławomira

    2017-01-01

    In this paper, the square-wave adsorptive stripping voltammetric (SWAdSV) determination of the veterinary drug closantel using a renewable silver amalgam film electrode (Hg(Ag)FE) is presented. As observed in SWAdSV, closantel provided one well-shaped reduction peak suitable for analytical purposes at potential ca. -1.4 V in the Britton-Robinson (B-R) buffer at pH 7.0. At optimal conditions, the SWAdSV response of Hg(Ag)FE for determining closantel was linear over two concentration ranges of 5.0 × 10(-8) to 2.0 × 10(-7) mol dm(-3) and 2.0 × 10(-7) to 1.2 × 10(-6) mol dm(-3) with a detection limit of 1.1 × 10(-8) mol dm(-3). In addition, a relevance of the developed SWAdSV method was successfully verified by the quantitative analysis of closantel in the commercial formulation Closamectin Pour-On with satisfactory results (RSD = 5.8%, recovery = 101.8%). The results showed that the developed procedure can be adequate for screening purposes. Also, the electrochemical behavior of closantel was characterized by cyclic voltammetry, and it was found that closantel exhibited a quasi-reversible behavior with cathodic peak on the forward scan at ca. -1.4 V and anodic peak on the reverse scan at ca. -1.35 V vs. Ag/AgCl in B-R buffer, pH 7.0. As the obtained results showed that the electrode mechanism of closantel is controlled by the adsorption, the effect of adsorption was studied using the electrochemical impedance spectroscopy technique.

  14. Results of research in the area of nanotechnologies and nanomaterials. Part 4

    Directory of Open Access Journals (Sweden)

    KARPOV Alexey Ivanovich

    2014-08-01

    Full Text Available To popularize scientific achievements in construction the main results of Russian and foreign scientists’ research are published in the form of abstract. Within the frame of the research «Nanocomposite cabel elastrons based on polyvinylchloride and aluminum silicate» new nanocomposite materials based on polyvinylchloride elastron with organomodified montmorillonite and combinations of it with non-halogen fire flame retardant have been developed. The experiment shows that carbamide-containing organoclay is the efficient filler of polyvinylchloride elastron. The receipts and production method for new polymer nanocomposites based on PVC elastron and organomodified montmorillonite have been designed. The paper provides information on the methods to obtain nanodimensional natural fillers; principles for choosing organomodifiers and their influence on the quality of nanodimensional flaked silicate fillers; application efficiency of organoclays when modifying properties of polymer materials. All that makes the results of the research to be very useful for specialists engaged into the area of filler manufacture, creation and processing of polymer composite material and designing products of them. Specialists can use published materials in their scientific and practical activities.

  15. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays.

    Science.gov (United States)

    Guetterman, Timothy C; Fetters, Michael D; Creswell, John W

    2015-11-01

    Mixed methods research is becoming an important methodology to investigate complex health-related topics, yet the meaningful integration of qualitative and quantitative data remains elusive and needs further development. A promising innovation to facilitate integration is the use of visual joint displays that bring data together visually to draw out new insights. The purpose of this study was to identify exemplar joint displays by analyzing the various types of joint displays being used in published articles. We searched for empirical articles that included joint displays in 3 journals that publish state-of-the-art mixed methods research. We analyzed each of 19 identified joint displays to extract the type of display, mixed methods design, purpose, rationale, qualitative and quantitative data sources, integration approaches, and analytic strategies. Our analysis focused on what each display communicated and its representation of mixed methods analysis. The most prevalent types of joint displays were statistics-by-themes and side-by-side comparisons. Innovative joint displays connected findings to theoretical frameworks or recommendations. Researchers used joint displays for convergent, explanatory sequential, exploratory sequential, and intervention designs. We identified exemplars for each of these designs by analyzing the inferences gained through using the joint display. Exemplars represented mixed methods integration, presented integrated results, and yielded new insights. Joint displays appear to provide a structure to discuss the integrated analysis and assist both researchers and readers in understanding how mixed methods provides new insights. We encourage researchers to use joint displays to integrate and represent mixed methods analysis and discuss their value. © 2015 Annals of Family Medicine, Inc.

  16. Natural science research of the Bulgar fortified settlement site (preliminary results

    Directory of Open Access Journals (Sweden)

    Golyeva Alexandra A.

    2014-06-01

    Full Text Available The article presents the first results of the comprehensive scientific research conducted on the Bulgar fortified settlement site in 2011. Samples for analysis were selected in the form of series of vertical columns from excavation walls. The species of trees used in the construction, the composition of the mud bricks and the bonding mortar, as well as the genesis of individual cultural layers have been identified. It has been found out that the settlement development and functioning had been reciprocating in nature: periods of intense habitation of its individual sections were followed by short stages of desolation. In all investigated soil columns with the cultural layers there are streaks consisting solely of phytoliths and cuticle casts. A possible explanation of the phenomenon may be that the plot was covered with layers of manure of significant length and capacity. This conclusion is debatable and requires further research.

  17. Recent trends in published occupational cancer epidemiology research: results from a comprehensive review of the literature.

    Science.gov (United States)

    Raj, Priyanka; Hohenadel, Karin; Demers, Paul A; Zahm, Shelia Hoar; Blair, Aaron

    2014-03-01

    To assess trends in occupational cancer epidemiology research through a literature review of occupational health and epidemiology journals. Fifteen journals were reviewed from 1991 to 2009, and characteristics of articles that assessed the risk of cancer associated with an occupation, industry, or occupational exposure, were incorporated into a database. The number of occupational cancer epidemiology articles published annually declined in recent years (2003 onwards) in the journals reviewed. The number of articles presenting dose-response analyses increased over the review period, from 29% in the first 4 years of review to 49% in the last 4 years. There has been a decrease in the number of occupational cancer epidemiology articles published annually during the review period. The results of these articles help determine the carcinogenicity of workplace exposures and permissible exposure limits, both of which may be hindered with a decline in research. © 2013 Wiley Periodicals, Inc.

  18. Lab-on-a-Chip Sensor with Evaporated Bismuth Film Electrode for Anodic Stripping Voltammetry of Zinc

    Science.gov (United States)

    Kang, Wenjing; Pei, Xing; Yue, Wei; Bange, Adam; Heineman, William R.; Papautsky, Ian

    2013-01-01

    In this work, we report on the development of a lab-on-a-chip electrochemical sensor that uses an evaporated bismuth electrode to detect zinc using square wave anodic stripping voltammetry. The microscale electrochemical cell consists of a bismuth working electrode, an integrated silver/silver chloride reference electrode, and a gold auxiliary electrode. The sensor demonstrated linear response in 0.1 M acetate buffer at pH 6 with zinc concentrations ranging from 1 μM to 30 μM and a calculated detection limit of 60 nM. The sensor was also able to successfully detect zinc in a bovine serum extract and the results were verified with independent AAS measurements. These results demonstrate the advantageous qualities of this lab-on-a-chip electrochemical sensor for clinical applications, which include a small sample volume (μL scale), reduced cost, short response time and high accuracy at low concentrations of analyte. PMID:24436575

  19. Cyclic Voltammetry of Polysulfide (Thiokol) Prepolymers and Related Compounds

    Science.gov (United States)

    1983-12-01

    low scan rates suqges t that A and B are unstable and undergo chesical reactions on the cyclic voltametry time scale. A more detailed examination is...REPOR CYCLIC VOLTAq4ETRY OF POLYSIILF!OE (THIOKOL) PREPOLYMERS AND~ RELATED COMPODWS Waldemar Nazurek ThE UPrEDT STATES NATIONAL. CZTECMNNCAL...DEPARTMENT OF DEFENCE MATERIALS RESEARCH LABORATORIES REPORT MRL-R.911 CYCLIC VOLTAP,4ETRY OF POLYSULFIDE (THIOKOL) PREPOLYMERS AND RELATEn COMPOUNDS 𔃻

  20. Speciation study of aluminium in beverages by Competitive Ligand Exchange-Adsorptive Stripping Voltammetry.

    Science.gov (United States)

    Magnier, A; Fekete, V; Van Loco, J; Bolle, F; Elskens, M

    2014-05-01

    Competitive Ligand Exchange-Adsorptive Stripping Voltammetry (CLE-AdSV) was used for determining the speciation of aluminium in commonly consumed beverages (water, tea, infusion, coffee, orange juice, tomato juice, beer and red wine). Aluminium determination involves the adsorption of Al-complexes with the ligand cupferron onto a hanging mercury drop electrode. All samples were studied at pH 6.5 with an accumulation step at -0.60 V (all potential values in the paper are given versus the Ag/AgCl, [KCl]=3 M reference electrode) during 60 s, and a final cupferron concentration of 4 × 10(-4)M. These conditions were used to establish (i) the concentration of electro-labile aluminium, (ii) the range of ligand concentrations and (iii) the conditional stability constants of beverage samples using titration procedures. The results based on Ruzic plots were compared to computer simulation with Visual MINTEQ. This comparison suggests that labile monomeric Al-forms and soluble organic complexes of low molecular weight can be quantified by the CLE-AdSV procedure. Overall the relative uncertainties on the determination of the electro-active Al fraction and the complexing parameters, i.e., concentration and conditional stability constant of natural ligands in the samples, are less than 15%. Thanks to these results, information on Al bioavailability in beverages was collected and discussed. This study also illustrates the value of computer simulations when complex, time-consuming voltammetric techniques are applied. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Ethical considerations about reporting research results with potential for further stigmatization of undocumented immigrants.

    Science.gov (United States)

    Achkar, Jacqueline M; Macklin, Ruth

    2009-05-01

    A broad spectrum of infectious diseases is studied in vulnerable populations. However, ethical considerations of reporting research results that could increase stigmatization of socially marginalized and vulnerable populations are not often discussed in the medical literature, particularly not in the context of transmissible diseases. This article addresses ethical considerations that arose when one of us (J.M.A.) recently published the results of a study in Clinical Infectious Diseases that imply that undocumented persons are more likely to transmit tuberculosis than are documented foreign-born persons or persons born in the United States. These study results have the potential to further fuel the often fierce debate regarding undocumented immigrants in the United States. To our knowledge, such ethical considerations have not been discussed previously in the medical literature.

  2. Results of research in the area of nanotechnologies and nanomaterials. Part 5.

    Directory of Open Access Journals (Sweden)

    KARPOV Alexey Ivanovich

    2014-10-01

    Full Text Available To popularize scientific achievements in construction the main results of Russian and foreign scientists’ research are published in the form of abstract. These are main results of the research «Polymer construction nanocomposites based on polyvinylchloride»: technological recommendations on the use of multilayer carbon nanotubes, silicagel functionalized with the sulfur and silica sol in receipts of shape-moulded PVC-products for construction industry which allow increasing strength by 12–25%, thermal stability by 35–50% and decreasing melt viscosity (the factor increases 2–5 times; receipts and technology for production of high-filled construction composites based on PVC functionalized with silica sol and wood flour with population up to 68 mass.% when molding index is increased 12 times and thermal stability is increased by 60%. The specialists may be interested in the results of the following research: – I.S. Maeva «Modification of anhydride compositions with ultra- and nanodispersed additives»; – E.G. Chebotareva «Nanomodified composites of construction purpose with the use of epoxy resin»; – A.A. Volodchenko «Non-autoclave silicate materials with the use of natural nanodispersed raw materials»; – O.V. Popkova «Production and properties of metal-containing nanoparticles (Fe, Co, Ni, Zn, Ce, Cd, Pd, Ag, Mo, stabilized by nanodiamond of denotational synthesis and high pressure polyethylene»; – M.A. Fronya «Complex study of mechanical properties and structure of polymer composite materials with carbon modification fillers: nanotubes and ultradispersed diamonds»; – M.S. Babaeva «Production and study of nanoparticles of polymer-colloid complexes based on polymers of N,N-diallyl-N,N-chloride dimethylammonium and natrium dodecylsulfate». Published materials can be used by the specialists in their scientific and practical activities in construction, housing and communal services as well as in the joint economical

  3. Education in research: results of a survey commissioned by the research committee of the European Society of Radiology

    OpenAIRE

    ,

    2012-01-01

    Objectives The purpose of this investigation was to assess the current status of education in research in Europe with a view to making recommendations and improvements in the status of education in research for involved stakeholders. Methods A questionnaire concerning education in research in Europe was sent to the National Society representatives, to Subspecialty Societies and potentially interested ESR committees. Questions were posed to assess the current status and to explore a desired fu...

  4. Ala from Zeljin: Results of the recent research of folk mythology in Zupa

    Directory of Open Access Journals (Sweden)

    Todorović Ivica

    2011-01-01

    Full Text Available The paper presents the results of the recent ethnological research, conduced in Aleksandrovacka Zupa and other areas. In this paper, the emphasis has been placed on notions on mythical beings, i.e. alas and dragons, which in the context of the materials collected take up one of most prominent positions, indicating the specific nature of the micro-regional unit, but also a symbol of the local identity. Namely, there are recordings of numerous and extremely interesting variations of the myth and ideas on the ala from Zeljin which, as the definitely most exposed mythical entity, is certainly a Zupa-specific property.

  5. NASA Glenn Icing Research Tunnel: 2014 Cloud Calibration Procedure and Results

    Science.gov (United States)

    Van Zante, Judith F.; Ide, Robert F.; Steen, Laura E.; Acosta, Waldo J.

    2014-01-01

    The results of the December 2013 to February 2014 Icing Research Tunnel full icing cloud calibration are presented. The calibration steps included establishing a uniform cloud and conducting drop size and liquid water content calibrations. The goal of the calibration was to develop a uniform cloud, and to generate a transfer function from the inputs of air speed, spray bar atomizing air pressure and water pressure to the outputs of median volumetric drop diameter and liquid water content. This was done for both 14 CFR Parts 25 and 29, Appendix C ('typical' icing) and soon-to-be released Appendix O (supercooled large drop) conditions.

  6. MouldingSandDB – a modern database storing moulding sands properties research results

    Directory of Open Access Journals (Sweden)

    J. Jakubski

    2011-01-01

    Full Text Available The complexity of foundry processes requires the use of modern, advanced IT tools for optimization, storage and analysis of t echnicaldata. Properties of moulding and core sands that are collected in research laboratories, manufacturers, and finally in the foundries, are not in use later on. It seems important to create a database that will allow to use the results stored, along with the possibility of searching according to set criteria, adjusted to casting practice. This paper presents part of the database named „MouldingSandDB”, which allows to collect and search data for synthetic moulding sands.

  7. Variable conductance heat pipe technology. [research project resulting in heat pipe experiment on OAO-3 satellite

    Science.gov (United States)

    Anderson, W. T.; Edwards, D. K.; Eninger, J. E.; Marcus, B. D.

    1974-01-01

    A research and development program in variable conductance heat pipe technology is reported. The project involved: (1) theoretical and/or experimental studies in hydrostatics, (2) hydrodynamics, (3) heat transfer into and out of the pipe, (4) fluid selection, and (5) materials compatibility. The development, fabrication, and test of the space hardware resulted in a successful flight of the heat pipe experiment on the OAO-3 satellite. A summary of the program is provided and a guide to the location of publications on the project is included.

  8. Research result information for agriculture and environment. No.12; Nogyo kankyo kenkyu seika joho. 12

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-26

    Essential purposes of productivity improvement, which human being have desires in agriculture for a long time, can not be discussed without considering relations with the environment, nowadays. In these situations, significant investigations have been created among the researches in the agriculture and environment field in response to the requirements of the time. In this report, results of 41 main researches submitted to the agriculture and environment research promotion conference in FY 1995 are compiled. This field covers the environment and resource characterization, the agrioecology, and the environment assessment and control. The environment and resource characterization field includes studies on the micro-meteorological mechanism of desert expansion due to excess pasturage, the salt removal function of clays, and the protection of ground water quality by grassland. The agrioecology field includes studies on the antimicrobial substance contained in Glycyrrhiza glabra against the soil decease of potatoes caused by Streptomyces scabies and the new plant growth obstruction substance contained in Sphenoclea zeylanica. The environment assessment and control field includes studies on the producing district change prediction of main grains accompanied with global environmental change and the carbon balance in the ecosystem of farm lands and rice fields. This report includes a lot of noticeable papers. 103 figs., 24 tabs.

  9. Practices of Disciplinarity and Interdisciplinarity in Quebec Elementary Schools: Results of Twenty Years of Research

    Directory of Open Access Journals (Sweden)

    Yves Lenoir

    2006-12-01

    Full Text Available This article presents a synthesis of different research projects that have been carried out inthe province of Quebec, Canada over the past 20 years concerning the representations and practices ofelementary teachers regarding the relative importance given to subject matter and the use ofinterdisciplinarity in their teaching practice. The first section will explain the context of the Quebecschool system on a socio-historical and political level and review the emergence of the concept ofinterdisciplinarity in Quebec. The second section will present succinctly the different research projectsthat have been conducted since 1980 and the conceptual framework they were based on. The thirdsection will consider the main results of the various research projects from two angles: first, therepresentations and practices of the teachers regarding interdisciplinarity; secondly, the relativeimportance and role that the teachers give to interdisciplinarity. In the conclusion, we will highlightamong other things the central position teachers give to the role of socialization and their minimalconsideration for the teaching of disciplinary knowledge.

  10. Online citizen panels as an advance in research and consultation – A Review of pilot results

    Directory of Open Access Journals (Sweden)

    Anne Sharp

    2010-07-01

    Full Text Available This paper details a new model for local government consultation and research. The model involves a local government partnering with a university to establish an online panel of citizens that is then used for consultations and research on a range of local government issues over time. The model was evaluated across an 18-month pilot involving three metropolitan councils in South Australia, each running its own panel. This paper details the rationale behind the panels, steps involved in their establishment, and what the most effective recruitment methods were to build panel membership. The model’s ability to recruit a wide audience of citizens as members, including those who would not normally participate in local government matters, is examined, as well as citizen expectations of the panel and satisfaction with being a member. Finally, key learnings from the pilot are identified. The pilot results demonstrate that such an online panel model can be used effectively in the local government context. The panels achieved citizen membership wider than that historically seen in local government consultation and research, and were sustainable in terms of continued participation and high levels of citizen satisfaction. Since the pilot, the project has grown to include seven councils and almost 2500 citizens. This is further evidence that this model offers a way forward for enhanced citizen participation in local government decision-making and policy development.

  11. NASA Enterprise Architecture and Its Use in Transition of Research Results to Operations

    Science.gov (United States)

    Frisbie, T. E.; Hall, C. M.

    2006-12-01

    Enterprise architecture describes the design of the components of an enterprise, their relationships and how they support the objectives of that enterprise. NASA Stennis Space Center leads several projects involving enterprise architecture tools used to gather information on research assets within NASA's Earth Science Division. In the near future, enterprise architecture tools will link and display the relevant requirements, parameters, observatories, models, decision systems, and benefit/impact information relationships and map to the Federal Enterprise Architecture Reference Models. Components configured within the enterprise architecture serving the NASA Applied Sciences Program include the Earth Science Components Knowledge Base, the Systems Components database, and the Earth Science Architecture Tool. The Earth Science Components Knowledge Base systematically catalogues NASA missions, sensors, models, data products, model products, and network partners appropriate for consideration in NASA Earth Science applications projects. The Systems Components database is a centralized information warehouse of NASA's Earth Science research assets and a critical first link in the implementation of enterprise architecture. The Earth Science Architecture Tool is used to analyze potential NASA candidate systems that may be beneficial to decision-making capabilities of other Federal agencies. Use of the current configuration of NASA enterprise architecture (the Earth Science Components Knowledge Base, the Systems Components database, and the Earth Science Architecture Tool) has far exceeded its original intent and has tremendous potential for the transition of research results to operational entities.

  12. The psychological behaviorism theory of pain and the placebo: its principles and results of research application.

    Science.gov (United States)

    Staats, Peter S; Hekmat, Hamid; Staats, Arthur W

    2004-01-01

    The psychological behaviorism theory of pain unifies biological, behavioral, and cognitive-behavioral theories of pain and facilitates development of a common vocabulary for pain research across disciplines. Pain investigation proceeds in seven interacting realms: basic biology, conditioned learning, language cognition, personality differences, pain behavior, the social environment, and emotions. Because pain is an emotional response, examining the bidirectional impact of emotion is pivotal to understanding pain. Emotion influences each of the other areas of interest and causes the impact of each factor to amplify or diminish in an additive fashion. Research based on this theory of pain has revealed the ameliorating impact on pain of (1) improving mood by engaging in pleasant sexual fantasies, (2) reducing anxiety, and (3) reducing anger through various techniques. Application of the theory to therapy improved the results of treatment of osteoarthritic pain. The psychological behaviorism theory of the placebo considers the placebo a stimulus conditioned to elicit a positive emotional response. This response is most powerful if it is elicited by conditioned language. Research based on this theory of the placebo that pain is ameliorated by a placebo suggestion and augmented by a nocebo suggestion and that pain sensitivity and pain anxiety increase susceptibility to a placebo.

  13. Identifying creative research accomplishments: Methodology and results for nanotechnology and human genetics

    NARCIS (Netherlands)

    Heinze, Thomas; Shapira, Philip; Senker, Jacqueline; Kuhlmann, Stefan

    2007-01-01

    Motivated by concerns about the organizational and institutional conditions that foster research creativity in science, we focus on how creative research can be defined, operationalized, and empirically identified. A functional typology of research creativity is proposed encompassing theoretical, me

  14. Analysis of the antioxidant capacities of flavonoids under different spectrophotometric assays using cyclic voltammetry and density functional theory.

    Science.gov (United States)

    Zhang, Di; Chu, Le; Liu, Yixiang; Wang, Aili; Ji, Baoping; Wu, Wei; Zhou, Feng; Wei, Ying; Cheng, Qian; Cai, Shengbao; Xie, Liyang; Jia, Gang

    2011-09-28

    Flavonoids often show inconsistent antioxidant activities (AAs) depending on the assay used. The electrochemical properties of 14 flavonoid standards in cyclic voltammetry [area under anodic wave (Q) and oxidant peak potentials (Epa)] and the structural parameters [bond dissociation enthalpy (BDE) and ionization potential (IP)] were investigated. They were compared with the results of four spectrophotometric assays, namely, diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu reagent (FCR), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), to analyze the chemical reasons for the varying AAs of flavonoids under different assays. Using the cyclic voltammetry method, the AAs of the flavonoids in the DPPH, FCR, and FRAP assays were mainly determined by the ease of charge transferring in the first oxidation step. Meanwhile, the results of TEAC assays were primarily influenced by the amount of charge transfer in the multiple oxidation steps (MOS) of flavonoids. In the theoretical calculation, the BDE values of the selected flavonoids had considerably higher correlations with the results of the DPPH assay (r2=0.89) compared with the other three assays, which indicates that the oxidant-scavenging reaction of the tested flavonoids in the DPPH assay is closer to a hydrogen atom transfer mechanism. Neither the IP values nor BDE values had satisfactory correlation with the AAs of the flavonoids in the TEAC assay (r2=0.57, r2=0.54, respectively), Therefore, complex reaction mechanisms underlie this method and appropriate structural descriptors for reflecting the AAs of flavonoids based on MOS (e.g., TEAC values) need further investigation.

  15. Cyclic Voltammetry Measurement for Cu2O Based Homostructure Thin Film

    Science.gov (United States)

    Mohamad Arifin, Nurliyana Binti; Mohamad, Fariza Binti; Sikh Anuar, Nur Fathiah Binti; Ahmad, Nabihah Binti; Nor, Nik Hisyamudin Muhd; Izaki, Masanobu

    2017-08-01

    This experiment is about fabrication of homojunction Copper Oxide (Cu2O) thin film by using electrodeposition method. The p-n homojunction Cu2O was successfully prepared by consecutively depositing p-type Cu2O layer on n-type Cu2O layer by using copper acetate based solution through potentiostatic electrodeposition. At first, the n-type Cu2O was fabricated at pH 6.2 and 6.5 with fixed potential of -0.125V vs Ag/AgCl and time deposition at 30 minutes. Cyclic voltammetry (CV) measurement was carried out on this sample to determine the ideal potential range for fabrication of p-type Cu2O on n-type Cu2O/FTO substrate. From the result, deposition potential of -0.35V and -0.4V vs Ag/AgCl were appropriated for p-type Cu2O thin film fabrication. These potential values were variable with the selected pH values of 12.0 and 12.5 to fabricate the p-type Cu2O thin film. The other parameters such as deposition time fixed at 2 hours bath temperature was set up at 60°C. It was found that the optimum potential deposition was -0.4V vs Ag/AgCl and pH value appropriate for homostructure Cu2O thin film was pH 12.5. Morphological, structural, optical and conductivity characterization of p-n homojunction Cu2O thin film was characterized using Field Emission Scanning Electron Microscopy, X-Ray Diffractometer, Ultraviolet-Visible Spectroscopy and Photoelectrochemical (PEC) cells, respectively.

  16. Attributes of researchers and their strategies to recruit minority populations: results of a national survey.

    Science.gov (United States)

    Quinn, Sandra Crouse; Butler, James; Fryer, Craig S; Garza, Mary A; Kim, Kevin H; Ryan, Christopher; Thomas, Stephen B

    2012-11-01

    Despite NIH mandates for inclusion, recruiting minorities is challenging for biomedical and public health researchers. Little is known about how attributes of researchers affect their choice of recruitment strategies. The purpose of this study was to address this gap by examining how use of recruitment strategies relates to other researcher characteristics. To do this, we conducted an online survey from May to August 2010 with researchers (principal investigators, research staff, and IRB members) in which we measured the number and types of recruitment strategies utilized, along with other characteristics of the researchers and their research. We identified two clusters of researchers: comprehensive researchers who utilized a greater number and more diverse and active recruitment strategies, and traditional researchers, who utilized fewer and more passive strategies. Additional characteristics that distinguished the two groups were that comprehensive researchers were more likely than traditional researchers to 1) report racial and ethnic differences as one of their specific aims or hypotheses, 2) receive federal (CDC and NIH) funding, 3) conduct behavioral or epidemiological research, and 4) have received training in conducting research with and recruiting minorities. Traditional researchers, on the other hand, were more likely to conduct clinical research and a greater (though non-significant) percentage received funding from pharmaceutical sources. This study provides a novel description of how researcher attributes are related to their recruitment strategies and raises a number of future research questions to further examine the implications of this relationship.

  17. Can Research Design Explain Variation in Head Start Research Results? A Meta-Analysis of Cognitive and Achievement Outcomes

    Science.gov (United States)

    Shager, Hilary M.; Schindler, Holly S.; Magnuson, Katherine A.; Duncan, Greg J.; Yoshikawa, Hirokazu; Hart, Cassandra M. D.

    2013-01-01

    This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and…

  18. Can Research Design Explain Variation in Head Start Research Results? A Meta-Analysis of Cognitive and Achievement Outcomes

    Science.gov (United States)

    Shager, Hilary M.; Schindler, Holly S.; Magnuson, Katherine A.; Duncan, Greg J.; Yoshikawa, Hirokazu; Hart, Cassandra M. D.

    2013-01-01

    This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and…

  19. Electron reduction processes of nitrothiophenes. A systematic approach by DFT computations, cyclic voltammetry and E-ESR spectroscopy.

    Science.gov (United States)

    Boga, Carla; Calvaresi, Matteo; Franchi, Paola; Lucarini, Marco; Fazzini, Silvia; Spinelli, Domenico; Tonelli, Domenica

    2012-10-21

    In the framework of the interest in nitrothiophenes as drugs or hits with different pharmacological applications and considering that in several instances nitroreduction is an essential step for their biological activity, we have studied a complete series of mono-, di-, and tri-nitrothiophenes (1-6) and by comparison some mononitro benzo[b]thiophenes and benzo[b]furans (7-10). Their electroreduction behaviour has been investigated by different techniques: DFT calculations, cyclic voltammetry and electrochemical electron spin resonance spectroscopy. Although, the first reduction process for all of the compounds leads to the relevant radical anions, both the computational and experimental results indicate that there are significant differences in the fate of their corresponding forthcoming reductions, for example, formation of secondary radicals (open-shell electronic structures) or dianions. The effect of the relative positions of the nitro groups during the reduction has also been analysed and rationalised.

  20. Binding and conformational changes of human serum albumin upon interaction with 4-aminoantipyrine studied by spectroscopic methods and cyclic voltammetry.

    Science.gov (United States)

    Gowda, Jayant I; Nandibewoor, Sharanappa T

    2014-04-24

    The interactions of 4-aminoantipyrine (AAP) with human serum albumin (HSA) have been studied by UV-visible spectroscopy, fluorescence spectroscopy and cyclic voltammetry. The binding of 4-aminoantipyrine quenches the HSA fluorescence, revealing a 1:1 interaction with a binding constant of about 10(5) M(-1). The experimental results showed that AAP effectively quenched the intrinsic fluorescence of HSA via dynamic type of quenching. In addition, according to the synchronous fluorescence spectra of HSA in presence of 4-aminoantipyrine, the tryptophan residue of the proteins are most perturbed by the binding process. The number of binding sites, the binding constant, site probe study, some common metal ions effect and the thermodynamic parameters were calculated.

  1. Microdetermination of human serum albumin by differential pulse voltammetry at a L-cysteine modified silver electrode

    Indian Academy of Sciences (India)

    Liyuan Lu; Yanqin Zi; Hongling Wang

    2008-07-01

    A simple and highly sensitive electrochemical method for the determination of human serum albumin (HSA) using differential pulse voltammetry (DPV), based on a silver electrode modified with a self-assembled monolayer of L-cysteine, was developed. L-cysteine can be modified onto a silver electrode by covalent bonding through the sulfur to give stable and long-lived chemical electrodes. This electrode showed good sensitivity, selectivity, reproducibility and time stability in the determination of trace amounts of HSA by DPV technique. The detection limit can be as low as 4 × 10-17 mol/L. The optimum conditions for the determination were carefully investigated. This method had been applied to the determination of HSA in human serum samples. The results were in agreement with those given in standard method.

  2. Study on Water—Soluble Organic Reducing Substances.I.Determination of Organic Reducing Substances by Differential Pulse Voltammetry

    Institute of Scientific and Technical Information of China (English)

    WUYOU-XIAN; DINGCHANG-PU

    1991-01-01

    A new method was proposed for study of organic reducing substances in soils.According to the theoretical relationship between the voltammetric behaviors and reduction-oxidation reaction of reducing substances,the working conditions of differential pulse voltammetry (d.p.v.)for determining the organic reducing substances produced during the processes of the anaerobic decomposition of plant materials were established with a glass carbon electrode as working electrode,1M Ag-AgCl electrode with large area as reference electrode,0.2M NH4Ac as supporting from -0.5 to +1.2 voltage(vs.M Ag-AgCl).The peak current proportional to the concentration of reducing substances,and the characteristic peak potential of each organic reducing substance were regarded as the quantitative and qualitative base,respectively.These results obtained under the conditions mentioned above directly reflect both the reducing intensity and capacity of the organic reducing system in soils.

  3. Extending the dynamic range of copper determination in differential pulse adsorption cathodic stripping voltammetry using wavelet neural network.

    Science.gov (United States)

    Khayamian, T; Ensafi, Ali A; Benvidi, A

    2006-07-15

    A wavelet neural network (WNN) model is proposed for extending the dynamic range of Cu(II) determination by differential pulse adsorption cathodic stripping voltammetry (DP-AdSV) using xylenol orange (XO) as a suitable ligand. All of voltammograms data consisting of Cu(II) and Cu(II)-XO peak currents were used in WNN model. The WNN model consisted of three layers (2-8-1) with the Morlet mother wavelet transfer function in the hidden layer. The model was able to extend the dynamic range of Cu(II) from its narrow linear range (1-50 ng ml(-1)) to the higher dynamic range (1-1500 ng ml(-1)). The results of the WNN model was also compared with artificial neural network (ANN) model and it was demonstrated the superiority of the WNN model relative to ANN model.

  4. Determination of trace amounts of Ga(III) by adsorptive stripping voltammetry with in situ plated bismuth film electrode.

    Science.gov (United States)

    Grabarczyk, Malgorzata; Wasąg, Joanna

    2015-11-01

    The determination of trace gallium using adsorptive stripping voltammetry at an in situ plated bismuth film electrode was described. The method was based on simultaneous film formation and the Ga(III)-cupferron complex preconcentration at -0.65 V and its cathodic stripping during the potential scan. The effect of Bi(III) and cupferron concentration, the influence of deposition potential and time, and the scan rate on the determination of Ga(III) were studied. A linear response in the concentration range of 3×10(-10) to 3×10(-7) mol L(-1) (r=0.998) was obtained with detection limit of 1.05×10(-10) mol L(-1) using accumulation time of 180 s. Finally, the bismuth film electrode was successfully applied for the determination of Ga(III) in certified reference material seawater NASS-5 with satisfactory results.

  5. Investigation of the reduction process of dopamine using paired pulse voltammetry

    Science.gov (United States)

    Kim, Do Hyoung; Oh, Yoonbae; Shin, Hojin; Blaha, Charles D.; Bennet, Kevin E.; Lee, Kendall H.; Kim, In Young; Jang, Dong Pyo

    2014-01-01

    The oxidation of dopamine (DA) around +0.6V potential in anodic sweep and its reduction around −0.1V in cathodic sweep at a relatively fast scanning rate (300 V/s or greater) have been used for identification of DA oxidation in fast-scan cyclic voltammetry (FSCV). However, compared to the oxidation peak of DA, the reduction peak has not been fully examined in analytical studies, although it has been used as one of the representative features to identify DA. In this study, the reduction process of DA was investigated using paired pulse voltammetry (PPV), which consists of two identical triangle-shaped waveforms, separated by a short interval at the holding potential. Especially, the discrepancies between the magnitude of the oxidation and reduction peaks of DA were investigated based on three factors: (1) the instant desorption of the DA oxidation product (dopamine-o-quinone: DOQ) after production, (2) the effect of the holding potential on the reduction process, and (3) the rate-limited reduction process of DA. For the first test, the triangle waveform FSCV experiment was performed on DA with various scanrates (from 400 to 1000 V/s) and durations of switching potentials of the triangle waveform (from 0.0 to 6.0 ms) in order to vary the duration between the applied oxidation potential at +0.6V and the reduction potential at −0.2V. As a result, the ratio of reduction over oxidation peak current response decreased as the duration became longer. To evaluate the effect of holding potentials during the reduction process, FSCV experiments were conducted with holding potential from 0.0V to −0.8V. We found that more negative holding potentials lead to larger amount of reduction process. For evaluation of the rate-limited reduction process of DA, PPV with a 1Hz repetition rate and various delays (2, 8, 20, 40 and 80ms) between the paired scans were utilized to determine how much reduction process occurred during the holding potential (−0.4V). These tests showed that

  6. Investigation of the reduction process of dopamine using paired pulse voltammetry.

    Science.gov (United States)

    Kim, Do Hyoung; Oh, Yoonbae; Shin, Hojin; Blaha, Charles D; Bennet, Kevin E; Lee, Kendall H; Kim, In Young; Jang, Dong Pyo

    2014-03-15

    The oxidation of dopamine (DA) around +0.6V potential in anodic sweep and its reduction around -0.1V in cathodic sweep at a relatively fast scanning rate (300 V/s or greater) have been used for identification of DA oxidation in fast-scan cyclic voltammetry (FSCV). However, compared to the oxidation peak of DA, the reduction peak has not been fully examined in analytical studies, although it has been used as one of the representative features to identify DA. In this study, the reduction process of DA was investigated using paired pulse voltammetry (PPV), which consists of two identical triangle-shaped waveforms, separated by a short interval at the holding potential. Especially, the discrepancies between the magnitude of the oxidation and reduction peaks of DA were investigated based on three factors: (1) the instant desorption of the DA oxidation product (dopamine-o-quinone: DOQ) after production, (2) the effect of the holding potential on the reduction process, and (3) the rate-limited reduction process of DA. For the first test, the triangle waveform FSCV experiment was performed on DA with various scanrates (from 400 to 1000 V/s) and durations of switching potentials of the triangle waveform (from 0.0 to 6.0 ms) in order to vary the duration between the applied oxidation potential at +0.6V and the reduction potential at -0.2V. As a result, the ratio of reduction over oxidation peak current response decreased as the duration became longer. To evaluate the effect of holding potentials during the reduction process, FSCV experiments were conducted with holding potential from 0.0V to -0.8V. We found that more negative holding potentials lead to larger amount of reduction process. For evaluation of the rate-limited reduction process of DA, PPV with a 1Hz repetition rate and various delays (2, 8, 20, 40 and 80ms) between the paired scans were utilized to determine how much reduction process occurred during the holding potential (-0.4V). These tests showed that

  7. Current research and future directions in pattern identification: Results of an international symposium.

    Science.gov (United States)

    Lee, Myeong Soo; Lee, Ju Ah; Alraek, Terje; Bian, Zhao-Xiang; Birch, Stephen; Goto, Hirozo; Jung, Jeeyoun; Kao, Shung-Te; Moon, Sang-Kwan; Park, Bongki; Park, Kyung-Mo; You, Sooseong; Yun, Kyung-Jin; Zaslawski, Chris

    2016-12-01

    A symposium on pattern identification (PI) was held at the Korea Institute of Oriental Medicine (KIOM) on October 2, 2013, in Daejeon, South Korea. This symposium was convened to provide information on the current research in PI as well as suggest future research directions. The participants discussed the nature of PI, possible research questions, strategies and future international collaborations in pattern research. With eight presentations and an extensive panel discussion, the symposium allowed participants to discuss research methods in traditional medicine for PI. One speaker presented the topic, 'Clinical pattern differentiation and contemporary research in PI.' Two speakers presented current trends in research on blood stasis while the remaining five other delegates discussed the research methods and future directions of PI research. The participants engaged in in-depth discussions regarding the nature of PI, potential research questions, strategies and future international collaborations in pattern research.

  8. Comparison of results of experimental research with numerical calculations of a model one-sided seal

    Directory of Open Access Journals (Sweden)

    Joachimiak Damian

    2015-06-01

    Full Text Available Paper presents the results of experimental and numerical research of a model segment of a labyrinth seal for a different wear level. The analysis covers the extent of leakage and distribution of static pressure in the seal chambers and the planes upstream and downstream of the segment. The measurement data have been compared with the results of numerical calculations obtained using commercial software. Based on the flow conditions occurring in the area subjected to calculations, the size of the mesh defined by parameter y+ has been analyzed and the selection of the turbulence model has been described. The numerical calculations were based on the measurable thermodynamic parameters in the seal segments of steam turbines. The work contains a comparison of the mass flow and distribution of static pressure in the seal chambers obtained during the measurement and calculated numerically in a model segment of the seal of different level of wear.

  9. First results from the LUX dark matter experiment at the Sanford Underground Research Facility

    CERN Document Server

    Akerib, D S; Bai, X; Bailey, A J; Balajthy, J; Bedikian, S; Bernard, E; Bernstein, A; Bolozdynya, A; Bradley, A; Byram, D; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chapman, J J; Chiller, A A; Chiller, C; Clark, K; Coffey, T; Currie, A; Curioni, A; Dazeley, S; de Viveiros, L; Dobi, A; Dobson, J; Dragowsky, E M; Druszkiewicz, E; Edwards, B; Faham, C H; Fiorucci, S; Flores, C; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C; Hanhardt, M; Hertel, S A; Horn, M; Huang, D Q; Ihm, M; Jacobsen, R G; Kastens, L; Kazkaz, K; Knoche, R; Kyre, S; Lander, R; Larsen, N A; Lee, C; Leonard, D S; Lesko, K T; Lindote, A; Lopes, M I; Lyashenko, A; Malling, D C; Mannino, R; McKinsey, D N; Mei, D -M; Mock, J; Moongweluwan, M; Morad, J; Morii, M; Murphy, A St J; Nehrkorn, C; Nelson, H; Neves, F; Nikkel, J A; Ott, R A; Pangilinan, M; Parker, P D; Pease, E K; Pech, K; Phelps, P; Reichhart, L; Shutt, T; Silva, C; Skulski, W; Sofka, C J; Solovov, V N; Sorensen, P; Stiegler, T; O`Sullivan, K; Sumner, T J; Svoboda, R; Sweany, M; Szydagis, M; Taylor, D; Tennyson, B; Tiedt, D R; Tripathi, M; Uvarov, S; Verbus, J R; Walsh, N; Webb, R; White, J T; White, D; Witherell, M S; Wlasenko, M; Wolfs, F L H; Woods, M; Zhang, C

    2013-01-01

    The Large Underground Xenon (LUX) experiment, a dual-phase xenon time-projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota), was cooled and filled in February 2013. We report results of the first WIMP search dataset, taken during the period April to August 2013, presenting the analysis of 85.3 live-days of data with a fiducial volume of 118 kg. A profile-likelihood analysis technique shows our data to be consistent with the background-only hypothesis, allowing 90% confidence limits to be set on spin-independent WIMP-nucleon elastic scattering with a minimum upper limit on the cross section of $7.6 \\times 10^{-46}$ cm$^{2}$ at a WIMP mass of 33 GeV/c$^2$. We find that the LUX data are in strong disagreement with low-mass WIMP signal interpretations of the results from several recent direct detection experiments.

  10. Botswana water and surface energy balance research program. Part 1: Integrated approach and field campaign results

    Science.gov (United States)

    Vandegriend, A. A.; Owe, M.; Vugts, H. F.; Ramothwa, G. K.

    1992-01-01

    The Botswana water and surface energy balance research program was developed to study and evaluate the integrated use of multispectral satellite remote sensing for monitoring the hydrological status of the Earth's surface. Results of the first part of the program (Botswana 1) which ran from 1 Jan. 1988 - 31 Dec. 1990 are summarized. Botswana 1 consisted of two major, mutually related components: a surface energy balance modeling component, built around an extensive field campaign; and a passive microwave research component which consisted of a retrospective study of large scale moisture conditions and Nimbus scanning multichannel microwave radiometer microwave signatures. The integrated approach of both components in general are described and activities performed during the surface energy modeling component including the extensive field campaign are summarized. The results of the passive microwave component are summarized. The key of the field campaign was a multilevel approach, whereby measurements by various similar sensors were made at several altitudes and resolution. Data collection was performed at two adjacent sites of contrasting surface character. The following measurements were made: micrometeorological measurements, surface temperatures, soil temperatures, soil moisture, vegetation (leaf area index and biomass), satellite data, aircraft data, atmospheric soundings, stomatal resistance, and surface emissivity.

  11. Nodalization effects on RELAP5 results related to MTR research reactor transient scenarios

    Directory of Open Access Journals (Sweden)

    Khedr Ahmed

    2005-01-01

    Full Text Available The present work deals with the anal y sis of RELAP5 results obtained from the evaluation study of the total loss of flow transient with the deficiency of the heat removal system in a research reactor using two different nodalizations. It focuses on the effect of nodalization on the thermal-hydraulic evaluation of the re search reactor. The analysis of RELAP5 results has shown that nodalization has a big effect on the predicted scenario of the postulated transient. There fore, great care should be taken during the nodalization of the reactor, especially when the avail able experimental or measured data are insufficient for making a complete qualification of the nodalization. Our analysis also shows that the research reactor pool simulation has a great effect on the evaluation of natural circulation flow and on other thermal-hydraulic parameters during the loss of flow transient. For example, the on set time of core boiling changes from less than 2000 s to 15000 s, starting from the beginning of the transient. This occurs if the pool is simulated by two vertical volumes in stead of one vertical volume.

  12. Recent Research Results in the Field of Electric Drives and Mechatronics

    Directory of Open Access Journals (Sweden)

    Rastislav Tabacek

    2003-01-01

    Full Text Available The paper presents an overview of research results achieved in the field of Electrical Drives and Mechatronics for the period of three years. The achieved outputs are formed into three individual parts. In the field of Electric Drives the most significant outputs have been achieved in the development of a new control algorithms for a.c. drives under general name 'Forced Dynamics Control' , in improvement of shaft sensorless control methods and in implementation of developed algorithms via digital signal processors. In the field of Electric Traction the most important results have been gained in optimization of power of traction vehicles andat development of diagnostic systems for evaluation of technical conditions of traction devices. In the field of Electric Machines the most important outputs have been achieved in the research of modern electronically commutated electrical machines, their performances in steady and transient states, new design method for their configuration and new methods for automatic parameters identification. In the end the list of the most important publications for all three parts is enclosed.

  13. NASA Glenn Icing Research Tunnel: 2014 and 2015 Cloud Calibration Procedures and Results

    Science.gov (United States)

    Steen, Laura E.; Ide, Robert F.; Van Zante, Judith F.; Acosta, Waldo J.

    2015-01-01

    This report summarizes the current status of the NASA Glenn Research Center (GRC) Icing Research Tunnel cloud calibration: specifically, the cloud uniformity, liquid water content, and drop-size calibration results from both the January-February 2014 full cloud calibration and the January 2015 interim cloud calibration. Some aspects of the cloud have remained the same as what was reported for the 2014 full calibration, including the cloud uniformity from the Standard nozzles, the drop-size equations for Standard and Mod1 nozzles, and the liquid water content for large-drop conditions. Overall, the tests performed in January 2015 showed good repeatability to 2014, but there is new information to report as well. There have been minor updates to the Mod1 cloud uniformity on the north side of the test section. Also, successful testing with the OAP-230Y has allowed the IRT to re-expand its operating envelopes for large-drop conditions to a maximum median volumetric diameter of 270 microns. Lastly, improvements to the collection-efficiency correction for the SEA multi-wire have resulted in new calibration equations for Standard- and Mod1-nozzle liquid water content.

  14. Preliminary Results From NASA's Space Solar Power Exploratory Research and Technology Program

    Science.gov (United States)

    Howell, Joe T.; Mankins, John C.

    2000-01-01

    Large solar power satellite (SPS) systems that might provide base load power into terrestrial markets were examined extensively in the 1970s by the US Department of Energy (DOE) and the National Aeronautics and Space Administration (NASA). Following a hiatus of about 15 years, the subject of space solar power (SSP) was reexamined by NASA from 1995-1997 in the "fresh look" study, and during 1998 in an SSP "concept definition study". As a result of these efforts, during 1999-2000, NASA has been conducting the SSP Exploratory Research and Technology (SERT) program. The goal of the SERT activity has been to conduct preliminary strategic technology research and development to enable large, multi-megawatt SSP systems and wireless power transmission (WPT) for government missions and commercial markets (in-space and terrestrial). In pursuing that goal, the SERT: (1) refined and modeled systems approaches for the utilization of SSP concepts and technologies, ranging from the near-term (e.g., for space science, exploration and commercial space applications) to the far-term (e.g., SSP for terrestrial markets), including systems concepts, architectures, technology, infrastructure (e.g. transportation), and economics; (2) conducted technology research, development and demonstration activities to produce "proof-of-concept" validation of critical SSP elements for both nearer and farther-term applications; and (3) engendered the beginnings of partnerships (nationally and internationally) that could be expanded, as appropriate, to pursue later SSP technology and applications. Through these efforts, the SERT should allow better informed future decisions regarding further SSP and related technology research and development investments by both NASA and prospective partners, and guide further definition of technology roadmaps - including performance objectives, resources and schedules, as well as "multi-purpose" applications (e.g., commerce, science, and government). This paper

  15. Direct electrodeposition of gold nanotube arrays of rough and porous wall by cyclic voltammetry and its applications of simultaneous determination of ascorbic acid and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    Yang Guangming, E-mail: yangguangmingbs@126.com [Department of Resources and Environment, Baoshan University, Baoshan 678000 (China); Li Ling [Department of Resources and Environment, Baoshan University, Baoshan 678000 (China); Jiang Jinhe; Yang Yunhui [College of Chemistry and Chemical Engineering, Yunnan Normal University, Kunming 650092 (China)

    2012-08-01

    Gold nanotube arrays of rough and porous wall has been synthesized by direct electrodeposition with cyclic voltammetry utilizing anodic aluminum oxide template (AAO) and polycarbonate membrane (PC) during short time (only 3 min and 2 min, respectively). The mechanism of the direct electrodeposition of gold nanotube arrays by cyclic voltammetry (CV) has been discussed. The morphological characterizations of the gold nanotube arrays have been investigated by scanning electron microscopy (SEM). A simultaneous determination of ascorbic acid (AA) and uric acid (UA) by differential pulse voltammetry (DPV) was constructed by attaching gold nanotube arrays (using AAO) onto the surface of a glassy carbon electrode (GCE). The electrochemical behavior of AA and UA at this modified electrode has been studied by CV and differential pulse voltammetry (DPV). The sensor offers an excellent response for AA and UA and the linear response range for AA and UA were 1.02 Multiplication-Sign 10{sup -7}-5.23 Multiplication-Sign 10{sup -4} mol L{sup -1} and 1.43 Multiplication-Sign 10{sup -7}-4.64 Multiplication-Sign 10{sup -4} mol L{sup -1}, the detection limits were 1.12 Multiplication-Sign 10{sup -8} mol L{sup -1} and 2.24 Multiplication-Sign 10{sup -8} mol L{sup -1}, respectively. This sensor shows good regeneration, stability and selectivity and has been used for the determination of AA and UA in real human urine and serum samples with satisfied results. - Graphical abstract: The schematic diagram of formation of Au nanotube arrays (a) and the stepwise procedure of the sensor (b). Highlights: Black-Right-Pointing-Pointer Gold nanotubes array has been synthesized by cyclic voltammetry. Black-Right-Pointing-Pointer The mechanism of deposition of gold nanotube has been discussed. Black-Right-Pointing-Pointer A determination of ascorbic acid and uric acid was constructed by gold array. Black-Right-Pointing-Pointer A satisfied determination of samples can be obtained by this sensor.

  16. Determination of Ammonium Ion in Lake Water by Voltammetry

    Institute of Scientific and Technical Information of China (English)

    Wu Yun-hua; Fei Jun-jie; Dang Xue-ping; Hu Sheng-shui

    2004-01-01

    An electroanalytical method for the determination of armonium ion using a platinized platinum electrode is described. Under optimized analytical conditions, the linear range of the calibration graphs for ammonium ion is 3. 0×10(-5)-5.0×10-3 mol·L-1.The Method has been applide to the determination of ammonium ion in lake water samples and recoveries of 100%-103%0 are obtained. The results obtained are found to be in good agreement with spectrophotometric results.

  17. Visual Literacy and Science Education: Results of a Qualitative Research Project

    Directory of Open Access Journals (Sweden)

    Regula Fankhauser

    2008-10-01

    Full Text Available In the didactics of science the role of pictures—mainly photographs and diagrams—as learning media and their function in the acquisition of knowledge have been discussed. However, the specific problems understanding pictures have seldom been reflected systematically. The aim of the project described in this paper was to address this deficiency. In a first step I refer to theoretical concepts of understanding pictures that were generated within the context of qualitative social research. Next I generate a theoretical model of visual literacy. The focus is on the understanding of pictures used in science education. The model includes aesthetic, epistemological, technical, and pragmatic dimensions. This model was then empirically tested. Thirty-five students were interviewed regarding their reception of scientific pictures. The results reveal that students have difficulties in describing the aesthetic features of pictures. The interviews clarified the epistemological frame theory on which picture understanding is based: most of the students consider the picture as a realistic copy of the object represented. Only a few students showed a more constructivist frame theory. Furthermore, the results revealed no connection between the epistemological theory and the technical knowledge of the students. The discussion of the design and the method of interpretation reflects the results of the study; the students' patterns of picture understanding are surprisingly homogeneous. On the one hand this could be reduced to the method of content analysis; on the other hand it could be an effect of the single sided view of the design. I explored only the subjective reception of pictures. Further research must consider other perspectives and focus on the way teachers work with visual material in classroom teaching. URN: urn:nbn:de:0114-fqs090129

  18. Acquisition and Cataloguing Processes: Changes as a Result of Customer Value Discovery Research

    Directory of Open Access Journals (Sweden)

    Sue McKnight

    2007-12-01

    Full Text Available Objective ‐ This study seeks to highlight the profound effect of Customer Value Discovery research on the internal business processes of two university libraries in the areas of cataloguing and acquisitions.Methods ‐ In this project, “Customer Discovery Workshops” with academic staff, students, and university stakeholders provided library managers and staff with information on what services and resources were of value to customers. The workshops also aimed to discover what features of existing library services and resources irritated the students, staff, and faculty. A student satisfaction survey assessed longer‐term impact of library changes to students in one university.Results ‐ The findings resulted in significant changes to collection development, acquisitions, and cataloguing processes. A number of value added services were introduced for the customer. The project also resulted in greater speed and efficiency in dealing with collection development, acquisitions, and cataloguing by the introduction of more technology‐enhanced services. Overall customer satisfaction was improved during the project period.Conclusion ‐ The changes to services introduced as a result of customer feedback also improved relationships between librarians and their university community, through the introduction of a more proactive and supportive service.

  19. The effects of climatic change on crop production. Results of a five-year research project

    Energy Technology Data Exchange (ETDEWEB)

    Mela, T.; Carter, T.; Hakala, K.; Kaukoranta, T.; Laurila, H.; Niemi, K.; Saarikko, R.; Tiilikkala, K. [Agricultural Research Centre of Finland, Jokioinen (Finland); Hannukkala, A. [Agricultural Research Centre, Rovaniemi (Finland). Lapland Research Station

    1996-12-31

    The aim of this research project, funded jointly by SILMU and by the Agricultural Research Centre of Finland, was to evaluate the possible effects of changes in climate and carbon dioxide concentration on the growth, development and yield of field crops and on crop pests and diseases in Finland. The study focused on two cereal crops (spring wheat and spring barley), a grass species (meadow fescue), some common pathogens of cereals and potato, insect pests of small fruits and nematode risk of potato and sugar beet. The results of this study indicate the following effects on crop production of the `best guess` climate change anticipated for Finland by 2050: A lengthening of the potential growing season of 3-5 weeks. A northward expansion of about 250-500 km in suitability for cereal production. Increased yields of adapted spring cereals. New, longer-season cultivars would benefit from both higher temperatures and elevated CO{sub 2}. Improved potential for the cultivation of higher-yielding winter sown cereals. Increased grass yields due to a lengthening growing season and increased growth rates, assuming that water and nutrient limitations are minor. However, there is a possibility of reduced winter hardening under higher autumn temperatures and an increased risk of winter damage. Potential for the successful cultivation of new crops like maize in southern Finland. Increased potential for yield losses due to crop pests and diseases under climatic warming. The range of many species is expected to expand northwards, additional generations of some species would develop successfully, and new species may become established in Finland. The research is continuing as part of a new European Community project, and will explore a wider range of crop types, focusing on the effects of climate change on agricultural risk at national scale

  20. Cultural adaptation and validation of an instrument on barriers for the use of research results.

    Science.gov (United States)

    Ferreira, Maria Beatriz Guimarães; Haas, Vanderlei José; Dantas, Rosana Aparecida Spadoti; Felix, Márcia Marques Dos Santos; Galvão, Cristina Maria

    2017-03-02

    to culturally adapt The Barriers to Research Utilization Scale and to analyze the metric validity and reliability properties of its Brazilian Portuguese version. methodological research conducted by means of the cultural adaptation process (translation and back-translation), face and content validity, construct validity (dimensionality and known groups) and reliability analysis (internal consistency and test-retest). The sample consisted of 335 nurses, of whom 43 participated in the retest phase. the validity of the adapted version of the instrument was confirmed. The scale investigates the barriers for the use of the research results in clinical practice. Confirmatory factorial analysis demonstrated that the Brazilian Portuguese version of the instrument is adequately adjusted to the dimensional structure the scale authors originally proposed. Statistically significant differences were observed among the nurses holding a Master's or Doctoral degree, with characteristics favorable to Evidence-Based Practice, and working at an institution with an organizational cultural that targets this approach. The reliability showed a strong correlation (r ranging between 0.77 and 0.84, pcultura organizacional dirigida hacia tal aproximación. La fiabilidad presentó correlación fuerte (r variando entre 0,77 y 0,84, pcultura organizacional direcionada para tal abordagem. A confiabilidade apresentou correlação forte (r variando entre 0,77e 0,84, p<0,001) e a consistência interna foi adequada (alfa de Cronbach variando entre 0,77 e 0,82) . a versão para o português brasileiro do instrumento The Barriers Scale demonstrou-se válida e confiável no grupo estudado.

  1. Taking a Multi-pronged Approach to Expand the Reach of Climate Research Results

    Science.gov (United States)

    Hauser, R.; Unger, M.; Eastburn, T.; Rockwell, A.; Laursen, K. K.; National CenterAtmospheric Research

    2011-12-01

    Recognizing the importance of tailoring content to a variety of audiences, the National Center for Atmospheric Research (NCAR) takes a multi-pronged approach to expand the reach of climate research results. The center's communications and education and outreach teams leverage Web 1.0 and 2.0 functionality - Google searches, Twitter, Facebook, YouTube - as well as face-to-face interactions and traditional media outlets to ensure climate change messages effectively connect with multiple audiences. Key to these efforts, NCAR seeks to frame messages that emphasize cultural cognition, that is, in a manner that recognizes and resonates with different audiences' values and thus their identities. Among the basic communications approaches NCAR uses to engage the public are one-on-one interactions with the visiting public, which ranges from school children and tourists, to dignitaries and journalists. As an example, the NCAR Journalism Fellowship brings a competitively selected group of internatoinal journalists to NCAR. During a week-long visit and ongoing contact, journalists are provided with a close-up, nuanced view of the science and individuals working on the bigger-picture research that drives climate-related sound bites reported by the press. NCAR provides media training for its scientists, giving them tools and practice in effectively handling interviews for print, Web and radio outlets. The institution hosts public events like "Super Science Saturday," and NCAR staff participate in external activities such as school science fairs, community events and continuing education sessions. In addition to interactive displays that allow the public to "experience" science directly and informally, NCAR develops educational programs and curricula targeted to specific age groups and levels of expertise. We will explore the importance of analogies, images and anecdotes in explaining complicated subjects to such a varied set of audiences, and identify key concepts in simplifying

  2. Predicting research use in a public health policy environment: results of a logistic regression analysis.

    Science.gov (United States)

    Zardo, Pauline; Collie, Alex

    2014-10-09

    Use of research evidence in public health policy decision-making is affected by a range of contextual factors operating at the individual, organisational and external levels. Context-specific research is needed to target and tailor research translation intervention design and implementation to ensure that factors affecting research in a specific context are addressed. Whilst such research is increasing, there remain relatively few studies that have quantitatively assessed the factors that predict research use in specific public health policy environments. A quantitative survey was designed and implemented within two public health policy agencies in the Australian state of Victoria. Binary logistic regression analyses were conducted on survey data provided by 372 participants. Univariate logistic regression analyses of 49 factors revealed 26 factors that significantly predicted research use independently. The 26 factors were then tested in a single model and five factors emerged as significant predictors of research over and above all other factors. The five key factors that significantly predicted research use were the following: relevance of research to day-to-day decision-making, skills for research use, internal prompts for use of research, intention to use research within the next 12 months and the agency for which the individual worked. These findings suggest that individual- and organisational-level factors are the critical factors to target in the design of interventions aiming to increase research use in this context. In particular, relevance of research and skills for research use would be necessary to target. The likelihood for research use increased 11- and 4-fold for those who rated highly on these factors. This study builds on previous research and contributes to the currently limited number of quantitative studies that examine use of research evidence in a large sample of public health policy and program decision-makers within a specific context. The

  3. Results of research in the area of nanotechnologies and nanomaterials. Part 6

    Directory of Open Access Journals (Sweden)

    KARPOV Alexey Ivanovich

    2014-12-01

    Full Text Available To popularize scientific achievements in construction the main results of Russian and foreign scientists’ research are published in the form of abstract. The result of research «Cement composites with additives of multi-layer carbon nanotubes (MLCN» is a new production technology and optimal compositions for complex nanomodified additives (CNMA. Introduction of such additives in the quantity of 12 mass.% of cement mass provides within 8–12 hours early stripping strength more than 15–40 Mpa, water impermeability more than W20 and frost resistance F60–F700. The technology provides double increase of work performance and metalriging turnover. The difference between the new production technology and the traditional one is that the line of production of chemical additives contains a new unit designed for manufacture of CNMA based on MLCN. The unit consists of precision feeder (the size of dose is 5 g., ultrasound dispersant with power 4 kW and frequency of operation 22 kHz and turbulent mixer with power 7,5 kW. The developed technology provides precise dose and even distribution of CNMA in mixture. The author developed technical conditions № 5745-111-02069622-2013 for manufacture of CNMA based on MLCN of different refinement purity and dispersiveness for high strength reinforced-concrete blocks used as finishing materials in subway tunnels. The specialists may be also interested in results of the research «Nanostructured perlite binder and foam concrete based on it» by Miroshnikov E.V., «Constructional steel fiber concretes modified with complex carbon micro- and nanosize additives» by Alatorceva U.V., «Physical and chemical study of nanocomposite template-assembled materials produced with the controlled sol-gel synthesis» by Krekoten' A.V., «Production and study of nanoparticles of polymer-colloid complexes based on polymers of chloride N,N-diallyl-N,N-dimethylammonio and dodecylsulfate sodium» by Babaeva M.S.,

  4. Astrobiology Results from ILEWG EuroMoonMars Analogue Field Research

    Science.gov (United States)

    Foing, Bernard H.

    We give an update on the astrobiology results from a series of field research campaigns (ILEWG EuroMoonMars) in the extreme environment of the Utah desert. These are relevant to prepare future lunar landers and polar sample return missions, interpret Moon-Mars data (eg SMART1, LRO, Mars Express, MRO, MER, MSL), study habitability and astrobiology in Moon-Mars environments, or to test human-robotic surface EVA or base operations. In the frame of ILEWG EuroMoonMars campaigns (2009 to 2013) we deployed at Mars Desert Research station near Hanksville Utah, a suite of instruments and techniques [0, 1, 2, 9-11] including sample collection, context imaging from re-mote to local and microscale, drilling, spectrometers and life sensors. We analyzed how geological and geo-chemical evolution affected local parameters (mineralogy, organics content, environment variations) and the habitability and signature of organics and biota. Results: Among the important findings are the diversity in the composition of soil samples even when collected in close proximity, the low abundances of detectable PAHs and amino acids and the presence of biota of all three domains of life with significant heterogeneity. An extraordinary variety of putative extremophiles was observed [3,4,9]. A dominant factor seems to be soil porosity and lower clay-sized particle content [6-8]. A protocol was developed for sterile sampling, contamination issues, and the diagnostics of biodiversity via PCR and DGGE analysis in soils and rocks samples [10, 11]. We compare the 2009 campaign results [0-9] to new measurements from 2010-2013 campaigns relevant to: comparison between remote sensing and in-situ measurements; the study of minerals; the detection of organics and signs of life. We acknowledge team members and supporting institutes: B.H. Foing (1, 2, 6), C. Stoker (3), P. Ehrenfreund (4, 5), I. Rammos (2), L. Rodrigues (2), A. Svendsen (2), D. Oltheten (2), I. Schlacht (2), K. Nebergall (6), M. Battler (6, 7), H

  5. a Review of Railway Noise Research and Results Since the 5th Iwrn in Voss (norway)

    Science.gov (United States)

    GAUTIER, P.-E.

    2000-03-01

    Since the 1995 International Workshop on Railway Noise in Voss, two major elements may be considered as influential to railway noise research:— there is a clear and strong demand, at the European level as well as nationally for reducing railway noise in terms of operational solutions, especially for freight traffic,— theoretical developments for modelling rolling noise (which is the major source of noise for conventional speed) reached a point where operational developments of low noise solutions could be successfully carried out with the Twins model.Accordingly, research focused on developing such low noise solutions for rolling noise, investigating subsidiary and still unanswered questions, and addressing outstanding problems related to aerodynamic noise. In parallel to these propagation and annoyance studies were the subject of continuing interests, either with practical results or detailed on-going studies. Finally, modelling interior noise either with modal approaches for lower frequencies, or with SEA for higher frequencies, have proved successful in the case of high speed. Emerging subjects involve a revival of groundborne vibration modelling, roughness generation studies and decision management systems to get the greatest benefit from various potential solutions.

  6. [Freiburg keratoconus registry : Example of application of smart data for clinical research and inititial results].

    Science.gov (United States)

    Lang, S J; Böhringer, D; Reinhard, T

    2016-06-01

    Keratoconus is a progressive corneal disease with thinning and scarring of the cornea. Diagnostic and treatment options are usually evaluated in large prospective or retrospective trials. Big data and smart data provide the possibility to analyze routine data for clinical research. In this article we report the generation of a monocentric keratoconus registry by means of computerized data analysis of routine data. This demonstrates the potential of clinical research by means of routine data. A "clinical data warehouse" was created from all available routine electronic data. At the time of first presentation, each eye was classified into one out of four categories: suspected, early disease, late disease and status postkeratoplasty. Through integration of multiple data sources the clinical course for each patient was documented in the registry. A total of 3681 eyes from 1841 patients were included. The median follow-up time was 0.54 years. Patient age was higher in the groups with more severe stages of keratoconus, the proportion of female patients was higher in the group of suspected keratoconus and patient age and male to female ratios showed statistically significant differences between the groups (p keratoconus registry. Only the grading of disease severity and the exclusion of false positive results were carried out manually. In our opinion establishing a structured clinical data warehouse has a huge potential for clinical and retrospective studies and proves the value of the Smart Data concept.

  7. Supercapacitive evaluation of carbon black/exfoliated graphite/MnO{sub 2} ternary nanocomposite electrode by continuous cyclic voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Naderi, Hamid Reza, E-mail: hrnaderi@ut.ac.ir [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Norouzi, Parviz, E-mail: norouzi@khayam.ut.ac.ir [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology & Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ganjali, Mohammad Reza, E-mail: ganjali@khayam.ut.ac.ir [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Biosensor Research Center, Endocrinology & Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2015-08-01

    A new ternary nanocomposite was prepared by using MnO{sub 2}, carbon black (CB), and exfoliated graphite (EG) through a sonochemical method. In this process, the MnO{sub 2} nanoparticles was anchored on the mixture of CB and EG to maximize the specific capacitances of these materials. Structure and morphology of the CB/EG/MnO{sub 2} nanocomposites were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties of the CB/EG/MnO{sub 2} nanocomposites with different content of MnO{sub 2} were studied by cyclic voltammetry (CV), fast Fourier transformation continuous cyclic voltammetry (FFTCCV) technique, galvanostatic charge–discharge, and electrochemical impedance spectroscopy (EIS). The best nanocomposite electrode displayed specific capacitance of 364 F g{sup −1} at the scan rate of 2 mV s{sup −1} in 0.5 M Na{sub 2}SO{sub 4} aqueous solution, which is higher than pure MnO{sub 2} (289 F g{sup −1}). The capacitance stability of the nanocomposite electrode was studied by FFTCCV at the scan rate of 500 mV s{sup −1}. The result shows that after recording 4000 CVs, the specific capacitance of the nanocomposite decline only 5%. Furthermore, the nanocomposite electrode showed higher energy density than MnO{sub 2} electrode. - Highlights: • MnO{sub 2}/exfoliated graphite/Carbon black nanocomposites were synthesized by ultrasonic vibration. • The best nanocomposite electrode exhibits specific capacitance of 364 F g{sup −1} in 2 mV s{sup −1}. • The stability of the nanocomposite electrode was study FFTCCV technique. • The capacitance decreases only 5.2% of initial capacitance after 4000 cycles.

  8. Determination of tryptophan and histidine by adsorptive cathodic stripping voltammetry using H-point standard addition method.

    Science.gov (United States)

    Ensafi, Ali A; Hajian, R

    2006-11-24

    A sequential method is proposed for the determination of tryptophane and histidine by adsorptive cathodic stripping voltammetry using standard addition and H-point standard addition method (HPSAM). The complexes of copper(II) with the amino acids were accumulated onto the surface of a hanging mercury drop electrode for 60s. Then the preconcentrated complexes were reduced by square wave voltammetry and the peak currents were measured. The effect of various parameters such as pH, concentration of copper, accumulation potential, accumulation time and scan rate on the sensitivity were studied by one-at-a time and artificial neural network. Under the optimized conditions, the peak currents at about +0.05 to -0.30 V is proportional to the concentration of tryptophan and histidine over the concentration ranges of 5-220 and 100-1200 nM, respectively. Optimization of the parameters by one-at-a time showed that at accumulation potential of 0.10 V (versus Ag/AgCl reference electrode) the peak current is proportional only to the concentration of tryptophan and histidine does not have any contribution to the current. The optimization results by artificial neural network showed that at accumulation potential of -0.06 V (versus Ag/AgCl) the peak current is proportional to the both concentrations of tryptophan and histidine. Therefore, the method of H-point standard addition has been used for resolving overlap voltamograms for determination of histidine in the present of tryptophane. The method was successfully applied to the determination of tryptophan and histidine in synthetic and real samples.

  9. Women Entrepreneurship in the Western Romania. Research Results and Policy Recommendations

    Directory of Open Access Journals (Sweden)

    Anca DODESCU

    2011-01-01

    Full Text Available Starting from the results of the empirical, quantitative, and qualitative research performed in the AntrES project, between 5.01.2009 - 4.01.2011, in the Western Romania, referring to the existence of obvious gender gaps regarding the start up of new businesses and the ownership of the businesses; the characteristics, the motivations, and the difficulties of the women entrepreneurs and potentially enterprising women; the successful women entrepreneurs' perceptions on the sex equality in the field of entrepreneurship - this paper presents arguments and recommendations of specific policies meant to support the potential women entrepreneurship in Romania, as an engine to overcome the economic crisis and to reconnect to the regional development mechanism facilitated by the European Union's regional policy.

  10. Finite approximations in fluid mechanics II: DFG priority research programme results 1986-1988

    Science.gov (United States)

    Hirschel, Ernst Heinrich

    Recent advances in computational fluid dynamics and their practical applications in aircraft and automotive design, turbomachinery, heat exchangers and furnaces, and atmospheric modeling are discussed, summarizing the results of studies undertaken in the second half of a DFG-sponsored research program (1986-1988). Topics addressed include a vortex-lattice method for vortex-sheet roll-up and wing-vortex interaction, FEM extrapolation techniques for Stokes and Navier-Stokes flow over a backward-facing step, a method of characteristics for the incompressible Navier-Stokes equations, and unsteady separating flow on an oscillating airfoil. Consideration is given to Lagrangian and BEM approaches for viscous compressible flow, a close-coupled zonal solution for viscous flows, turbomachine calculations with an unstructured-grid FEM, hypersonic flow simulations for blunt bodies at incidence, and double-helical wave motion in supersonic reacting channel flow.

  11. Models of adopting the convicted to the imprisonment conditions – the results of my own research

    Directory of Open Access Journals (Sweden)

    Dorota Kanarek-Lizik

    2013-06-01

    Full Text Available Convicted who are sent to penitentiary, units in order to serve a sentence of imprisonment, are obliged to choose a proper technique (model of coping with the imprisonment discomfort and the way of minimizing discrepancy between the restricted and the outer world at the same time. In order to know these techniques, there has been a special questionnaire written which applies to a model of adopting the convicted to the imprisonment conditions. This questionnaire is based on the types of adaptations enumerated by E. Goffman and these are withdrawal, rebellion, settling down, cold calculation and conversion. In this article I introduced the results of my own research that concern the models of adopting the convicted to the imprisonment conditions. The survey included recidivists and the adults who serve a sentence of imprisonment for the first time.

  12. Charge It! Translating Electric Vehicle Research Results to Engage 7th and 8th Grade Girls

    Science.gov (United States)

    Egbue, Ona; Long, Suzanna; Ng, Ean-Harn

    2015-10-01

    Despite attempts to generate interest in science and technology careers, US students continue to show reduced interest in science, technology, engineering and mathematics (STEM) majors at the collegiate level. If girls are not engaged in STEM learning by the middle school level, studies show that they are even less likely to choose a science- or engineering-related major. This article presents results from a workshop for 7th and 8th grade girls designed to promote knowledge building in the area of sustainability and alternative energy use in transportation and to stimulate greater interest in STEM subjects. The workshop based on research conducted at University X focused on basic concepts of electric vehicles and electric vehicles' batteries. Tests were conducted to evaluate the students' knowledge and perceptions of electric vehicles and to determine the impact of the workshop. Early exposure to meaningful engineering experiences for these young girls may boost interest and the eventual pursuit of engineering and technology education paths.

  13. Employment and other selected personnel attributes in metallurgical and industrial enterprises of different size - research results

    Directory of Open Access Journals (Sweden)

    A. Pawliczek

    2015-10-01

    Full Text Available The presented paper deals with the issue of employment and other selected personnel attributes as employees’ affiliations, employees’ benefits, monitoring of employees’ satisfaction, monitoring of work productivity, investments into employees education and obstacles in hiring qualified human resources. The characteristics are benchmarked on the background of enterprise size based on the employees count in the year 2013. The relevant data were collected in Czech industrial enterprises, including metallurgical companies, with the help of university questionnaire research in order to induce synergy effect arising from mutual communication of academy-students-industry. The most important results are presented later in the paper, complemented with discussion based on relevant professional literature sources. The findings suggest that bigger companies check productivity and satisfaction and dismiss employees more frequently, unlike medium companies which do not reduce their workforce and solve the impact of crisis by decreased affiliations, reduced benefits and similar savings.

  14. Results from the Nuclear Plant Aging Research Program: Their use in inspection activities

    Energy Technology Data Exchange (ETDEWEB)

    Gunther, W.; Taylor, J. (Brookhaven National Lab., Upton, NY (USA))

    1990-09-01

    The US NCR's Nuclear Plant Aging Research (NPAR) Program has determined the susceptibility to aging of components and systems, and the potential for aging to impact plant safety and availability. The NPAR Program also identified methods for detecting and mitigating aging in components. This report describes the NPAR results which can enhance NRC inspection activities. Recommendations are provided for communicating pertinent information to NRC inspectors. These recommendations are based on a detailed assessment of the NRC's Inspection Program, and feedback from resident and regional inspectors as described within. Examples of NPAR report summaries and aging inspection guides for components and systems are included. 13 refs., 3 figs., 4 tabs.

  15. The value of evaluating parenting groups: a new researcher's perspective on methods and results.

    Science.gov (United States)

    Cabral, Judy

    2013-06-01

    The aim of this research project was to evaluate the impact of the Solihull Approach Understanding Your Child's Behaviour (UYCB) parenting groups on the participants' parenting practice and their reported behaviour of their children. Validated tools that met both the Solihull Child and Adolescent Mental Health Service (CAMHS) and academic requirements were used to establish what changes, if any, in parenting practice and children's behaviour (as perceived by the parent) occur following attendance of a UYCB parenting group. Independent evidence of the efficacy of the Solihull Approach UYCB programme was collated. Results indicated significant increases in self-esteem and parenting sense of competence; improvement in the parental locus of control; a decrease in hyperactivity and conduct problems and an increase in pro-social behaviour, as measured by the 'Strength and Difficulties' questionnaire. The qualitative and quantitative findings corroborated each other, demonstrating the impact and effectiveness of the programme and supporting anecdotal feedback on the success of UYCB parenting groups.

  16. The Main Results and the Perspectives in the Researches at SSRT

    Institute of Scientific and Technical Information of China (English)

    G. Y. Smolkov; S. V. Lesovoy; V. G. Zandanov; A. T. Altyntsev; A.V. Gubin

    2005-01-01

    In this report briefly presented the contemporary state of the experimental base of Radio Astrophysical Observatory (RAO) of the Institute of Solar-Terrestrial Physics (ISTP), the methodology of radioheliographic monitoring of the solar corona, the SSRT database, the RAO Web-pages, factors limiting the effective use of SSRT. Here are formulated the original results of the basic directions of the solar activity researches and the problems solutions on SSRT: (1) active regions at various development stages, morphology, modeling,signs of energy accumulation and flares buildup, forecast of powerful flares; (2) scenario, topology and the fine temporal picture of flares development, signs of primary energy release, radio emission mechanisms, scatter effects of radio emission in turbulent corona, energetic particles fluxes; (3) filaments; (4) CME with the localization of their initiation at the solar disk background, development scenario of filament activation + CME +flare; (5) coronal holes, and (6) bright coronal points.

  17. RESEARCH ABOUT RESULTS REPRODUTIBILITY AND ABRASIVE PARTICLES FRAGMENTATION IN BALL-CRATERING TESTS

    Directory of Open Access Journals (Sweden)

    Ronaldo Câmara Cozza

    2013-06-01

    Full Text Available The micro-abrasive wear tests by rotating ball (crater wear have played an important role in abrasive wear researches. In this type of test, the contact between a specimen and a ball on rotating motion and abrasive particles supplied between these two elements, results in a crater on the specimen, based on which the abrasive wear behaviour is analysed. The purpose of this work is to study results the reprodutibility and the silicon carbide (SiC abrasive particles fragmentation during micro-abrasive wear tests. Tests were conducted with carburized AISI 1010 steel balls and high speed steel specimens, “with” and “without” titanium nitride (TiN coatings. The abrasive slurry was prepared with black silicon carbide (average particle size of 5 µm and distilled water. Grooving abrasion is related with lower reprodutibility results. For the test conditions of this work, no abrasive particles fragmentation was observed, independently of the sliding distance, what is justified, among others factors, by the low normal force applied.

  18. Statement of principles on the return of research results and incidental findings in paediatric research: a multi-site consultative process.

    Science.gov (United States)

    Sénécal, Karine; Rahimzadeh, Vasiliki; Knoppers, Bartha M; Fernandez, Conrad V; Avard, Denise; Sinnett, Daniel

    2015-12-01

    This paper proposes a set of recommendations for the return of research results and incidental findings in paediatrics. The Network of Applied Genetic Medicine of Quebec spearheaded the initiative to develop the Statement of Principles on the Return of Research Results and Incidental Findings, which was the result of a consultation process with clinical and research experts in the field. To formulate the Statement of Principles, the authors (i) reviewed empirical and grey literature on the return of research results and incidental findings in Europe and Canada, (ii) conducted a qualitative study of stakeholder groups, (iii) developed, and (iv) validated the recommendations through consultations with the stakeholder groups. The Statement of Principles provides a useful disclosure tool for deciding when, and under what circumstances to return research results and incidental findings. It addresses the issue of return of results in genetic research generally, and has also specific principles for various research contexts, including paediatric research. It delineates ethical issues unique to paediatric research, and provides a framework to guide research ethics committees as well as the research community in addressing these issues.

  19. Determination of the wine preservative sulphur dioxide with cyclic voltammetry using inkjet printed electrodes.

    Science.gov (United States)

    Schneider, Marion; Türke, Alexander; Fischer, Wolf-Joachim; Kilmartin, Paul A

    2014-09-15

    During winemaking sulphur dioxide is added to prevent undesirable reactions. However, concerns over the harmful effects of sulphites have led to legal limits being placed upon such additives. There is thus a need for simple and selective determinations of sulphur dioxide in wine, especially during winemaking. The simultaneous detection of polyphenols and sulphur dioxide, using cyclic voltammetry at inert electrodes is challenging due to close oxidation potentials. In the present study, inkjet printed electrodes were developed with a suitable voltammetric signal on which the polyphenol oxidation is suppressed and the oxidation peak height for sulphur dioxide corresponds linearly to the concentration. Different types of working electrodes were printed. Electrodes consisting of gold nanoparticles mixed with silver showed the highest sensitivity towards sulphur dioxide. Low cost production of the sensor elements and ultra fast determination of sulphur dioxide by cyclic voltammetry makes this technique very promising for the wine industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. EC-FORC: A New Cyclic Voltammetry Based Method for Examining Phase Transitions and Predicting Equilibrium

    CERN Document Server

    Hamad, Ibrahim Abou; Novotny, Mark A; Rikvold, Per Arne

    2007-01-01

    We propose a new, cyclic-voltammetry based experimental technique that can not only differentiate between discontinuous and continuous phase transitions in an adsorbate layer, but also quite accurately recover equilibrium behavior from dynamic analysis of systems with a continuous phase transition. The Electrochemical first-order reversal curve (EC-FORC) diagram for a discontinuous phase transition (nucleation and growth), such as occurs in underpotential deposition, is characterized by a negative region, while such a region does not exist for a continuous phase transition, such as occurs in the electrosorption of Br on Ag(100). Moreover, for systems with a continuous phase transition, the minima of the individual EC-FORCs trace the equilibrium curve, even at very high scan rates. Since obtaining experimental data for the EC-FORC method would require only a simple reprogramming of the potentiostat used in conventional cyclic-voltammetry experiments, we believe that this method has significant potential for ea...

  1. Cyclic Voltammetry and Impedance Spectroscopy Behavior Studies of Polyterthiophene Modified Electrode

    Directory of Open Access Journals (Sweden)

    Naima Maouche

    2011-01-01

    Full Text Available We present in this work a study of the electrochemical behaviour of terthiophene and its corresponding polymer, which is obtained electrochemically as a film by cyclic voltammetry (CV on platinum electrode. The analysis focuses essentially on the effect of two solvents acetonitrile and dichloromethane on the electrochemical behaviour of the obtained polymer. The electrochemical behavior of this material was investigated by cyclic voltammetry and electrochemical impedance spectroscopy (EIS. The voltammograms show that the film of polyterthiophene can oxide and reduce in two solutions; in acetonitrile, the oxidation current intensity is more important than in dichloromethane. The impedance plots show the semicircle which is characteristic of charge-transfer resistance at the electrode/polymer interface at high frequency and the diffusion process at low frequency.

  2. Determination of Norfloxacin by square-wave adsorptive voltammetry on a glassy carbon electrode.

    Science.gov (United States)

    Ghoneim, M M; Radi, A; Beltagi, A M

    2001-05-01

    The adsorptive and electrochemical behavior of norfloxacin on a glassy carbon electrode were investigated by cyclic and square-wave voltammetry. Cyclic voltammetric studies indicated that the process was irreversible and fundamentally controlled by adsorption. To obtain a good sensitivity, the solution conditions and instrumental parameters were studied using square-wave voltammetry. In acetate buffer of pH 5.0, norfloxacin gave a sensitive adsorptive oxidative peak at 0.920 V (versus Ag-AgCl). Applicability to measurement of norfloxacin at submicromolar levels in urine samples was illustrated. The peak current was linear with the norfloxacin concentration in the range 5-50 microg ml(-1) urine. The detection limit was 1.1 microg ml(-1) urine.

  3. Anodic stripping voltammetry of silver nanoparticles: aggregation leads to incomplete stripping.

    Science.gov (United States)

    Cloake, Samantha J; Toh, Her Shuang; Lee, Patricia T; Salter, Chris; Johnston, Colin; Compton, Richard G

    2015-02-01

    The influence of nanoparticle aggregation on anodic stripping voltammetry is reported. Dopamine-capped silver nanoparticles were chosen as a model system, and melamine was used to induce aggregation in the nanoparticles. Through the anodic stripping of the silver nanoparticles that were aggregated to different extents, it was found that the peak area of the oxidative signal corresponding to the stripping of silver to silver(I) ions decreases with increasing aggregation. Aggregation causes incomplete stripping of the silver nanoparticles. Two possible mechanisms of 'partial oxidation' and 'inactivation' of the nanoparticles are proposed to account for this finding. Aggregation effects must be considered when anodic stripping voltammetry is used for nanoparticle detection and quantification. Hence, drop casting, which is known to lead to aggregation, is not encouraged for preparing electrodes for analytical purposes.

  4. Ozone and UV research at Finnish Meteorological Inst.: review of selected results

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P.; Koskela, T.; Damski, J.; Supperi, A. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E. [Finnish Meteorologican Inst., Sodankylae (Finland). Sodankylae Observatory; Ginzburg, M. [Servicio Meteorologico Nacional, Buenos Aires (Argentina); Dijkhuis, J.L. [Finnish Meteorological Inst., Helsinki (Finland). EUMETSAT

    1995-12-31

    Ozone and UV radiation research have become an important part of atmospheric research at Finnish Meteorological Institute after the discovery of chlorine based ozone loss in the Antarctic stratosphere

  5. Electrode Calibration with a Microfluidic Flow Cell for Fast-scan Cyclic Voltammetry

    OpenAIRE

    Sinkala, Elly; McCutcheon, James E.; Schuck, Matt; Schmidt, Eric; Roitman, Mitchell F.; Eddington, David T.

    2012-01-01

    Fast-scan cyclic voltammetry (FSCV) is a common analytical electrochemistry tool used to measure chemical species. It has recently been adapted for measurement of neurotransmitters such as dopamine in awake and behaving animals (in vivo). Electrode calibration is an essential step in FSCV to relate observed current to concentration of a chemical species. However, existing methods require multiple components, which reduce the ease of calibrations. To this end, a microfluidic flow cell (µFC) wa...

  6. EC-FORC: A New Cyclic Voltammetry Based Method for Examining Phase Transitions and Predicting Equilibrium

    OpenAIRE

    2007-01-01

    We propose a new, cyclic-voltammetry based experimental technique that can not only differentiate between discontinuous and continuous phase transitions in an adsorbate layer, but also quite accurately recover equilibrium behavior from dynamic analysis of systems with a continuous phase transition. The Electrochemical first-order reversal curve (EC-FORC) diagram for a discontinuous phase transition (nucleation and growth), such as occurs in underpotential deposition, is characterized by a neg...

  7. Detection of heavy metals in biological samples through anodic stripping voltammetry

    OpenAIRE

    Buzea, Vlad; Florescu, Monica; Badea, Mihaela

    2012-01-01

    The toxicological aspects due to the presence of heavy metals in biological samples impose to have accurate and rapid methods for their detection. This paper is aimed to review approaches to anodic stripping voltammetry (ASV) determination of several heavy metals (lead, cadmium, copper, mercury, zinc) in biological matrices (blood, urine, saliva, tissue sample). Analytical performances (LOD, data linearity range, sensitivity) of the reviewed methods were presented for several electrochemical ...

  8. New aspects of the electrochemical-catalytic (EC’) mechanism in square-wave voltammetry

    OpenAIRE

    Gulaboski, Rubin; Mirceski, Valentin

    2015-01-01

    Several new theoretical aspects of the electrocatalytic (regenerative) EC’ mechanism under conditions of square-wave (SWV) and staircase cyclic voltammetry (SCV) are presented. Elaborating the effect of the rate of the catalytic reaction in the diffusion-controlled catalytic mechanism (diffusional EC’ mechanism) and surface catalytic mechanism (surface EC’ mechanism), we refer to several phenomena related to the shift of the position and the half-peak width of the net peak in ...

  9. Glyphosate detection with ammonium nitrate and humic acids as potential interfering substances by pulsed voltammetry technique

    OpenAIRE

    MARTÍNEZ GIL, PABLO; Laguarda Miró, Nicolás; Soto Camino, Juan; Masot Peris, Rafael

    2013-01-01

    Pulsed voltammetry has been used to detect and quantify glyphosate on buffered water in presence of ammonium nitrate and humic substances. Glyphosate is the most widely used herbicide active ingredient in the world. It is a non-selective broad spectrum herbicide but some of its health and environmental effects are still being discussed. Nowadays, glyphosate pollution in water is being monitored but quantification techniques are slow and expensive. Glyphosate wastes are often detected in count...

  10. The redox status of experimental hemorrhagic shock as measured by cyclic voltammetry.

    Science.gov (United States)

    Mittal, Anubhav; Göke, Friederike; Flint, Richard; Loveday, Benjamin P T; Thompson, Nichola; Delahunt, Brett; Kilmartin, Paul A; Cooper, Garth J S; MacDonald, Julia; Hickey, Anthony; Windsor, John A; Phillips, Anthony R J

    2010-05-01

    Hemorrhagic shock (HS) leads to reactive oxygen species production. However, clinicians do not have access to bedside measurements of the redox status during HS. Cyclic voltammetry (CyV) is a simple electrochemical method of measuring redox status. The aims of this study were to 1) report the first application of cyclic voltammetry to measure the acute changes in serum redox status after HS, 2) to contrast it with another severe systemic disease with a different redox pathology (acute pancreatitis [AP]), and 3) to describe the response of CyV over time in a resolving model of AP. In the acute study, 24 male Wistar rats were randomized into three groups: groups 1 (control), 2 (AP), and 3 (HS). In the time-course study, 28 rats were randomized to a sham-control as well as 6 and 24 h post-AP cohorts, respectively.Cyclic voltammetry was performed using a three-electrode system. In the acute study, the first and second voltammetric peaks increased significantly in HS. In contrast, within the AP group, only the first voltammetric peak showed a significant increase. The first voltammetric peak correlated with plasma protein carbonyls (PCs) and with thiobarbituric acid-reactive substances, whereas the second voltammetric peak correlated positively with plasma protein carbonyls. In the second study, the first voltammetric peak correlated with physiological improvements. Here, we showed that serum CyV could respond to the serum redox change in HS and AP. Cyclic voltammetry warrants evaluation as a potential real-time beside measure of a patient's redox status during shock.

  11. A one-dimensional stochastic approach to the study of cyclic voltammetry with adsorption effects

    OpenAIRE

    Adib J. Samin

    2016-01-01

    In this study, a one-dimensional stochastic model based on the random walk approach is used to simulate cyclic voltammetry. The model takes into account mass transport, kinetics of the redox reactions, adsorption effects and changes in the morphology of the electrode. The model is shown to display the expected behavior. Furthermore, the model shows consistent qualitative agreement with a finite difference solution. This approach allows for an understanding of phenomena on a microscopic level ...

  12. Dating copper-based archaeological materials using the voltammetry of microparticles

    OpenAIRE

    Doménech-Carbó, Antonio; Capelo, Sofia; Doménech-Carbó, María Teresa

    2014-01-01

    The voltammetry of microparticles, an electrochemical technique providing information on the composition of archaeological materials using an essentially non invasive analysis [1,2] was previously applied for dating lead-based materials [3,4]. It is described the application of this methodology for dating copper-based archaeological materials based on a theoretical model for long term metal corrosion [5]. Dating is based on the measurement of the voltammetric signals of cuprite and tenorite f...

  13. Cathodic stripping voltammetry of cysteine using silver and copper solid amalgam electrodes.

    Science.gov (United States)

    Yosypchuk, B; Novotný, L

    2002-04-01

    Silver and copper solid amalgam electrodes (modified with mercury meniscus and based on amalgamation of fine metallic powder) have been successfully tested for cathodic stripping voltammetry of cysteine. In the case of the silver solid amalgam electrode AgSAE the relative standard deviation (RSD) and the detection limit (3 SD) reached +/-2.3% and 3x10(-9) mol l(-1) cysteine, respectively.

  14. Square-Wave Voltammetry of Cathodic Stripping Reactions. Diagnostic Criteria, Redox Kinetic Measurements, and Analytical Applications

    OpenAIRE

    Gulaboski, Rubin; Mirceski, Valentin; Komorsky-Lovrić, Šebojka; Lovrić, Milivoj

    2004-01-01

    A comparative study of different types of cathodic stripping reactions under conditions of square-wave voltammetry is presented. Cathodic stripping processes involving reactions of second order as well as reactions coupled by adsorption of the reacting ligand are analyzed The inherent parameters, controlling the overall voltammetric behavior of each cathodic stripping electrode reaction are derived. The criteria for qualitative distinguishing of each mechanism are established as w...

  15. Porosity Study of Hybrid Silica Mesostructure in Aluminium Oxide Membrane Columnar by Cyclic Voltammetry Method

    Directory of Open Access Journals (Sweden)

    M.N. Jalil

    2011-12-01

    Full Text Available Silica mesostructure has been grown within with a porous aluminium oxide membrane columnar material (hybrid-AOM. This was prepared using a sol-gel technique with Pluronic P123 triblock copolymer as the structure-directing agent and tetraethyl orthosilicate as the inorganic source. The porosity of the hybrid-AOM after ethanol extraction was calculated from the cyclic voltammetry response of a neutral probe (FcMeOH, using Randles-Sevčik equation.

  16. Graphene electroanalysis: inhibitory effects in the stripping voltammetry of cadmium with surfactant free graphene.

    Science.gov (United States)

    Brownson, Dale A C; Lacombe, Alexandre C; Kampouris, Dimitrios K; Banks, Craig E

    2012-01-21

    We explore the use of surfactant free graphene towards the electroanalytical sensing of cadmium(II) ions via anodic stripping voltammetry. In line with literature methodologies, we modify an electrode substrate which exhibits relatively fast electron transfer with commercially available graphene which is free from surfactants. Surprisingly, we find that graphene reduces the analytical performance and hence inhibits the electrochemical detection of cadmium(II) ions, with calibration plots in model aqueous solutions revealing no advantages of employing graphene in this analytical context.

  17. Simultaneous identification of lead pigments and binding media in paint samples using voltammetry of microparticles

    OpenAIRE

    DOMENECH CARBO, ANTONIO; Domenech Carbo, Mª Teresa; Mas Barberà, Xavier; Ciarrocci, Julia

    2007-01-01

    Voltammetry of microparticles is applied to the simultaneous determination of lead pigments and binding media in paint samples. The mechanical attachment of a few nanograms of sample to a paraffin-impregnated graphite electrode produced well-defined square wave voltammetric responses for model paint specimens containing lead white, minium and Naples yellow associated with linseed, sunflower and poppy oils and casein, egg, and bovine gelatin. The use of a multiparametric fitting of the electro...

  18. Preferences Regarding Return of Genomic Results to Relatives of Research Participants, Including after Participant Death: Empirical Results from a Cancer Biobank.

    Science.gov (United States)

    Breitkopf, Carmen Radecki; Petersen, Gloria M; Wolf, Susan M; Chaffee, Kari G; Robinson, Marguerite E; Gordon, Deborah R; Lindor, Noralane M; Koenig, Barbara A

    2015-01-01

    Data are lacking with regard to participants' perspectives on return of genetic research results to relatives, including after the participant's death. This paper reports descriptive results from 3,630 survey respondents: 464 participants in a pancreatic cancer biobank, 1,439 family registry participants, and 1,727 healthy individuals. Our findings indicate that most participants would feel obligated to share their results with blood relatives while alive and would want results to be shared with relatives after their death.

  19. A Grounded Theory of Inductive Qualitative Research Education: Results of a Meta-Data-Analysis

    Science.gov (United States)

    Cooper, Robin; Chenail, Ronald J.; Fleming, Stephanie

    2012-01-01

    This paper reports on the first stage of a meta-study conducted by the authors on primary research published during the last thirty years that focused on discovering the experiences of students learning qualitative research. The authors carried out a meta-analysis of the findings of students' experiences learning qualitative research included in…

  20. Recent Ocean Literacy Research in United States Public Schools: Results and Implications

    Science.gov (United States)

    Plankis, Brian J.; Marrero, Meghan E.

    2010-01-01

    Recent research conducted on adults in the United States indicates low ocean literacy (Ocean Project, 2009b, 1999), but there is a dearth of peer-reviewed research on K-12 students' ocean literacy. This paper presents two research studies that examined the ocean and environmental literacy of 464 K-12 students in five states. Like the majority of…

  1. Research culture and capacity in community health services: results of a structured survey of staff.

    Science.gov (United States)

    Friesen, Emma L; Comino, Elizabeth J

    2016-08-17

    Developing research capacity is recognised as an important endeavour. However, little is known about the current research culture, capacity and supports for staff working in community-based health settings. A structured survey of Division of Community Health staff was conducted using the research capacity tool. The survey was disseminated by email and in paper format. Quantitative data were analysed using descriptive statistics. Qualitative data were analysed thematically. In total, 109 usable responses were received, giving a response rate of 26%. Respondents were predominately nurses (n=71, 65.7%), with ~50% reporting post-graduate vocational qualifications. The highest levels of skills or organisational success were in using evidence to plan, promote and guide clinical practice. Most participants were unsure of organisational and team level skills and success at generating research. Few reported recent experience in research-generating activities. Barriers to undertaking research included lack of skills, time and access to external support and funding. Lack of skills and success in accessing external funding and resources to protect research time or to 'buy-in' technical expertise appeared to exacerbate these barriers. Community health staff have limited capacity to generate research with current levels of skill, funding and time. Strategies to increase research capacity should be informed by knowledge of clinicians' research experience and interests, and target development of skills to generate research. Resources and funding are needed at the organisational and team levels to overcome the significant barriers to research generation reported.

  2. Synthesizing Results From Empirical Research on Computer-Based Scaffolding in STEM Education

    Science.gov (United States)

    Belland, Brian R.; Walker, Andrew E.; Kim, Nam Ju; Lefler, Mason

    2016-01-01

    Computer-based scaffolding assists students as they generate solutions to complex problems, goals, or tasks, helping increase and integrate their higher order skills in the process. However, despite decades of research on scaffolding in STEM (science, technology, engineering, and mathematics) education, no existing comprehensive meta-analysis has synthesized the results of these studies. This review addresses that need by synthesizing the results of 144 experimental studies (333 outcomes) on the effects of computer-based scaffolding designed to assist the full range of STEM learners (primary through adult education) as they navigated ill-structured, problem-centered curricula. Results of our random effect meta-analysis (a) indicate that computer-based scaffolding showed a consistently positive (ḡ = 0.46) effect on cognitive outcomes across various contexts of use, scaffolding characteristics, and levels of assessment and (b) shed light on many scaffolding debates, including the roles of customization (i.e., fading and adding) and context-specific support. Specifically, scaffolding’s influence on cognitive outcomes did not vary on the basis of context-specificity, presence or absence of scaffolding change, and logic by which scaffolding change is implemented. Scaffolding’s influence was greatest when measured at the principles level and among adult learners. Still scaffolding’s effect was substantial and significantly greater than zero across all age groups and assessment levels. These results suggest that scaffolding is a highly effective intervention across levels of different characteristics and can largely be designed in many different ways while still being highly effective.

  3. Electrochemical Studies of 1,4-Bis[2-(2-pyridyl)-vinyl] Benzene and 1,4-Bis[2-(4-pyridyl) vinyl] Benzene Laser Dyes via Cyclic Voltammetry, Convolutive Voltammetry and Digital Simulation Methods

    Institute of Scientific and Technical Information of China (English)

    EL-DALY, Samy A; EL-HALLAG,Ibrahirn S; EBEED, Ezeiny M; GHONEIM, Mohamed M

    2009-01-01

    Electrochemical properties of two diolefinic laser dyes namely 1,4-bis[2-(2-pyddyl)-vinyl] benzene (2PVB) and 1,4-bis[2-(4-pyridyl) vinyl] benzene (4PVB) have been investigated using cyclic voltammetry and convolutive voltammetry combined with digital simulation at a platinum electrode in 0.1 mol/L tetrabutyl ammonium perchlo-rate (TBAP) in the two different solvents acetonitrile (CH3CN) and dimethylformamide (DMF). The species were reduced via consumption of two sequential electrons to form radical anion and dianion. In switching the potential to positive direction, the two compounds were oxidized by loss of one electron, which was followed by a fast isomeri-sation process. The electrode reaction pathway and the electrochemical parameters of the investigated compounds were determined using cyclic voltammetry. The extracted electrochemical parameters were verified and confirmed via digital simulation and convolutive voltammetry methods.

  4. Copper-based electrochemical sensor with palladium electrode for cathodic stripping voltammetry of manganese.

    Science.gov (United States)

    Kang, Wenjing; Pei, Xing; Bange, Adam; Haynes, Erin N; Heineman, William R; Papautsky, Ian

    2014-12-16

    In this work, we report on the development of a palladium-based, microfabricated point-of-care electrochemical sensor for the determination of manganese using square wave cathodic stripping voltammetry. Heavy metals require careful monitoring, yet current methods are too complex for a point-of-care system. Voltammetry offers an attractive approach to metal detection on the microscale, but traditional carbon, gold, or platinum electrodes are difficult or expensive to microfabricate, preventing widespread use. Our sensor uses palladium working and auxiliary electrodes and integrates them with a copper-based reference electrode for simple fabrication and compatibility with microfabrication and printed circuit board processing, while maintaining competitive performance in electrochemical detection. Copper electrodes were prepared on glass substrate using a combination of microfabrication procedures followed by electrodeposition of palladium. The disposable sensor system was formed by bonding a poly(dimethylsiloxane) (PDMS) well to the glass substrate. Cathodic stripping voltammetry of manganese using our new disposable palladium-based sensors exhibited 334 nM (18.3 ppb) limit of detection in borate buffer. The sensor was used to demonstrate manganese determination in natural water samples from a pond in Burnet Woods, located in Cincinnati, OH, and the Ohio River.

  5. Toward an in situ phosphate sensor in seawater using Square Wave Voltammetry.

    Science.gov (United States)

    Barus, C; Romanytsia, I; Striebig, N; Garçon, V

    2016-11-01

    A Square Wave Voltammetry electrochemical method is proposed to measure phosphate in seawater as pulse techniques offer a higher sensitivity as compared to classical cyclic voltammetry. Chronoamperometry cannot be either adapted for an in situ sensor since this method requires to have controlled convection which will be impossible in a miniaturised sensor. Tests and validation of Square Wave Voltammetry parameters have been performed using an open cell and for the first time with a small volume (<400µL) laboratory prototypes. Two designs of prototypes have been compared. Using high frequency (f=250Hz) allows to obtain a linear behaviour between 0.1 and 1µmolL(-1) with a very low limit of detection of 0.05 µmolL(-1) after 60min of complexation waiting time. In order to obtain a linear regression for a larger concentration range i.e. 0.25-4µmolL(-1), a lower frequency of 2.5Hz is needed. A limit of detection of 0.1µmolL(-1) is obtained in this case after 30min of complexation waiting time for the peak measured at E=0.12V. Changing the position of the molybdenum electrode for the complexation step and moving the detection into another electrochemical cell allow to decrease the reaction time down to 5min. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Credits to Graduation: A Comparison of Transfer Graduates and Secondary School Graduates at BC Research Universities. Research Results

    Science.gov (United States)

    Pendleton, Sham

    2010-01-01

    This study examines the number of credits earned at graduation for two groups: those who graduated with a baccalaureate degree and who were admitted as transfer students and those admitted as secondary school students to one of the four BC research universities [Simon Fraser University (SFU), University of British Columbia, Vancouver (UBC),…

  7. A Multi-Disciplinary University Research Initiative in Hard and Soft Information Fusion: Overview, Research Strategies and Initial Results

    Science.gov (United States)

    2010-07-01

    Thrusts addressed are framed around the major functional components of the JDL Fusion Process; these include: 1. Source Characterization of Soft...Level 2 data fusion environment. The primary Research Thrusts addressed are framed around the major functional components of the JDL Fusion Process

  8. What Really Happens in Quantitative Group Research? Results of a Content Analysis of Recent Quantitative Research in "JSGW"

    Science.gov (United States)

    Boyle, Lauren H.; Whittaker, Tiffany A.; Eyal, Maytal; McCarthy, Christopher J.

    2017-01-01

    The authors conducted a content analysis on quantitative studies published in "The Journal for Specialists in Group Work" ("JSGW") between 2012 and 2015. This brief report provides a general overview of the current practices of quantitative group research in counseling. The following study characteristics are reported and…

  9. Implementation of research results to prevent land degradation in viticultural areas

    Science.gov (United States)

    Marqués Pérez, Maria Jose; Bienes, Ramon; de Benito, Alejandro; Velasco, Ana

    2013-04-01

    This study shows the lack of interest of land users to establish contact with scientific institutions and their reluctance to change their traditional way to manage their soils. It is conducted in Madrid and Castilla La Mancha, Spain, where the production of wine is an important source of income. The basic research was dealing with sustainable land management in sloping vineyards to prevent soil degradation. The usual reduced tillage practice in the area is compared with different cover grasses in the inter-rows of vines. The results demonstrate that these managements are able to increase soil organic matter, improve infiltration, reduce runoff and soil loss and increase soil aggregate stability. Nevertheless a decrease in production is noticed in some permanent cover treatments. A survey to know the feasibility of implementation of this sustainable land management was conducted. Less than 5% of vine growers coming to cellars and cooperatives were willing to be interviewed. Finally 64 vine growers answered a questionnaire regarding different aspects of their environmental concerns, age, land management practices and economic situation. The majority of respondents (82%) are worried about erosion problems in their sloping vineyards. They were informed about the results of the abovementioned project but only 32% of them would change the cultivation by grasses in the inter-rows. The respondents were not old (72% below 50 years old), and the agriculture was not their first activity (69% had other different sources of income). It is remarkable that they have some misunderstandings and lack of knowledge in questions regarding soil conservation. Only 3% of them receive some kind of economic aid from the institutions to avoid land degradation. This could be related to the small or medium size of their lands as 87% of them have plots smaller than 50 ha. The extension services and policy makers have to face this situation to achieve the proper implementation of scientific

  10. First results from the LUX dark matter experiment at the Sanford underground research facility.

    Science.gov (United States)

    Akerib, D S; Araújo, H M; Bai, X; Bailey, A J; Balajthy, J; Bedikian, S; Bernard, E; Bernstein, A; Bolozdynya, A; Bradley, A; Byram, D; Cahn, S B; Carmona-Benitez, M C; Chan, C; Chapman, J J; Chiller, A A; Chiller, C; Clark, K; Coffey, T; Currie, A; Curioni, A; Dazeley, S; de Viveiros, L; Dobi, A; Dobson, J; Dragowsky, E M; Druszkiewicz, E; Edwards, B; Faham, C H; Fiorucci, S; Flores, C; Gaitskell, R J; Gehman, V M; Ghag, C; Gibson, K R; Gilchriese, M G D; Hall, C; Hanhardt, M; Hertel, S A; Horn, M; Huang, D Q; Ihm, M; Jacobsen, R G; Kastens, L; Kazkaz, K; Knoche, R; Kyre, S; Lander, R; Larsen, N A; Lee, C; Leonard, D S; Lesko, K T; Lindote, A; Lopes, M I; Lyashenko, A; Malling, D C; Mannino, R; McKinsey, D N; Mei, D-M; Mock, J; Moongweluwan, M; Morad, J; Morii, M; Murphy, A St J; Nehrkorn, C; Nelson, H; Neves, F; Nikkel, J A; Ott, R A; Pangilinan, M; Parker, P D; Pease, E K; Pech, K; Phelps, P; Reichhart, L; Shutt, T; Silva, C; Skulski, W; Sofka, C J; Solovov, V N; Sorensen, P; Stiegler, T; O'Sullivan, K; Sumner, T J; Svoboda, R; Sweany, M; Szydagis, M; Taylor, D; Tennyson, B; Tiedt, D R; Tripathi, M; Uvarov, S; Verbus, J R; Walsh, N; Webb, R; White, J T; White, D; Witherell, M S; Wlasenko, M; Wolfs, F L H; Woods, M; Zhang, C

    2014-03-07

    The Large Underground Xenon (LUX) experiment is a dual-phase xenon time-projection chamber operating at the Sanford Underground Research Facility (Lead, South Dakota). The LUX cryostat was filled for the first time in the underground laboratory in February 2013. We report results of the first WIMP search data set, taken during the period from April to August 2013, presenting the analysis of 85.3 live days of data with a fiducial volume of 118 kg. A profile-likelihood analysis technique shows our data to be consistent with the background-only hypothesis, allowing 90% confidence limits to be set on spin-independent WIMP-nucleon elastic scattering with a minimum upper limit on the cross section of 7.6 × 10(-46) cm(2) at a WIMP mass of 33 GeV/c(2). We find that the LUX data are in disagreement with low-mass WIMP signal interpretations of the results from several recent direct detection experiments.

  11. Magnetic anomalies of steel drums: a review of the literature and research results of the INGV

    Directory of Open Access Journals (Sweden)

    Marco Marchetti

    2013-04-01

    Full Text Available The detection and evaluation of the status of disposal sites that contain hazardous waste materials is becoming an increasingly important element in environmental investigations. Close cooperation between the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Volcanology and Geophysics in Rome and the Italian environmental police has resulted in numerous underground investigations of different buried materials. Among the geophysical investigation tools, magnetometry is the most effective, rapid and precise of all of the geophysical methods for localizing buried steel drums. Analysis of magnetic map anomalies can provide a variety of information about buried materials, including extension, distribution and depth, with processing of the acquired magnetic data. This information is also very useful in case of excavations that are aimed at the recovery of hazardous waste. This study determines the most relevant analyses reported in the literature, with modeling of magnetometric methods for environmental applications both theoretically and experimentally. Some studies and research results achieved by the INGV in relation to magnetic anomalies produced by buried steel drums are also reported, as found in field operations and as achieved from test sites.

  12. Research results from a high pressure/temperature dry-feeding coal gasifier for IGCC systems

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Y.S.; Lee, K.B.; Lee, H.G.; Chung, S.W.; Park, S.K. [Institute for Advanced Engineering, Yongin (Korea, Republic of)

    1998-05-01

    Research results obtained from a 3 ton/day-class coal gasifier were illustrated. Among many things, the shape and inner structure of slags that were obtained from a 3 ton/day-class gasifier and from a commercial-scale gasifier for the identical coal were compared to identify any gasifier-size effect. Slags from both gasifiers exhibited a similar size and also the same indication of forming vesiculation inside the structure. Slags possessed normally less than 0.3% carbon content while showing no elutriation of heavy metals by water. Inner structure of slags produced by gasification shows an amorphous characteristics whereas combusted ash exhibits a clear indication of crystal nature by minerals, explaining that high temperature gasifier conditions of above 1400 deg. C melt minerals to form interwined slag structure with heavy metals. Another area of the study was on simulation of the gasifier and the IGCC plant. The 3 ton/day-class plant was simulated 3-dimensionally, allowing walk-through of the plant via a software. Detailed static and dynamic process simulations were also performed. Some of these results were illustrated. (author). 7 figs.

  13. Square-wave voltammetry assays for glycoproteins on nanoporous gold

    Science.gov (United States)

    Pandey, Binod; Bhattarai, Jay K.; Pornsuriyasak, Papapida; Fujikawa, Kohki; Catania, Rosa; Demchenko, Alexei V.; Stine, Keith J.

    2014-01-01

    Electrochemical enzyme-linked lectinsorbent assays (ELLA) were developed using nanoporous gold (NPG) as a solid support for protein immobilization and as an electrode for the electrochemical determination of the product of the reaction between alkaline phosphatase (ALP) and p-aminophenyl phosphate (p-APP), which is p-aminophenol (p-AP). Glycoproteins or concanavalin A (Con A) and ALP conjugates were covalently immobilized onto lipoic acid self-assembled monolayers on NPG. The binding of Con A – ALP (or soybean agglutinin – ALP) conjugate to glycoproteins covalently immobilized on NPG and subsequent incubation with p-APP substrate was found to result in square-wave voltammograms whose peak difference current varied with the identity of the glycoprotein. NPG presenting covalently bound glycoproteins was used as the basis for a competitive electrochemical assay for glycoproteins in solution (transferrin and IgG). A kinetic ELLA based on steric hindrance of the enzyme-substrate reaction and hence reduced enzymatic reaction rate after glycoprotein binding is demonstrated using immobilized Con A–ALP conjugates. Using the immobilized Con A-ALP conjugate, the binding affinity of immunoglobulin G (IgG) was found to be 105 nM, and that for transferrin was found to be 650 nM. Minimal interference was observed in the presence of 5 mg mL−1 BSA as a model serum protein in both the kinetic and competitive ELLA. Inhibition studies were performed with methyl D-mannoside for the binding of TSF and IgG to Con A-ALP; IC50 values were found to be 90 μM and 286 μM, respectively. Surface coverages of proteins were estimated using solution depletion and the BCA protein concentration assay. PMID:24611035

  14. The CONSTANCES cohort, an epidemiological research infrastructure. Methods and results of the pilot phase

    Directory of Open Access Journals (Sweden)

    Marie Zins

    2013-06-01

    cohort of non-participants was set up and will be followed through the same national databases as participants.Results: a field-pilot was performed in 2010 in seven HSCs, which included about 3 500 subjects; it showed a satisfactory structure of the sample and a good validity of the collected data.Conclusions: the constitution of the full eligible sample begun in 2012 and the cohort will be completed by the end of 2017. A public call for ancillary research projects will be launched in 2014.

  15. Fisheries Oceanography in the Virgin Islands: Preliminary Results from a Collaborative Research Endeavor

    Science.gov (United States)

    Smith, R. H.; Gerard, T. L.; Johns, E. M.; Lamkin, J. T.

    2008-05-01

    A multi-species spawning aggregation located on the banks south of St. Thomas includes several economically important fish species, including dog snapper, yellowfin grouper, Nassau grouper, and tiger grouper. Increased fishing pressure on these banks has prompted the Caribbean Fisheries Council to take actions such as seasonally closing fishing grounds and establishing Marine Protected Areas (MPAs). Due to a lack of biological and oceanographic data for the region, these management decisions have been based on professional judgment rather than scientific data. In response to this situation, NOAA scientists from SEFSC and AOML began an interdisciplinary field study in the region in 2007. Research cruises utilize biological sampling techniques such as MOCNESS, neuston, and bongo trawl tows simultaneously with standard physical sampling methods such as CTD/LADCP casts, hull- mounted water velocity measurements, and Lagrangian drifter deployments. The three year project aims to determine how the unprotected banks of the Virgin Islands and surrounding region, the seasonally closed banks and MPAs, and near-shore areas are ecologically linked in terms of larval dispersal, transport, and life history patterns. This collaboration should produce an assessment, based on scientific data, of the effectiveness of Caribbean Research Council management decisions and suggest modifications and improvements to current policy. Additionally, this project will also provide fisheries independent data, and develop ecological indices which can be integrated into stock assessment models. Analysis of data gathered during the project's first research cruise is yielding preliminary results. A total of 26,809 fish larvae were collected from the Grammanik and Red Hind Banks and surrounding regions. Of this total, 585 Serranidae (grouper) and 93 Lutjanidae (snapper) larval specimens were collected. Typical sampling transects included near-shore, shelf-break, and offshore regimes. The most

  16. Psycho-social picture of sexually active adolescent girls: Results of research survey

    Directory of Open Access Journals (Sweden)

    Stanković Biljana

    2004-01-01

    Full Text Available In a demographic sense, adolescents are a population group which is yet to take part in birth giving. Therefore, their sexual behavior and especially sexual activity at early ages which is not only unfavorable from the aspect of the individual, meaning risk for psycho-physical health, but from the aspect of society as well, as regards population fertility, deserves special attention. This paper shows the results of in-depth research carried out in Belgrade from September 2001 to October 2002 with an aim to establish which factors determine a young person, of sixteen years old or younger, to become sexually active. It was carried out on a sample of 111 adolescent girls between 14 and 20 years old which turned to the Republic Family Planning Center Youth Counseling Clinic of the Institute for Mother and Child Health Care of Serbia. The research showed that sexual experience, realized at an early age was an integral part of development and maturing for the largest number of surveyed girls. In the largest number of cases it was a positive experience, induced by love and experienced with a partner, mainly of the same age, with which they were in a longer, stable relationship. Nevertheless, it could be concluded from the results obtained by the research that the surveyed girls could have more easily and efficiently solved their problems and dilemmas regarding sexuality had they had the possibility to obtain a better insight into their personal feelings and feelings of others at the right time, as well as developed social experience and experience in mastering control of their impulses. With a certain number of surveyed girls that would have meant a delay in their sexual activities to a later age. This also refers to the prevention of other risky behavior such as use of alcohol and drugs, which also have an influence on changing sexual behavior, making it more risky. It is important to stress that the surveyed adolescent girls themselves recognized the

  17. Analysis of 10-Year Training Results of Medical Students Using the Microvascular Research Center Training Program.

    Science.gov (United States)

    Onoda, Satoshi; Kimata, Yoshihiro; Sugiyama, Narushi; Tokuyama, Eijiro; Matsumoto, Kumiko; Ota, Tomoyuki; Thuzar, Moe

    2016-06-01

    Background In this article, we reviewed the training results of medical students using the Microvascular Research Center Training Program (MRCP), and proposed an ideal microsurgical training program for all individuals by analyzing the training results of medical students who did not have any surgical experience. Methods As of 2015, a total of 29 medical students completed the MRCP. In the most recent 12 medical students, the number of trials performed for each training stage and the number of rats needed to complete the training were recorded. Additionally, we measured the operating time upon finishing stage 5 for the recent six medical students after it became a current program. Results The average operating time upon finishing stage 5 for the recent six medical students was 120 minutes ± 11 minutes (standard deviation [SD]). The average vascular anastomosis time (for the artery and vein) was 52 minutes ± 2 minutes (SD). For the most recent 12 medical students, there was a negative correlation between the number of trials performed in the non-rat stages (stages 1-3) and the number of rats used in the rat stages (stages 4-5). Conclusion Analysis of the training results of medical students suggests that performing microsurgery first on silicon tubes and chicken wings saves animals' lives later during the training program. We believe that any person can learn the technique of microsurgery by performing 7 to 8 hours of training per day over a period of 15 days within this program setting.

  18. ``Hit and Run Research'' with ``Hit and Miss'' Results in Early Childhood Science Education

    Science.gov (United States)

    Fleer, Marilyn; Robbins, Jill

    2003-08-01

    Constructivism has provided us with a useful pedagogy and a powerful methodological framework for over twenty years. We now know a great deal about children's thinking. Can this research paradigm take us any further? Are we locked into a particular perspective about data gathering and categorising children's thinking? Have we tended to fit early childhood data into the 'accepted science education paradigm'? As early childhood researchers, we have found the wealth of research in science education research unable to provide solutions to some fundamental challenges we face when working with young children. This paper seeks to examine the established body of literature in science education research with a view to seeking out a more inclusive research approach to support early childhood science education. Examples of early childhood data within a range of contexts are presented to illustrate some of the challenges. Some of the issues that are raised may well be helpful to the field as a whole.

  19. Results for Phase I of the IAEA Coordinated Research Program on HTGR Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Strydom, Gerhard [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bostelmann, Friederike [Idaho National Lab. (INL), Idaho Falls, ID (United States); Yoon, Su Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-01-01

    The quantification of uncertainties in design and safety analysis of reactors is today not only broadly accepted, but in many cases became the preferred way to replace traditional conservative analysis for safety and licensing analysis. The use of a more fundamental methodology is also consistent with the reliable high fidelity physics models and robust, efficient, and accurate codes available today. To facilitate uncertainty analysis applications a comprehensive approach and methodology must be developed and applied. High Temperature Gas-cooled Reactors (HTGR) has its own peculiarities, coated particle design, large graphite quantities, different materials and high temperatures that also require other simulation requirements. The IAEA has therefore launched a Coordinated Research Project (CRP) on the HTGR Uncertainty Analysis in Modeling (UAM) in 2013 to study uncertainty propagation specifically in the HTGR analysis chain. Two benchmark problems are defined, with the prismatic design represented by the General Atomics (GA) MHTGR-350 and a 250 MW modular pebble bed design similar to the HTR-PM (INET, China). This report summarizes the contributions of the HTGR Methods Simulation group at Idaho National Laboratory (INL) up to this point of the CRP. The activities at INL have been focused so far on creating the problem specifications for the prismatic design, as well as providing reference solutions for the exercises defined for Phase I. An overview is provided of the HTGR UAM objectives and scope, and the detailed specifications for Exercises I-1, I-2, I-3 and I-4 are also included here for completeness. The main focus of the report is the compilation and discussion of reference results for Phase I (i.e. for input parameters at their nominal or best-estimate values), which is defined as the first step of the uncertainty quantification process. These reference results can be used by other CRP participants for comparison with other codes or their own reference

  20. Theoretical and experimental study of redox processes combined with adsorption phenomena under conditions of square-wave voltammetry

    OpenAIRE

    Gulaboski, Rubin

    2001-01-01

    Theoretical models of four electrode reactions coupled with adsorption phenomena under conditions of square-wave voltammetry are developed: simple surface redox reaction, surface catalytic reaction, cathodic stripping reaction of I order, and cathodic stripping reaction of II order.

  1. Examining the complex regulation and drug-induced plasticity of dopamine release and uptake using voltammetry in brain slices.

    Science.gov (United States)

    Ferris, Mark J; Calipari, Erin S; Yorgason, Jordan T; Jones, Sara R

    2013-05-15

    Fast scan cyclic voltammetry in brain slices (slice voltammetry) has been used over the last several decades to increase substantially our understanding of the complex local regulation of dopamine release and uptake in the striatum. This technique is routinely used for the study of changes that occur in the dopamine system associated with various disease states and pharmacological treatments, and to study mechanisms of local circuitry regulation of dopamine terminal function. In the context of this Review, we compare the relative advantages of voltammetry using striatal slice preparations versus in vivo preparations, and highlight recent advances in our understanding of dopamine release and uptake in the striatum specifically from studies that use slice voltammetry in drug-naïve animals and animals with a history of psychostimulant self-administration.

  2. Elluminate Artical: Research Results from BC’s Connected Learner’s Technology Projects

    Directory of Open Access Journals (Sweden)

    Elizabeth Childs

    2007-11-01

    Full Text Available The publisher of IRRODL, The Canadian Institute of Distance Education Research (CIDER, is pleased to provide links to a series of online seminars that took place over Spring 2007, using Elluminate. These interactive CIDER Sessions disseminate research emanating from North America's and Canada's vibrant DE research community, and we feel these archived recordings are highly relevant to many in the international distance education research community. To access these sessions, you must first download FREE software from Elluminate (http://www.elluminate.com/support/

  3. From Spatial Intelligence to Spatial Competences: The Results of Applied Geo-Research in Italian Schools

    Directory of Open Access Journals (Sweden)

    Emilia SARNO

    2012-08-01

    Full Text Available This contribution explains the connection between spatial intelligence and spatial competences and by indicating how the first is the cognitive matrix of abilities necessary to move in space as well as to represent it. Indeed, two are principal factors involved in the spatial intelligence: orientation and representation. Both are based on a close interaction between spatial thought and movement in space. I show the basic features of spatial intelligence through the analysis of specialist literature. This point, however, requires a further step to be taken into consideration: how can spatial intelligence be strengthened together with the related spatial competences? Moreover, which branch of knowledge is the most suitable to do so? By referring to the existing literature on the subject, we would like to indicate that geography has a pre-eminent role in dealing with the connection between man and space and as such it is the most suitable academic discipline to aid the development of spatial abilities through a series of precise didactic activities. The second part of this paper presents an experimental prototype of this kind of targeted teaching activity following the research-action method, an approach where theory and practice meet allowing a systematic collection of data. In effect, the stages of an experimental framework which has allowed the spatial intelligence of primary school children to be developed has been described and the methods of monitoring the results have also be illustrated.

  4. Research Initiatives and Preliminary Results In Automation Design In Airspace Management in Free Flight

    Science.gov (United States)

    Corker, Kevin; Lebacqz, J. Victor (Technical Monitor)

    1997-01-01

    The NASA and the FAA have entered into a joint venture to explore, define, design and implement a new airspace management operating concept. The fundamental premise of that concept is that technologies and procedures need to be developed for flight deck and ground operations to improve the efficiency, the predictability, the flexibility and the safety of airspace management and operations. To that end NASA Ames has undertaken an initial development and exploration of "key concepts" in the free flight airspace management technology development. Human Factors issues in automation aiding design, coupled aiding systems between air and ground, communication protocols in distributed decision making, and analytic techniques for definition of concepts of airspace density and operator cognitive load have been undertaken. This paper reports the progress of these efforts, which are not intended to definitively solve the many evolving issues of design for future ATM systems, but to provide preliminary results to chart the parameters of performance and the topology of the analytic effort required. The preliminary research in provision of cockpit display of traffic information, dynamic density definition, distributed decision making, situation awareness models and human performance models is discussed as they focus on the theme of "design requirements".

  5. Research Initiatives and Preliminary Results In Automation Design In Airspace Management in Free Flight

    Science.gov (United States)

    Corker, Kevin; Lebacqz, J. Victor (Technical Monitor)

    1997-01-01

    The NASA and the FAA have entered into a joint venture to explore, define, design and implement a new airspace management operating concept. The fundamental premise of that concept is that technologies and procedures need to be developed for flight deck and ground operations to improve the efficiency, the predictability, the flexibility and the safety of airspace management and operations. To that end NASA Ames has undertaken an initial development and exploration of "key concepts" in the free flight airspace management technology development. Human Factors issues in automation aiding design, coupled aiding systems between air and ground, communication protocols in distributed decision making, and analytic techniques for definition of concepts of airspace density and operator cognitive load have been undertaken. This paper reports the progress of these efforts, which are not intended to definitively solve the many evolving issues of design for future ATM systems, but to provide preliminary results to chart the parameters of performance and the topology of the analytic effort required. The preliminary research in provision of cockpit display of traffic information, dynamic density definition, distributed decision making, situation awareness models and human performance models is discussed as they focus on the theme of "design requirements".

  6. The Revival of Memory: Gardens and Avenues of Remembrance. Early Results of a Research in Abruzzo

    Directory of Open Access Journals (Sweden)

    Aldo Giorgio Pezzi

    2014-06-01

    Full Text Available The forthcoming centenary of the Great War (1914-1918 can be considered an important occasion to focus attention on the subject of memorials for the fallen in the War. Immediately after the War, this topic was considered so relevant that in each municipality of Italy, Gardens and Avenues of Remembrance were realized and soon became places of memory, characterized by strong values of identity, history and landscape. In these places, usually correspondent to the number of fallen in that neighbourhood and located in urban or peripheral areas, nature and anthropic elements coexisted. For their importance, from 1926 these places have been included among the National Monuments. After the Second World War, avenues and gardens, as well as toponyms, were gradually forgotten and, in many cases, radically transformed. Due to a form of damnatio memoriae, which locations considered symbols of past governments have had to pay, these places have been changed, radically transforming also their authentic significance. A century on, it is important to start a programme for protection and enhancement of this historic heritage (classification at a regional and national scale, measurements, archival research, definition of guide lines for conservation. The essay also describes the early results of the classification of Gardens and Avenues of Remembrance in Abruzzo.

  7. What makes age diverse teams effective? Results from a six-year research program.

    Science.gov (United States)

    Wegge, J; Jungmann, F; Liebermann, S; Shemla, M; Ries, B C; Diestel, S; Schmidt, K-H

    2012-01-01

    Based on a new model of productivity in age diverse tams, findings from a six-year research program are reported in which data from more than 745 natural teams with 8,848 employees in three different fields (car production, administrative work, financial services) were collected. Moreover, central assumptions of this model were tested with a representative survey of the German workforce (N = 2,000). Results support both significant advantages and disadvantages for age-mixed teams. Based on the findings, the following preconditions for the effectiveness of age diverse teams are identified: high task complexity, low salience and high appreciation of age diversity, a positive team climate, low age-discrimination, ergonomic design of work places, and the use of age differentiated leadership. Based on these insights, we developed a new training for supervisors, which addresses the aforementioned aspects and seeks to improve team performance and health of team members. It was found that the training reduces age stereotypes, team conflicts and enhances innovation. Thus, we can conclude that effective interventions for a successful integration of elderly employees in work groups are available and that combinations of measures that address ergonomic design issues, team composition and leadership are to be strongly recommended for practice.

  8. Introductory Paper: Scientific Results on the Turin Shroud Coming from a Paduan University Research Project

    Directory of Open Access Journals (Sweden)

    Fanti Giulio

    2015-01-01

    Full Text Available Turin Shroud (TS is a linen cloth 4.4 m long and 1.1 m wide which shows two, front and back images of a man scourged, crowned with thorns and crucified, who died on a cross and was stabbed in the side with a lance after his death. The Catholic Christian tradition identifies this Man as Jesus Christ resurrected after dead, but not all are unanimous in this identification, partly because science has not been able to give definitive answers. To try to improve a bit the inconclusive answers to which the Science is arrived, a Research Project entitled: “Multidisciplinary analysis applied to the Turin Shroud: study of the body image, of possible ambient pollution and of micro-particles capable to characterize the linen fabric.” has been assigned by the University of Padua (Italy to the Author, who performed various studies on this theme in collaboration with other experts, also of other Italian Universities. In reference to the body image, that is not explainable by Science nor reproducible up to now, experimental tests based on Corona Discharge, produced by intense electric fields, have shown that it is possible to reproduce many of these very peculiar image features. Regarding the TS dating, after the demonstration that the 1988 radiocarbon result is not statistically reliable, probably because of environmental pollution, alternative dating methods based on chemical and mechanical tests showed that its age is compatible with the period in which Jesus Christ lived in Palestine.

  9. Opinions of senior schoolchildren on drugs in the internet: results of a pilot research

    Directory of Open Access Journals (Sweden)

    Anna A. Glukhova

    2017-03-01

    Full Text Available Objective to identify the level of engagement of schoolchildren in the process of distribution of narcotic drugs psychotropic substances or their analogues via information and telecommunication networks of common use. Methods the dialectical approach to cognition of social phenomena allowing to analyze them in historical development and functioning in the context of the totality of objective and subjective factors that determined the choice of the following research methods systematicstructural comparativelegal sociological. Results the analysis was made of the involvement of schoolchildren in the process of distribution of narcotic drugs psychotropic substances or their analogues through informationtelecommunication network on the territory of the Russian Federation by the example of Nizhny Novgorod region. The study revealed the existence of two groups of students a group with psychological protection against harmful habits and a risk group. Each group has its own characteristics depending on sex age relationship to the use of narcotic drugs and psychotropic substances social contacts of students frequency of using the informationtelecommunication networks of common use. Scientific novelty for the first time on the basis of data obtained as a result of the sociolegal studies the situation was reviewed concerning the distribution of narcotic drugs psychotropic substances or their analogues via information and telecommunication networks of common use among secondary schools students. The social characteristics of a group with psychological protection against harmful habits and a risk group were identified. The proposal was made aimed at reducing the level of engagement of schoolchildren in the process of distribution of narcotic drugs psychotropic substances or their analogues. Practical significance the main provisions and conclusions of the article can be used in scientific and teaching activities in addressing issues related to combating

  10. Research results of application of reflexo-therapy in correction of myopia

    Directory of Open Access Journals (Sweden)

    Agasarov L.G.

    2011-09-01

    Full Text Available Objective: To develop the optimum scheme of acupuncture, aimed at improving the functional status of the visual analyzer in patients with myopia. Materials. Treatment was conducted in the main group by reflexology courses in 10 procedures and basic therapy in the control group, only basic therapy. The examination included the classic ophthal-mologic research methods, ultrasound and Doppler echoofthalmografy with color mapping of blood vessels — the ophthalmic artery (OA, central retinal artery (CRA and posterior long ciliary arteries (ZDTSA, the study of visual efficiency and visual assessment of the subjective expression of asthenopia. The results of these studies were subjected to statistical analysis using the method of variation statistics with the computation of the arithmetic mean (M, the average error of the arithmetic mean (m and the level of significance (p. Differences between mean values were considered significant if the probability of errors on the distribution of Student»s less than 0,05. The result showed a pronounced effect method of acupuncture on the clinical features, hemodynamic and ergonomic eye, the severity of visual fatigue and general condition of patients. Conclusion. The use of corporal-auricular acupuncture technique in patients with myopia allowed to increase the visual acuity without correction in 1,6 times, visual acuity with correction in 1,2 times, lower rates of subjective and objective refraction in an average of 29.8 and 32.4%, increase rates of accommodation of more than 1,5 times, to increase blood flow velocity characteristics in the GA by an average of 9.7, the CAC at 33.4 and ZDTSA by 27,5%. All this is possible to reduce the severity of subjective indicators of asthenopia in 58% of cases and to increase visual efficiency by 11,3%

  11. Ferrocene-Boronic Acid-Fructose Binding Based on Dual-Plate Generator-Collector Voltammetry and Square-Wave Voltammetry.

    Science.gov (United States)

    Li, Meng; Xu, Su-Ying; Gross, Andrew J; Hammond, Jules L; Estrela, Pedro; Weber, James; Lacina, Karel; James, Tony D; Marken, Frank

    2015-06-10

    The interaction of ferrocene-boronic acid with fructose is investigated in aqueous 0.1 m phosphate buffer at pH 7, 8 and 9. Two voltammetric methods, based on 1) a dual-plate generator-collector micro-trench electrode (steady state) and 2) a square-wave voltammetry (transient) method, are applied and compared in terms of mechanistic resolution. A combination of experimental data is employed to obtain new insights into the binding rates and the cumulative binding constants for both the reduced ferrocene-boronic acid (pH dependent and weakly binding) and for the oxidised ferrocene-boronic acid (pH independent and strongly binding).

  12. Building pathology in the Netherlands – main problems and results through research and practice.

    NARCIS (Netherlands)

    Thomsen, A.F.

    2014-01-01

    This report is dedicated to the main problems of building pathologies in the Netherlands and the main solutions through research and practice as questioned by the CIB W086 Building Pathology Commission for its 2014 meeting in Sao Paulo, Brazil. Objective is to contribute to the Research Roadmap 2014

  13. An Engineering Research Program for High School Science Teachers: Year Two Changes and Results

    Science.gov (United States)

    DeJong, Brian P.; Yelamarthi, Kumar; Kaya, Tolga

    2016-01-01

    The research experiences for teachers program at Central Michigan University was initiated to team in-service and pre-service teachers with undergraduate engineering students and engineering faculty, in an engineering research setting. During the six-week program, teachers learn engineering concepts and develop high-school instructional material…

  14. Major Results and Research Challenges in Cotton Molecular Genetics at CIRAD(France)

    Institute of Scientific and Technical Information of China (English)

    LACAPE; Jean-marc; CLAVERIE; M; DESSAUW; D; GIBAND; M; VIOT; C

    2008-01-01

    CIRAD(Montpellier,France) develops research activities centered on tropical and sub-tropical agricultural systems.Among others crops,cotton is the focus of a series of research programs in different disciplines from economics to breeding.Major areas in genetics and breeding relate to(1) genetic diversity,(2) cultivar development through classical and molecular breeding,and(3) applied

  15. Interview-based Qualitative Research in Emergency Care Part II: Data Collection, Analysis and Results Reporting.

    Science.gov (United States)

    Ranney, Megan L; Meisel, Zachary F; Choo, Esther K; Garro, Aris C; Sasson, Comilla; Morrow Guthrie, Kate

    2015-09-01

    Qualitative methods are increasingly being used in emergency care research. Rigorous qualitative methods can play a critical role in advancing the emergency care research agenda by allowing investigators to generate hypotheses, gain an in-depth understanding of health problems or specific populations, create expert consensus, and develop new intervention and dissemination strategies. In Part I of this two-article series, we provided an introduction to general principles of applied qualitative health research and examples of its common use in emergency care research, describing study designs and data collection methods most relevant to our field (observation, individual interviews, and focus groups). Here in Part II of this series, we outline the specific steps necessary to conduct a valid and reliable qualitative research project, with a focus on interview-based studies. These elements include building the research team, preparing data collection guides, defining and obtaining an adequate sample, collecting and organizing qualitative data, and coding and analyzing the data. We also discuss potential ethical considerations unique to qualitative research as it relates to emergency care research.

  16. Towards a European research agenda for CIIP: Results from the CI ² RCO project

    NARCIS (Netherlands)

    Bendisch, U.; Bologna, S.; Le Grand, G.; Luiijf, H.A.M.

    2008-01-01

    This paper discusses the European Research Agenda for Critical In formation Infrastructure Protection (CIIP) which has been developed by the EU IST CI 2RCO project. The Agenda identifies research challenges and analyses existing R&D gaps in CIIP. It integrates the insights and ideas of a

  17. A Phenomenological Research Study on Writer's Block: Causes, Processes, and Results

    Science.gov (United States)

    Bastug, Muhammet; Ertem, Ihsan Seyit; Keskin, Hasan Kagan

    2017-01-01

    Purpose: The purpose of this paper is to investigate the causes, processes of writer's block experienced by a group of classroom teacher candidates and its impact on them. Design/methodology/approach: The phenomenological design, which is a qualitative research design, was preferred in the research since it was aimed to investigate the causes,…

  18. Interview-Based Qualitative Research in Emergency Care Part II: Data Collection, Analysis and Results Reporting

    Science.gov (United States)

    Ranney, Megan L.; Meisel, Zachary; Choo, Esther K.; Garro, Aris; Sasson, Comilla; Morrow, Kathleen

    2015-01-01

    Qualitative methods are increasingly being used in emergency care research. Rigorous qualitative methods can play a critical role in advancing the emergency care research agenda by allowing investigators to generate hypotheses, gain an in-depth understanding of health problems or specific populations, create expert consensus, and develop new intervention and dissemination strategies. In Part I of this two-article series, we provided an introduction to general principles of applied qualitative health research and examples of its common use in emergency care research, describing study designs and data collection methods most relevant to our field (observation, individual interviews, and focus groups). Here in Part II of this series, we outline the specific steps necessary to conduct a valid and reliable qualitative research project, with a focus on interview-based studies. These elements include building the research team, preparing data collection guides, defining and obtaining an adequate sample, collecting and organizing qualitative data, and coding and analyzing the data. We also discuss potential ethical considerations unique to qualitative research as it relates to emergency care research. PMID:26284572

  19. The E-Business Research Network: summary of the results of the Dutch pilot survey

    NARCIS (Netherlands)

    A. van der Wiele (Ton); A.R.T. Williams (Roger); J.D. van Iwaarden (Jos); M. Wilson (Melanie); B.G. Dale (Barry)

    2001-01-01

    textabstractA project has been started with the intention to develop an E-Business Research Network on E-business related research in business and management. The initiative has been taken in co-operation between Erasmus University and UMIST to develop a project in which the first stage concerns the

  20. [Medical and biologic research of electromagnetic fields in radiofrequencies range. Results and prospects].

    Science.gov (United States)

    Kaliada, T V; Vishnevskiĭ, A M; Gorodetskiĭ, B N; Plekhanov, V P; Kuznetsov, A V

    2014-01-01

    The authors present research findings on the problem of technology-related electromagnetic fields as an occupational risk factor of workers health disturbances, and on the issue of prevention measures development against this adverse physical factor effects. Prospects for further research development in the field of electromagnetic safety are discussed.