Science.gov

Sample records for addressed electrochemical experiments

  1. Individually addressable vertically aligned carbon nanofiber-based electrochemical probes

    NASA Astrophysics Data System (ADS)

    Guillorn, M. A.; McKnight, T. E.; Melechko, A.; Merkulov, V. I.; Britt, P. F.; Austin, D. W.; Lowndes, D. H.; Simpson, M. L.

    2002-03-01

    In this paper we present the fabrication and initial testing results of high aspect ratio vertically aligned carbon nanofiber (VACNF)-based electrochemical probes. Electron beam lithography was used to define the catalytic growth sites of the VACNFs. Following catalyst deposition, VACNF were grown using a plasma enhanced chemical vapor deposition process. Photolithography was performed to realize interconnect structures. These probes were passivated with a thin layer of SiO2, which was then removed from the tips of the VACNF, rendering them electrochemically active. We have investigated the functionality of completed devices using cyclic voltammetry (CV) of ruthenium hexammine trichloride, a highly reversible, outer sphere redox system. The faradaic current obtained during CV potential sweeps shows clear oxidation and reduction peaks at magnitudes that correspond well with the geometry of these nanoscale electrochemical probes. Due to the size and the site-specific directed synthesis of the VACNFs, these probes are ideally suited for characterizing electrochemical phenomena with an unprecedented degree of spatial resolution.

  2. Laboratory Experiments on the Electrochemical Remediation of the Environment

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; Tellez-Giron, Monica; Alvarez, Diana

    2004-01-01

    Ferrate, which is a strong iron oxidant for removing pollutants from water, is developed electrochemically in the laboratory, and used for experiments simulating environmental situations. Thus, ferrate is a powerful oxidizing agent capable of destroying an immense variety of contaminants.

  3. The 2009 Kurt Hahn Address: Seeking Deeper Understandings from Experiences

    ERIC Educational Resources Information Center

    Knapp, Clifford E.

    2010-01-01

    This address used a narrative style to convey several stories drawn from the speaker's life. These stories illustrated various points about the value of experience for expanding learners' deep understandings of the content through the use of know-how knowledge. Know-how knowledge was contrasted with know-that knowledge in order to demonstrate the…

  4. Direct Electrochemical Addressing of Immobilized Alcohol Dehydrogenase for the Heterogeneous Bioelectrocatalytic Reduction of Butyraldehyde to Butanol

    PubMed Central

    Schlager, S; Neugebauer, H; Haberbauer, M; Hinterberger, G; Sariciftci, N S

    2015-01-01

    Modified electrodes using immobilized alcohol dehydrogenase enzymes for the efficient electroreduction of butyraldehyde to butanol are presented as an important step for the utilization of CO2-reduction products. Alcohol dehydrogenase was immobilized, embedded in an alginate–silicate hybrid gel, on a carbon felt (CF) electrode. The application of this enzyme to the reduction of an aldehyde to an alcohol with the aid of the coenzyme nicotinamide adenine dinucleotide (NADH), in analogy to the final step in the natural reduction cascade of CO2 to alcohol, has been already reported. However, the use of such enzymatic reductions is limited because of the necessity of providing expensive NADH as a sacrificial electron and proton donor. Immobilization of such dehydrogenase enzymes on electrodes and direct pumping of electrons into the biocatalysts offers an easy and efficient way for the biochemical recycling of CO2 to valuable chemicals or alternative synthetic fuels. We report the direct electrochemical addressing of immobilized alcohol dehydrogenase for the reduction of butyraldehyde to butanol without consumption of NADH. The selective reduction of butyraldehyde to butanol occurs at room temperature, ambient pressure and neutral pH. Production of butanol was detected by using liquid-injection gas chromatography and was estimated to occur with Faradaic efficiencies of around 40 %. PMID:26113881

  5. Best Practices for Operando Battery Experiments: Influences of X-ray Experiment Design on Observed Electrochemical Reactivity

    SciTech Connect

    Borkiewicz, O. J.; Wiaderek, Kamila M.; Chupas, Peter J.; Chapman, Karena W.

    2015-06-04

    Dynamic properties and multiscale complexities governing electrochemical energy storage in batteries are most ideally interrogated under simulated operating conditions within an electrochemical cell. We assess how electrochemical reactivity can be impacted by experiment design, including the X-ray measurements or by common features or adaptations of electrochemical cells that enable X-ray measurements.

  6. Addressing Earth Science Data Access Challenges through User Experience Research

    NASA Astrophysics Data System (ADS)

    Hemmings, S. N.; Banks, B.; Kendall, J.; Lee, C. M.; Irwin, D.; Toll, D. L.; Searby, N. D.

    2013-12-01

    The NASA Capacity Building Program (Earth Science Division, Applied Sciences Program) works to enhance end-user capabilities to employ Earth observation and Earth science (EO/ES) data in decision-making. Open data access and user-tailored data delivery strategies are critical elements towards this end. User Experience (UX) and User Interface (UI) research methods can offer important contributions towards addressing data access challenges, particularly at the interface of science application/product development and product transition to end-users. This presentation focuses on developing nation contexts and describes methods, results, and lessons learned from two recent UX/UI efforts conducted in collaboration with NASA: the SERVIRglobal.net redesign project and the U.S. Water Partnership (USWP) Portal development effort. SERVIR, a collaborative venture among NASA, USAID, and global partners, seeks to improve environmental management and climate change response by helping governments and other stakeholders integrate EO and geospatial technologies into decision-making. The USWP, a collaboration among U.S. public and private sectors, harnesses U.S.-based resources and expertise to address water challenges in developing nations. SERVIR's study, conducted from 2010-2012, assessed and tested user needs, preferences, and online experiences to generate a more user-friendly online data portal at SERVIRglobal.net. The portal provides a central access interface to data and products from SERVIR's network of hubs in East Africa, the Hindu Kush Himalayas, and Mesoamerica. The second study, conducted by the USWP Secretariat and funded by the U.S. Department of State, seeks to match U.S.-based water information resources with developing nation stakeholder needs. The USWP study utilizes a multi-pronged approach to identify key design requirements and to understand the existing water data portal landscape. Adopting UX methods allows data distributors to design customized UIs that

  7. Artificial solid electrolyte interphase to address the electrochemical degradation of silicon electrodes.

    PubMed

    Li, Juchuan; Dudney, Nancy J; Nanda, Jagjit; Liang, Chengdu

    2014-07-09

    Electrochemical degradation on silicon (Si) anodes prevents them from being successfully used in lithium (Li)-ion battery full cells. Unlike the case of graphite anodes, the natural solid electrolyte interphase (SEI) films generated from carbonate electrolytes do not self-passivate on Si, causing continuous electrolyte decomposition and loss of Li ions. In this work, we aim at solving the issue of electrochemical degradation by fabricating artificial SEI films using a solid electrolyte material, lithium phosphorus oxynitride (Lipon), which conducts Li ions and blocks electrons. For Si anodes coated with Lipon of 50 nm or thicker, a significant effect is observed in suppressing electrolyte decomposition, while Lipon of thinner than 40 nm has a limited effect. Ionic and electronic conductivity measurements reveal that the artificial SEI is effective when it is a pure ionic conductor, but electrolyte decomposition is only partially suppressed when the artificial SEI is a mixed electronic-ionic conductor. The critical thickness for this transition in conducting behavior is found to be 40-50 nm. This work provides guidance for designing artificial SEI films for high-capacity Li-ion battery electrodes using solid electrolyte materials.

  8. Label-free electrochemical monitoring of protein addressing through electroactivated "click" chemistry on gold electrodes.

    PubMed

    Meini, Nadir; Ripert, Micaël; Chaix, Carole; Farre, Carole; De Crozals, Gabriel; Kherrat, Rochdi; Jaffrezic-Renault, Nicole

    2014-05-01

    In this work, using electrochemical impedance spectroscopy (EIS), we have, for the first time, label-free monitored protein immobilization on a gold surface through a strategy of electroaddressing, compatible with the production of microarrays for multi-detection. This functionalization is achieved via the alkyne/azide cycloaddition, better known as the "click" reaction. The electroaddressing was applied to a polythiol hexynyl derivative previously grafted onto the gold surface. This compound consists of two dithiol phosphate groups and a hexynyl function and was synthesized through a supported synthesis approach, from a dithiol reagent, phosphoramidite (DTPA), and a hexynyl phosphoramidite. Next, an azide-PEG3-biotin derivative was grafted onto the modified gold surface by electro-chronocoulometry. The "click" reaction was controlled by electrochemical impedance spectroscopy, showing the change in impedance only when the electroaddressing was performed at -300 mV. No effect on the EIS signal was observed when a positive potential was applied, confirming the specificity of the electroactivation. Biotin-modified electrodes were used to fix streptavidin and the immobilization was monitored using EIS. Fluorescent streptavidin-functionalized silica nanoparticles were also specifically grafted onto the biotinylated gold surface in order to confirm the "click" reaction using fluorescence microscopy. The obtained streptavidin platform was used to detect the surface coverage by biotinylated human serum albumin (HSA). The lowest detectable concentration is 10 pg/mL, and surface saturation is obtained with concentrations higher than 100 ng/mL.

  9. Artificial Solid Electrolyte Interphase to Address the Electrochemical Degradation of Silicon Electrodes

    SciTech Connect

    Dudney, Nancy J; Nanda, Jagjit; Liang, Chengdu; Li, Juchuan

    2014-01-01

    Electrochemical degradation on Si anodes prevents them from being successfully used in lithium-ion full cells. Unlike the case of graphite anodes, natural solid electrolyte interphase (SEI) films generated from carbonate electrolyte do not self-passivate on Si and causes continuous electrolyte decomposition. In this work we aim at solving the issue of electrochemical degradation by fabricating artificial SEI films using a solid electrolyte material, lithium phosphor oxynitride (Lipon), that conducts Li ions and blocks electrons. For Si anodes coated with Lipon of 50 nm or thicker, significant effect is observed in suppressing the electrolyte decomposition, while Lipon of thinner than 40 nm has little effect. Ionic and electronic conductivity measurement reveals that the artificial SEI is effective when it is a pure ionic conductor, and the electrolyte decomposition is not suppressed when the artificial SEI is a mixed electronic-ionic conductor. The critical thickness for this transition in conducting behavior is found to be 40~50 nm. This work provides guidance for designing artificial SEI for high capacity lithium-ion battery electrodes using solid electrolyte materials.

  10. Double remote electrochemical addressing and optical readout of electrochemiluminescence at the tip of an optical fiber.

    PubMed

    Li, Haidong; Garrigue, Patrick; Bouffier, Laurent; Arbault, Stéphane; Kuhn, Alexander; Sojic, Neso

    2016-07-21

    In this work, we report an original strategy for the wireless electrochemical generation of light at the tip of an optical fiber bundle, coupled with a simultaneous remote readout. An optical fiber bundle coated with a nanometer-thin gold film acts as a dual platform, on the one hand to locally generate electrochemiluminescence (ECL) in a wireless manner by bipolar electrochemistry, and on the other hand to guide the resulting ECL signal. The light emission is triggered and collected at one end, transmitted by the waveguide and remotely detected at the opposite end. Integration of both functionalities at the level of the same miniaturized object leads to an unprecedented bipolar opto-electrode, allowing one to quantify the ECL intensity as a function of different parameters in a double remote approach with interesting potential applications, ranging from high-throughput catalyst screening to massive parallel biochemical analysis.

  11. Electrochemically addressable trisradical rotaxanes organized within a metal–organic framework

    PubMed Central

    McGonigal, Paul R.; Deria, Pravas; Hod, Idan; Moghadam, Peyman Z.; Avestro, Alyssa-Jennifer; Horwitz, Noah E.; Gibbs-Hall, Ian C.; Blackburn, Anthea K.; Chen, Dongyang; Botros, Youssry Y.; Wasielewski, Michael R.; Snurr, Randall Q.; Hupp, Joseph T.; Farha, Omar K.; Stoddart, J. Fraser

    2015-01-01

    The organization of trisradical rotaxanes within the channels of a Zr6-based metal–organic framework (NU-1000) has been achieved postsynthetically by solvent-assisted ligand incorporation. Robust ZrIV–carboxylate bonds are forged between the Zr clusters of NU-1000 and carboxylic acid groups of rotaxane precursors (semirotaxanes) as part of this building block replacement strategy. Ultraviolet–visible–near-infrared (UV-Vis-NIR), electron paramagnetic resonance (EPR), and 1H nuclear magnetic resonance (NMR) spectroscopies all confirm the capture of redox-active rotaxanes within the mesoscale hexagonal channels of NU-1000. Cyclic voltammetry measurements performed on electroactive thin films of the resulting material indicate that redox-active viologen subunits located on the rotaxane components can be accessed electrochemically in the solid state. In contradistinction to previous methods, this strategy for the incorporation of mechanically interlocked molecules within porous materials circumvents the need for de novo synthesis of a metal–organic framework, making it a particularly convenient approach for the design and creation of solid-state molecular switches and machines. The results presented here provide proof-of-concept for the application of postsynthetic transformations in the integration of dynamic molecular machines with robust porous frameworks. PMID:26283386

  12. Addressing Energy Demand through Demand Response. International Experiences and Practices

    SciTech Connect

    Shen, Bo; Ghatikar, Girish; Ni, Chun Chun; Dudley, Junqiao; Martin, Phil; Wikler, Greg

    2012-06-01

    Demand response (DR) is a load management tool which provides a cost-effective alternative to traditional supply-side solutions to address the growing demand during times of peak electrical load. According to the US Department of Energy (DOE), demand response reflects “changes in electric usage by end-use customers from their normal consumption patterns in response to changes in the price of electricity over time, or to incentive payments designed to induce lower electricity use at times of high wholesale market prices or when system reliability is jeopardized.” 1 The California Energy Commission (CEC) defines DR as “a reduction in customers’ electricity consumption over a given time interval relative to what would otherwise occur in response to a price signal, other financial incentives, or a reliability signal.” 2 This latter definition is perhaps most reflective of how DR is understood and implemented today in countries such as the US, Canada, and Australia where DR is primarily a dispatchable resource responding to signals from utilities, grid operators, and/or load aggregators (or DR providers).

  13. Demonstration of Electrochemical Cell Properties by a Simple, Colorful Oxidation-reduction Experiment.

    ERIC Educational Resources Information Center

    Hendricks, Lloyd J.; And Others

    1982-01-01

    Describes apparatus/methodology and provides background information for an experiment demonstrating electrochemical concepts and properties of electrochemical cells. The color of a solution close to an electrode is changed from that of the bulk solution to either of two contrasting colors depending on whether the reaction is oxidation or…

  14. Identifying and Addressing Student Difficulties with the Millikan Oil Drop Experiment

    ERIC Educational Resources Information Center

    Klassen, Stephen

    2009-01-01

    The Millikan oil drop experiment has been characterized as one of the "most beautiful" physics experiments of all time and, certainly, as one of the most frustrating of all the exercises in the undergraduate physics laboratory. A literature review reveals that work done on addressing student difficulties in performing the oil drop experiment has,…

  15. Native Language Experience Shapes Neural Basis of Addressed and Assembled Phonologies

    PubMed Central

    Mei, Leilei; Xue, Gui; Lu, Zhong-Lin; He, Qinghua; Wei, Miao; Zhang, Mingxia; Dong, Qi; Chen, Chuansheng

    2015-01-01

    Previous studies have suggested differential engagement of addressed and assembled phonologies in reading Chinese and alphabetic languages (e.g., English) and the modulatory role of native language in learning to read a second language. However, it is not clear whether native language experience shapes the neural mechanisms of addressed and assembled phonologies. To address this question, we trained native Chinese and native English speakers to read the same artificial language (based on Korean Hangul) either through addressed (i.e., whole-word mapping) or assembled (i.e., grapheme-to-phoneme mapping) phonology. We found that, for both native Chinese and native English speakers, addressed phonology relied on the regions in the ventral pathway, whereas assembled phonology depended on the regions in the dorsal pathway. More importantly, we found that the neural mechanisms of addressed and assembled phonologies were shaped by native language experience. Specifically, two key regions for addressed phonology (i.e., the left middle temporal gyrus and right inferior temporal gyrus) showed greater activation for addressed phonology in native Chinese speakers, while one key region for assembled phonology (i.e., the left supramarginal gyrus) showed more activation for assembled phonology in native English speakers. These results provide direct neuroimaging evidence for the effect of native language experience on the neural mechanisms of phonological access in a new language and support the assimilation-accommodation hypothesis. PMID:25858447

  16. Native language experience shapes neural basis of addressed and assembled phonologies.

    PubMed

    Mei, Leilei; Xue, Gui; Lu, Zhong-Lin; He, Qinghua; Wei, Miao; Zhang, Mingxia; Dong, Qi; Chen, Chuansheng

    2015-07-01

    Previous studies have suggested differential engagement of addressed and assembled phonologies in reading Chinese and alphabetic languages (e.g., English) and the modulatory role of native language in learning to read a second language. However, it is not clear whether native language experience shapes the neural mechanisms of addressed and assembled phonologies. To address this question, we trained native Chinese and native English speakers to read the same artificial language (based on Korean Hangul) either through addressed (i.e., whole-word mapping) or assembled (i.e., grapheme-to-phoneme mapping) phonology. We found that, for both native Chinese and native English speakers, addressed phonology relied on the regions in the ventral pathway, whereas assembled phonology depended on the regions in the dorsal pathway. More importantly, we found that the neural mechanisms of addressed and assembled phonologies were shaped by native language experience. Specifically, one key region for addressed phonology (i.e., the left middle temporal gyrus) showed greater activation for addressed phonology in native Chinese speakers, while one key region for assembled phonology (i.e., the left supramarginal gyrus) showed more activation for assembled phonology in native English speakers. These results provide direct neuroimaging evidence for the effect of native language experience on the neural mechanisms of phonological access in a new language and support the assimilation-accommodation hypothesis.

  17. 2011 AERA Presidential Address: Designing Resilient Ecologies--Social Design Experiments and a New Social Imagination

    ERIC Educational Resources Information Center

    Gutiérrez, Kris D.

    2016-01-01

    This article is about designing for educational possibilities--designs that in their inception, social organization, and implementation squarely address issues of cultural diversity, social inequality, and robust learning. I discuss an approach to design-based research, social design experiments, that privileges a social scientific inquiry…

  18. Identifying and Addressing Student Difficulties with the Millikan Oil Drop Experiment

    NASA Astrophysics Data System (ADS)

    Klassen, Stephen

    2009-05-01

    The Millikan oil drop experiment has been characterized as one of the ‘most beautiful’ physics experiments of all time and, certainly, as one of the most frustrating of all the exercises in the undergraduate physics laboratory. A literature review reveals that work done on addressing student difficulties in performing the oil drop experiment has, to date, not achieved a significant measure of success. The historical background of the oil drop experiment is well established in the literature from the perspective of historians of science, but not so from the perspective of teachers and students of science. A summary of historical details surrounding the original experiment suitable for use in revising the instructional approach is presented. Both Millikan and his graduate student, Fletcher, are featured with the view to emphasizing details that humanize the protagonists and that are likely to raise student interest. The issue of the necessary reliance on presuppositions in doing speculative research is raised, both from the historical account and from the insights of university physics students who heard the historical account and performed the experiment. Difficulties current students have in performing the experiment are discussed from the perspective of Hodson (Stud Sci Educ 22:85-142, 1993) framework and the students’ own observations. Last, further historical materials are outlined that may be used to encourage student insight into the fundamental nature of electricity. It is proposed that these aspects are essential as a basis for identifying and addressing student difficulties with the Millikan oil drop experiment.

  19. An Electrochemical Experiment Using an Optically Transparent Thin Layer Electrode

    ERIC Educational Resources Information Center

    DeAngelis, Thomas P.; Heineman, William R.

    1976-01-01

    Describes a unified experiment in which an optically transparent thin layer electrode is used to illustrate the techniques of thin layer electrochemistry, cyclic voltammetry, controlled potential coulometry, and spectroelectrochemistry. (MLH)

  20. How Does an Environmental Educator Address Student Engagement in a Meaningful Watershed Educational Experience (MWEE)?

    NASA Astrophysics Data System (ADS)

    Char, Chelia

    Children represent the future and thus by providing them with effective environmental educational experiences, educators may be taking a critical step in preventing "the probable serious environmental problems in the future" (Gokhan, 2010, p. 56). The Meaningful Watershed Educational Experience (MWEE) is an excellent example of one such education program. MWEEs aim to educate and enhance the students' relationship with the Chesapeake Bay Watershed through an integration of classroom activities and fieldwork. As environmental educators and role models, field interpreters are a major component and significant influence on the local MWEE programs, however their perspective as to how they have impacted the programs has yet to be examined. Through a qualitative analysis and specific focus on the behavioral, emotional, and cognitive dimensions of student engagement, the researcher intended to address this void. The focus of the study was to examine how the local MWEE field interpreters understood and addressed student engagement in a field setting. This was measured via data collected from observations of and semi-structured, one-on-one interviews with each field interpreter involved with the local MWEE programs. Data analysis uncovered that field interpreters demonstrated a strong awareness of student engagement. Furthermore, they defined, recognized, and addressed student engagement within the constructs of the emotional, behavioral, and cognitive dimensions. Ultimately, the individual experiences of each MWEE field interpreter provides insight into the phenomenon, however further research is required to strengthen the awareness of how, if at all, their perspectives of student engagement directly impact student outcomes.

  1. CO oxidation on stepped-Pt(111) under electrochemical conditions: insights from theory and experiment.

    PubMed

    Busó-Rogero, C; Herrero, E; Bandlow, J; Comas-Vives, A; Jacob, Timo

    2013-11-14

    The co-adsorption of CO and OH on two Pt stepped surfaces vicinal to the (111) orientation has been evaluated by means of density functional theory (DFT) calculations. Focusing on Pt(533) and Pt(221), which contain (100) and (111)-steps, respectively, we find that (111)-steps should be more reactive towards CO oxidation than surfaces containing (100)-steps. The DFT results are compared with electrochemical experiments on the CO adsorption and oxidation on these vicinal surfaces.

  2. Addressing Student Success and Retention in STEM Majors Through Strategic Curriculum Pathways and Early Research Experiences

    NASA Astrophysics Data System (ADS)

    Jaspersohn, Robert P.

    In this dissertation we discuss a common first-year STEM curriculum pathway for undergraduate students majoring in science, math, or engineering, and a modification to this curriculum pathway that has been implemented, based on students' needs prior to enrollment. The intent is increasing student retention and success in the university and in STEM. The effects of the modification on student success, progression, retention and persistence are assessed, specifically. Second year retention in the university for the students who went through the modification has increased by 5%. Alternate non-traditional pathways within the first year physics laboratory experience can be introduced to address student needs.

  3. The Mexican experience in monitoring and evaluation of public policies addressing social determinants of health

    PubMed Central

    Valle, Adolfo Martinez

    2016-01-01

    Monitoring and evaluation (M&E) have gradually become important and regular components of the policy-making process in Mexico since, and even before, the World Health Organization (WHO) Commission on Social Determinants of Health (CSDH) called for interventions and policies aimed at tackling the social determinants of health (SDH). This paper presents two case studies to show how public policies addressing the SDH have been monitored and evaluated in Mexico using reliable, valid, and complete information, which is not regularly available. Prospera, for example, evaluated programs seeking to improve the living conditions of families in extreme poverty in terms of direct effects on health, nutrition, education and income. Monitoring of Prospera's implementation has also helped policy-makers identify windows of opportunity to improve the design and operation of the program. Seguro Popular has monitored the reduction of health inequalities and inequities evaluated the positive effects of providing financial protection to its target population. Useful and sound evidence of the impact of programs such as Progresa and Seguro Popular plus legal mandates, and a regulatory evaluation agency, the National Council for Social Development Policy Evaluation, have been fundamental to institutionalizing M&E in Mexico. The Mexican experience may provide useful lessons for other countries facing the challenge of institutionalizing the M&E of public policy processes to assess the effects of SDH as recommended by the WHO CSDH. PMID:26928215

  4. The Mexican experience in monitoring and evaluation of public policies addressing social determinants of health.

    PubMed

    Valle, Adolfo Martinez

    2016-01-01

    Monitoring and evaluation (M&E) have gradually become important and regular components of the policy-making process in Mexico since, and even before, the World Health Organization (WHO) Commission on Social Determinants of Health (CSDH) called for interventions and policies aimed at tackling the social determinants of health (SDH). This paper presents two case studies to show how public policies addressing the SDH have been monitored and evaluated in Mexico using reliable, valid, and complete information, which is not regularly available. Prospera, for example, evaluated programs seeking to improve the living conditions of families in extreme poverty in terms of direct effects on health, nutrition, education and income. Monitoring of Prospera's implementation has also helped policy-makers identify windows of opportunity to improve the design and operation of the program. Seguro Popular has monitored the reduction of health inequalities and inequities evaluated the positive effects of providing financial protection to its target population. Useful and sound evidence of the impact of programs such as Progresa and Seguro Popular plus legal mandates, and a regulatory evaluation agency, the National Council for Social Development Policy Evaluation, have been fundamental to institutionalizing M&E in Mexico. The Mexican experience may provide useful lessons for other countries facing the challenge of institutionalizing the M&E of public policy processes to assess the effects of SDH as recommended by the WHO CSDH.

  5. Using electrochemical noise to detect corrosion: Evaluation of a round-robin experiment

    SciTech Connect

    Coellner, J.; Burkhert, A.; Heyn, A. ); Hickling, J. )

    1999-05-01

    Successful measurement of electrochemical noise (EN) signals requires that a number of preconditions be fulfilled. In particular, fundamental understanding of the dynamics of the corrosion system concerned must be combined with an appreciation of the way in which the measurements are made. Broader acceptance of the technique requires a joint effort by the various corrosion investigators and laboratories concerned. This, in turn, requires that a common basis for discussion be established. With this in mind, a round-robin experiment was organized on EN measurements. The participation of 17 organizations (universities, commercial firms, and research and development laboratories) from five countries was obtained. The experiment involved the investigation of EN signals from aluminum and stainless steel (SS) exposed under conditions in which pitting corrosion can occur. Data provided by the participants were analyzed according to various criteria. Evaluation methods included visual inspection of noise in the curves of potential or current vs time, calculation of the standard deviation, counting of transients, and transformation of measurements into the frequency domain. Almost all of the participants were able to detect differences in EN behavior during different stages of the experiment qualitatively. However, quantitative evaluation revealed a more complex situation. At times, differences in measured EN signal intensity of 2 orders of magnitude were obtained as a result of the different apparatus used (sensitivity, frequency range, etc.). Nonetheless, the fact that more than half of the participants reported data within a relatively narrow scatterband was a positive result. The experience gained provided a sound basis for further development of EN as a tool for fundamental understanding of various aspects of corrosion and for the solution of practical problems of corrosion protection, particularly in the area of corrosion monitoring.

  6. ISSUES THAT MUST BE ADDRESSED FOR RISK ASSESSMENT OF MIXED EXPOSURES: THE EPA EXPERIENCE WITH AIR QUALITY

    EPA Science Inventory

    Issues that Must be Addressed for Risk Assessment of Mixed Exposures: The EPA Experience with Air Quality

    Daniel L. Costa, Sc.D.

    Abstract
    Humans are routinely exposed to a complex mixture of air pollutants in both their outdoor and indoor environments. The wide...

  7. R AND D EXPERIMENTS AT BNL TO ADDRESS THE ASSOCIATED ISSUES IN THE CASCADING HGHG SCHEME

    SciTech Connect

    YU,L.-H.

    2004-08-30

    The proof-of-principle HGHG experiment at 5 {mu} [1, 2] and recent HGHG experiment at DUVFEL [3] have generated significant interests in the FEL community. The more relaxed requirement on electron beam current and emittance to generate coherent deep UV output with much narrower bandwidth and high pulse energy stability, as exhibited by the recent experiment, and its potential to be generalized to soft-x-ray FEL, have attracted much attention. Several labs, including BESSY, ELETRRA, LBL, MIT, and SSRF proposed the development of UVFEL based on HGHG principle or soft-x-ray FEL based on the cascaded HGHG principle [4, 5]. Among them SSRF has already started the construction of an FEL system based on the HGHG principle [6]. Hence it would be a contribution to be able to carry out a first proof-of-principle experiment of cascaded HGHG at DUVFEL. In this paper, we discuss this experiment and several associated experiments that can be carried out at BNL before this experiment and may also have important impact on the development of multi-stage cascaded HGHG FELs.

  8. Presidential Address: Social Change and Human Development--Experiences from German Unification

    ERIC Educational Resources Information Center

    Silbereisen, Rainer K.

    2005-01-01

    It is well known that human development is influenced by social change. In particular, as evidenced by research on German unification, the rapid change of social institutions can impact on various aspects of behaviour and development. Based on my own research experience in this field, I want to show the necessity for a better interdisciplinary…

  9. Synchronising Pedagogy and Musical Experiences in Early Childhood: Addressing Challenges in Preschool Music Education in Kenya

    ERIC Educational Resources Information Center

    Andang'o, Elizabeth A.

    2009-01-01

    This paper examines pedagogy in early childhood music education and the resultant learning experiences in music for children in Kenyan preschools. Two important principles proposed for the synchronisation of teaching and learning in early childhood music education are cultural relevance and developmental appropriateness. These terms are…

  10. International experience in addressing combined exposures: increasing the efficiency of assessment.

    PubMed

    Meek, M E Bette

    2013-11-16

    More efficient methodology for assessing the impact of combined exposures to multiple chemicals has been considered in a project of the World Health Organization (WHO) International Programme on Chemical Safety (IPCS). Recommendations regarding terminology and the status of development of the framework, its content, review and application are described. Evolving experience in its application is illustrated by example (polybrominated diphenyls) with special emphasis on the critical content of problem formulation, the role of predictive tools in grouping of chemicals for consideration and the importance of explicit delineation of relative uncertainty and sensitivity for tiered assessment. Priorities in increasing the efficiency of risk assessment not only for combined exposures, but more generally based on experience acquired in developing the framework and its application in case studies are identified and recommendations included.

  11. Research to action to address inequities: the experience of the Cape Town Equity Gauge

    PubMed Central

    Scott, Vera; Stern, Ruth; Sanders, David; Reagon, Gavin; Mathews, Verona

    2008-01-01

    Background While the importance of promoting equity to achieve health is now recognised, the health gap continues to increase globally between and within countries. The description that follows looks at how the Cape Town Equity Gauge initiative, part of the Global Equity Gauge Alliance (GEGA) is endeavouring to tackle this problem. We give an overview of the first phase of our research in which we did an initial assessment of health status and the socio-economic determinants of health across the subdistrict health structures of Cape Town. We then describe two projects from the second phase of our research in which we move from research to action. The first project, the Equity Tools for Managers Project, engages with health managers to develop two tools to address inequity: an Equity Measurement Tool which quantifies inequity in health service provision in financial terms, and a Equity Resource Allocation Tool which advocates for and guides action to rectify inequity in health service provision. The second project, the Water and Sanitation Project, engages with community structures and other sectors to address the problem of diarrhoea in one of the poorest areas in Cape Town through the establishment of a community forum and a pilot study into the acceptability of dry sanitation toilets. Methods A participatory approach was adopted. Both quantitative and qualitative methods were used. The first phase, the collection of measurements across the health subdistricts of Cape Town, used quantitative secondary data to demonstrate the inequities. In the Equity Tools for Managers Project further quantitative work was done, supplemented by qualitative policy analysis to study the constraints to implementing equity. The Water and Sanitation Project was primarily qualitative, using in-depth interviews and focus group discussions. These were used to gain an understanding of the impact of the inequities, in this instance, inadequate sanitation provision. Results The studies both

  12. Addressing barriers to health: Experiences of breastfeeding mothers after returning to work.

    PubMed

    Valizadeh, Sousan; Hosseinzadeh, Mina; Mohammadi, Eesa; Hassankhani, Hadi; M Fooladi, Marjaneh; Schmied, Virginia

    2017-03-01

    Breastfeeding mothers returning to work often feel exhausted as they must feed on demand and attend to family and employment responsibilities, leading to concerns for their personal health. This study was prompted by a desire to understand and identify barriers to mothers' health. We describe the experiences of 12 Iranian breastfeeding and employed mothers through in-depth and semi-structured interviews and thematic analysis. Two main themes emerged: (i) working and mothering alone and (ii) facing concerns about health. The findings highlight the need for a support system for breastfeeding mothers within the family and in the workplace. Family-friendly policies targeting mothers' and employers' views are needed to support working mothers and promote breastfeeding.

  13. Addressing the socioeconomic determinants of adolescent health: experiences from the WHO/HBSC Forum 2007.

    PubMed

    Koller, Theadora; Morgan, Antony; Guerreiro, Ana; Currie, Candace; Ziglio, Erio

    2009-09-01

    Over the past 25 years, the WHO collaborative cross-national Health Behaviour in School-aged Children (HBSC) study has been accumulating evidence that provides insights into how to promote the health and well-being of young people. HBSC has increased understanding of the determinants of young people's health, particularly in relation to the social contexts in which they live, learn and play. The study now spans 43 countries and regions in Europe and North America. HBSC provides intelligence for the development and evaluation of public health policy and practice at national, sub-national and international levels. However, the mere existence of evidence does not automatically change policy nor necessarily improve the lives of young people. Effective mechanisms to ensure use of evidence in policy-making and practice are needed. The WHO/HBSC Forum series is a platform designed to facilitate the translation of evidence into action. Forum processes convene researchers, policy-makers and practitioners from across Europe to analyse data, review policies and interventions, and identify lessons learned to improve the health of adolescents through actions that address the social contexts that influence their health. Each Forum process consists of case studies produced by interdisciplinary teams in countries and regions, cross-country evidence reviews, a European consultation, an outcomes statement within a final publication, and a Web-based knowledge platform. In addition to emphasizing the translation of research into action, the Forum series focuses on increasing know-how to scale up intersectoral policies and interventions; reduce health inequities; and involve young people in the design, implementation and evaluation of policies and interventions. Interviews with selected participants in the 2007 Forum process revealed that national-level impacts of involvement were: brokering new or strengthening existing working relationships among members of case study drafting teams

  14. Mach stem hysteresis: Experiments addressing a novel explanation of clumpy astrophysical jet emission

    NASA Astrophysics Data System (ADS)

    Yirak, K.; Foster, J. M.; Hartigan, P.; Wilde, B. H.; Douglas, M. R.; Paguio, R.; Blue, B. E.; Martinez, D.; Farley, D.; Rosen, P. A.; Frank, A.

    2013-06-01

    Recent time-series observations of shock waves in stellar jets taken with the Hubble Space Telescope reveal localized bright knots that persist over nearly 15 years. While some of these features represent shock fronts caused by variable velocities in the flow, others appear at the intersection points between distinct bow shocks. Theoretically, when the angle between two intersecting shocks exceeds a certain critical value, a third shock (Mach stem) should form. Because Mach stems form perpendicular to the direction of flow, incoming particles encounter a normal shock instead of an oblique one, which results in brighter emission at this location. To study this phenomenon in a controlled laboratory setting, we have carried out experiments on the Omega laser aimed at understanding the formation, growth, and destruction of Mach stems in the warm dense plasma regime. Our experimental results indicate how the growth rate depends upon included angle, and numerical simulations indicate that it may be possible to stabilize an already-formed Mach stem below the critical angle when certain conditions are satisfied.

  15. Addressing the Real-World Challenges in the Development of Propulsion IVHM Technology Experiment (PITEX)

    NASA Technical Reports Server (NTRS)

    Maul, William A.; Chicatelli, Amy; Fulton, Christopher E.; Balaban, Edward; Sweet, Adam; Hayden, Sandra Claire; Bajwa, Anupa

    2005-01-01

    The Propulsion IVHM Technology Experiment (PITEX) has been an on-going research effort conducted over several years. PITEX has developed and applied a model-based diagnostic system for the main propulsion system of the X-34 reusable launch vehicle, a space-launch technology demonstrator. The application was simulation-based using detailed models of the propulsion subsystem to generate nominal and failure scenarios during captive carry, which is the most safety-critical portion of the X-34 flight. Since no system-level testing of the X-34 Main Propulsion System (MPS) was performed, these simulated data were used to verify and validate the software system. Advanced diagnostic and signal processing algorithms were developed and tested in real-time on flight-like hardware. In an attempt to expose potential performance problems, these PITEX algorithms were subject to numerous real-world effects in the simulated data including noise, sensor resolution, command/valve talkback information, and nominal build variations. The current research has demonstrated the potential benefits of model-based diagnostics, defined the performance metrics required to evaluate the diagnostic system, and studied the impact of real-world challenges encountered when monitoring propulsion subsystems.

  16. Enhanced molten salt purification by electrochemical methods: feasibility experiments with flibe

    SciTech Connect

    Alan K Wertsching; Brandon S Grover; Pattrick Calderoni

    2010-09-01

    -chemistry properties in heat transport systems’ describes the options available to reach such objectives and contains extended references to published work. The report highlights how electrochemical methods are the most promising techniques for the development of instrumentation aimed at the measurement of melts composition and for enhanced purification systems. The purpose of this work is to summarize preliminary experimental activities performed at the INL Safety and Tritium Applied Research facility in support of the development of electrochemistry based instrumentation and purification systems. The experiments have been focused on the LiF-BeF2 eutectic (67 and 33 mol%, respectively), also known as flibe.

  17. Gravity is the Key Experiment to Address the Habitability of the Ocean in Jupiter's Moon Europa

    NASA Astrophysics Data System (ADS)

    Sessa, A. M.; Dombard, A. J.

    2013-12-01

    within the ice shell) dominate the Bouguer gravity. Thus, gravity can be used to explore this interface. To test whether active volcanism can be detected, we scale gravity models for the terrestrial planets down to a body the size of Europa's silicate core and with a density contrast consistent with a rock-water interface. Here, Venus and Earth serve as proxies for volcanically active bodies, while the Moon and Mars are proxies for inactive bodies. Additionally, we create gravity from synthetic topography on the base of the ice shell. Maps of the Bouguer-gravity and geoid anomalies reveal that active volcanism is characterized by small amplitudes (a few mGal and a few meters). Large-scale topography on the base of the ice shell adds larger geoid anomalies (tens of meters) but still small gravity anomalies. The absence of volcanic activity on the rock-water interface is likely characterized by larger anomalies (tens of mGal and tens of meters), plausibly because the cooler thermal structure permits the rocky lithosphere to support larger mass-density anomalies. Thus, study of the gravity may illuminate the habitability of Europa, and gravity and topography experiments on any future mission (e.g., the Europa Clipper) should be given the highest scientific priority.

  18. Addressing the mental health needs of looked after children in foster care: the experiences of foster carers.

    PubMed

    York, W; Jones, J

    2017-03-01

    WHAT IS KNOWN ON THE SUBJECT?: In the UK and internationally, the number of looked after children is increasing year on year. Mental health problems among looked after children are significantly higher than in the general population, and the uptake of mental health services for these children is low. There is a poor prognosis for children with untreated mental health problems; this is further compounded if the child is within the care system. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: This study adds to our understanding of foster carers' experiences of the mental health needs of looked after children and demonstrates some of the challenges associated with accessing appropriate and timely mental health services. New knowledge derived from this research is that the barriers to accessing Child and Adolescent Mental Health Services (CAMHS) are not at the time of initial referral as previously reported, but later, once within the mental health system with long waiting times experienced particularly for specialist services. This study provides new insights into the experience of being a foster carer and the levels of support and resources needed that directly relate to the viability of the placement. The majority of the foster carers interviewed were from a Black and Minority Ethnic (BME) background, previously under-represented in this research area. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: A number of areas in current CAMHS provision need addressing with a focus on accessibility, consultation and support for foster carers. Waiting times need to be addressed, and improved communication with other agencies is also highlighted. CAMHS nurses are well placed to develop and deliver a comprehensive care package to foster carers, offering more tailored support to them whilst enabling the children and young people in their care to access and engage more effectively with mental health services.

  19. The perfect boring situation-Addressing the experience of monotony during crewed deep space missions through habitability design

    NASA Astrophysics Data System (ADS)

    Peldszus, Regina; Dalke, Hilary; Pretlove, Stephen; Welch, Chris

    2014-01-01

    In contemporary orbital missions, workloads are so high and varied that crew may rarely experience stretches of monotony. However, in historical long duration missions, occurrences of monotony were, indeed, reported anecdotally by crew. Of the effective countermeasures that appear to be at hand, many rely on visual or logistical proximity to the Earth, and are not feasible in the remote context of an extended deep space mission scenario. There, particularly in- and outbound cruising stages would be characterised by longer, comparably uneventful periods of low workload, coupled with confinement and unchanging vehicle surroundings. While the challenge of monotony has been pointed out as an exploration-related research area, it has received less explicit attention from a habitation design perspective than other human behaviour and performance issues. The paper addresses this gap through a literature review of the theory and application of design-based mitigation strategies. It outlines models of emergence of monotony, situates the phenomenon in a remote mission context as a problem of sensory, social and spatio-temporal isolation, and discusses proposed countermeasures related to habitability. The scope of the literature is extended to primary sources in the form of a qualitative review of six onboard diaries from orbital and simulator missions, highlighting a range of habitat-related design themes. These are translated into the autonomous deep space setting with the overall rationale of integrating affordances into onboard habitation systems and placing emphasis on reinforcing positive situational characteristics.

  20. Correlation of Process Data and Electrochemical Noise to Assess Kraft Digester Corrosion: Spring Grove Experiment

    SciTech Connect

    Pawel, SJ

    2003-06-18

    Electrochemical noise (ECN) probes were deployed in a carbon steel continuous kraft digester at four locations and at one location in the bottom cone of the associated flash tank. The probes consisted of carbon steel electrodes, representing the vessel construction material, and 309LSi stainless steel overlay electrodes, representing the weld overlay repair in a portion of the vessel. Current and potential noise, the temperature at each probe location, and the value of about 32 process parameters (flow rates, liquor chemistry, etc.) were monitored continuously for a period of almost one year. Historical vessel inspection data and post-test evaluation of the probe components were used to assess/compare ECN corrosion activity with physical changes in wall thickness and corrosion patterns on the digester shell. In addition, attempts were made to correlate ECN activity from each electrode type with process parameters. The results indicate the high general corrosion rates of steel observed just below the extraction screens--on the order of 35 mils/y for the past few years--accelerated further during the period of probe deployment. The maximum wastage of steel (normalized to one full year exposure) was about 85 mils/y at the ring 6N probe just below the extraction screens. Consistent with recent historical observations, the steel corrosion rate at the ring 6S probe--at the same elevation but directly across the digester from ring 6N--was significantly lower at about 50 mils/y. Just prior to probe deployment, the digester shell below the extraction screens was overlaid with 309LSi stainless steel, which was observed to be essentially immune to corrosion at this location. While the ECN probes detected differences in electrochemical behavior between steel probes and between 309LSi probes at rings 6N and 6S, there was only poor quantitative correlation of current sums with actual corrosion rates at these locations. A significant contribution of redox reactions on both steel

  1. 2016 Senior Researcher Award Acceptance Address: Developing Productive Researchers Through Mentoring, Rethinking Doctoral Dissertations, and Facilitating Positive Publishing Experiences

    ERIC Educational Resources Information Center

    Sims, Wendy L.

    2016-01-01

    In her acceptance address, Wendy Sims provides a unique perspective based on thoughts and reflections resulting from her 8 years of service as the ninth Editor of the "Journal of Research in Music Education" ("JRME"). Specifically, she addresses how college-level music education researchers can promote positive attitudes toward…

  2. Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 9: Microscale Recovery of a Soil Metal Pollutant and Its Extractant

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; Balderas-Hernandez, Patricia; Garcia-Pintor, Elizabeth; Barba-Gonzalez, Sandy Nohemi; Doria-Serrano, Ma. del Carmen; Hernaiz-Arce, Lorena; Diaz-Perez, Armando; Lozano-Cusi, Ana

    2011-01-01

    Many soils throughout the world are contaminated with metal salts of diverse toxicity. We have developed an experiment to demonstrate the removal of a metal from an insoluble surrogate soil pollutant, CuCO[subscript 3] multiplied by Cu(OH)[subscript 2], by complexation followed by the simultaneous electrochemical recovery of the ligand (i.e.,…

  3. Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 8. Microscale Simultaneous Photocatalysis

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; Mena-Brito, Rodrigo; Fregoso-Infante, Arturo

    2005-01-01

    A microscale experiment in which the simultaneous oxidation of an organic compound and the reduction of a metal ion are photocatalytically performed in an aqueous slurry containing TiO[subscript 2] irradiated with UV light. This experiment can be performed in the laboratory session with simple chemicals and equipments.

  4. Correlation of Process Data and Electrochemical Noise to Assess Kraft Digester Corrosion: Kamloops Experiment

    SciTech Connect

    Pawel, SJ

    2002-05-09

    Electrochemical noise (ECN) probes were deployed in a carbon steel continuous kraft digester at five locations roughly equi-spaced from top to bottom of the vessel. Current and potential noise, the temperature at each probe location, and the value of about 60 process parameters (flow rates, liquor chemistry, etc.) were monitored continuously for a period of one year. Historical vessel inspection data, including inspections accomplished immediately prior to and immediately following probe deployment, and post-test evaluation of the probe components were used to assess/compare corrosion indications from the probes with physical changes in wall thickness and corrosion patterns on the digester shell. The results indicate that furnish composition is a significant variable influencing digester corrosion, with increasing amounts of Douglas fir in the nominal furnish correlating directly with increased corrosion activity on the ECN probes. All five probes detected changes in furnish composition approximately simultaneously, indicating rapid chemical communication through the liquor, but the effect was strongest and persisted longest relatively high in the digester. The ECN probes also indicate significant corrosion activity occurred at each probe position during shutdown/restart transients. Little or no correlation between ECN probe corrosion activity and other operational variables was observed. Post-test evaluation of the probes confirmed general corrosion of a magnitude that closely agreed with corrosion current sums calculated for each probe over the exposure period and with historical average corrosion rates for the respective locations. Further, no pitting was observed on any of the electrodes, which is consistent with the ECN data, relevant polarization curves developed for steel in liquor removed from the digester, and the post-test inspection of the digester.

  5. Laboratory Experiments on the Electrochemical Remediation of the Environment. Part 7: Microscale Production of Ozone

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; Mayen-Mondragon, Rodrigo; Moran-Moran, M. T.; Alatorre-Ordaz, Alejandro; Mattson, Bruce; Eskestrand, Scot

    2005-01-01

    Ozone is a powerful oxidant and disinfectant, which can be used to clean environment as well as obtain pure drinking water. A series of experiments to produce and test ozone with simple equipment and material are presented.

  6. APPLICATIONS OF ELECTROCHEMICAL IMMUNOSENSORS TO ENVIRONMENTAL MONITORING

    EPA Science Inventory

    This paper discusses basic electrochemical immunoassay technology. Factors limiting the practical application of antibodies to anlaytical problems are also presented. It addresses the potential use of immunoassay methods based on electrochemical detection for the analysis of env...

  7. A Concept Space Approach to Addressing the Vocabulary Problem in Scientific Information Retrieval: An Experiment on the Worm Community System.

    ERIC Educational Resources Information Center

    Chen, Hsinchun; Ng, Tobun D.; Martinez, Joanne; Schatz, Bruce R.

    1997-01-01

    Presents an algorithmic approach to addressing the vocabulary problem in scientific information retrieval and information sharing, using the molecular biology domain as an example. A cognitive study and a follow-up document retrieval study were conducted using first a conjoined fly-worm thesaurus and then an actual worm database and the conjoined…

  8. Opening Address

    NASA Astrophysics Data System (ADS)

    Yamada, T.

    2014-12-01

    Ladies and Gentlemen, it is my great honor and pleasure to present an opening address of the 3rd International Workshop on "State of the Art in Nuclear Cluster Physics"(SOTANCP3). On the behalf of the organizing committee, I certainly welcome all your visits to KGU Kannai Media Center belonging to Kanto Gakuin University, and stay in Yokohama. In particular, to whom come from abroad more than 17 countries, I would appreciate your participations after long long trips from your homeland to Yokohama. The first international workshop on "State of the Art in Nuclear Cluster Physics", called SOTANCP, was held in Strasbourg, France, in 2008, and the second one was held in Brussels, Belgium, in 2010. Then the third workshop is now held in Yokohama. In this period, we had the traditional 10th cluster conference in Debrecen, Hungary, in 2012. Thus we have the traditional cluster conference and SOTANCP, one after another, every two years. This obviously shows our field of nuclear cluster physics is very active and flourishing. It is for the first time in about 10 years to hold the international workshop on nuclear cluster physics in Japan, because the last cluster conference held in Japan was in Nara in 2003, about 10 years ago. The president in Nara conference was Prof. K. Ikeda, and the chairpersons were Prof. H. Horiuchi and Prof. I. Tanihata. I think, quite a lot of persons in this room had participated at the Nara conference. Since then, about ten years passed. So, this workshop has profound significance for our Japanese colleagues. The subjects of this workshop are to discuss "the state of the art in nuclear cluster physics" and also discuss the prospect of this field. In a couple of years, we saw significant progresses of this field both in theory and in experiment, which have brought better and new understandings on the clustering aspects in stable and unstable nuclei. I think, the concept of clustering has been more important than ever. This is true also in the

  9. Addressing healthcare.

    PubMed

    Daly, Rich

    2013-02-11

    Though President Barack Obama has rarely made healthcare references in his State of the Union addresses, health policy experts are hoping he changes that strategy this year. "The question is: Will he say anything? You would hope that he would, given that that was the major issue he started his presidency with," says Dr. James Weinstein, left, of the Dartmouth-Hitchcock health system.

  10. Electrochemical Sensors for Clinic Analysis

    PubMed Central

    Wang, You; Xu, Hui; Zhang, Jianming; Li, Guang

    2008-01-01

    Demanded by modern medical diagnosis, advances in microfabrication technology have led to the development of fast, sensitive and selective electrochemical sensors for clinic analysis. This review addresses the principles behind electrochemical sensor design and fabrication, and introduces recent progress in the application of electrochemical sensors to analysis of clinical chemicals such as blood gases, electrolytes, metabolites, DNA and antibodies, including basic and applied research. Miniaturized commercial electrochemical biosensors will form the basis of inexpensive and easy to use devices for acquiring chemical information to bring sophisticated analytical capabilities to the non-specialist and general public alike in the future. PMID:27879810

  11. Addressing end of life care issues in a tertiary treatment centre: lessons learned from surveying parents' experiences.

    PubMed

    Midson, Rosie; Carter, Bernie

    2010-03-01

    Much of the work in children's hospitals is rightly focused on treatments aimed towards cure but this means that death is often seen as a failure and, as such, it may not be discussed or acknowledged as a possibility until very late in a child's stay in hospital. However, this reluctance can deny the child and their family the opportunity to be informed, prepare and make choices. A survey of the care received by parents whose child had died in a children's tertiary treatment centre led to a greater understanding of the parents' experiences and the ways in which care could be enhanced. Parents talked of the way in which the geography of the hospital could be disruptive and dislocating and yet they often had no place to be alone or in private. Communication was identified as a core issue with many parents being positive about the quality and timing of communication. However, other parents expressed a preference for more preparation about the possibility that their child might die. Some parents had positive experiences of follow-up visits after their child's death, whilst others remained frustrated and some felt this visit had made them re-live the experiences. The importance of kind, supportive and consistent care was clearly evidenced by the parents when they spoke about their feelings and emotions. The findings helped to develop and implement an End of Life Care Pathway and a pathway tool which aimed to enhance parents' experiences and to improve care. A further survey was triggered by the concern that the pathway was not being fully utilized and it became apparent that, despite the tool, staff were still reluctant to provide anticipatory guidance, even though many practical aspects of care scored well. The need for good communication that prepares parents for the eventuality that their child might or will die is one of the clearest lessons from the second survey. This is important as anticipatory guidance opens up parents - and children's - choices, and their

  12. Tungsten impurity transport experiments in Alcator C-Mod to address high priority research and development for ITER

    SciTech Connect

    Loarte, A.; Polevoi, A. R.; Hosokawa, M.; Reinke, M. L.; Chilenski, M.; Howard, N.; Hubbard, A.; Hughes, J. W.; Rice, J. E.; Walk, J.; Köchl, F.; Pütterich, T.; Dux, R.; Zhogolev, V. E.

    2015-05-15

    Experiments in Alcator C-Mod tokamak plasmas in the Enhanced D-alpha H-mode regime with ITER-like mid-radius plasma density peaking and Ion Cyclotron Resonant heating, in which tungsten is introduced by the laser blow-off technique, have demonstrated that accumulation of tungsten in the central region of the plasma does not take place in these conditions. The measurements obtained are consistent with anomalous transport dominating tungsten transport except in the central region of the plasma where tungsten transport is neoclassical, as previously observed in other devices with dominant neutral beam injection heating, such as JET and ASDEX Upgrade. In contrast to such results, however, the measured scale lengths for plasma temperature and density in the central region of these Alcator C-Mod plasmas, with density profiles relatively flat in the core region due to the lack of core fuelling, are favourable to prevent inter and intra sawtooth tungsten accumulation in this region under dominance of neoclassical transport. Simulations of ITER H-mode plasmas, including both anomalous (modelled by the Gyro-Landau-Fluid code GLF23) and neoclassical transport for main ions and tungsten and with density profiles of similar peaking to those obtained in Alcator C-Mod show that accumulation of tungsten in the central plasma region is also unlikely to occur in stationary ITER H-mode plasmas due to the low fuelling source by the neutral beam injection (injection energy ∼ 1 MeV), which is in good agreement with findings in the Alcator C-Mod experiments.

  13. Introducing Astrophysics and Cosmology as Part of Multidisciplinary Approaches to Liberal Arts Courses Addressing "The Big Questions" of Human Experience

    NASA Astrophysics Data System (ADS)

    Wesney, J. C.

    2012-08-01

    There is an opportunity to bring college students to the exploration of the grandeur and wonder of the universe through the design and crafting of courses for the university and liberal arts curricula that would develop multidisciplinary perspectives within the frames of reference of astrophysics and cosmology. There is broad interest within colleges and universities to provide courses that examine "The Big Questions" of human experience from a variety of perspectives. The study of the history of discoveries and insights that we have gained through the development of astrophysics and cosmology provides course options for students to use to explore these questions. Such hybrid courses enable students to approach the questions of origins, human existence, appreciation of the natural world, appreciation of the universe at large, and the significance of our evolving comprehension of the universe from a variety of disciplinary perspectives, including those that border on the astrophysical and cosmological domains. There are within such courses opportunities to examine historical, philosophical, theological, and cultural perspectives as they intersect with our scientific understanding of where and who we are. The first of these courses at Sacred Heart University has been developed and presented for the past two years as part of the new Core Curriculum. The development of that course, entitled The Journey in the Physical Universe, will be discussed, and insights will be shared.

  14. Recommended minimal requirements and development guidelines for exposure setups of bio-experiments addressing the health risk concern of wireless communications.

    PubMed

    Kuster, N; Schönborn, F

    2000-10-01

    The evidence currently available on the potential health effects from electromagnetic field (EMF) exposure has been largely judged as being too tentative and inadequate to meet criteria for assessing health risks. Some of the main reasons for these shortcomings lie in the incomplete description of the exposure and poorly characterized dosimetry. Well-defined exposure conditions are essential to obtain reproducible and scientifically valuable results. To facilitate the development of optimized setups for specific bio-experiments, this paper lists basic requirements and provides development guidelines for evaluation, optimization, construction, and verification of exposure. In addition, definitions of minimum performance requirements for setups addressing the health risk concern of wireless communications are suggested.

  15. Inaugural address

    NASA Astrophysics Data System (ADS)

    Joshi, P. S.

    2014-03-01

    From jets to cosmos to cosmic censorship P S Joshi Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005, India E-mail: psj@tifr.res.in 1. Introduction At the outset, I should like to acknowledge that part of the title above, which tries to capture the main flavour of this meeting, and has been borrowed from one of the plenary talks at the conference. When we set out to make the programme for the conference, we thought of beginning with observations on the Universe, but then we certainly wanted to go further and address deeper questions, which were at the very foundations of our inquiry, and understanding on the nature and structure of the Universe. I believe, we succeeded to a good extent, and it is all here for you in the form of these Conference Proceedings, which have been aptly titled as 'Vishwa Mimansa', which could be possibly translated as 'Analysis of the Universe'! It is my great pleasure and privilege to welcome you all to the ICGC-2011 meeting at Goa. The International Conference on Gravitation and Cosmology (ICGC) series of meetings are being organized by the Indian Association for General Relativity and Gravitation (IAGRG), and the first such meeting was planned and conducted in Goa in 1987, with subsequent meetings taking place at a duration of about four years at various locations in India. So, it was thought appropriate to return to Goa to celebrate the 25 years of the ICGC meetings. The recollections from that first meeting have been recorded elsewhere here in these Proceedings. The research and teaching on gravitation and cosmology was initiated quite early in India, by V V Narlikar at the Banares Hindu University, and by N R Sen in Kolkata in the 1930s. In course of time, this activity grew and gained momentum, and in early 1969, at the felicitation held for the 60 years of V V Narlikar at a conference in Ahmedabad, P C Vaidya proposed the formation of the IAGRG society, with V V Narlikar being the first President. This

  16. Convocation address.

    PubMed

    Kakodkar, A

    1999-07-01

    This convocation addressed by Dr. Anil Kakodkar focuses on the challenges faced by graduating students. In his speech, he emphasized the high level of excellence achieved by the industrial sector; however, he noted that there has been a loss of initiative in maximizing value addition, which was worsened by an increasing population pressure. In facing a stiff competition in the external and domestic markets, it is imperative to maximize value addition within the country in a competitive manner and capture the highest possible market share. To achieve this, high-quality human resources are central. Likewise, family planning programs should become more effective and direct available resources toward national advantage. To boost the domestic market, he suggests the need to search for strengths to achieve leadership position in those areas. First, an insight into the relationship between the lifestyles and the needs of our people and the natural resource endowment must be gained. Second, remodeling of the education system must be undertaken to prepare the people for adding the necessary innovative content in our value addition activities. Lastly, Dr. Kakodkar emphasizes the significance of developing a strong bond between parents and children to provide a sound foundation and allow the education system to grow upon it.

  17. Method for the electro-addressable functionalization of electrode arrays

    DOEpatents

    Harper, Jason C.; Polsky, Ronen; Dirk, Shawn M.; Wheeler, David R.; Arango, Dulce C.; Brozik, Susan M.

    2015-12-15

    A method for preparing an electrochemical biosensor uses bias-assisted assembly of unreactive -onium molecules on an electrode array followed by post-assembly electro-addressable conversion of the unreactive group to a chemical or biological recognition group. Electro-addressable functionalization of electrode arrays enables the multi-target electrochemical sensing of biological and chemical analytes.

  18. Presidential address.

    PubMed

    Vohra, U

    1993-07-01

    The Secretary of India's Ministry of Health and Family Welfare serves as Chair of the Executive Council of the International Institute for Population Sciences in Bombay. She addressed its 35th convocation in 1993. Global population stands at 5.43 billion and increases by about 90 million people each year. 84 million of these new people are born in developing countries. India contributes 17 million new people annually. The annual population growth rate in India is about 2%. Its population size will probably surpass 1 billion by the 2000. High population growth rates are a leading obstacle to socioeconomic development in developing countries. Governments of many developing countries recognize this problem and have expanded their family planning programs to stabilize population growth. Asian countries that have done so and have completed the fertility transition include China, Japan, Singapore, South Korea, and Thailand. Burma, Malaysia, North Korea, Sri Lanka, and Vietnam have not yet completed the transition. Afghanistan, Bangladesh, Iran, Nepal, and Pakistan are half-way through the transition. High population growth rates put pressure on land by fragmenting finite land resources, increasing the number of landless laborers and unemployment, and by causing considerable rural-urban migration. All these factors bring about social stress and burden civic services. India has reduced its total fertility rate from 5.2 to 3.9 between 1971 and 1991. Some Indian states have already achieved replacement fertility. Considerable disparity in socioeconomic development exists among states and districts. For example, the states of Bihar, Madhya Pradesh, Rajasthan, and Uttar Pradesh have female literacy rates lower than 27%, while that for Kerala is 87%. Overall, infant mortality has fallen from 110 to 80 between 1981 and 1990. In Uttar Pradesh, it has fallen from 150 to 98, while it is at 17 in Kerala. India needs innovative approaches to increase contraceptive prevalence rates

  19. President's Address

    PubMed Central

    Craig, Maurice

    1928-01-01

    Conditions which experience has proved conducive to mental disturbance considered.—Suggestions as to their treatment.—A weakened inhibition, rather than any positive condition, is probably the most important factor in the production of the exhaustion psycho-neuroses or psychoses. This view is supported by the prophylactic value of giving for prolonged periods small doses of bromide to hypersensitive children or to highly-strung persons exposed to stress or tropical climate, etc.—Pavlov's work on the conditioned reflexes in dogs quoted in support of the author's clinical experience: Pavlov states that bromides should not be regarded as sedatives, diminishing the excitability of the central nervous system, but as simply regulating the nervous system by strengthening the intensity of internal inhibition. This agrees with the author's clinical experience, as small doses of bromide taken regularly over a period of many years do not diminish the mental powers but in fact increase them. Question of sleeplessness considered with regard to the way in which sedatives act. Most of these do not act as so-called “sleeping draughts”; research may ultimately show that their action is to strengthen a weakened inhibition and that sleep is only a secondary benefit.—Value of sedatives before and after surgical operation. Importance of toxæmia in the production of mental disorder; insomnia often precedes a toxic process and permits it to become active. The theory of weakened inhibition explains many problems; e.g., why certain brilliant children or adults break down and why at first there is no interference with their normal mental activity which only becomes involved as sleep and other bodily functions become affected; why a toxæmia may affect the nervous system of certain people; why a breakdown may follow over-stimulation or occur with advancing years; why some persons relapse when certain treatment is discontinued; why treatment should at times be continuous, and why

  20. Welcome Address

    NASA Astrophysics Data System (ADS)

    Kiku, H.

    2014-12-01

    Ladies and Gentlemen, It is an honor for me to present my welcome address in the 3rd International Workshop on "State of the Art in Nuclear Cluster Physics"(SOTANCP3), as the president of Kanto Gakuin University. Particularly to those from abroad more than 17 countries, I am very grateful for your participation after long long trips from your home to Yokohama. On the behalf of the Kanto Gakuin University, we certainly welcome your visit to our university and stay in Yokohama. First I would like to introduce Kanto Gakuin University briefly. Kanto Gakuin University, which is called KGU, traces its roots back to the Yokohama Baptist Seminary founded in 1884 in Yamate, Yokohama. The seminary's founder was Albert Arnold Bennett, alumnus of Brown University, who came to Japan from the United States to establish a theological seminary for cultivating and training Japanese missionaries. Now KGU is a major member of the Kanto Gakuin School Corporation, which is composed of two kindergartens, two primary schools, two junior high schools, two senior high schools as well as KGU. In this university, we have eight faculties with graduate school including Humanities, Economics, Law, Sciences and Engineering, Architecture and Environmental Design, Human and Environmental Studies, Nursing, and Law School. Over eleven thousands students are currently learning in our university. By the way, my major is the geotechnical engineering, and I belong to the faculty of Sciences and Engineering in my university. Prof. T. Yamada, here, is my colleague in the same faculty. I know that the nuclear physics is one of the most active academic fields in the world. In fact, about half of the participants, namely, more than 50 scientists, come from abroad in this conference. Moreover, I know that the nuclear physics is related to not only the other fundamental physics such as the elementary particle physics and astrophysics but also chemistry, medical sciences, medical cares, and radiation metrology

  1. Physiological fluctuations in brain temperature as a factor affecting electrochemical evaluations of extracellular glutamate and glucose in behavioral experiments.

    PubMed

    Kiyatkin, Eugene A; Wakabayashi, Ken T; Lenoir, Magalie

    2013-05-15

    The rate of any chemical reaction or process occurring in the brain depends on temperature. While it is commonly believed that brain temperature is a stable, tightly regulated homeostatic parameter, it fluctuates within 1-4 °C following exposure to salient arousing stimuli and neuroactive drugs, and during different behaviors. These temperature fluctuations should affect neural activity and neural functions, but the extent of this influence on neurochemical measurements in brain tissue of freely moving animals remains unclear. In this Review, we present the results of amperometric evaluations of extracellular glutamate and glucose in awake, behaving rats and discuss how naturally occurring fluctuations in brain temperature affect these measurements. While this temperature contribution appears to be insignificant for glucose because its extracellular concentrations are large, it is a serious factor for electrochemical evaluations of glutamate, which is present in brain tissue at much lower levels, showing smaller phasic fluctuations. We further discuss experimental strategies for controlling the nonspecific chemical and physical contributions to electrochemical currents detected by enzyme-based biosensors to provide greater selectivity and reliability of neurochemical measurements in behaving animals.

  2. Opening address

    NASA Astrophysics Data System (ADS)

    Castagnoli, C.

    1994-01-01

    representation of the mole. Most of you, I presume, are neo-Pythagoreans, and consequently believe that a new definition and, maybe, a new realization of the unit of mass will be based on a number of atoms of silicon, a view which will certainly lead you to cross swords with the "electrical party". The importance of NA is also linked to the considerable and far-reaching return in other scientific and industrial fields. Finally, let me add that, ethically, the work of many persons all over the world and the money and energy they spend in order to add a decimal figure, may be an example of commitment to be given to our students. Last but not least, my warm thanks to the Director of the Istituto di Metrologia "G Colonnetti", where the experiment has been in progress since 1971, and to all the researchers involved in this work. I do hope that the National Council of Research will continue to support this important project. While wishing you a pleasant stay in Turin, I express the hope that our meeting will prove a fruitful opportunity for discussion and exchange of views.

  3. Understanding and addressing stigma and attachment insecurity in HIV-positive women who experience intimate partner violence: a model of medical and psychosocial care.

    PubMed

    Davis, Katy B

    2012-01-01

    Low-income women of color who are HIV positive and living in violent relationships are at significant risk for stigma and problems with attachment security. This article explores the ways in which these women may experience internalized stigma from incorporating society's negative views of HIV and domestic violence. It also addresses the ways in which insecure attachment may develop or intensify in this population through violence in their adult intimate relationships and/or living with a life threatening illness. A model of medical and psychosocial care utilized at the Women's HIV Program at the University of California San Francisco is offered as an intervention to reduce stigma and enhance healthy attachment. Clinical examples demonstrate how this system of medical and psychosocial care can help women in this situation establish stability and improve their lives despite the intense challenges they face.

  4. Electrochemical Engineering

    ERIC Educational Resources Information Center

    Alkire, Richard

    1976-01-01

    Discusses an electrochemical engineering course that combines transport phenomena and basic physical chemistry. Lecture notes and homework problems are used instead of a textbook; an outline of lecture topics is presented. (MLH)

  5. Enhancing capacities of riparian professionals to address and resolve transboundary issues in international river basins: experiences from the Lower Mekong River Basin

    NASA Astrophysics Data System (ADS)

    Douven, W.; Mul, M. L.; Fernández-Álvarez, B.; Hung, S. Lam; Bakker, N.; Radosevich, G.; van der Zaag, P.

    2012-09-01

    This paper analyses the design and impact of capacity building programmes aimed at enhancing capacities of riparian professionals to address and resolve transboundary issues in international river basins. The case study is a programme developed by the Mekong River Commission (MRC). A post-training evaluation was applied to assess its impact in terms of individual capacity enhancement and change (use and application of knowledge, factors hampering application, and change in function and opportunities within the organisation). The design of the Capacity Building Programme of the MRC Flood Management and Mitigation Programme required a well balanced range of subjects (such as IWRM (integrated water resources management), model and decision support systems, and international water law). The post-training evaluation, 6 months after the last training workshop, showed an increase in familiarity with the topics for all 37 respondents, with the highest increase for the respondents with few years of working experience and from training and education institutions. The relevance of the subjects taught was highlighted by 95% of the respondents, and 78% of the participants had already used some of the acquired knowledge in their job. The respondents indicated that they did not have sufficient opportunities to apply all knowledge. The phased implementation and training of lecturers during the training workshops had a good impact, directly through increasing involvement in facilitation and delivery of the capacity building programme and through the use of the knowledge gained in short courses and development of curricula at their institute. For these types of capacity building programmes, a few recommendations can be made. The selection of participants is crucial for the application of the learned knowledge in their work. The integrative nature of transboundary water issues calls for a capacity building programme addressing a wide range of subjects, which can be understood by a

  6. Enhancing capacities of riparian professionals to address and resolve transboundary issues in international river basins: experiences from the Lower Mekong River Basin

    NASA Astrophysics Data System (ADS)

    Douven, W.; Mul, M. L.; Álvarez, B. F.; Son, L. H.; Bakker, N.; Radosevich, G.; van der Zaag, P.

    2012-03-01

    This paper analyses the design and impact of capacity building programmes aimed at enhancing capacities of riparian professionals to address and resolve transboundary issues in international river basins. Case study is a programme developed by the Mekong River Commission (MRC). A post training evaluation was applied to assess its impact in terms of individual capacity enhancement and change (use and application of knowledge, factors hampering application, and change in function and opportunities within their organisation). The design of the Capacity Building Programme of the MRC Flood Management and Mitigation Programme showed a well balanced range of subjects (such as IWRM, models and decision support systems and international water law) which are required for such an integrated topic. The post training evaluation, 6 months after the last training workshop, showed the increase in familiarity of the topics for all 37 respondents, with highest increase for the respondents with few years of working experience and from training and educational institutions. The relevance of the subjects taught is shown by the fact that 95% of the respondents indicated they saw the relevance of the subjects and 78% had already used some knowledge acquired in their job. The respondents also indicated that they did not have sufficient opportunities to apply all knowledge acquired. The phased implementation and training of lecturers during the training workshops, had a good impact, directly through increasing involvement in facilitation and delivery of the capacity building programme and through the use of the knowledge gained in short courses and development of curricula at their training institute. For these types of capacity building programmes, a few recommendations can be made. The selection of participants is crucial for the application of the learned knowledge in their work. The integrative nature of transboundary water issues calls for a capacity building programme addressing a

  7. Electrochemical Techniques

    SciTech Connect

    Chen, Gang; Lin, Yuehe

    2008-07-20

    Sensitive and selective detection techniques are of crucial importance for capillary electrophoresis (CE), microfluidic chips, and other microfluidic systems. Electrochemical detectors have attracted considerable interest for microfluidic systems with features that include high sensitivity, inherent miniaturization of both the detection and control instrumentation, low cost and power demands, and high compatibility with microfabrication technology. The commonly used electrochemical detectors can be classified into three general modes: conductimetry, potentiometry, and amperometry.

  8. The Role of Eye Movement Desensitization and Reprocessing (EMDR) Therapy in Medicine: Addressing the Psychological and Physical Symptoms Stemming from Adverse Life Experiences

    PubMed Central

    Shapiro, Francine

    2014-01-01

    Background: A substantial body of research shows that adverse life experiences contribute to both psychological and biomedical pathology. Eye movement desensitization and reprocessing (EMDR) therapy is an empirically validated treatment for trauma, including such negative life experiences as commonly present in medical practice. The positive therapeutic outcomes rapidly achieved without homework or detailed description of the disturbing event offer the medical community an efficient treatment approach with a wide range of applications. Methods: All randomized studies and significant clinical reports related to EMDR therapy for treating the experiential basis of both psychological and somatic disorders are reviewed. Also reviewed are the recent studies evaluating the eye movement component of the therapy, which has been posited to contribute to the rapid improvement attributable to EMDR treatment. Results: Twenty-four randomized controlled trials support the positive effects of EMDR therapy in the treatment of emotional trauma and other adverse life experiences relevant to clinical practice. Seven of 10 studies reported EMDR therapy to be more rapid and/or more effective than trauma-focused cognitive behavioral therapy. Twelve randomized studies of the eye movement component noted rapid decreases in negative emotions and/or vividness of disturbing images, with an additional 8 reporting a variety of other memory effects. Numerous other evaluations document that EMDR therapy provides relief from a variety of somatic complaints. Conclusion: EMDR therapy provides physicians and other clinicians with an efficient approach to address psychological and physiologic symptoms stemming from adverse life experiences. Clinicians should therefore evaluate patients for experiential contributors to clinical manifestations. PMID:24626074

  9. Scanning electrochemical cell microscopy: theory and experiment for quantitative high resolution spatially-resolved voltammetry and simultaneous ion-conductance measurements.

    PubMed

    Snowden, Michael E; Güell, Aleix G; Lai, Stanley C S; McKelvey, Kim; Ebejer, Neil; O'Connell, Michael A; Colburn, Alexander W; Unwin, Patrick R

    2012-03-06

    Scanning electrochemical cell microscopy (SECCM) is a high resolution electrochemical scanning probe technique that employs a dual-barrel theta pipet probe containing electrolyte solution and quasi-reference counter electrodes (QRCE) in each barrel. A thin layer of electrolyte protruding from the tip of the pipet ensures that a gentle meniscus contact is made with a substrate surface, which defines the active surface area of an electrochemical cell. The substrate can be an electrical conductor, semiconductor, or insulator. The main focus here is on the general case where the substrate is a working electrode, and both ion-conductance measurements between the QRCEs in the two barrels and voltammetric/amperometric measurements at the substrate can be made simultaneously. In usual practice, a small perpendicular oscillation of the probe with respect to the substrate is employed, so that an alternating conductance current (ac) develops, due to the change in the dimensions of the electrolyte contact (and hence resistance), as well as the direct conductance current (dc). It is shown that the dc current can be predicted for a fixed probe by solving the Nernst-Planck equation and that the ac response can also be derived from this response. Both responses are shown to agree well with experiment. It is found that the pipet geometry plays an important role in controlling the dc conductance current and that this is easily measured by microscopy. A key feature of SECCM is that mass transport to the substrate surface is by diffusion and, for charged analytes, ion migration which can be controlled and varied quantifiably via the bias between the two QRCEs. For a working electrode substrate this means that charged redox-active analytes can be transported to the electrode/solution interface in a well-defined and controllable manner and that relatively fast heterogeneous electron transfer kinetics can be studied. The factors controlling the voltammetric response are determined by

  10. Using a storyboarding technique in the classroom to address end of life experiences in practice and engage student nurses in deeper reflection.

    PubMed

    Lillyman, Sue; Gutteridge, Robin; Berridge, Pat

    2011-05-01

    This paper evaluates the use of storyboarding within a classroom setting as a means of addressing end of life issues and engaging second year student nurses in creative, critical thinking and deeper reflection on practice. Storyboarding is a process that was developed to encourage learners to use the creative right brain and the critical left brain to formulate ideas in front of a group and then to look at those ideas critically (Lottier, 1986). The session was evaluated using a questionnaire and group discussion to elicit perceived learning from students. The activity was to create the storyboards in small groups, then review the content generated by discussion with the whole group. Main themes identified by the students included breaking bad news, dealing with cardiac arrest situation, coping with families following bereavement and the dying patient. Evaluation of the teaching session suggested that students found storyboarding helped to identify cultural aspects and feelings related to the dying patient. Students valued sharing with each other and the opportunity to have their experiences heard. It was noted that although this method provided as valuable learning experience for the student it is staff and time intensive and attention is required to establish a climate of trust and safety. The risk of exposing unexpected emotions within individual students appears no greater than with other approaches to teaching about loss, death and dying.

  11. Electrochemical strain microscopy time spectroscopy: Model and experiment on LiMn{sub 2}O{sub 4}

    SciTech Connect

    Amanieu, Hugues-Yanis; Thai, Huy N. M. Schröder, Jörg; Luchkin, Sergey Yu.; Rosato, Daniele; Lupascu, Doru C.; Keip, Marc-André; Kholkin, Andrei L.

    2015-08-07

    Electrochemical Strain Microscopy (ESM) can provide useful information on ionic diffusion in solids at the local scale. In this work, a finite element model of ESM measurements was developed and applied to commercial lithium manganese (III,IV) oxide (LiMn{sub 2}O{sub 4}) particles. ESM time spectroscopy was used, where a direct current (DC) voltage pulse locally disturbs the spatial distribution of mobile ions. After the pulse is off, the ions return to equilibrium at a rate which depends on the Li diffusivity in the material. At each stage, Li diffusivity is monitored by measuring the ESM response to a small alternative current (AC) voltage simultaneously applied to the tip. The model separates two different mechanisms, one linked to the response to DC bias and another one related to the AC excitation. It is argued that the second one is not diffusion-driven but is rather a contribution of the sum of several mechanisms with at least one depending on the lithium ion concentration explaining the relaxation process. With proper fitting of this decay, diffusion coefficients of lithium hosts could be extracted. Additionally, the effect of phase transition in LiMn{sub 2}O{sub 4} is taken into account, explaining some experimental observations.

  12. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Vissers, Donald R.; Prakash, Jai

    1994-01-01

    An electrochemical cell having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm.sup.3 ; the cell can be 90% recharged in three hours and can operate at temperatures below 160.degree. C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6.times.10.sup.4 cm.sup.2 /g of Ni.

  13. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Vissers, Donald R.; Prakash, Jai

    1996-01-01

    An electrochemical cell having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm.sup.3 ; the cell can be 90% recharged in three hours and can operate at temperatures below 160.degree. C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6.times.10.sup.4 cm.sup.2 /g of Ni.

  14. Electrochemical cell

    DOEpatents

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1996-07-16

    An electrochemical cell is described having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm{sup 3}; the cell can be 90% recharged in three hours and can operate at temperatures below 160 C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6{times}10{sup 4}cm{sup 2}/g of Ni. 6 figs.

  15. Electrochemical cell

    DOEpatents

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1994-02-01

    An electrochemical cell is described having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm[sup 3]; the cell can be 90% recharged in three hours and can operate at temperatures below 160 C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6[times]10[sup 4] cm[sup 2]/g of Ni. 8 figures.

  16. Electrochemical device

    DOEpatents

    Grimes, Patrick G.; Einstein, Harry; Bellows, Richard J.

    1988-01-12

    A tunnel protected electrochemical device features channels fluidically communicating between manifold, tunnels and cells. The channels are designed to provide the most efficient use of auxiliary power. The channels have a greater hydraulic pressure drop and electrical resistance than the manifold. This will provide a design with the optimum auxiliary energy requirements.

  17. Electrochemical construction

    DOEpatents

    Einstein, Harry; Grimes, Patrick G.

    1983-08-23

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  18. Electrochemical capacitor

    DOEpatents

    Anderson, Marc A.; Liu, Kuo -Chuan; Mohr, Charles M.

    1999-10-05

    An inexpensive porous metal oxide material having high surface area, good conductivity and high specific capacitance is advantageously used in an electrochemical capacitor. The materials are formed in a sol-gel process which affords control over the properties of the resultant metal oxide materials.

  19. Electrochemical Engineering.

    ERIC Educational Resources Information Center

    Alkire, Richard C.

    1983-01-01

    Discusses engineering ramifications of electrochemistry, focusing on current/potential distribution, evaluation of trade-offs between influences of different phenomena, use of dimensionless numbers to assist in scale-over to new operating conditions, and economics. Also provides examples of electrochemical engineering education content related to…

  20. Electrochemical Epitaxy

    DTIC Science & Technology

    1994-06-25

    formation. Frequently, the first atmic layer of the depositing element forms at a potential prior to, under, that needed to deposit the bulk element. Thiis...ps referred to as undepotential deposition (UPD). UPD is an importaM well studied and reviewed area of electrochemical surface science [4-6]. In...general, UPD results in deposits one atom thick (an atomic layer), although the absolute coveage is fequmty some function of the deposition potential. In

  1. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Vissers, Donald R.; Prakash, Jai

    1994-01-01

    An electrochemical cell having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a .beta." alumina electrolyte and NaAlCl.sub.4 or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose.

  2. Electrochemical cell

    SciTech Connect

    Walsh, F.M.

    1986-12-23

    This patent describes an electrochemical cell having a metal anode wherein the metal is selected from zinc and cadmium; a bromine cathode; and an aqueous electrolyte containing a metal bromide, the metal bromide having the same metal as the metal of the anode. The improvement described here comprises: a bromine complexing agent in the aqueous metal bromide electrolyte, the complexing agent consisting solely of a quaternary ammonium salt of an N-organo substituted alpha amino acid, ester, or betaine.

  3. Electrochemical cell

    DOEpatents

    Redey, L.I.; Myles, K.M.; Vissers, D.R.; Prakash, J.

    1996-07-02

    An electrochemical cell is described with a positive electrode having an electrochemically active layer of at least one transition metal chloride. A negative electrode of an alkali metal and a compatible electrolyte including an alkali metal salt molten at cell operating temperature is included in the cell. The electrolyte is present at least partially as a corrugated {beta}{double_prime} alumina tube surrounding the negative electrode interior to the positive electrode. The ratio of the volume of liquid electrolyte to the volume of the positive electrode is in the range of from about 0.1 to about 3. A plurality of stacked electrochemical cells is disclosed each having a positive electrode, a negative electrode of an alkali metal molten at cell operating temperature, and a compatible electrolyte. The electrolyte is at least partially present as a corrugated {beta}{double_prime} alumina sheet separating the negative electrode and interior to the positive electrodes. The alkali metal is retained in a porous electrically conductive ceramic, and seals for sealing the junctures of the electrolyte and the adjacent electrodes at the peripheries thereof. 8 figs.

  4. Electrochemical cell

    DOEpatents

    Redey, Laszlo I.; Myles, Kevin M.; Vissers, Donald R.; Prakash, Jai

    1996-01-01

    An electrochemical cell with a positive electrode having an electrochemically active layer of at least one transition metal chloride. A negative electrode of an alkali metal and a compatible electrolyte including an alkali metal salt molten at cell operating temperature is included in the cell. The electrolyte is present at least partially as a corrugated .beta." alumina tube surrounding the negative electrode interior to the positive electrode. The ratio of the volume of liquid electrolyte to the volume of the positive electrode is in the range of from about 0.1 to about 3. A plurality of stacked electrochemical cells is disclosed each having a positive electrode, a negative electrode of an alkali metal molten at cell operating temperature, and a compatible electrolyte. The electrolyte is at least partially present as a corrugated .beta." alumina sheet separating the negative electrode and interior to the positive electrodes. The alkali metal is retained in a porous electrically conductive ceramic, and seals for sealing the junctures of the electrolyte and the adjacent electrodes at the peripheries thereof.

  5. Electrochemical cell

    DOEpatents

    Nagy, Zoltan; Yonco, Robert M.; You, Hoydoo; Melendres, Carlos A.

    1992-01-01

    An electrochemical cell has a layer-type or sandwich configuration with a Teflon center section that houses working, reference and counter electrodes and defines a relatively narrow electrolyte cavity. The center section is surrounded on both sides with thin Teflon membranes. The membranes are pressed in place by a pair of Teflon inner frames which are in turn supported by a pair of outer metal frames. The pair of inner and outer frames are provided with corresponding, appropriately shaped slits that are in plane generally transverse to the plane of the working electrode and permit X-ray beams to enter and exit the cell through the Teflon membranes that cover the slits so that the interface between the working electrode and the electrolyte within the cell may be analyzed by transmission geometry. In one embodiment, the center section consists of two parts, one on top of the other. Alternatively, the center section of the electrochemical cell may consist of two intersliding pieces or may be made of a single piece of Teflon sheet material. The electrolyte cavity is shaped so that the electrochemical cell can be rotated 90.degree. in either direction while maintaining the working and counter electrodes submerged in the electrolyte.

  6. Electrochemical cell

    DOEpatents

    Nagy, Z.; Yonco, R.M.; You, H.; Melendres, C.A.

    1992-08-25

    An electrochemical cell has a layer-type or sandwich configuration with a Teflon center section that houses working, reference and counter electrodes and defines a relatively narrow electrolyte cavity. The center section is surrounded on both sides with thin Teflon membranes. The membranes are pressed in place by a pair of Teflon inner frames which are in turn supported by a pair of outer metal frames. The pair of inner and outer frames are provided with corresponding, appropriately shaped slits that are in plane generally transverse to the plane of the working electrode and permit X-ray beams to enter and exit the cell through the Teflon membranes that cover the slits so that the interface between the working electrode and the electrolyte within the cell may be analyzed by transmission geometry. In one embodiment, the center section consists of two parts, one on top of the other. Alternatively, the center section of the electrochemical cell may consist of two intersliding pieces or may be made of a single piece of Teflon sheet material. The electrolyte cavity is shaped so that the electrochemical cell can be rotated 90[degree] in either direction while maintaining the working and counter electrodes submerged in the electrolyte. 5 figs.

  7. How to ensure that the results of climate risk analysis make a difference? - Experience from applied research addressing the challenges of climate change

    NASA Astrophysics Data System (ADS)

    Schneiderbauer, Stefan; Zebisch, Marc; Becker, Daniel; Pedoth, Lydia; Renner, Kathrin; Kienberger, Stefan

    2016-04-01

    Changing climate conditions may have beneficial or adverse effects on the social-ecological systems we are living in. In any case, the possible effects result from complex and interlinked physical and social processes embedded in these systems. Traditional research addresses these bio-physical and societal issues in a separate way. Therefore, in general, studies on risks related to climate change are still mono-disciplinary in nature with an increasing amount of work following a multi-disciplinary approach. The quality and usefulness of the results of such research for policy or decision making in practice may further be limited by study designs that do not acknowledge appropriately the significance of integrating or at least mixing qualitative and quantitative information and knowledge. Finally, the acceptance of study results - particularly when containing some kind of assessments - is often endangered by insufficient and / or late involvement of stakeholders and users. The above mentioned limitations have often been brought up in the recent past. However, despite that a certain consensus could be achieved in the last years recognising the need to tackle these issues, little progress has been made in terms of implementation within the context of (research) studies. This paper elaborates in detail on reasons that hamper the application of - interdisciplinary (i.e. natural and social science), - trans-disciplinary (i.e. co-production of knowledge) and - integrative (i.e. combining qualitative and quantitative approaches) work. It is based on the experience gained through a number of applied climate change vulnerability studies carried out within the context of various GIZ-financed development cooperation projects, a consultancy project for the German Environment Agency as well as the workshop series INQUIMUS, which tackles particularly the issues of mixing qualitative and quantitative research approaches. Potentials and constraints of possible attempts for

  8. Electrochemical spectroscopy of conjugated polymers

    NASA Astrophysics Data System (ADS)

    Hwang, Jungseek

    levels of the conjugated polymer film on the electrodes reversibly. Our experiments have addressed four aspects: (1) electrochromism of PEDOT and PProDOT-Me2, (2) optimization of the thickness of the films in the cells for the greatest change in infrared reflectance (which is related to the polymer absorbance), (3) the switching time of the cells, and (4) the lifetime of the cells. The latter is very important for practical applications. We present the results of these studies and discussions. We also give some comments and ideas for further study.

  9. Electrochemical cell

    DOEpatents

    Kaun, Thomas D.

    1984-01-01

    An improved secondary electrochemical cell is disclosed having a negative electrode of lithium aluminum, a positive electrode of iron sulfide, a molten electrolyte of lithium chloride and potassium chloride, and the combination that the fully charged theoretical capacity of the negative electrode is in the range of 0.5-1.0 that of the positive electrode. The cell thus is negative electrode limiting during discharge cycling. Preferably, the negative electrode contains therein, in the approximate range of 1-10 volume % of the electrode, an additive from the materials of graphitized carbon, aluminum-iron alloy, and/or magnesium oxide.

  10. Electrochemical cell

    DOEpatents

    Kaun, T.D.

    An improved secondary electrochemical cell is disclosed having a negative electrode of lithium aluminum, a positive electrode of iron sulfide, a molten electrolyte of lithium chloride and potassium chloride, and the combination that the fully charged theoretical capacity of the negative electrode is in the range of 0.5 to 1.0 that of the positive electrode. The cell thus is negative electrode limiting during discharge cycling. Preferably, the negative electrode contains therein, in the approximate range of 1 to 10 volume % of the electrode, an additive from the materials of graphitized carbon, aluminum-iron alloy, and/or magnesium oxide.

  11. Electrochemical cell

    DOEpatents

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1994-08-23

    An electrochemical cell is described having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a [beta] alumina electrolyte and NaAlCl[sub 4] or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose. 6 figs.

  12. CMOS Electrochemical Instrumentation for Biosensor Microsystems: A Review.

    PubMed

    Li, Haitao; Liu, Xiaowen; Li, Lin; Mu, Xiaoyi; Genov, Roman; Mason, Andrew J

    2016-12-31

    Modern biosensors play a critical role in healthcare and have a quickly growing commercial market. Compared to traditional optical-based sensing, electrochemical biosensors are attractive due to superior performance in response time, cost, complexity and potential for miniaturization. To address the shortcomings of traditional benchtop electrochemical instruments, in recent years, many complementary metal oxide semiconductor (CMOS) instrumentation circuits have been reported for electrochemical biosensors. This paper provides a review and analysis of CMOS electrochemical instrumentation circuits. First, important concepts in electrochemical sensing are presented from an instrumentation point of view. Then, electrochemical instrumentation circuits are organized into functional classes, and reported CMOS circuits are reviewed and analyzed to illuminate design options and performance tradeoffs. Finally, recent trends and challenges toward on-CMOS sensor integration that could enable highly miniaturized electrochemical biosensor microsystems are discussed. The information in the paper can guide next generation electrochemical sensor design.

  13. CMOS Electrochemical Instrumentation for Biosensor Microsystems: A Review

    PubMed Central

    Li, Haitao; Liu, Xiaowen; Li, Lin; Mu, Xiaoyi; Genov, Roman; Mason, Andrew J.

    2016-01-01

    Modern biosensors play a critical role in healthcare and have a quickly growing commercial market. Compared to traditional optical-based sensing, electrochemical biosensors are attractive due to superior performance in response time, cost, complexity and potential for miniaturization. To address the shortcomings of traditional benchtop electrochemical instruments, in recent years, many complementary metal oxide semiconductor (CMOS) instrumentation circuits have been reported for electrochemical biosensors. This paper provides a review and analysis of CMOS electrochemical instrumentation circuits. First, important concepts in electrochemical sensing are presented from an instrumentation point of view. Then, electrochemical instrumentation circuits are organized into functional classes, and reported CMOS circuits are reviewed and analyzed to illuminate design options and performance tradeoffs. Finally, recent trends and challenges toward on-CMOS sensor integration that could enable highly miniaturized electrochemical biosensor microsystems are discussed. The information in the paper can guide next generation electrochemical sensor design. PMID:28042860

  14. Electrochemical supercapacitors

    DOEpatents

    Rudge, Andrew J.; Ferraris, John P.; Gottesfeld, Shimshon

    1996-01-01

    A new class of electrochemical capacitors provides in its charged state a positive electrode including an active material of a p-doped material and a negative electrode including an active material of an n-doped conducting polymer, where the p-doped and n-doped materials are separated by an electrolyte. In a preferred embodiment, the positive and negative electrode active materials are selected from conducting polymers consisting of polythiophene, polymers having an aryl group attached in the 3-position, polymers having aryl and alkyl groups independently attached in the 3- and 4-positions, and polymers synthesized from bridged dimers having polythiophene as the backbone. A preferred electrolyte is a tetraalykyl ammonium salt, such as tetramethylammonium trifluoromethane sulphonate (TMATFMS), that provides small ions that are mobile through the active material, is soluble in acetonitrile, and can be used in a variety of capacitor configurations.

  15. Contribution to the knowledge of nickel hydroxide electrodes. 5. Analysis and electrochemical behavior of cadmium nickel hydroxides

    NASA Technical Reports Server (NTRS)

    Bode, H.; Dennstedt, W.

    1981-01-01

    Electrochemical experiments performed at sintered and bulk electrodes show that beta nickel hydroxide contains an electrochemically inactive proportion of cadmium hydroxide of up to 10%. The electrochemically ineffective cadmium hydroxide is homogeneously dissolved in beta nickel hydroxide.

  16. Electrochemical incineration of wastes

    NASA Technical Reports Server (NTRS)

    Kaba, L.; Hitchens, G. D.; Bockris, J. O'M.

    1989-01-01

    A low temperature electrolysis process has been developed for the treatment of solid waste material and urine. Experiments are described in which organic materials are oxidized directly at the surface of an electrode. Also, hypochlorite is generated electrochemically from chloride component of urine. Hypochlorite can act as a strong oxidizing agent in solution. The oxidation takes place at 30-60 C and the gaseous products from the anodic reaction are carbon dioxide, nitrogen, oxygen. Hydrogen is formed at the cathode. Carbon monoxide, and nitrogen oxides and methane were not detected in the off gases. Chlorine was evolved at the anode in relatively low amounts.

  17. Electrochemical Deposition Of Conductive Copolymers

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesan; Distefano, Salvador; Liang, Ranty H.

    1991-01-01

    Experiments show electrically conductive films are deposited on glassy carbon or indium tin oxide substrates by electrochemical polymerization of N-{(3-trimethoxy silyl) propyl} pyrrole or copolymerization with pyrrole. Copolymers of monomer I and pyrrole exhibit desired electrical conductivity as well as desired adhesion and other mechanical properties. When fully developed, new copolymerization process useful in making surface films of selectable conductivity.

  18. Limitations of Focussing on Homophobic, Biphobic and Transphobic "Bullying" to Understand and Address LGBT Young People's Experiences within and beyond School

    ERIC Educational Resources Information Center

    Formby, Eleanor

    2015-01-01

    This paper presents new empirical data that highlight how a focus on "bullying" is too limited and narrow when thinking about homophobia, biphobia and transphobia that young people may experience. The paper draws on two recent studies with young lesbian, gay, bisexual and trans participants, which each identified issues and experiences…

  19. Can pictorial warning labels on cigarette packages address smoking-related health disparities?: Field experiments in Mexico to assess warning label content

    PubMed Central

    Thrasher, James F.; Arillo-Santillán, Edna; Villalobos, Victor; Pérez-Hernández, Rosaura; Hammond, David; Carter, Jarvis; Sebrié, Ernesto; Sansores, Raul; Regalado-Piñeda, Justino

    2012-01-01

    Objective This study aimed to determine the most effective content of pictorial health warning labels (HWLs) and whether educational attainment moderates these effects. Methods Field experiments were conducted with 529 adult smokers and 530 young adults (258 nonsmokers; 271 smokers), wherein participants reported responses to different HWLs printed on cigarette packages. One experiment involved manipulating textual form (testimonial narrative vs didactic) and the other involved manipulating imagery type (diseased organs vs human suffering). Results Tests of mean ratings and rankings indicated that HWLs with didactic textual forms had equivalent or significantly higher credibility, relevance, and impact than HWLs with testimonial forms. Results from mixed-effects models confirmed these results. However, responses differed by participant educational attainment: didactic forms were consistently rated higher than testimonials among participants with higher education, whereas the difference between didactic and testimonial narrative forms was weaker or not statistically significant among participants with lower education. In the second experiment, with textual content held constant, greater credibility, relevance and impact was found for graphic imagery of diseased organs than imagery of human suffering. Conclusions Pictorial HWLs with didactic textual forms appear to work better than with testimonial narratives. Future research should determine which pictorial HWL content has the greatest real-world impact among consumers from disadvantaged groups, including assessment of how HWL content should change to maintain its impact as tobacco control environments strengthen and consumer awareness of smoking-related risks increases. PMID:22350859

  20. Addressing the silence in the noise: how abortion support talklines meet some women's needs for non-political discussion of their experiences.

    PubMed

    Kimport, Katrina; Perrucci, Alissa; Weitz, Tracy A

    2012-01-01

    Abortion is a frequent topic in political discourse, but few opportunities are available for women to discuss their complex emotions and experiences concerning abortion. Popular belief holds that many women need "counseling" about their decision to have an abortion, but little systematic after-abortion emotional care is available. The authors of this study conducted semi-structured interviews (N = 7) and focus groups (N = 2; 13 participants) with staff members and volunteer counselors at four abortion support talklines between February 2009 and March 2010 for their insights into the post-abortion needs of callers. The authors found evidence that some women needed a space devoid of politics for processing their experience and emotions over time. Talklines begin to meet these needs, especially the episodic processing needs of women experiencing emotional difficulty at any time after an abortion. However, some mental health needs are still unmet, including those among women experiencing emotional difficulty due to preexisting conditions co-occurring with, but not caused by, the abortion. The authors of this study call for integrating after-abortion emotional support more fully into the work of abortion provision and women's mental health advocates. The authors warn against using these findings to support legal mandates for post-abortion support, highlighting the negative consequences of such mandates in the pre-abortion arena.

  1. Microfluidic electrochemical reactors

    DOEpatents

    Nuzzo, Ralph G [Champaign, IL; Mitrovski, Svetlana M [Urbana, IL

    2011-03-22

    A microfluidic electrochemical reactor includes an electrode and one or more microfluidic channels on the electrode, where the microfluidic channels are covered with a membrane containing a gas permeable polymer. The distance between the electrode and the membrane is less than 500 micrometers. The microfluidic electrochemical reactor can provide for increased reaction rates in electrochemical reactions using a gaseous reactant, as compared to conventional electrochemical cells. Microfluidic electrochemical reactors can be incorporated into devices for applications such as fuel cells, electrochemical analysis, microfluidic actuation, pH gradient formation.

  2. Every Other Day. Keynote Address.

    ERIC Educational Resources Information Center

    Tiller, Tom

    Schools need to be reoriented and restructured so that what is taught and learned, and the way in which it is taught and learned, are better integrated with young people's real-world experiences. Many indicators suggest that the meaningful aspects of school have been lost in the encounter with modern times. The title of this address--"Every…

  3. A Model Approach to the Electrochemical Cell: An Inquiry Activity

    ERIC Educational Resources Information Center

    Cullen, Deanna M.; Pentecost, Thomas C.

    2011-01-01

    In an attempt to address some student misconceptions in electrochemistry, this guided-inquiry laboratory was devised to give students an opportunity to use a manipulative that simulates the particulate-level activity within an electrochemical cell, in addition to using an actual electrochemical cell. Students are led through a review of expected…

  4. High Power Electrochemical Capacitors

    DTIC Science & Technology

    2012-03-23

    electrochemical properties of vanadium oxide aerogels prepared by a freeze-drying process. Journal of the Electrochemical Society, 2004. 151(5): p...Electrochemical Society, 2002. 149(1): p. A26-A30. 12. Rolison, D.R. and B. Dunn, Electrically conductive oxide aerogels : new materials in...surface area vanadium oxide aerogels . Electrochemical and Solid-State Letters, 2000. 3(10): p. 457-459. 14. Shembel, E., et al., Synthesis, investigation

  5. Electrochemical hydrogen Storage Systems

    SciTech Connect

    Dr. Digby Macdonald

    2010-08-09

    As the global need for energy increases, scientists and engineers have found a possible solution by using hydrogen to power our world. Although hydrogen can be combusted as a fuel, it is considered an energy carrier for use in fuel cells wherein it is consumed (oxidized) without the production of greenhouse gases and produces electrical energy with high efficiency. Chemical storage of hydrogen involves release of hydrogen in a controlled manner from materials in which the hydrogen is covalently bound. Sodium borohydride and aminoborane are two materials given consideration as chemical hydrogen storage materials by the US Department of Energy. A very significant barrier to adoption of these materials as hydrogen carriers is their regeneration from 'spent fuel,' i.e., the material remaining after discharge of hydrogen. The U.S. Department of Energy (DOE) formed a Center of Excellence for Chemical Hydrogen Storage, and this work stems from that project. The DOE has identified boron hydrides as being the main compounds of interest as hydrogen storage materials. The various boron hydrides are then oxidized to release their hydrogen, thereby forming a 'spent fuel' in the form of a lower boron hydride or even a boron oxide. The ultimate goal of this project is to take the oxidized boron hydrides as the spent fuel and hydrogenate them back to their original form so they can be used again as a fuel. Thus this research is essentially a boron hydride recycling project. In this report, research directed at regeneration of sodium borohydride and aminoborane is described. For sodium borohydride, electrochemical reduction of boric acid and sodium metaborate (representing spent fuel) in alkaline, aqueous solution has been investigated. Similarly to literature reports (primarily patents), a variety of cathode materials were tried in these experiments. Additionally, approaches directed at overcoming electrostatic repulsion of borate anion from the cathode, not described in the

  6. Addressing Ozone Layer Depletion

    EPA Pesticide Factsheets

    Access information on EPA's efforts to address ozone layer depletion through regulations, collaborations with stakeholders, international treaties, partnerships with the private sector, and enforcement actions under Title VI of the Clean Air Act.

  7. Development of spiropyran-based electrochemical sensor via simultaneous photochemical and target-activatable electron transfer.

    PubMed

    Tao, Jia; Li, Yinhui; Zhao, Peng; Li, Jishan; Duan, Yu; Zhao, Wenjie; Yang, Ronghua

    2014-12-15

    In traditional electrochemical sensors, the electrochemical signal transduction of the redox-active material is usually controlled by the analytical target. Due to non-specific interaction between the redox mediator and the target, false signal by single stimulus may not be avoided. To address this issue, we have developed a new electrochemical sensor that uses a functional spiropyran, an important class of photo and thermochromic compounds, as both recognition receptor and latent redox mediator, to realize simultaneous photochemical and target-modulated electron transfer. As a proof of principle, β-galactosidase was chosen as a model target. The new synthesized spiropyran probe, SP-β-gal, undergoes reversibly structural isomerization to form merocyanine under UV light irradiation. After the glycosidic bond being cleaved by β-galactosidase, the opened merocyanine of SP-β-gal forms redox-active 2-(2.5-dihydroxystyryl)-1.3.3-trimethyl-3H-indolium, and thus produces a pair of reversible redox current peaks under the electrochemical scanning. To amplify the detection signal, SP-β-gal was self-assembled with single-walled carbon nanotubes (SWCNTs) on the surface of glass carbon electrode. Kinetics experiments confirm that the probe is an ideal candidate for the determination of different concentrations of β-galactosidase digestion kinetics. Further, the SP-β-gal/SWCNTs-modified electrode is chemically stable in complex biological fluids. It was successfully applied to monitor β-galactosidase activity in the 10% calf thymus. This work represents not only a significant step forward in the further development of low-dimensional carbon nanomaterials/small organic molecular probes-based electrochemical biosensors, but also a new platform which may be extended to the assay of other enzyme such as β-D-glycosidase and so on by translating the biorecognition into electrochemical signal responses.

  8. Electrochemical methane sensor

    DOEpatents

    Zaromb, S.; Otagawa, T.; Stetter, J.R.

    1984-08-27

    A method and instrument including an electrochemical cell for the detection and measurement of methane in a gas by the oxidation of methane electrochemically at a working electrode in a nonaqueous electrolyte at a voltage about 1.4 volts vs R.H.E. (the reversible hydrogen electrode potential in the same electrolyte), and the measurement of the electrical signal resulting from the electrochemical oxidation.

  9. Addressable electrode array device with IDA electrodes for high-throughput detection.

    PubMed

    Ino, Kosuke; Saito, Wataru; Koide, Masahiro; Umemura, Taizo; Shiku, Hitoshi; Matsue, Tomokazu

    2011-02-07

    An electrochemical device is proposed for high-throughput electrochemical detection that consists of 32 row and 32 column electrodes on a single glass substrate. The row and column electrodes are connected to interdigitated array (IDA) electrodes to form 1024 (32 × 32) addressable sensor points in the device. Electrochemical responses from each of the 1024 sensors were successfully acquired on the device within 1 min using redox cycling at individual IDA electrodes, which ensures application of the device to comprehensive, high-throughput electrochemical detection for enzyme-linked immunosorbent assay (ELISA), reporter gene assay for monitoring gene expressions, and DNA analysis.

  10. Materials development and electrochemical characterization of polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Wang, Xin

    In this thesis, the materials development and mechanism characterizations of polymer electrolyte fuel cells (PEFCs) are addressed. This work starts with a new preparation technique for a modified electrode structure containing two carbon support materials. The resulted catalyzed electrode, which exhibits good materials properties, demonstrates an improved kinetics in the oxygen reduction reaction (ORR). A new electrocatalyst synthesis procedure utilizing an amphiphilic surfactant to stabilize the nanophase catalyst particles is proposed to fabricate the Pt and Pt-Ru electrocatalysts supported on carbon powders. Physicochemical and electrochemical characterizations of this electrocatalyst show that the nanmeter-scale, well-dispersed catalyst with a high catalytic activity can be obtained. In addition to developing the electrocatalytic materials, an electrochemical impedance based study, aiming to achieve a better understanding of the H 2/CO and methanol oxidation mechanism, is carried out. Unlike the equivalent circuit fitting model frequently used in the fuel cell community, a mathematical simulation tool, utilizing the impedance theory and the reaction kinetics, is developed. This model not only successfully predicts the effects of applied potentials to the impedance but also captures most of the impedance characteristics found in the experiments. In particular, the occurrence of the "pseudo inductive" behavior observed both in the experiments and simulations can be used as an effective criterion for the onset of surface CO oxidation. It is believed that the simulation strategy employed in this study can be utilized to assist the materials design of electrocatalysts with improved CO tolerance and high electrocatalytic activity.

  11. Addressing Social Issues.

    ERIC Educational Resources Information Center

    Schoebel, Susan

    1991-01-01

    Maintains that advertising can help people become more aware of social responsibilities. Describes a successful nationwide newspaper advertising competition for college students in which ads address social issues such as literacy, drugs, teen suicide, and teen pregnancy. Notes how the ads have helped grassroots programs throughout the United…

  12. Invitational Addresses, 1965.

    ERIC Educational Resources Information Center

    Gates, Arthur I.; And Others

    The full texts of invitational addresses given at the 1965 International Reading Association (IRA) Convention in Detroit, Michigan, by six recipients of IRA citation awards are presented. Gates suggests steps IRA should take to revive and redirect reading research. McCallister discusses the implications of the changing and expanding vocabulary of…

  13. States Address Achievement Gaps.

    ERIC Educational Resources Information Center

    Christie, Kathy

    2002-01-01

    Summarizes 2 state initiatives to address the achievement gap: North Carolina's report by the Advisory Commission on Raising Achievement and Closing Gaps, containing an 11-point strategy, and Kentucky's legislation putting in place 10 specific processes. The North Carolina report is available at www.dpi.state.nc.us.closingthegap; Kentucky's…

  14. Addressing Sexual Harassment

    ERIC Educational Resources Information Center

    Young, Ellie L.; Ashbaker, Betty Y.

    2008-01-01

    This article discusses ways on how to address the problem of sexual harassment in schools. Sexual harassment--simply defined as any unwanted and unwelcome sexual behavior--is a sensitive topic. Merely providing students, parents, and staff members with information about the school's sexual harassment policy is insufficient; schools must take…

  15. Electrochemical incineration of wastes

    NASA Astrophysics Data System (ADS)

    Bhardwaj, R. C.; Sharma, D. K.; Bockris, J. Om.

    1990-08-01

    The novel technology of waste removal in space vehicles by electrochemical methods is presented to convert wastes into chemicals that can be eventually recycled. The important consideration for waste oxidation is to select a right kind of electrode (anode) material that should be stable under anodic conditions and also a poor electrocatalyst for oxygen and chlorine evolution. On the basis of long term electrolysis experiments on seven different electrodes and on the basis of total organic carbon reduced, two best electrodes were identified. The effect of redox ions on the electrolyte was studied. Though most of the experiments were done in mixtures of urine and waste, the experiments with redox couples involved 2.5 M sulfuric acid in order to avoid the precipitation of redox ions by urea. Two methods for long term electrolysis of waste were investigated: (1) the oxidation on Pt and lead dioxide electrodes using the galvanostatic methods; and (2) potentiostatic method on other electrodes. The advantage of the first method is the faster rate of oxidation. The chlorine evolution in the second method is ten times less then in the first. The accomplished research has shown that urine/feces mixtures can be oxidized to carbon dioxide and water, but current densities are low and must be improved. The perovskite and Ti4O7 coated with RuO2 are the best electrode materials found. Recent experiment with the redox agent improves the current density, however, sulphuric acid is required to keep the redox agent in solution to enhance oxidation effectively. It is desirable to reduce the use of acid and/or find substitutes.

  16. Electrochemical incineration of wastes

    NASA Technical Reports Server (NTRS)

    Bhardwaj, R. C.; Sharma, D. K.; Bockris, J. OM.

    1990-01-01

    The novel technology of waste removal in space vehicles by electrochemical methods is presented to convert wastes into chemicals that can be eventually recycled. The important consideration for waste oxidation is to select a right kind of electrode (anode) material that should be stable under anodic conditions and also a poor electrocatalyst for oxygen and chlorine evolution. On the basis of long term electrolysis experiments on seven different electrodes and on the basis of total organic carbon reduced, two best electrodes were identified. The effect of redox ions on the electrolyte was studied. Though most of the experiments were done in mixtures of urine and waste, the experiments with redox couples involved 2.5 M sulfuric acid in order to avoid the precipitation of redox ions by urea. Two methods for long term electrolysis of waste were investigated: (1) the oxidation on Pt and lead dioxide electrodes using the galvanostatic methods; and (2) potentiostatic method on other electrodes. The advantage of the first method is the faster rate of oxidation. The chlorine evolution in the second method is ten times less then in the first. The accomplished research has shown that urine/feces mixtures can be oxidized to carbon dioxide and water, but current densities are low and must be improved. The perovskite and Ti4O7 coated with RuO2 are the best electrode materials found. Recent experiment with the redox agent improves the current density, however, sulphuric acid is required to keep the redox agent in solution to enhance oxidation effectively. It is desirable to reduce the use of acid and/or find substitutes.

  17. Electrochemical oxidation of cholesterol

    PubMed Central

    2015-01-01

    Summary Indirect cholesterol electrochemical oxidation in the presence of various mediators leads to electrophilic addition to the double bond, oxidation at the allylic position, oxidation of the hydroxy group, or functionalization of the side chain. Recent studies have proven that direct electrochemical oxidation of cholesterol is also possible and affords different products depending on the reaction conditions. PMID:25977713

  18. Electrochemical cell stack assembly

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2010-06-22

    Multiple stacks of tubular electrochemical cells having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films arranged in parallel on stamped conductive interconnect sheets or ferrules. The stack allows one or more electrochemical cell to malfunction without disabling the entire stack. Stack efficiency is enhanced through simplified gas manifolding, gas recycling, reduced operating temperature and improved heat distribution.

  19. Electrochemical apparatus comprising modified disposable rectangular cuvette

    DOEpatents

    Dattelbaum, Andrew M; Gupta, Gautam; Morris, David E

    2013-09-10

    Electrochemical apparatus includes a disposable rectangular cuvette modified with at least one hole through a side and/or the bottom. Apparatus may include more than one cuvette, which in practice is a disposable rectangular glass or plastic cuvette modified by drilling the hole(s) through. The apparatus include two plates and some means of fastening one plate to the other. The apparatus may be interfaced with a fiber optic or microscope objective, and a spectrometer for spectroscopic studies. The apparatus are suitable for a variety of electrochemical experiments, including surface electrochemistry, bulk electrolysis, and flow cell experiments.

  20. Content Addressable Memory Project

    DTIC Science & Technology

    1990-11-01

    The Content Addressable M1-emory Project consists of the development of several experimental software systems on an AMT Distributed Array Processor...searching (database) compiler algorithms memory management other systems software) Linear C is an unlovely hybrid language which imports the CAM...memory from AMT’s operating system for the DAP; how- ever, other than this limitation, the memory management routines work exactly as their C counterparts

  1. Electrochemical thermodynamic measurement system

    DOEpatents

    Reynier, Yvan; Yazami, Rachid; Fultz, Brent T.

    2009-09-29

    The present invention provides systems and methods for accurately characterizing thermodynamic and materials properties of electrodes and electrochemical energy storage and conversion systems. Systems and methods of the present invention are configured for simultaneously collecting a suite of measurements characterizing a plurality of interconnected electrochemical and thermodynamic parameters relating to the electrode reaction state of advancement, voltage and temperature. Enhanced sensitivity provided by the present methods and systems combined with measurement conditions that reflect thermodynamically stabilized electrode conditions allow very accurate measurement of thermodynamic parameters, including state functions such as the Gibbs free energy, enthalpy and entropy of electrode/electrochemical cell reactions, that enable prediction of important performance attributes of electrode materials and electrochemical systems, such as the energy, power density, current rate and the cycle life of an electrochemical cell.

  2. Planar electrochemical device assembly

    DOEpatents

    Jacobson; Craig P. , Visco; Steven J. , De Jonghe; Lutgard C.

    2010-11-09

    A pre-fabricated electrochemical device having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films is bonded to a porous electrically conductive support. A second porous electrically conductive support may be bonded to a counter electrode of the electrochemical device. Multiple electrochemical devices may be bonded in parallel to a single porous support, such as a perforated sheet to provide a planar array. Planar arrays may be arranged in a stacked interconnected array. A method of making a supported electrochemical device is disclosed wherein the method includes a step of bonding a pre-fabricated electrochemical device layer to an existing porous metal or porous metal alloy layer.

  3. Planar electrochemical device assembly

    DOEpatents

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    2007-06-19

    A pre-fabricated electrochemical device having a dense electrolyte disposed between an anode and a cathode preferably deposited as thin films is bonded to a porous electrically conductive support. A second porous electrically conductive support may be bonded to a counter electrode of the electrochemical device. Multiple electrochemical devices may be bonded in parallel to a single porous support, such as a perforated sheet to provide a planar array. Planar arrays may be arranged in a stacked interconnected array. A method of making a supported electrochemical device is disclosed wherein the method includes a step of bonding a pre-fabricated electrochemical device layer to an existing porous metal or porous metal alloy layer.

  4. Electrochemical biosensing strategies for DNA methylation analysis.

    PubMed

    Hossain, Tanvir; Mahmudunnabi, Golam; Masud, Mostafa Kamal; Islam, Md Nazmul; Ooi, Lezanne; Konstantinov, Konstantin; Hossain, Md Shahriar Al; Martinac, Boris; Alici, Gursel; Nguyen, Nam-Trung; Shiddiky, Muhammad J A

    2017-02-17

    DNA methylation is one of the key epigenetic modifications of DNA that results from the enzymatic addition of a methyl group at the fifth carbon of the cytosine base. It plays a crucial role in cellular development, genomic stability and gene expression. Aberrant DNA methylation is responsible for the pathogenesis of many diseases including cancers. Over the past several decades, many methodologies have been developed to detect DNA methylation. These methodologies range from classical molecular biology and optical approaches, such as bisulfite sequencing, microarrays, quantitative real-time PCR, colorimetry, Raman spectroscopy to the more recent electrochemical approaches. Among these, electrochemical approaches offer sensitive, simple, specific, rapid, and cost-effective analysis of DNA methylation. Additionally, electrochemical methods are highly amenable to miniaturization and possess the potential to be multiplexed. In recent years, several reviews have provided information on the detection strategies of DNA methylation. However, to date, there is no comprehensive evaluation of electrochemical DNA methylation detection strategies. Herein, we address the recent developments of electrochemical DNA methylation detection approaches. Furthermore, we highlight the major technical and biological challenges involved in these strategies and provide suggestions for the future direction of this important field.

  5. Bioreactors Addressing Diabetes Mellitus

    PubMed Central

    Minteer, Danielle M.; Gerlach, Jorg C.

    2014-01-01

    The concept of bioreactors in biochemical engineering is a well-established process; however, the idea of applying bioreactor technology to biomedical and tissue engineering issues is relatively novel and has been rapidly accepted as a culture model. Tissue engineers have developed and adapted various types of bioreactors in which to culture many different cell types and therapies addressing several diseases, including diabetes mellitus types 1 and 2. With a rising world of bioreactor development and an ever increasing diagnosis rate of diabetes, this review aims to highlight bioreactor history and emerging bioreactor technologies used for diabetes-related cell culture and therapies. PMID:25160666

  6. Bioreactors addressing diabetes mellitus.

    PubMed

    Minteer, Danielle M; Gerlach, Jorg C; Marra, Kacey G

    2014-11-01

    The concept of bioreactors in biochemical engineering is a well-established process; however, the idea of applying bioreactor technology to biomedical and tissue engineering issues is relatively novel and has been rapidly accepted as a culture model. Tissue engineers have developed and adapted various types of bioreactors in which to culture many different cell types and therapies addressing several diseases, including diabetes mellitus types 1 and 2. With a rising world of bioreactor development and an ever increasing diagnosis rate of diabetes, this review aims to highlight bioreactor history and emerging bioreactor technologies used for diabetes-related cell culture and therapies.

  7. Content addressable memory project

    NASA Technical Reports Server (NTRS)

    Hall, J. Storrs; Levy, Saul; Smith, Donald E.; Miyake, Keith M.

    1992-01-01

    A parameterized version of the tree processor was designed and tested (by simulation). The leaf processor design is 90 percent complete. We expect to complete and test a combination of tree and leaf cell designs in the next period. Work is proceeding on algorithms for the computer aided manufacturing (CAM), and once the design is complete we will begin simulating algorithms for large problems. The following topics are covered: (1) the practical implementation of content addressable memory; (2) design of a LEAF cell for the Rutgers CAM architecture; (3) a circuit design tool user's manual; and (4) design and analysis of efficient hierarchical interconnection networks.

  8. Addressing Environmental Health Inequalities

    PubMed Central

    Gouveia, Nelson

    2016-01-01

    Environmental health inequalities refer to health hazards disproportionately or unfairly distributed among the most vulnerable social groups, which are generally the most discriminated, poor populations and minorities affected by environmental risks. Although it has been known for a long time that health and disease are socially determined, only recently has this idea been incorporated into the conceptual and practical framework for the formulation of policies and strategies regarding health. In this Special Issue of the International Journal of Environmental Research and Public Health (IJERPH), “Addressing Environmental Health Inequalities—Proceedings from the ISEE Conference 2015”, we incorporate nine papers that were presented at the 27th Conference of the International Society for Environmental Epidemiology (ISEE), held in Sao Paulo, Brazil, in 2015. This small collection of articles provides a brief overview of the different aspects of this topic. Addressing environmental health inequalities is important for the transformation of our reality and for changing the actual development model towards more just, democratic, and sustainable societies driven by another form of relationship between nature, economy, science, and politics. PMID:27618906

  9. Electrochemical force microscopy

    DOEpatents

    Kalinin, Sergei V.; Jesse, Stephen; Collins, Liam F.; Rodriguez, Brian J.

    2017-01-10

    A system and method for electrochemical force microscopy are provided. The system and method are based on a multidimensional detection scheme that is sensitive to forces experienced by a biased electrode in a solution. The multidimensional approach allows separation of fast processes, such as double layer charging, and charge relaxation, and slow processes, such as diffusion and faradaic reactions, as well as capturing the bias dependence of the response. The time-resolved and bias measurements can also allow probing both linear (small bias range) and non-linear (large bias range) electrochemical regimes and potentially the de-convolution of charge dynamics and diffusion processes from steric effects and electrochemical reactivity.

  10. Electrode for electrochemical cell

    DOEpatents

    Kaun, T.D.; Nelson, P.A.; Miller, W.E.

    1980-05-09

    An electrode structure for a secondary electrochemical cell includes an outer enclosure defining a compartment containing electrochemical active material. The enclosure includes a rigid electrically conductive metal sheet with perforated openings over major side surfaces. The enclosure can be assembled as first and second trays each with a rigid sheet of perforated electrically conductive metal at major side surfaces and normally extending flanges at parametric margins. The trays can be pressed together with moldable active material between the two to form an expandable electrode. A plurality of positive and negative electrodes thus formed are arranged in an alternating array with porous frangible interelectrode separators within the housing of the secondary electrochemical cell.

  11. Electrode for electrochemical cell

    DOEpatents

    Kaun, Thomas D.; Nelson, Paul A.; Miller, William E.

    1981-01-01

    An electrode structure for a secondary electrochemical cell includes an outer enclosure defining a compartment containing electrochemical active material. The enclosure includes a rigid electrically conductive metal sheet with perforated openings over major side surfaces. The enclosure can be assembled as first and second trays each with a rigid sheet of perforated electrically conductive metal at major side surfaces and normally extending flanges at parametric margins. The trays can be pressed together with moldable active material between the two to form an expandable electrode. A plurality of positive and negative electrodes thus formed are arranged in an alternating array with porous frangible interelectrode separators within the housing of the secondary electrochemical cell.

  12. Electrochemical Hydrogen Compressor

    SciTech Connect

    David P. Bloomfield; Brian S. MacKenzie

    2006-05-01

    The Electrochemical Hydrogen Compressor EHC was evaluated against DOE applications for compressing hydrogen at automobile filling stations, in future hydrogen pipelines and as a commercial replacement for conventional diaphragm hydrogen compressors. It was also evaluated as a modular replacement for the compressors used in petrochemical refineries. If the EHC can be made inexpensive, reliable and long lived then it can satisfy all these applications save pipelines where the requirements for platinum catalyst exceeds the annual world production. The research performed did not completely investigate Molybdenum as a hydrogen anode or cathode, it did show that photoetched 316 stainless steel is inadequate for an EHC. It also showed that: molybdenum bipolar plates, photochemical etching processes, and Gortex Teflon seals are too costly for a commercial EHC. The use of carbon paper in combination with a perforated thin metal electrode demonstrated adequate anode support strength, but is suspect in promoting galvanic corrosion. The nature of the corrosion mechanisms are not well understood, but locally high potentials within the unit cell package are probably involved. The program produced a design with an extraordinary high cell pitch, and a very low part count. This is one of the promising aspects of the redesigned EHC. The development and successful demonstration of the hydraulic cathode is also important. The problem of corrosion resistant metal bipolar plates is vital to the development of an inexpensive, commercial PEM fuel cell. Our research suggests that there is more to the corrosion process in fuel cells and electrochemical compressors than simple, steady state, galvanic stability. It is an important area for scientific investigation. The experiments and analysis conducted lead to several recommended future research directions. First, we need a better understanding of the corrosion mechanisms involved. The diagnosis of experimental cells with titration to

  13. Content addressable memory project

    NASA Technical Reports Server (NTRS)

    Hall, Josh; Levy, Saul; Smith, D.; Wei, S.; Miyake, K.; Murdocca, M.

    1991-01-01

    The progress on the Rutgers CAM (Content Addressable Memory) Project is described. The overall design of the system is completed at the architectural level and described. The machine is composed of two kinds of cells: (1) the CAM cells which include both memory and processor, and support local processing within each cell; and (2) the tree cells, which have smaller instruction set, and provide global processing over the CAM cells. A parameterized design of the basic CAM cell is completed. Progress was made on the final specification of the CPS. The machine architecture was driven by the design of algorithms whose requirements are reflected in the resulted instruction set(s). A few of these algorithms are described.

  14. Science and Technology Text Mining: Electrochemical Power

    DTIC Science & Technology

    2003-07-14

    literature, or company proprietary technology literature. It does not include technical reports or books or patents on Electrochemical Power . It covers a...Capacitors; Energy Production; Power Production; Energy Conversion; Energy Storage; Citation Analysis; Scientometrics; Military Requirements REPORT ...control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 14-07-2003 2. REPORT TYPE Technical 3. DATES COVERED (FROM

  15. Electrochemical processing of solid waste

    NASA Technical Reports Server (NTRS)

    Bockris, J. OM.; Hitchens, G. D.; Kaba, L.

    1988-01-01

    The investigation into electrolysis as a means of waste treatment and recycling on manned space missions is described. The electrochemical reactions of an artificial fecal waste mixture was examined. Waste electrolysis experiments were performed in a single compartment reactor, on platinum electrodes, to determine conditions likely to maximize the efficiency of oxidation of fecal waste material to CO2. The maximum current efficiencies for artificial fecal waste electrolysis to CO2 was found to be around 50 percent in the test apparatus. Experiments involving fecal waste oxidation on platinum indicates that electrodes with a higher overvoltage for oxygen evolution such as lead dioxide will give a larger effective potential range for organic oxidation reactions. An electrochemical packed column reactor was constructed with lead dioxide as electrode material. Preliminary experiments were performed using a packed-bed reactor and continuous flow techniques showing this system may be effective in complete oxidation of fecal material. The addition of redox mediator Ce(3+)/Ce(4+) enhances the oxidation process of biomass components. Scientific literature relevant to biomass and fecal waste electrolysis were reviewed.

  16. Addressing Test Anxiety

    ERIC Educational Resources Information Center

    Salend, Spencer J.

    2011-01-01

    Research suggests that between 25% to 40% of students experience test anxiety, with students with disabilities and those from culturally and linguistically diverse backgrounds having higher prevalence rates. Since test anxiety impacts student well-being and the validity of the important educational decisions based on testing data, this article…

  17. Electrochemical Sensors: Functionalized Silica

    SciTech Connect

    Fryxell, Glen E.; Lin, Yuehe; Yantasee, Wassana

    2009-03-24

    This chapter summarizes recent devellopment of electrochemical sensors based on functionlized mesoporous silica materials. The nanomatrials based sensors have been developed for sensitive and selective enrironmental detection of toxic heavy metal and uranium ions.

  18. Advanced Electrochemical Waste Forms

    SciTech Connect

    Riley, Brian J.; Crum, Jarrod V.; McCloy, John S.; Matyas, Josef

    2011-12-01

    This is a brief description of PNNL's efforts in FY2011 towards developing advanced electrochemical waste forms. This is a short section that will become part of a larger document being put together by INL.

  19. Electrochemical Analysis of Neurotransmitters

    NASA Astrophysics Data System (ADS)

    Bucher, Elizabeth S.; Wightman, R. Mark

    2015-07-01

    Chemical signaling through the release of neurotransmitters into the extracellular space is the primary means of communication between neurons. More than four decades ago, Ralph Adams and his colleagues realized the utility of electrochemical methods for the study of easily oxidizable neurotransmitters, such as dopamine, norepinephrine, and serotonin and their metabolites. Today, electrochemical techniques are frequently coupled to microelectrodes to enable spatially resolved recordings of rapid neurotransmitter dynamics in a variety of biological preparations spanning from single cells to the intact brain of behaving animals. In this review, we provide a basic overview of the principles underlying constant-potential amperometry and fast-scan cyclic voltammetry, the most commonly employed electrochemical techniques, and the general application of these methods to the study of neurotransmission. We thereafter discuss several recent developments in sensor design and experimental methodology that are challenging the current limitations defining the application of electrochemical methods to neurotransmitter measurements.

  20. ELECTROCHEMICAL DEGRADATION OF POLYCHLOROBIPHENYLS

    EPA Science Inventory

    Granular graphite is an ideal conductive material for electrochemical reduction technology applications in the field. Granular graphite was used to enhance the transfer of chlorinated aliphatic compounds in saturated, low permeability soils by electroosmosis. It was also used to ...

  1. Electrochemical Analysis of Neurotransmitters

    PubMed Central

    Bucher, Elizabeth S.; Wightman, R. Mark

    2016-01-01

    Chemical signaling through the release of neurotransmitters into the extracellular space is the primary means of communication between neurons. More than four decades ago, Ralph Adams and his colleagues realized the utility of electrochemical methods for the study of easily oxidizable neurotransmitters, such as dopamine, norepinephrine, and serotonin and their metabolites. Today, electrochemical techniques are frequently coupled to microelectrodes to enable spatially resolved recordings of rapid neurotransmitter dynamics in a variety of biological preparations spanning from single cells to the intact brain of behaving animals. In this review, we provide a basic overview of the principles underlying constant-potential amperometry and fast-scan cyclic voltammetry, the most commonly employed electrochemical techniques, and the general application of these methods to the study of neurotransmission. We thereafter discuss several recent developments in sensor design and experimental methodology that are challenging the current limitations defining the application of electrochemical methods to neurotransmitter measurements. PMID:25939038

  2. Electrochemical heat engine

    DOEpatents

    Elliott, Guy R. B.; Holley, Charles E.; Houseman, Barton L.; Sibbitt, Jr., Wilmer L.

    1978-01-01

    Electrochemical heat engines produce electrochemical work, and mechanical motion is limited to valve and switching actions as the heat-to-work cycles are performed. The electrochemical cells of said heat engines use molten or solid electrolytes at high temperatures. One or more reactions in the cycle will generate a gas at high temperature which can be condensed at a lower temperature with later return of the condensate to electrochemical cells. Sodium, potassium, and cesium are used as the working gases for high temperature cells (above 600 K) with halogen gases or volatile halides being used at lower temperature. Carbonates and halides are used as molten electrolytes and the solid electrolyte in these melts can also be used as a cell separator.

  3. Electrochemical Analysis of Neurotransmitters.

    PubMed

    Bucher, Elizabeth S; Wightman, R Mark

    2015-01-01

    Chemical signaling through the release of neurotransmitters into the extracellular space is the primary means of communication between neurons. More than four decades ago, Ralph Adams and his colleagues realized the utility of electrochemical methods for the study of easily oxidizable neurotransmitters, such as dopamine, norepinephrine, and serotonin and their metabolites. Today, electrochemical techniques are frequently coupled to microelectrodes to enable spatially resolved recordings of rapid neurotransmitter dynamics in a variety of biological preparations spanning from single cells to the intact brain of behaving animals. In this review, we provide a basic overview of the principles underlying constant-potential amperometry and fast-scan cyclic voltammetry, the most commonly employed electrochemical techniques, and the general application of these methods to the study of neurotransmission. We thereafter discuss several recent developments in sensor design and experimental methodology that are challenging the current limitations defining the application of electrochemical methods to neurotransmitter measurements.

  4. Electrochemical Atomic Layer Processing

    DTIC Science & Technology

    1994-06-25

    where an atomic layer of an element is deposited , or removed, in a surface limited reaction. The potentials used are referred to as underpotentials in...the electrochemical literature. The atomic layer deposition process is referred to as underpotential deposition (UPD). 14. SUBJECT TERMS 15, NUMBER OF...reaction. The potentials used are referred to as underpotentials in the electrochemical literature. The atomic layer deposition process is referred to as

  5. Electrochemical Energy Storage Materials

    DTIC Science & Technology

    2012-07-01

    separated to allow the electrolyte diffusion in an electrochemical cell . Figure 9c shows a zoomed cross-sectional view of the TiO2 coated Ni...Electrochemical half- cells were assembled using the TiO2 coated Ni nanowire arrays (working electrode) and Li foil (counter electrode) separated by two layers... Solar Cells Using Coaxial Electrospinning.” James R. Deneault, Xiaoyin Xiao, Tae-Sik Kang, Joanna S. Wang, Chien M. Wai, Gail J. Brown, Michael F

  6. Solid state electrochemical composite

    DOEpatents

    Visco, Steven J.; Jacobson, Craig P.; DeJonghe, Lutgard C.

    2009-06-30

    Provided is a composite electrochemical device fabricated from highly electronically conductive materials such as metals, metal alloys, or electronically conductive ceramics. The electronic conductivity of the electrode substrate is maximized. The invention allows for an electrode with high electronic conductivity and sufficient catalytic activity to achieve high power density in ionic (electrochemical) devices such as fuel cells and electrolytic gas separation systems including oxygen generation system.

  7. Space Electrochemical Research and Technology

    NASA Technical Reports Server (NTRS)

    Wilson, Richard M. (Compiler)

    1996-01-01

    Individual papers presented at the conference address the following topics: development of a micro-fiber nickel electrode for nickel-hydrogen cell, high performance nickel electrodes for space power application, bending properties of nickel electrodes for nickel-hydrogen batteries, effect of KOH concentration and anions on the performance of a Ni-H2 battery positive plate, advanced dependent pressure vessel nickel hydrogen spacecraft cell and battery design, electrolyte management considerations in modern nickel hydrogen and nickel cadmium cell and battery design, a novel unitized regenerative proton exchange membrane fuel cell, fuel cell systems for first lunar outpost - reactant storage options, the TMI regenerable solid oxide fuel cell, engineering development program of a closed aluminum-oxygen semi-cell system for an unmanned underwater vehicle, SPE OBOGS on-board oxygen generating system, hermetically sealed aluminum electrolytic capacitor, sol-gel technology and advanced electrochemical energy storage materials, development of electrochemical supercapacitors for EMA applications, and high energy density electrolytic capacitor.

  8. Genomagnetic Electrochemical Biosensors

    NASA Astrophysics Data System (ADS)

    Wang, Joseph; Erdem, Arzum

    The use of nucleic acid technologies has significantly improved preparation and diagnostic procedures in life sciences. Nucleic acid layers combined with electrochemical or optical transducers produce a new kind of affinity biosensors as DNA Biosensor for small molecular weight molecules. Electrochemical DNA biosensors are attractive devices for converting the hybridization event into an analytical signal for obtaining sequence-specific information in connection with clinical, environmental or forensic investigations. DNA hybridization biosensors, based on electrochemical transduction of hybridization, couple the high specificity of hybridization reactions with the excellent sensitivity and portability of electrochemical transducers. The main goal in all researches is to design DNA biosensors for preparing a basis for the future DNA microarray system. DNA chip has now become a powerful tool in biological research, however the real clinic assay is still under development. Recently, there has been a great interest to the magnetic beads and/or nanoparticles labelled with metals such as gold, cadmium, silver, etc. for designing of novel electrochemical DNA biosensor approaches resulting in efficient separation. The attractive features of this technology include simple approach, rapid results, multi-analyte detection, low-cost per measurument, stable, and non-hazardous reagents, and reduced waste handling. Some of these new approaches and applications of the electrochemical DNA biosensors based on magnetic beads and its combining with nanoparticles labelled with metals are described and discussed.

  9. Electrochemical control of creep in nanoporous gold

    SciTech Connect

    Ye, Xing-Long; Jin, Hai-Jun

    2013-11-11

    We have investigated the mechanical stability of nanoporous gold (npg) in an electrochemical environment, using in situ dilatometry and compression experiments. It is demonstrated that the gold nano-ligaments creep under the action of surface stress which leads to spontaneous volume contractions in macroscopic npg samples. The creep of npg, under or without external forces, can be controlled electrochemically. The creep rate increases with increasing potential in double-layer potential region, and deceases to almost zero when the gold surface is adsorbed with oxygen. Surprisingly, we also noticed a correlation between creep and surface diffusivity, which links the deformation of nanocrystals to mobility of surface atoms.

  10. [Keynote address: Climate change

    SciTech Connect

    Forrister, D.

    1994-12-31

    Broadly speaking, the climate issue is moving from talk to action both in the United States and internationally. While few nations have adopted strict controls or stiff new taxes, a number of them are developing action plans that are making clear their intention to ramp up activity between now and the year 2000... and beyond. There are sensible, economically efficient strategies to be undertaken in the near term that offer the possibility, in many countries, to avoid more draconian measures. These strategies are by-and-large the same measures that the National Academy of Sciences recommended in a 1991 report called, Policy Implications of Greenhouse Warming. The author thinks the Academy`s most important policy contribution was how it recommended the nations act in the face of uncertain science and high risks--that cost effective measures are adopted as cheap insurance... just as nations insure against other high risk, low certainty possibilities, like catastrophic health insurance, auto insurance, and fire insurance. This insurance theme is still right. First, the author addresses how the international climate change negotiations are beginning to produce insurance measures. Next, the author will discuss some of the key issues to watch in those negotiations that relate to longer-term insurance. And finally, the author will report on progress in the United States on the climate insurance plan--The President`s Climate Action Plan.

  11. Electrochemical Hydrogen Peroxide Generator

    NASA Technical Reports Server (NTRS)

    Tennakoon, Charles L. K.; Singh, Waheguru; Anderson, Kelvin C.

    2010-01-01

    Two-electron reduction of oxygen to produce hydrogen peroxide is a much researched topic. Most of the work has been done in the production of hydrogen peroxide in basic media, in order to address the needs of the pulp and paper industry. However, peroxides under alkaline conditions show poor stabilities and are not useful in disinfection applications. There is a need to design electrocatalysts that are stable and provide good current and energy efficiencies to produce hydrogen peroxide under acidic conditions. The innovation focuses on the in situ generation of hydrogen peroxide using an electrochemical cell having a gas diffusion electrode as the cathode (electrode connected to the negative pole of the power supply) and a platinized titanium anode. The cathode and anode compartments are separated by a readily available cation-exchange membrane (Nafion 117). The anode compartment is fed with deionized water. Generation of oxygen is the anode reaction. Protons from the anode compartment are transferred across the cation-exchange membrane to the cathode compartment by electrostatic attraction towards the negatively charged electrode. The cathode compartment is fed with oxygen. Here, hydrogen peroxide is generated by the reduction of oxygen. Water may also be generated in the cathode. A small amount of water is also transported across the membrane along with hydrated protons transported across the membrane. Generally, each proton is hydrated with 3-5 molecules. The process is unique because hydrogen peroxide is formed as a high-purity aqueous solution. Since there are no hazardous chemicals or liquids used in the process, the disinfection product can be applied directly to water, before entering a water filtration unit to disinfect the incoming water and to prevent the build up of heterotrophic bacteria, for example, in carbon based filters. The competitive advantages of this process are: 1. No consumable chemicals are needed in the process. The only raw materials

  12. ENHANCED ELECTROCHEMICAL PROCESSES IN SUBCRITICAL WATER

    SciTech Connect

    Steven B. Hawthorne

    2000-07-01

    This project involved designing and performing preliminary electrochemical experiments in subcritical water. An electrochemical cell with substantially better performance characteristics than presently available was designed, built, and tested successfully. The electrochemical conductivity of subcritical water increased substantially with temperature, e.g., conductivities increased by a factor of 120 when the temperature was increased from 25 to 250 C. Cyclic voltammograms obtained with platinum and nickel demonstrated that the voltage required to produce hydrogen and oxygen from water can be dropped by a factor of three in subcritical water compared to the voltages required at ambient temperatures. However, no enhancement in the degradation of 1,2-dichlorobenzene and the polychlorinated biphenyl 3,3',4,4'-tetrachlorobiphenyl was observed with applied potential in subcritical water.

  13. Electrochemical Implications of Defects in Carbon Nanotubes

    NASA Astrophysics Data System (ADS)

    Hall, Jonathan Peter

    The electrochemical behavior of carbon nanotubes (CNTs) containing both intrinsic and extrinsically introduced defects has been investigated through the study of bamboo and hollow multi-walled CNT morphologies. The controlled addition of argon, hydrogen, and chlorine ions in addition to atomic hydrogen and magnesium vapor was used for varying the charge and type of extrinsic defects. To quantify changes in the CNTs upon treatment, Raman spectroscopy and electrochemical techniques were employed. It was indicated from Raman spectroscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and chronopotentiometric experiments that the electrochemical response of hollow type CNTs could be tailored more significantly compared to bamboo type CNTs, which have innately high reactive site densities and are less amenable to modification. Total defect density and edge-plane-like defect concentrations monitored through Raman spectroscopy were used to correlate changes in the electrochemical response of the CNT electrodes as a function of treatment. The implementation of CNT electrodes in a prototypical electrolytic capacitor device was then explored and characterized. Dependencies on source current and redox couple concentration were evaluated, as well as changes in the total capacitance as a function of treatment. Cyclability studies were also performed as a function of source current magnitude to evaluate the longevity of the faradaic currents which typically decrease over time in other similar capacitors. This thesis then concludes with an overall summary of the themes and findings of the research presented in this work.

  14. Materials for electrochemical capacitors.

    PubMed

    Simon, Patrice; Gogotsi, Yury

    2008-11-01

    Electrochemical capacitors, also called supercapacitors, store energy using either ion adsorption (electrochemical double layer capacitors) or fast surface redox reactions (pseudo-capacitors). They can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. A notable improvement in performance has been achieved through recent advances in understanding charge storage mechanisms and the development of advanced nanostructured materials. The discovery that ion desolvation occurs in pores smaller than the solvated ions has led to higher capacitance for electrochemical double layer capacitors using carbon electrodes with subnanometre pores, and opened the door to designing high-energy density devices using a variety of electrolytes. Combination of pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries. The use of carbon nanotubes has further advanced micro-electrochemical capacitors, enabling flexible and adaptable devices to be made. Mathematical modelling and simulation will be the key to success in designing tomorrow's high-energy and high-power devices.

  15. Technology Base Research Project for Electrochemical Energy Storage

    NASA Astrophysics Data System (ADS)

    Kinoshita, K.

    1984-05-01

    The establishment of this research base which supports efforts to develop electrochemical technology for electric vehicle and stationary energy storage applications is discussed. The general objective of the technology base research project is to provide advanced electrochemical systems that satisfy stringent performance and economic requirements for electric vehicle and stationary energy storage applications. The specific goal is to identify the most promising electrochemical technologies and transfer them to industry and further development and scale up. General problem areas addressed include: identification of new electrochemical couples for advanced batteries, determination of technical feasibility of the new couples, improvements in battery components and materials, establishment of engineering principles applicable to electrochemical energy storage and conversion, and the assessment of fuel cell technology for transportation applications. Applied research which will lead to superior performance and lower life-cycle cost is emphasized. The TBR project is divided into four major project elements: (1) electrochemical systems research; (2) supporting research; (3) electrochemical processes, and (4) fuel cells for vehicles.

  16. Synchrotron-Based Infrared Microanalysis of Biological Redox Processes under Electrochemical Control

    PubMed Central

    2016-01-01

    We describe a method for addressing redox enzymes adsorbed on a carbon electrode using synchrotron infrared microspectroscopy combined with protein film electrochemistry. Redox enzymes have high turnover frequencies, typically 10–1000 s–1, and therefore, fast experimental triggers are needed in order to study subturnover kinetics and identify the involvement of transient species important to their catalytic mechanism. In an electrochemical experiment, this equates to the use of microelectrodes to lower the electrochemical cell constant and enable changes in potential to be applied very rapidly. We use a biological cofactor, flavin mononucleotide, to demonstrate the power of synchrotron infrared microspectroscopy relative to conventional infrared methods and show that vibrational spectra with good signal-to-noise ratios can be collected for adsorbed species with low surface coverages on microelectrodes with a geometric area of 25 × 25 μm2. We then demonstrate the applicability of synchrotron infrared microspectroscopy to adsorbed proteins by reporting potential-induced changes in the flavin mononucleotide active site of a flavoenzyme. The method we describe will allow time-resolved spectroscopic studies of chemical and structural changes at redox sites within a variety of proteins under precise electrochemical control. PMID:27269716

  17. A Corona Discharge Initiated Electrochemical Electrospray Ionization Technique

    PubMed Central

    Lloyd, John R.; Hess, Sonja

    2009-01-01

    We report here the development of a corona discharge (CD) initiated electrochemical (EC) electrospray ionization (ESI) technique using a standard electrospray ion source. This is a new ionization technique distinct from ESI, electrochemistry inherent to ESI, APCI, and techniques using hydroxyl radicals produced under atmospheric pressure conditions. By maximizing the observable CD at the tip of a stainless steel ESI capillary, efficient electrochemical oxidation of electrochemically active compounds is observed. For electrochemical oxidation to be observed, the ionization potential of the analyte must be lower than Fe. Ferrocene labeled compounds were chosen as the electrochemically active moiety. The electrochemical cell in the ESI source was robust and generated ions with selectivity according to the ionization potential of the analytes and up to zeptomolar sensitivity. Our results indicate that CD initiated electrochemical ionization has the potential to become a powerful technique to increase the dynamic range, sensitivity and selectivity of ESI experiments. Synopsis Using a standard ESI source a corona discharge initiated electrochemical ionization technique was established resulting from the electrochemistry occurring at the CD electrode surface. PMID:19747843

  18. Electrochemical Membrane Incinerator

    SciTech Connect

    Johnson, Dennis C.; Houk, Linda L.; Feng, Jianren

    1998-12-08

    Electrochemical incineration of benzoquinone was evaluated as a model for the mineralization of carbon in toxic aromatic compounds. A Ti or Pt anode was coated with a film of the oxides of Ti, Ru, Sn and Sb. This quaternary metal oxide film was stable; elemental analysis of the electrolyzed solution indicated the concentration of these metal ions to be 3 {micro}g/L or less. The anode showed good reactivity for the electrochemical incineration of benzoquinone. The use of a dissolved salt matrix as the so-called ''supporting electrolyte'' was eliminated in favor of a solid-state electrolyte sandwiched between the anode and cathode.

  19. Engineering electrochemical capacitor applications

    NASA Astrophysics Data System (ADS)

    Miller, John R.

    2016-09-01

    Electrochemical capacitor (EC) applications have broadened tremendously since EC energy storage devices were introduced in 1978. Then typical applications operated below 10 V at power levels below 1 W. Today many EC applications operate at voltages approaching 1000 V at power levels above 100 kW. This paper briefly reviews EC energy storage technology, shows representative applications using EC storage, and describes engineering approaches to design EC storage systems. Comparisons are made among storage systems designed to meet the same application power requirement but using different commercial electrochemical capacitor products.

  20. Electrochemical fabrication of capacitors

    DOEpatents

    Mansour, Azzam N.; Melendres, Carlos A.

    1999-01-01

    A film of nickel oxide is anodically deposited on a graphite sheet held in osition on an electrochemical cell during application of a positive electrode voltage to the graphite sheet while exposed to an electrolytic nickel oxide solution within a volumetrically variable chamber of the cell. An angularly orientated x-ray beam is admitted into the cell for transmission through the deposited nickel oxide film in order to obtain structural information while the film is subject to electrochemical and in-situ x-ray spectroscopy from which optimum film thickness, may be determined by comparative analysis for capacitor fabrication purposes.

  1. Electrochemical micro sensor

    DOEpatents

    Setter, Joseph R.; Maclay, G. Jordan

    1989-09-12

    A micro-amperometric electrochemical sensor for detecting the presence of a pre-determined species in a fluid material is disclosed. The sensor includes a smooth substrate having a thin coating of solid electrolytic material deposited thereon. The working and counter electrodes are deposited on the surface of the solid electrolytic material and adhere thereto. Electrical leads connect the working and counter electrodes to a potential source and an apparatus for measuring the change in an electrical signal caused by the electrochemical oxidation or reduction of the species. Alternatively, the sensor may be fabricated in a sandwich structure and also may be cylindrical, spherical or other shapes.

  2. Electrochemical membrane incinerator

    DOEpatents

    Johnson, Dennis C.; Houk, Linda L.; Feng, Jianren

    2001-03-20

    Electrochemical incineration of p-benzoquinone was evaluated as a model for the mineralization of carbon in toxic aromatic compounds. A Ti or Pt anode was coated with a film of the oxides of Ti, Ru, Sn and Sb. This quaternary metal oxide film was stable; elemental analysis of the electrolyzed solution indicated the concentration of these metal ions to be 3 .mu.g/L or less. The anode showed good reactivity for the electrochemical incineration of benzoquinone. The use of a dissolved salt matrix as the so-called "supporting electrolyte" was eliminated in favor of a solid-state electrolyte sandwiched between the anode and cathode.

  3. Separators for electrochemical cells

    DOEpatents

    Carlson, Steven Allen; Anakor, Ifenna Kingsley

    2014-11-11

    Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Preferably, the inorganic oxide comprises an hydrated aluminum oxide of the formula Al.sub.2O.sub.3.xH.sub.2O, wherein x is less than 1.0, and wherein the hydrated aluminum oxide comprises organic substituents, preferably comprising a reaction product of a multifunctional monomer and/or organic carbonate with an aluminum oxide, such as pseudo-boehmite and an aluminum oxide. Also provided are electrochemical cells comprising such separators.

  4. The Reach Address Database (RAD)

    EPA Pesticide Factsheets

    The Reach Address Database (RAD) stores reach address information for each Water Program feature that has been linked to the underlying surface water features (streams, lakes, etc) in the National Hydrology Database (NHD) Plus dataset.

  5. Electrochemical nitridation of metal surfaces

    DOEpatents

    Wang, Heli; Turner, John A.

    2015-06-30

    Electrochemical nitridation of metals and the produced metals are disclosed. An exemplary method of electrochemical nitridation of metals comprises providing an electrochemical solution at low temperature. The method also comprises providing a three-electrode potentiostat system. The method also comprises stabilizing the three-electrode potentiostat system at open circuit potential. The method also comprises applying a cathodic potential to a metal.

  6. Automated measurement of printer effective addressability

    NASA Astrophysics Data System (ADS)

    Cooper, Brian E.; Eid, Ahmed H.; Rippetoe, Edward E.

    2014-01-01

    When evaluating printer resolution, addressability is a key consideration. Addressability defines the maximum number of spots or samples within a given distance, independent of the size of the spots when printed. Effective addressability is the addressability demonstrated by the final, printed output. It is the minimum displacement possible between the centers of printed objects. In this paper, we present a measurement procedure for effective addressability that offers an automated way to experimentally determine the addressability of the printed output. It requires printing, scanning, and measuring a test target. The effective addressability test target contains two types of elements, repeated to fill the page: fiducial lines and line segments. The fiducial lines serve as a relative reference for the incremental displacements of the individual line segments, providing a way to tolerate larger-scale physical distortions in the printer. An ordinary reflection scanner captures the printed test target. By rotating the page on the scanner, it is possible to measure effective addressability well beyond the scanner's sampling resolution. The measurement algorithm computes the distribution of incremental displacements, forming either a unimodal or bimodal histogram. In the latter case, the mean of the second (non-zero) peak indicates the effective addressability. In the former case, the printer successfully rendered the target's resolution, requiring another iteration of the procedure after increasing the resolution of the test target. The algorithm automatically estimates whether the histogram is unimodal or bimodal and computes parameters describing the quality of the measured histogram. Several experiments have refined the test target and measurement procedure, including two round-robin evaluations by the ISO WG4 committee. Results include an analysis of approximately 150 printed samples. The effective addressability attribute and measurement procedure are included in

  7. Electro-chemical grinding

    NASA Technical Reports Server (NTRS)

    Feagans, P. L.

    1972-01-01

    Electro-chemical grinding technique has rotation speed control, constant feed rates, and contour control. Hypersonic engine parts of nickel alloys can be almost 100% machined, keeping tool pressure at virtual zero. Technique eliminates galling and permits constant surface finish and burr-free interrupted cutting.

  8. Electrochemical biosensors and nanobiosensors

    PubMed Central

    Hammond, Jules L.; Formisano, Nello; Carrara, Sandro; Tkac, Jan

    2016-01-01

    Electrochemical techniques have great promise for low-cost miniaturised easy-to-use portable devices for a wide range of applications–in particular, medical diagnosis and environmental monitoring. Different techniques can be used for biosensing, with amperometric devices taking the central role due to their widespread application in glucose monitoring. In fact, glucose biosensing takes an approximately 70% share of the biosensor market due to the need for diabetic patients to monitor their sugar levels several times a day, making it an appealing commercial market. In this review, we present the basic principles of electrochemical biosensor devices. A description of the different generations of glucose sensors is used to describe in some detail the operation of amperometric sensors and how the introduction of mediators can enhance the performance of the sensors. Electrochemical impedance spectroscopy is a technique being increasingly used in devices due to its ability to detect variations in resistance and capacitance upon binding events. Novel advances in electrochemical sensors, due to the use of nanomaterials such as carbon nanotubes and graphene, are presented as well as future directions that the field is taking. PMID:27365037

  9. Electrochemical systems configured to harvest heat energy

    DOEpatents

    Lee, Seok Woo; Yang, Yuan; Ghasemi, Hadi; Chen, Gang; Cui, Yi

    2017-01-31

    Electrochemical systems for harvesting heat energy, and associated electrochemical cells and methods, are generally described. The electrochemical cells can be configured, in certain cases, such that at least a portion of the regeneration of the first electrochemically active material is driven by a change in temperature of the electrochemical cell. The electrochemical cells can be configured to include a first electrochemically active material and a second electrochemically active material, and, in some cases, the absolute value of the difference between the first thermogalvanic coefficient of the first electrochemically active material and the second thermogalvanic coefficient of the second electrochemically active material is at least about 0.5 millivolts/Kelvin.

  10. Cyclic Voltammetry Experiment.

    ERIC Educational Resources Information Center

    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…

  11. Design and fabrication of a bending rotation fatigue test rig for in situ electrochemical analysis during fatigue testing of NiTi shape memory alloy wires

    SciTech Connect

    Neelakantan, Lakshman; Zglinski, Jenni Kristin; Eggeler, Gunther; Frotscher, Matthias

    2013-03-15

    The current investigation proposes a novel method for simultaneous assessment of the electrochemical and structural fatigue properties of nickel-titanium shape memory alloy (NiTi SMA) wires. The design and layout of an in situ electrochemical cell in a custom-made bending rotation fatigue (BRF) test rig is presented. This newly designed test rig allows performing a wide spectrum of experiments for studying the influence of fatigue on corrosion and vice versa. This can be achieved by performing ex situ and/or in situ measurements. The versatility of the combined electrochemical/mechanical test rig is demonstrated by studying the electrochemical behavior of NiTi SMA wires in 0.9% NaCl electrolyte under load. The ex situ measurements allow addressing various issues, for example, the influence of pre-fatigue on the localized corrosion resistance, or the influence of hydrogen on fatigue life. Ex situ experiments showed that a pre-fatigued wire is more susceptible to localized corrosion. The synergetic effect can be concluded from the polarization studies and specifically from an in situ study of the open circuit potential (OCP) transients, which sensitively react to the elementary repassivation events related to the local failure of the oxide layer. It can also be used as an indicator for identifying the onset of the fatigue failure.

  12. On the mechanism of electrochemical modulation of plasmonic resonances

    NASA Astrophysics Data System (ADS)

    Shao, L.-H.; Ruther, M.; Linden, S.; Wegener, M.; Weissmüller, J.

    2012-09-01

    Recent electrochemical experiments on gold-based photonic metamaterials have shown a sizable reversible tuning and modulation of plasmonic resonances. Here, we study the mechanism of the electrochemical modulation by measuring the change of the resonance transmittance and resonance frequency during underpotential deposition of Pb, Cu, and electrosorption of OH. The electric resistance change of the resonators is identified as decisive for the resonance transmittance change, while the space-charge layer at the metal surface shifts the resonance frequency.

  13. Gravitational effects on electrochemical batteries

    NASA Technical Reports Server (NTRS)

    Meredith, R. E.; Juvinall, G. L.; Uchiyama, A. A.

    1972-01-01

    The existing work on gravitational effects on electrochemical batteries is summarized, certain conclusions are drawn, and recommendations are made for future activities in this field. The effects of sustained high-G environments on cycle silver-zinc and nickel-cadmium cells have been evaluated over four complete cycles in the region of 10 to 75 G. Although no effects on high current discharge performances or on ampere-hour capacity were noted, severe zinc migration and sloughing of active material from the zinc electrode were observed. This latter effect constitutes real damage, and over a long period of time would result in loss of capacity. It is recommended that a zero-G battery experiment be implemented. Both an orbiting satellite and a sounding rocket approach are being considered.

  14. Analyzing the Messages of the State of the Union Address

    ERIC Educational Resources Information Center

    Kissling, Mark T.; Martell, Christopher C.

    2014-01-01

    In the era of smartphones and 24-hour news networks, the State of the Union address is a major event. All national media outlets--in print, on television, on the Internet--report on the address, some almost exclusively in the days leading up to and after the speech. In this article, considering their experiences teaching about the address, and…

  15. CONTENT-ADDRESSABLE MEMORY SYSTEMS,

    DTIC Science & Technology

    The utility of content -addressable memories (CAM’s) within a general purpose computing system is investigated. Word cells within CAM may be...addressed by the character of all or a part of cell contents . Multimembered sets of word cells may be addressed simultaneously. The distributed logical...package is developed which allows simulation of CAM commands within job programs run on the IBM 7090 and derives tallies of execution times corresponding to a particular realization of a CAM system . (Author)

  16. Study of Electrochemical Reduction of CO2 for Future Use in Secondary Microbial Electrochemical Technologies.

    PubMed

    Gimkiewicz, Carla; Hegner, Richard; Gutensohn, Mareike F; Koch, Christin; Harnisch, Falk

    2017-03-09

    The fluctuation and decentralization of renewable energy have triggered the search for respective energy storage and utilization. At the same time, a sustainable bioeconomy calls for the exploitation of CO2 as feedstock. Secondary microbial electrochemical technologies (METs) allow both challenges to be tackled because the electrochemical reduction of CO2 can be coupled with microbial synthesis. Because this combination creates special challenges, the electrochemical reduction of CO2 was investigated under conditions allowing microbial conversions, that is, for their future use in secondary METs. A reproducible electrodeposition procedure of In on a graphite backbone allowed a systematic study of formate production from CO2 with a high number of replicates. Coulomb efficiencies and formate production rates of up to 64.6±6.8 % and 0.013±0.002 mmolformate  h(-1)  cm(-2) , respectively, were achieved. Electrode redeposition, reusability, and long-term performance were investigated. Furthermore, the effect of components used in microbial media, that is, yeast extract, trace elements, and phosphate salts, on the electrode performance was addressed. The results demonstrate that the integration of electrochemical reduction of CO2 in secondary METs can become technologically relevant.

  17. System level electrochemical principles

    NASA Technical Reports Server (NTRS)

    Thaller, L. H.

    1985-01-01

    The traditional electrochemical storage concepts are difficult to translate into high power, high voltage multikilowatt storage systems. The increased use of electronics, and the use of electrochemical couples that minimize the difficulties associated with the corrective measures to reduce the cell to cell capacity dispersion were adopted by battery technology. Actively cooled bipolar concepts are described which represent some attractive alternative system concepts. They are projected to have higher energy densities lower volumes than current concepts. They should be easier to scale from one capacity to another and have a closer cell to cell capacity balance. These newer storage system concepts are easier to manage since they are designed to be a fully integrated battery. These ideas are referred to as system level electrochemistry. The hydrogen-oxygen regenerative fuel cells (RFC) is probably the best example of the integrated use of these principles.

  18. Electrochemical storage cell

    SciTech Connect

    Haberfellner, F.; Prappacher, G.

    1985-01-08

    Electrochemical storage cell of the sodium and sulfur type with at least one anode space for receiving the anolyte and a cathode space for receiving the catholyte, which are separated from each other by an alkali ion-conducting solid electrolyte and are bounded at least in some areas by a metallic housing. The cathode space is in communication via at least one connecting element with at least one supply container for the sodium polysulfide being formed in the chemical reaction.

  19. Electrochemical storage cell

    SciTech Connect

    Steinleitner, G.

    1984-05-01

    Electrochemical storage cell or battery with at least one anode space for receiving the anolyte and one cathode space for receiving the catholyte which spaces are separated from each other by an alkali ion-conducting solid electrolyte and are bounded at least in some places by a metallic housing. A safety space which is subdivided into at least two safety zones, adjoins at least in some places, the solid electrolyte.

  20. Molten Salt Electrochemical Systems.

    DTIC Science & Technology

    1983-05-31

    metal tetrafluoroborates were examined for similar behavior. Commercial samples of the lithium, sodium and potassium salts were used, while the...REPORT a PERID C £0 inal, 1 June 1980-31 March Molten Salt Electrochemical Systems 1983 6 PERFORMING OŘG. REPORT NUMBER 7. AUTHOR(a) I CONTRACT OR...dilfferent from Reporl) IS. KEY WORDS (Continue ora ow... side 55 n~cssay and Identify by block number ) Molten Salt , Phase Diagram, Electrolyte 30

  1. Remote electrochemical sensor

    DOEpatents

    Wang, Joseph; Olsen, Khris; Larson, David

    1997-01-01

    An electrochemical sensor for remote detection, particularly useful for metal contaminants and organic or other compounds. The sensor circumvents technical difficulties that previously prevented in-situ remote operations. The microelectrode, connected to a long communications cable, allows convenient measurements of the element or compound at timed and frequent intervals and instrument/sample distances of ten feet to more than 100 feet. The sensor is useful for both downhole groundwater monitoring and in-situ water (e.g., shipboard seawater) analysis.

  2. Electrochemical corrosion studies

    NASA Technical Reports Server (NTRS)

    Knockemus, W. W.

    1986-01-01

    The objective was to gain familiarity with the Model 350 Corrosion Measurement Console, to determine if metal protection by grease coatings can be measured by the polarization-resistance method, and to compare corrosion rates of 4130 steel coated with various greases. Results show that grease protection of steel may be determined electrochemically. Studies were also conducted to determine the effectiveness of certain corrosion inhibitors on aluminum and steel.

  3. Electrochemical flow capacitors

    DOEpatents

    Gogotsi, Yury; Presser, Volker; Kumbur, Emin Caglan

    2015-10-27

    The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).

  4. Electrochemical Quartz Crystal Nanobalance

    NASA Astrophysics Data System (ADS)

    Inzelt, György

    The method of piezoelectric microgravimetry (nanogravimetry) using an electrochemical quartz crystal microbalance (EQCM) or nanobalance (EQCN) can be considered as a novel and much more sensitive version of electrogravimetry. The EQCN technique has become a widely used technique in several areas of electrochemistry, electroanalytical chemistry, bioelectrochemistry, etc. [1-10]. Obviously, mass changes occurring during adsorption, sorption, electrosorption, electrodeposition, or spontaneous deposition can be followed, which is very helpful for the elucidation of reaction mechanism via identification of the species accumulated on the surface. These investigations include metal and alloy deposition, underpotential deposition, electroplating, synthesis of conducting polymers by electropolymerization, adsorption of biologically active materials, and analytical determination of small ions and biomolecules. Of course, the opposite processes, i.e., spontaneous dissolution, electrodissolution, corrosion, can also be studied. Electrochemical oscillations, in which the formation and oxidation of chemisorbed molecular fragments play a determining role, have been studied, too. The majority of the investigations have been devoted to ion and solvent transport associated with the redox transformations of electrochemically active polymers. Similar studies have been carried out regarding polynuclear surface layers such as metal hexacyanometalates as well as inorganic and organic microcrystals of different compositions.

  5. ELECTROCHEMICAL POWER FOR TRANSPORTATION

    SciTech Connect

    Cairns, Elton J.; Hietbrink, Earl H.

    1981-01-01

    This section includes some historical background of the rise and fall and subsequent rebirth of the electric vehicle; and a brief discussion of current transportation needs, and environmental and energy utilization issues that resulted in the renewed interest in applying electrochemical energy conversion technology to electric vehicle applications. Although energy utilization has evolved to be the most significant and important issue, the environmental issue will be discussed first in this section only because of its chronological occurrence. The next part of the chapter is a review of passenger and commercial electric vehicle technology with emphasis on vehicle design and demonstrated performance of vehicles with candidate power sources being developed. This is followed by a discussion of electrochemical power source requirements associated with future electric vehicles that can play a role in meeting modern transportation needs. The last part of the chapter includes first a discussion of how to identify candidate electrochemical systems that might be of interest in meeting electric vehicle power source requirements. This is then followed by a review of the current technological status of these systems and a discussion of the most significant problems that must be resolved before each candidate system can be a viable power source.

  6. Electrochemical carbon dioxide concentrator subsystem development

    NASA Technical Reports Server (NTRS)

    Koszenski, E. P.; Heppner, D. B.; Bunnell, C. T.

    1986-01-01

    The most promising concept for a regenerative CO2 removal system for long duration manned space flight is the Electrochemical CO2 Concentrator (EDC), which allows for the continuous, efficient removal of CO2 from the spacecraft cabin. This study addresses the advancement of the EDC system by generating subsystem and ancillary component reliability data through extensive endurance testing and developing related hardware components such as electrochemical module lightweight end plates, electrochemical module improved isolation valves, an improved air/liquid heat exchanger and a triple redundant relative humidity sensor. Efforts included fabrication and testing the EDC with a Sabatier CO2 Reduction Reactor and generation of data necessary for integration of the EDC into a space station air revitalization system. The results verified the high level of performance, reliability and durability of the EDC subsystem and ancillary hardware, verified the high efficiency of the Sabatier CO2 Reduction Reactor, and increased the overall EDC technology engineering data base. The study concluded that the EDC system is approaching the hardware maturity levels required for space station deployment.

  7. Electrochemically Modulated Separation for Plutonium Safeguards

    SciTech Connect

    Pratt, Sandra H.; Breshears, Andrew T.; Arrigo, Leah M.; Schwantes, Jon M.; Duckworth, Douglas C.

    2013-12-31

    Accurate and timely analysis of plutonium in spent nuclear fuel is critical in nuclear safeguards for detection of both protracted and rapid plutonium diversions. Gamma spectroscopy is a viable method for accurate and timely measurements of plutonium provided that the plutonium is well separated from the interfering fission and activation products present in spent nuclear fuel. Electrochemically modulated separation (EMS) is a method that has been used successfully to isolate picogram amounts of Pu from nitric acid matrices. With EMS, Pu adsorption may be turned "on" and "off" depending on the applied voltage, allowing for collection and stripping of Pu without the addition of chemical reagents. In this work, we have scaled up the EMS process to isolate microgram quantities of Pu from matrices encountered in spent nuclear fuel during reprocessing. Several challenges have been addressed including surface area limitations, radiolysis effects, electrochemical cell performance stability, and chemical interferences. After these challenges were resolved, 6 µg Pu was deposited in the electrochemical cell with approximately an 800-fold reduction of fission and activation product levels from a spent nuclear fuel sample. Modeling showed that these levels of Pu collection and interference reduction may not be sufficient for Pu detection by gamma spectroscopy. The main remaining challenges are to achieve a more complete Pu isolation and to deposit larger quantities of Pu for successful gamma analysis of Pu. If gamma analyses of Pu are successful, EMS will allow for accurate and timely on-site analysis for enhanced Pu safeguards.

  8. Parallel electrochemical treatment system and application for identifying acid-stable oxygen evolution electrocatalysts.

    PubMed

    Jones, Ryan J R; Shinde, Aniketa; Guevarra, Dan; Xiang, Chengxiang; Haber, Joel A; Jin, Jian; Gregoire, John M

    2015-02-09

    Many energy technologies require electrochemical stability or preactivation of functional materials. Due to the long experiment duration required for either electrochemical preactivation or evaluation of operational stability, parallel screening is required to enable high throughput experimentation. Imposing operational electrochemical conditions to a library of materials in parallel creates several opportunities for experimental artifacts. We discuss the electrochemical engineering principles and operational parameters that mitigate artifacts in the parallel electrochemical treatment system. We also demonstrate the effects of resistive losses within the planar working electrode through a combination of finite element modeling and illustrative experiments. Operation of the parallel-plate, membrane-separated electrochemical treatment system is demonstrated by exposing a composition library of mixed-metal oxides to oxygen evolution conditions in 1 M sulfuric acid for 2 h. This application is particularly important because the electrolysis and photoelectrolysis of water are promising future energy technologies inhibited by the lack of highly active, acid-stable catalysts containing only earth abundant elements.

  9. Electrochemically and bioelectrochemically induced ammonium recovery.

    PubMed

    Gildemyn, Sylvia; Luther, Amanda K; Andersen, Stephen J; Desloover, Joachim; Rabaey, Korneel

    2015-01-22

    Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made. This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems.

  10. Electrochemically and Bioelectrochemically Induced Ammonium Recovery

    PubMed Central

    Gildemyn, Sylvia; Luther, Amanda K.; Andersen, Stephen J.; Desloover, Joachim; Rabaey, Korneel

    2015-01-01

    Streams such as urine and manure can contain high levels of ammonium, which could be recovered for reuse in agriculture or chemistry. The extraction of ammonium from an ammonium-rich stream is demonstrated using an electrochemical and a bioelectrochemical system. Both systems are controlled by a potentiostat to either fix the current (for the electrochemical cell) or fix the potential of the working electrode (for the bioelectrochemical cell). In the bioelectrochemical cell, electroactive bacteria catalyze the anodic reaction, whereas in the electrochemical cell the potentiostat applies a higher voltage to produce a current. The current and consequent restoration of the charge balance across the cell allow the transport of cations, such as ammonium, across a cation exchange membrane from the anolyte to the catholyte. The high pH of the catholyte leads to formation of ammonia, which can be stripped from the medium and captured in an acid solution, thus enabling the recovery of a valuable nutrient. The flux of ammonium across the membrane is characterized at different anolyte ammonium concentrations and currents for both the abiotic and biotic reactor systems. Both systems are compared based on current and removal efficiencies for ammonium, as well as the energy input required to drive ammonium transfer across the cation exchange membrane. Finally, a comparative analysis considering key aspects such as reliability, electrode cost, and rate is made. This video article and protocol provide the necessary information to conduct electrochemical and bioelectrochemical ammonia recovery experiments. The reactor setup for the two cases is explained, as well as the reactor operation. We elaborate on data analysis for both reactor types and on the advantages and disadvantages of bioelectrochemical and electrochemical systems. PMID:25651406

  11. Ultrasensitive electrochemical biomolecular detection using nanostructured microelectrodes.

    PubMed

    Sage, Andrew T; Besant, Justin D; Lam, Brian; Sargent, Edward H; Kelley, Shana O

    2014-08-19

    clinically relevant concentrations and speeds. Using this platform, we have achieved attomolar detection levels of nucleic acids with overall assay times as short as 2 min. We also describe the adaptation of the sensing platform to allow for the measurement of uncharged analytes--a challenge for reporter systems that rely on the charge of an analyte. Furthermore, the capabilities of this system have been applied to address the many current and important clinical challenges involving the detection of pathogenic species, including both bacterial and viral infections and cancer biomarkers. This novel electrochemical platform, which achieves large molecular-to-electrical amplification by means of its unique redox-cycling readout strategy combined with rapid and efficient analyte capture that is aided by nanostructured microelectrodes, achieves excellent specificity and sensitivity in clinical samples in which analytes are present at low concentrations in complex matrices.

  12. Electric field effects in electrochemical CO2 reduction

    DOE PAGES

    Chen, Leanne D.; Urushihara, Makoto; Chan, Karen; ...

    2016-09-22

    Electrochemical reduction of CO2 has the potential to reduce greenhouse gas emissions while providing energy storage and producing chemical feedstocks. A mechanistic understanding of the process is crucial to the discovery of efficient catalysts, and an atomistic description of the electrochemical interface is a major challenge due to its complexity. Here, we examine the CO2 → CO electrocatalytic pathway on Ag(111) using density functional theory (DFT) calculations and an explicit model of the electrochemical interface. We show that the electric field from solvated cations in the double layer and their corresponding image charges on the metal surface significantly stabilizes keymore » intermediates—*CO2 and *COOH. At the field-stabilized sites, the formation of *CO is rate-determining. We present a microkinetic model that incorporates field effects and electrochemical barriers from ab initio calculations. As a result, the computed polarization curves show reasonable agreement with experiment without fitting any parameters.« less

  13. Electro-Chemically Enhanced Mechanical Polishing of Nickel Mandrels

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail; Ramsey, Brian; Engelhaupt, Darell

    2006-01-01

    Grinding and mechanical polishing techniques used for x-ray optics mandrel figuring lead to mid-frequency surface ripple. These small figure variations have to be addressed in order to improve the performance of the resulting x-ray mirrors. If the electrochemical etching is combined with mechanical polishing, the figuring and the surface finishing cm be done simultaneously and be used to correct the mid-frequency surface ripple. It is shown that the electrochemical mechanical polishing method allows selective removal of nickel alloy without mandrel surface microroughness degradation.

  14. An electrochemical nickel-catalyzed arylation of 3-amino-6-chloropyridazines.

    PubMed

    Sengmany, Stéphane; Vitu-Thiebaud, Arnaud; Le Gall, Erwan; Condon, Sylvie; Léonel, Eric; Thobie-Gautier, Christine; Pipelier, Muriel; Lebreton, Jacques; Dubreuil, Didier

    2013-01-18

    3-Amino-6-aryl- and 3-amino-6-heteroarylpyridazines have been obtained in generally good yield using a nickel-catalyzed electrochemical cross-coupling between 3-amino-6-chloropyridazines and aryl or heteroaryl halides at room temperature. Comparative experiments involving classical palladium-catalyzed reactions, such as Suzuki, Stille, or Negishi cross-couplings, reveal that the electrochemical method can constitute a reliable alternative tool for biaryl formation. A possible reaction mechanism is proposed on the basis of electrochemical analyses.

  15. Space Electrochemical Research and Technology

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The proceedings of NASA's third Space Electrochemical Research and Technology (SERT) conference are presented. The objective of the conference was to assess the present status and general thrust of research and development in those areas of electrochemical technology required to enable NASA missions in the next century. The conference provided a forum for the exchange of ideas and opinions of those actively involved in the field, in order to define new opportunities for the application of electrochemical processes in future NASA missions. Papers were presented in three technical areas: the electrochemical interface, the next generation in aerospace batteries and fuel cells, and electrochemistry for nonenergy storage applications.

  16. Electrochemical air revitalization system optimization investigation

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Schubert, F. H.; Hallick, T. M.

    1975-01-01

    A program to characterize a Breadboard of an Electrochemical Air Revitalization System (BEARS) was successfully completed. The BEARS is composed of three components: (1) a water vapor electrolysis module (WVEM) for O2 production and partial humidity control, (2) an electrochemical depolarized carbon dioxide concentrator module (EDCM) for CO2 control, and (3) a power-sharing controller, designed to utilize the power produced by the EDCM to partially offset the WVEM power requirements. It is concluded from the results of this work that the concept of electrochemical air revitalization with power-sharing is a viable solution to the problem of providing a localized topping force for O2 generation, CO2 removal and partial humidity control aboard manned spacecraft. Continued development of the EARS concept is recommended, applying the operational experience and limits identified during the BEARS program to testing of a one-man capacity system and toward the development of advanced system controls to optimize EARS operation for given interfaces and requirements. Successful completion of this development will produce timely technology necessary to plan future advanced environmental control and life support system programs and experiments.

  17. Development of a Microelectrode Array Sensing Platform for Combination Electrochemical and Spectrochemical Aqueous Ion Testing

    PubMed Central

    Gardner, Robert D.; Zhou, Anhong; Zufelt, Nephi A.

    2009-01-01

    A microelectrode array sensor platform was designed and fabricated to increase diversity, flexibility, and versatility of testing capabilities over that of traditionally reported sensor platforms. These new sensor platforms consist of 18 individual addressable microelectrodes, photolithography fabricated, that employ a glass base substrate and a resist polymer layer that acts as an insulating agent to protect the circuitry and wiring of the sensor from undesired solution interactions. Individually addressable microelectrodes increase diversity by allowing isolated electrochemical testing between electrodes, global array testing, or some combination of electrodes to perform electrochemical methods. Furthermore, because of the optical transparency of the glass base substrate and the resist mask layer, along with the small size of the electrode array, spectrochemical analysis is possible within the sample area that acts as electrochemical cell and cuvette, while the microelectrode array passively resides within the optical path length during spectrochemical testing. This unique arrangement offers improved testing possibilities for various applications, including simultaneous electrochemical and spectrochemical analysis in environmental testing, identification or quantification of possible species for bioavailability in the biotechnology field, and process control in industrial applications. Electrochemical characteristics and spectrochemcial use of the sensor platform are proven with potassium ferricyanide, an electrochemical standard analyte, and electrochemical measurements are compared against a commercially available working electrode of similar size. Additionally, the electrochemical method of differential pulse anodic stripping voltammetry is performed with the sensor platform to detect copper and lead heavy metal ions in aqueous solution, demonstrating the potential for use with environmental samples. PMID:20130752

  18. Anode materials for electrochemical waste destruction

    NASA Technical Reports Server (NTRS)

    Molton, Peter M.; Clarke, Clayton

    1990-01-01

    Electrochemical Oxidation (ECO) offers promise as a low-temperature, atmospheric pressure method for safe destruction of hazardous organic chemical wastes in water. Anode materials tend to suffer corrosion in the intensely oxidizing environment of the ECO cell. There is a need for cheaper, more resistant materials. In this experiment, a system is described for testing anode materials, with examples of several common anodes such as stainless steel, graphite, and platinized titanium. The ECO system is simple and safe to operate and the experiment can easily be expanded in scope to study the effects of different solutions, temperatures, and organic materials.

  19. Electrochemical removal of tannins from aqueous solutions

    SciTech Connect

    Buso, A.; Balbo, L.; Giomo, M.; Farnia, G.; Sandona, G.

    2000-02-01

    The application of electrochemical methods to remove tannins from wastewater was investigated. Gallotannic acid was used as the reference substance. Electrochemical experiments were performed using platinum electrodes. Macroscale potentiostatic or galvanostatic electrolyses were carried out with sodium sulfate or sodium chloride as supporting electrolytes, to analyze direct and indirect oxidation processes. Operating variables such as pH and chloride concentration were considered to determine their influence on the efficiency and energy consumption of the process. The simulation of a pilot plant was carried out with a mathematical model, the parameters of which were determined by fitting of experimental profiles. The results of a preliminary investigation on the oxidation-coagulation process using sacrificial electrodes are also reported.

  20. Address tracing for parallel machines

    NASA Technical Reports Server (NTRS)

    Stunkel, Craig B.; Janssens, Bob; Fuchs, W. Kent

    1991-01-01

    Recently implemented parallel system address-tracing methods based on several metrics are surveyed. The issues specific to collection of traces for both shared and distributed memory parallel computers are highlighted. Five general categories of address-trace collection methods are examined: hardware-captured, interrupt-based, simulation-based, altered microcode-based, and instrumented program-based traces. The problems unique to shared memory and distributed memory multiprocessors are examined separately.

  1. Addressing the underperformance of faculty and staff.

    PubMed

    Kenner, Carole; Pressler, Jana L

    2006-01-01

    Many new nursing leaders assuming work as deans, assistant deans, or interim deans have limited education, experience, or background to prepare them for the job. To assist new deans and those aspiring to be deans, the authors of this department, both deans, offer survival tips based on their personal experiences and insights. They address common issues, challenges, and opportunities that face academic executive teams, such as negotiating an executive contract, obtaining faculty lines, building effective work teams, managing difficult employees, and creating nimble organizational structure to respond to changing consumer, healthcare delivery, and community needs. The authors welcome counterpoint discussions with readers.

  2. Continuous organic electrochemical synthesis

    SciTech Connect

    Nobe, K.; Baizer, M.; Pintauro, P.; Park, K.; Gilbert, S.

    1984-07-01

    The electrochemical oxidation of glucose to gluconic acid and reduction of glucose to sorbitol has been successfully paired in an undivided packed bed electrode flow cell. The use of a Raney nickel powder catalytic cathode significantly improved the current efficiency for sorbitol production, as compared to a high hydrogen overpotential Zn(Hg) cathode. The optimum operating conditions for the paired synthesis are: activity W-2 Raney nickel powder cathode, graphite chip anode, a 1.6 M glucose and 0.4 M CaBr/sub 2/ initial solution composition, pH 6-7, 60/sup 0/C solution temperature, a current density of 250 to 500 mA and a solution volumetric flow rate of 100 ml min/sup -1/. Under these conditions the sorbitol current efficiencies are at least 80%, the glucose acid current efficiencies are 100% and the product yields are quantitative. A separation scheme for the paired synthesis has also been devised. It consists of the precipitation of the oxidation product (calcium gluconate) and the ethanol extraction of glucose and CaBr/sub 2/ from sorbitol. Based on a preliminary economic analysis of the cost of raw materials, energy and the electrochemical cell and separation equipment the cost of producing 1 lb calcium gluconate and 0.68 lb sorbitol in a paired synthesis was estimated to be $0.896. The cost of producing the same amount of sorbitol and calcium gluconate in separate electrochemical cells was calculated to be $1.20. Thus, the paired synthesis appears to be an economically viable process.

  3. Electrochemical incineration of wastes

    NASA Technical Reports Server (NTRS)

    Bockris, J. O. M.; Bhardwaj, R. C.; Tennakoon, C. L. K.

    1993-01-01

    There is an increasing concern regarding the disposal of human wastes in space vehicles. It is of utmost importance to convert such wastes into harmless products which can be recycled into an Environmental Life Support System (CELSS), which incorporates the growth of plants (e.g. wheat) and algae to supplement the diet of the astronauts. Chemical treatments have proven relatively unsatisfactory and tend to be increasingly so with increase of the mission duration. Similarly, the use of heat to destroy wastes and convert them to CO2 by the use of air or oxygen has the disadvantage and difficulty of dissipating heat in a space environment and to the inevitable presence of oxides of nitrogen and carbon monoxide in the effluent gases. In particular, electrochemical techniques offer several advantages including low temperatures which may be used and the absence of any NO and CO in the evolved gases. Successful research has been carried out in the electrochemical oxidation of wastes over the last several years. The major task for 1992 was to conduct parametric studies in preparation for the building of a breadboard system, i.e., an actual practical device to consume the daily waste output of one astronaut in 24 hours, electrochemical incineration of human wastes in space vehicles. One of the main objectives was to decide on the type of three dimensional or other electrode system that would suit this purpose. The various types of electrode systems which were considered for this purpose included: rotating disc electrode, micro-electrode (an array), vibrating electrode, jet electrode, and packed bed electrode.

  4. Wireless powering for electrochemical sensor

    NASA Astrophysics Data System (ADS)

    Peplowski, Andrzej; Janczak, Daniel; Jakubowska, Małgorzata

    2016-09-01

    System of wireless energy supply for a electrochemical sensor is presented. As a first step, various theoretical models of the sensor were considered and a new model, proper for the application studied, was proposed to enable further design stages. In the experiment conducted, it was verified, that the sensor, working in an amperometric mode and in the presence of constant or quasi-constant voltage supply, could be electrically approximated as element of the constant impedance value. Given this, power-consumption was calculated for the sensor using Ohm's law and the proof of concept device was fabricated to evaluate performance of the sensor under theoretically calculated conditions. The results obtained were comparable to the data previously recorded using conventional laboratory potentiostat. For verification of the resistive character of the sensor, chronoamperometric method was employed, with sensor's response complying with the theoretical prediction for quasi-constant powering signal and being influenced only by major voltage changes. Calculated power consumption of the sensor was Pmax. = 18.23μW. Concerning sensor's requirement for quasiconstant voltage, simple half-wave rectifier was designed that was connected to the antenna used for powering signal reception. In the second experiment, calibration of the sensor was performed, yielding sensitivity s = 2.03 μA/μmol/L and linear correlation coefficient ρ = 0.986 and thus confirming proper operation of the device in the conditions considered.

  5. Divided electrochemical cell assembly

    SciTech Connect

    King, Ch. J. H.

    1985-02-19

    A divided electrochemical cell assembly comprises stacked bipolar substantially square parallel planar electrodes and membranes. The corners and edges of the electrodes with bordering insulative spacers in juxtaposition with the chamber walls define four electrolyte circulation manifolds. Anolyte and catholyte channeling means permit the separate introduction of anolyte and catholyte into two of the manifolds and the withdrawal of anolyte and catholyte separately from at least two other manifolds. The electrodes and membranes are separated from one another by the insulative spacers which are also channeling means disposed to provide electrolyte channels across the interfaces of adjacent electrodes and membranes.

  6. Electrochemical storage cell

    SciTech Connect

    Fischer, W.; Hasenauer, D.

    1983-09-20

    An electrochemical storage cell is disclosed based on alkali metal and chalcogen comprising at least one anode space for the alkali metal anolyte and a cathode space for the chalcogen catholyte, with the anode space and the cathode space separated from each other by an alkali ion-conducting solid electrolyte wall and a metallic housing bounding the cell. The solid electrolyte wall has a plurality of spaced, outwardly extending hollow recesses, and at least one current collector disposed between each pair of adjacent recesses.

  7. Electrochemical storage cell

    SciTech Connect

    Steinleitner, G.

    1985-05-07

    Electrochemical storage cell of the alkali metal and chalcogen type with at least one anode space for the alkali metal anolyte, and a cathode space for the chalcogen catholyte, with the anode space and the cathode space separated from each other by an alkali ion-conducting solid electrolyte wall, the improvement comprising the addition in the anode space of sodium and of a capturing material with O/sub 2/-getter properties in an amount sufficient to absorb detrimental bound or free oxygen.

  8. Amplifying Electrochemical Indicators

    NASA Technical Reports Server (NTRS)

    Fan, Wenhong; Li, Jun; Han, Jie

    2004-01-01

    Dendrimeric reporter compounds have been invented for use in sensing and amplifying electrochemical signals from molecular recognition events that involve many chemical and biological entities. These reporter compounds can be formulated to target specific molecules or molecular recognition events. They can also be formulated to be, variously, hydrophilic or amphiphilic so that they are suitable for use at interfaces between (1) aqueous solutions and (2) electrodes connected to external signal-processing electronic circuits. The invention of these reporter compounds is expected to enable the development of highly miniaturized, low-power-consumption, relatively inexpensive, mass-producible sensor units for diverse applications.

  9. Electrochemical thinning of silicon

    DOEpatents

    Medernach, J.W.

    1994-01-11

    Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR). 14 figures.

  10. Electrochemical thinning of silicon

    DOEpatents

    Medernach, John W.

    1994-01-01

    Porous semiconducting material, e.g. silicon, is formed by electrochemical treatment of a specimen in hydrofluoric acid, using the specimen as anode. Before the treatment, the specimen can be masked. The porous material is then etched with a caustic solution or is oxidized, depending of the kind of structure desired, e.g. a thinned specimen, a specimen, a patterned thinned specimen, a specimen with insulated electrical conduits, and so on. Thinned silicon specimen can be subjected to tests, such as measurement of interstitial oxygen by Fourier transform infra-red spectroscopy (FTIR).

  11. Remote electrochemical sensor

    DOEpatents

    Wang, J.; Olsen, K.; Larson, D.

    1997-10-14

    An electrochemical sensor is described for remote detection, particularly useful for metal contaminants and organic or other compounds. The sensor circumvents technical difficulties that previously prevented in-situ remote operations. The microelectrode, connected to a long communications cable, allows convenient measurements of the element or compound at timed and frequent intervals and instrument/sample distances of ten feet to more than 100 feet. The sensor is useful for both downhole groundwater monitoring and in-situ water (e.g., shipboard seawater) analysis. 21 figs.

  12. Development of Simulators for Electrochemical Responses: Experimental and Pedagogical Applications

    SciTech Connect

    Feldberg, S W; Goldstein, C I; Rudolph, M

    1997-06-19

    The work carried out in this CRADA addressed the development of computational algorithms to simulate the response for commonly used electrochemical techniques. The goal was the incorporation of these algorithms into DigiSimR, a generalized simulator for cyclic voltammetry (CV). CV, a ubiquitously applied electroanalytical technique used by nonelectrochemists as well as electrochemists, is sometimes referred to as "electrochemical spectroscopy". The latest version, DigiSimR 2.1, is now being sold by the industrial partner, Bioanalytical Systems, Inc. The response of the electrochemical community to this latest program (as well as its predecessors, DigiSimR 2.0 and the DOS version; versions 2.0 and 2.1 are for Windows), has been uniformly positive and numerous publications are now appearing which feature its application.

  13. Electrochemical photovoltaic cells and electrodes

    DOEpatents

    Skotheim, Terje A.

    1984-01-01

    Improved electrochemical photovoltaic cells and electrodes for use therein, particularly electrodes employing amorphous silicon or polyacetylene coating are produced by a process which includes filling pinholes or porous openings in the coatings by electrochemical oxidation of selected monomers to deposit insulating polymer in the openings.

  14. Electrochemical Impedance Of Inorganic-Zinc-Coated Steel

    NASA Technical Reports Server (NTRS)

    Macdowell, Louis G.

    1992-01-01

    Report describes preliminary experiments to evaluate both direct-current and alternating-current electrochemical impedance measurements as candidate techniques for use in accelerated corrosion testing of mild-steel panels coated with inorganic zinc-rich primers and exposed to seaside air. Basic idea behind experiments to compare electrochemical impedance measurements with anticorrosion performances of coating materials to determine whether measurements can be used to predict performances. Part of continuing program to identify anticorrosion coating materials protecting steel panels adequately for as long as 5 years and beyond.

  15. Electrochemically Programmable Plasmonic Antennas.

    PubMed

    Dong, Shi; Zhang, Kai; Yu, Zhiping; Fan, Jonathan A

    2016-07-26

    Plasmonic antennas are building blocks in advanced nano-optical systems due to their ability to tailor optical response based on their geometry. We propose an electrochemical approach to program the optical properties of dipole antennas in a scalable, fast, and energy-efficient manner. These antennas comprise two arms, one serving as an anode and the other a cathode, separated by a solid electrolyte. As a voltage is applied between the antenna arms, a conductive filament either grows or dissolves within the electrolyte, modifying the antenna load. We probe the dynamics of stochastic filament formation and their effects on plasmonic mode programming using a combination of three-dimensional optical and electronic simulations. In particular, we identify device operation regimes in which the charge-transfer plasmon mode can be programmed to be "on" or "off." We also identify, unexpectedly, a strong correlation between DC filament resistance and charge-transfer plasmon mode frequency that is insensitive to the detailed filament morphology. We envision that the scalability of our electrochemical platform can generalize to large-area reconfigurable metamaterials and metasurfaces for on-chip and free-space applications.

  16. Electrochemically regenerable carbon dioxide absorber

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.; Heppner, D. B.

    1979-01-01

    Preliminary designs were generated for two electrochemically regenerable carbon dioxide absorber concepts. Initially, an electrochemically regenerable absorption bed concept was designed. This concept incorporated the required electrochemical regeneration components in the absorber design, permitting the absorbent to be regenerated within the absorption bed. This hardware was identified as the electrochemical absorber hardware. The second hardware concept separated the functional components of the regeneration and absorption process. This design approach minimized the extravehicular activity component volume by eliminating regeneration hardware components within the absorber. The electrochemical absorber hardware was extensively characterized for major operating parameters such as inlet carbon dioxide partial pressure, process air flow rate, operational pressure, inlet relative humidity, regeneration current density and absorption/regeneration cycle endurance testing.

  17. Electrochemical biosensors for hormone analyses.

    PubMed

    Bahadır, Elif Burcu; Sezgintürk, Mustafa Kemal

    2015-06-15

    Electrochemical biosensors have a unique place in determination of hormones due to simplicity, sensitivity, portability and ease of operation. Unlike chromatographic techniques, electrochemical techniques used do not require pre-treatment. Electrochemical biosensors are based on amperometric, potentiometric, impedimetric, and conductometric principle. Amperometric technique is a commonly used one. Although electrochemical biosensors offer a great selectivity and sensitivity for early clinical analysis, the poor reproducible results, difficult regeneration steps remain primary challenges to the commercialization of these biosensors. This review summarizes electrochemical (amperometric, potentiometric, impedimetric and conductometric) biosensors for hormone detection for the first time in the literature. After a brief description of the hormones, the immobilization steps and analytical performance of these biosensors are summarized. Linear ranges, LODs, reproducibilities, regenerations of developed biosensors are compared. Future outlooks in this area are also discussed.

  18. High-Speed Electrochemical Imaging.

    PubMed

    Momotenko, Dmitry; Byers, Joshua C; McKelvey, Kim; Kang, Minkyung; Unwin, Patrick R

    2015-09-22

    The design, development, and application of high-speed scanning electrochemical probe microscopy is reported. The approach allows the acquisition of a series of high-resolution images (typically 1000 pixels μm(-2)) at rates approaching 4 seconds per frame, while collecting up to 8000 image pixels per second, about 1000 times faster than typical imaging speeds used up to now. The focus is on scanning electrochemical cell microscopy (SECCM), but the principles and practicalities are applicable to many electrochemical imaging methods. The versatility of the high-speed scan concept is demonstrated at a variety of substrates, including imaging the electroactivity of a patterned self-assembled monolayer on gold, visualization of chemical reactions occurring at single wall carbon nanotubes, and probing nanoscale electrocatalysts for water splitting. These studies provide movies of spatial variations of electrochemical fluxes as a function of potential and a platform for the further development of high speed scanning with other electrochemical imaging techniques.

  19. In Vitro Electrochemical Corrosion and Cell Viability Studies on Nickel-Free Stainless Steel Orthopedic Implants

    PubMed Central

    Salahinejad, Erfan; Hadianfard, Mohammad Jafar; Macdonald, Digby Donald; Sharifi-Asl, Samin; Mozafari, Masoud; Walker, Kenneth J.; Rad, Armin Tahmasbi; Madihally, Sundararajan V.; Tayebi, Lobat

    2013-01-01

    The corrosion and cell viability behaviors of nanostructured, nickel-free stainless steel implants were studied and compared with AISI 316L. The electrochemical studies were conducted by potentiodynamic polarization and electrochemical impedance spectroscopic measurements in a simulated body fluid. Cytocompatibility was also evaluated by the adhesion behavior of adult human stem cells on the surface of the samples. According to the results, the electrochemical behavior is affected by a compromise among the specimen's structural characteristics, comprising composition, density, and grain size. The cell viability is interpreted by considering the results of the electrochemical impedance spectroscopic experiments. PMID:23630603

  20. Application of electrochemical investigation methods in high sulfur coal flotation

    SciTech Connect

    Zhu Hong; Ou Zeshen; Shi Xiuping; Shen Yanchun

    1997-12-31

    More and more attention has been paid to sulfur dioxide pollution caused by coal burning. It is important that sulfur in coal should be reduced before combustion. Flotation is an important method for the removal of pyrite from high sulfur coal. Many chemicals have been tested as a pyrite depressant. In recent years many tests have been done in the laboratory on the flotation behavior of pyrite, and the results have confirmed that the hydrophobicity of the pyrite surface is dependent on the redox potential of the pulp. The mechanism and the reaction products on the pyrite surface are discussed under various conditions. And pyrite depression in coal flotation by electrochemical control are further studied on the basis of what has been achieved. There are two methods in electrochemical control: chemical reagent and control potential by electrochemical instrument (``control potential`` for short). This paper studies pyrite depression in coal flotation by electrochemical control. The influence of sulfur removal in coal flotation has been probed by chemical reagent and control potential. Experiment shows that at low pulp potential the pyrite flotation is generally suppressed. This is new, efficient and simple method of pyrite depression without environmental pollution. The following main conclusions can be drawn from this study: (1) The control of pulp potential can regulate and lead to electrochemical reaction of the hydrophobicity or hydrophilicity on the pyrite surface; and (2) The characteristics of electrochemical methods are normal atmospheric temperature, simple technological process and strong selection.

  1. Technology Base Research Project for electrochemical energy storage

    SciTech Connect

    Kinoshita, Kim

    1991-06-01

    The US DOE's Office of Propulsion Systems provides support for an electrochemical energy storage program, which includes R D on advanced rechargeable batteries and fuel cells. A major goal of this program is to develop electrochemical power sources suitable for application in electric vehicles (EVs). The program centers on advanced systems that offer the potential for high performance and low life-cycle costs, both of which are necessary to permit significant penetration into commercial markets. The general R D areas addressed by the project include identification of new electrochemical couples for advanced batteries, determination of technical feasibility of the new couples, improvements in battery components and materials, establishment of engineering principles applicable to electrochemical energy storage and conversion, and the development of air-system (fuel cell, metal/air) technology for transportation applications. Major emphasis is given to applied research which will lead to superior performance and lower life-cycle costs. The TBR Project is divided into three major project elements: Exploratory Research, Applied Science Research, and Air Systems Research. Highlights of each project element are summarized according to the appropriate battery system or electrochemical research area. 16 figs., 4 tabs.

  2. Electrochemically active biofilms: facts and fiction. A review.

    PubMed

    Babauta, Jerome; Renslow, Ryan; Lewandowski, Zbigniew; Beyenal, Haluk

    2012-01-01

    This review examines the electrochemical techniques used to study extracellular electron transfer in the electrochemically active biofilms that are used in microbial fuel cells and other bioelectrochemical systems. Electrochemically active biofilms are defined as biofilms that exchange electrons with conductive surfaces: electrodes. Following the electrochemical conventions, and recognizing that electrodes can be considered reactants in these bioelectrochemical processes, biofilms that deliver electrons to the biofilm electrode are called anodic, ie electrode-reducing, biofilms, while biofilms that accept electrons from the biofilm electrode are called cathodic, ie electrode-oxidizing, biofilms. How to grow these electrochemically active biofilms in bioelectrochemical systems is discussed and also the critical choices made in the experimental setup that affect the experimental results. The reactor configurations used in bioelectrochemical systems research are also described and the authors demonstrate how to use selected voltammetric techniques to study extracellular electron transfer in bioelectrochemical systems. Finally, some critical concerns with the proposed electron transfer mechanisms in bioelectrochemical systems are addressed together with the prospects of bioelectrochemical systems as energy-converting and energy-harvesting devices.

  3. Electrochemically active biofilms: facts and fiction. A review

    PubMed Central

    Babauta, Jerome; Renslow, Ryan; Lewandowski, Zbigniew; Beyenal, Haluk

    2014-01-01

    This review examines the electrochemical techniques used to study extracellular electron transfer in the electrochemically active biofilms that are used in microbial fuel cells and other bioelectrochemical systems. Electrochemically active biofilms are defined as biofilms that exchange electrons with conductive surfaces: electrodes. Following the electrochemical conventions, and recognizing that electrodes can be considered reactants in these bioelectrochemical processes, biofilms that deliver electrons to the biofilm electrode are called anodic, ie electrode-reducing, biofilms, while biofilms that accept electrons from the biofilm electrode are called cathodic, ie electrode-oxidizing, biofilms. How to grow these electrochemically active biofilms in bioelec-trochemical systems is discussed and also the critical choices made in the experimental setup that affect the experimental results. The reactor configurations used in bioelectrochemical systems research are also described and the authors demonstrate how to use selected voltammetric techniques to study extracellular electron transfer in bioelectrochemical systems. Finally, some critical concerns with the proposed electron transfer mechanisms in bioelectrochemical systems are addressed together with the prospects of bioelectrochemical systems as energy-converting and energy-harvesting devices. PMID:22856464

  4. Electrochemical Sensing of Cortisol: A Recent Update

    PubMed Central

    Singh, Aparajita; Kaushik, Ajeet; Kumar, Rajesh; Nair, Madhavan; Bhansali, Shekhar

    2014-01-01

    Psychological stress caused by everyday life style contributes to health disparities experience by individuals. It affects many biomarkers, but cortisol “a steroid hormone” is known as a potential biomarker for psychological stress detection. Abnormal levels of cortisol, is indicative of conditions such as Cushing’s syndrome Addison’s disease, adrenal insufficiencies and more recently post-traumatic stress disorder (PTSD). Chromatographic techniques, which are traditionally used to detect cortisol, are a complex system requiring multistep extraction/purification. This limits its application for point-of-care (POC) detection of cortisol. However, electrochemical immunosensing of cortisol is a recent advancement towards POC application. This review highlights simple, low-cost, and label-free electrochemical immunosensing platforms which have been developed recently for sensitive and selective detection of cortisol in biofluids. Electrochemical detection is utilized for the detection of cortisol using Anti-Cortisol antibodies (Anti-Cab) covalently immobilized on nanostructures such as self-assembled monolayer (SAM), polymer composite, etc. for POC integration of sensors. The observed information can be used as prototype to understand behavioral changes in humans in case to case such as farmers, fire fighters, etc. Keeping the future directions and challenges in mind the focus of the BioMEMS and Microsystems Research Group at Florida International University is on development of POC devices for immunosensing, integration of these devices with microfluidics, cross validation with existing technologies, and analysis of real sample. PMID:24723204

  5. High temperature electrochemical corrosion rate probes

    SciTech Connect

    Bullard, Sophie J.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, M.

    2005-09-01

    Corrosion occurs in the high temperature sections of energy production plants due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Electrochemical corrosion rate (ECR) probes have been shown to operate in high temperature gaseous environments that are similar to those found in fossil fuel combustors. ECR probes are rarely used in energy production plants at the present time, but if they were more fully understood, corrosion could become a process variable at the control of plant operators. Research is being conducted to understand the nature of these probes. Factors being considered are values selected for the Stern-Geary constant, the effect of internal corrosion, and the presence of conductive corrosion scales and ash deposits. The nature of ECR probes will be explored in a number of different atmospheres and with different electrolytes (ash and corrosion product). Corrosion rates measured using an electrochemical multi-technique capabilities instrument will be compared to those measured using the linear polarization resistance (LPR) technique. In future experiments, electrochemical corrosion rates will be compared to penetration corrosion rates determined using optical profilometry measurements.

  6. Electrochemical sensor for monitoring electrochemical potentials of fuel cell components

    DOEpatents

    Kunz, Harold R.; Breault, Richard D.

    1993-01-01

    An electrochemical sensor comprised of wires, a sheath, and a conduit can be utilized to monitor fuel cell component electric potentials during fuel cell shut down or steady state. The electrochemical sensor contacts an electrolyte reservoir plate such that the conduit wicks electrolyte through capillary action to the wires to provide water necessary for the electrolysis reaction which occurs thereon. A voltage is applied across the wires of the electrochemical sensor until hydrogen evolution occurs at the surface of one of the wires, thereby forming a hydrogen reference electrode. The voltage of the fuel cell component is then determined with relation to the hydrogen reference electrode.

  7. In Situ Investigation of Electrochemically Mediated Surface-Initiated Atom Transfer Radical Polymerization by Electrochemical Surface Plasmon Resonance.

    PubMed

    Chen, Daqun; Hu, Weihua

    2017-03-28

    Electrochemically mediated atom transfer radical polymerization (eATRP) initiates/controls the controlled/living ATRP chain propagation process by electrochemically generating (regenerating) the activator (lower-oxidation-state metal complex) from deactivator (higher-oxidation-state metal complex). Despite successful demonstrations in both of homogeneous polymerization and heterogeneous system (namely, surface-initiated ATRP, SI-ATRP), the eATRP process itself has never been in situ investigated, and important information regarding this process remains unrevealed. In this work, we report the first investigation of the electrochemically mediated SI-ATRP (eSI-ATRP) by rationally combining electrochemical technique with real-time surface plasmon resonance (SPR). In the experiment, the potential of a SPR gold chip modified by self-assembled monolayer of ATRP initiator was controlled to electrochemically reduce the deactivator to activator to initiate the SI-ATRP, and the whole process was simultaneously monitored by SPR with a high time resolution of 0.1 s. It is found that it is feasible to electrochemically trigger/control the SI-ATRP and the polymerization rate is correlated to the potential applied to the gold chip. This work reveals important kinetic information on eSI-ATRP, and offers a powerful platform for in situ investigation of such complicated processes.

  8. Agenda to address climate change

    SciTech Connect

    1998-10-01

    This document looks at addressing climate change in the 21st century. Topics covered are: Responding to climate change; exploring new avenues in energy efficiency; energy efficiency and alternative energy; residential sector; commercial sector; industrial sector; transportation sector; communities; renewable energy; understanding forests to mitigate and adapt to climate change; the Forest Carbon budget; mitigation and adaptation.

  9. Addressing Phonological Questions with Ultrasound

    ERIC Educational Resources Information Center

    Davidson, Lisa

    2005-01-01

    Ultrasound can be used to address unresolved questions in phonological theory. To date, some studies have shown that results from ultrasound imaging can shed light on how differences in phonological elements are implemented. Phenomena that have been investigated include transitional schwa, vowel coalescence, and transparent vowels. A study of…

  10. Keynote Address: Rev. Mark Massa

    ERIC Educational Resources Information Center

    Massa, Mark S.

    2011-01-01

    Rev. Mark S. Massa, S.J., is the dean and professor of Church history at the School of Theology and Ministry at Boston College. He was invited to give a keynote to begin the third Catholic Higher Education Collaborative Conference (CHEC), cosponsored by Boston College and Fordham University. Fr. Massa's address posed critical questions about…

  11. State of the Lab Address

    ScienceCinema

    King, Alex

    2016-07-12

    In his third-annual State of the Lab address, Ames Laboratory Director Alex King called the past year one of "quiet but strong progress" and called for Ames Laboratory to continue to build on its strengths while responding to changing expectations for energy research.

  12. Research strategies for addressing uncertainties

    USGS Publications Warehouse

    Busch, David E.; Brekke, Levi D.; Averyt, Kristen; Jardine, Angela; Welling, Leigh; Garfin, Gregg; Jardine, Angela; Merideth, Robert; Black, Mary; LeRoy, Sarah

    2013-01-01

    Research Strategies for Addressing Uncertainties builds on descriptions of research needs presented elsewhere in the book; describes current research efforts and the challenges and opportunities to reduce the uncertainties of climate change; explores ways to improve the understanding of changes in climate and hydrology; and emphasizes the use of research to inform decision making.

  13. Electrochemical storage cell

    SciTech Connect

    Hartmann, B.; Kleinschmager, H.

    1980-12-16

    An electrochemical storage cell or battery with an anode space for an alkali metal as the anolyte and with a cathode space for a sulfur-containing catholyte substance, which are separated from each other by an alkali-ion-conducting solid electrolyte and are confined by a cell wall of metal, particularly of a light metal or steel is described. Long-life corrosion protection of the metal cell wall is provided by a protective layer by applying to at least that part of the metal cell wall in contact with the catholyte substance, a foil of corrosion-resistant material 0.01 to 0.2 mm thick by means of a conductive adhesive which retains its adhesive properties at operating temperatures.

  14. Electrochemical storage cell

    SciTech Connect

    Langpape, R.

    1984-06-05

    The invention relates to an electrochemical storage cell on the basis of alkali metal and chalcogen, particularly sodium and sulfur. The storage cell has an anode space for receiving the anolyte and a cathode space for receiving the catholyte. The two spaces are separated from each other by a cup-shaped solid electrolyte. The solid electrolyte is surrounded in the region of the anode space by a capillary structure over the entire length. The capillary structure has at least one widened portion which is formed by an outward-pointing bulge of the capillary structure. The widened portion extends over the entire length of the capillary structure. Each widened portion is traversed in its interior by a canal. The cylinder surface of this canal is formed by a metal screen. The entrance opening of this canal is directly adjacent to the exit opening of a supply container for the sodium.

  15. Fast electrochemical actuator

    NASA Astrophysics Data System (ADS)

    Uvarov, I. V.; Postnikov, A. V.; Svetovoy, V. B.

    2016-03-01

    Lack of fast and strong microactuators is a well-recognized problem in MEMS community. Electrochemical actuators can develop high pressure but they are notoriously slow. Water electrolysis produced by short voltage pulses of alternating polarity can overcome the problem of slow gas termination. Here we demonstrate an actuation regime, for which the gas pressure is relaxed just for 10 μs or so. The actuator consists of a microchamber filled with the electrolyte and covered with a flexible membrane. The membrane bends outward when the pressure in the chamber increases. Fast termination of gas and high pressure developed in the chamber are related to a high density of nanobubbles in the chamber. The physical processes happening in the chamber are discussed so as problems that have to be resolved for practical applications of this actuation regime. The actuator can be used as a driving engine for microfluidics.

  16. Electrochemical cell design

    DOEpatents

    Arntzen, John D.

    1978-01-01

    An electrochemical cell includes two outer electrodes and a central electrode of opposite polarity, all nested within a housing having two symmetrical halves which together form an offset configuration. The outer electrodes are nested within raised portions within the side walls of each housing half while the central electrode sealingly engages the perimetric margins of the side-wall internal surfaces. Suitable interelectrode separators and electrical insulating material electrically isolate the central electrode from the housing and the outer electrodes. The outer electrodes are electrically connected to the internal surfaces of the cell housing to provide current collection. The nested structure minimizes void volume that would otherwise be filled with gas or heavy electrolyte and also provides perimetric edge surfaces for sealing and supporting at the outer margins of frangible interelectrode separator layers.

  17. Electrochemical catalyst recovery method

    DOEpatents

    Silva, Laura J.; Bray, Lane A.

    1995-01-01

    A method of recovering catalyst material from latent catalyst material solids includes: a) combining latent catalyst material solids with a liquid acid anolyte solution and a redox material which is soluble in the acid anolyte solution to form a mixture; b) electrochemically oxidizing the redox material within the mixture into a dissolved oxidant, the oxidant having a potential for oxidation which is effectively higher than that of the latent catalyst material; c) reacting the oxidant with the latent catalyst material to oxidize the latent catalyst material into at least one oxidized catalyst species which is soluble within the mixture and to reduce the oxidant back into dissolved redox material; and d) recovering catalyst material from the oxidized catalyst species of the mixture. The invention is expected to be particularly useful in recovering spent catalyst material from petroleum hydroprocessing reaction waste products having adhered sulfides, carbon, hydrocarbons, and undesired metals, and as well as in other industrial applications.

  18. Electrochemical catalyst recovery method

    DOEpatents

    Silva, L.J.; Bray, L.A.

    1995-05-30

    A method of recovering catalyst material from latent catalyst material solids includes: (a) combining latent catalyst material solids with a liquid acid anolyte solution and a redox material which is soluble in the acid anolyte solution to form a mixture; (b) electrochemically oxidizing the redox material within the mixture into a dissolved oxidant, the oxidant having a potential for oxidation which is effectively higher than that of the latent catalyst material; (c) reacting the oxidant with the latent catalyst material to oxidize the latent catalyst material into at least one oxidized catalyst species which is soluble within the mixture and to reduce the oxidant back into dissolved redox material; and (d) recovering catalyst material from the oxidized catalyst species of the mixture. The invention is expected to be particularly useful in recovering spent catalyst material from petroleum hydroprocessing reaction waste products having adhered sulfides, carbon, hydrocarbons, and undesired metals, and as well as in other industrial applications. 3 figs.

  19. Electrochemical Hydrogen Compressor

    SciTech Connect

    Lipp, Ludwig

    2016-01-21

    Conventional compressors have not been able to meet DOE targets for hydrogen refueling stations. They suffer from high capital cost, poor reliability and pose a risk of fuel contamination from lubricant oils. This project has significantly advanced the development of solid state hydrogen compressor technology for multiple applications. The project has achieved all of its major objectives. It has demonstrated capability of Electrochemical Hydrogen Compression (EHC) technology to potentially meet the DOE targets for small compressors for refueling sites. It has quantified EHC cell performance and durability, including single stage hydrogen compression from near-atmospheric pressure to 12,800 psi and operation of EHC for more than 22,000 hours. Capital cost of EHC was reduced by 60%, enabling a path to meeting the DOE cost targets for hydrogen compression, storage and delivery ($2.00-2.15/gge by 2020).

  20. Electrochemically controlled iron isotope fractionation

    NASA Astrophysics Data System (ADS)

    Black, Jay R.; Young, Edward D.; Kavner, Abby

    2010-02-01

    Variations in the stable isotope abundances of transition metals have been observed in the geologic record and trying to understand and reconstruct the physical/environmental conditions that produced these signatures is an area of active research. It is clear that changes in oxidation state lead to large fractionations of the stable isotopes of many transition metals such as iron, suggesting that transition metal stable isotope signatures could be used as a paleo-redox proxy. However, the factors contributing to these observed stable isotope variations are poorly understood. Here we investigate how the kinetics of iron redox electrochemistry generates isotope fractionation. Through a combination of electrodeposition experiments and modeling of electrochemical processes including mass-transport, we show that electron transfer reactions are the cause of a large isotope separation, while mass transport-limited supply of reactant to the electrode attenuates the observed isotopic fractionation. Furthermore, the stable isotope composition of electroplated transition metals can be tuned in the laboratory by controlling parameters such as solution chemistry, reaction overpotential, and solution convection. These methods are potentially useful for generating isotopically-marked metal surfaces for tracking and forensic purposes. In addition, our studies will help interpret stable isotope data in terms of identifying underlying electron transfer processes in laboratory and natural samples.

  1. Process for electrochemically gasifying coal

    DOEpatents

    Botts, T.E.; Powell, J.R.

    1985-10-25

    A process is claimed for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution. 7 figs.

  2. Renewable-reagent electrochemical sensor

    DOEpatents

    Wang, Joseph; Olsen, Khris B.

    1999-01-01

    A new electrochemical probe(s) design allowing for continuous (renewable) reagent delivery. The probe comprises an integrated membrane-sampling/electrochemical sensor that prevents interferences from surface-active materials and greatly extends the linear range. The probe(s) is useful for remote or laboratory-based monitoring in connection with microdialysis sampling and electrochemical measurements of metals and organic compounds that are not readily detected in the absence of reacting with the compound. Also disclosed is a method of using the probe(s).

  3. Renewable-reagent electrochemical sensor

    DOEpatents

    Wang, J.; Olsen, K.B.

    1999-08-24

    A new electrochemical probe(s) design allowing for continuous (renewable) reagent delivery is described. The probe comprises an integrated membrane sampling/electrochemical sensor that prevents interferences from surface-active materials and greatly extends the linear range. The probe(s) is useful for remote or laboratory-based monitoring in connection with microdialysis sampling and electrochemical measurements of metals and organic compounds that are not readily detected in the absence of reacting with the compound. Also disclosed is a method of using the probe(s). 19 figs.

  4. Acousto-Optically Addressed Fourier Transform Matched Filters.

    DTIC Science & Technology

    1984-08-01

    ACOUSTO - OPTIC DEFLECTOR .............................. II. THE EXPERIMENT............................................. 2 FV XPERIMENTAl. RESULTS...tcohniqtie1 arc addressed using an acousto - optic beam deflector with good correlation signals resulting. Th is method may be used to address arrays of matched...essentially the standard Vander Lugt method for making matched filters, except for the addition of the acousto - optic deflector between the Fourier

  5. Atomic clusters with addressable complexity

    NASA Astrophysics Data System (ADS)

    Wales, David J.

    2017-02-01

    A general formulation for constructing addressable atomic clusters is introduced, based on one or more reference structures. By modifying the well depths in a given interatomic potential in favour of nearest-neighbour interactions that are defined in the reference(s), the potential energy landscape can be biased to make a particular permutational isomer the global minimum. The magnitude of the bias changes the resulting potential energy landscape systematically, providing a framework to produce clusters that should self-organise efficiently into the target structure. These features are illustrated for small systems, where all the relevant local minima and transition states can be identified, and for the low-energy regions of the landscape for larger clusters. For a 55-particle cluster, it is possible to design a target structure from a transition state of the original potential and to retain this structure in a doubly addressable landscape. Disconnectivity graphs based on local minima that have no direct connections to a lower minimum provide a helpful way to visualise the larger databases. These minima correspond to the termini of monotonic sequences, which always proceed downhill in terms of potential energy, and we identify them as a class of biminimum. Multiple copies of the target cluster are treated by adding a repulsive term between particles with the same address to maintain distinguishable targets upon aggregation. By tuning the magnitude of this term, it is possible to create assemblies of the target cluster corresponding to a variety of structures, including rings and chains.

  6. Electrochemical Oxygen Sensor Development for Liquid Sodium

    NASA Astrophysics Data System (ADS)

    Nollet, Billy K.

    Safe operation of a sodium-cooled fast reactor (SFR) requires in-depth understanding of the corrosion implications of liquid sodium coolant on reactor materials. Dissolved oxygen concentration is of particular importance in characterizing sodium attack, so an accurate means of measuring and controlling oxygen is crucial. There is significant room for improvement in current oxygen sensing technology, so extensive research has been conducted at the University of Wisconsin-Madison to address this issue. Experimental facilities and electrochemical oxygen sensors have been developed, tested, and analyzed. This research is discussed in detail in this report. The oxygen sensors tested in this research were developed using a yttria stabilized zirconia (YSZ) electrolyte whereas many of the past research in this field was conducted with yttria doped thoria (YDT or YST) electrolytes. Thorium, an alpha emitter, is expensive and increasingly difficult to acquire, so motivation to switch to a new material exists. YSZ is commonly used as the electrolyte for solid oxide fuel cells, and ample data is available for high temperature ionic conduction of this material. While some work has been done with YSZ in oxygen sensors (the automotive field, for example, uses YSZ O2 sensors), research on YSZ sensors in sodium is limited. A thorough study of YSZ-based electrochemical oxygen sensors must include detailed corrosion testing and analysis of YSZ in liquid sodium, careful oxygen sensor development and testing, and finally, a comprehensive analysis of the acquired sensor data. The research presented in this report describes the design and development of an electrochemical oxygen sensor for use in sodium using a YSZ electrolyte through the previously-mentioned steps. The designed sensors were subjected to a series of hypotheses which advance common understanding of oxygen sensor signal. These results were used in conjunction with past research to form reliable conclusions.

  7. Using Theater to Address Bullying

    ERIC Educational Resources Information Center

    Salas, Jo

    2005-01-01

    The acting out of personal experiences with bullying promotes compassion and allows all students, including bullies, victims and witnesses, to stand up for justice. Playback theaters interpret personal experiences in a creative, nonconfrontational and nonjudgmental way, demonstrating to students that the playback stage is a safe place where they…

  8. Design and fabrication of a bending rotation fatigue test rig for in situ electrochemical analysis during fatigue testing of NiTi shape memory alloy wires.

    PubMed

    Neelakantan, Lakshman; Zglinski, Jenni Kristin; Frotscher, Matthias; Eggeler, Gunther

    2013-03-01

    The current investigation proposes a novel method for simultaneous assessment of the electrochemical and structural fatigue properties of nickel-titanium shape memory alloy (NiTi SMA) wires. The design and layout of an in situ electrochemical cell in a custom-made bending rotation fatigue (BRF) test rig is presented. This newly designed test rig allows performing a wide spectrum of experiments for studying the influence of fatigue on corrosion and vice versa. This can be achieved by performing ex situ and∕or in situ measurements. The versatility of the combined electrochemical∕mechanical test rig is demonstrated by studying the electrochemical behavior of NiTi SMA wires in 0.9% NaCl electrolyte under load. The ex situ measurements allow addressing various issues, for example, the influence of pre-fatigue on the localized corrosion resistance, or the influence of hydrogen on fatigue life. Ex situ experiments showed that a pre-fatigued wire is more susceptible to localized corrosion. The synergetic effect can be concluded from the polarization studies and specifically from an in situ study of the open circuit potential (OCP) transients, which sensitively react to the elementary repassivation events related to the local failure of the oxide layer. It can also be used as an indicator for identifying the onset of the fatigue failure.

  9. A Task Force to Address Bullying.

    PubMed

    Keller, Ronald; Budin, Wendy C; Allie, Tammy

    2016-02-01

    Bullying in the workplace can create a dysfunctional environment that is associated with serious physical and psychological harm to the person being bullied. Nurses' experience with bullying has gained considerable attention in recent years, and warrants further discussion. Nurse leaders need to develop and implement effective bullying prevention initiatives that will foster the functioning of a professional and productive staff in a healthy work environment. The aim of this article is to review workplace bullying as experienced by nurses, and describe how nurses at a Magnet-designated academic medical center developed and implemented a bullying task force to address the problem.

  10. Electrochemical biofilm control: A review

    PubMed Central

    Sultana, Sujala T; Babauta, Jerome T; Beyenal, Haluk

    2015-01-01

    One of the methods of controlling biofilms that has widely been discussed in the literature is to apply a potential or electrical current to a metal surface on which the biofilm is growing. Although electrochemical biofilm control has been studied for decades, the literature is often conflicting, as is detailed in this review. The goals of this review are to (1) present the current status of knowledge regarding electrochemical biofilm control, (2) establish a basis for a fundamental definition of electrochemical biofilm control and requirements for studying it, (3) discuss current proposed mechanisms, and (4) introduce future directions in the field. It is expected that the review will provide researchers with guidelines on comparing data sets across the literature and generating comparable data sets. The authors believe that, with the correct design, electrochemical biofilm control has great potential for industrial use. PMID:26592420

  11. THE EFFECT OF VOLTAGE ON ELECTROCHEMICAL DEGRADATION OF TRICHLOROETHYLENE

    EPA Science Inventory

    This study investigates electrochemical degradation of Trichloroethylene (TCE) using granular graphite as electrodes in a flow-through reactor system. The experiments were conducted to obtain information on the effect of voltage and flow rates on the degradation rates of TCE. The...

  12. Electrochemical Hydrogen Evolution: Sabatier's Principle and the Volcano Plot

    ERIC Educational Resources Information Center

    Laursen, Anders B.; Varela, Ana Sofia; Dionigi, Fabio; Fanchiu, Hank; Miller, Chandler; Trinhammer, Ole L.; Rossmeisl, Jan; Dahl, Soren

    2012-01-01

    The electrochemical hydrogen evolution reaction (HER) is growing in significance as society begins to rely more on renewable energy sources such as wind and solar power. Thus, research on designing new, inexpensive, and abundant HER catalysts is important. Here, we describe how a simple experiment combined with results from density functional…

  13. Supported liquid membrane electrochemical separators

    DOEpatents

    Pemsler, J. Paul; Dempsey, Michael D.

    1986-01-01

    Supported liquid membrane separators improve the flexibility, efficiency and service life of electrochemical cells for a variety of applications. In the field of electrochemical storage, an alkaline secondary battery with improved service life is described in which a supported liquid membrane is interposed between the positive and negative electrodes. The supported liquid membranes of this invention can be used in energy production and storage systems, electrosynthesis systems, and in systems for the electrowinning and electrorefining of metals.

  14. Characterization of Electrochemically Generated Silver

    NASA Technical Reports Server (NTRS)

    Adam, Niklas; Martinez, James; Carrier, Chris

    2014-01-01

    Silver biocide offers a potential advantage over iodine, the current state of the art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. Low concentrations of silver (<500 ppb) have been shown to kill bacteria in water systems and keep it safe for potability. Silver does not require hardware to remove it from a water system, and therefore can provide a simpler means for disinfecting water. The Russian segment of the International Space Station has utilized an electrochemically generated silver solution, which is colloidal in nature. To be able to reliably provide a silver biocide to drinking water by electrochemical means would reduce mass required for removing another biocide such as iodine from the water. This would also aid in crew time required to replace iodine removal cartridges. Future long term missions would benefit from electrochemically produced silver as the biocide could be produced on demand and requires only a small concentration to be effective. Since it can also be consumed safely, there is less mass in removal hardware and little consumables required for production. The goal of this project initially is to understand the nature of the electrochemically produced silver, the particle sizes produced by the electrochemical cell and the effect that voltage adjustment has on the particle size. In literature, it has been documented that dissolved oxygen and pH have an effect on the ionization of the electrochemical silver so those parameters would be measured and possibly adjusted to understand their effect on the silver.

  15. Antitumor effects of electrochemical treatment

    PubMed Central

    González, Maraelys Morales; Zamora, Lisset Ortíz; Cabrales, Luis Enrique Bergues; Sierra González, Gustavo Victoriano; de Oliveira, Luciana Oliveira; Zanella, Rodrigo; Buzaid, Antonio Carlos; Parise, Orlando; Brito, Luciana Macedo; Teixeira, Cesar Augusto Antunes; Gomes, Marina das Neves; Moreno, Gleyce; Feo da Veiga, Venicio; Telló, Marcos; Holandino, Carla

    2013-01-01

    Electrochemical treatment is an alternative modality for tumor treatment based on the application of a low intensity direct electric current to the tumor tissue through two or more platinum electrodes placed within the tumor zone or in the surrounding areas. This treatment is noted for its great effectiveness, minimal invasiveness and local effect. Several studies have been conducted worldwide to evaluate the antitumoral effect of this therapy. In all these studies a variety of biochemical and physiological responses of tumors to the applied treatment have been obtained. By this reason, researchers have suggested various mechanisms to explain how direct electric current destroys tumor cells. Although, it is generally accepted this treatment induces electrolysis, electroosmosis and electroporation in tumoral tissues. However, action mechanism of this alternative modality on the tumor tissue is not well understood. Although the principle of Electrochemical treatment is simple, a standardized method is not yet available. The mechanism by which Electrochemical treatment affects tumor growth and survival may represent more complex process. The present work analyzes the latest and most important research done on the electrochemical treatment of tumors. We conclude with our point of view about the destruction mechanism features of this alternative therapy. Also, we suggest some mechanisms and strategies from the thermodynamic point of view for this therapy. In the area of Electrochemical treatment of cancer this tool has been exploited very little and much work remains to be done. Electrochemical treatment constitutes a good therapeutic option for patients that have failed the conventional oncology methods. PMID:23592904

  16. Identifying and Addressing Vaccine Hesitancy

    PubMed Central

    Kestenbaum, Lori A.; Feemster, Kristen A.

    2015-01-01

    In the 20th century, the introduction of multiple vaccines significantly reduced childhood morbidity, mortality, and disease outbreaks. Despite, and perhaps because of, their public health impact, an increasing number of parents and patients are choosing to delay or refuse vaccines. These individuals are described as vaccine hesitant. This phenomenon has developed due to the confluence of multiple social, cultural, political and personal factors. As immunization programs continue to expand, understanding and addressing vaccine hesitancy will be crucial to their successful implementation. This review explores the history of vaccine hesitancy, its causes, and suggested approaches for reducing hesitancy and strengthening vaccine acceptance. PMID:25875982

  17. Identifying and addressing vaccine hesitancy.

    PubMed

    Kestenbaum, Lori A; Feemster, Kristen A

    2015-04-01

    In the 20th century, the introduction of multiple vaccines significantly reduced childhood morbidity, mortality, and disease outbreaks. Despite, and perhaps because of, their public health impact, an increasing number of parents and patients are choosing to delay or refuse vaccines. These individuals are described as "vaccine hesitant." This phenomenon has developed due to the confluence of multiple social, cultural, political, and personal factors. As immunization programs continue to expand, understanding and addressing vaccine hesitancy will be crucial to their successful implementation. This review explores the history of vaccine hesitancy, its causes, and suggested approaches for reducing hesitancy and strengthening vaccine acceptance.

  18. Nanoscale content-addressable memory

    NASA Technical Reports Server (NTRS)

    Davis, Bryan (Inventor); Principe, Jose C. (Inventor); Fortes, Jose (Inventor)

    2009-01-01

    A combined content addressable memory device and memory interface is provided. The combined device and interface includes one or more one molecular wire crossbar memories having spaced-apart key nanowires, spaced-apart value nanowires adjacent to the key nanowires, and configurable switches between the key nanowires and the value nanowires. The combination further includes a key microwire-nanowire grid (key MNG) electrically connected to the spaced-apart key nanowires, and a value microwire-nanowire grid (value MNG) electrically connected to the spaced-apart value nanowires. A key or value MNGs selects multiple nanowires for a given key or value.

  19. Addressing inequities in healthy eating.

    PubMed

    Friel, Sharon; Hattersley, Libby; Ford, Laura; O'Rourke, Kerryn

    2015-09-01

    What, when, where and how much people eat is influenced by a complex mix of factors at societal, community and individual levels. These influences operate both directly through the food system and indirectly through political, economic, social and cultural pathways that cause social stratification and influence the quality of conditions in which people live their lives. These factors are the social determinants of inequities in healthy eating. This paper provides an overview of the current evidence base for addressing these determinants and for the promotion of equity in healthy eating.

  20. Addressing the workforce pipeline challenge

    SciTech Connect

    Leonard Bond; Kevin Kostelnik; Richard Holman

    2006-11-01

    A secure and affordable energy supply is essential for achieving U.S. national security, in continuing U.S. prosperity and in laying the foundations to enable future economic growth. To meet this goal the next generation energy workforce in the U.S., in particular those needed to support instrumentation, controls and advanced operations and maintenance, is a critical element. The workforce is aging and a new workforce pipeline, to support both current generation and new build has yet to be established. The paper reviews the challenges and some actions being taken to address this need.

  1. IDENTIFICATION OF CHLOROMETHANE FROMATION PATHS DURING ELECTROCHEMICAL DECHLORINATION OF TCE USING GRAPHITE ELECTRODES

    EPA Science Inventory

    The purpose of this research is to investigate the formation of chloromethane during TCE dechlorination in a mixed electrochemical reactor using graphite electrodes. Chloromethane was the major chlorinated organic compound detected in previous dechlorination experiments. In order...

  2. IDENTIFICATION OF CHLOROMETHANE FORMATION PATHS DURING ELECTROCHEMICAL DECHLORINATION OF TCE USING GRAPHITE ELECTRODES

    EPA Science Inventory

    The purpose of this research is to investigate the formation of chloromethane during TCE dechlorination in a mixed electrochemical reactor using graphite electrodes. Chloromethane was the major chlorinated organic compound detected in previous dechlorination experiments. In order...

  3. Electrochemical fluorination of trichloroethylene and N, N-dimethyltrifluoroacetamide

    NASA Technical Reports Server (NTRS)

    Hsu, L.-C.

    1979-01-01

    The paper presents the results of experiments concerning the fluorination of trichloroethylene and N, N-dimethyltrifluoroacetamide carried out on a laboratory scale in an advanced 'Simons' type electrochemical apparatus which could be operated automatically from ambient to 50 psi pressure. It is shown that a variety of fluorine-substituted products are formed, depending upon electrolysis conditions and concentrations of reactant relative to the NaF, KF, HF electrolyte. A new reaction mechanism of electrochemical fluorination of trichloroethylene is proposed. Finally, the solvency-to-fluorine content relationship of fluorinated N, N-dimethyltrifluoroacetamide is described.

  4. Electrochemical cell utilizing molten alkali metal electrode-reactant

    DOEpatents

    Virkar, Anil V.; Miller, Gerald R.

    1983-11-04

    An improved electrochemical cell comprising an additive-modified molten alkali metal electrode-reactant and/or electrolyte is disclosed. Various electrochemical cells employing a molten alkali metal, e.g., sodium, electrode in contact with a cationically conductive ceramic membrane experience a lower resistance and a lower temperature coefficient of resistance whenever small amounts of selenium are present at the interface of the electrolyte and the molten alkali metal. Further, cells having small amounts of selenium present at the electrolyte-molten metal interface exhibit less degradation of the electrolyte under long term cycling conditions.

  5. Nucleophilic aromatic substitution for heteroatoms: an oxidative electrochemical approach.

    PubMed

    Gallardo, Iluminada; Guirado, Gonzalo; Marquet, Jordi

    2002-04-19

    The nucleophilic aromatic substitution for heteroatom through electrochemical oxidation of the intermediate sigma-complexes (Meisenheimer complexes) in simple nitroaromatic compounds is reported for the first time (NASX process). The studies have been carried out with hydride, cyanide, fluoride, methoxy, and ethanethiolate anions and n-butylamine as a nucleophile, at the cyclic voltammetry (CV) and preparative electrolysis level. The cyclic voltammetry experiments allow for detection and characterization of the sigma-complexes and they have led us to a proposal for the mechanism of the oxidation step. Furthermore, the power of the CV technique in the analysis of the reaction mixture throughout the whole chemical and electrochemical process is described.

  6. Electrochemical planarization of copper surfaces with submicron features

    SciTech Connect

    Chalupa, R.; Andryushchenko, T.; Han, J.; Ghosh, T.; Shankar, S.; Fischer, P.

    2007-07-15

    Electrochemical planarization (ECP) of copper surfaces in a phosphoric acid-based electrolyte solution is discussed. A first-principles, quantum chemistry modeling work is presented that further validates the water-facilitated (and water rate limited) chemistry model for copper oxidation at the anode. This model has been previously deduced by other researchers [R. Vidal and A. West, J. Electrochem. Soc. 142, 2689 (1995); B. Du and I. I. Suni, J. Appl. Electrochem. 34, 1215 (2004); R. Vidal and A. West J. Electrochem. Soc. 142, 2682 (1995)] based on electrochemical experiments. Resulting water-limited model is validated against experimental data and applied to study the planarization behavior of a set of surface features. Aspect ratios and dimensions of these features were chosen to represent realistic (nonidealized, low aspect ratio structures) post-Damascene electroplate surface topography. Results are presented in a form of remaining feature amplitude versus mean copper thickness removed [A. C. West et al., J. Electrochem. Soc. 152, C652 (2005)]--allowing at-a-glance evaluation of the process against desired targets. The dominant effects of the mass transport boundary layer (BL) thickness on this planarization efficiency are discussed as are the challenges seen at typical flow conditions in ECP systems. Impact of changing the BL thickness and the requisite modulation of flow conditions analysis is included. Insights into practical challenges associated with BL buildup transient and associated surface roughening are summarized [D. Padhi et al., J. Electrochem. Soc. 150, 610 (2003)]. Challenges of applying ECP as a straightforward substitute to the robust chemical mechanical polish (CMP) process are significant. Practical modifications to upstream process flow to enable ECP would include optimized electroplating process or a CMP preprocessing step.

  7. The indirect electrochemical refining of lunar ores

    NASA Technical Reports Server (NTRS)

    Semkow, Krystyna W.; Sammells, Anthony F.

    1987-01-01

    Recent work performed on an electrolytic cell is reported which addresses the implicit limitations in various approaches to refining lunar ores. The cell uses an oxygen vacancy conducting stabilized zirconia solid electrolyte to effect separation between a molten salt catholyte compartment where alkali metals are deposited, and an oxygen-evolving anode of composition La(0.89)Sr(0.1)MnO3. The cell configuration is shown and discussed along with a polarization curve and a steady-state current-voltage curve. In a practical cell, cathodically deposited liquid lithium would be continuously removed from the electrolytic cell and used as a valuable reducing agent for ore refining under lunar conditions. Oxygen would be indirectly electrochemically extracted from lunar ores for breathing purposes.

  8. Electrochemical polishing of notches

    DOEpatents

    Kephart, Alan R.; Alberts, Alfred H.

    1989-01-01

    An apparatus and method are disclosed for the selective electrochemical polishing of a lateral tip of a deep longitudinal notch in a work piece used to test crack initiation properties of materials. A DC power source is connected to the work piece and to an electrode disposed laterally along the distal end of an insulated body which is inserted in the longitudinal notch. The electrode and distal end of the body are disposed along the tip of the notch, but are spaced from the notch so as to provide a lateral passage for an electrolyte. The electrolyte is circulated through the passage so that the electrolyte only contacts the work piece adjacent the passage. Conveniently, the electrolyte is circulated by use of an inlet tube and an outlet tube provided at opposite ends of the passage. These tubes are preferably detachably located adjacent the ends of the passage and suitable seals are provided. A holding device including arms to which the tubes are attached is conveniently used to rapidly and easily locate the test specimen with the passage aligned with the tubes. The electrode is preferably a wire which is located in grooves along the distal end of the insulated body and up one side of the body or a plastic sheath insulated thin metal strip.

  9. Electrochemical polishing of notches

    DOEpatents

    Kephart, A.R.; Alberts, A.H.

    1989-02-21

    An apparatus and method are disclosed for the selective electrochemical polishing of a lateral tip of a deep longitudinal notch in a work piece used to test crack initiation properties of materials. A DC power source is connected to the work piece and to an electrode disposed laterally along the distal end of an insulated body which is inserted in the longitudinal notch. The electrode and distal end of the body are disposed along the tip of the notch, but are spaced from the notch so as to provide a lateral passage for an electrolyte. The electrolyte is circulated through the passage so that the electrolyte only contacts the work piece adjacent the passage. Conveniently, the electrolyte is circulated by use of an inlet tube and an outlet tube provided at opposite ends of the passage. These tubes are preferably detachably located adjacent the ends of the passage and suitable seals are provided. A holding device including arms to which the tubes are attached is conveniently used to rapidly and easily locate the test specimen with the passage aligned with the tubes. The electrode is preferably a wire which is located in grooves along the distal end of the insulated body and up one side of the body or a plastic sheath insulated thin metal strip. 4 figs.

  10. Electrochemical incineration of wastes

    NASA Technical Reports Server (NTRS)

    Kaba, L.; Hitchens, G. D.; Bockris, J. OM.

    1989-01-01

    The disposal of domestic organic waste in its raw state is a matter of increasing public concern. Earlier, it was regarded as permissible to reject wastes into the apparently infinite sink of the sea but, during the last 20 years, it has become clear that this is environmentally unacceptable. On the other hand, sewage farms and drainage systems for cities and for new housing developments are cumbersome and expensive to build and operate. New technology whereby waste is converted to acceptable chemicals and pollution-free gases at site is desirable. The problems posed by wastes are particularly demanding in space vehicles where it is desirable to utilize treatments that will convert wastes into chemicals that can be recycled. In this situation, the combustion of waste is undesirable due to the inevitable presence of oxides of nitrogen and carbon monoxide in the effluent gases. Here, in particular, electrochemical techniques offer several advantages including the low temperatures which may be used and the absence of any NO and CO in the evolved gases. Work done in this area was restricted to technological papers, and the present report is an attempt to give a more fundamental basis to the early stages of a potentially valuable technology.

  11. Electrochemical Treatment of Textile Dye Wastewater by Mild Steel Anode.

    PubMed

    Bhavya, J G; Rekha, H B; Murthy, Usha N

    2014-04-01

    This paper presents the results of the treatment of textile dye wastewater generated from a textile processing industry by electrochemical method. Experiments were conducted at current densities of 12, 24 and 48 A/m2 using mild steel as anode and cathode. During the various stages of electrolysis, parameters such as COD, color and BOD5 were determined in order to know the feasibility of electrochemical treatment. It was observed that increasing the electrolysis time and increased current density bring down the concentration of pollutants. Also COD removal rate and energy consumption during the electrolysis were calculated and presented in this paper. The present study proves the effectiveness of electrochemical treatment using MS as anode for TDW oxidation.

  12. Assessing corrosion problems in photovoltaic cells via electrochemical stress testing

    NASA Technical Reports Server (NTRS)

    Shalaby, H.

    1985-01-01

    A series of accelerated electrochemical experiments to study the degradation properties of polyvinylbutyral-encapsulated silicon solar cells has been carried out. The cells' electrical performance with silk screen-silver and nickel-solder contacts was evaluated. The degradation mechanism was shown to be electrochemical corrosion of the cell contacts; metallization elements migrate into the encapsulating material, which acts as an ionic conducting medium. The corrosion products form a conductive path which results in a gradual loss of the insulation characteristics of the encapsulant. The precipitation of corrosion products in the encapsulant also contributes to its discoloration which in turn leads to a reduction in its transparency and the consequent optical loss. Delamination of the encapsulating layers could be attributed to electrochemical gas evolution reactions. The usefulness of the testing technique in qualitatively establishing a reliability difference between metallizations and antireflection coating types is demonstrated.

  13. Pulse electrochemical meso/micro/nano ultraprecision machining technology.

    PubMed

    Lee, Jeong Min; Kim, Young Bin; Park, Jeong Woo

    2013-11-01

    This study demonstrated meso/micro/nano-ultraprecision machining through electrochemical reactions using intermittent DC pulses. The experiment focused on two machining methods: (1) pulse electrochemical polishing (PECP) of stainless steel, and (2) pulse electrochemical nano-patterning (PECNP) on a silicon (Si) surface, using atomic force microscopy (AFM) for fabrication. The dissolution reaction at the stainless steel surface following PECP produced a very clean, smooth workpiece. The advantages of the PECP process included improvements in corrosion resistance, deburring of the sample surface, and removal of hydrogen from the stainless steel surface as verified by time-of-flight secondary-ion mass spectrometry (TOF-SIMS). In PECNP, the electrochemical reaction generated within water molecules produced nanoscale oxide textures on a Si surface. Scanning probe microscopy (SPM) was used to evaluate nanoscale-pattern processing on a Si wafer surface produced by AFM-PECNP For both processes using pulse electrochemical reactions, three-dimensional (3-D) measurements and AFM were used to investigate the changes on the machined surfaces. Preliminary results indicated the potential for advancing surface polishing techniques and localized micro/nano-texturing technology using PECP and PECNP processes.

  14. Electrochemical oxidation of imazapyr with BDD electrode in titanium substrate.

    PubMed

    Souza, F L; Teodoro, T Q; Vasconcelos, V M; Migliorini, F L; Lima Gomes, P C F; Ferreira, N G; Baldan, M R; Haiduke, R L A; Lanza, M R V

    2014-12-01

    In this work we have studied the treatment of imazapyr by electrochemical oxidation with boron-doped diamond anode. Electrochemical degradation experiments were performed in a one-compartment cell containing 0.45 L of commercial formulations of herbicide in the pH range 3.0-10.0 by applying a density current between 10 and 150 mA cm(-2) and in the temperature range 25-45 °C. The maximum current efficiencies were obtained at lower current densities since the electrochemical system is under mass transfer control. The mineralization rate increased in acid medium and at higher temperatures. The treatment was able to completely degrade imazapyr in the range 4.6-100.0 mg L(-1), although the current charge required rises along with the increasing initial concentration of the herbicide. Toxicity analysis with the bioluminescent bacterium Vibrio fischeri showed that at higher pollutant concentrations the toxicity was reduced after the electrochemical treatment. To clarify the reaction pathway for imazapyr mineralization by OH radicals, LC-MS/MS analyses we performed together with a theoretical study. Ions analysis showed the formation of high levels of ammonium in the cathode. The main final products of the electrochemical oxidation of imazapyr with diamond thin film electrodes are formic, acetic and butyric acids.

  15. Electrochemically driven, electrode-addressable formation of functionalized polydopamine films for neural interfaces.

    PubMed

    Kang, Kyungtae; Lee, Seokyoung; Kim, Raeyoung; Choi, Insung S; Nam, Yoonkey

    2012-12-21

    The electrode-specific formation of polydopamine films is achieved by applying positive voltage to the target electrodes at pH 6.0. The functionalization of the films is simultaneously carried out by co-depositing dopamine with molecules of interest onto the electrode.

  16. Content-addressable holographic databases

    NASA Astrophysics Data System (ADS)

    Grawert, Felix; Kobras, Sebastian; Burr, Geoffrey W.; Coufal, Hans J.; Hanssen, Holger; Riedel, Marc; Jefferson, C. Michael; Jurich, Mark C.

    2000-11-01

    Holographic data storage allows the simultaneous search of an entire database by performing multiple optical correlations between stored data pages and a search argument. We have recently developed fuzzy encoding techniques for this fast parallel search and demonstrated a holographic data storage system that searches digital data records with high fidelity. This content-addressable retrieval is based on the ability to take the two-dimensional inner product between the search page and each stored data page. We show that this ability is lost when the correlator is defocussed to avoid material oversaturation, but can be regained by the combination of a random phase mask and beam confinement through total internal reflection. Finally, we propose an architecture in which spatially multiplexed holograms are distributed along the path of the search beam, allowing parallel search of large databases.

  17. Addressing viral resistance through vaccines

    PubMed Central

    Laughlin, Catherine; Schleif, Amanda; Heilman, Carole A

    2015-01-01

    Antimicrobial resistance is a serious healthcare concern affecting millions of people around the world. Antiviral resistance has been viewed as a lesser threat than antibiotic resistance, but it is important to consider approaches to address this growing issue. While vaccination is a logical strategy, and has been shown to be successful many times over, next generation viral vaccines with a specific goal of curbing antiviral resistance will need to clear several hurdles including vaccine design, evaluation and implementation. This article suggests that a new model of vaccination may need to be considered: rather than focusing on public health, this model would primarily target sectors of the population who are at high risk for complications from certain infections. PMID:26604979

  18. Addressing Failures in Exascale Computing

    SciTech Connect

    Snir, Marc; Wisniewski, Robert; Abraham, Jacob; Adve, Sarita; Bagchi, Saurabh; Balaji, Pavan; Belak, J.; Bose, Pradip; Cappello, Franck; Carlson, Bill; Chien, Andrew; Coteus, Paul; DeBardeleben, Nathan; Diniz, Pedro; Engelmann, Christian; Erez, Mattan; Fazzari, Saverio; Geist, Al; Gupta, Rinku; Johnson, Fred; Krishnamoorthy, Sriram; Leyffer, Sven; Liberty, Dean; Mitra, Subhasish; Munson, Todd; Schreiber, Rob; Stearley, Jon; Van Hensbergen, Eric

    2014-01-01

    We present here a report produced by a workshop on Addressing failures in exascale computing' held in Park City, Utah, 4-11 August 2012. The charter of this workshop was to establish a common taxonomy about resilience across all the levels in a computing system, discuss existing knowledge on resilience across the various hardware and software layers of an exascale system, and build on those results, examining potential solutions from both a hardware and software perspective and focusing on a combined approach. The workshop brought together participants with expertise in applications, system software, and hardware; they came from industry, government, and academia, and their interests ranged from theory to implementation. The combination allowed broad and comprehensive discussions and led to this document, which summarizes and builds on those discussions.

  19. Addressing failures in exascale computing

    SciTech Connect

    Snir, Marc; Wisniewski, Robert W.; Abraham, Jacob A.; Adve, Sarita; Bagchi, Saurabh; Balaji, Pavan; Belak, Jim; Bose, Pradip; Cappello, Franck; Carlson, William; Chien, Andrew A.; Coteus, Paul; Debardeleben, Nathan A.; Diniz, Pedro; Engelmann, Christian; Erez, Mattan; Saverio, Fazzari; Geist, Al; Gupta, Rinku; Johnson, Fred; Krishnamoorthy, Sriram; Leyffer, Sven; Liberty, Dean; Mitra, Subhasish; Munson, Todd; Schreiber, Robert; Stearly, Jon; Van Hensbergen, Eric

    2014-05-01

    We present here a report produced by a workshop on “Addressing Failures in Exascale Computing” held in Park City, Utah, August 4–11, 2012. The charter of this workshop was to establish a common taxonomy about resilience across all the levels in a computing system; discuss existing knowledge on resilience across the various hardware and software layers of an exascale system; and build on those results, examining potential solutions from both a hardware and software perspective and focusing on a combined approach. The workshop brought together participants with expertise in applications, system software, and hardware; they came from industry, government, and academia; and their interests ranged from theory to implementation. The combination allowed broad and comprehensive discussions and led to this document, which summarizes and builds on those discussions.

  20. Light addressable photoelectrochemical cyanide sensor

    SciTech Connect

    Licht, S.; Myung, N.; Sun, Y.

    1996-03-15

    A sensor is demonstrated that is capable of spatial discrimination of cyanide with use of only a single stationary sensing element. Different spatial regions of the sensing element are light activated to reveal the solution cyanide concentration only at the point of illumination. In this light addressable photoelectrochemical (LAP) sensor the sensing element consists of an n-CdSe electrode immersed in solution, with the open-circuit potential determined under illumination. In alkaline ferro-ferri-cyanide solution, the open-circuit photopotential is highly responsive to cyanide, with a linear response of (120 mV) log [KCN]. LAP detection with a spatial resolution of {+-}1 mm for cyanide detection is demonstrated. The response is almost linear for 0.001-0.100 m cyanide with a resolution of 5 mV. 38 refs., 7 figs., 1 tab.

  1. Exploratory Technology Research Program for Electrochemical Energy Storage

    NASA Astrophysics Data System (ADS)

    Kinoshita, K.

    1993-10-01

    This report summarizes the progress made by the Exploratory Technology Research (ETR) Program for Electrochemical Energy Storage during calendar year 1992. The primary objective of the ETR Program, which is sponsored by the US Department of Energy (DOE) and managed by Lawrence Berkeley Laboratory (LBL), is to identify electrochemical technologies that can satisfy stringent performance, durability, and economic requirements for electric vehicles (EV's). The ultimate goal is to transfer the most-promising electrochemical technologies to the private sector or to another DOE program (e.g., SNL's Electric Vehicle Advanced Battery Systems Development Program, EVABS) for further development and scale-up. Besides LBL, which has overall responsibility for the ETR Program, LANL and BNL have participated in the ETR Program by providing key research support in several of the program elements. The ETR Program consists of three major elements: Exploratory Research; Applied Science Research; and Air Systems Research. The objectives and the specific battery and electrochemical systems addressed by each program element are discussed in the following sections, which also include technical summaries that relate to the individual programs. Financial information that relates to the various programs and a description of the management activities for the ETR Program are described in the Executive Summary.

  2. Exploratory technology research program for electrochemical energy storage

    NASA Astrophysics Data System (ADS)

    Kinoshita, K.

    1993-10-01

    This summary denotes the progress made by the Exploratory Technology Research (ETR) Program for Electrochemical Energy Storage during calendar year 1992. The primary objective of the ETR program, which is sponsored by the US Department of Energy (DOE) and managed by Lawrence Berkeley Laboratory (LBL), is to identify electrochemical technologies that can satisfy stringent performance, durability, and economic requirements for electric vehicles (EV's). The ultimate goal is to transfer the most promising electrochemical technologies to the private sector or to another DOE program (e.g., SNL's Electric Vehicle Advanced Battery Systems Development Program, EVABS) for further development and scale-up. Besides LBL, which has overall responsibility for the ETR program, LANL and BNL have participated in the ETR program by providing key research support in several of the program elements. Program consists of three major elements: exploratory eesearch; applied science research; and air systems research. The objectives and the specific battery and electrochemical systems addressed by each program element are discussed. Financial information that relates to the various programs and a description of the management activities for the ETR Program are described.

  3. Experiences with an Outdoor Prop Box: Addressing Standards during Recess

    ERIC Educational Resources Information Center

    Hanvey, Celeste Elaine

    2010-01-01

    When educators take play out of schools, children learn to separate play from learning. In reality, children access learning "through" play. Despite research efforts to promote the academic, physical, and cognitive importance of play in the lives of children, some school systems have reduced or eliminated playtime for young children. In…

  4. Experiences of Australian School Staff in Addressing Student Cannabis Use

    ERIC Educational Resources Information Center

    Gates, Peter J.; Norberg, Melissa M.; Dillon, Paul; Manocha, Ramesh

    2013-01-01

    Cannabis is the most frequently used illicit drug by Australian secondary school students yet there is scant research investigating school staff responses to student cannabis use. As such, this study surveyed 1,692 school staff who attended "Generation Next" seminars throughout Australia. The self-complete survey identified that the…

  5. Addressing Pedagogical Dilemmas in a Constructivist Language Learning Experience

    ERIC Educational Resources Information Center

    Nikitina, Larisa

    2010-01-01

    Educational constructivism has long been associated with advanced pedagogy on the basis that, it champions a learner-centered approach to teaching, advocates learning in meaningful contexts and promotes problem-based activities where learners construct their knowledge through interaction with their peers. Involving language learners in video…

  6. Novel nanoarchitectures for electrochemical biosensing

    NASA Astrophysics Data System (ADS)

    Archibald, Michelle M.

    Sensitive, real-time detection of biomarkers is of critical importance for rapid and accurate diagnosis of disease for point-of-care (POC) technologies. Current methods, while sensitive, do not adequately allow for POC applications due to several limitations, including complex instrumentation, high reagent consumption, and cost. We have investigated two novel nanoarchitectures, the nanocoax and the nanodendrite, as electrochemical biosensors towards the POC detection of infectious disease biomarkers to overcome these limitations. The nanocoax architecture is composed of vertically-oriented, nanoscale coaxial electrodes, with coax cores and shields serving as integrated working and counter electrodes, respectively. The dendritic structure consists of metallic nanocrystals extending from the working electrode, increasing sensor surface area. Nanocoaxial- and nanodendritic-based electrochemical sensors were fabricated and developed for the detection of bacterial toxins using an electrochemical enzyme-linked immunosorbent assay (ELISA) and differential pulse voltammetry (DPV). Proof-of-concept was demonstrated for the detection of cholera toxin (CT). Both nanoarchitectures exhibited levels of sensitivity that are comparable to the standard optical ELISA used widely in clinical applications. In addition to matching the detection profile of the standard ELISA, these electrochemical nanosensors provide a simple electrochemical readout and a miniaturized platform with multiplexing capabilities toward POC implementation. Further development as suggested in this thesis may lead to increases in sensitivity, enhancing the attractiveness of the architectures for future POC devices.

  7. Electrochemical behaviour of iron in a third-generation ionic liquid: cyclic voltammetry and micromachining investigations.

    PubMed

    Moustafa, Essam M; Mann, Olivier; Fürbeth, Wolfram; Schuster, Rolf

    2009-12-07

    The electrochemical behaviour of Fe in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim](+)Ntf2(-)) and mixtures with Cl(-) is studied with the aim of investigating the applicability of ionic liquids (IL) for the electrochemical machining of iron. Whereas in pure IL iron could not be significantly dissolved, the addition of Cl(-) enables the active dissolution with anodic current densities up to several mA cm(-2). Although several anodic peaks appear in the cyclic voltammograms (CV), the distinct assignment of those electrochemical processes remain difficult. In particular no proof for the formation of FeCl(x) (2-x) complexes during Fe dissolution are deduced from the CV, although such complexes are shown to be stable in the employed electrolyte. In addition, we present electrochemical drilling experiments with short potential pulses, which demonstrate that electrochemical machining of Fe is, in principle, possible in IL based electrolytes, even though hampered by slow machining speed.

  8. Individually addressable microelectrode arrays fabricated with gold-coated pencil graphite particles for multiplexed and high sensitive impedance immunoassays.

    PubMed

    Zhang, Yun; Wang, Hua; Nie, Jinfang; Zhang, Yuwei; Shen, Guoli; Yu, Ruqin

    2009-09-15

    A renewable, site-selective immobilization platform of microelectrode array (MEA) for multiplexed immunoassays has been initially developed using pencil graphite particles coated with gold layers as microelectrodes. The graphite particles available on the common pencil were utilized for directing the electro-deposition of gold layers with uniform microstructures which displayed a well-defined sigmoidal voltammetric response. In the concept-of-proof experiments, the resulting MEA platform was modified with functionalized monolayer, on which anti-human IgG antibodies could be stably immobilized in a site-selective way through binding chemistry to selectively capture human IgG antigens from the sample media. The subsequent introduction of anti-human IgG antibodies conjugated with 15 nm electro-active gold nanoparticles to recognize the captured IgG proteins resulted in a significant decrease in the interfacial electron-transfer resistance. High sensitive electrochemical quantification by gold nanoparticle-amplified impedance responses could thus be achieved. Experimental results show that the developed MEA sensor can allow for the detection of human IgG with wide linear range (0.05-100 ng ml(-1)) and sensitivity over 10(3) larger than that of the conventional, bulk gold electrode. The rapid regeneration of the used MEA platform can additionally be realized by a simple electrochemical treatment. The high selectivity of four individually addressable MEA platforms for multiple antigens in a single sample has been further demonstrated in the multiplexed immunoassay experiments. Such a site-selective immobilization strategy of MEA platform may open a new door towards the development of various simple, sensitive, cost-effective, and reusable biological sensors and biochips.

  9. A region addresses patient safety.

    PubMed

    Feinstein, Karen Wolk; Grunden, Naida; Harrison, Edward I

    2002-06-01

    The Pittsburgh Regional Healthcare Initiative (PRHI) is a coalition of 35 hospitals, 4 major insurers, more than 30 major and small-business health care purchasers, dozens of corporate and civic leaders, organized labor, and partnerships with state and federal government all working together to deliver perfect patient care throughout Southwestern Pennsylvania. PRHI believes that in pursuing perfection, many of the challenges facing today's health care delivery system (eg, waste and error in the delivery of care, rising costs, frustration and shortage among clinicians and workers, financial distress, overcapacity, and lack of access to care) will be addressed. PRHI has identified patient safety (nosocomial infections and medication errors) and 5 clinical areas (obstetrics, orthopedic surgery, cardiac surgery, depression, and diabetes) as ideal starting points. In each of these areas of work, PRHI partners have assembled multifacility/multidisciplinary groups charged with defining perfection, establishing region-wide reporting systems, and devising and implementing recommended improvement strategies and interventions. Many design and conceptual elements of the PRHI strategy are adapted from the Toyota Production System and its Pittsburgh derivative, the Alcoa Business System. PRHI is in the proof-of-concept phase of development.

  10. Distance effects in electrochemical micromachining

    PubMed Central

    Xu, Lizhong; Pan, Yue; Zhao, Chuanjun

    2016-01-01

    Considering exponential dependence of currents on double-layer voltage and the feedback effect of the electrolyte resistance, a distance effect in electrochemical micromachining is found, namely that both time constant and double-layer voltage depend on the separation of electrodes. The double-layer voltage is the real voltage used in processing. Under DC voltage, the apparent voltages between two electrodes are constant for different separations, but the real voltages change with the separations. Small separations exert substantial effects on the real voltages. Accordingly, a DC-voltage small-separation electrochemical micromachining technique was proposed. The double-layer voltage drops sharply as the small separation increases. Thus, the electrochemical reactions are confined to electrode regions in very close proximity even under DC voltage. The machining precision can be significantly enhanced by reducing the voltage and separation between electrodes. With this technique, the machining of conducting materials with submicrometre precision was achieved. PMID:27581708

  11. Space Electrochemical Research and Technology

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This document contains the proceedings of NASA's fourth Space Electrochemical Research and Technology (SERT) Conference, held at the NASA Lewis Research Center on April 14-15, 1993. The objective of the conference was to assess the present status and general thrust of research and development in those areas of electrochemical technology required to enable NASA missions into the next century. The conference provided a forum for the exchange of ideas and opinions of those actively involved in the field, in order to define new opportunities for the application of electrochemical processes in future NASA missions. Papers were presented in three technical areas: advanced secondary batteries, fuel cells, and advanced concepts for space power. This document contains the papers presented.

  12. Apoptosis Evaluation by Electrochemical Techniques.

    PubMed

    Yin, Jian; Miao, Peng

    2016-03-04

    Apoptosis has close relevance to pathology, pharmacology, and toxicology. Accurate and convenient detection of apoptosis would be beneficial for biological study, clinical diagnosis, and drug development. Based on distinct features of apoptotic cells, a diversity of analytical techniques have been exploited for sensitive analysis of apoptosis, such as surface plasmon resonance, electrochemical methods, flow cytometry, and some imaging assays. Among them, the features of simplicity, easy operation, low cost, and high sensitivity make electrochemical techniques powerful tools to investigate electron-transfer processes of in vitro biological systems. In this contribution, a general overview of current knowledge on various technical approaches for apoptosis evaluation is provided. Furthermore, recently developed electrochemical biosensors for detecting apoptotic cells and their advantages over traditional methods are summarized. One of the main considerations focuses on designing the recognition elements based on various biochemical events during apoptosis.

  13. ELECTROCHEMICAL DECHLORINATIONOF 2-CHLOROBIPHENYL IN AQUEOUS SOLUTION

    EPA Science Inventory

    This paper presents electrochemical dechlorination of 2-chlorobiphenyl (2-CI BP) in aqueous environment using palladium modified granular graphite electrodes. 2-CI BP, the PCB congener that requires the highest reduction potential, was effectively dechlorinated in electrochemical...

  14. Current status of environmental, health, and safety issues of electrochemical capacitors for advanced vehicle applications

    SciTech Connect

    Vimmerstedt, L J; Hammel, C J

    1997-04-01

    Electrochemical capacitors are a candidate for traction power assists in hybrid electric vehicles (HEVs). Other advanced automotive applications, while not the primary focus of current development efforts, are also possible. These include load leveling high-energy batteries, power conditioning electronics, electrically hated catalysts, electric power steering, and engine starter power. Higher power and longer cycle life are expected for electrochemical capacitors than for batteries. Evaluation of environmental, health, and safety (EH and S) issues of electrochemical capacitors is an essential part of the development and commercialization of electrochemical capacitors for advanced vehicles. This report provides an initial EH and S assessment. This report presents electrochemical capacitor electrochemistry, materials selection, intrinsic material hazards, mitigation of those hazards, environmental requirements, pollution control options, and shipping requirements. Most of the information available for this assessment pertains to commercial devices intended for application outside the advanced vehicle market and to experiment or prototype devices. Electrochemical capacitors for power assists in HEVs are not produced commercially now. Therefore, materials for advanced vehicle electrochemical capacitors may change, and so would the corresponding EH and S issues. Although changes are possible, this report describes issues for likely electrochemical capacitor designs.

  15. Coulometry Experiments Using Simple Electronic Devices.

    ERIC Educational Resources Information Center

    Grimsrud, Eric; Amend, John

    1979-01-01

    Two experiments are presented which help to illustrate a modular approach to electrochemical instrument design, but which are readily understandable to students with a limited electronics background. The experiments are coulometric titration and controlled potential coulometry.

  16. Presidential address, 2001. Advice to young surgeons.

    PubMed

    MacFarlane, John K

    2002-04-01

    In his 2001 presidential address to the Canadian Association of General Surgeons, the author offers advice to young surgeons, based on his lifetime experience as a surgical educator, researcher and practitioner. He offers the following samples of wisdom for young surgeons: they should be prepared for a lifetime of learning and be willing and able to adapt to new advances; they should listen to their patients as they describe their presenting complaints and not be tempted to interrupt; they should take time in an emergency situation and remember that split-second decisions can affect the patient for a lifetime; they should be willing to take advice from fellow professionals; they should take time to maintain a quality family life and take adequate time away from the workplace; they should be active be a role model in their community; and, finally, they should get involved and adopt an advocacy role in their profession.

  17. Presidential address, 2001. Advice to young surgeons

    PubMed Central

    MacFarlane, John K.

    2002-01-01

    In his 2001 presidential address to the Canadian Association of General Surgeons, the author offers advice to young surgeons, based on his lifetime experience as a surgical educator, researcher and practitioner. He offers the following samples of wisdom for young surgeons: they should be prepared for a lifetime of learning and be willing and able to adapt to new advances; they should listen to their patients as they describe their presenting complaints and not be tempted to interrupt; they should take time in an emergency situation and remember that split-second decisions can affect the patient for a lifetime; they should be willing to take advice from fellow professionals; they should take time to maintain a quality family life and take adequate time away from the workplace; they should be active be a role model in their community; and, finally, they should get involved and adopt an advocacy role in their profession. PMID:11939654

  18. Electrochemical Thin Layers in Nanostructures for Energy Storage.

    PubMed

    Noked, Malachi; Liu, Chanyuan; Hu, Junkai; Gregorczyk, Keith; Rubloff, Gary W; Lee, Sang Bok

    2016-10-18

    Conventional electrical energy storage (EES) electrodes, such as rechargeable batteries, are mostly based on composites of monolithic micrometer sized particles bound together with polymeric and conductive carbon additives and binders. The kinetic limitations of these monolithic chunks of material are inherently linked to their electrical properties, the kinetics of ion insertion through their interface and ion migration in and through the composite phase. Redox chemistry of nanostructured materials in EES systems offer vast gains in power and energy. Furthermore, due to their thin nature, ion and electron transport is dramatically increased, especially when thin heterogeneous conducting layers are employed synergistically. However, since the stability of the electrode material is dictated by the nature of the electrochemical reaction and the accompanying volumetric and interfacial changes from the perspective of overall system lifetime, research with nanostructured materials has shown often indefinite conclusions: in some cases, an increase in unwanted side-reactions due to the high surface area (bad). In other cases, results have shown significantly better handling of mechanical stress that results from lithiation/delithiation (good). Despite these mixed results, scientifically informed design of thin electrode materials, with carefully chosen architectures, is considered a promising route to address many limitations witnessed in EES systems by reducing and protecting electrodes from parasitic reactions, accommodating mechanical stress due to volumetric changes from electrochemical reactions, and optimizing charge carrier mobilities from both the "ionic" and "electronic" points of view. Furthermore, precise nanoscale control over the electrode structure can enable accurate measurement through advanced spectroscopy and microscopy techniques. This Account summarizes recent findings related to thin electrode materials synthesized by atomic layer deposition (ALD) and

  19. Fundamental Studies Connected with Electrochemical Energy Storage

    NASA Technical Reports Server (NTRS)

    Buck, E.; Sen, R.

    1974-01-01

    Papers are presented which deal with electrochemical research activities. Emphasis is placed on electrochemical energy storage devices. Topics discussed include: adsorption of dendrite inhibitors on zinc; proton discharge process; electron and protron transfer; quantum mechanical formulation of electron transfer rates; and theory of electrochemical kinetics in terms of two models of activation; thermal and electrostatic.

  20. Tracking of electrochemical impedance of batteries

    NASA Astrophysics Data System (ADS)

    Piret, H.; Granjon, P.; Guillet, N.; Cattin, V.

    2016-04-01

    This paper presents an evolutionary battery impedance estimation method, which can be easily embedded in vehicles or nomad devices. The proposed method not only allows an accurate frequency impedance estimation, but also a tracking of its temporal evolution contrary to classical electrochemical impedance spectroscopy methods. Taking into account constraints of cost and complexity, we propose to use the existing electronics of current control to perform a frequency evolutionary estimation of the electrochemical impedance. The developed method uses a simple wideband input signal, and relies on a recursive local average of Fourier transforms. The averaging is controlled by a single parameter, managing a trade-off between tracking and estimation performance. This normalized parameter allows to correctly adapt the behavior of the proposed estimator to the variations of the impedance. The advantage of the proposed method is twofold: the method is easy to embed into a simple electronic circuit, and the battery impedance estimator is evolutionary. The ability of the method to monitor the impedance over time is demonstrated on a simulator, and on a real Lithium ion battery, on which a repeatability study is carried out. The experiments reveal good tracking results, and estimation performance as accurate as the usual laboratory approaches.

  1. An address geocoding solution for Chinese cities

    NASA Astrophysics Data System (ADS)

    Zhang, Xuehu; Ma, Haoming; Li, Qi

    2006-10-01

    We introduce the challenges of address geocoding for Chinese cities and present a potential solution along with a prototype system that deal with these challenges by combining and extending current geocoding solutions developed for United States and Japan. The proposed solution starts by separating city addresses into "standard" addresses which meet a predefined address model and non-standard ones. The standard addresses are stored in a structured relational database in their normalized forms, while a selected portion of the non-standard addresses are stored as aliases to the standard addresses. An in-memory address index is then constructed from the address database and serves as the basis for real-time address matching. Test results were obtained from two trials conducted in the city Beijing. On average 80% matching rate were achieved. Possible improvements to the current design are also discussed.

  2. The significance of addressing trauma in outpatient psychiatry.

    PubMed

    Al-Saffar, S; Borgå, P; Lawoko, S; Edman, G; Hällström, T

    2004-01-01

    Establishing post-traumatic stress disorder as a psychiatric diagnosis has only marginally increased awareness of traumatic experiences. Traumas are inconsistently recorded in initial psychiatric histories and, when observed, rarely reflected in the primary diagnosis and treatment. The present study aimed to investigate if there is an association between sufficiently addressing trauma and long-term outcome and what factors affect whether trauma, according to the patient's view, is sufficiently addressed or not. Socio-demographic data, experiences of trauma and treatment, and outcome, were collected retrospectively from Arabic, Iranian, Turkish and Swedish patients, who had visited a psychiatric clinic 3-4 years earlier. Fifty-one patients whose traumatic experiences had been sufficiently addressed were compared with 39 patients who perceived that their traumas had not been addressed. Logistic regression analyses were performed to examine relationships between clinical variables and whether or not traumas had been addressed. Patients with trauma sufficiently addressed reported high confidence in staff (odds ratio, OR=7.2, p<0.001), high self-rated health (OR=8.0, p<0.01) and low scores on the Self-rating Inventory for PTSD (OR=7.7, p<0.05) and Depression Scale (OR=3.0, p<0.15). Reporting less than five different traumas (OR=4.6, p<0.01) and being an ethnic Swede (OR=2.4, p<0.10) were the background variables independently related to having trauma sufficiently addressed. Addressing trauma may improve patients' confidence in staff, self-rated health and trauma-related symptoms. Multiplicity of traumas and belonging to an ethnic minority implied that trauma was less addressed.

  3. The role of graphene for electrochemical energy storage

    NASA Astrophysics Data System (ADS)

    Raccichini, Rinaldo; Varzi, Alberto; Passerini, Stefano; Scrosati, Bruno

    2015-03-01

    Since its first isolation in 2004, graphene has become one of the hottest topics in the field of materials science, and its highly appealing properties have led to a plethora of scientific papers. Among the many affected areas of materials science, this 'graphene fever' has influenced particularly the world of electrochemical energy-storage devices. Despite widespread enthusiasm, it is not yet clear whether graphene could really lead to progress in the field. Here we discuss the most recent applications of graphene -- both as an active material and as an inactive component -- from lithium-ion batteries and electrochemical capacitors to emerging technologies such as metal-air and magnesium-ion batteries. By critically analysing state-of-the-art technologies, we aim to address the benefits and issues of graphene-based materials, as well as outline the most promising results and applications so far.

  4. The role of graphene for electrochemical energy storage.

    PubMed

    Raccichini, Rinaldo; Varzi, Alberto; Passerini, Stefano; Scrosati, Bruno

    2015-03-01

    Since its first isolation in 2004, graphene has become one of the hottest topics in the field of materials science, and its highly appealing properties have led to a plethora of scientific papers. Among the many affected areas of materials science, this 'graphene fever' has influenced particularly the world of electrochemical energy-storage devices. Despite widespread enthusiasm, it is not yet clear whether graphene could really lead to progress in the field. Here we discuss the most recent applications of graphene - both as an active material and as an inactive component - from lithium-ion batteries and electrochemical capacitors to emerging technologies such as metal-air and magnesium-ion batteries. By critically analysing state-of-the-art technologies, we aim to address the benefits and issues of graphene-based materials, as well as outline the most promising results and applications so far.

  5. Advanced Proton Conducting Polymer Electrolytes for Electrochemical Capacitors

    NASA Astrophysics Data System (ADS)

    Gao, Han

    Research on solid electrochemical energy storage devices aims to provide high performance, low cost, and safe operation solutions for emerging applications from flexible consumer electronics to microelectronics. Polymer electrolytes, minimizing device sealing and liquid electrolyte leakage, are key enablers for these next-generation technologies. In this thesis, a novel proton-conducing polymer electrolyte system has been developed using heteropolyacids (HPAs) and polyvinyl alcohol for electrochemical capacitors. A thorough understanding of proton conduction mechanisms of HPAs together with the interactions among HPAs, additives, and polymer framework has been developed. Structure and chemical bonding of the electrolytes have been studied extensively to identify and elucidate key attributes affecting the electrolyte properties. Numerical models describing the proton conduction mechanism have been applied to differentiate those attributes. The performance optimization of the polymer electrolytes through additives, polymer structural modifications, and synthesis of alternative HPAs has achieved several important milestones, including: (a) high proton mobility and proton density; (b) good ion accessibility at electrode/electrolyte interface; (c) wide electrochemical stability window; and (d) good environmental stability. Specifically, high proton mobility has been addressed by cross-linking the polymer framework to improve the water storage capability at normal-to-high humidity conditions (e.g. 50-80% RH) as well as by incorporating nano-fillers to enhance the water retention at normal humidity levels (e.g. 30-60% RH). High proton density has been reached by utilizing additional proton donors (i.e. acidic plasticizers) and by developing different HPAs. Good ion accessibility has been achieved through addition of plasticizers. Electrochemical stability window of the electrolyte system has also been investigated and expanded by utilizing HPAs with different heteroatoms

  6. Electrochemical Machining Removes Deep Obstructions

    NASA Technical Reports Server (NTRS)

    Catania, Mark J.

    1987-01-01

    Electrochemical machining (ECM) is effective way of removing obstructing material between two deep holes supposed to intersect but do not because of misalignment of drilling tools. ECM makes it possible to rework costly castings otherwise scrapped. Method fast even for tough or hard alloys and complicated three-dimensional shapes.

  7. [Electrochemical immunoanalysis of cardiac myoglobin].

    PubMed

    Shumiantseva, V V; Bulko, T V; Vagin, M Iu; Suprun, E V; Archakov, A I

    2010-01-01

    Method targeting the direct monitoring of myoglobin based on analysis of electrochemical parameters of modified electrodes were proposed. Method of direct detection is based on interaction of myoglobin with anti-myoglobin with subsequent electrochemical registration of hemeprotein. Myocardial infarction biomarker myoglobin was quantified at biological level using screen printed electrodes modified with gold nanoparticles stabilized with didodecyldimethylammonium bromide (DDAB) and antibodies. Proposed method did not require signal enhancement and amplification and also labeled secondary antibodies. Electro analysis has high specificity and sensitivity. Myoglobin -antibodies interaction was studied also with electrochemical impedance spectroscopy. Sensor has low detection limit and broad diapason of working concentrations (17.8 ng/ml-1780 ng/ml; 1 nM-10 nM). Method based on gold nanoparticles detection on the surface of electrodes was treated for myoglobin identification. AuNP worked as an electrochemical sensing platform: the oxidation of gold surface (resulted in gold oxide formation) upon polarization served as a basis for analytical response. The difference of cathodic peak area and peak high of gold oxide reduction in the case of electrodes with antibodies and electrodes with antibodies-myoglobin complex, was registered.

  8. Separator material for electrochemical cells

    DOEpatents

    Cieslak, Wendy R.; Storz, Leonard J.

    1991-01-01

    An electrochemical cell characterized as utilizing an aramid fiber as a separator material. The aramid fibers are especially suited for lithium/thionyl chloride battery systems. The battery separator made of aramid fibers possesses superior mechanical strength, chemical resistance, and is flame retardant.

  9. Recognized Leader in Electrochemical Purification

    ScienceCinema

    Hoppe, Eric

    2016-07-12

    PNNL scientists developed an electrochemical method for purifying copper, a key material that makes possible radiation detection systems of unprecedented sensitivity. The method begins with the purest copper materials available, and results in the lowest-background copper in the world. Chemist Eric Hoppe explains the process.

  10. Separator material for electrochemical cells

    DOEpatents

    Cieslak, W.R.; Storz, L.J.

    1991-03-26

    An electrochemical cell is characterized as utilizing an aramid fiber as a separator material. The aramid fibers are especially suited for lithium/thionyl chloride battery systems. The battery separator made of aramid fibers possesses superior mechanical strength, chemical resistance, and is flame retardant.

  11. Electrochemical Design of Optical Nanoantennas

    NASA Astrophysics Data System (ADS)

    Vasilchenko, V. E.; Kharintsev, S. S.; Salakhov, M. Kh.

    2015-09-01

    Electrochemical techniques for fabricating tapered gold nanoantennas (tips) are discussed. In the paper, the tunable design of nanoantennas is demonstrated. Tip parameters such as a tip apex curvature, mesoscopic morphology, aspect ratio and enhancement factor can be varied with etching electrolyte and applied voltage. The low-cost method makes tipehnahced optical spectroscopy and microscopy feasible for routine optical measurements beyond the diffraction limit.

  12. Electrochemical cell with calcium anode

    DOEpatents

    Cooper, John F.; Hosmer, Pamela K.; Kelly, Benjamin E.

    1979-01-01

    An electrochemical cell comprising a calcium anode and a suitable cathode in an alkaline electrolyte consisting essentially of an aqueous solution of an hydroxide and a chloride. Specifically disclosed is a mechanically rechargeable calcium/air fuel cell with an aqueous NaOH/NaCl electrolyte.

  13. Thin Film Inorganic Electrochemical Systems.

    DTIC Science & Technology

    1995-07-01

    determined that thin film cathodes of LiCoO2 can be readily performed by either spray pyrolysis or spin coating . These cathodes are electrochemically...active. We have also determined that thin film anodes of Li4Ti5O12 can be prepared by spray pyrolysis or spin coating . These anodes are also

  14. Electrochemical processing of solid waste

    NASA Technical Reports Server (NTRS)

    Bockris, John OM.

    1987-01-01

    An investigation of electrochemical waste treatment methods suitable for closed, or partially closed, life support systems for manned space exploration is discussed. The technique being investigated involves the electrolysis of solid waste where the aim is to upgrade waste material (mainly fecal waste) to generate gases that can be recycled in a space station or planetary space environment.

  15. Recognized Leader in Electrochemical Purification

    SciTech Connect

    Hoppe, Eric

    2013-11-20

    PNNL scientists developed an electrochemical method for purifying copper, a key material that makes possible radiation detection systems of unprecedented sensitivity. The method begins with the purest copper materials available, and results in the lowest-background copper in the world. Chemist Eric Hoppe explains the process.

  16. Sheet electrode for electrochemical systems

    DOEpatents

    Tsien, Hsue C.; Newby, Kenneth R.; Grimes, Patrick G.; Bellows, Richard J.

    1983-04-12

    An electrochemical cell construction features a novel co-extruded plastic electrode in an interleaved construction with a novel integral separator-spacer. Also featured is a leak and impact resistant construction for preventing the spill of corrosive materials in the event of rupture.

  17. Advances in electrospun carbon fiber-based electrochemical sensing platforms for bioanalytical applications.

    PubMed

    Mao, Xianwen; Tian, Wenda; Hatton, T Alan; Rutledge, Gregory C

    2016-02-01

    Electrochemical sensing is an efficient and inexpensive method for detection of a range of chemicals of biological, clinical, and environmental interest. Carbon materials-based electrodes are commonly employed for the development of electrochemical sensors because of their low cost, biocompatibility, and facile electron transfer kinetics. Electrospun carbon fibers (ECFs), prepared by electrospinning of a polymeric precursor and subsequent thermal treatment, have emerged as promising carbon systems for biosensing applications since the electrochemical properties of these carbon fibers can be easily modified by processing conditions and post-treatment. This review addresses recent progress in the use of ECFs for sensor fabrication and analyte detection. We focus on the modification strategies of ECFs and identification of the key components that impart the bioelectroanalytical activities, and point out the future challenges that must be addressed in order to advance the fundamental understanding of the ECF electrochemistry and to realize the practical applications of ECF-based sensing devices.

  18. Electrochemically adsorbed Pb on Ag (111) studied with grazing- incidence x-ray scattering

    SciTech Connect

    Kortright, J.B.; Ross, P.N.; Melroy, O.R.; Toney, M.F.; Borges, G.L.; Samant, M.G.

    1989-04-01

    Grazing-incidence x-ray scattering studies of the evolution of electrochemically deposited layers of lead on silver (111) as a function of applied electrochemical potential are presented. Measurements were made with the adsorbed layers in contact with solution in a specially designed sample cell. The observed lead structures are a function of the applied potential and range from an incommensurate monolayer, resulting from underpotential deposition, to randomly oriented polycrystalline bulk lead, resulting from lower deposition potentials. These early experiments demonstrate the ability of in situ x-ray diffraction measurements to determine structures associated with electrochemical deposition. 6 refs., 4 figs.

  19. Electrochemical Techniques for Intercalation Electrode Materials in Rechargeable Batteries.

    PubMed

    Zhu, Yujie; Gao, Tao; Fan, Xiulin; Han, Fudong; Wang, Chunsheng

    2017-03-16

    principles of the aforementioned four electrochemical techniques and the corresponding analytical equations for calculating the chemical diffusion coefficients are first briefly summarized, followed by a discussion of the hidden assumptions for deriving these analytical equations and the resulting limitations in their implementation. To address these limitations, various corrections have been made in the literature. Nevertheless, the phase transition behavior, which is the typical feature for many intercalation materials, is barely considered. Here we retrospect our previous work on developing a two-phase model for describing the phase transition behavior of some intercalation compounds and discuss how to obtain the chemical diffusion coefficients based on the model, using LiFePO4 as an example material. After that, we have a discussion on the methodology for using electrochemical techniques to investigate new material features. It is our hope that this Account can serve as a call for more endeavors into the development of novel electrochemical tools for battery research.

  20. Substance misuse prevention: addressing anhedonia.

    PubMed

    Sussman, Steve; Leventhal, Adam

    2014-01-01

    Anhedonia refers to the inability of experiencing pleasure in positive life events. It has been conceptualized as a stable yet malleable characteristic and is associated with hypoactivity in the mesolimbic and mesocortical dopaminergic systems. Very recently, it has been posited as an etiologic factor associated with drug addiction onset, escalation, and relapse. Prevention programming could be developed to counteract the harmful impact of anhedonia, so as to minimize its impact on drug misuse. Remedial efforts are those that either (1) permit the individual to tolerate low levels of pleasure without resorting to drug misuse or other maladaptive behaviors that may unhealthily besot pleasure (for example, through normalization, structuring time, or meditation) or (2) counteract anhedonia by enhancing ones capability to experience pleasure (for example, behavioral activation, positive psychology, pharmacotherapy, or pursuit of positive addictions). School-based activities could be developed that can be completed by individuals, small workgroups, or the whole classroom. The concept of anhedonia is described in this chapter, and possible prevention strategies that might be utilized in schools as well as other contexts are discussed.

  1. GEOSS: Addressing Big Data Challenges

    NASA Astrophysics Data System (ADS)

    Nativi, S.; Craglia, M.; Ochiai, O.

    2014-12-01

    In the sector of Earth Observation, the explosion of data is due to many factors including: new satellite constellations, the increased capabilities of sensor technologies, social media, crowdsourcing, and the need for multidisciplinary and collaborative research to face Global Changes. In this area, there are many expectations and concerns about Big Data. Vendors have attempted to use this term for their commercial purposes. It is necessary to understand whether Big Data is a radical shift or an incremental change for the existing digital infrastructures. This presentation tries to explore and discuss the impact of Big Data challenges and new capabilities on the Global Earth Observation System of Systems (GEOSS) and particularly on its common digital infrastructure called GCI. GEOSS is a global and flexible network of content providers allowing decision makers to access an extraordinary range of data and information at their desk. The impact of the Big Data dimensionalities (commonly known as 'V' axes: volume, variety, velocity, veracity, visualization) on GEOSS is discussed. The main solutions and experimentation developed by GEOSS along these axes are introduced and analyzed. GEOSS is a pioneering framework for global and multidisciplinary data sharing in the Earth Observation realm; its experience on Big Data is valuable for the many lessons learned.

  2. Programmatic methods for addressing contaminated volume uncertainties.

    SciTech Connect

    DURHAM, L.A.; JOHNSON, R.L.; RIEMAN, C.R.; SPECTOR, H.L.; Environmental Science Division; U.S. ARMY CORPS OF ENGINEERS BUFFALO DISTRICT

    2007-01-01

    Accurate estimates of the volumes of contaminated soils or sediments are critical to effective program planning and to successfully designing and implementing remedial actions. Unfortunately, data available to support the preremedial design are often sparse and insufficient for accurately estimating contaminated soil volumes, resulting in significant uncertainty associated with these volume estimates. The uncertainty in the soil volume estimates significantly contributes to the uncertainty in the overall project cost estimates, especially since excavation and off-site disposal are the primary cost items in soil remedial action projects. The Army Corps of Engineers Buffalo District's experience has been that historical contaminated soil volume estimates developed under the Formerly Utilized Sites Remedial Action Program (FUSRAP) often underestimated the actual volume of subsurface contaminated soils requiring excavation during the course of a remedial activity. In response, the Buffalo District has adopted a variety of programmatic methods for addressing contaminated volume uncertainties. These include developing final status survey protocols prior to remedial design, explicitly estimating the uncertainty associated with volume estimates, investing in predesign data collection to reduce volume uncertainties, and incorporating dynamic work strategies and real-time analytics in predesign characterization and remediation activities. This paper describes some of these experiences in greater detail, drawing from the knowledge gained at Ashland1, Ashland2, Linde, and Rattlesnake Creek. In the case of Rattlesnake Creek, these approaches provided the Buffalo District with an accurate predesign contaminated volume estimate and resulted in one of the first successful FUSRAP fixed-price remediation contracts for the Buffalo District.

  3. Electrochemical control of pH in a hydroponic nutrient solution

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, S. H.

    1986-01-01

    The electrochemical pH control system described was found to provide a feasible alternative method of controlling nutrient solution pH for CELSS applications. The plants grown in nutrient solution in which the pH was controlled electrochemically showed no adverse effects. Further research into the design of a larger capacity electrode bridge for better control is indicated by the results of this experiment, and is currently under way.

  4. Electro-deposition of Cu studied with in situ electrochemical scanning transmission x-ray microscopy

    NASA Astrophysics Data System (ADS)

    Hitchcock, A. P.; Qin, Z.; Rosendahl, S. M.; Lee, V.; Reynolds, M.; Hosseinkhannazer, H.

    2016-01-01

    Soft X-ray scanning transmission X-ray microscopy (STXM) was used to investigate Cu deposition onto, and stripping from a Au surface. Cu 2p spectromicroscopy was used to analyze initial and final states (ex situ processing) and follow the processes in situ. The in situ experiments were carried out using a static electrochemical cell with an electrolyte layer thickness of ˜1 μm. A new apparatus for in situ electrochemical STXM is described.

  5. Electrochemical synthesis of nanostructured materials for electrochemical energy conversion and storage.

    PubMed

    Li, Gao-Ren; Xu, Han; Lu, Xue-Feng; Feng, Jin-Xian; Tong, Ye-Xiang; Su, Cheng-Yong

    2013-05-21

    Electrochemical synthesis represents a highly efficient method for the fabrication of nanostructured energy materials, and various nanostructures, such as nanorods, nanowires, nanotubes, nanosheets, dendritic nanostructures, and composite nanostructures, can be easily fabricated with advantages of low cost, low synthetic temperature, high purity, simplicity, and environmental friendliness. The electrochemical synthesis, characterization, and application of electrochemical energy nanomaterials have advanced greatly in the past few decades, allowing an increasing understanding of nanostructure-property-performance relationships. Herein, we highlight some recent progress in the electrochemical synthesis of electrochemical energy materials with the assistance of additives and templates in solution or grafted onto metal or conductive polymer supports, with special attention to the effects on surface morphologies, structures and, more importantly, electrochemical performance. The methodology for preparing novel electrochemical energy nanomaterials and their potential applications has been summarized. Finally, we outline our personal perspectives on the electrochemical synthesis and applications of electrochemical energy nanomaterials.

  6. Stabilization of the initial electrochemical potential for a metal-based potentiometric titration study of a biosorption process.

    PubMed

    Naja, Ghinwa; Mustin, Christian; Volesky, Bohumil; Berthelin, Jacques

    2006-01-01

    An interactive metal-based potentiometric titration method has been developed using an ion selective electrode for studying the sorption of metal cations. The accuracy of this technique was verified by analyzing the metal sorption mechanism for the biomass of Rhizopus arrhizus fungus and diatomite, two dissimilar materials (organic and mineral, strong sorbent and weak sorbent) of a different order of cation exchange capacity. The problem of the initial electrochemical potential was addressed identifying the usefulness of a Na-sulfonic resin as a strong chelating agent applied before the beginning of sorption titration experiments so that the titration curves and the sorption uptake could be quantitatively compared. The resin stabilized the initial electrochemical potential to -405+/-5 mV corresponding to 2 micro gl(-1) of lead concentration in solution. The amounts of lead sorbed by R. arrhizus biomass and diatomite were 0.9 mmol g(-1) (C(e)=5.16 x 10(-2)mM) and 0.052 mmol g(-1) (C(e)=5.97 x 10(-2) mM), respectively. Lead sorption by the fungal biomass was pinpointed to at least two types of chemical active sites. The first type was distinguished by high reactivity and a low number of sites whereas the other was characterized by their higher number and lower reactivity.

  7. Detection of Chlamydia trachomatis by electrochemical impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Zheng, Linan

    Chlamydia trachomatis is detected by electrochemical impedance spectroscopy using a mouse monoclonal IgG2a anti-MOMP antibody immobilized onto a Si electrode. Two types of electrochemical cells are used in this study, one with the electrode at the bottom and the other will the electrode on the side. Control experiments with Escherichia coli demonstrate this biosensor is not selective to Chlamydia trachomatis. Another control experiment with Chlamydia trachomatis immobilized onto mouse monoclonal IgG2a isotype antibody coated electrode obtains an increased charge transfer resistance (Rct) which is inversely proportional to the rate of electron transfer. These results demonstrate further investigations are needed to develop the Chlamydia trachomatis impedance biosensor.

  8. A compact analytical formalism for current transients in electrochemical systems.

    PubMed

    Nair, Pradeep R; Alam, Muhammad A

    2013-01-21

    Micro- and nanostructured electrodes form an integral part of a wide variety of electrochemical systems for biomolecular detection, batteries, solar cells, scanning electrochemical microscopy, etc. Given the complexity of the electrode structures, the Butler-Volmer formalism of redox reactions, and the diffusion transport of redox species, it is hardly surprising that only a few problems are amenable to closed-form, compact analytical solutions. While numerical solutions are widely used, it is often difficult to integrate the insights gained into the design and optimization of electrochemical systems. In this article, we develop a comprehensive analytical formalism for current transients that not only anticipate the responses of complex electrode structures to complicated voltammetry measurements, but also intuitively interpret diverse experiments such as redox detection of molecules at nanogap electrodes, scanning electrochemical microscopy, etc. The results from the analytical model, well supported through detailed numerical simulations and experimental data from the literature, have broad implications in the design and optimization of nanostructured electrodes for healthcare and energy storage applications.

  9. Electrochemical advanced oxidation processes: today and tomorrow. A review.

    PubMed

    Sirés, Ignasi; Brillas, Enric; Oturan, Mehmet A; Rodrigo, Manuel A; Panizza, Marco

    2014-01-01

    In recent years, new advanced oxidation processes based on the electrochemical technology, the so-called electrochemical advanced oxidation processes (EAOPs), have been developed for the prevention and remediation of environmental pollution, especially focusing on water streams. These methods are based on the electrochemical generation of a very powerful oxidizing agent, such as the hydroxyl radical ((•)OH) in solution, which is then able to destroy organics up to their mineralization. EAOPs include heterogeneous processes like anodic oxidation and photoelectrocatalysis methods, in which (•)OH are generated at the anode surface either electrochemically or photochemically, and homogeneous processes like electro-Fenton, photoelectro-Fenton, and sonoelectrolysis, in which (•)OH are produced in the bulk solution. This paper presents a general overview of the application of EAOPs on the removal of aqueous organic pollutants, first reviewing the most recent works and then looking to the future. A global perspective on the fundamentals and experimental setups is offered, and laboratory-scale and pilot-scale experiments are examined and discussed.

  10. SkBQ - prooxidant addressed to mitochondria.

    PubMed

    Vyssokikh, M Y; Chernyak, B V; Domnina, L V; Esipov, D S; Ivanova, O Y; Korshunova, G A; Symonyan, R A; Skulachev, M V; Zinevich, T V; Skulachev, V P

    2013-12-01

    Oxidative stress and mitochondrial dysfunction are the key links in the chain of development of pathologies associated with the violation of cellular energy metabolism. Development of mitochondria-addressed compounds highly specific for chemical processes is one of the most promising ways to develop approaches to the treatment of inherited and age-related diseases with mitochondrial etiology. Correlation of structure and chemical activity of the test compounds from a class of lipophilic cations revealed the key role of substituents in the aromatic ring of 1,4-benzoquinones in the manifestation of high antioxidant properties. In this work, it is shown that a synthesized benzoquinone derivative conjugated in position 6 with membrane-penetrating cation of decyltriphenylphosphonium and with substituents at position 2, 3, and 5 (SkBQ) has much lower antioxidant and significantly higher prooxidant activity in comparison with similar derivatives of plasto- and toluquinone SkQ1 and SkQT1 in experiments on isolated mitochondria. At the same time, SkBQ, like SkQ1 and SkQT1, can be reduced by the respiratory chain in the center i of complex III and decrease the mitochondrial membrane potential. In cell cultures of human fibroblasts, it was revealed that SkBQ does not protect cells from apoptosis induced by hydrogen peroxide. Under the same conditions, SkQ1 and SkQT1 exhibit a powerful protective effect. Thus, SkBQ can be seen as a mitochondria-addressed prooxidant. The possibility of using SkBQ as an anticancer drug for the treatment of cancers such as prostate cancer whose cells are sensitive to mitochondrial reactive oxygen species is discussed.

  11. Integrated optical addressing of an ion qubit

    NASA Astrophysics Data System (ADS)

    Mehta, Karan K.; Bruzewicz, Colin D.; McConnell, Robert; Ram, Rajeev J.; Sage, Jeremy M.; Chiaverini, John

    2016-12-01

    The long coherence times and strong Coulomb interactions afforded by trapped ion qubits have enabled realizations of the necessary primitives for quantum information processing and the highest-fidelity quantum operations in any qubit to date. Although light delivery to each individual ion in a system is essential for general quantum manipulations and readout, experiments so far have employed optical systems that are cumbersome to scale to even a few tens of qubits. Here we demonstrate lithographically defined nanophotonic waveguide devices for light routing and ion addressing that are fully integrated within a surface-electrode ion trap chip. Ion qubits are addressed at multiple locations via focusing grating couplers emitting through openings in the trap electrodes to ions trapped 50 μm above the chip; using this light, we perform quantum coherent operations on the optical qubit transition in individual 88Sr+ ions. The grating focuses the beam to a diffraction-limited spot near the ion position with 2 μm 1/e2 radius along the trap axis, and we measure crosstalk errors between 10-2 and 4 × 10-4 at distances 7.5-15 μm from the beam centre. Owing to the scalability of the planar fabrication technique employed, together with the tight focusing and stable alignment afforded by the integration of the optics within the trap chip, this approach presents a path to creating the optical systems required for large-scale trapped-ion quantum information processing.

  12. 16 CFR 0.2 - Official address.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Official address. The principal office of the Commission is at Washington, DC. All communications to the Commission should be addressed to the Federal Trade Commission, 600 Pennsylvania Avenue, NW, Washington,...

  13. 16 CFR 0.2 - Official address.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Official address. The principal office of the Commission is at Washington, DC. All communications to the Commission should be addressed to the Federal Trade Commission, 600 Pennsylvania Avenue, NW, Washington,...

  14. 16 CFR 0.2 - Official address.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Official address. The principal office of the Commission is at Washington, DC. All communications to the Commission should be addressed to the Federal Trade Commission, 600 Pennsylvania Avenue, NW, Washington,...

  15. 47 CFR 97.23 - Mailing address.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Mailing address. 97.23 Section 97.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO... name and mailing address. The mailing address must be in an area where the amateur service is...

  16. 47 CFR 97.23 - Mailing address.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Mailing address. 97.23 Section 97.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO... name and mailing address. The mailing address must be in an area where the amateur service is...

  17. 47 CFR 97.23 - Mailing address.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Mailing address. 97.23 Section 97.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO... name and mailing address. The mailing address must be in an area where the amateur service is...

  18. 47 CFR 97.23 - Mailing address.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Mailing address. 97.23 Section 97.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO... name and mailing address. The mailing address must be in an area where the amateur service is...

  19. 47 CFR 97.23 - Mailing address.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Mailing address. 97.23 Section 97.23 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO... name and mailing address. The mailing address must be in an area where the amateur service is...

  20. 37 CFR 41.10 - Correspondence addresses.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Correspondence addresses. 41... Correspondence addresses. Except as the Board may otherwise direct, (a) Appeals. Correspondence in an application... correspondence in an application or a patent involved in an appeal to the Board for which an address is...

  1. 37 CFR 41.10 - Correspondence addresses.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Correspondence addresses. 41... Correspondence addresses. Except as the Board may otherwise direct, (a) Appeals. Correspondence in an application... correspondence in an application or a patent involved in an appeal to the Board for which an address is...

  2. 47 CFR 13.10 - Licensee address.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Licensee address. 13.10 Section 13.10 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL RADIO OPERATORS General § 13.10 Licensee address. In accordance with § 1.923 of this chapter all applications must specify an address where...

  3. 32 CFR 516.7 - Mailing addresses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Mailing addresses. 516.7 Section 516.7 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS LITIGATION General § 516.7 Mailing addresses. Mailing addresses for organizations referenced...

  4. Exploratory Technology Research Program for electrochemical energy storage. Annual report fr 1994

    SciTech Connect

    Kinoshita, K.

    1995-09-01

    The US Department of Energy`s Office of Propulsion Systems provides support for an Electrochemical Energy Storage Program, that includes research and development (R&D) on advanced rechargeable batteries and fuel cells. A major goal of this program is to develop electrochemical power sources suitable for application in electric vehicles (EVs). The program centers on advanced systems that offer the potential for high performance and low life-cycle costs, both of which are necessary to permit significant penetration into commercial markets. The DOE Electrochemical Energy Storage Program is divided into two projects: the Electric Vehicle Advanced Battery Systems (EVABS) Development Program and the Exploratory Technology Research (ETR) Program. The general R&D areas addressed by the program include identification of new electrochemical couples for advanced batteries, determination of technical feasibility of the new couples, improvements in battery components and materials, establishment of engineering principles applicable to electrochemical energy storage and conversion, and the development of air-system (fuel cell, metal/air) technology for transportation applications. Major emphasis is given to applied research which will lead to superior performance and lower life-cycle costs. The ETR Program is divided into three major program elements: Exploratory Research, Applied Science Research, and Air Systems Research. Highlights of each program element are summarized according to the appropriate battery system or electrochemical research area.

  5. Electrochemical promotion of catalytic reactions

    NASA Astrophysics Data System (ADS)

    Imbihl, R.

    2010-05-01

    The electrochemical promotion of heterogeneously catalyzed reactions (EPOC) became feasible through the use of porous metal electrodes interfaced to a solid electrolyte. With the O 2- conducting yttrium stabilized zirconia (YSZ), the Na + conducting β″-Al 2O 3 (β-alumina), and several other types of solid electrolytes the EPOC effect has been demonstrated for about 100 reaction systems in studies conducted mainly in the mbar range. Surface science investigations showed that the physical basis for the EPOC effect lies in the electrochemically induced spillover of oxygen and alkali metal, respectively, onto the surface of the metal electrodes. For the catalytic promotion effect general concepts and mechanistic schemes were proposed but these concepts and schemes are largely speculative. Applying surface analytical tools to EPOC systems the proposed mechanistic schemes can be verified or invalidated. This report summarizes the progress which has been achieved in the mechanistic understanding of the EPOC effect.

  6. Electrochemical corrosion of metallic biomaterials.

    PubMed

    Pourbaix, M

    1984-05-01

    Methods of electrochemical thermodynamics (electrode potential-pH equilibrium diagrams) and electrochemical kinetics (polarization curves) may help to understand and predict the corrosion behaviour of metals and alloys in the presence of body fluids. A short review of the literature is given concerning some applications of such methods, both in vitro and in vivo, relating to surgical implants (stainless steels, chromium-cobalt-molybdenum alloys, titanium and titanium alloys) and to dental alloys (silver-tin-copper amalgams, silver-base and gold-base casting alloys, nickel-base casting alloys). Attention is drawn to the necessity of more basic research on crevice- and fretting-corrosion of surgical implant materials and dental alloys, and to the toxicity of corrosion products. A perfect understanding of the exact significance of electrode-potentials is essential for the success of such a task.

  7. Electrochemical oxidation of chemical weapons

    SciTech Connect

    Surma, J.E.

    1994-05-01

    Catalyzed electrochemical oxidation (CEO), a low-temperature electrochemical oxidation technique, is being examined for its potential use in destroying chemical warfare agents. The CEO process oxidizes organic compounds to form carbon dioxide and water. A bench-scale CEO system was used in three separate tests sponsored by the US Department of Energy`s (DOE) Office of Intelligence and National Security through the Advanced Concepts Program. The tests examined the effectiveness of CEO in destroying sarin (GB), a chemical nerve agent. The tests used 0.5 mL, 0.95 mL, and 1.0 mL of GB, corresponding to 544 mg, 816 mg, and 1,090 mg, respectively, of GB. Analysis of the off gas showed that, under continuous processing of the GB agent, destruction efficiencies of better than six 9s (99.9999% destroyed) could be achieved.

  8. Electrochemical treatment of liquid wastes

    SciTech Connect

    Hobbs, D.

    1996-10-01

    Electrochemical treatment processes are being evaluated and developed for the destruction of organic compounds and nitrates/nitrites and the removal of other hazardous species from liquid wastes stored throughout the DOE complex. This activity consists of five major tasks: (1) evaluation of different electrochemical reactors for the destruction and removal of hazardous waste components, (2) development and validation of engineering process models, (3) radioactive laboratory-scale tests, (4) demonstration of the technology in an engineering-scale size reactor, and (5) analysis and evaluation of testing data. The development program team is comprised of individuals from federal, academic, and private industry. Work is being carried out in DOE, academic, and private industrial laboratories.

  9. Electrochemically driven mechanical energy harvesting

    PubMed Central

    Kim, Sangtae; Choi, Soon Ju; Zhao, Kejie; Yang, Hui; Gobbi, Giorgia; Zhang, Sulin; Li, Ju

    2016-01-01

    Efficient mechanical energy harvesters enable various wearable devices and auxiliary energy supply. Here we report a novel class of mechanical energy harvesters via stress–voltage coupling in electrochemically alloyed electrodes. The device consists of two identical Li-alloyed Si as electrodes, separated by electrolyte-soaked polymer membranes. Bending-induced asymmetric stresses generate chemical potential difference, driving lithium ion flux from the compressed to the tensed electrode to generate electrical current. Removing the bending reverses ion flux and electrical current. Our thermodynamic analysis reveals that the ideal energy-harvesting efficiency of this device is dictated by the Poisson's ratio of the electrodes. For the thin-film-based energy harvester used in this study, the device has achieved a generating capacity of 15%. The device demonstrates a practical use of stress-composition–voltage coupling in electrochemically active alloys to harvest low-grade mechanical energies from various low-frequency motions, such as everyday human activities. PMID:26733282

  10. Electrochemically driven mechanical energy harvesting.

    PubMed

    Kim, Sangtae; Choi, Soon Ju; Zhao, Kejie; Yang, Hui; Gobbi, Giorgia; Zhang, Sulin; Li, Ju

    2016-01-06

    Efficient mechanical energy harvesters enable various wearable devices and auxiliary energy supply. Here we report a novel class of mechanical energy harvesters via stress-voltage coupling in electrochemically alloyed electrodes. The device consists of two identical Li-alloyed Si as electrodes, separated by electrolyte-soaked polymer membranes. Bending-induced asymmetric stresses generate chemical potential difference, driving lithium ion flux from the compressed to the tensed electrode to generate electrical current. Removing the bending reverses ion flux and electrical current. Our thermodynamic analysis reveals that the ideal energy-harvesting efficiency of this device is dictated by the Poisson's ratio of the electrodes. For the thin-film-based energy harvester used in this study, the device has achieved a generating capacity of 15%. The device demonstrates a practical use of stress-composition-voltage coupling in electrochemically active alloys to harvest low-grade mechanical energies from various low-frequency motions, such as everyday human activities.

  11. Theory of electrochemical pattern formation

    NASA Astrophysics Data System (ADS)

    Christoph, J.; Eiswirth, M.

    2002-03-01

    The spatial coupling in electrochemical systems is mediated by ion migration under the influence of the electric field. Since field effects spread very rapidly, every point of an electrode can communicate with every other one practically instantaneously through migration coupling. Based on mathematical potential theory we present the derivation of a generally applicable reaction-migration equation, which describes the coupling via an integral over the whole electrode area. The corresponding coupling function depends only on the geometry of the electrode setup and has been computed for commonly used electrode shapes (such as ring, disk, ribbon or rectangle). The pattern formation observed in electrochemical systems in the bistable, excitable and oscillatory regime can be reproduced in computer simulations, and the types of patterns occurring under different geometries can be rationalized.

  12. Electrochemical synthesis of multisegmented nanowires

    SciTech Connect

    Kok, Kuan-Ying; Ng, Inn-Khuan; Saidin, Nur Ubaidah

    2012-11-27

    Electrochemical deposition has emerged as a promising route for nanostructure fabrication in recent years due to the many inherent advantages it possesses. This study focuses on the synthesis of high-aspect-ratio multisegmented Au/Ni nanowires using template-directed sequential electrochemical deposition techniques. By selectively removing the Ni segments in the nanowires, high-yield of pure gold nanorods of predetermined lengths was obtained. Alternatively, the sacrificial Ni segments in the nanowires can be galvanically displaced with Bi and Te to form barbells structures with Bi{sub x}Te{sub y} nanotubes attached to neighbouring gold segments. Detailed studies on the nanostructures obtained were carried out using various microscopy, diffraction and probebased techniques for structural, morphological and chemical characterizations.

  13. A Parylene Bellows Electrochemical Actuator

    PubMed Central

    Li, Po-Ying; Sheybani, Roya; Gutierrez, Christian A.; Kuo, Jonathan T. W.; Meng, Ellis

    2011-01-01

    We present the first electrochemical actuator with Parylene bellows for large-deflection operation. The bellows diaphragm was fabricated using a polyethylene-glycol-based sacrificial molding technique followed by coating in Parylene C. Bellows were mechanically characterized and integrated with a pair of interdigitated electrodes to form an electrochemical actuator that is suitable for low-power pumping of fluids. Pump performance (gas generation rate and pump efficiency) was optimized through a careful examination of geometrical factors. Overall, a maximum pump efficiency of 90% was achieved in the case of electroplated electrodes, and a deflection of over 1.5 mm was demonstrated. Real-time wireless operation was achieved. The complete fabrication process and the materials used in this actuator are bio-compatible, which makes it suitable for biological and medical applications. PMID:21318081

  14. Electrochemically driven mechanical energy harvesting

    NASA Astrophysics Data System (ADS)

    Kim, Sangtae; Choi, Soon Ju; Zhao, Kejie; Yang, Hui; Gobbi, Giorgia; Zhang, Sulin; Li, Ju

    2016-01-01

    Efficient mechanical energy harvesters enable various wearable devices and auxiliary energy supply. Here we report a novel class of mechanical energy harvesters via stress-voltage coupling in electrochemically alloyed electrodes. The device consists of two identical Li-alloyed Si as electrodes, separated by electrolyte-soaked polymer membranes. Bending-induced asymmetric stresses generate chemical potential difference, driving lithium ion flux from the compressed to the tensed electrode to generate electrical current. Removing the bending reverses ion flux and electrical current. Our thermodynamic analysis reveals that the ideal energy-harvesting efficiency of this device is dictated by the Poisson's ratio of the electrodes. For the thin-film-based energy harvester used in this study, the device has achieved a generating capacity of 15%. The device demonstrates a practical use of stress-composition-voltage coupling in electrochemically active alloys to harvest low-grade mechanical energies from various low-frequency motions, such as everyday human activities.

  15. Reviews Book: The Quantum Story: A History in 40 Moments Resource: Down2Earth Equipment: Irwin Signal Generator/Power Amplifier Book: Laboratory Experiments in Physics for Modern Astronomy Book: Heart of Darkness Book: The Long Road to Stockholm Book: The Address Book: Our Place in the Scheme of Things Equipment: TI-Nspire Datalogger/Calculator Web Watch

    NASA Astrophysics Data System (ADS)

    2013-07-01

    WE RECOMMEND The Quantum Story: A History in 40 Moments Dip into this useful and accessible guide to quantum theory Down2Earth Astronomical-science resource enables students to pursue real, hands-on science, whatever the weather Irwin Signal Generator/Power Amplifier Students enjoy the novelty factor of versatile, affordable kit Laboratory Experiments in Physics for Modern Astronomy Book of experiments would make good supplementary material Heart of Darkness: Unravelling the Mysteries of the Invisible Universe Accessible and distinctive account of cosmology impresses The Long Road to Stockholm: The Story of MRI—An Autobiography Fascinating book tells personal and scientific stories side by side WORTH A LOOK The Address Book: Our Place in the Scheme of Things Entertaining and well-written essays offer insights and anecdotes TI-Nspire Datalogger/Calculator Challenging interface gives this kit a steep learning curve, but once overcome, results are good WEB WATCH Light-beam app game leaves little impression, while astronomy and astrophysics projects provide much-needed resources

  16. Strategies to Address Common Challenges When Teaching in an Active Learning Classroom

    ERIC Educational Resources Information Center

    Petersen, Christina I.; Gorman, Kristen S.

    2014-01-01

    This chapter provides practical strategies for addressing common challenges that arise for teachers in active learning classrooms. Our strategies come from instructors with experience teaching in these environments.

  17. Cathode composition for electrochemical cell

    DOEpatents

    Steunenberg, Robert K.; Martin, Allan E.; Tomczuk, Zygmunt

    1976-01-01

    A high-temperature, secondary electrochemical cell includes a negative electrode containing an alkali metal such as lithium, an electrolyte of molten salt containing ions of that alkali metal and a positive electrode containing a mixture of metallic sulfides. The positive electrode composition is contained within a porous structure that permits permeation of molten electrolyte and includes a mixture of about 5% to 30% by weight Cu.sub.2 S in FeS.

  18. Solid state electrochemical current source

    DOEpatents

    Potanin, Alexander Arkadyevich; Vedeneev, Nikolai Ivanovich

    2002-04-30

    A cathode and a solid state electrochemical cell comprising said cathode, a solid anode and solid fluoride ion conducting electrolyte. The cathode comprises a metal oxide and a compound fluoride containing at least two metals with different valences. Representative compound fluorides include solid solutions of bismuth fluoride and potassium fluoride; and lead fluoride and potassium fluoride. Representative metal oxides include copper oxide, lead oxide, manganese oxide, vanadium oxide and silver oxide.

  19. [Electrochemical methods for biomedical investigations].

    PubMed

    Shumyantseva, V V; Bulko, T V; Suprun, E V; Kuzikov, A V; Agafonova, L E; Archakov, A I

    2015-01-01

    In the review, authors discussed recently published experimental data concerning highly sensitive electrochemical methods and technologies for biomedical investigations in the postgenomic era. Developments in electrochemical biosensors systems for the analysis of various bio objects are also considered: cytochrome P450s, cardiac markers, bacterial cells, the analysis of proteins based on electro oxidized amino acids as a tool for analysis of conformational events. The electroanalysis of catalytic activity of cytochromes P450 allowed developing system for screening of potential substrates, inhibitors or modulators of catalytic functions of this class of hemoproteins. The highly sensitive quartz crystal microbalance (QCM) immunosensor has been developed for analysis of bio affinity interactions of antibodies with troponin I in plasma. The QCM technique allowed real-time monitoring of the kinetic differences in specific interactions and nonspecific sorption, with out multiple labeling procedures and separation steps. The affinity binding process was characterized by the association (ka) and the dissociation (kd) kinetic constants and the equilibrium association (K) constant, calculated using experimental data. Based on the electroactivity of bacterial cells, the electrochemical system for determination of sensitivity of the microbial cells to antibiotics cefepime, ampicillin, amikacin, and erythromycin was proposed. It was shown that the minimally detectable cell number corresponds to 106 CFU per electrode. The electrochemical method allows estimating the degree of E.coli JM109 cells resistance to antibiotics within 2-5 h. Electrosynthesis of polymeric analogs of antibodies for myoglobin (molecularly imprinted polymer, MIP) on the surface of graphite screen-printed electrodes as sensor elements with o- phenylenediamine as the functional monomer was developed. Molecularly imprinted polymers demonstrate selective complementary binding of a template protein molecule

  20. Materials for Electrochemical Energy Storage

    NASA Astrophysics Data System (ADS)

    Johannes, Michelle

    2013-03-01

    Electrochemical energy storage is a primary concern of both the consumer and public energy sectors. Energy, once generated, must be stored, transported and retrieved efficiently. This is commonly done through the use of various kinds of batteries and recently through the use of capacitors. Optimal energy storage involves the complete electrochemical system, but many of the performance properties can be understood in terms of the constituent materials that make up the anode, cathode and electrolyte. In this talk will give a brief overview of electrochemical energy storage systems and the role of materials in improving them. Using computational methods as a framework, I will discuss how discuss how macroscopic properties, such as capacity, conductivity, voltage, and stability are determined by fundamental materials properties at the quantum mechanical level. Using the knowledge gained from understanding the underlying processes, I will discuss some common battery materials, such as LiFePO4, layered transition metal oxides, and oxide electrolyte materials. I will show how predictions for better materials can be made using computational tools to save time and money by circumventing expensive screening in the laboratory. I will also discuss how tailoring the morphology of materials, for example by synthesizing at the nanoscale, can have extreme benefits for battery materials performance.

  1. Compacted carbon for electrochemical cells

    DOEpatents

    Greinke, R.A.; Lewis, I.C.

    1997-10-14

    This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (1) an x-ray density of at least 2.00 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 47%; and (b) graphite having the following properties: (1) an x-ray density of at least 2.20 grams per cubic centimeters, (2) a closed porosity of no greater than 5%, and (3) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counter electrode. 10 figs.

  2. Compacted carbon for electrochemical cells

    DOEpatents

    Greinke, Ronald Alfred; Lewis, Irwin Charles

    1997-01-01

    This invention provides compacted carbon that is useful in the electrode of an alkali metal/carbon electrochemical cell of improved capacity selected from the group consisting of: (a) coke having the following properties: (i) an x-ray density of at least 2.00 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 47%; and (b) graphite having the following properties: (i) an x-ray density of at least 2.20 grams per cubic centimeters, (ii) a closed porosity of no greater than 5%, and (iii) an open porosity of no greater than 25%. This invention also relates to an electrode for an alkali metal/carbon electrochemical cell comprising compacted carbon as described above and a binder. This invention further provides an alkali metal/carbon electrochemical cell comprising: (a) an electrode as described above, (b) a non-aqueous electrolytic solution comprising an organic aprotic solvent and an electrolytically conductive salt and an alkali metal, and (c) a counterelectrode.

  3. Folding- and Dynamics-Based Electrochemical DNA Sensors.

    PubMed

    Lai, Rebecca Y

    2017-01-01

    A number of electrochemical DNA sensors based on the target-induced change in the conformation and/or flexibility of surface-bound oligonucleotides have been developed in recent years. These sensors, which are often termed E-DNA sensors, are comprised of an oligonucleotide probe modified with a redox label (e.g., methylene blue) at one terminus and attached to a gold electrode via a thiol-gold bond at the other. Binding of the target to the DNA probe changes its structure and dynamics, which, in turn, influences the efficiency of electron transfer to the interrogating electrode. Since electrochemically active contaminants are less common, these sensors are resistant to false-positive signals arising from the nonspecific adsorption of contaminants and perform well even when employed directly in serum, whole blood, and other realistically complex sample matrices. Moreover, because all of the sensor components are chemisorbed to the electrode, the E-DNA sensors are essentially label-free and readily reusable. To date, these sensors have achieved state-of-the-art sensitivity, while offering the unprecedented selectivity, reusability, and the operational convenience of direct electrochemical detection. This chapter reviews the recent advances in the development of both "signal-off" and "signal-on" E-DNA sensors. Critical aspects that dictate the stability and performance of these sensors are also addressed so as to provide a realistic overview of this oligonucleotide detection platform.

  4. Electrochemical study of DNA damaged by oxidation stress.

    PubMed

    Zitka, Ondrej; Krizkova, Sona; Skalickova, Sylvie; Kopel, Pavel; Babula, Petr; Adam, Vojtech; Kizek, Rene

    2013-02-01

    Many compounds can interact with DNA leading to changes of DNA structure as point mutation and bases excision, which could trigger some metabolic failures, which leads to the changes in DNA structure resulting in cancer. Oxidation of nucleic acid bases belongs to the one of the mostly occurred type of DNA damaging leading to the above mentioned phenomena. The investigation of processes of DNA oxidation damage is topical and electrochemical methods include a versatile and sensitive tool for these purposes. 8-hydroxydeoxyguanosine (8-OHdG) is the most widely accepted marker of DNA damage. Oxidative damage to DNA by free radicals and exposure to ionizing radiation generate several other products within the double helix besides mentioned oxidation products of nucleic acid bases. The basic electrochemical behaviour of nucleic acids bases on various types of carbon electrodes is reviewed. Further, we address our attention on description of oxidation mechanisms and on detection of the most important products of nucleic bases oxidation. The miniaturization of detector coupled with some microfluidic devices is suggested and discussed. The main aim of this review is to report the advantages and features of the electrochemical detection of guanine oxidation product as 8-OHdG and other similarly produced molecules as markers for DNA damage.

  5. Imaginative Thinking: Addressing Social Justice Issues through MovieMaker

    ERIC Educational Resources Information Center

    Boske, Christa A.

    2009-01-01

    Purpose: The purpose of this paper is to examine the experiences of aspiring school leaders who utilized artmaking in this case, photography, poetry, music, collage, and short films through Microsoft MovieMaker as a means for addressing injustices within surrounding school communities. The paper aims to explore how aspiring school leaders…

  6. Designing Interactive Multimedia Instruction to Address Soldiers’ Learning Needs

    DTIC Science & Technology

    2014-12-01

    learners’ experiences , background knowledge, and job-specific requirements. Here, we describe the process used and rationale for our approach to...According to Clark and Mayer (2008), these critical design features address three goals: (a) reducing extrinsic cognitive processing , (b) managing...intrinsic cognitive processing , and (c) facilitating generative processing . Table 5 summarizes the features of well-designed IMI identified by Mayer

  7. Balancing Act: Addressing Culture and Gender in ESL Classrooms

    ERIC Educational Resources Information Center

    Johnson, Michelle A.; Chang, Debbie

    2012-01-01

    ESL educators find themselves teaching a diverse group of students in today's classroom. This study investigated how ESL instructors address diversity in their teaching. The literature review revealed research on the experiences of teachers using culturally responsive teaching strategies. Using qualitative research methods, this study explores the…

  8. Spatially and Temporally Resolved Single-Cell Exocytosis Utilizing Individually Addressable Carbon Microelectrode Arrays

    PubMed Central

    Zhang, Bo; Adams, Kelly L.; Luber, Sarah J.; Eves, Daniel J.; Heien, Michael L.; Ewing, Andrew G.

    2009-01-01

    We report the fabrication and characterization of carbon microelectrode arrays (MEAs) and their application to spatially and temporally resolve neurotransmitter release from single pheochromocytoma (PC12) cells. The carbon MEAs are composed of individually addressable 2.5-μm-radius microdisks embedded in glass. The fabrication involves pulling a multibarrel glass capillary containing a single carbon fiber in each barrel into a sharp tip, followed by beveling the electrode tip to form an array (10−20 μm) of carbon microdisks. This simple fabrication procedure eliminates the need for complicated wiring of the independent electrodes, thus allowing preparation of high-density individually addressable microelectrodes. The carbon MEAs have been characterized using scanning electron microscopy, steady-state and fast-scan voltammetry, and numerical simulations. Amperometric results show that subcellular heterogeneity in single-cell exocytosis can be electrochemically detected with MEAs. These ultrasmall electrochemical probes are suitable for detecting fast chemical events in tight spaces, as well as for developing multifunctional electrochemical microsensors. PMID:18232712

  9. Computational strategies to address chromatin structure problems

    NASA Astrophysics Data System (ADS)

    Perišić, Ognjen; Schlick, Tamar

    2016-06-01

    While the genetic information is contained in double helical DNA, gene expression is a complex multilevel process that involves various functional units, from nucleosomes to fully formed chromatin fibers accompanied by a host of various chromatin binding enzymes. The chromatin fiber is a polymer composed of histone protein complexes upon which DNA wraps, like yarn upon many spools. The nature of chromatin structure has been an open question since the beginning of modern molecular biology. Many experiments have shown that the chromatin fiber is a highly dynamic entity with pronounced structural diversity that includes properties of idealized zig-zag and solenoid models, as well as other motifs. This diversity can produce a high packing ratio and thus inhibit access to a majority of the wound DNA. Despite much research, chromatin’s dynamic structure has not yet been fully described. Long stretches of chromatin fibers exhibit puzzling dynamic behavior that requires interpretation in the light of gene expression patterns in various tissue and organisms. The properties of chromatin fiber can be investigated with experimental techniques, like in vitro biochemistry, in vivo imagining, and high-throughput chromosome capture technology. Those techniques provide useful insights into the fiber’s structure and dynamics, but they are limited in resolution and scope, especially regarding compact fibers and chromosomes in the cellular milieu. Complementary but specialized modeling techniques are needed to handle large floppy polymers such as the chromatin fiber. In this review, we discuss current approaches in the chromatin structure field with an emphasis on modeling, such as molecular dynamics and coarse-grained computational approaches. Combinations of these computational techniques complement experiments and address many relevant biological problems, as we will illustrate with special focus on epigenetic modulation of chromatin structure.

  10. Programmatic methods for addressing contaminated volume uncertainties

    SciTech Connect

    Rieman, C.R.; Spector, H.L.; Durham, L.A.; Johnson, R.L.

    2007-07-01

    Accurate estimates of the volumes of contaminated soils or sediments are critical to effective program planning and to successfully designing and implementing remedial actions. Unfortunately, data available to support the pre-remedial design are often sparse and insufficient for accurately estimating contaminated soil volumes, resulting in significant uncertainty associated with these volume estimates. The uncertainty in the soil volume estimates significantly contributes to the uncertainty in the overall project cost estimates, especially since excavation and off-site disposal are the primary cost items in soil remedial action projects. The U.S. Army Corps of Engineers Buffalo District's experience has been that historical contaminated soil volume estimates developed under the Formerly Utilized Sites Remedial Action Program (FUSRAP) often underestimated the actual volume of subsurface contaminated soils requiring excavation during the course of a remedial activity. In response, the Buffalo District has adopted a variety of programmatic methods for addressing contaminated volume uncertainties. These include developing final status survey protocols prior to remedial design, explicitly estimating the uncertainty associated with volume estimates, investing in pre-design data collection to reduce volume uncertainties, and incorporating dynamic work strategies and real-time analytics in pre-design characterization and remediation activities. This paper describes some of these experiences in greater detail, drawing from the knowledge gained at Ashland 1, Ashland 2, Linde, and Rattlesnake Creek. In the case of Rattlesnake Creek, these approaches provided the Buffalo District with an accurate pre-design contaminated volume estimate and resulted in one of the first successful FUSRAP fixed-price remediation contracts for the Buffalo District. (authors)

  11. Emergency preparedness: addressing a residency training gap.

    PubMed

    Uddin, Sayeedha Ghori; Barnett, Daniel J; Parker, Cindy L; Links, Jonathan M; Alexander, Miriam

    2008-03-01

    As the importance of physician involvement and leadership in crisis preparedness is recognized, the literature suggests that few physicians are adequately trained to practice effectively in a large-scale crisis situation. A logical method for addressing the emergency preparedness training deficiency identified across several medical specialties is to include disaster and emergency preparedness training in residency curricula. In this article, the authors outline the development and implementation of an emergency preparedness curriculum for the Johns Hopkins General Preventive Medicine Residency (JHGPMR) from 2004 to 2006. The curriculum consists of two components. The first was developed for the academic year in the JHGPMR and includes didactic lectures, practical exercises to apply new knowledge, and an opportunity to integrate the knowledge and skills in a real-world exercise. The second, developed for the practicum year of the residency, includes Web-based lectures and online content and culminates in a tabletop preparedness exercise. Topics for both components include weapons of mass destruction, risk communication and personal preparedness, aspects of local emergency response planning, and mental health and psychological aspects of terrorism. On the basis of the emergency preparedness training gap that has been identified in the literature, and the success of the three-year experience in implementing a preparedness training curriculum in the JHGPMR, the authors recommend incorporation of competency-based emergency preparedness training for residencies of all specialties, and offer insights into how the described curriculum could be adapted for use in other residency settings.

  12. Electrochemical analysis of lithium polymer batteries

    NASA Astrophysics Data System (ADS)

    Han, Yong-Bong

    Lithium batteries consist of lithium anode, polymer electrolyte separator, and the porous, composite cathode. Lithium batteries have been very attractive to the battery industries because lithium metal has an extremely high energy density. The use of lithium metal can cause dendrite formation by uneven electro-deposition during charge. The lithium battery can explode in a liquid electrolyte when it is shorted by the dendrite. It has been reported that the mechanical properties of a polymer electrolyte can retard the dendrite initiation. We have attempted to study the dendrite initiation quantitatively by developing a mathematical model that evaluates the behavior of the interface and by performing dendrite-initiation experiments with the use of cross-linked polymer electrolytes to vary the mechanical properties of the electrolyte. Cross-linking the polymer backbone may decrease the transport properties of the polymer electrolyte. The transport properties are diffusion coefficient, ionic conductivity, and transference number of the electrolyte. When poor transport properties of the polymer electrolyte cause salt depletion at the cathode at low salt concentrations, side reactions and dendrite initiation can be accelerated. In order to study how cross-linking the polymer backbone affects the transport properties, the transport properties are measured experimentally by LBNL method which is based on concentrated solution theory. Porous electrodes are commonly used as the cathode in lithium battery systems. Because the electrochemical reaction occurs at the active particles in the porous, composite cathode during charge and discharge, the kinetics of the electrochemical reaction at the active particles in the cathode affects the battery performance. AC impedance has been broadly used to study the kinetics of the electrochemical reaction in the cathode. However, the AC impedance spectra have been analyzed by regarding the porous cathode as a planar electrode by most

  13. Shock-activated electrochemical power supplies

    DOEpatents

    Benedick, W.B.; Graham, R.A.; Morosin, B.

    1987-04-20

    A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolyte rendering the electrolyte electrochemically active. 2 figs.

  14. Shock-activated electrochemical power supplies

    DOEpatents

    Benedick, William B.; Graham, Robert A.; Morosin, Bruno

    1988-01-01

    A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolytes rendering the electrolyte electrochemically active.

  15. Shock-activated electrochemical power supplies

    DOEpatents

    Benedick, W.B.; Graham, R.A.; Morosin, B.

    1988-11-08

    A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolytes rendering the electrolyte electrochemically active. 2 figs.

  16. Electrochemical components employing polysiloxane-derived binders

    DOEpatents

    Delnick, Frank M.

    2013-06-11

    A processed polysiloxane resin binder for use in electrochemical components and the method for fabricating components with the binder. The binder comprises processed polysiloxane resin that is partially oxidized and retains some of its methyl groups following partial oxidation. The binder is suitable for use in electrodes of various types, separators in electrochemical devices, primary lithium batteries, electrolytic capacitors, electrochemical capacitors, fuel cells and sensors.

  17. Parallel Electrochemical Treatment System and Application for Identifying Acid-Stable Oxygen Evolution Electrocatalysts

    DOE PAGES

    Jones, Ryan J. R.; Shinde, Aniketa; Guevarra, Dan; ...

    2015-01-05

    There are many energy technologies require electrochemical stability or preactivation of functional materials. Due to the long experiment duration required for either electrochemical preactivation or evaluation of operational stability, parallel screening is required to enable high throughput experimentation. We found that imposing operational electrochemical conditions to a library of materials in parallel creates several opportunities for experimental artifacts. We discuss the electrochemical engineering principles and operational parameters that mitigate artifacts int he parallel electrochemical treatment system. We also demonstrate the effects of resistive losses within the planar working electrode through a combination of finite element modeling and illustrative experiments. Operationmore » of the parallel-plate, membrane-separated electrochemical treatment system is demonstrated by exposing a composition library of mixed metal oxides to oxygen evolution conditions in 1M sulfuric acid for 2h. This application is particularly important because the electrolysis and photoelectrolysis of water are promising future energy technologies inhibited by the lack of highly active, acid-stable catalysts containing only earth abundant elements.« less

  18. Parallel Electrochemical Treatment System and Application for Identifying Acid-Stable Oxygen Evolution Electrocatalysts

    SciTech Connect

    Jones, Ryan J. R.; Shinde, Aniketa; Guevarra, Dan; Xiang, Chengxiang; Haber, Joel A.; Jin, Jian; Gregoire, John M.

    2015-01-05

    There are many energy technologies require electrochemical stability or preactivation of functional materials. Due to the long experiment duration required for either electrochemical preactivation or evaluation of operational stability, parallel screening is required to enable high throughput experimentation. We found that imposing operational electrochemical conditions to a library of materials in parallel creates several opportunities for experimental artifacts. We discuss the electrochemical engineering principles and operational parameters that mitigate artifacts int he parallel electrochemical treatment system. We also demonstrate the effects of resistive losses within the planar working electrode through a combination of finite element modeling and illustrative experiments. Operation of the parallel-plate, membrane-separated electrochemical treatment system is demonstrated by exposing a composition library of mixed metal oxides to oxygen evolution conditions in 1M sulfuric acid for 2h. This application is particularly important because the electrolysis and photoelectrolysis of water are promising future energy technologies inhibited by the lack of highly active, acid-stable catalysts containing only earth abundant elements.

  19. Electrodeposited cobalt-sulfide catalyst for electrochemical and photoelectrochemical hydrogen generation from water.

    PubMed

    Sun, Yujie; Liu, Chong; Grauer, David C; Yano, Junko; Long, Jeffrey R; Yang, Peidong; Chang, Christopher J

    2013-11-27

    A cobalt-sulfide (Co-S) film prepared via electrochemical deposition on conductive substrates is shown to behave as an efficient and robust catalyst for electrochemical and photoelectrochemical hydrogen generation from neutral pH water. Electrochemical experiments demonstrate that the film exhibits a low catalytic onset overpotential (η) of 43 mV, a Tafel slope of 93 mV/dec, and near 100% Faradaic efficiency in pH 7 phosphate buffer. Catalytic current densities can approach 50 mA/cm(2) and activity is maintained for at least 40 h. The catalyst can also be electrochemically coated on silicon, rendering a water-compatible photoelectrochemical system for hydrogen production under simulated 1 sun illumination. The facile preparation of this Co-S film, along with its low overpotential, high activity, and long-term aqueous stability, offer promising features for potential use in solar energy applications.

  20. Energy conversion and fuel production from electrochemical interfaces

    NASA Astrophysics Data System (ADS)

    Markovic, Nenad

    2012-02-01

    Design and synthesis of energy efficient and stable electrochemical interfaces (materials and double layer components) with tailor properties for accelerating and directing chemical transformations is the key to developing new alternative energy systems -- fuel cells, electrolizers and batteries. In aqueous electrolytes, depending on the nature of the reacting species, the supporting electrolyte, and the metal electrodes, two types of interactions have traditionally been considered: (i) direct -- covalent - bond formation between adsorbates and electrodes, involving chemisorption, electron transfer, and release of the ion hydration shell; and (ii) relatively weak non-covalent metal-ion forces that may affect the concentration of ions in the vicinity of the electrode but do not involve direct metal-adsorbate bonding. The range of physical phenomena associated with these two classes of bonds is unusually broad, and are of paramount importance to understand activity of both metal-electrolyte two phase interfaces and metal-Nafion-electrolyte three phase interfaces. Furthermore, in the past, researcher working in the field of fuel cells (converting hydrogen and oxygen into water) and electrolyzers (splitting water back to H2 and O2) ) seldom focused on understanding the electrochemical compliments of these reactions in battery systems, e.g., the lithium-air system. In this lecture, we address the importance of both covalent and non-covalent interactions in controlling catalytic activity at the two-phase and three-phase interfaces. Although the field is still in its infancy, a great deal has already been learned and trends are beginning to emerge that give new insight into the relationship between the nature of bonding interactions and catalytic activity/stability of electrochemical interfaces. In addition, to bridge the gap between the ``water battery'' (fuel cell <-> electrolyzer) and the Li-air battery systems we demonstrate that this would require fundamentally new

  1. Theoretical and Experimental Study of the Primary Current Distribution in Parallel-Plate Electrochemical Reactors

    ERIC Educational Resources Information Center

    Vazquez Aranda, Armando I.; Henquin, Eduardo R.; Torres, Israel Rodriguez; Bisang, Jose M.

    2012-01-01

    A laboratory experiment is described to determine the primary current distribution in parallel-plate electrochemical reactors. The electrolyte is simulated by conductive paper and the electrodes are segmented to measure the current distribution. Experiments are reported with the electrolyte confined to the interelectrode gap, where the current…

  2. Nanomaterial-Based Electrochemical Biosensors and Bioassays

    SciTech Connect

    Liu, Guodong; Mao, Xun; Gurung, Anant; Baloda, Meenu; Lin, Yuehe; He, Yuqing

    2010-08-31

    This book chapter summarizes the recent advance in nanomaterials for electrochemical biosensors and bioassays. Biofunctionalization of nanomaterials for biosensors fabrication and their biomedical applications are discussed.

  3. Apparatus for combinatorial screening of electrochemical materials

    DOEpatents

    A high throughput combinatorial screening method and apparatus for the evaluation of electrochemical materials using a single voltage source is disclosed wherein temperature changes arising from the application of an electrical load to a cell array are used to evaluate the relative electrochemical efficiency of the materials comprising the array. The apparatus may include an array of electrochemical cells that are connected to each other in parallel or in series, an electronic load for applying a voltage or current to the electrochemical cells , and a device , external to the cells, for monitoring the relative temperature of each cell when the load is applied.

    2009-12-15

    A high throughput combinatorial screening method and apparatus for the evaluation of electrochemical materials using a single voltage source (2) is disclosed wherein temperature changes arising from the application of an electrical load to a cell array (1) are used to evaluate the relative electrochemical efficiency of the materials comprising the array. The apparatus may include an array of electrochemical cells (1) that are connected to each other in parallel or in series, an electronic load (2) for applying a voltage or current to the electrochemical cells (1), and a device (3), external to the cells, for monitoring the relative temperature of each cell when the load is applied.

  4. The simulation model of planar electrochemical transducer

    NASA Astrophysics Data System (ADS)

    Zhevnenko, D. A.; Vergeles, S. S.; Krishtop, T. V.; Tereshonok, D. V.; Gornev, E. S.; Krishtop, V. G.

    2016-12-01

    Planar electrochemical systems are very perspective to build modern motion and pressure sensors. Planar microelectronic technology is successfully used for electrochemical transducer of motion parameters. These systems are characterized by an exceptionally high sensitivity towards mechanic exposure due to high rate of conversion of the mechanic signal to electric current. In this work, we have developed a mathematical model of this planar electrochemical system, which detects the mechanical signals. We simulate the processes of mass and charge transfer in planar electrochemical transducer and calculated its transfer function with different geometrical parameters of the system.

  5. Novel Duplicate Address Detection with Hash Function

    PubMed Central

    Song, GuangJia; Ji, ZhenZhou

    2016-01-01

    Duplicate address detection (DAD) is an important component of the address resolution protocol (ARP) and the neighbor discovery protocol (NDP). DAD determines whether an IP address is in conflict with other nodes. In traditional DAD, the target address to be detected is broadcast through the network, which provides convenience for malicious nodes to attack. A malicious node can send a spoofing reply to prevent the address configuration of a normal node, and thus, a denial-of-service attack is launched. This study proposes a hash method to hide the target address in DAD, which prevents an attack node from launching destination attacks. If the address of a normal node is identical to the detection address, then its hash value should be the same as the “Hash_64” field in the neighboring solicitation message. Consequently, DAD can be successfully completed. This process is called DAD-h. Simulation results indicate that address configuration using DAD-h has a considerably higher success rate when under attack compared with traditional DAD. Comparative analysis shows that DAD-h does not require third-party devices and considerable computing resources; it also provides a lightweight security resolution. PMID:26991901

  6. Enhancing the electrochemical Cr(VI) reduction in aqueous solution.

    PubMed

    Barrera-Díaz, Carlos; Lugo-Lugo, Violeta; Roa-Morales, Gabriela; Natividad, R; Martínez-Delgadillo, S A

    2011-01-30

    In this study we present the cathodic Cr(VI) reduction using electrodissolution of iron anode. In batch experiments we tested four different cathodic materials; the best conditions were found when copper was used. It is observed that when more current is applied into the electrochemical cell faster reduction rates are achieved. Continuous experiments also reveal that Cr(VI) reduction could be done in a very efficient way. To confirm the experimental data, cyclic voltammetry was used and it was found that the cathodic Cr(VI) reduction is taking place.

  7. Molecular-scale measurements of electric fields at electrochemical interfaces.

    SciTech Connect

    Hayden, Carl C.; Farrow, Roger L.

    2011-01-01

    Spatially resolved measurements of electric fields at electrochemical interfaces would be a critical step toward further understanding and modeling the detailed structure of electric double layers. The goal of this project was to perform proof-of-principle experiments to demonstrate the use of field-sensitive dyes for optical measurements of fields in electrochemical systems. A confocal microscope was developed that provides sensitive detection of the lifetime and high resolution spectra of excited fluorescence for dyes tethered to electrically conductive surfaces. Excited state lifetimes for the dyes were measured and found to be relatively unquenched when linked to indium tin oxide, but strongly quenched on gold surfaces. However, our fluorescence detection is sufficiently sensitive to measure spectra of submonolayer dye coatings even when the fluorescence was strongly quenched. Further work to create dye labeled interfaces on flat, uniform and durable substrates is necessary to make electric field measurements at interfaces using field sensitive dyes.

  8. Electrochemical model of the polyaniline based organic memristive device

    SciTech Connect

    Demin, V. A. E-mail: victor.erokhin@fis.unipr.it; Erokhin, V. V. E-mail: victor.erokhin@fis.unipr.it; Kashkarov, P. K.; Kovalchuk, M. V.

    2014-08-14

    The electrochemical organic memristive device with polyaniline active layer is a stand-alone device designed and realized for reproduction of some synapse properties in the innovative electronic circuits, including the neuromorphic networks capable for learning. In this work, a new theoretical model of the polyaniline memristive is presented. The developed model of organic memristive functioning was based on the detailed consideration of possible electrochemical processes occuring in the active zone of this device. Results of the calculation have demonstrated not only the qualitative explanation of the characteristics observed in the experiment but also the quantitative similarities of the resultant current values. It is shown how the memristive could behave at zero potential difference relative to the reference electrode. This improved model can establish a basis for the design and prediction of properties of more complicated circuits and systems (including stochastic ones) based on the organic memristive devices.

  9. Local deposition of anisotropic nanoparticles using scanning electrochemical microscopy (SECM).

    PubMed

    Fedorov, Roman G; Mandler, Daniel

    2013-02-28

    We demonstrate localized electrodeposition of anisotropic metal nanoobjects, namely Au nanorods (GNR), on indium tin oxide (ITO) using scanning electrochemical microscopy (SECM). A gold microelectrode was the source of the gold ions whereby double pulse chronoamperometry was employed to generate initially Au seeds which were further grown under controlled conditions. The distance between the microelectrode and the ITO surface as well as the different experimental parameters (electrodeposition regime, solution composition and temperature) were optimized to produce faceted gold seeds with the required characteristics (size and distribution). Colloidal chemical synthesis was successfully exploited for better understanding the role of the surfactant and different additives in breaking the crystallographic symmetry and anisotropic growth of GNR. Experiments performed in a conventional three-electrode cell revealed the most appropriate electrochemical conditions allowing high yield synthesis of nanorods with well-defined shape as well as nanocubes and bipyramids.

  10. Electrochemical Machining of Metal Plates

    SciTech Connect

    Cooper, J F; Evans, M C

    2005-03-04

    Electrochemical machining (ECM) with concentrated sodium chlorate electrolyte was used to rapidly cut a circular groove (13 cm diameter, 0.2 cm wide) through a 0.15 cm thick sheet of steel--thus opening a 5-inch porthole in as little as 10 minutes. The most favorable operating conditions were: T = 22 C; chlorate concentration 600 g NaClO{sub 3}/liter-solution; electric power of 100 A at 10 V; and flow of 0.5 l/s at a pressure drop of 10 kPa (1.5 psi). The porthole may be removed entirely by electrochemical means, or the electrochemical dissolution may continue until only thin membrane remains that is subsequently cut with a utility knife. An array of thermocouples was used to track temperature in the flowing solution and in the trough being machined; the maximum increase in temperature in the trough was 5 C over that of the flowing electrolyte which increased in temperature by 19 C because of power dissipation. ECM is shown feasible for rapid perforation of plates of ferrous and non-ferrous metals using portable equipment and commercial batteries. The technique can be extended to cut perforations of arbitrary shape through non-planar surfaces using a deformable ring cathode. Analysis of the power requirements for electrolyte flow and ECM indicate a total system weight of less than 45 kg (100 lb) using a commercial NiMH battery. The technique is recommended for reduction to practice and demonstration on full scale as an engineering prototype.

  11. Electrochemical form grinding. Fnal report

    SciTech Connect

    Stiles, R.W.

    1980-06-01

    Electrochemical form grinding cutting tests were performed on 25 17-4 PH stainless steel bars by a copper resin aluminum oxide wheel formed from a diamond form block. Tests investigated methods of dressing a form into a grinding wheel, nozzle design, optimum machine settings, and tolerance capabilities. The electrolyte was distributed evenly onto the wheel by a form-fitting nozzle, and a minimum of two passes, rough and finish, were made because of current density variations throughout the cut. Tolerance held on the form test samples was +- 0.12 mm on the contour, with an average 0.12 mm overcut.

  12. Electrochemical formation of field emitters

    DOEpatents

    Bernhardt, Anthony F.

    1999-01-01

    Electrochemical formation of field emitters, particularly useful in the fabrication of flat panel displays. The fabrication involves field emitting points in a gated field emitter structure. Metal field emitters are formed by electroplating and the shape of the formed emitter is controlled by the potential imposed on the gate as well as on a separate counter electrode. This allows sharp emitters to be formed in a more inexpensive and manufacturable process than vacuum deposition processes used at present. The fabrication process involves etching of the gate metal and the dielectric layer down to the resistor layer, and then electroplating the etched area and forming an electroplated emitter point in the etched area.

  13. Electrochemical Nanoparticle-Based Sensors

    NASA Astrophysics Data System (ADS)

    Wang, Joseph

    Electrochemical devices are extremely useful for delivering analytical information in a fast, simple, and low-cost fashion, and are thus uniquely qualified for meeting the demands of point-of-care diagnostics. In particular, nanoparticles offer elegant ways for interfacing biomolecular recognition events with electronic signal transduction, for dramatically amplifying the resulting electrical response, and for designing novel coding strategies. Nanoparticles, such as colloidal gold or inorganic nanocrystals, offer considerable promise as quantitation tags for biological assays owing to their unique amplification and coding capabilities.

  14. Nanoelectrode array for electrochemical analysis

    DOEpatents

    Yelton, William G.; Siegal, Michael P.

    2009-12-01

    A nanoelectrode array comprises a plurality of nanoelectrodes wherein the geometric dimensions of the electrode controls the electrochemical response, and the current density is independent of time. By combining a massive array of nanoelectrodes in parallel, the current signal can be amplified while still retaining the beneficial geometric advantages of nanoelectrodes. Such nanoelectrode arrays can be used in a sensor system for rapid, non-contaminating field analysis. For example, an array of suitably functionalized nanoelectrodes can be incorporated into a small, integrated sensor system that can identify many species rapidly and simultaneously under field conditions in high-resistivity water, without the need for chemical addition to increase conductivity.

  15. Electrochemical storage cell or battery

    SciTech Connect

    Mennicke, S.; Liebermann, K.; Reiss, K.

    1983-11-08

    Electrochemical storage cell is disclosed, based on alkali metal and chalcogen as reactants with an anode space and a cathode space separated by an alkali ion conducting solid electrolyte wall and bounded by a cell wall of light metal such as aluminum. A strongly adhering metal coating is applied to the area of the light metal wall in contact with one of the reactants. The metal coating chemically reacts to form a sulfide without materially affecting conductivity of the cell wall of light metal and without material increase in the internal resistance of the storage cell.

  16. Electrolyte composition for electrochemical cell

    DOEpatents

    Vissers, Donald R.; Tomczuk, Zygmunt; Anderson, Karl E.; Roche, Michael F.

    1979-01-01

    A high-temperature, secondary electrochemical cell that employs FeS as the positive electrode reactant and lithium or lithium alloy as the negative electrode reactant includes an improved electrolyte composition. The electrolyte comprises about 60-70 mole percent LiCl and 30-40 percent mole percent KCl which includes LiCl in excess of the eutectic composition. The use of this electrolyte suppresses formation of the J phase and thereby improves the utilization of positive electrode active material during cell cycling.

  17. High temperature sealed electrochemical cell

    SciTech Connect

    Valentin Chung, Brice Hoani; Burke, Paul J.; Sadoway, Donald R.

    2015-10-06

    A cell for high temperature electrochemical reactions is provided. The cell includes a container, at least a portion of the container acting as a first electrode. An extension tube has a first end and a second end, the extension tube coupled to the container at the second end forming a conduit from the container to said first end. A second electrode is positioned in the container and extends out of the container via the conduit. A seal is positioned proximate the first end of the extension tube, for sealing the cell.

  18. 49 CFR 1102.1 - How addressed.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false How addressed. 1102.1 Section 1102.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE COMMUNICATIONS § 1102.1 How addressed. All communications...

  19. 49 CFR 1102.1 - How addressed.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 8 2013-10-01 2013-10-01 false How addressed. 1102.1 Section 1102.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE COMMUNICATIONS § 1102.1 How addressed. All communications...

  20. 49 CFR 1102.1 - How addressed.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 8 2014-10-01 2014-10-01 false How addressed. 1102.1 Section 1102.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE COMMUNICATIONS § 1102.1 How addressed. All communications...

  1. 49 CFR 1102.1 - How addressed.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 8 2012-10-01 2012-10-01 false How addressed. 1102.1 Section 1102.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE COMMUNICATIONS § 1102.1 How addressed. All communications...

  2. 49 CFR 1102.1 - How addressed.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false How addressed. 1102.1 Section 1102.1 Transportation Other Regulations Relating to Transportation (Continued) SURFACE TRANSPORTATION BOARD, DEPARTMENT OF TRANSPORTATION RULES OF PRACTICE COMMUNICATIONS § 1102.1 How addressed. All communications...

  3. Public Address Systems. Specifications - Installation - Operation.

    ERIC Educational Resources Information Center

    Palmer, Fred M.

    Provisions for public address in new construction of campus buildings (specifications, installations, and operation of public address systems), are discussed in non-technical terms. Consideration is given to microphones, amplifiers, loudspeakers and the placement and operation of various different combinations. (FS)

  4. 49 CFR 369.6 - Address.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS REPORTS OF MOTOR CARRIERS § 369.6 Address. The following address must be used by motor carriers when submitting a report, requesting an exemption from filing...

  5. 16 CFR 0.2 - Official address.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Official address. 0.2 Section 0.2 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE ORGANIZATION § 0.2... 20580, unless otherwise specifically directed. The Commission's Web site address is www.ftc.gov....

  6. Approaches for Resolving Dynamic IP Addressing.

    ERIC Educational Resources Information Center

    Foo, Schubert; Hui, Siu Cheung; Yip, See Wai; He, Yulan

    1997-01-01

    A problem with dynamic Internet protocol (IP) addressing arises when the Internet connection is through an Internet provider since the IP address is allocated only at connection time. This article examines a number of online and offline methods for resolving the problem. Suggests dynamic domain name system (DNS) and directory service look-up are…

  7. 37 CFR 41.10 - Correspondence addresses.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2011-07-01 2011-07-01 false Correspondence addresses. 41....10 Correspondence addresses. Except as the Board may otherwise direct, (a) Appeals. Correspondence in... all other correspondence in an application or a patent involved in an appeal to the Board for which...

  8. 37 CFR 41.10 - Correspondence addresses.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Correspondence addresses. 41....10 Correspondence addresses. Except as the Board may otherwise direct, (a) Appeals. Correspondence in... all other correspondence in an application or a patent involved in an appeal to the Board for which...

  9. 37 CFR 41.10 - Correspondence addresses.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Correspondence addresses. 41....10 Correspondence addresses. Except as the Board may otherwise direct, (a) Appeals. Correspondence in... all other correspondence in an application or a patent involved in an appeal to the Board for which...

  10. History Forum Addresses Creation/Evolution Controversy.

    ERIC Educational Resources Information Center

    Schweinsberg, John

    1997-01-01

    A series of programs entitled Creationism and Evolution: The History of a Controversy was presented at the University of Alabama in Huntsville. The controversy was addressed from an historical and sociological, rather than a scientific perspective. Speakers addressed the evolution of scientific creationism, ancient texts versus sedimentary rocks…

  11. 34 CFR 674.44 - Address searches.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Address searches. 674.44 Section 674.44 Education..., DEPARTMENT OF EDUCATION FEDERAL PERKINS LOAN PROGRAM Due Diligence § 674.44 Address searches. (a) If mail... litigation; (2) The account is assigned to the United States; or (3) The account is written off under §...

  12. 34 CFR 674.44 - Address searches.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 3 2011-07-01 2011-07-01 false Address searches. 674.44 Section 674.44 Education..., DEPARTMENT OF EDUCATION FEDERAL PERKINS LOAN PROGRAM Due Diligence § 674.44 Address searches. (a) If mail... litigation; (2) The account is assigned to the United States; or (3) The account is written off under §...

  13. Forms of Address in Chilean Spanish

    ERIC Educational Resources Information Center

    Bishop, Kelley; Michnowicz, Jim

    2010-01-01

    The present investigation examines possible social and linguistic factors that influence forms of address used in Chilean Spanish with various interlocutors. A characteristic of the Spanish of Chile is the use of a variety of forms of address for the second person singular, "tu", "vos", and "usted", with corresponding…

  14. Image compression using address-vector quantization

    NASA Astrophysics Data System (ADS)

    Nasrabadi, Nasser M.; Feng, Yushu

    1990-12-01

    A novel vector quantization scheme, the address-vector quantizer (A-VQ), is proposed which exploits the interblock correlation by encoding a group of blocks together using an address-codebook (AC). The AC is a set of address-codevectors (ACVs), each representing a combination of addresses or indices. Each element of the ACV is an address of an entry in the LBG-codebook, representing a vector-quantized block. The AC consists of an active (addressable) region and an inactive (nonaddressable) region. During encoding the ACVs in the AC are reordered adaptively to bring the most probable ACVs into the active region. When encoding an ACV, the active region is checked, and if such an address combination exists, its index is transmitted to the receiver. Otherwise, the address of each block is transmitted individually. The SNR of the images encoded by the A-VQ method is the same as that of a memoryless vector quantizer, but the bit rate is by a factor of approximately two.

  15. Addressing Free Radical Oxidation in Acne Vulgaris

    PubMed Central

    Criscito, Maressa C.; Schlesinger, Todd E.; Verdicchio, Robert; Szoke, Ernest

    2016-01-01

    Objective: Comparatively little attention has been paid to the role of free radical oxidation in acne vulgaris. Here, using the traditional abnormalities cited for acne, the authors address the role of free radical oxidation throughout the pathogenesis by detailing the chemistry that may contribute to clinical changes. To probe the effects of free radical oxidation and test an antioxidant, they conducted a preliminary study of topically applied vitamin E. Methods: Seventeen patients with mild-to-moderate acne vulgaris were evaluated over an eight-week period in two private dermatology practices in this open-label study. All patients enrolled were on the same baseline regimen of salicylic acid and benzoyl peroxide. This regimen was then supplemented with topical vitamin E in sunflower seed oil. Results: At the end of the eight-week period, all patients demonstrated clinical improvement, as indicated by a reduction in the number of lesions and global mean difference. A statistically significant reduction was noted as early as Week 2. Enrolled patients also expressed a positive experience due to good tolerability and easy application. Conclusion: Although the exact pathogenesis of acne vulgaris remains unknown, the presence of excessive reactive oxygen species can be implicated in each of the major abnormalities involved. This presence, along with the positive results of the authors’ preliminary study, demonstrates the need for more exploration on the use of topical antioxidants in limiting free radical oxidation in the acne model. This paper is designed to stimulate academic discussion regarding a new way of thinking about the disease state of acne. PMID:26962389

  16. Addressing the Public About Science and Religion

    NASA Astrophysics Data System (ADS)

    Peshkin, Murray

    2010-03-01

    Attacks on the integrity of science teaching in our public schools have recently become increasingly threatening. Geology and Darwinian evolution are the primary targets and cosmology is at risk. Up to now, the Supreme Court has excluded teachings based on religion from public schools for constitutional, not scientific, reasons. But now the incumbent Supreme Court seem less committed to strict separation of church and state than were their predecessors, and federal courts are beginning to judge the science itself. In this situation, we need to create a climate of public opinion favorable to the protection of good science by explaining the issues both to students and to others. I have been trying to do that by addressing audiences such as church groups, other community groups, and high school and college classes. I do not seek to convert committed anti-evolutionists. I am trying to inform the reasonable majority who do not really know what science is and does, or what a theory is and how we know when it's right, or why we tell them that all knowledge is provisional but still insist that we are teaching the right science. Many have been advised by their religious teachers that there is no conflict between science and their religious beliefs but do not see how that can be. I try to explain how they are disjoint discussions. I also discuss the likely consequences for our country if we degrade the teaching of science in the public schools. My audiences have generally been receptive. Here I will relate some lessons I have learned from my experience with such talks. Without doubt, the most important lesson is that most Americans have religious beliefs that are important to them and are willing to consider what I say only because they know I respect their beliefs. This work was partially supported by the U.S. Dept. of Energy, Office of Nuclear Physics, under contract DE-AC02-06CH11357.

  17. Non-aqueous electrolytes for electrochemical cells

    DOEpatents

    Zhang, Zhengcheng; Dong, Jian; Amine, Khalil

    2016-06-14

    An electrolyte electrochemical device includes an anodic material and an electrolyte, the electrolyte including an organosilicon solvent, a salt, and a hybrid additiving having a first and a second compound, the hybrid additive configured to form a solid electrolyte interphase film on the anodic material upon application of a potential to the electrochemical device.

  18. Porous nickel oxide films for electrochemical capacitors

    SciTech Connect

    Liu, K.C.; Anderson, M.A.

    1995-12-31

    NiO/Ni composite thin films consisting of nano-sized particles have been found to perform as good electrodes in electrochemical capacitor applications. These films can provide a specific capacitance of 25--40 F/g. The low cost of raw materials and easy manufacturing process of this system should allow one to produce low-cost electrochemical capacitors.

  19. Method for making an electrochemical cell

    DOEpatents

    Tuller, Harry L.; Kramer, Steve A.; Spears, Marlene A.; Pal, Uday B.

    1996-01-01

    An electrochemical device including a solid electrolyte and solid electrode composed of materials having different chemical compositions and characterized by different electrical properties but having the same crystalline phase is provided. A method for fabricating an electrochemical device having a solid electrode and solid electrolyte characterized by the same crystalline phase is provided.

  20. Solid oxide electrochemical reactor science.

    SciTech Connect

    Sullivan, Neal P.; Stechel, Ellen Beth; Moyer, Connor J.; Ambrosini, Andrea; Key, Robert J.

    2010-09-01

    Solid-oxide electrochemical cells are an exciting new technology. Development of solid-oxide cells (SOCs) has advanced considerable in recent years and continues to progress rapidly. This thesis studies several aspects of SOCs and contributes useful information to their continued development. This LDRD involved a collaboration between Sandia and the Colorado School of Mines (CSM) ins solid-oxide electrochemical reactors targeted at solid oxide electrolyzer cells (SOEC), which are the reverse of solid-oxide fuel cells (SOFC). SOECs complement Sandia's efforts in thermochemical production of alternative fuels. An SOEC technology would co-electrolyze carbon dioxide (CO{sub 2}) with steam at temperatures around 800 C to form synthesis gas (H{sub 2} and CO), which forms the building blocks for a petrochemical substitutes that can be used to power vehicles or in distributed energy platforms. The effort described here concentrates on research concerning catalytic chemistry, charge-transfer chemistry, and optimal cell-architecture. technical scope included computational modeling, materials development, and experimental evaluation. The project engaged the Colorado Fuel Cell Center at CSM through the support of a graduate student (Connor Moyer) at CSM and his advisors (Profs. Robert Kee and Neal Sullivan) in collaboration with Sandia.

  1. Electrochemical application of DNA biosensors

    NASA Astrophysics Data System (ADS)

    Mascini, M.; Lucarelli, F.; Palchetti, I.; Marrazza, G.

    2001-09-01

    Disposable electrochemical DNA-based biosensors are reviewed; they have been used for the determination of low- molecular weight compounds with affinity for nucleic acids and for the detection of hybridization reaction. The first application is related to the molecular interaction between surface-linked DNA and pollutants or drugs, in order to develop a simple device for rapid screening of toxic compounds. The determination of such compounds was measured by their effect simple device for rapid screening of toxic compounds. The determination of such compounds was measured by their effect on the oxidation signal of the guanine peak of calf thymus DNA immobilized on the electrode surface and investigated by chronopotentiometric or voltammetric analysis. Applicability to river and wastewater sample is demonstrated. Moreover, disposable electrochemical sensors for the detection of a specific sequence of DNA were realized by immobilizing synthetic single-stranded oligonucleotides onto a graphite screen-printed electrode. The probes because hybridized with different concentrations of complementary sequences present in the sample. The hybrids formed on the electrode surface were evaluated by chronopotentiometric analysis using daunomycin as the indicator of the hybridization reaction. The hybridization was also performed using real samples. Application to apolipoprotein E is described, in this case samples have to be amplified by PCR and then analyzed by the DNA biosensor. The extension of such procedures to samples of environmental interest or to contamination of food is discussed.

  2. Buffered Electrochemical Polishing of Niobium

    SciTech Connect

    Gianluigi Ciovati; Tian, Hui; Corcoran, Sean

    2011-03-01

    The standard preparation of superconducting radio-frequency (SRF) cavities made of pure niobium include the removal of a 'damaged' surface layer, by buffered chemical polishing (BCP) or electropolishing (EP), after the cavities are formed. The performance of the cavities is characterized by a sharp degradation of the quality factor when the surface magnetic field exceeds about 90 mT, a phenomenon referred to as 'Q-drop.' In cavities made of polycrystalline fine grain (ASTM 5) niobium, the Q-drop can be significantly reduced by a low-temperature (? 120 °C) 'in-situ' baking of the cavity if the chemical treatment was EP rather than BCP. As part of the effort to understand this phenomenon, we investigated the effect of introducing a polarization potential during buffered chemical polishing, creating a process which is between the standard BCP and EP. While preliminary results on the application of this process to Nb cavities have been previously reported, in this contribution we focus on the characterization of this novel electrochemical process by measuring polarization curves, etching rates, surface finish, electrochemical impedance and the effects of temperature and electrolyte composition. In particular, it is shown that the anodic potential of Nb during BCP reduces the etching rate and improves the surface finish.

  3. Electrochemical treatment of liquid wastes

    SciTech Connect

    Hobbs, D.T.

    1997-10-01

    Under this task, electrochemical treatment processes are being evaluated and developed for the destruction of organic compounds and nitrates/nitrites and the removal of other hazardous species from liquid wastes stored throughout the DOE complex. This technology targets the (1) destruction of nitrates, nitrites and organic compounds; (2) removal of radionuclides; and (3) removal of RCRA metals. The development program consists of five major tasks: (1) evaluation of electrochemical reactors for the destruction and removal of hazardous waste components, (2) development and validation of engineering process models, (3) radioactive laboratory-scale tests, (4) demonstration of the technology in an engineering-scale reactor, and (5) analysis and evaluation of test data. The development program team is comprised of individuals from national laboratories, academic institutions, and private industry. Possible benefits of this technology include: (1) improved radionuclide separation as a result of the removal of organic complexants, (2) reduction in the concentrations of hazardous and radioactive species in the waste (e.g., removal of nitrate, mercury, chromium, cadmium, {sup 99}Tc, and {sup 106}Ru), (3) reduction in the size of the off-gas handling equipment for the vitrification of low-level waste (LLW) by reducing the source of NO{sub x} emissions, (4) recovery of chemicals of value (e.g. sodium hydroxide), and (5) reduction in the volume of waste requiring disposal.

  4. Electrochemically assisted pyrolysis of hardwoods

    SciTech Connect

    Koch, V.R.

    1986-08-01

    This project explored the low-temperature, electrochemically assisted pyrolysis of lignocellulosic material to low-molecular-weight organic chemicals. Through the agency of low temperature AlCl{sub 3}-based molten salts, aspen hardwood flour was reacted in AlCl{sub 3}:NaCl, AlCl{sub 3}:NaCl:KCl, and AlCl{sub 3}:BPC (n-butylpyridinium chloride) media at temperatures from 30-220 C. A wide variety of water soluble products were formed comprising CO, CO{sub 2}, keto-alcohols and low molecular weight phenolic compounds as determined by GC and FTIR spectroscopy. The compounds represented about 32% by weight of the aspen wood flour. Owing to the narrow (2 volt) electrochemical window versus an Al reference electrode, neither the wood flour nor the reaction products manifested any electro-activity. Authentic samples of cellulose, hemicellulose, and Klason lignin were also subjected to low temperature pyrolysis. Only the hemicellulose reacted to give CO{sub 2} and keto-alcohols.

  5. Topics in electrochemical degradation of photovoltaic modules

    NASA Technical Reports Server (NTRS)

    Mon, G. R.

    1984-01-01

    Electrochemical degradation of photovoltaic modules was examined. It is found that the extent of electrochemical damage is dependent on the integrated leakage current. The PV electrochemical degradation mechanisms in the two polarities are different: (1) degradation rates in the two polarities are of the same order of magnitude; (2) center tapped grounded arrays are a preferred system configuration to minimize electrochemical degradation. The use of thicker pottant layers and polymer substrate films to reduce equilibrium leakage current values is suggested. A metallized substrate layer, if used, should be isolated from the pottant and the frame by polyester layers, and EVA modules appear to be consistent with 30 year life allocation levels for electrochemical damage. Temperature acceleration factors are well behaved and moderately well understood; humidity acceleration factors vary radically with module construction and materials and require additional research.

  6. Electrochemical post-functionalization of conducting polymers.

    PubMed

    Inagi, Shinsuke; Fuchigami, Toshio

    2014-05-01

    This article summarizes recent progress in the post-functionalization of conjugated polymers by electrochemical methods. These electrochemical polymer reactions typically proceed via electrochemical doping of a conjugated polymer film, followed by chemical transformation. Examples include the quantitative oxidative fluorination of polyfluorenes and oxidative halogenation of polythiophenes, as well as the reductive hydrogenation of polyfluorenones. The degree of functionalization, otherwise known as the reaction ratio, can be controlled by varying the charge passed through the polymer, allowing the optoelectronic properties of the conjugated polymers to be tailored. Wireless bipolar electrodes with an in-plane potential distribution are also useful with regard to the electrochemical doping and reaction of conjugated polymers and allow the synthesis of films exhibiting composition gradients. Such bipolar electrochemistry can induce multiple reaction sites during electrochemical polymer reactions.

  7. Bussing Structure In An Electrochemical Cell

    DOEpatents

    Romero, Antonio L.

    2001-06-12

    A bussing structure for bussing current within an electrochemical cell. The bussing structure includes a first plate and a second plate, each having a central aperture therein. Current collection tabs, extending from an electrode stack in the electrochemical cell, extend through the central aperture in the first plate, and are then sandwiched between the first plate and second plate. The second plate is then connected to a terminal on the outside of the case of the electrochemical cell. Each of the first and second plates includes a second aperture which is positioned beneath a safety vent in the case of the electrochemical cell to promote turbulent flow of gasses through the vent upon its opening. The second plate also includes protrusions for spacing the bussing structure from the case, as well as plateaus for connecting the bussing structure to the terminal on the case of the electrochemical cell.

  8. Electrochemical hydrogenation of thiophene on SPE electrodes

    NASA Astrophysics Data System (ADS)

    Huang, Haiyan; Yuan, Penghui; Yu, Ying; Chung, Keng H.

    2017-01-01

    Electrochemical reduction desulfurization is a promising technology for petroleum refining which is environmental friendly, low cost and able to achieve a high degree of automation. Electrochemical hydrogenation of thiophene was performed in a three-electrode system which SPE electrode was the working electrode. The electrochemical desulfurization was studied by cyclic voltammetry and bulk electrolysis with coulometry (BEC) techniques. The results of cyclic voltammetry showed that the electrochemical hydrogenation reduction reaction occurred at -0.4V. The BEC results showed that the currents generated from thiophene hydrogenation reactions increased with temperature. According to Arrhenius equation, activation energy of thiophene electrolysis was calculated and lower activation energy value indicated it was diffusion controlled reaction. From the products of electrolytic reactions, the mechanisms of electrochemical hydrogenation of thiophene were proposed, consisting of two pathways: openingring followed by hydrogenation, and hydrogenation followed by ring opening.

  9. Preparation of activated carbon from wet sludge by electrochemical-NaClO activation.

    PubMed

    Miao, Chen; Ye, Caihong; Zhu, Tianxing; Lou, Ziyang; Yuan, Haiping; Zhu, Nanwen

    2014-01-01

    Activated carbon (AC) from sludge is one potential solution for sewage sludge disposal, while the drying sludge is cost and time consuming for preparation. AC preparation from the wet sludge with electrochemical-NaClO activation was studied in this work. Three pretreatment processes, i.e. chemical activation, electrolysis and electrochemical-reagent reaction, were introduced to improve the sludge-derived AC properties, and the optimum dosage of reagent was tested from the 0.1:1 to 1:1 (mass rate, reagent:dried sludge). It was shown that the electrochemical-NaClO preparation is the best method under the test conditions, in which AC has the maximum Brunauer, Emmett and Teller area of 436 m²/g at a mass ratio of 0.7. Extracellular polymeric substances in sludge can be disintegrated by electrochemical-NaClO pretreatment, with a disintegration degree of more than 45%. The percentage of carbon decreased from 34.16 to 8.81 after treated by electrochemical-NaClO activation. Fourier transform infrared spectra showed that a strong C-Cl stretching was formed in electrochemical-NaClO prepared AC. The maximum adsorption capacity of AC reaches 109 mg/g on MB adsorption experiment at pH 10 and can be repeated for three times with high removal efficiency after regeneration.

  10. Microfluidic platform for studying the electrochemical reduction of carbon dioxide

    NASA Astrophysics Data System (ADS)

    Whipple, Devin Talmage

    Diminishing supplies of conventional energy sources and growing concern over greenhouse gas emissions present significant challenges to supplying the world's rapidly increasing demand for energy. The electrochemical reduction of carbon dioxide has the potential to address many of these issues by providing a means of storing electricity in chemical form. Storing electrical energy as chemicals is beneficial for leveling the output of clean, but intermittent renewable energy sources such as wind and solar. Electrical energy stored as chemicals can also be used as carbon neutral fuels for portable applications allowing petroleum derived fuels in the transportation sector to be replaced by more environmentally friendly energy sources. However, to be a viable technology, the electrochemical reduction of carbon dioxide needs to have both high current densities and energetic efficiencies (Chapter 1). Although many researchers have studied the electrochemical reduction of CO2 including parameters such as catalysts, electrolytes and temperature, further investigation is needed to improve the understanding of this process and optimize the performance (Chapter 2). This dissertation reports the development and validation of a microfluidic reactor for the electrochemical reduction of CO2 (Chapter 3). The design uses a flowing liquid electrolyte instead of the typical polymer electrolyte membrane. In addition to other benefits, this flowing electrolyte gives the reactor great flexibility, allowing independent analysis of each electrode and the testing of a wide variety of conditions. In this work, the microfluidic reactor has been used in the following areas: • Comparison of different metal catalysts for the reduction of CO2 to formic acid and carbon monoxide (Chapter 4). • Investigation of the effects of the electrolyte pH on the reduction of CO2 to formic acid and carbon monoxide (Chapter 5). • Study of amine based electrolytes for lowering the overpotentials for CO2

  11. Surface design and engineering of hierarchical hybrid nanostructures for asymmetric supercapacitors with improved electrochemical performance.

    PubMed

    Achilleos, Demetra S; Hatton, T Alan

    2015-06-01

    With the current rising world demand for energy sufficiency, there is an increased necessity for the development of efficient energy storage devices. To address these needs, the scientific community has focused on the improvement of the electrochemical properties of the most well known energy storage devices; the Li-ion batteries and electrochemical capacitors, also called supercapacitors. Despite the fact that supercapacitors exhibit high power densities, good reversibility and long cycle life, they still exhibit lower energy densities than batteries, which limit their practical application. Various strategies have been employed to circumvent this problem, specifically targetting an increase in the specific capacitance and the broadening of the potential window of operation of these systems. In recent years, sophisticated surface design and engineering of hierarchical hybrid nanostructures has facilitated significant improvements in the specific and volumetric storage capabilities of supercapacitors. These nanostructured electrodes exhibit higher surface areas for ion adsorption and reduced ion diffusion lengths for the electrolyte ions. Significant advances have also been achieved in broadening the electrochemical window of operation of these systems, as realized via the development of asymmetric two-electrode cells consisting of nanocomposite positive and negative electrodes with complementary electrochemical windows, which operate in environmentally benign aqueous media. We provide an overview of the diverse approaches, in terms of chemistry and nanoscale architecture, employed recently for the development of asymmetric supercapacitors of improved electrochemical performance.

  12. Sequence-specific electrochemical detection of asymmetric PCR amplicons of traditional Chinese medicinal plant DNA.

    PubMed

    Lee, Thomas M H; Hsing, I-Ming

    2002-10-01

    In this study, an electrochemistry-based approach to detect nucleic acid amplification products of Chinese herbal genes is reported. Using asymmetric polymerase chain reaction and electrochemical techniques, single-stranded target amplicons are produced from trace amounts of DNA sample and sequence-specific electrochemical detection based on the direct hybridization of the crude amplicon mix and immobilized DNA probe can be achieved. Electrochemically active intercalator Hoechst 33258 is bound to the double-stranded duplex formed by the target amplicon hybridized with the 5'-thiol-derivated DNA probe (16-mer) on the gold electrode surface. The electrochemical current signal of the hybridization event is measured by linear sweep voltammetry, the response of which can be used to differentiate the sequence complementarities of the target amplicons. To improve the reproducibility and sensitivity of the current signal, issues such as electrode surface cleaning, probe immobilization, and target hybridization are addressed. Factors affecting hybridization efficiency including the length and binding region of the target amplicon are discussed. Using our approach, differentiation of Chinese herbal species Fritillaria (F. thunbergii and F. cirrhosa) based on the 16-mer unique sequences in the spacer region of the 5S-rRNA is demonstrated. The ability to detect PCR products using a nonoptical electrochemical detection technique is an important step toward the realization of portable biomicrodevices for on-spot bacterial and viral detections.

  13. Electrochemical Sensing for a Rapidly Evolving World

    NASA Astrophysics Data System (ADS)

    Mullen, Max Robertson

    This dissertation focuses on three projects involving the development of harsh environment gas sensors. The first project discusses the development of a multipurpose oxygen sensor electrode for use in sealing with the common electrolyte yttria stabilized zirconia. The purpose of the sealing function is to produce an internal reference environment maintained by a metal/metal oxide mixture, a criteria for miniaturization of potentiometric oxygen sensing technology. This sensor measures a potential between the internal reference and a sensing environment. The second project discusses the miniaturization of an oxygen sensor and the fabrication of a more generalized electrochemical sensing platform. The third project discusses the discovery of a new mechanism in the electrochemical sensing of ammonia through molecular recognition and the utilization of a sensor taking advantage of the new mechanism. An initial study involving the development of a microwave synthesized La0.8Sr0.2Al0.9Mn0.1O3 sensor electrode material illustrates the ability of the material developed to meet ionic and electronic conducting requirements for effective and Nernstian oxygen sensing. In addition the material deforms plastically under hot isostatic pressing conditions in a similar temperature and pressure regime with yttria stabilized zirconia to produce a seal and survive temperatures up to 1350 °C. In the second project we show novel methods to seal an oxygen environment inside a device cavity to produce an electrochemical sensor body using room temperature plasma-activated bonding and low temperature and pressure assisted plasma-activated bonding with silicon bodies, both in a clean room environment. The evolution from isostatic hot pressing methods towards room temperature complementary metal oxide semiconductor (CMOS) compatible technologies using single crystal silicon substrates in the clean room allows the sealing of devices on a much larger scale. Through this evolution in bonding

  14. Carbon nanotubes-A resin for electrochemically modulated liquid chromatography.

    PubMed

    Brammen, Markus; Fraga-García, Paula; Berensmeier, Sonja

    2017-03-01

    Electrochemically modulated liquid chromatography is a special form of ion exchange chromatography in which the separation process is controlled by applying an electric potential to the stationary phase. This form of chromatography has so far only been applied in research studies. The present study shows that multiwalled carbon nanotubes are an effective resin material for an electrochemically modulated chromatography process. The experiments are carried out in a newly designed column that enables the packing of nanomaterials. We investigate the influence of the applied potential on the retention and elution of maleic acid, determine the dynamic binding capacity, and calculate the utilization degree of the electrical charge in the adsorption process. Moreover, the stability of the resin and the membrane over more than 200 working hours are presented. In addition to the stability, their sturdiness and inexpensive price are important qualities that make multiwalled carbon nanotubes interesting for application as the stationary phase in an electrochemically driven process. The investigated chromatography technique represents a promising separation process for future applications as a preparative step in biotechnology as well as other life science fields.

  15. Opto-electrochemical spectroscopy of metals in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Habib, K.

    2016-03-01

    In the present investigation, holographic interferometry was utilized for the first time to determine the rate change of the electrical resistance of aluminium samples during the initial stage of anodisation processes in aqueous solution. In fact, because the resistance values in this investigation were obtained by holographic interferometry, electromagnetic method rather than electronic method, the abrupt rate change of the resistance was called electrical resistance-emission spectroscopy. The anodisation process of the aluminium samples was carried out by electrochemical impedance spectroscopy (EIS) in different sulphuric acid concentrations (1.0%-2.5% H2SO4) at room temperature. In the meantime, the real time holographic interferometry was used to determine the difference between the electrical resistance of two subsequent values, dR, as a function of the elapsed time of the EIS experiment for the aluminium samples in 1.0%, 1.5%, 2.0%, and 2.5% H2SO4 solutions. The electrical resistance-emission spectra of the present investigation represent a detailed picture of not only the rate change of the electrical resistance throughout the anodisation processes but also the spectra represent the rate change of the growth of the oxide films on the aluminium samples in different solutions. As a result, a new spectrometer was developed based on the combination of the holographic interferometry and electrochemical impedance spectroscopy for studying in situ the electrochemical behavior of metals in aqueous solutions.

  16. Treatment of Radioactive Organic Wastes by an Electrochemical Oxidation

    SciTech Connect

    Kim, K.H.; Ryue, Y.G.; Kwak, K.K.; Hong, K.P.; Kim, D.H.

    2007-07-01

    A waste treatment system by using an electrochemical oxidation (MEO, Mediated Electrochemical Oxidation) was installed at KAERI (Korea Atomic Energy Research Institute) for the treatment of radioactive organic wastes, especially EDTA (Ethylene Diamine Tetraacetic Acid) generated during the decontamination activity of nuclear installations. A cerium and silver mediated electrochemical oxidation technique method has been developed as an alternative for an incineration process. An experiment to evaluate the applicability of the above two processes and to establish the conditions to operate the pilot-scale system has been carried out by changing the concentration of the catalyst and EDTA, the operational current density, the operating temperature, and the electrolyte concentration. As for the results, silver mediated oxidation was more effective in destructing the EDTA wastes than the cerium mediated oxidation process. For a constant volume of the EDTA wastes, the treatment time for the cerium-mediated oxidation was 9 hours and its conversion ratio of EDTA to water and CO{sub 2} was 90.2 % at 80 deg. C, 10 A, but the treatment time for the silver-mediated oxidation was 3 hours and its conversion ratio was 89.2 % at 30 deg. C, 10 A. (authors)

  17. Addressing Your Child's Weight at the Doctor

    MedlinePlus

    ... a Healthy Heart Healthy Kids Our Kids Programs Childhood Obesity What is childhood obesity? Overweight in Children BMI in Children Is Childhood Obesity an Issue in Your Home? Addressing your Child's ...

  18. 7 CFR 504.5 - Address.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... USER FEES § 504.5 Address. Deposits of and requests for microbial patent cultures should be directed to the Curator, ARS Patent Culture Collection, Northern Regional Research Center, USDA-ARS, 1815...

  19. 7 CFR 504.5 - Address.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... USER FEES § 504.5 Address. Deposits of and requests for microbial patent cultures should be directed to the Curator, ARS Patent Culture Collection, Northern Regional Research Center, USDA-ARS, 1815...

  20. 7 CFR 504.5 - Address.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... USER FEES § 504.5 Address. Deposits of and requests for microbial patent cultures should be directed to the Curator, ARS Patent Culture Collection, Northern Regional Research Center, USDA-ARS, 1815...

  1. 7 CFR 504.5 - Address.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... USER FEES § 504.5 Address. Deposits of and requests for microbial patent cultures should be directed to the Curator, ARS Patent Culture Collection, Northern Regional Research Center, USDA-ARS, 1815...

  2. 7 CFR 504.5 - Address.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... USER FEES § 504.5 Address. Deposits of and requests for microbial patent cultures should be directed to the Curator, ARS Patent Culture Collection, Northern Regional Research Center, USDA-ARS, 1815...

  3. 76 FR 27020 - Representative and Address Provisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE United States Patent and Trademark Office Representative and Address Provisions ACTION: Proposed collection; comment request. SUMMARY: The United States Patent and Trademark Office (USPTO), as part of...

  4. Optical Addressing And Clocking Of RAM's

    NASA Technical Reports Server (NTRS)

    Johnston, Alan R.; Nixon, Robert H.; Bergman, Larry A.; Esener, Sadik

    1989-01-01

    Proposed random-access-memory (RAM) addressing system, in which memory linked optically to read/write logic circuits, greatly increases computer operating speed. System - comprises addressing circuits including numerous lasers as signal sources, numerous optical gates including optical detectors associated with memory cells, and holographic element to direct light signals to desired memory-cell locations - applied to high-capacity digital systems, supercomputers, and complex microcircuits.

  5. Contextual analysis of machine-printed addresses

    NASA Astrophysics Data System (ADS)

    Cullen, Peter B.; Ho, Tin K.; Hull, Jonathan J.; Prussak, Michal; Srihari, Sargur N.

    1992-08-01

    The assignment of a nine digit ZIP Code (ZIP + 4 Code) to the digital image of a machine printed address block is a problem of central importance in automated mail sorting. This problem is especially difficult since most addresses do not contain ZIP + 4 Codes and often the information that must be read to match an address to one of the 28 million entries in the ZIP + 4 file is either erroneous, incomplete, or missing altogether. This paper discusses a system for interpreting a machine printed address and assigning a ZIP + 4 Code that uses a constraint satisfaction approach. Words in an address block are first segmented and parsed to assign probable semantic categories. Word images are then recognized by a combination of digit, character, and word recognition algorithms. The control structure uses a constraint satisfaction problem solving approach to match the recognition results to an entry in the ZIP + 4 file. It is shown how this technique can both determine correct responses as well as compensate for incomplete or erroneous information. Experimental results demonstrate the success of this system. In a recent test on over 1000 machine printed address blocks, the ZIP + 4 encode rate was over 73 percent. This compares to the success rate of current postal OCRs which is about 45 percent. Additionally, the word recognition algorithm recognizes over 92 percent of the input images (over 98 percent in the top 10 choices.

  6. A generic platform for the addressable functionalisation of electrode surfaces through self-induced "electroclick".

    PubMed

    Orain, Christophe; Le Poul, Nicolas; Gomila, Antoine; Kerbaol, Jean-Michel; Cosquer, Nathalie; Reinaud, Olivia; Conan, Françoise; Le Mest, Yves

    2012-01-09

    A novel and general strategy for the immobilisation of functional objects onto electrodes is described. The concept is based on the addition of two pendant ethynyl groups onto a bis(pyridyl)amine derivative, which acts as a molecular platform. This platform is pre-functionalised with an N(3)-tagged object of interest by Huisgen cycloaddition to one of the ethynyl groups in biphasic conditions. Hence, when complexed by Cu(II) , this molecular-object holder can be immobilised, by a "self-induced electroclick", through the second ethynyl group onto N(3)-alkanethiol self-assembled monolayers on a gold electrode. Two different functional groups, a redox innocent ((CH(2))(3)-Ph) and an electrochemical probe (ferrocene), were immobilised by following this strategy. The in situ electrochemical grafting showed, for both systems, that the kinetics of immobilisation is fast. The voltammetric characterisation of the surface-tagged functionalised copper complexes indicated that a good surface coverage was achieved and that a moderately fast electron-transfer reaction occurs. Remarkably, in the case of the redox-active ferrocenyl-immobilised system, the electrochemical response highlighted the involvement of the copper ion of the platform in the kinetics of the electron transfer to the ferrocene moiety. This platform is a promising candidate for applications in surface addressing in areas as diverse as biology and materials.

  7. Electrochemically driven formation of a molecular capsule around the ferrocenium ion.

    PubMed

    Philip, Ivy E; Kaifer, Angel E

    2002-10-30

    Electrochemical experiments were used to show that the oxidation of ferrocene triggers the self-assembly of six molecules of the resocin[4]arene 2 to form a molecular capsule around the oxidized, ferrocenium (+1) form. The nature of the supporting electrolyte anion is crucial for this process of electrochemically driven self-assembly. 1H NMR spectroscopic data obtained with cobaltocenium, a diamagnetic analogue of the paramagnetic ferrocenium ion, verify its encapsulation by six molecules of 2. The encapsulation of cobaltocenium was also observed in voltammetric experiments. Encapsulation of ferrocenium (or cobaltocenium) inside the large 26 capsule led to a dramatic slowing of its usually fast, one-electron electrochemical reduction to ferrocene (or cobaltocene).

  8. Addressing contrasting cognitive models in scientific collaboration

    NASA Astrophysics Data System (ADS)

    Diviacco, P.

    2012-04-01

    If the social aspects of scientific communities and their internal dynamics is starting to be recognized and acknowledged in the everyday lives of scientists, it is rather difficult for them to find tools that could support their activities consistently with this perspective. Issues span from gathering researchers to mutual awareness, from information sharing to building meaning, with the last one being particularly critical in research fields as the geo-sciences, that deal with the reconstruction of unique, often non-reproducible, and contingent processes. Reasoning here is, in fact, mainly abductive, allowing multiple and concurrent explanations for the same phenomenon to coexist. Scientists bias one hypothesis over another not only on strictly logical but also on sociological motivations. Following a vision, scientists tend to evolve and isolate themselves from other scientists creating communities characterized by different cognitive models, so that after some time these become incompatible and scientists stop understanding each other. We address these problems as a communication issue so that the classic distinction into three levels (syntactic, semantic and pragmatic) can be used. At the syntactic level, we highlight non-technical obstacles that condition interoperability and data availability and transparency. At the semantic level, possible incompatibilities of cognitive models are particularly evident, so that using ontologies, cross-domain reconciliation should be applied. This is a very difficult task to perform since the projection of knowledge by scientists, in the designated community, is political and thus can create a lot of tension. The strategy we propose to overcome these issues pertains to pragmatics, in the sense that it is intended to acknowledge the cultural and personal factors each partner brings into the collaboration and is based on the idea that meaning should remain a flexible and contingent representation of possibly divergent views

  9. The origin of electrochemical nomenclature.

    PubMed

    Giddens, W R

    2001-09-01

    This article is about the origin and development of certain words that are important in the vocabulary of all physicians and scientists. The words that make up the electrochemical nomenclature were created in 1833 by Michael Faraday and several of his friends. Terms such as electrolyte, ion, and electrode were invented in a fashion that ignored theory but fitted the experimental facts of the laboratory. This nomenclature, derived from Greek, was so accurate and functional that is has been completely incorporated into modern chemistry, a fact that seems remarkable since the structure of the atom was completely unknown at the time. To fully develop the etymology of these words, the life of Faraday is summarized and the deliberations of the men involved are reviewed.

  10. Composite Electrodes for Electrochemical Supercapacitors

    NASA Astrophysics Data System (ADS)

    Li, Jun; Yang, Quan Min; Zhitomirsky, Igor

    2010-03-01

    Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 4-6 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNT) into porous Ni plaque current collectors. Obtained composite electrodes, containing 85% of manganese dioxide and 15 mass% of MWCNT, as a conductive additive, with total mass loading of 7-15 mg cm-2, showed a capacitive behavior in 0.5-M Na2SO4 solutions. The decrease in stirring time during precipitation of the nanofibers resulted in reduced agglomeration and higher specific capacitance (SC). The highest SC of 185 F g-1 was obtained at a scan rate of 2 mV s-1 for mass loading of 7 mg cm-2. The SC decreased with increasing scan rate and increasing electrode mass.

  11. Electrochemical formation of field emitters

    DOEpatents

    Bernhardt, A.F.

    1999-03-16

    Electrochemical formation of field emitters, particularly useful in the fabrication of flat panel displays is disclosed. The fabrication involves field emitting points in a gated field emitter structure. Metal field emitters are formed by electroplating and the shape of the formed emitter is controlled by the potential imposed on the gate as well as on a separate counter electrode. This allows sharp emitters to be formed in a more inexpensive and manufacturable process than vacuum deposition processes used at present. The fabrication process involves etching of the gate metal and the dielectric layer down to the resistor layer, and then electroplating the etched area and forming an electroplated emitter point in the etched area. 12 figs.

  12. Scanning Electrochemical Microscopy in Neuroscience

    NASA Astrophysics Data System (ADS)

    Schulte, Albert; Nebel, Michaela; Schuhmann, Wolfgang

    2010-07-01

    This article reviews recent work involving the application of scanning electrochemical microscopy (SECM) to the study of individual cultured living cells, with an emphasis on topographical and functional imaging of neuronal and secretory cells of the nervous and endocrine system. The basic principles of biological SECM and associated negative amperometric-feedback and generator/collector-mode SECM imaging are discussed, and successful use of the methodology for screening soft and fragile membranous objects is outlined. The drawbacks of the constant-height mode of probe movement and the benefits of the constant-distance mode of SECM operation are described. Finally, representative examples of constant-height and constant-distance mode SECM on a variety of live cells are highlighted to demonstrate the current status of single-cell SECM in general and of SECM in neuroscience in particular.

  13. Cathode for an electrochemical cell

    DOEpatents

    Bates, John B.; Dudney, Nancy J.; Gruzalski, Greg R.; Luck, Christopher F.

    2001-01-01

    Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode. Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between -15.degree. C. and 150.degree. C.

  14. Electrolyte for an electrochemical cell

    DOEpatents

    Bates, J.B.; Dudney, N.J.

    1997-01-28

    Described is a thin-film battery, especially a thin-film microbattery, and a method for making the same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte amorphous lithium phosphorus oxynitride which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between {minus}15 C and 150 C. 9 figs.

  15. Electrolyte for an electrochemical cell

    DOEpatents

    Bates, John B.; Dudney, Nancy J.

    1997-01-01

    Described is a thin-film battery, especially a thin-film microbattery, and a method for making same having application as a backup or primary integrated power source for electronic devices. The battery includes a novel electrolyte amorphous lithium phosphorus oxynitride which is electrochemically stable and does not react with the lithium anode and a novel vanadium oxide cathode Configured as a microbattery, the battery can be fabricated directly onto a semiconductor chip, onto the semiconductor die or onto any portion of the chip carrier. The battery can be fabricated to any specified size or shape to meet the requirements of a particular application. The battery is fabricated of solid state materials and is capable of operation between -15.degree. C. and 150.degree. C.

  16. Electrochemical studies of corrosion inhibitors

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1990-01-01

    The effect of single salts, as well as multicomponent mixtures, on corrosion inhibition was studied for type 1010 steel; for 5052, 1100, and 2219-T87 aluminum alloys; and for copper. Molybdate-containing inhibitors exhibit an immediate, positive effect for steel corrosion, but an incubation period may be required for aluminum before the effect of a given inhibitor can be determined. The absence of oxygen was found to provide a positive effect (smaller corrosion rate) for steel and copper, but a negative effect for aluminum. This is attributed to the two possible mechanisms by which aluminum can oxidize. Corrosion inhibition is generally similar for oxygen-rich and oxygen-free environments. The results show that the electrochemical method is an effective means of screening inhibitors for the corrosion of single metals, with caution to be exercised in the case of aluminum.

  17. Multichannel electrochemical microbial detection unit

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Young, R. N.; Boykin, E. H.

    1978-01-01

    The paper describes the design and capabilities of a compact multichannel electrochemical unit devised to detect and automatically indicate detection time length of bacteria. By connecting this unit to a strip-chart recorder, a permanent record is obtained of the end points and growth curves for each of eight channels. The experimental setup utilizing the multichannel unit consists of a test tube (25 by 150 mm) containing a combination redox electrode plus 18 ml of lauryl tryptose broth and positioned in a 35-C water bath. Leads from the electrodes are connected to the multichannel unit, which in turn is connected to a strip-chart recorder. After addition of 2.0 ml of inoculum to the test tubes, depression of the push-button starter activates the electronics, timer, and indicator light for each channel. The multichannel unit is employed to test tenfold dilutions of various members of the Enterobacteriaceae group, and a typical dose-response curve is presented.

  18. Charge Noise in Organic Electrochemical Transistors

    NASA Astrophysics Data System (ADS)

    Stoop, Ralph L.; Thodkar, Kishan; Sessolo, Michele; Bolink, Henk J.; Schönenberger, Christian; Calame, Michel

    2017-01-01

    Organic electrochemical transistors (OECTs) are increasingly studied as transducers in sensing applications. While much emphasis has been placed on analyzing and maximizing the OECT signal, noise has been mostly ignored, although it determines the resolution of the sensor. The major contribution to the noise in sensing devices is the 1 /f noise, dominant at low frequency. In this work, we demonstrate that the 1 /f noise in OECTs follows a charge-noise model, which reveals that the noise is due to charge fluctuations in proximity or within the bulk of the channel material. We present the noise scaling behavior with gate voltage, channel dimensions, and polymer thickness. Our results suggest the use of large area channels in order to maximize the signal-to-noise ratio (SNR) for biochemical and electrostatic sensing applications. A comparison with the literature shows that the magnitude of the noise in OECTs is similar to that observed in graphene transistors, and only slightly higher than that found in carbon nanotubes and silicon nanowire devices. In a model ion-sensing experiment with OECTs, we estimate crucial parameters such as the characteristic SNR and the corresponding limit of detection.

  19. Electrochemical processing of nitrate waste solutions

    SciTech Connect

    Genders, D.; Weinberg, N.; Hartsough, D. )

    1992-10-07

    The second phase of research performed at The Electrosynthesis Co., Inc. has demonstrated the successful removal of nitrite and nitrate from a synthetic effluent stream via a direct electrochemical reduction at a cathode. It was shown that direct reduction occurs at good current efficiencies in 1,000 hour studies. The membrane separation process is not readily achievable for the removal of nitrites and nitrates due to poor current efficiencies and membrane stability problems. A direct reduction process was studied at various cathode materials in a flow cell using the complete synthetic mix. Lead was found to be the cathode material of choice, displaying good current efficiencies and stability in short and long term tests under conditions of high temperature and high current density. Several anode materials were studied in both undivided and divided cell configurations. A divided cell configuration was preferable because it would prevent re-oxidation of nitrite by the anode. The technical objective of eliminating electrode fouling and solids formation was achieved although anode materials which had demonstrated good stability in short term divided cell tests corroded in 1,000 hour experiments. The cause for corrosion is thought to be F[sup [minus

  20. High damage tolerance of electrochemically lithiated silicon

    PubMed Central

    Wang, Xueju; Fan, Feifei; Wang, Jiangwei; Wang, Haoran; Tao, Siyu; Yang, Avery; Liu, Yang; Beng Chew, Huck; Mao, Scott X.; Zhu, Ting; Xia, Shuman

    2015-01-01

    Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. Here we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries. PMID:26400671

  1. Electrochemical oxidation of perfluorinated compounds in water.

    PubMed

    Niu, Junfeng; Li, Yang; Shang, Enxiang; Xu, Zesheng; Liu, Jinzi

    2016-03-01

    Perfluorinated compounds (PFCs) are persistent and refractory organic pollutants that have been detected in various environmental matrices and municipal wastewater. Electrochemical oxidation (EO) is a promising remediation technique for wastewater contaminated with PFCs. A number of recent studies have demonstrated that the "non-active" anodes, including boron-doped diamond, tin oxide, and lead dioxide, are effective in PFCs elimination in wastewater due to their high oxygen evolution potential. Many researchers have conducted experiments to investigate the optimal conditions (i.e., potential, current density, pH value, plate distance, initial PFCs concentration, electrolyte, and other factors) for PFCs elimination to obtain the maximal elimination efficiency and current efficiency. The EO mechanism and pathways of PFCs have been clearly elucidated, which undergo electron transfer, Kolbe decarboxylation or desulfonation, hydrolysis, and radical reaction. In addition, the safety evaluation and energy consumption evaluation of the EO technology have also been summarized to decrease toxic ion release from electrode and reduce the cost of this technique. Although the ultrasonication and hydrothermal techniques combined with the EO process can improve the removal efficiency and current efficiency significantly, these coupled techniques have not been commercialized and applied in industrial wastewater treatment. Finally, key challenges facing EO technology are listed and the directions for further research are pointed out (such as combination with other techniques, treatment for natural waters contaminated by low levels of PFCs, and reactor design).

  2. Current Density Scaling in Electrochemical Flow Capacitors

    SciTech Connect

    Hoyt, NC; Wainright, JS; Savinell, RF

    2015-02-18

    Electrochemical flow capacitors (EFCs) are a recently developed energy storage technology. One of the principal performance metrics of an EFC is the steady-state electrical current density that it can accept or deliver. Numerical models exist to predict this performance for specific cases, but here we present a study of how the current varies with respect to the applied cell voltage, flow rate, cell dimensions, and slurry properties using scaling laws. The scaling relationships are confirmed by numerical simulations and then subsequently by comparison to results from symmetric cell EFC experiments. This modeling approach permits the delimitation of three distinct operational regimes dependent on the values of two nondimensional combinations of the pertinent variables (specifically, a capacitive Graetz number and a conductivity ratio). Lastly, the models and nondimensional numbers are used to provide design guidance in terms of criteria for proper EFC operation. (C) The Author(s) 2015. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited. All rights reserved.

  3. High damage tolerance of electrochemically lithiated silicon

    DOE PAGES

    Wang, Xueju; Fan, Feifei; Wang, Jiangwei; ...

    2015-09-24

    Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. In this paper, we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratiomore » is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Finally, our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries.« less

  4. High damage tolerance of electrochemically lithiated silicon

    SciTech Connect

    Wang, Xueju; Fan, Feifei; Wang, Jiangwei; Wang, Haoran; Tao, Siyu; Yang, Avery; Liu, Yang; Beng Chew, Huck; Mao, Scott X.; Zhu, Ting; Xia, Shuman

    2015-09-24

    Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro–chemo–mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. In this paper, we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Finally, our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries.

  5. High damage tolerance of electrochemically lithiated silicon.

    PubMed

    Wang, Xueju; Fan, Feifei; Wang, Jiangwei; Wang, Haoran; Tao, Siyu; Yang, Avery; Liu, Yang; Beng Chew, Huck; Mao, Scott X; Zhu, Ting; Xia, Shuman

    2015-09-24

    Mechanical degradation and resultant capacity fade in high-capacity electrode materials critically hinder their use in high-performance rechargeable batteries. Despite tremendous efforts devoted to the study of the electro-chemo-mechanical behaviours of high-capacity electrode materials, their fracture properties and mechanisms remain largely unknown. Here we report a nanomechanical study on the damage tolerance of electrochemically lithiated silicon. Our in situ transmission electron microscopy experiments reveal a striking contrast of brittle fracture in pristine silicon versus ductile tensile deformation in fully lithiated silicon. Quantitative fracture toughness measurements by nanoindentation show a rapid brittle-to-ductile transition of fracture as the lithium-to-silicon molar ratio is increased to above 1.5. Molecular dynamics simulations elucidate the mechanistic underpinnings of the brittle-to-ductile transition governed by atomic bonding and lithiation-induced toughening. Our results reveal the high damage tolerance in amorphous lithium-rich silicon alloys and have important implications for the development of durable rechargeable batteries.

  6. Mediated electrochemical hazardous waste destruction

    SciTech Connect

    Hickman, R.G.; Farmer, J.C.; Wang, F.T.

    1991-08-01

    There are few permitted processes for mixed waste (radioactive plus chemically hazardous) treatment. We are developing electrochemical processes that convert the toxic organic components of mixed waste to water, carbon dioxide, an innocuous anions such as chloride. Aggressive oxidizer ions such as Ag{sup 2+} or Ce{sup +4} are produced at an anode. These can attack the organic molecules directly. They can also attack water which yields hydroxyl free radicals that in turn attack the organic molecules. The condensed (i.e., solid and/or liquid) effluent streams contain the inorganic radionuclide forms. These may be treated with existing technology and prepared for final disposal. Kinetics and the extent of destruction of some toxic organics have been measured. Depending on how the process is operated, coulombic efficiency can be nearly 100%. In addition, hazardous organic materials are becoming very expensive to dispose of and when they are combined with transuranic radioactive elements no processes are presently permitted. Mediated electrochemical oxidation is an ambient-temperature aqueous-phase process that can be used to oxidize organic components of mixed wastes. Problems associated with incineration, such as high-temperature volatilization of radionuclides, are avoided. Historically, Ag (2) has been used as a mediator in this process. Fe(6) and Co(3) are attractive alternatives to Ag(2) since they form soluble chlorides during the destruction of chlorinated solvents. Furthermore, silver itself is a toxic heavy metal. Quantitative data has been obtained for the complete oxidation of ethylene glycol by Fe(6) and Co(3). Though ethylene glycol is a nonhalogenated organic, this data has enabled us to make direct comparisons of activities of Fe(6) and Co(3) with Ag(2). Very good quantitative data for the oxidation of ethylene glycol by Ag(2) had already been collected. 4 refs., 6 figs.

  7. Electrochemical Measurement of Atmospheric Corrosion

    NASA Technical Reports Server (NTRS)

    DeArmond, Anna H.; Davis, Dennis D.; Beeson, Harold D.

    1999-01-01

    Corrosion of Shuttle thruster components in atmospheres containing high concentrations of nitrogen tetroxide (NTO) and water is an important issue in ground operations of bipropellant systems in humid locations. Measurements of the corrosivities of NTO-containing atmospheres and the responses of different materials to these atmospheres have been accomplished using an electrochemical sensor. The sensor is composed of alternating aluminum/titanium strips separated by thin insulating layers. Under high humidity conditions a thin film of water covers the surface of the sensor. Added NTO vapor reacts with the water film to form a conductive medium and establishes a galvanic cell. The current from this cell can be integrated with respect to time and related to the corrosion activity. The surface layer formed from humid air/NTO reacts in the same way as an aqueous solution of nitric acid. Nitric acid is generally considered an important agent in NTO corrosion situations. The aluminum/titanium sensor is unresponsive to dry air, responds slightly to humid air (> 75% RH), and responds strongly to the combination of humid air and NTO. The sensor response is a power function (n = 2) of the NTO concentration. The sensor does not respond to NTO in dry air. The response of other materials in this type of sensor is related to position of the material in a galvanic series in aqueous nitric acid. The concept and operation of this electrochemical corrosion measurement is being applied to other corrosive atmospheric contaminants such as hydrogen chloride, hydrogen fluoride, sulfur dioxide, and acidic aerosols.

  8. Electrochemical studies at high pressure

    SciTech Connect

    Cruanes, M.T.

    1993-01-01

    This research has dealt with the development and application of a methodology that permits electrochemical measurements at high pressure. The initial efforts focused on the design and construction of an electrochemical cell functional at hydrostatic pressures as high as 10 kbar. This cell was equipped with an Ag/AgCl/KCl (0.1M) reference electrode which provides reliable control of the potential at all pressures. The potential of this reference electrode can be considered to be constant with pressure. Measurements of formal potentials (E[degrees][prime]) of several transition-metal complexes vs the Ag/AgCl electrode rendered volumes of reactions whose magnitudes support the prediction of the negligible pressure dependence of the reference electrode. The main systems that have been investigated at high pressure are surface-modified electrodes. The author studied the effect of compression on the dynamics of charge transport in quaternized poly(4-vinylpyridine) (QPVP) films placed on gold electrodes, loaded with potassium ferricyanide, and equilibrated in potassium nitrate. Pressure accomplished the continuous change in the structure of the polymer network. This change causes a pronounced restriction in the propagation of charge and in the motion of mass. This high-pressure methodology has also allowed the spatial characterization of electron transfer events taking place between a gold electrode and ferrocene molecules covalently attached to the end of 1-undodecanethiol chains self-assembled on the electrode surface. The volumes of reaction and activation for the oxidation process are both positive, indicating that a volume expansion is associated with the formation of ferricinium. A model is proposed in which the creation of a vacancy in the self-assembled monolayer, for the accommodation of the ferricinium ion or a charge-compensating anion, is coupled with the electron transfer step.

  9. Process for electrochemically gasifying coal using electromagnetism

    DOEpatents

    Botts, Thomas E.; Powell, James R.

    1987-01-01

    A process for electrochemically gasifying coal by establishing a flowing stream of coal particulate slurry, electrolyte and electrode members through a transverse magnetic field that has sufficient strength to polarize the electrode members, thereby causing them to operate in combination with the electrolyte to electrochemically reduce the coal particulate in the slurry. Such electrochemical reduction of the coal produces hydrogen and carbon dioxide at opposite ends of the polarized electrode members. Gas collection means are operated in conjunction with the process to collect the evolved gases as they rise from the slurry and electrolyte solution.

  10. Chemically modified graphite for electrochemical cells

    DOEpatents

    Greinke, Ronald Alfred; Lewis, Irwin Charles

    1998-01-01

    This invention relates to chemically modified graphite particles: (a) that are useful in alkali metal-containing electrode of a electrochemical cell comprising: (i) the electrode, (ii) a non-aqueous electrolytic solution comprising an organic aprotic solvent which solvent tends to decompose when the electrochemical cell is in use, and an electrically conductive salt of an alkali metal, and (iii) a counterelectrode; and (b) that are chemically modified with fluorine, chlorine, iodine or phosphorus to reduce such decomposition. This invention also relates to electrodes comprising such chemically modified graphite and a binder and to electrochemical cells containing such electrodes.

  11. Chemically modified graphite for electrochemical cells

    DOEpatents

    Greinke, R.A.; Lewis, I.C.

    1998-05-26

    This invention relates to chemically modified graphite particles: (a) that are useful in alkali metal-containing electrode of a electrochemical cell comprising: (1) the electrode, (2) a non-aqueous electrolytic solution comprising an organic aprotic solvent which solvent tends to decompose when the electrochemical cell is in use, and an electrically conductive salt of an alkali metal, and (3) a counter electrode; and (b) that are chemically modified with fluorine, chlorine, iodine or phosphorus to reduce such decomposition. This invention also relates to electrodes comprising such chemically modified graphite and a binder and to electrochemical cells containing such electrodes. 3 figs.

  12. Coupling of Mechanical Behavior of Lithium Ion Cells to Electrochemical-Thermal Models for Battery Crush; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Pesaran, Ahmad; Zhang, Chao; Santhanagopalan, Shriram; Sahraei, Elham; Wierzbiki, Tom

    2015-06-15

    Propagation of failure in lithium-ion batteries during field events or under abuse is a strong function of the mechanical response of the different components in the battery. Whereas thermal and electrochemical models that capture the abuse response of batteries have been developed and matured over the years, the interaction between the mechanical behavior and the thermal response of these batteries is not very well understood. With support from the Department of Energy, NREL has made progress in coupling mechanical, thermal, and electrochemical lithium-ion models to predict the initiation and propagation of short circuits under external crush in a cell. The challenge with a cell crush simulation is to estimate the magnitude and location of the short. To address this, the model includes an explicit representation of each individual component such as the active material, current collector, separator, etc., and predicts their mechanical deformation under different crush scenarios. Initial results show reasonable agreement with experiments. In this presentation, the versatility of the approach for use with different design factors, cell formats and chemistries is explored using examples.

  13. Electrochemical atomic layer deposition of copper nanofilms on ruthenium

    NASA Astrophysics Data System (ADS)

    Gebregziabiher, Daniel K.; Kim, Youn-Geun; Thambidurai, Chandru; Ivanova, Valentina; Haumesser, Paul-Henri; Stickney, John L.

    2010-04-01

    As ULSI scales to smaller and smaller dimensions, it has become necessary to form layers of materials only a few nm thick. In addition, trenches are now being incorporated in ULSI formation which require conformal coating and will not be amenable to CMP. Atomic layer deposition (ALD) is being developed to address such issues. ALD is the formation of materials layer by layer using self-limiting reactions. This article describes the formation of Cu seed layers (for the Cu damascene process) on a Ru barrier layer. The deposit was formed by the electrochemical analog of ALD, using electrochemical self-limiting reactions which are referred to as underpotential deposition (UPD). Monolayer restricted galvanic displacement was used to form atomic layers of Cu. First Pb UPD was deposited, forming a sacrificial layer, and then a Cu +2 solution was flushed into the cell and Pb was exchanged for Cu. A linear dependence was shown for Cu growth over 8 ALD cycles, and STM showed a conformal deposition, as expected for an ALD process. Relative Cu coverages were determined using Auger electron spectroscopy, while absolute Cu coverages were obtained from coulometry during oxidative stripping of the deposits. Use of a Cl - containing electrolyte results in Cu deposits covered with an atomic layer of Cl atoms, which have been shown to protect the surfaced from oxidation during various stages of the deposition process. The 10 nm thick Ru substrates were formed on Si(1 0 0) wafers, and were partially oxidized upon receipt. Electrochemical reduction, prior to Cu deposition, removed the oxygen and some traces of carbon, the result of transport. Ion bombardment proved to clean all oxygen and carbon traces from the surface.

  14. A Comparison of Single-Wall Carbon Nanotube Electrochemical Capacitor Electrode Fabrication Methods

    DTIC Science & Technology

    2012-01-24

    REPORT A comparison of single-wall carbon nanotube electrochemical capacitor electrode fabrication methods 14. ABSTRACT 16. SECURITY CLASSIFICATION OF... Carbon nanotubes (CNTs) are being widely investigated as a replacement for activated carbon in super- capacitors. A wide range of CNT specific...ORGANIZATION NAMES AND ADDRESSES U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Carbon nanotube

  15. Frequency addressable beams for land mobile communications

    NASA Technical Reports Server (NTRS)

    Thompson, J. D.; Dubellay, G. G.

    1988-01-01

    Satellites used for mobile communications need to serve large numbers of small, low cost terminals. The most important parameters affecting the capacity of such systems are the satellite equivalent isotropically radiated power (EIRP) and gain to noise temperature ratio (G/T) and available bandwidth. Satellites using frequency addressed beams provide high EIRP and G/T with high-gain antenna beams that also permit frequency reuse over the composite coverage area. Frequency addressing is easy to implement and compatible with low-cost terminals and offers higher capacity than alternative approaches.

  16. Shared address collectives using counter mechanisms

    DOEpatents

    Blocksome, Michael; Dozsa, Gabor; Gooding, Thomas M; Heidelberger, Philip; Kumar, Sameer; Mamidala, Amith R; Miller, Douglas

    2014-02-18

    A shared address space on a compute node stores data received from a network and data to transmit to the network. The shared address space includes an application buffer that can be directly operated upon by a plurality of processes, for instance, running on different cores on the compute node. A shared counter is used for one or more of signaling arrival of the data across the plurality of processes running on the compute node, signaling completion of an operation performed by one or more of the plurality of processes, obtaining reservation slots by one or more of the plurality of processes, or combinations thereof.

  17. Cheaper Adjoints by Reversing Address Computations

    DOE PAGES

    Hascoët, L.; Utke, J.; Naumann, U.

    2008-01-01

    The reverse mode of automatic differentiation is widely used in science and engineering. A severe bottleneck for the performance of the reverse mode, however, is the necessity to recover certain intermediate values of the program in reverse order. Among these values are computed addresses, which traditionally are recovered through forward recomputation and storage in memory. We propose an alternative approach for recovery that uses inverse computation based on dependency information. Address storage constitutes a significant portion of the overall storage requirements. An example illustrates substantial gains that the proposed approach yields, and we show use cases in practical applications.

  18. Bismuth-based electrochemical stripping analysis

    DOEpatents

    Wang, Joseph

    2004-01-27

    Method and apparatus for trace metal detection and analysis using bismuth-coated electrodes and electrochemical stripping analysis. Both anodic stripping voltammetry and adsorptive stripping analysis may be employed.

  19. DECHLORINATION OF TRICHLOROETHYLENE USING ELECTROCHEMICAL METHODS

    EPA Science Inventory

    Electrochemical degradation (ECD) is used to decontaminate organic and inorganic contaminants through oxidative or reductive processes. The ECD of Trichloroethylene (TCE) dechlorinates TCE through electric reduction. TCE dechlorination presented in the literature utilized electro...

  20. Space Electrochemical Research and Technology. Abstracts

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This document contains abstracts of the proceedings of NASA's fifth Space Electrochemical Research and Technology (SERT) Conference, held at the NASA Lewis Research Center on May 1-3, 1995. The objective of the conference was to assess the present status and general thrust of research and development in those areas of electrochemical technology required to enable NASA missions into the next century. The conference provided a forum for the exchange of ideas and opinions of those actively involved in the field, in order to define new opportunities for the application of electrochemical processes in future NASA missions. Papers were presented in three technical areas: (1) the electrochemical interface, (2) the next generation in aerospace batteries and fuel cells, and (3) electrochemistry for non-energy storage applications. This document contains the abstracts of the papers presented.

  1. Electrochemical Sensors Based on Carbon Nanotubes

    PubMed Central

    Saleh Ahammad, A. J.; Lee, Jae-Joon; Rahman, Md. Aminur

    2009-01-01

    This review focuses on recent contributions in the development of the electrochemical sensors based on carbon nanotubes (CNTs). CNTs have unique mechanical and electronic properties, combined with chemical stability, and behave electrically as a metal or semiconductor, depending on their structure. For sensing applications, CNTs have many advantages such as small size with larger surface area, excellent electron transfer promoting ability when used as electrodes modifier in electrochemical reactions, and easy protein immobilization with retention of its activity for potential biosensors. CNTs play an important role in the performance of electrochemical biosensors, immunosensors, and DNA biosensors. Various methods have been developed for the design of sensors using CNTs in recent years. Herein we summarize the applications of CNTs in the construction of electrochemical sensors and biosensors along with other nanomaterials and conducting polymers. PMID:22574013

  2. Rechargeable thin-film electrochemical generator

    DOEpatents

    Rouillard, Roger; Domroese, Michael K.; Hoffman, Joseph A.; Lindeman, David D.; Noel, Joseph-Robert-Gaetan; Radewald, Vern E.; Ranger, Michel; Sudano, Anthony; Trice, Jennifer L.; Turgeon, Thomas A.

    2000-09-15

    An improved electrochemical generator is disclosed. The electrochemical generator includes a thin-film electrochemical cell which is maintained in a state of compression through use of an internal or an external pressure apparatus. A thermal conductor, which is connected to at least one of the positive or negative contacts of the cell, conducts current into and out of the cell and also conducts thermal energy between the cell and thermally conductive, electrically resistive material disposed on a vessel wall adjacent the conductor. The thermally conductive, electrically resistive material may include an anodized coating or a thin sheet of a plastic, mineral-based material or conductive polymer material. The thermal conductor is fabricated to include a resilient portion which expands and contracts to maintain mechanical contact between the cell and the thermally conductive material in the presence of relative movement between the cell and the wall structure. The electrochemical generator may be disposed in a hermetically sealed housing.

  3. System and method for networking electrochemical devices

    DOEpatents

    Williams, Mark C.; Wimer, John G.; Archer, David H.

    1995-01-01

    An improved electrochemically active system and method including a plurality of electrochemical devices, such as fuel cells and fluid separation devices, in which the anode and cathode process-fluid flow chambers are connected in fluid-flow arrangements so that the operating parameters of each of said plurality of electrochemical devices which are dependent upon process-fluid parameters may be individually controlled to provide improved operating efficiency. The improvements in operation include improved power efficiency and improved fuel utilization in fuel cell power generating systems and reduced power consumption in fluid separation devices and the like through interstage process fluid parameter control for series networked electrochemical devices. The improved networking method includes recycling of various process flows to enhance the overall control scheme.

  4. Battery electrochemical nonlinear/dynamic SPICE model

    SciTech Connect

    Glass, M.C.

    1996-12-31

    An Integrated Battery Model has been produced which accurately represents DC nonlinear battery behavior together with transient dynamics. The NiH{sub 2} battery model begins with a given continuous-function electrochemical math model. The math model for the battery consists of the sum of two electrochemical process DC currents, which are a function of the battery terminal voltage. This paper describes procedures for realizing a voltage-source SPICE model which implements the electrochemical equations using behavioral sources. The model merges the essentially DC non-linear behavior of the electrochemical model, together with the empirical AC dynamic terminal impedance from measured data. Thus the model integrates the short-term linear impedance behavior, with the long-term nonlinear DC resistance behavior. The long-duration non-Faradaic capacitive behavior of the battery is represented by a time constant. Outputs of the model include battery voltage/current, state-of-charge, and charge-current efficiency.

  5. Dechlorination by combined electrochemical reduction and oxidation.

    PubMed

    Cong, Yan-qing; Wu, Zu-cheng; Tan, Tian-en

    2005-06-01

    Chlorophenols are typical priority pollutants listed by USEPA (U.S. Environmental Protection Agency). The removal of chlorophenol could be carried out by a combination of electrochemical reduction and oxidation method. Results showed that it was feasible to degrade contaminants containing chlorine atoms by electrochemical reduction to form phenol, which was further degraded on the anode by electrochemical oxidation. Chlorophenol removal rate was more than 90% by the combined electrochemical reduction and oxidation at current of 6 mA and pH 6. The hydrogen atom is a powerful reducing agent that reductively dechlorinates chlorophenols. The instantaneous current efficiency was calculated and the results indicated that cathodic reduction was the main contributor to the degradation of chlorophenol.

  6. Electrochemical stiffness in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Tavassol, Hadi; Jones, Elizabeth M. C.; Sottos, Nancy R.; Gewirth, Andrew A.

    2016-11-01

    Although lithium-ion batteries are ubiquitous in portable electronics, increased charge rate and discharge power are required for more demanding applications such as electric vehicles. The high-rate exchange of lithium ions required for more power and faster charging generates significant stresses and strains in the electrodes that ultimately lead to performance degradation. To date, electrochemically induced stresses and strains in battery electrodes have been studied only individually. Here, a new technique is developed to probe the chemomechanical response of electrodes by calculating the electrochemical stiffness via coordinated in situ stress and strain measurements. We show that dramatic changes in electrochemical stiffness occur due to the formation of different graphite-lithium intercalation compounds during cycling. Our analysis reveals that stress scales proportionally with the lithiation/delithiation rate and strain scales proportionally with capacity (and inversely with rate). Electrochemical stiffness measurements provide new insights into the origin of rate-dependent chemomechanical degradation and the evaluation of advanced battery electrodes.

  7. Palladium deuteride formation in the cathode of an electrochemical cell: An in situ neutron diffraction study

    SciTech Connect

    Rotella, F.J.; Richardson, J.W. Jr.; Redey, L.; Felcher, G.P.; Hitterman, R.L.; Kleb, R.

    1991-12-31

    In this report, neutron diffraction of palladium cathodes is utilized to reveal palladium deuteride formation within the crystal structure of the metal. The experiment described in this report demonstrates the efficacy of neutron powder diffraction as a tool for structural studies of metal deuterides/hydrides and the feasibility of in situ diffraction measurements from a working electrochemical cell. (JL)

  8. Palladium deuteride formation in the cathode of an electrochemical cell: An in situ neutron diffraction study

    SciTech Connect

    Rotella, F.J.; Richardson, J.W. Jr.; Redey, L.; Felcher, G.P.; Hitterman, R.L.; Kleb, R.

    1991-01-01

    In this report, neutron diffraction of palladium cathodes is utilized to reveal palladium deuteride formation within the crystal structure of the metal. The experiment described in this report demonstrates the efficacy of neutron powder diffraction as a tool for structural studies of metal deuterides/hydrides and the feasibility of in situ diffraction measurements from a working electrochemical cell. (JL)

  9. ELECTROCHEMICAL DEGRADATION OF TRICHLOROETHYLENE USING GRANULAR-GRAPHITE ELECTRODES: IDENTIFICATION AND QUALIFICATION OF DECHLORINATION PRODUCTS

    EPA Science Inventory

    TCE was successfully dechlorinated in aqueous solution using granular graphite as the cathode in a mixed electrochemical reactor. In experiments with an initial TCE concentration of less than 100 mg/l, TCE was reduced approximately by 75% in the reactor under an applied cell volt...

  10. The Entrance and Exit Effects in Small Electrochemical Filter-Press Reactors Used in the Laboratory

    ERIC Educational Resources Information Center

    Frias-Ferrer, Angel; Gonzalez-Garcia, Jose; Saez, Veronica; Exposito, Eduardo; Sanchez-Sanchez, Carlos M.; Mantiel, Vicente; Walsh, Frank C.; Aldaz, Antonio; Walsh, Frank C.

    2005-01-01

    A laboratory experiment designed to examine the entrance and exit effects in small electrochemical filter-press reactors used in the laboratory is presented. The single compartment of the filter-press reactor is filled with different turbulence promoters to study their influence as compared to the empty configuration.

  11. Catalytic Hydrogenation of Organic Compounds without H2 Supply: An Electrochemical System

    ERIC Educational Resources Information Center

    Navarro, Daniela Maria do Amaral Ferraz; Navarro, Marcelo

    2004-01-01

    An experiment developed for an undergraduate organic chemistry laboratory course that can be used to introduce the catalytic hydrogenation reaction, catalysis electrochemical principles and gas chromatography is presented. The organic compounds hydrogenated by the electrocatalytic hydrogenation (ECH) process were styrene, benzaldehyde and…

  12. The Rise of Voltammetry: From Polarography to the Scanning Electrochemical Microscope

    ERIC Educational Resources Information Center

    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.

  13. Free Energies of Formation Measurements on Solid-State Electrochemical Cells

    ERIC Educational Resources Information Center

    Rollino, J. A.; Aronson, S.

    1972-01-01

    A simple experiment is proposed that can provide the student with some insight into the chemical properties of solids. It also demonstrates the relationship between the Gibbs free energy of formation of an ionic solid and the emf of an electrochemical cell. (DF)

  14. Anodized titanium and stainless steel in contact with CFRP: an electrochemical approach considering galvanic corrosion.

    PubMed

    Mueller, Yves; Tognini, Roger; Mayer, Joerg; Virtanen, Sannakaisa

    2007-09-15

    The combination of different materials in an implant gives the opportunity to better fulfill the requirements that are needed to improve the healing process. However, using different materials increases the risk of galvanic coupling corrosion. In this study, coupling effects of gold-anodized titanium, stainless steel for biomedical applications, carbon fiber reinforced polyetheretherketone (CFRP), and CFRP containing tantalum fibers are investigated electrochemically and by long-term immersion experiments in simulated body fluid (SBF). Potentiodynamic polarization experiments (i/E curves) and electrochemical impedance spectroscopy (EIS) of the separated materials showed a passive behavior of the metallic samples. Anodized titanium showed no corrosion attacks, whereas stainless steel is highly susceptibility for localized corrosion. On the other side, an active dissolution behavior of both of the CFRPs in the given environment could be determined, leading to delaminating of the carbon fibers from the matrix. Long-term immersion experiments were carried out using a set-up especially developed to simulate coupling conditions of a point contact fixator system (PC-Fix) in a biological environment. Electrochemical data were acquired in situ during the whole immersion time. The results of the immersion experiments correlate with the findings of the electrochemical investigation. Localized corrosion attacks were found on stainless steel, whereas anodized titanium showed no corrosion attacks. No significant differences between the two CFRP types could be found. Galvanic coupling corrosion in combination with crevice conditions and possible corrosion mechanisms are discussed.

  15. Electrochemical properties of imidazolium salt electrolytes for electrochemical capacitor applications

    SciTech Connect

    McEwen, A.B.; Ngo, H.L.; LeCompte, K.; Goldman, J.L.

    1999-05-01

    The specific ionic conductivity, dynamic viscosity, and electrochemical stability of several imidazolium salts are reported as neat ionic liquids and their solutions in several organic solvents. The temperature dependence of conductivity and viscosity are analyzed for 1-ethyl-3-methylimidazolium (EMI{sup +}) and 1,2-dimethyl-3-n-propylimidazolium (DMPI{sup +}) salts, and the influence of the anions bis(trifluoromethylsulfonyl)imide (Im{sup {minus}}), bis(perfluoroethylsulfonyl)imide (Beti{sup {minus}}), hexafluoroarsenate (AsF{sub 6}{sup {minus}}), hexafluorophosphate (PF{sub 6}{sup {minus}}), and tetrafluoroborate (BF{sub 4}{sup {minus}}) on these properties are discussed. These imidazolium salts make possible electrolytes with high concentration (>3 M), high room temperature conductivity (up to 60 mS/cm), and a wide window of stability (>4 V at 20 {micro}A/cm{sup 2}). Differential scanning calorimetric results confirm a large glass phase for the ionic liquids, with substantial (>80 C) supercooling. Thermal gravimetric results indicate the imidazolium salts with Im{sup {minus}} and Beti{sup {minus}} anions to be thermally more stable than the lithium salt analogs. The Vogel-Tammann-Fulcher interpretation accurately describes the conductivity temperature dependence.

  16. Multi-layer seal for electrochemical devices

    DOEpatents

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-11-16

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  17. Multi-layer seal for electrochemical devices

    DOEpatents

    Chou, Yeong-Shyung [Richland, WA; Meinhardt, Kerry D [Kennewick, WA; Stevenson, Jeffry W [Richland, WA

    2010-09-14

    Multi-layer seals are provided that find advantageous use for reducing leakage of gases between adjacent components of electrochemical devices. Multi-layer seals of the invention include a gasket body defining first and second opposing surfaces and a compliant interlayer positioned adjacent each of the first and second surfaces. Also provided are methods for making and using the multi-layer seals, and electrochemical devices including said seals.

  18. Low temperature thermally regenerative electrochemical system

    DOEpatents

    Loutfy, Raouf O.; Brown, Alan P.; Yao, Neng-Ping

    1983-01-01

    A thermally regenerative electrochemical system including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the complexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  19. Low-temperature thermally regenerative electrochemical system

    DOEpatents

    Loutfy, R.O.; Brown, A.P.; Yao, N.P.

    1982-04-21

    A thermally regenerative electrochemical system is described including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the ocmplexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

  20. Electrochemical Energy Storage Technical Team Roadmap

    SciTech Connect

    2013-06-01

    This U.S. DRIVE electrochemical energy storage roadmap describes ongoing and planned efforts to develop electrochemical energy storage technologies for plug-in electric vehicles (PEVs). The Energy Storage activity comprises a number of research areas (including advanced materials research, cell level research, battery development, and enabling R&D which includes analysis, testing and other activities) for advanced energy storage technologies (batteries and ultra-capacitors).