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Sample records for clearing electrodes tested

  1. Comparison of Enamel and Stainless Steel Electron Cloud Clearing Electrodes Tested in the CERN Proton Synchrotron

    CERN Document Server

    Caspers, Friedhelm; Mahner, C; Wendel, JC

    2010-01-01

    During the 2007 run with the nominal LHC proton beam, electron cloud has been clearly identified and characterized in the PS using a dedicated setup with shielded button-type pickups. Efficient electron cloud suppression could be achieved with a stainless steel stripline-type electrode biased to negative and positive voltages up to ± 1 kV. For the 2008 run, a second setup was installed in straight section 84 of the PS where the stainless steel was replaced by a stripline composed of an enamel insulator with a resistive coating. In contrast to ordinary stripline electrodes this setup presents a very low beam coupling impedance and could thus be envisaged for long sections of high-intensity machines. Here, we present first comparative measurements with this new type of enamel clearing electrode using the nominal LHC beam with 72 bunches and 25 ns bunch spacing.

  2. A New Type of distributed Enamel based Clearing Electrode

    CERN Document Server

    Kroyer, T; Caspers, Friedhelm; Hellmond, P; Métral, E; Wendel, J C; Zimmermann, F

    2007-01-01

    Clearing electrodes can be used for electron cloud (EC) suppression in high intensity particle accelerators. In this paper the use of low and highly resistive layers on a dielectric substrate are examined. The beam coupling impedance of such a structure is evaluated. Furthermore the clearing efficiency as well as technological issues are discussed.

  3. A split-electrode for clearing scattered electrons in the RHIC e-lens

    Energy Technology Data Exchange (ETDEWEB)

    Gu X.; Pikin, A.; Thieberger, P.; Fischer, W.; Hock, J.; Hamdi, K.; Gassner,D.; Luo, Y.; Montag, C.; Okamura, M.

    2012-05-20

    We are designing two electron lenses that will be installed at RHIC IR10 to compensate for the head-on beam-beam effect. To clear accumulated scattered electrons from 100 GeV proton-electron head-on collisions in the e-lens, a clearing split electrode may be constructed. The feasibility of this proposed electrode was demonstrated via the CST Particle Studio and Opera program simulations. By splitting one of the drift tubes in the e-lens and applying {approx} 380 V across the two parts, the scattered electrons can be cleared out within several hundred micro-seconds. At the same time we can restrict the unwanted shift of the primary electron-beam that already passed the 2-m interaction region in e-lens, to less than 15um.

  4. Testing of Electrodes, Cells and Short Stacks

    DEFF Research Database (Denmark)

    Hauch, Anne; Mogensen, Mogens Bjerg

    2017-01-01

    electrochemical measurements, and this will be the focus of this chapter. First, the important issue of understanding potential differences and measurements of potentials, which is linked to the choice of proper electrode geometries and test set up configurations for electrode and cell testing, is presented...

  5. A study of metalized electrode self-clearing in electroactive polymer (EAP) based actuators

    Science.gov (United States)

    Ahmed, Saad; Ounaies, Zoubeida

    2016-04-01

    Electroactive polymer (EAP) based technologies have shown promise in areas such as artificial muscles, actuator, aerospace, medical and soft robotics. Still challenges remain such as low induced forces and defects-driven electrical breakdown, which impede the practical implementation of this technology. Multilayered or stacked configuration can address the low induced force issue whereas self-clearing can be a technique to improve breakdown limit of EAP based actuators. Self-clearing refers to the partial local breakdown of dielectric medium due to the presence of impurities, which in turn results in the evaporation of some of the metalized electrode. After this evaporation, the impurity is cleared and any current path would be safely cut off, which means the actuator continues to perform. It is a widely studied concept in the capacitor community, while it has not been studied much for EAP technologies. In this paper we report a systematic approach to precondition a silver-metalized electroactive polymer (EAP), more specifically P(VDF-TrFE-CTFE) terpolymer, using self-clearing concept. First, we show improvement in the dielectric breakdown strength of EAP based unimorph actuators after pre-clearing the impurities using low electric field (lower than dielectric breakdown of the terpolymer). Inspired by this improvement, we used Weibull statistics to systematically estimate the self-clearing/ preconditioning field needed to clear the defects. Then electrical breakdown experiments are conducted with and without preconditioning the samples to investigate its effect on the breakdown strength of the sample.

  6. Advanced ThioClear process testing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lani, B.

    1998-03-01

    Wet scrubbing is the leading proven commercial post-combustion FGD technology available to meet the sulfur dioxide reductions required by the Clean Air Act Amendments. To reduce costs associated with wet FGD, Dravo Lime Company has developed the ThioClear process. ThioClear is an ex-situ forced oxidation magnesium-enhanced lime FGD process. ThioClear process differs from the conventional magnesium-enhanced lime process in that the recycle liquor has minimal suspended solids and the by-products are wallboard quality gypsum and magnesium hydroxide, an excellent reagent for water treatment. The process has demonstrated sulfur dioxide removal efficiencies of +95% in both a vertical spray scrubber tower and a horizontal absorber operating at gas velocities of 16 fps, respectively. This report details the optimization studies and associated economics from testing conducted at Dravo Lime Company`s pilot plant located at the Miami Fort Station of the Cincinnati Gas and Electric Company.

  7. The feasibility of bench tests for disposable ECG electrode adhesiveness.

    Science.gov (United States)

    Baker, C D; Schoenberg, A A; Booth, H E

    1979-01-01

    The feasibility of recommending one standard bench test that adequately qualifies electrode adhesives for clinical use was examined by UBTL. Small strips, cut from whole, commercially available disposable ECG electrodes, were attached to three types of surfaces, and samples of each type of electrode were peel tested at 15 minutes, 8 hours, and 48 hours after attachment. A program was developed to average, display, and calculate peel strength parameters. Analysis of the data showed that (a) the peel strength of electrodes varied by more than a factor of 10 when measured on human skin, and by more than a factor of 3 when measured on bench test surfaces, and (b) the peel strength of the electrode adhesive strips did not correlate with intact electrode loss on ambulatory subjects. Therefore, UBTL could not recommend one bench test that would measure adhesion performance for all electrode types appropriate for inclusion in an AAMI ECG electrode standard.

  8. Performance of the DTL electrode compared to the jet contact lens electrode in clinical testing.

    Science.gov (United States)

    Yin, Hang; Pardue, Machelle T

    2004-01-01

    To compare the recording characteristics of the DTL fiber and Jet contact lens electrodes, ERG responses were recorded from 20 normal subjects using the ISCEV standard clinical protocol. In each subject, the DTL electrode was placed in the right eye and the Jet contact lens in the left eye after 30 min of dark-adaptation. After presenting standard dark- and light-adapted stimuli, each response was analyzed for a- and b-wave amplitude and implicit time. Each subject was then asked to rate the comfort of each electrode. Responses recorded with the DTL are larger and faster for the dark-adapted dim white and red flashes. In contrast, the Jet electrode records larger responses for the dark-adapted standard flash and light-adapted flashes. Of these differences, only the standard flash is statistically significant. However, overall the DTL electrode has greater variability than the Jet electrode across all recordings. The DTL and Jet electrodes cannot be used interchangeably as demonstrated by a Bland and Altman analysis of agreement. Thus, separate normative values need to be collected for each type of electrode to accurately assess retinal function. Based on the comfort assessment of the two electrodes, the subjects preferred the DTL electrode over the Jet electrode. Due to the superior comfort level of the DTL and its similarities to the Jet contact lens electrode in ERG recordings, the DTL electrode appears to be a good alternative to the Jet electrode in routine clinical testing when used with the appropriate normative values.

  9. Electrode holder useful in a corrosion testing device

    Science.gov (United States)

    Murphy, Jr., Robert J.; Jamison, Dale E.

    1986-01-01

    The present invention is directed to an apparatus and method for holding one or more test electrodes of precisely known exposed surface area. The present invention is particularly useful in a device for determining the corrosion properties of the materials from which the test electrodes have been formed. The present invention relates to a device and method for holding the described electrodes wherein the exposed surface area of the electrodes is only infinitesimally decreased. Further, in the present invention the exposed, electrically conductive surface area of the contact devices is small relative to the test electrode surface area. The holder of the present invention conveniently comprises a device for contacting and engaging each test electrode at two point contacts infinitesimally small in relation to the exposed surface area of the electrodes.

  10. Tests of the presampler electrodes for module 0

    CERN Document Server

    Belymam, A; Hoummada, A; Lund-Jensen, B

    2000-01-01

    The ATLAS presampler will be composed of approximately 90000 printed circuit board electrodes. These electrodes need to be tested to verify that they are whithin the tight thickness and size tolerances required by the module production technique. For the 3-layer anode electrodes a measurement of the electrical properties is required. A testbench to automatize these electrical measurements has been developed at KTH. This note presents the results obtained from measurements of thickness, size and electrical properties of the electrodes for the first series produced sectors, "module 0" . The thickness requirements are well fulfiled on 2-layer cathode electrodes. A large fraction of the 3-layer anode electrodes did not meet the thickness specifications. The reasons for this are identified and several improvements of the manufacturing process are proposed. The quality of the contour cutting of the boards is examined on preseries cut by milling and preseries cut by punching. Measurements show that the precision of ...

  11. Development of standard test methods for evaluating defibrillation recovery characteristics of disposable ECG electrodes.

    Science.gov (United States)

    Schoenberg, A A; Booth, H E; Lyon, P C

    1979-01-01

    A clinically relevant test for the measurement of defibrillation overload recovery of prefilled disposable ECG electrodes was developed and is proposed for use in an ECG electrode standard under development by AAMI. Defibrillation overload voltages and currents, as well as electrode polarization recovery voltages, were first measured in animal tests on 12 types of electrodes to allow correlation with various bench tests using a capacitor discharge at 10, 200, or 1000 V. Current overloads absorbed by the electrodes under worst conditions in animal tests were in the range of 2 percent of the defibrillation current flowing through the chest. These overloads were absorbed by most Ag-AgCl electrodes without excessive polarization. However, stainless steel, brass, and tin electrodes tended to polarize to levels that would saturate many ECG monitors. A standard bench test using a 200-V 10-muF capacitor was recommended for inclusion in the AAMI standard to determine whether electrodes are acceptable for use during defibrillation.

  12. Component-Level Electronic-Assembly Repair (CLEAR) Synthetic Instrument Capabilities Assessment and Test Report

    Science.gov (United States)

    Oeftering, Richard C.; Bradish, Martin A.

    2011-01-01

    The role of synthetic instruments (SIs) for Component-Level Electronic-Assembly Repair (CLEAR) is to provide an external lower-level diagnostic and functional test capability beyond the built-in-test capabilities of spacecraft electronics. Built-in diagnostics can report faults and symptoms, but isolating the root cause and performing corrective action requires specialized instruments. Often a fault can be revealed by emulating the operation of external hardware. This implies complex hardware that is too massive to be accommodated in spacecraft. The SI strategy is aimed at minimizing complexity and mass by employing highly reconfigurable instruments that perform diagnostics and emulate external functions. In effect, SI can synthesize an instrument on demand. The SI architecture section of this document summarizes the result of a recent program diagnostic and test needs assessment based on the International Space Station. The SI architecture addresses operational issues such as minimizing crew time and crew skill level, and the SI data transactions between the crew and supporting ground engineering searching for the root cause and formulating corrective actions. SI technology is described within a teleoperations framework. The remaining sections describe a lab demonstration intended to show that a single SI circuit could synthesize an instrument in hardware and subsequently clear the hardware and synthesize a completely different instrument on demand. An analysis of the capabilities and limitations of commercially available SI hardware and programming tools is included. Future work in SI technology is also described.

  13. Graphite electrode arc melter demonstration Phase 2 test results

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; O`Connor, W.K.; Oden, L.L.; Turner, P.C.

    1996-06-01

    Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau`s Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of {open_quotes}as-received{close_quotes} heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process.

  14. Testing the Two-Layer Model for Correcting Clear Sky Reflectance near Clouds

    Science.gov (United States)

    Wen, Guoyong; Marshak, Alexander; Evans, Frank; Varnai, Tamas; Levy, Rob

    2015-01-01

    A two-layer model (2LM) was developed in our earlier studies to estimate the clear sky reflectance enhancement due to cloud-molecular radiative interaction at MODIS at 0.47 micrometers. Recently, we extended the model to include cloud-surface and cloud-aerosol radiative interactions. We use the LES/SHDOM simulated 3D true radiation fields to test the 2LM for reflectance enhancement at 0.47 micrometers. We find: The simple model captures the viewing angle dependence of the reflectance enhancement near cloud, suggesting the physics of this model is correct; the cloud-molecular interaction alone accounts for 70 percent of the enhancement; the cloud-surface interaction accounts for 16 percent of the enhancement; the cloud-aerosol interaction accounts for an additional 13 percent of the enhancement. We conclude that the 2LM is simple to apply and unbiased.

  15. A clearing house for diagnostic testing: the solution to ensure access to and use of patented genetic inventions?

    Science.gov (United States)

    van Zimmeren, Esther; Verbeure, Birgit; Matthijs, Gert; Van Overwalle, Geertrui

    2006-01-01

    In genetic diagnostics, the emergence of a so-called "patent thicket" is imminent. Such an overlapping set of patent rights may have restrictive effects on further research and development of diagnostic tests, and the provision of clinical diagnostic services. Currently, two models that may facilitate access to and use of patented genetic inventions are attracting much debate in various national and international fora: patent pools and clearing houses. In this article, we explore the concept of clearing houses. Several types of clearing houses are identified. First, we describe and discuss two types that would provide access to information on the patented inventions: the information clearing house and the technology exchange clearing house. Second, three types of clearing houses are analysed that not only offer access to information but also provide an instrument to facilitate the use of the patented inventions: the open access clearing house, the standardized licences clearing house and the royalty collection clearing house. A royalty collection clearing house for genetic diagnostic testing would be the most comprehensive as it would serve several functions: identifying patents and patent claims essential to diagnostic testing, matching licensees with licensors, developing and supplying standardized licences, collecting royalties, monitoring whether users respect licensing conditions, and providing dispute resolution services such as mediation and arbitration. In this way, it might function as an effective model for users to facilitate access to and use of the patented inventions. However, it remains to be seen whether patent holders with a strong patent portfolio will be convinced by the advantages of the royalty collection clearing house and be willing to participate. PMID:16710543

  16. Clear & Simple

    Science.gov (United States)

    ... Cultural Respect Language Access Talking to Your Doctor Research Underway Plain Language Clear & Simple What is Clear & Simple? Clear & Simple ... schedule? A: Pretesting need not be an elaborate, time-consuming research project and depends on: How quickly you work, ...

  17. ENOBIO - First tests of a dry electrophysiology electrode using carbon nanotubes

    CERN Document Server

    Ruffini, G; Farres, E; Watts, P C P; Mendoza, Eric; Silva, R; Grau, C; Marco-Pallares, J; Fuentemilla, L; Vanfleteren, J; De Moor, P; Van de Casteele, B; Ruffini, Giulio; Dunne, Stephen; Farres, Esteve; Watts, Paul C. P.; Mendoza, Ernest; Silva, Ravi; Grau, Carles; Marco-Pallares, Josep; Fuentemilla, Lluis; Vanfleteren, Jan; Moor, Piet De; Vandecasteele, Bjorn

    2006-01-01

    We describe the development and first tests of Enobio, a dry electrode sensor concept for biopotential applications. In the proposed electrodes, the tip of the electrode is covered with a forest of multi-walled CNTs that will be coated with Ag/AgCl to provide ionic-electronic transduction. The CNT brush-like structure is to penetrate the outer layers of the skin improving electrical contact as well as increae the contact surface area. In this paper, we report the results of the first tests of this concept -- immersion on saline solution and pig skin signal detection. These indicate performance on a par with state of the art research-oriented wet electrodes.

  18. ENOBIO - first tests of a dry electrophysiology electrode using carbon nanotubes.

    Science.gov (United States)

    Ruffini, Giulio; Dunne, Stephen; Farrés, Esteve; Watts, Paul C P; Mendoza, Ernest; Silva, S Ravi P; Grau, Carles; Marco-Pallarés, Josep; Fuentemilla, Lluís; Vandecasteele, B Jorn

    2006-01-01

    We describe the development and first tests of ENOBIO, a dry electrode sensor concept for biopotential applications. In the proposed electrodes the tip of the electrode is covered with a forest of multi-walled carbon nanotubes (CNTs) that can be coated with Ag/AgCl to provide ionic-electronic transduction. The CNT brush-like structure is to penetrate the outer layers of the skin improving electrical contact as well as increase the contact surface area. In this paper we report the results of the first tests of this concept--immersion on saline solution and pig skin signal detection. These indicate performance on a par with state of the art research-oriented wet electrodes.

  19. Testing longwave radiation parameterizations under clear and overcast skies at Storglaciären, Sweden

    Directory of Open Access Journals (Sweden)

    J. Sedlar

    2009-04-01

    Full Text Available Energy balance based glacier melt models require accurate estimates of incoming longwave radiation but direct measurements are often not available. Multi-year near-surface meteorological data from Storglaciären, Northern Sweden, were used to evaluate commonly used longwave radiation parameterizations in a glacier environment under clear-sky and all-sky conditions. Parameterizations depending solely on air temperature performed worse than those which include water vapor pressure. All models tended to overestimate incoming longwave radiation during periods of low longwave radiation, while incoming longwave was underestimated when radiation was high. Under all-sky conditions root mean square error (RMSE and mean bias error (MBE were 17 to 20 W m−2 and −5 to 1 W m−2, respectively. Two attempts were made to circumvent the need of cloud cover data. First cloud fraction was parameterized as a function of the ratio, τ, of measured incoming shortwave radiation and calculated top of atmosphere radiation. Second, τ was related directly to the cloud factor (i.e. the increase in sky emissivity due to clouds. Despite large scatter between τ and both cloud fraction and the cloud factor, resulting calculations of hourly incoming longwave radiation for both approaches were only slightly more variable with RMSE roughly 3 W m−2 larger compared to using cloud observations as input. This is promising for longwave radiation modeling in areas where shortwave radiation data are available but cloud observations are not.

  20. Characterization and single cell testing of Pt/C electrodes prepared by electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Martin, A.J.; Chaparro, A.M.; Gallardo, B.; Folgado, M.A. [CIEMAT, Department of Energy, Avda. Complutense 22, 28040 Madrid (Spain); Daza, L. [CIEMAT, Department of Energy, Avda. Complutense 22, 28040 Madrid (Spain); Instituto de Catalisis y Petroleoquimica (CSIC), C/. Marie Curie 2, Campus Cantoblanco, 28049 Madrid (Spain)

    2009-07-01

    Electrodes for proton exchange membrane fuel cells (PEMFC) have been prepared by the electrodeposition method. For this task, the electrodeposition of platinum is carried out on a carbon black substrate impregnated with an ionomer, proton conducting, medium. Before electrodeposition, the substrate is submitted to an activation process to increase the hydrophilic character of the surface to a few microns depth. Electrodeposition of platinum takes place inside the generated surface hydrophilic layer, resulting in a continuous phase covering totally or partially carbon substrate grains. Cross sectional images show a decay profile of platinum towards the interior of the substrate, reflecting a deposition process limited by diffusion of PtCl{sub 6}{sup 2-} through the porous substrate. Electrodes with different platinum loads have been prepared, and membrane electrode assemblies (MEA) have been mounted with the electrodeposited electrodes as cathode and other standard components (commercial anode and Nafion{sup R} 117 membrane). The electrochemically active surface area determined from hydrogen underpotential deposition charge, is lower on the electrodeposited electrodes than on standard electrodes. However, single cell testing shows higher mass specific activity on electrodeposited cathodes with low and intermediate Pt load (below 0.05 mg Pt cm{sup -2}). (author)

  1. Characterization and single cell testing of Pt/C electrodes prepared by electrodeposition

    Science.gov (United States)

    Martín, A. J.; Chaparro, A. M.; Gallardo, B.; Folgado, M. A.; Daza, L.

    Electrodes for proton exchange membrane fuel cells (PEMFC) have been prepared by the electrodeposition method. For this task, the electrodeposition of platinum is carried out on a carbon black substrate impregnated with an ionomer, proton conducting, medium. Before electrodeposition, the substrate is submitted to an activation process to increase the hydrophilic character of the surface to a few microns depth. Electrodeposition of platinum takes place inside the generated surface hydrophilic layer, resulting in a continuous phase covering totally or partially carbon substrate grains. Cross sectional images show a decay profile of platinum towards the interior of the substrate, reflecting a deposition process limited by diffusion of PtCl 6 2- through the porous substrate. Electrodes with different platinum loads have been prepared, and membrane electrode assemblies (MEA) have been mounted with the electrodeposited electrodes as cathode and other standard components (commercial anode and Nafion R 117 membrane). The electrochemically active surface area determined from hydrogen underpotential deposition charge, is lower on the electrodeposited electrodes than on standard electrodes. However, single cell testing shows higher mass specific activity on electrodeposited cathodes with low and intermediate Pt load (below 0.05 mg Pt cm -2).

  2. Clear retainer

    Directory of Open Access Journals (Sweden)

    Priyakorn Chaimongkol

    2017-01-01

    Full Text Available A clear retainer is a removable retainer that is popular in the present day. Compared with conventional fixed and removable orthodontic retainers, it is a more esthetic, comfortable, and inexpensive appliance. Although several studies have been published about clear retainers, it could be difficult to interpret the results because of the variety of study designs, sample sizes, and research methods. This article is intended to compile the content from previous studies and discuss advantages, disadvantages, fabrication, insertion, and adjustment. Moreover, the effectiveness in maintaining dental position, occlusion, retention protocols, thickness, and survival rate of clear retainers is discussed.

  3. SNOW CLEARING

    CERN Multimedia

    Groupe de Transport/Transport Group

    1999-01-01

    In order to facilitate snow-clearing operations, which commence at 4.30 every morning, drivers of CERN vehicles are kindly requested to group their cars together in the car parks. This will greatly help us in our work. Thank you for your co-operation.Transport Group / ST-HMTel. 72202

  4. Development of Electrode Units for Electrokinetic Desalination of Masonry and Pilot Scale Test at Three locations for Removal of Chlorides

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Christensen, Iben Vernegren; Skibsted, Gry;

    2010-01-01

    Electrode units for electrokinetic desalination of masonry has been developed and tested in pilot scale at three different locations. The units are formed as casings with a metallic mesh electrode, and carbonate rich clay to buffer the acid produced at the anode. The case has an extra loose bottom...

  5. EQCM with air-gap excitation electrode. Calibration tests with copper and oxygen coatings

    Energy Technology Data Exchange (ETDEWEB)

    Bucur, R.V.; Mecea, V.M.; Carlsson, J.-O

    2003-10-15

    A holder for a quartz resonator with an adjustable air-gap excitation electrode (range: 0-300 {mu}m) is described, able to be used in an EQCM that is provided either with a metallic-film or a glued metallic-foil working electrode. An AT-cut plano-convex quartz crystal of 1.8 MHz and Pt-foil of 3 {mu}m thickness were used. Both the frequency shift and the quality factor of the quartz resonator were recorded during the calibration tests. Calibration data by electro-deposition of copper (in 0.1 M CuSO{sub 4}-solution) and oxygen (in both acid and basic solutions) on Pt-foil and Au-film electrodes, and at various air-gap widths, are presented. The frequency shifts for the Cu-calibration fit the Sauerbrey model at any air-gap width of the excitation electrode, while those for O-calibration fit only at relatively large values of the air-gap, >75 {mu}m. At small air-gap widths (<25 {mu}m), the O-calibration data deviate from the Sauerbrey model and yield an enhanced mass-sensitivity, up to 15 times higher. The different effects the air-gap width has on the response of the quartz resonator, as to the respective mass-variation of copper and oxygen layers deposited onto its surface, are ascribed to the difference in their features. Oxygen appears as a weakly bound, mono-atomic layer, while copper forms a rigid, strongly bound bulk layer.

  6. A blister-test apparatus for studies on the adhesion of materials used for neural electrodes.

    Science.gov (United States)

    Ordonez, Juan; Boehler, Christian; Schuettler, Martin; Stieglitz, Thomas

    2011-01-01

    A blister test apparatus has been developed, which allows a quantitative adhesion analysis of thin-film metallizations on polymers manufactured in cleanroom conditions suitable for micromachining of neural electrode arrays. The device is capable of pressurizing metallic membranes at wafer level, monitoring the pressure and the height of the developing blister while detecting the moment of delamination, allowing the calculation of the adhesion energy between metal film and polymer. The machine is designed for quantitative long-term studies of materials used in neural microelectrode arrays.

  7. Surface analysis of supercapacitor electrodes after long-lasting constant current tests

    Science.gov (United States)

    Jänes, Alar; Eskusson, Jaanus; Lust, Enn

    2013-12-01

    FIB-SEM, XPS, TOF-SIMS and electrochemical methods have been used for the characterisation of physical properties and chemical composition of microporous carbide derived carbon electrodes, prepared from TiC at 950 °C (noted as TiC-CDC) after 40000 charge/discharge cycles. Changes in surface chemical composition of TiC-CDC electrodes, includes partial contamination with reaction intermediates (F2, CHO-, CN-, organic radicals), and Al current collectors, like partial dissolution of Al from positively charged electrode and deposition of Al onto the negatively charged TiC-CDC electrode surface, have been analysed.

  8. Application of Automation Test Framework in Roaming Clearing System%自动化测试框架在漫游清算系统中的应用

    Institute of Scientific and Technical Information of China (English)

    何莹; 彭达

    2015-01-01

    为提高清算中心的测试效率,降低手工测试成本,通过对自动化测试技术进行研究,结合漫游清算系统业务流程,设计了一种自动化测试框架:DCHAutoTest。该框架基于Robot Framework,采用Python语言进行测试脚本开发,使用RIDE测试工具对测试脚本进行管理与调度,实现了测试执行、测试报告生成自动化,大大提高了测试效率。%In order to improve testing efficiency of clearing house and reduce cost of manual testing, automation testing technology was researched and an automation test framework DCHAutoTest was designed combined with business process of roaming clearing system. Based on Robot Framework, Python language was used in the framework to develop testing script, while RIDE was adopted to manage and schedule testing script. Thus, test implementation and test report were generated automatically to highly improve testing efifciency.

  9. Rapid Real-Time Antimicrobial Susceptibility Testing with Electrical Sensing on Plastic Microchips with Printed Electrodes.

    Science.gov (United States)

    Safavieh, Mohammadali; Pandya, Hardik J; Venkataraman, Maanasa; Thirumalaraju, Prudhvi; Kanakasabapathy, Manoj Kumar; Singh, Anupriya; Prabhakar, Devbalaji; Chug, Manjyot Kaur; Shafiee, Hadi

    2017-03-30

    Rapid antimicrobial susceptibility testing is important for efficient and timely therapeutic decision making. Due to globally spread bacterial resistance, the efficacy of antibiotics is increasingly being impeded. Conventional antibiotic tests rely on bacterial culture, which is time-consuming and can lead to potentially inappropriate antibiotic prescription and up-front broad range of antibiotic use. There is an urgent need to develop point-of-care platform technologies to rapidly detect pathogens, identify the right antibiotics, and monitor mutations to help adjust therapy. Here, we report a biosensor for rapid (microchips with printed electrodes using antibodies (30 min), and its electrical response is monitored in the presence and absence of antibiotics over an hour of incubation time. We evaluated the microchip with Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) as clinical models with ampicillin, ciprofloxacin, erythromycin, daptomycin, gentamicin, and methicillin antibiotics. The results are compared with the current standard methods, i.e. bacteria viability and conventional antibiogram assays. The technology presented here has the potential to provide precise and rapid bacteria screening and guidance in clinical therapies by identifying the correct antibiotics for pathogens.

  10. On the Application of Scanner in Clear Frequency Test on LTE%浅谈扫频仪在LTE清频测试中的运用

    Institute of Scientific and Technical Information of China (English)

    周浩然

    2013-01-01

      为了避免TD-LTE网络占用的各频段中存在其他网络制式信号占用和外部干扰,减轻后续网优工作的难度,应在未建站期间或建网初期展开清频测试,查找和定位干扰来源。通过分析扫频仪在清频中的优势,介绍了清频测试解决方案,并用测试项目案例加以分析说明。%In order to prevent the band used by TD-LTE network from being occupied by other network and disturbing by external interferences, and to reduce the difficulty of the subsequent network optimization, a clear frequency test should be taken before base station construction or in the early stage of network deployment to search and to locate interference sources. Analyzing the advantages of scanner in the clear frequency test, this paper proposes a clear frequency test solution and expounds on it according to a test project.

  11. Evaluation of tensile strength of tissue adhesives and sutures for clear corneal incisions using porcine and bovine eyes, with a novel standardized testing platform

    Directory of Open Access Journals (Sweden)

    Kaja S

    2012-02-01

    Full Text Available Simon Kaja, Daryl L Goad, Fatima Ali, Ashley Abraham, R Luke Rebenitsch, Savak Teymoorian, Rohit Krishna, Peter KoulenVision Research Center and Department of Ophthalmology, University of Missouri-Kansas City, School of Medicine, Kansas City, MO, USABackground: Tissue adhesives for ophthalmologic applications were proposed almost 50 years ago, yet to date no adequate tissue glues have been identified that combine strong sealing properties with adequate safety and absence of postsurgical side effects. In recent years, cataract surgeries and Descemet's stripping with endothelial keratoplasty procedures have significantly increased the number of clear corneal incisions performed. One of the obstacles to discovery and development of novel tissue adhesives has been the result of nonstandardized testing of potential tissue glues.Methods: We developed an instrument capable of controlling intraocular pressure in explanted porcine and bovine eyes in order to evaluate sealants, adhesives, and surgical closure methods used in ophthalmic surgery in a controlled, repeatable, and validated fashion. We herein developed and validated our instrument by testing the adhesive properties of cyanoacrylate glue in both porcine and bovine explant eyes.Results: The instrument applied and maintained intraocular pressure through a broad range of physiological intraocular pressures. Cyanoacrylate-based glues showed significantly enhanced sealing properties of clear corneal incisions compared with sutured wounds.Conclusion: This study shows the feasibility of our instrument for reliable and standardized testing of tissue adhesive for ophthalmological surgery.Keywords: manometer, intraocular pressure, applanation tonometry, clear corneal incision, tissue adhesive, ocular surgery

  12. A new disposable electrode for electrochemical study of leukemia K562 cells and anticancer drug sensitivity test.

    Science.gov (United States)

    Yu, Chunmei; Zhu, Zhenkun; Wang, Li; Wang, Qiuhong; Bao, Ning; Gu, Haiying

    2014-03-15

    Developing cost-effective and simple analysis tools is of vital importance for practical applications in bioanalysis. In this work, a new disposable electrochemical cell sensor with low cost and simple fabrication was proposed to study the electrochemical behavior of leukemia K562 cells and the effect of anticancer drugs on cell viability. The analytical device was integrated by using ITO glass as the substrate of working electrodes and paper as the electrolytic cell. The cyclic voltammetry of the K562 cells at the disposable electrode exhibited an irreversible anodic peak and the peak current is proportional to the cell number. This anodic peak is attributed to the oxidation of guanine in cells involving two protons per transfer of two electrons. For the drug sensitivity tests, arsenic trioxide and cyclophosphamide were added to cell culture media. As a result, the electrochemical responses of the K562 cells decreased significantly. The cytotoxicity curves and results obtained corresponded well with the results of CCK-8 assays. In comparison to conventional methods, the proposed method is simple, rapid and inexpensive. More importantly, the developed sensor is supposed to be a single-use disposable device and electrodes were prepared "as new" for each experiment. We think that such disposable electrodes with these characteristics are suitable for experimental study with cancer cells or other types of pathogens for disease diagnosis, drug selection and on-site monitoring.

  13. Detection and clearing of trapped ions in the high current Cornell photoinjector

    Science.gov (United States)

    Full, S.; Bartnik, A.; Bazarov, I. V.; Dobbins, J.; Dunham, B.; Hoffstaetter, G. H.

    2016-03-01

    We have recently performed experiments to test the effectiveness of three ion-clearing strategies in the Cornell high intensity photoinjector: DC clearing electrodes, bunch gaps, and beam shaking. The photoinjector reaches a new regime of linac beam parameters where high continuous wave beam currents lead to ion trapping. Therefore ion mitigation strategies must be evaluated for this machine and other similar future high current linacs. We have developed several techniques to directly measure the residual trapped ions. Our two primary indicators of successful clearing are the amount of ion current removed by a DC clearing electrode, and the absence of bremsstrahlung radiation generated by beam-ion interactions. Measurements were taken for an electron beam with an energy of 5 MeV and continuous wave beam currents in the range of 1-20 mA. Several theoretical models have been developed to explain our data. Using them, we are able to estimate the clearing electrode voltage required for maximum ion clearing, the creation and clearing rates of the ions while employing bunch gaps, and the sinusoidal shaking frequency necessary for clearing via beam shaking. In all cases, we achieve a maximum ion clearing of at least 70% or higher, and in some cases our data is consistent with full ion clearing.

  14. Review of progresses on clinical applications of ion selective electrodes for electrolytic ion tests: from conventional ISEs to graphene-based ISEs

    Directory of Open Access Journals (Sweden)

    Rongguo Yan

    2016-10-01

    Full Text Available There exist several positively and negatively charged electrolytes or ions in human blood, urine, and other body fluids. Tests that measure the concentration of these ions in clinics are performed using a more affordable, portable, and disposable potentiometric sensing method with few sample volumes, which requires the use of ion-selective electrodes (ISEs and reference electrodes. This review summarily descriptively presents progressive developments and applications of ion selective electrodes in medical laboratory electrolytic ion tests, from conventional ISEs, solid-contact ISEs, carbon nanotube based ISEs, to graphene-based ISEs.

  15. Clear correspondence between gated-diode R-G current and performance degradation of SOI n-MOSFETs after F-N stress tests

    Institute of Scientific and Technical Information of China (English)

    He Jin; Ma Chenyue; Wang Hao; Chen Xu; Zhang Chenfei; Lin Xinnan; Zhang Xing

    2009-01-01

    A clear correspondence between the gated-diode generation-recombination (R-G) current and the per-formance degradation of an SOI n-channel MOS transistor after F-N stress tests has been demonstrated. Due to the increase of interface traps after F-N stress tests, the R-G current of the gated-diode in the SOI-MOSFET architecture increases while the performance characteristics of the MOSFET transistor such as the saturation drain current and sub-threshold slope are degraded. From a series of experimental measurements of the gated-diode and SOI-MOSFET DC characteristics, a linear decrease of the drain saturation current and increase of the threshold volt-age as well as a like-line rise of the sub-threshold swing and a corresponding degradation in the trans-conductance are also observed. These results provide theoretical and experimental evidence for us to use the gated-diode tool to monitor SOI-MOSFET degradation.

  16. Review of progresses on clinical applications of ion selective electrodes for electrolytic ion tests: from conventional ISEs to graphene-based ISEs

    OpenAIRE

    Rongguo Yan; Shuai Qiu; Lei Tong; Yin Qian

    2016-01-01

    There exist several positively and negatively charged electrolytes or ions in human blood, urine, and other body fluids. Tests that measure the concentration of these ions in clinics are performed using a more affordable, portable, and disposable potentiometric sensing method with few sample volumes, which requires the use of ion-selective electrodes (ISEs) and reference electrodes. This review summarily descriptively presents progressive developments and applications of ion selective electro...

  17. Light stability tests of CH3NH3PbI3 perovskite solar cells using porous carbon counter electrodes.

    Science.gov (United States)

    Ito, Seigo; Mizuta, Gai; Kanaya, Shusaku; Kanda, Hiroyuki; Nishina, Tomoya; Nakashima, Seiji; Fujisawa, Hironori; Shimizu, Masaru; Haruyama, Yuichi; Nishino, Hitoshi

    2016-10-21

    The CH3NH3PbI3 perovskite solar cells have been fabricated using three-porous-layered electrodes as, 〈glass/F-doped tin oxide (FTO)/dense TiO2/porous TiO2-perovskite/porous ZrO2-perovskite/porous carbon-perovskite〉 for light stability tests. Without encapsulation in air, the CH3NH3PbI3 perovskite solar cells maintained 80% of photoenergy conversion efficiency from the initial value up to 100 h under light irradiation (AM 1.5, 100 mW cm(-2)). Considering the color variation of the CH3NH3PbI3 perovskite layer, the significant improvement of light stability is due to the moisture-blocking effect of the porous carbon back electrodes. The strong interaction between carbon and CH3NH3PbI3 perovskite was proposed by the measurements of X-ray photoelectron spectroscopy and X-ray diffraction of the porous carbon-perovskite layers.

  18. Standard test method for measurement of soil resistivity using the two-electrode soil box method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the equipment and a procedure for the measurement of soil resistivity, for samples removed from the ground, for use in the control of corrosion of buried structures. 1.2 Procedures allow for this test method to be used n the field or in the laboratory. 1.3 The test method procedures are for the resistivity measurement of soil samples in the saturated condition and in the as-received condition. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. Soil resistivity values are reported in ohm-centimeter. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.

  19. Inkjet printed multiwall carbon nanotube electrodes for dielectric elastomer actuators

    Science.gov (United States)

    Baechler, Curdin; Gardin, Samuele; Abuhimd, Hatem; Kovacs, Gabor

    2016-05-01

    Dielectric elastomers (DE’s) offer promising applications as soft and light-weight electromechanical actuators. It is known that beside the dielectric material, the electrode properties are of particular importance regarding the DE performance. Therefore, in recent years various studies have focused on the optimization of the electrode in terms of conductivity, stretchability and reliability. However, less attention was given to efficient electrode processing and deposition methods. In the present study, digital inkjet printing was used to deposit highly conductive and stretchable electrodes on silicone. Inkjet printing is a versatile and cost effective deposition method, which allows depositing complex-shaped electrode patterns with high precision. The electrodes were printed using an ink based on industrial low-cost MWCNT. Experiments have shown that the strain-conductivity properties of the printed electrode are strongly depended on the deposition parameters like drop-spacing and substrate temperature. After the optimization of the printing parameters, thin film electrodes could be deposited showing conductivities of up to 30 S cm-1 without the need of any post-treatment. In addition, electromechanical tests with fabricated DE actuators have revealed that the inkjet printed MWCNT electrodes are capable to self-clear in case of a dielectric breakdown.

  20. Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

    DEFF Research Database (Denmark)

    Wiberg, Gustav Karl Henrik; Fleige, Michael; Arenz, Matthias

    2015-01-01

    field are braced using a KF-25 vacuum flange clamp, which allows an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT...

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

    Science.gov (United States)

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

    1993-01-01

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

  2. Ion clearing in an ERL

    Science.gov (United States)

    Hoffstaetter, Georg H.; Liepe, Matthias

    2006-02-01

    The rest-gas in the beam-pipe of a particle accelerator is readily ionized by effects like collisions, synchrotron radiation and field emission. Positive ions are attracted to electron beams and create a nonlinear potential in the vicinity of the beam which can lead to beam halo, particle loss, optical errors or transverse and longitudinal instabilities. In an energy recovery linac (ERL) where beam-loss has to be minimal, and where beam positions and emittances have to be very stable in time, these ion effects have to be avoided. Here we investigate three measures of avoiding ion accumulation: (a) A long gap between linac bunch trains that allows ions to drift out of the beam region, a measure regularly applied in linacs; (b) a short ion clearing gap in the beam that leads to a time varying beam potential and produces large excited oscillations of ions around the electron beam, a measure regularly applied in storage rings; (c) Clearing electrodes that create a sufficient voltage to draw ions out of the beam potential, a measure used for DC electron beams and for antiproton beams. For the parameters of the X-ray ERL planned at Cornell University we show that method (a) cannot be applied, method (b) is technically cumbersome, and (c) should be most easily applicable.

  3. Clear cell chondrosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R.; David, R.; Cierney, G. III

    1985-01-01

    The clinical, radiologic, and histopathologic features of three cases of clear cell chondrosarcoma are described. On radiographs, this rather benign-appearing tumor resembles a chondroblastoma when it occurs at the end of a long bone, and may occasionally show a calcified matrix. However, it has distinctive tumor cells with a centrally placed vesicular nucleus surrounded by clear cytoplasm. The lesion has a low-grade malignancy and is amenable to en bloc surgical resection, which results in a much better prognosis than that of conventional chondrosarcoma.

  4. Anodic stripping voltammetry of gold nanoparticles at boron-doped diamond electrodes and its application in immunochromatographic strip tests.

    Science.gov (United States)

    Ivandini, Tribidasari A; Wicaksono, Wiyogo P; Saepudin, Endang; Rismetov, Bakhadir; Einaga, Yasuaki

    2015-03-01

    Anodic stripping voltammetry (ASV) of colloidal gold-nanoparticles (AuNPs) was investigated at boron-doped diamond (BDD) electrodes in 50 mM HClO4. A deposition time of 300 s at-0.2 V (vs. Ag/AgCl) was fixed as the condition for the ASV. The voltammograms showed oxidation peaks that could be attributed to the oxidation of gold. These oxidation peaks were then investigated for potential application in immunochromatographic strip tests for the selective and quantitative detection of melamine, in which AuNPs were used as the label for the antibody of melamine. Linear regression of the oxidation peak currents appeared in the concentration range from 0.05-0.6 μg/mL melamine standard, with an estimated LOD of 0.069 μg/mL and an average relative standard deviation of 8.0%. This indicated that the method could be considered as an alternative method for selective and quantitative immunochromatographic applications. The validity was examined by the measurements of melamine injected into milk samples, which showed good recovery percentages during the measurements.

  5. Hierarchical sulfur electrodes as a testing platform for understanding the high-loading capability of Li-S batteries

    Science.gov (United States)

    Chung, Sheng-Heng; Chang, Chi-Hao; Manthiram, Arumugam

    2016-12-01

    Lithium-sulfur (Li-S) batteries are considered as an attractive electrochemical energy storage system due to the high theoretical capacity of sulfur (1,675 mA h g-1). However, high-loading sulfur cathodes would need to be employed for the Li-S cells to be practical, but the resulting poor cell cyclability and severe electrode degradation hamper their development. Here, we present a hierarchical sulfur cathode as a testing platform for understanding the high-loading capability of Li-S batteries. The hierarchical cathode presents good electrochemical utilization of above 70%, stable cyclability for 500-1,000 cycles, and high sulfur loadings of 4.2-10.0 mg cm-2. The exploration of the activation and the polysulfide-retention processes of the high-loading cathodes illustrates that the electrochemical stability mainly results from the stabilization of dissolved polysulfides within the cathode region as the electrochemically active catholyte. Therefore, the utilization of stabilized polysulfide migration might be a meaningful opportunity for designing high-loading cathodes and further improving their electrochemical stability and long-term cyclability.

  6. Snow-clearing operations

    CERN Document Server

    EN Department

    2010-01-01

    To facilitate snow clearing operations, which commence at 4.30 in the morning, all drivers of CERN cars are kindly requested to park them together in groups. This will help us greatly assist us in our work. Thank-you for your help. Transport Group / EN-HE Tel. 72202

  7. Magnetohydrodynamic electrode

    Science.gov (United States)

    Boquist, Carl W.; Marchant, David D.

    1978-01-01

    A ceramic-metal composite suitable for use in a high-temperature environment consists of a refractory ceramic matrix containing 10 to 50 volume percent of a continuous high-temperature metal reinforcement. In a specific application of the composite, as an electrode in a magnetohydrodynamic generator, the one surface of the electrode which contacts the MHD fluid may have a layer of varying thickness of nonreinforced refractory ceramic for electrode temperature control. The side walls of the electrode may be coated with a refractory ceramic insulator. Also described is an electrode-insulator system for a MHD channel.

  8. Electroanalysis with carbon paste electrodes

    CERN Document Server

    Svancara, Ivan; Walcarius, Alain; Vytras, Karel

    2011-01-01

    Introduction to Electrochemistry and Electroanalysis with Carbon Paste-Based ElectrodesHistorical Survey and GlossaryField in Publication Activities and LiteratureCarbon Pastes and Carbon Paste ElectrodesCarbon Paste as the Binary MixtureClassification of Carbon Pastes and Carbon Paste ElectrodesConstruction of Carbon Paste HoldersCarbon Paste as the Electrode MaterialPhysicochemical Properties of Carbon PastesElectrochemical Characteristics of Carbon PastesTesting of Unmodified CPEsIntera

  9. Characterization of micro-contact resistance between a gold nanocrystalline line and a tungsten electrode probe in interconnect fatigue testing.

    Science.gov (United States)

    Ling, Xue; Wang, Yusheng; Li, Xide

    2014-10-01

    An electromechanically-coupled micro-contact resistance measurement system is built to mimic the contact process during fatigue testing of nanoscale-thickness interconnects using multiple probe methods. The design combines an optical microscope, high-resolution electronic balance, and micromanipulator-controlled electric probe, and is coupled with electrical measurements to investigate microscale contact physics. Experimental measurements are performed to characterize the contact resistance response of the gold nanocrystalline pad of a 35-nm-thick interconnect under mechanical force applied by a tungsten electrode probe. Location of a stable region for the contact resistance and the critical contact force provides better understanding of micro-contact behavior relative to the effects of the contact force and the nature of the contact surface. Increasing contact temperature leads to reduced contact resistance, softens the pad material, and modifies the contact surface. The stability of both contact resistance and interconnect resistance is studied under increasing contact force. Major fluctuations emerge when the contact force is less than the critical contact force, which shows that temporal contact resistance will affect interconnect resistance measurement accuracy, even when using the four-wire method. This performance is demonstrated experimentally by heating the Au line locally with a laser beam. Finally, the contact resistances are calculated using the LET (Li-Etsion-Talke) model together with combined Holm and Sharvin theory under various contact forces. Good agreement between the results is obtained. This research provides a way to measure change in interconnect line resistance directly under a stable contact resistance regime with a two-wire method that will greatly reduce the experimental costs.

  10. Clearing the Big Smog

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Beijing is trying to clean up its sky with a new standard for vehicle emissions From March 1,Beijing has imple- mented a new stricter vehicle emission standard that could lead to cleaner air,but also force thousands of cars off the road. StandardⅣ,the latest in a series of measures aimed at clearing the per- sistent smog,will match the current standard of the European Union. All the new light petro vehicles that are on sale in the Beijing market shall

  11. Consciousness CLEARS the mind.

    Science.gov (United States)

    Grossberg, Stephen

    2007-11-01

    A full understanding of consciousness requires that we identify the brain processes from which conscious experiences emerge. What are these processes, and what is their utility in supporting successful adaptive behaviors? Adaptive Resonance Theory (ART) predicted a functional link between processes of Consciousness, Learning, Expectation, Attention, Resonance and Synchrony (CLEARS), including the prediction that "all conscious states are resonant states". This connection clarifies how brain dynamics enable a behaving individual to autonomously adapt in real time to a rapidly changing world. The present article reviews theoretical considerations that predicted these functional links, how they work, and some of the rapidly growing body of behavioral and brain data that have provided support for these predictions. The article also summarizes ART models that predict functional roles for identified cells in laminar thalamocortical circuits, including the six layered neocortical circuits and their interactions with specific primary and higher-order specific thalamic nuclei and nonspecific nuclei. These predictions include explanations of how slow perceptual learning can occur without conscious awareness, and why oscillation frequencies in the lower layers of neocortex are sometimes slower beta oscillations, rather than the higher-frequency gamma oscillations that occur more frequently in superficial cortical layers. ART traces these properties to the existence of intracortical feedback loops, and to reset mechanisms whereby thalamocortical mismatches use circuits such as the one from specific thalamic nuclei to nonspecific thalamic nuclei and then to layer 4 of neocortical areas via layers 1-to-5-to-6-to-4.

  12. Evaluation of threshold response and appropriate electrode placement site for electric pulp testing in fluorosed anterior teeth: An in vivo study

    Science.gov (United States)

    Vemisetty, Harikumar; Vanapatla, Amulya; Ravichandra, Polavarapu Venkata; Reddy, Surakanti Jayaprada; Punna, Rajani; Chandragiri, Srujana

    2016-01-01

    Background: Accurate diagnosis is key to success. Diagnosing the pulpal status in varied clinical situations poses a challenge to the clinician. Electric pulp test (EPT) is one of the valuable attempts in evaluating the sensibility of pulp tissue. The aim of this study was to find out and compare the threshold levels and optimal electrode placement site for EPT in fluorosed and nonfluorosed anterior teeth. Materials and Methodology: Eighty volunteers recruited for this study were divided into two groups based on the incidence of dental fluorosis. Electric pulp testing was done on either of the central incisors in fluorosed and nonfluorosed group. Four sites on each crown were tested 4 times with digitest electric pulp tester, and the mean of the threshold responses was recorded. The data were analyzed with SPSS, version 11. Means of variables from each location were compared using one-way ANOVA and Tukey's post-hoc test while the critical level of significance was set at P 0.05). Conclusion: Within the limitations of this study, it can be concluded that fluorosed teeth respond to higher threshold levels than the non-fluorosed teeth, and incisal edge was the optimal electrode placement site. PMID:27274345

  13. Microvoltammetric Electrodes.

    Science.gov (United States)

    1985-09-25

    Microvoltammetric Electrodes, J. 0. Howell, R. M. Wightman, Anal. Chem., 56, 524-529 (1984). 2. Flow Rate Independent Amperometric Cell , W. L. Caudill...Electroanal. Chem., 182, 113-122 (1985). C. List of all publications 1. Flow Rate Independent Amperometric Cell , W. L. Caudill, J. 0. Howell, R. M

  14. Large-sized out-of-plane stretchable electrodes based on poly-dimethylsiloxane substrate

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Namsun [School of Mechatronics, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Lee, Jongho [School of Mechatronics, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Research Institute for Solar and Sustainable Energies (RISE), Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Kim, Sohee, E-mail: soheekim@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of); Department of Medical System Engineering (DMSE), Gwangju Institute of Science and Technology (GIST), Gwangju 500-712 (Korea, Republic of)

    2014-12-15

    This paper describes a reliable fabrication method of stretchable electrodes based on poly-dimethylsiloxane (PDMS) substrate. The electrode traces and pads were formed in out-of-plane structures to improve the flexibility and stretchability of the electrode array. The suspended traces and pads were attached to the PDMS substrate via parylene posts that were located nearby the traces and under the pads. As only conventional micro-electro-mechanical systems techniques were used, the out-of-plane electrode arrays were clearly fabricated at wafer level with high yield and reliability. Also, bi-layer out-of-plane electrodes were formed through additional fabrication steps in addition to mono-layer out-of-plane electrodes. The mechanical characteristics such as the stretchability, flexibility, and foldability of the fabricated electrodes were evaluated, resulting in stable electrical connection of the metal traces with up to 32.4% strain and up to 360° twist angle over 25 mm. The durability in stretched condition was validated by cyclic stretch test with 10% and 20% strain, resulting in electrical disconnection at 8600 cycles when subjected to 20% strain. From these results, it is concluded that the proposed fabrication method produced highly reliable, out-of-plane and stretchable electrodes, which would be used in various flexible and stretchable electronics applications.

  15. Macro and microscale mechanical testing and local electrode atom probe measurements of STIP irradiated F82H, Fe-8Cr ODS and Fe-8Cr-2W ODS

    Energy Technology Data Exchange (ETDEWEB)

    Hosemann, P., E-mail: peterh@lanl.gov [Los Alamos National Laboratory (LANL), MST-8 (United States); University of California Berkeley, Department of Nuclear Engineering (United States); Stergar, E. [University of California Berkeley, Department of Nuclear Engineering (United States); Peng, L. [Paul Scherrer Institute (PSI), 5332 Villigen PSI (Switzerland); Institute of Plasma Physics, Chinese Academy of Science (China); Dai, Y. [Paul Scherrer Institute (PSI), 5332 Villigen PSI (Switzerland); Maloy, S.A. [Los Alamos National Laboratory (LANL), MST-8 (United States); Pouchon, M.A. [Paul Scherrer Institute (PSI), 5332 Villigen PSI (Switzerland); Shiba, K.; Hamaguchi, D. [Japan Atomic Energy Agency (JAEA) (Japan); Leitner, H. [MontanuniversitaetLeoben, Department fuerMetallkunde (Austria)

    2011-10-01

    The reduced activation ferritic/martensitic alloy F82H (Fe-8Cr-2W-0.2V-0.04Ta-0.1C) is being considered as a structural material for several different fusion related nuclear applications. The oxide dispersion strengthened (ODS) alloys Fe-8Cr-2W ODS and Fe-8Cr ODS were developed for better high-temperature strength and radiation tolerance. These materials have been exposed to a neutron and proton environment in the Spallation Target Irradiation Program (STIP) (<13 dpa) with an average He/dpa ratio of 60 appm He/dpa at irradiation temperatures 159-347 deg. C. After irradiation, the samples were tensile tested at different temperatures. The post tensile testing fractured parts were collected and nanoindentation, microcompression testing and local electrode atom probe was conducted. The information gained by local electron atom probe in combination with the micro, nano and macroscopic mechanical tests allows one to establish a fundamental understanding of the relationship between the data measured at different scales on irradiated materials.

  16. Macro and microscale mechanical testing and local electrode atom probe measurements of STIP irradiated F82H, Fe-8Cr ODS and Fe-8Cr-2W ODS

    Science.gov (United States)

    Hosemann, P.; Stergar, E.; Peng, L.; Dai, Y.; Maloy, S. A.; Pouchon, M. A.; Shiba, K.; Hamaguchi, D.; Leitner, H.

    2011-10-01

    The reduced activation ferritic/martensitic alloy F82H (Fe-8Cr-2W-0.2V-0.04Ta-0.1C) is being considered as a structural material for several different fusion related nuclear applications. The oxide dispersion strengthened (ODS) alloys Fe-8Cr-2W ODS and Fe-8Cr ODS were developed for better high-temperature strength and radiation tolerance. These materials have been exposed to a neutron and proton environment in the Spallation Target Irradiation Program (STIP) (<13 dpa) with an average He/dpa ratio of 60 appm He/dpa at irradiation temperatures 159-347 °C. After irradiation, the samples were tensile tested at different temperatures. The post tensile testing fractured parts were collected and nanoindentation, microcompression testing and local electrode atom probe was conducted. The information gained by local electron atom probe in combination with the micro, nano and macroscopic mechanical tests allows one to establish a fundamental understanding of the relationship between the data measured at different scales on irradiated materials.

  17. Media Language, Clear or Obscure

    DEFF Research Database (Denmark)

    Jakobsen, Bjarne le Fevre; Ejstrup, Michael

    2015-01-01

    Abstract— Be clear, not obscure. One of the four maxims for optimal communication is that it is essential to develop proficiency in being concise and clear. The question is whether this is really a good idea in all contexts. There is some evidence to the contrary. Undoubtedly, we have many contex...... for the survival of free speech....... growth in diversity, means that media need to be very cognizant of the stringency with which they handle the advice to be linguistically clear and concise. The need to pay great attention to situational awareness is highly visible and intrusive. Attention to situational awareness seems to be crucial...

  18. Background reduction of the KATRIN spectrometers. Transmission function of the pre-spectrometer and systematic tests of the main-spectrometer wire electrode

    Energy Technology Data Exchange (ETDEWEB)

    Prall, Matthias

    2011-07-04

    precision). These measurements, together with the results of various quality assurance tests are stored in a database allowing to reconstruct the properties and history of each single electrode module. The UHV-compatible, fail-save, non-magnetic high voltage distribution, routing 46 voltages to the electrode modules inside the MS, was designed, tested systematically and its installation was started. The pre-spectrometer (PS), which has the same working principle as the MS is placed in front of it in the KATRIN experiment. It is foreseen to operate the MS at a potential of about 18.57 keV and the PS at about 18.3 keV reducing the rate of {beta}-decay electrons entering the MS to about 10{sup 3} s{sup -1}. This measure reduces the electron scattering probability in the MS and thus the background rate. Like this, however, electrons are confined longitudinally between the spectrometer potentials and radially by the strong magnetic field of a solenoid, placed between them. The electrons trapped in this Penning trap can also produce background. This work investigates the possibility to diminish this background source by reducing the PS potential by several keV worsening the trapping conditions. In this configuration, however, the PS transmission probability could be reduced as an adiabaticity requirement guaranteeing that electrons follow the magnetic field lines through the PS and are transmitted, is potentially violated. This phenomenon would introduce an additional systematic uncertainty for KATRIN. Therefore, the pre-spectrometer transmission at several magnetic fields settings. These investigations show that there are no non-adiabatic transmission losses for magnetic fields larger, or equal to 2.25 T (50% KATRIN design value).

  19. Optical clearing at cellular level

    Science.gov (United States)

    Kinnunen, Matti; Bykov, Alexander V.; Tuorila, Juho; Haapalainen, Tomi; Karmenyan, Artashes V.; Tuchin, Valery V.

    2014-07-01

    Strong light scattering in tissues and blood reduces the usability of many optical techniques. By reducing scattering, optical clearing enables deeper light penetration and improves resolution in several optical imaging applications. We demonstrate the usage of optical tweezers and elastic light scattering to study optical clearing [one of the major mechanisms-matching of refractive indices (RIs)] at the single particle and cell level. We used polystyrene spheres and human red blood cells (RBCs) as samples and glycerol or glucose water solutions as clearing agents. Optical tweezers kept single microspheres and RBCs in place during the measurement of light scattering patterns. The results show that optical clearing reduces the scattering cross section and increases g. Glucose also decreased light scattering from a RBC. Optical clearing affected the anisotropy factor g of 23.25-μm polystyrene spheres, increasing it by 0.5% for an RI change of 2.2% (20% glycerol) and 0.3% for an RI change of 1.1% (13% glucose).

  20. Defibrillation overload recovery performance test system for ECG electrode%心电电极除颤过载恢复性能测试系统

    Institute of Scientific and Technical Information of China (English)

    罗兰英; 田学隆; 周平; 李一言

    2011-01-01

    除颤过载恢复是心电电极的重要电性能,它的优劣直接影响到除颤后心电波形的检测和显示,进而影响对患者的抢救和治疗进程.文中开发了一种心电电极除颤过载性能测试系统,根据最新医药行业标准,基于C8051 F340的硬件系统,通过USB协议进行数据传输,在LabVIEW的软件平台上,实现了对除颤恢复性能指标的检测(包括交流阻抗的测试).系统采用良好的电隔离控制和检测,能精确控制测试过程中的充放电时间.实验结果表明,该系统能准确有效的测试电极对的除颤过载恢复性能,并具有安全、准确、操作简单等优点.%Defibrillation overload recovery performance is one of the most important electrical properties of ECG electrodes, which directly affects the ECG display after the patient is defibrillated, thereby affects the diagnosis and treatment of the patient. A defibrillation overload recovery performance test system for ECG electrodes was developed according to the latest pharmaceutical industry standards and based on the C8051F340 hardware system. With USB protocol data transfer, the detection of defibrillation overload recovery performance parameters (including AC impedance) is implemented on Lab VIEW software platform. The system has good electrical isolation control, which can accurately operate the charging and discharging time during test process automatically. Experiment result shows that this system has good performance, and features safe, accurate and easy to operate.

  1. Advantage of four-electrode over two-electrode defibrillators

    Science.gov (United States)

    Bragard, J.; Šimić, A.; Laroze, D.; Elorza, J.

    2015-12-01

    Defibrillation is the standard clinical treatment used to stop ventricular fibrillation. An electrical device delivers a controlled amount of electrical energy via a pair of electrodes in order to reestablish a normal heart rate. We propose a technique that is a combination of biphasic shocks applied with a four-electrode system rather than the standard two-electrode system. We use a numerical model of a one-dimensional ring of cardiac tissue in order to test and evaluate the benefit of this technique. We compare three different shock protocols, namely a monophasic and two types of biphasic shocks. The results obtained by using a four-electrode system are compared quantitatively with those obtained with the standard two-electrode system. We find that a huge reduction in defibrillation threshold is achieved with the four-electrode system. For the most efficient protocol (asymmetric biphasic), we obtain a reduction in excess of 80% in the energy required for a defibrillation success rate of 90%. The mechanisms of successful defibrillation are also analyzed. This reveals that the advantage of asymmetric biphasic shocks with four electrodes lies in the duration of the cathodal and anodal phase of the shock.

  2. Powder processing of hybrid titanium neural electrodes

    Science.gov (United States)

    Lopez, Jose Luis, Jr.

    A preliminary investigation into the powder production of a novel hybrid titanium neural electrode for EEG is presented. The rheological behavior of titanium powder suspensions using sodium alginate as a dispersant are examined for optimal slip casting conditions. Electrodes were slip cast and sintered at 950°C for 1 hr, 1000°C for 1, 3, and 6 hrs, and 1050°C for 1 hr. Residual porosities from sintering are characterized using Archimedes' technique and image analysis. The pore network is gel impregnated by submerging the electrodes in electrically conductive gel and placing them in a chamber under vacuum. Gel evaporation of the impregnated electrodes is examined. Electrodes are characterized in the dry and gelled states using impedance spectrometry and compared to a standard silver- silver chloride electrode. Power spectral densities for the sensors in the dry and gelled state are also compared. Residual porosities for the sintered specimens were between 50.59% and 44.81%. Gel evaporation tests show most of the impregnated gel evaporating within 20 min of exposure to atmospheric conditions with prolonged evaporation times for electrodes with higher impregnated gel mass. Impedance measurements of the produced electrodes indicate the low impedance of the hybrid electrodes are due to the increased contact area of the porous electrode. Power spectral densities of the titanium electrode behave similar to a standard silver-silver chloride electrode. Tests suggest the powder processed hybrid titanium electrode's performance is better than current dry contact electrodes and comparable to standard gelled silver-silver chloride electrodes.

  3. The art of thinking clearly

    CERN Document Server

    Dobelli, Rolf

    2013-01-01

    The Art of Thinking Clearly by world-class thinker and entrepreneur Rolf Dobelli is an eye-opening look at human psychology and reasoning — essential reading for anyone who wants to avoid “cognitive errors” and make better choices in all aspects of their lives. Have you ever: Invested time in something that, with hindsight, just wasn’t worth it? Or continued doing something you knew was bad for you? These are examples of cognitive biases, simple errors we all make in our day-to-day thinking. But by knowing what they are and how to spot them, we can avoid them and make better decisions. Simple, clear, and always surprising, this indispensable book will change the way you think and transform your decision-making—work, at home, every day. It reveals, in 99 short chapters, the most common errors of judgment, and how to avoid them.

  4. Writing clear animal activity proposals.

    Science.gov (United States)

    Pinson, David M

    2011-06-01

    Although IACUC-related topics are frequently discussed in the literature, there is little published information about how to write animal activity proposals. In this article, the author discusses key considerations in the writing and review of animal activity proposals. The author then describes a framework for developing and writing clear animal activity proposals that highlight animal welfare concerns. Though these recommendations are aimed at individuals writing and reviewing research proposals, the framework can be modified for other types of animal activity proposals.

  5. Cobalt Phthalocyanine Modified Electrodes Utilised in Electroanalysis: Nano-Structured Modified Electrodes vs. Bulk Modified Screen-Printed Electrodes

    Directory of Open Access Journals (Sweden)

    Christopher W. Foster

    2014-11-01

    Full Text Available Cobalt phthalocyanine (CoPC compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated within the ink of a screen-printed sensor, providing a one-shot economical and disposable electrode configuration. In this paper we critically compare CoPC modified electrodes prepared by drop casting CoPC nanoparticles (nano-CoPC onto a range of carbon based electrode substrates with that of CoPC bulk modified screen-printed electrodes in the sensing of the model analytes L-ascorbic acid, oxygen and hydrazine. It is found that no “electrocatalysis” is observed towards L-ascorbic acid using either of these CoPC modified electrode configurations and that the bare underlying carbon electrode is the origin of the obtained voltammetric signal, which gives rise to useful electroanalytical signatures, providing new insights into literature reports where “electrocatalysis” has been reported with no clear control experiments undertaken. On the other hand true electrocatalysis is observed towards hydrazine, where no such voltammetric features are witnessed on the bare underlying electrode substrate.

  6. Cobalt phthalocyanine modified electrodes utilised in electroanalysis: nano-structured modified electrodes vs. bulk modified screen-printed electrodes.

    Science.gov (United States)

    Foster, Christopher W; Pillay, Jeseelan; Metters, Jonathan P; Banks, Craig E

    2014-11-19

    Cobalt phthalocyanine (CoPC) compounds have been reported to provide electrocatalytic performances towards a substantial number of analytes. In these configurations, electrodes are typically constructed via drop casting the CoPC onto a supporting electrode substrate, while in other cases the CoPC complex is incorporated within the ink of a screen-printed sensor, providing a one-shot economical and disposable electrode configuration. In this paper we critically compare CoPC modified electrodes prepared by drop casting CoPC nanoparticles (nano-CoPC) onto a range of carbon based electrode substrates with that of CoPC bulk modified screen-printed electrodes in the sensing of the model analytes L-ascorbic acid, oxygen and hydrazine. It is found that no "electrocatalysis" is observed towards L-ascorbic acid using either of these CoPC modified electrode configurations and that the bare underlying carbon electrode is the origin of the obtained voltammetric signal, which gives rise to useful electroanalytical signatures, providing new insights into literature reports where "electrocatalysis" has been reported with no clear control experiments undertaken. On the other hand true electrocatalysis is observed towards hydrazine, where no such voltammetric features are witnessed on the bare underlying electrode substrate.

  7. Evaluation of threshold response and appropriate electrode placement site for electric pulp testing in fluorosed anterior teeth: An in vivo study

    Directory of Open Access Journals (Sweden)

    Harikumar Vemisetty

    2016-01-01

    Conclusion: Within the limitations of this study, it can be concluded that fluorosed teeth respond to higher threshold levels than the non-fluorosed teeth, and incisal edge was the optimal electrode placement site.

  8. A dry electrode for EEG recording.

    Science.gov (United States)

    Taheri, B A; Knight, R T; Smith, R L

    1994-05-01

    This paper describes the design, fabrication and testing of a prototype dry surface electrode for EEG signal recording. The new dry electrode has the advantages of no need for skin preparation or conductive paste, potential for reduced sensitivity to motion artifacts and an enhanced signal-to-noise ratio. The electrode's sensing element is a 3 mm stainless steel disk which has a 2000 A (200 nm) thick nitride coating deposited onto one side. The back side of the disk is attached to an impedance converting amplifier. The prototype electrode was mounted on a copper plate attached to the scalp by a Velcro strap. The performance of this prototype dry electrode was compared to commercially available wet electrodes in 3 areas of electroencephalogram (EEG) recording: (1) spontaneous EEG, (2) sensory evoked potentials, and (3) cognitive evoked potentials. In addition to the raw EEG, the power spectra of the signals from both types of electrodes were also recorded. The results suggest that the dry electrode performs comparably to conventional electrodes for all types of EEG signal analysis. This new electrode may be useful for the production of high resolution surface maps of brain activity where a large number of electrodes or prolonged recording times are required.

  9. Microphonics in biopotential measurements with capacitive electrodes.

    Science.gov (United States)

    Luna-Lozano, Pablo S; Pallas-Areny, Ramon

    2010-01-01

    Biopotential measurements with capacitive electrodes do not need any direct contact between electrode and skin, which saves the time devoted to expose and prepare the contact area when measuring with conductive electrodes. However, mechanical vibrations resulting from physiological functions such as respiration and cardiac contraction can change the capacitance of the electrode and affect the recordings. This transformation of mechanical vibrations into undesired electric signals is termed microphonics. We have evaluated microphonics in capacitive ECG recordings obtained from a dressed subject seated on a common chair with electrodes placed on the front side of the backrest of the chair. Depending on the softness of the backrest, the recordings may be clearly affected by the displacement of the thorax back wall due to the respiration and to the heart's mechanical activity.

  10. Effect of electrode shape on grounding resistances - Part 1

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Dahlin, Torleif

    2016-01-01

    . The focus-one protocol is a new method for estimating single electrode grounding resistances by measuring the resistance between a single electrode in an ERT array and all the remaining electrodes connected in parallel. For large arrays, the measured resistance is dominated by the grounding resistance...... of the electrode under test, the focus electrode. We have developed an equivalent circuit model formulation for the resistance measured when applying the focus-one protocol. Our model depends on the individual grounding resistances of the electrodes of the array, the mutual resistances between electrodes......, and the instrument input impedance. Using analytical formulations for the potentials around prolate and oblate spheroidal electrode models (as approximations for rod and plate electrodes), we have investigated the performance and accuracy of the focus-one protocol in estimating single-electrode grounding resistances...

  11. Long Life Nickel Electrodes for Nickel-Hydrogen Cells: Fiber Substrates Nickel Electrodes

    Science.gov (United States)

    Rogers, Howard H.

    2000-01-01

    Samples of nickel fiber mat electrodes were investigated over a wide range of fiber diameters, electrode thickness, porosity and active material loading levels. Thickness' were 0.040, 0.060 and 0.080 inches for the plaque: fiber diameters were primarily 2, 4, and 8 micron and porosity was 85, 90, and 95%. Capacities of 3.5 in. diameter electrodes were determined in the flooded condition with both 26 and 31% potassium hydroxide solution. These capacity tests indicated that the highest capacities per unit weight were obtained at the 90% porosity level with a 4 micron diameter fiber plaque. It appeared that the thinner electrodes had somewhat better performance, consistent with sintered electrode history. Limited testing with two-positive-electrode boiler plate cells was also carried out. Considerable difficulty with constructing the cells was encountered with short circuits the major problem. Nevertheless, four cells were tested. The cell with 95% porosity electrodes failed during conditioning cycling due to high voltage during charge. Discharge showed that this cell had lost nearly all of its capacity. The other three cells after 20 conditioning cycles showed capacities consistent with the flooded capacities of the electrodes. Positive electrodes made from fiber substrates may well show a weight advantage of standard sintered electrodes, but need considerably more work to prove this statement. A major problem to be investigated is the lower strength of the substrate compared to standard sintered electrodes. Problems with welding of leads were significant and implications that the electrodes would expand more than sintered electrodes need to be investigated. Loading levels were lower than had been expected based on sintered electrode experiences and the lower loading led to lower capacity values. However, lower loading causes less expansion and contraction during cycling so that stress on the substrate is reduced.

  12. A method to locate electrode placement.

    Science.gov (United States)

    Brodnick, D

    2000-01-01

    A new method uses redundancy in the 12-lead electrocardiogram (ECG) to determine the angles to all of the electrodes used to record the ECG. No other transducers or signals are needed. The method, a matrix manipulation of the standard 12-lead, would be applicable to all existing ECGs already stored on hospital systems. The invention of this method was originally motivated by the slight differences seen between ECGs acquired by the standard resting electrode placement versus those acquired in a monitoring or exercise placement. An ECG signal is acquired in multiple channels. A covariance matrix is formed. From the eigenvector solution of the matrix, the angles between the eigenvectors and the original signal vectors are determined. The angles calculated for any ECG test are compared to reference angles to determine whether the electrodes are placed in the standard ECG electrode placement, an alternative electrode placement, or an incorrect electrode placement.

  13. An apparatus for studying electrical breakdown in liquid helium at 0.4 K and testing electrode materials for the SNS nEDM experiment

    CERN Document Server

    Ito, T M; Yao, W; Beck, D H; Cianciolo, V; Clayton, S M; Crawford, C; Currie, S A; Filippone, B W; Griffith, W C; Makela, M; Schmid, R; Seidel, G M; Tang, Z; Wagner, D; Wei, W; Williamson, S E

    2015-01-01

    We have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and $\\sim$600 torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of $1-2$ cm between them, and a potential up to $\\pm 50$ kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a wide range of pressures at 0.4 K. We also measured the current between two electrodes. Our initial results, $I 5\\times10^{18}$ $\\Omega\\cdot$cm. This lower bound is 5 times larger than the bound previously measured. We report the design, construction, and operational experience of the apparatus, as well as initial results.

  14. Electrostatic atomization: Effect of electrode materials on electrostatic atomizer performance

    Science.gov (United States)

    Sankaran, Abhilash; Staszel, Christopher; Kashir, Babak; Perri, Anthony; Mashayek, Farzad; Yarin, Alexander

    2016-11-01

    Electrostatic atomization was studied experimentally with a pointed electrode in a converging nozzle. Experiments were carried out on poorly conductive canola oil where it was observed that electrode material may affect charge transfer. This points at the possible faradaic reactions that can occur at the surfaces of the electrodes. The supply voltage is applied to the sharp electrode and the grounded nozzle body constitutes the counter-electrode. The charge transfer is controlled by the electrochemical reactions on both the electrodes. The electrical performance study of the atomizer issuing a charged oil jet was conducted using three different nozzle body materials - brass, copper and stainless steel. Also, two sharp electrode materials - brass and stainless steel - were tested. The experimental results revealed that both the nozzle body material, as well as the sharp electrode material affected the spray and leak currents. Moreover, the effect of the sharp electrode material is quite significant. This research is supported by NSF Grant 1505276.

  15. FUEL CELL ELECTRODE MATERIALS

    Science.gov (United States)

    FUEL CELL ELECTRODE MATERIALS. RAW MATERIAL SELECTION INFLUENCES POLARIZATION BUT IS NOT A SINGLE CONTROLLING FACTOR. AVAILABLE...DATA INDICATES THAT AN INTERRELATIONSHIP OF POROSITY, AVERAGE PORE VOLUME, AND PERMEABILITY CONTRIBUTES TO ELECTRODE FUEL CELL BEHAVIOR.

  16. MODIS Collection 6 Clear Sky Restoral (CSR): Filtering Cloud Mast 'Not Clear' Pixels

    Science.gov (United States)

    Meyer, Kerry G.; Platnick, Steven Edward; Wind, Galina; Riedi, Jerome

    2014-01-01

    Correctly identifying cloudy pixels appropriate for the MOD06 cloud optical and microphysical property retrievals is accomplished in large part using results from the MOD35 1km cloud mask tests (note there are also two 250m subpixel cloud mask tests that can convert the 1km cloudy designations to clear sky). However, because MOD35 is by design clear sky conservative (i.e., it identifies "not clear" pixels), certain situations exist in which pixels identified by MOD35 as "cloudy" are nevertheless likely to be poor retrieval candidates. For instance, near the edge of clouds or within broken cloud fields, a given 1km MODIS field of view (FOV) may in fact only be partially cloudy. This can be problematic for the MOD06 retrievals because in these cases the assumptions of a completely overcast homogenous cloudy FOV and 1-dimensional plane-parallel radiative transfer no longer hold, and subsequent retrievals will be of low confidence. Furthermore, some pixels may be identified by MOD35 as "cloudy" for reasons other than the presence of clouds, such as scenes with thick smoke or lofted dust, and should therefore not be retrieved as clouds. With such situations in mind, a Clear Sky Restoral (CSR) algorithm was introduced in C5 that attempts to identify pixels expected to be poor retrieval candidates. Table 1 provides SDS locations for CSR and partly cloudy (PCL) pixels.

  17. Dry Electrode Harness System For Wireless 12-LEAD ECG Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The dry-electrode harness is composed of a variety of components.  The harness interfaces with the human via a commercial-off-the-shelf (COTS) FDA cleared dry...

  18. A Simple Hydrogen Electrode

    Science.gov (United States)

    Eggen, Per-Odd

    2009-01-01

    This article describes the construction of an inexpensive, robust, and simple hydrogen electrode, as well as the use of this electrode to measure "standard" potentials. In the experiment described here the students can measure the reduction potentials of metal-metal ion pairs directly, without using a secondary reference electrode. Measurements…

  19. Microresonator electrode design

    Science.gov (United States)

    Olsson, III, Roy H.; Wojciechowski, Kenneth; Branch, Darren W.

    2016-05-10

    A microresonator with an input electrode and an output electrode patterned thereon is described. The input electrode includes a series of stubs that are configured to isolate acoustic waves, such that the waves are not reflected into the microresonator. Such design results in reduction of spurious modes corresponding to the microresonator.

  20. Insulated ECG electrodes

    Science.gov (United States)

    Portnoy, W. M.; David, R. M.

    1973-01-01

    Insulated, capacitively coupled electrode does not require electrolyte paste for attachment. Other features of electrode include wide range of nontoxic material that may be employed for dielectric because of sputtering technique used. Also, electrode size is reduced because there is no need for external compensating networks with FET operational amplifier.

  1. STS-69 Clears the tower

    Science.gov (United States)

    1995-01-01

    A pack of astronauts that run under the banner Dog Crew II heads for the stars. Liftoff of the Space Shuttle Endeavour from Launch Pad 39A occurred at 11:09:00.052 a.m. EDT, Sept. 7, 1995. 'Every dog has its day and today is your day,' KSC Orbiter Test Conductor Roger Gillette pledged to STS-69 Mission Commander David M. Walker, Pilot Kenneth D. Cockrell, Payload Commander James S. Voss and Mission Specialists Michael L. Gernhardt and James H. Newman prior to launch. The STS-69 astronaut crew developed a strong sense of comaraderie as they went through their flight training, and dubbed themselves the Dog Crew II to carry on a tradition that arose during an earlier Shuttle flight -- STS-53 -- to which both Voss and Walker were assigned. Each crew member adopted a dog-theme name: Walker is Red Dog; Cockrell, Cujo; Voss, Dogface; Newman, Pluto; and Gernhardt, the only space rookie, Underdog. A special patch, featuring a bulldog in a doghouse shaped like the Space Shuttle, was designed for the astronauts and other flight team members to wear. The Dog Crew II is embarking on an 11-day multifaceted mission featuring two free-flying scientific research spacecraft as well as a host of experiments in both the payload bay and the middeck. Also scheduled is an extravehicular activity, or spacewalk.

  2. Comparative properties of optically clear epoxy encapsulants

    Science.gov (United States)

    Edwards, Maury; Zhou, Yan

    2001-12-01

    Three epoxy systems were evaluated for physical dn optical properties. The three systems chosen for the study were selected on the basis of their optical clarity, color and chemistry. Three distinctly different chemistries were chosen, aromatic epoxy-amine cured. Aromatic epoxy- anhydride cured and cycloaliphatic epoxy-anhydride cured. All three systems remained optically clear and water-white after full cure. The three selected systems were tested for physical properties, adhesion and light transmission properties. Light transmission was measured after thermal and humidity exposure. Adhesion was measured after humidity exposure only. Both of the epoxy-anhydride systems performed well in optical properties but poorer in adhesion as compared to the epoxy-amine system. The aromatic epoxy- amine system discolored badly during thermal exposure at 100 C. Data generated from this work will be used in selecting clear encapsulating materials for photonics applications. No single system offers optimal performance in all areas. The best compromise material is the aromatic epoxy-anhydride system.

  3. Montagem de um sistema para medidas galvanostáticas simultâneas em mais de uma célula The constrution of a multi-cell galvanostatic equipament for accelerated stability electrode test

    Directory of Open Access Journals (Sweden)

    Victor Solymossy

    2007-10-01

    Full Text Available The present work deals with the design and construction of an equipment for muti-cell accelerated stability test measurements (AST of dimensionally stable anodes (DSA. The equipment was built using only components that were available in the laboratory. Measurements of three electrochemical cells can be performed using the developed software. The acquisition time interval and the cut-off potencial can be set by the user. Experimental data for RuO2 electrodes obtained with the built equipment are in agreement with the literature.

  4. Improved technology for manufacture of carbon electrodes

    Indian Academy of Sciences (India)

    A Platon; A Dumbrava; N Iutes-Petrescu; Luzia Simionescu

    2000-02-01

    Current industrial carbon electrodes are typically manufactured by blending petroleum coke particles (the filler) with molten coal tar pitch (the binder) and extruding the resultant mix to form the `green electrode’. This is then baked under controlled conditions. In case of usage as anodes in steel electric furnaces (or as other carbon and graphite products), the electrodes could undergo further processing like pitch impregnation or graphitization. During heat treatment, some of the organics are destructively distilled, vaporized or decomposed, resulting in carbon deposition in the electrode. As the vaporized materials exit the body of the electrode they cause porosity in the walls, which results in reduction in density, current carrying capacity and flexural strength. The paper presents investigations to improve some physico-chemical characteristics of these electrodes (such as coefficient of thermal expansion, mechanical strengths, density, pore volume, porosity etc.), obtained in different manufacture steps, by addition of varieties of coal tar pitch. These include attempts to improve the chemical compatibility of the coke-pitch system in the mixture and establish the method and the point of introduction of additive, the concentration required and appropriate analytical control during the entire manufacture. Methods of analysis used include thermogravimetry and porosimetry. The microstructure of the electrodes is investigated through a wide range and the data obtained include pore size and pore volume distribution, surface area, porosity, particle size distribution and type of pores. The overall results clearly indicate better characteristics and performance for electrodes with additives as against electrodes without them, such as lower porosity, lower thermal expansion coefficients and greater mechanical strength. These data are analyzed with respect to the process step and electrode type.

  5. Development and application of double membrane modified antimony pH electrode and its testing instrument%双层膜锑pH电极及其测试仪的研制与应用

    Institute of Scientific and Technical Information of China (English)

    盛庆元; 张西良; 李萍萍; 刘丽晨; 陈书田

    2013-01-01

    The value of pH is a key chemical parameter in the field of industrial and agricultural production, medicine, environmental protection and other fields. At present, commercial glass pH electrodes have been widely used in soil pH test in the laboratory due to its convenience and reliability. But with turbid and vibrate systems in the filed like on-the-go pH mapping, glass electrode cannot be used because of its brittleness of the glass membrane, sluggish response, which are difficult to miniaturize and planarize based on current manufacturing technologies. In this work, a simple, flexible, inexpensive and effective way to make bilayer membrane modified antimony pH electrode was presented and one pH tester was developed. The surface of the obtained antimony wire was oxidized in sodium dioxide melt to fabricate an antimony oxide film for pH sensing as first layer. The second layer was Nafion membrane with selective characteristics, which was coated after the first layer. The sensing response and open-circuit potential of the electrode had a good linear relationship (R2=0.997) with pH value in the test solution, which also exhibited small hysteresis, fast response than that of bare antimony pH electrode. The open-circuit potential of the electrode was almost drift-free, with an average variation as small as 0.1mV over an hour. Ion interference experiment showed that this electrode has good selectivity with common ions (Na+, K+, Ca2+, Cl-, Br-) in soil, redox ion([Fe(CN)6]3-, [Fe(CN)6]4-) and citrate ions ( C6H5O73-). The bilayer membrane modified antimony pH electrode and the Ag/AgCl reference electrode as sensor were employed to pH tester, which was designed based on 16 bit low power consumption microcontroller (Sunplus SPCE061A). Tester readings in soil turbid solution under controlled in the lab were compared with the data obtained by standard protocols of soil. The tests demonstrated a high degree of linearity between standard laboratory values and turbid soil

  6. Handbook of reference electrodes

    CERN Document Server

    Inzelt, György; Scholz, Fritz

    2013-01-01

    Reference Electrodes are a crucial part of any electrochemical system, yet an up-to-date and comprehensive handbook is long overdue. Here, an experienced team of electrochemists provides an in-depth source of information and data for the proper choice and construction of reference electrodes. This includes all kinds of applications such as aqueous and non-aqueous solutions, ionic liquids, glass melts, solid electrolyte systems, and membrane electrodes. Advanced technologies such as miniaturized, conducting-polymer-based, screen-printed or disposable reference electrodes are also covered. Essen

  7. Pocket ECG electrode

    Science.gov (United States)

    Lund, Gordon F. (Inventor)

    1982-01-01

    A low-noise electrode suited for sensing electrocardiograms when chronically and subcutaneously implanted in a free-ranging subject. The electrode comprises a pocket-shaped electrically conductive member with a single entrance adapted to receive body fluids. The exterior of the member and the entrance region is coated with electrical insulation so that the only electrolyte/electrode interface is within the member remote from artifact-generating tissue. Cloth straps are bonded to the member to permit the electrode to be sutured to tissue and to provide electrical lead flexure relief.

  8. 17 CFR 39.4 - Procedures for implementing derivatives clearing organization rules and clearing new products.

    Science.gov (United States)

    2010-04-01

    ... derivatives clearing organization rules and clearing new products. 39.4 Section 39.4 Commodity and Securities... implementing derivatives clearing organization rules and clearing new products. (a) Request for approval of... of § 40.6 of this chapter. (c) Acceptance of new products for clearing. (1) A dormant...

  9. Membrane Bioprobe Electrodes

    Science.gov (United States)

    Rechnitz, Garry A.

    1975-01-01

    Describes the design of ion selective electrodes coupled with immobilized enzymes which operate either continuously or on drop-sized samples. Cites techniques for urea, L-phenylalanine and amygdalin. Micro size electrodes for use in single cells are discussed. (GH)

  10. Electrochemical testing of composite electrodes of (La1−xSrx)sMnO3 and doped ceria in NO-containing atmosphere

    DEFF Research Database (Denmark)

    Werchmeister, Rebecka Maria Larsen; Kammer Hansen, Kent; Mogensen, Mogens Bjerg

    2012-01-01

    The possibility of using electrochemical cells for removal of NO x from an exhaust gas with excess O2 has been examined. (La1−x Sr x ) s MnO3 (LSM) and ceria doped with Pr or Gd were selected as electrode materials and investigated in three-electrode cells. The electrodes were characterised elect...

  11. A semiconductor based electrode

    Energy Technology Data Exchange (ETDEWEB)

    Khamatani, A.; Kobayasi, K.

    1983-03-30

    The semiconductor electrode is submerged into an electrolyte which is held in the illuminated chamber. The other electrode is placed in a dark chamber connected with the channel to be illuminated, which has a partition in the form of a membrane. An electric current flows in the external circuit of the element with illumination of the first electrode. The illuminated electrode is covered with a thin film of a substance which is stable with the action of the electrolyte. The film is made of Si02, A1203, GaN or A1N. The protective coating makes it possible to use materials less stable than Ti02 in a rutile modification, but which have higher characteristics than the GaP, GaAs, CdS and InP, for making the electrode.

  12. Testing epitaxial Co{sub 1.5}Fe{sub 1.5}Ge(001) electrodes in MgO-based magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Neggache, A. [Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre lès Nancy (France); Synchrotron SOLEIL-CNRS, L' Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette (France); Hauet, T.; Petit-Watelot, S.; Boulet, P.; Andrieu, S., E-mail: stephane.andrieu@univ-lorraine.fr [Institut Jean Lamour, UMR CNRS 7198, Université de Lorraine, 54506 Vandoeuvre lès Nancy (France); Bertran, F.; Le Fèvre, P.; Ohresser, P. [Synchrotron SOLEIL-CNRS, L' Orme des Merisiers, Saint-Aubin BP48, 91192 Gif-sur-Yvette (France); Devolder, T. [Institut d' Electronique Fondamentale, CNRS, UMR 8622, 91405 Orsay (France); Mewes, C. [Department of Physics and Astronomy/Center for Materials for Information Technology, University of Alabama, Tuscaloosa, Alabama 35487 (United States); Maat, S.; Childress, J. R. [San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States)

    2014-06-23

    The ability of the full Heusler alloy Co{sub 1.5}Fe{sub 1.5}Ge(001) (CFG) to be a Half-Metallic Magnetic (HMM) material is investigated. Epitaxial CFG(001) layers were grown by molecular beam epitaxy. The results obtained using electron diffraction, X-ray diffraction, and X-ray magnetic circular dichroism are consistent with the full Heusler structure. The pseudo-gap in the minority spin density of state typical in HMM is examined using spin-resolved photoemission. Interestingly, the spin polarization found to be negative at E{sub F} in equimolar CoFe(001) is observed to shift to positive values when inserting Ge in CoFe. However, no pseudo-gap is found at the Fermi level, even if moderate magnetization and low Gilbert damping are observed as expected in HMM materials. Magneto-transport properties in MgO-based magnetic tunnel junctions using CFG electrodes are investigated via spin and symmetry resolved photoemission.

  13. Intelligibility of Clear Speech: Effect of Instruction

    Science.gov (United States)

    Lam, Jennifer; Tjaden, Kris

    2013-01-01

    Purpose: The authors investigated how clear speech instructions influence sentence intelligibility. Method: Twelve speakers produced sentences in habitual, clear, hearing impaired, and overenunciate conditions. Stimuli were amplitude normalized and mixed with multitalker babble for orthographic transcription by 40 listeners. The main analysis…

  14. Unusual clear cell variant of epithelioid mesothelioma.

    Science.gov (United States)

    Dessy, E; Falleni, M; Braidotti, P; Del Curto, B; Panigalli, T; Pietra, G G

    2001-12-01

    Clear cell mesothelioma is an extremely rare neoplasm of the pleura, which can easily be mistaken for a metastasis of clear cell carcinoma to the pleura. We report here the histochemical, immunohistochemical, and ultrastructural aspects of a new case of clear cell pleural mesothelioma in a 52-year-old man with no known asbestos exposure. He was admitted to the hospital for recurrent pleural effusion, which was negative for neoplastic cells at the cytologic examination. A partial decortication of the right pleura was performed. The morphologic, immunohistochemical, and ultrastructural features reported for this case are consistent with the diagnosis of clear cell mesothelioma. The differential diagnosis and immunohistochemical features in comparison with other clear cell neoplasms are discussed.

  15. SNOW CLEARING SERVICE WINTER 2001-2002

    CERN Multimedia

    ST-HM Group; Tel. 72202

    2001-01-01

    As usual at this time of the year, the snowing clearing service, which comes under the control of the Transport Group (ST-HM), is preparing for the start of snow-clearing operations (timetable, stand-by service, personnel responsible for driving vehicles and machines, preparation of useful and necessary equipment, work instructions, etc.) in collaboration with the Cleaning Service (ST-TFM) and the Fire Brigade (TIS-FB). The main difficulty for the snow-clearing service is the car parks, which cannot be properly cleared because of the presence of CERN and private vehicles parked there overnight in different parts of the parking areas. The ST-HM Transport Group would therefore like to invite you to park vehicles together in order to facilitate the access of the snow ploughs, thus allowing the car parks to be cleared more efficiently before the personnel arrives for work in the mornings.

  16. Nanowire Electrodes for Advanced Lithium Batteries

    Directory of Open Access Journals (Sweden)

    Lei eHuang

    2014-10-01

    Full Text Available Since the commercialization of lithium ion batteries (LIBs in the past two decades, rechargeable LIBs have become widespread power sources for portable devices used in daily life. However, current demands require higher energy density and power density of batteries. The electrochemical energy storage performance of LIBs could be improved by applying nanomaterial electrodes, but their fast capacity fading is still one of the key limitations and the mechanism needs to be clearly understood. Single nanowire electrode devices are considered as a versatile platform for in situ probing the direct relationship between electrical transport, structure change, and other properties of the single nanowire electrode along with the charge/discharge process. The results indicate the conductivity decrease of the nanowire electrode and the structural disorder/destruction during electrochemical reactions which limit the cycling performance of LIBs. Based on the in situ observations, some feasible structure architecture strategies, including prelithiation, coaxial structure, nanowire arrays and hierarchical structure architecture, are proposed and utilized to restrain the conductivity decrease and structural disorder/destruction. Further, the applications of nanowire electrodes in some beyond Li-ion batteries, such as Li-S and Li-air battery, are also described.

  17. Field Emission Measurements from Niobium Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    M. BastaniNejad, P.A. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, R. Mammei, M. Poelker

    2011-03-01

    Increasing the operating voltage of a DC high voltage photogun serves to minimize space charge induced emittance growth and thereby preserve electron beam brightness, however, field emission from the photogun cathode electrode can pose significant problems: constant low level field emission degrades vacuum via electron stimulated desorption which in turn reduces photocathode yield through chemical poisoning and/or ion bombardment and high levels of field emission can damage the ceramic insulator. Niobium electrodes (single crystal, large grain and fine grain) were characterized using a DC high voltage field emission test stand at maximum voltage -225kV and electric field gradient > 10MV/m. Niobium electrodes appear to be superior to diamond-paste polished stainless steel electrodes.

  18. Solid Reference Electrode of Metallurgical Oxygen Sensor

    Institute of Scientific and Technical Information of China (English)

    LOU Tian-jun; KONG Xiang-hua; HUANG Ke-qin; LIU Qing-guo

    2006-01-01

    The thermal equilibrium state of the reference electrode was investigated. The results show that the temperature difference between the inside and the outside of zirconia tube was very small and the Seebeck effect can be ignored after the sensor was dipped into liquid steel for more than 2 s. A special sensor was designed to test the relation between the EMF (electromotive force) of sensor and the thermal equilibrium state of the reference electrode. Based on these results, it is suggested that the peak in EMF curve was caused by the change of oxygen potential in reference electrode before the thermal equilibrium was reached. If NiO was added by 2%-5% to the Cr/Cr2O3 reference electrode, the peak in EMF curve could be eliminated.

  19. Understanding the Effects of Electrode Formulation on the Mechanical Strength of Composite Electrodes for Flexible Batteries.

    Science.gov (United States)

    Gaikwad, Abhinav M; Arias, Ana Claudia

    2017-02-22

    Flexible lithium-ion batteries are necessary for powering the next generation of wearable electronic devices. In most designs, the mechanical flexibility of the battery is improved by reducing the thickness of the active layers, which in turn reduces the areal capacity and energy density of the battery. The performance of a battery depends on the electrode composition, and in most flexible batteries, standard electrode formulation is used, which is not suitable for flexing. Even with considerable efforts made toward the development of flexible lithium-ion batteries, the formulation of the electrodes has received very little attention. In this study, we investigate the relation between the electrode formulation and the mechanical strength of the electrodes. Peel and drag tests are used to compare the adhesion and cohesion strength of the electrodes. The strength of an electrode is sensitive to the particle size and the choice of polymeric binder. By optimizing the electrode composition, we were able to fabricate a high areal capacity (∼2 mAh/cm(2)) flexible lithium-ion battery with conventional metal-based current collectors that shows superior electrochemical and mechanical performance in comparison to that of batteries with standard composition.

  20. Pitch ranking, electrode discrimination, and physiological spread-of-excitation using Cochlear's dual-electrode mode.

    Science.gov (United States)

    Goehring, Jenny L; Neff, Donna L; Baudhuin, Jacquelyn L; Hughes, Michelle L

    2014-08-01

    This study compared pitch ranking, electrode discrimination, and electrically evoked compound action potential (ECAP) spatial excitation patterns for adjacent physical electrodes (PEs) and the corresponding dual electrodes (DEs) for newer-generation Cochlear devices (Cochlear Ltd., Macquarie, New South Wales, Australia). The first goal was to determine whether pitch ranking and electrode discrimination yield similar outcomes for PEs and DEs. The second goal was to determine if the amount of spatial separation among ECAP excitation patterns (separation index, Σ) between adjacent PEs and the PE-DE pairs can predict performance on the psychophysical tasks. Using non-adaptive procedures, 13 subjects completed pitch ranking and electrode discrimination for adjacent PEs and the corresponding PE-DE pairs (DE versus each flanking PE) from the basal, middle, and apical electrode regions. Analysis of d' scores indicated that pitch-ranking and electrode-discrimination scores were not significantly different, but rather produced similar levels of performance. As expected, accuracy was significantly better for the PE-PE comparison than either PE-DE comparison. Correlations of the psychophysical versus ECAP Σ measures were positive; however, not all test/region correlations were significant across the array. Thus, the ECAP separation index is not sensitive enough to predict performance on behavioral tasks of pitch ranking or electrode discrimination for adjacent PEs or corresponding DEs.

  1. Nanocomposite electrodes made of carbon nanofibers and black wax. Anodic stripping voltammetry of zinc and lead.

    Science.gov (United States)

    van Dijk, N; Fletcher, S; Madden, C E; Marken, F

    2001-11-01

    Nanocomposite electrodes offer exciting new possibilities in electroanalytical chemistry. In this preliminary study, nanocomposite electrodes made of carbon nanofibers and black wax were characterized and investigated as novel substrates for metal deposition and stripping processes. Carbon nanofibers were grown from ethylene-hydrogen gas mixtures over Fe-Ni-Cu (85:10:5) nanoparticle catalysts at 600 degrees C and then embedded in Apiezon black wax under vacuum at 140 degrees C. The resulting nanocomposite electrodes showed (i) good conductivity, (ii) a wide potential window in aqueous solutions, (iii) low background currents, (iv) near steady state voltammetric responses with substantial Faradaic currents and (v) sharply peaked fast scan metal stripping responses. Zinc is a notoriously difficult metal to determine in aqueous solutions, because its deposition and stripping are accompanied by hydrogen evolution at extreme negative potentials. It therefore provided a challenging test for our new nanocomposite electrode. Although numerous complications associated with the hydrogen evolution process could not be eliminated, remarkably clear voltammograms could be obtained even at scan rates of 40 V s(-1).

  2. Compact Electrochemical System Using On-Chip Sensor Electrodes and Integrated Devices

    Science.gov (United States)

    Yamazaki, Tomoyuki; Ikeda, Takaaki; Ishida, Makoto; Sawada, Kazuaki

    2011-04-01

    We report a compact electrochemical sensing system to implement cyclic voltammetry. This type of sensor needs a working electrode, counter electrode, and reference electrode, all of which were integrated on a single chip. The electrochemical system also needs a potentiostat and an input voltage-generating circuit, which were developed using on-chip active devices and a few discrete passive components. This is the first sensor system incorporating electrode-side input voltage generation for electrochemical measurements using an on-chip operational amplifier, which replaces a bulky external voltage controller. A continuous cyclic voltammetry measurement was conducted with a well-studied ferricyanide solution to demonstrate the operation of the intelligent sensor chip. A clear peak was observed and linearity to the target chemical concentration was obtained between the peak height and concentration of the ferricyanide solution. With potential for mass production and small size, this sensor chip could be the best candidate to realize point-of-care testing. This sensor chip is a milestone of a fully integrated electrochemical sensor chip.

  3. Note: electrode polarization of Galinstan electrodes for liquid impedance spectroscopy.

    Science.gov (United States)

    Mellor, Brett L; Kellis, Nathan A; Mazzeo, Brian A

    2011-04-01

    Electrode polarization is a significant obstacle in the impedance measurements of ionic liquids. An atomically smooth electrode surface could potentially reduce unwanted impedance contributions from electrode polarization. Liquid metal electrodes were formed by adhering Galinstan to acrylic plates in a parallel-plate capacitor arrangement. Electrode polarization was compared to a similar cell with stainless steel electrodes. The impedance of salt and protein solutions (β-lactoglobulin) was measured from 40 Hz to 110 MHz. Because of oxide layer formation, the performance of the Galinstan electrode is significantly different than the theoretical ideal.

  4. Soft, Comfortable Polymer Dry Electrodes for High Quality ECG and EEG Recording

    Directory of Open Access Journals (Sweden)

    Yun-Hsuan Chen

    2014-12-01

    Full Text Available Conventional gel electrodes are widely used for biopotential measurements, despite important drawbacks such as skin irritation, long set-up time and uncomfortable removal. Recently introduced dry electrodes with rigid metal pins overcome most of these problems; however, their rigidity causes discomfort and pain. This paper presents dry electrodes offering high user comfort, since they are fabricated from EPDM rubber containing various additives for optimum conductivity, flexibility and ease of fabrication. The electrode impedance is measured on phantoms and human skin. After optimization of the polymer composition, the skin-electrode impedance is only ~10 times larger than that of gel electrodes. Therefore, these electrodes are directly capable of recording strong biopotential signals such as ECG while for low-amplitude signals such as EEG, the electrodes need to be coupled with an active circuit. EEG recordings using active polymer electrodes connected to a clinical EEG system show very promising results: alpha waves can be clearly observed when subjects close their eyes, and correlation and coherence analyses reveal high similarity between dry and gel electrode signals. Moreover, all subjects reported that our polymer electrodes did not cause discomfort. Hence, the polymer-based dry electrodes are promising alternatives to either rigid dry electrodes or conventional gel electrodes.

  5. Soft, Comfortable Polymer Dry Electrodes for High Quality ECG and EEG Recording

    Science.gov (United States)

    Chen, Yun-Hsuan; de Beeck, Maaike Op; Vanderheyden, Luc; Carrette, Evelien; Mihajlović, Vojkan; Vanstreels, Kris; Grundlehner, Bernard; Gadeyne, Stefanie; Boon, Paul; Van Hoof, Chris

    2014-01-01

    Conventional gel electrodes are widely used for biopotential measurements, despite important drawbacks such as skin irritation, long set-up time and uncomfortable removal. Recently introduced dry electrodes with rigid metal pins overcome most of these problems; however, their rigidity causes discomfort and pain. This paper presents dry electrodes offering high user comfort, since they are fabricated from EPDM rubber containing various additives for optimum conductivity, flexibility and ease of fabrication. The electrode impedance is measured on phantoms and human skin. After optimization of the polymer composition, the skin-electrode impedance is only ∼10 times larger than that of gel electrodes. Therefore, these electrodes are directly capable of recording strong biopotential signals such as ECG while for low-amplitude signals such as EEG, the electrodes need to be coupled with an active circuit. EEG recordings using active polymer electrodes connected to a clinical EEG system show very promising results: alpha waves can be clearly observed when subjects close their eyes, and correlation and coherence analyses reveal high similarity between dry and gel electrode signals. Moreover, all subjects reported that our polymer electrodes did not cause discomfort. Hence, the polymer-based dry electrodes are promising alternatives to either rigid dry electrodes or conventional gel electrodes. PMID:25513825

  6. Stretchable Micro-Electrode Array

    Energy Technology Data Exchange (ETDEWEB)

    Maghribi, M; Hamilton, J; Polla, D; Rose, K; Wilson, T; Krulevitch, P

    2002-03-08

    This paper focuses on the design consideration, fabrication processes and preliminary testing of the stretchable micro-electrode array. We are developing an implantable, stretchable micro-electrode array using polymer-based microfabrication techniques. The device will serve as the interface between an electronic imaging system and the human eye, directly stimulating retinal neurons via thin film conducting traces and electroplated electrodes. The metal features are embedded within a thin ({approx}50 micron) substrate fabricated using poly (dimethylsiloxane) (PDMS), a biocompatible elastomeric material that has very low water permeability. The conformable nature of PDMS is critical for ensuring uniform contact with the curved surface of the retina. To fabricate the device, we developed unique processes for metalizing PDMS to produce robust traces capable of maintaining conductivity when stretched (5%, SD 1.5), and for selectively passivating the conductive elements. An in situ measurement of residual strain in the PDMS during curing reveals a tensile strain of 10%, explaining the stretchable nature of the thin metalized devices.

  7. Cupric Hexacyanoferrate Nanoparticle Modified Carbon Ceramic Composite Electrodes

    Institute of Scientific and Technical Information of China (English)

    WANG,Peng(王鹏); ZHU,Guo-Yi(朱果逸)

    2002-01-01

    Graphite powder-supported cupric hexacyanoferrate (CuHCF)nanoparticles were dispersed into methyltrimethoxysilane-based gels to produce a conducting carbon ceramic composite, which was used as electrode material to fabricate surface-renewable CuHCF-modified electrodes. Electrochemical behavior of the CuHCF-modified carbon ceramic composite electrodes was characterized using cyclic and square-wave voitammetry.Cyclic voltammograms at various scan rates indicated that peak currents were surface-confined at low scan rates. In the presence of glutathione, a clear electrocatalytic response was observed at the CuHCF-modified composite electrodes. In addition, the electrodes exhibited a distinct advantage of reproducible surface-renewal by simple mechanical polishing on emery paper, as well as ease of preparation, and good chemical and mechanical stability in a flowing stream.

  8. Cupric Hexacyanoferrate Nanoparticle Modified Carbon Ceramic Composite Electrodes

    Institute of Scientific and Technical Information of China (English)

    WANG,Peng; ZHU,Guo-Yi

    2002-01-01

    Graphite powder-supported cupric hexacyanoferrate(CuHCF) nanoparticles were dispersed into methyltrimethoxysilane-based gels to produce a conducting carbon ceramic composite,which was used as electrode materials to fabricate surface-renewable CuHCF-modified electrodes.Electrochemical behavior of the CuHCF-modified carbon ceramic composite electrodes was characterized using cyclic and square-wave voltammetry. Cyclinc voltammograms at various scan rates indicated that peak currents were suface-confined at low scan rates.In the presence of glutathione,a clear electrocatalytic response was observed at the CuHCF-modified composite electrodes.In addition,the electrodes exhibited a distinct advantage of reproducible surface-renewal by simple mechanical polishing on emery paper,as well as ease of preparation,and good chemical and mechanical stability in a flowing stream.

  9. High Altitude Clear Air Turbulence Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Air Force Flight Dynamics Laboratory conducted the High Altitude Clear Air Turbulence Project in the mid 1960s with the intention of better understanding air...

  10. Porous Electrode Studies.

    Science.gov (United States)

    1980-07-01

    representation and analysis for their observed current distributions. Simonsson won the young author’s award of the Electrochemical Society for his paper...and T. Katan, Proc. Symp. Energy Storage and Conversion, the Electrochemical Society 77-6, 770 (1977) The optimum thickness of porous electrodes is...Chloride Electrodes; Surface Morphology on Charging and Dis- charging," T. Katan, S. Szpak, and D. N. Bennion, The Electrochemical Society , 143rd National

  11. Clear cell myoepithelial carcinoma ex pleomorphic adenoma

    Directory of Open Access Journals (Sweden)

    Nikhil R Rabade

    2014-01-01

    Full Text Available Pleomorphic adenoma is the most common epithelial neoplasm of lacrimal gland. A clear cell myoepithelial carcinoma arising in the background of pleomorphic adenoma is common in the salivary glands but very rare in the lacrimal glands. We report the case of a 27 year old man whose lacrimal gland pleomorphic adenoma recurred several times over a period of four years and ultimately evolved into a clear cell myoepithelial carcinoma ex pleomorphic adenoma.

  12. CO2 efflux from cleared mangrove peat.

    Directory of Open Access Journals (Sweden)

    Catherine E Lovelock

    Full Text Available BACKGROUND: CO(2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. METHODOLOGY/PRINCIPAL FINDINGS: We measured CO(2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO(2 efflux. CO(2 efflux from soils declines from time of clearing from ∼10,600 tonnes km(-2 year(-1 in the first year to 3000 tonnes km(2 year(-1 after 20 years since clearing. Disturbing peat leads to short term increases in CO(2 efflux (27 umol m(-2 s(-1, but this had returned to baseline levels within 2 days. CONCLUSIONS/SIGNIFICANCE: Deforesting mangroves that grow on peat soils results in CO(2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks.

  13. Sensor employing internal reference electrode

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention concerns a novel internal reference electrode as well as a novel sensing electrode for an improved internal reference oxygen sensor and the sensor employing same.......The present invention concerns a novel internal reference electrode as well as a novel sensing electrode for an improved internal reference oxygen sensor and the sensor employing same....

  14. Quantification of motion artifact in ECG electrode design.

    Science.gov (United States)

    Kearney, Kenneth; Thomas, Chris; McAdams, Eric

    2007-01-01

    We have developed a more accurate and reproducible method of quantifying motion artifact in ECG (electrocardiogram) electrodes to assist in electrode assessment and design. It uses an algorithm developed by Sensor Technology & Devices Ltd. to reliably overcome the variation in results due to differing skin types and other causes of spurious readings such as reproducibility of movements used. The method combines a clear, concise experimental protocol with a software package and DSP algorithm to produce a transferable result for one pair of electrodes that can be used for comparison.

  15. Amplifier input impedance in dry electrode ECG recording.

    Science.gov (United States)

    Assambo, Cedric; Burke, Martin J

    2009-01-01

    This paper presents a novel approach for designing the front-end of instrumentation amplifiers for use in dry electrode recording of the human electrocardiogram (ECG). The method relies on information provided by the characterization of the skin-electrode interface and the analysis of low frequency ECG criteria defined by international standards. Marginal measurements of capacitive elements of the skin-electrode interface as small as 0.01 microF, suggest values of input impedance in the order of 1.3 GOmega. However, results in 99% of the data analyzed indicate that a recording amplifier providing an input impedance of 500 MOmega should ensure clear signal sensing without distortion.

  16. Recording the oscillatory potentials of the electroretinogram with the DTL electrode.

    Science.gov (United States)

    Lachapelle, P; Benoit, J; Little, J M; Lachapelle, B

    1993-01-01

    Suprathreshold photopic oscillatory potentials recorded with a DTL electrode were compared to those obtained with a Lovac corneal electrode. The overall oscillatory potential response (sum of oscillatory potentials) recorded with the DTL electrode was half of that obtained with the Lovac electrode. However, there was no evidence of a selective attenuation (or amplification) of any given oscillatory potential with the DTL electrode. Similarly, the oscillatory potential relative amplitude ratios and the peak times of the oscillatory potentials were identical for both electrodes. Our findings clearly indicate that the DTL electrode is adequate to record the high-frequency oscillatory potentials. Given the low cost and ease of use, as well as the disposable nature of the DTL electrode, we believe that electroretinographic specialists should seriously consider a wider utilization.

  17. Hollow electrode loose plate SOFC design

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, B.C.; Dongen, B.A.M. van; Monaster, G.A. [Seed Capital Investments B.V., Utrecht (Netherlands); Roosmalen, J.A.M. van; Plaisier, K.H.; Schoonman, J. [Delft Univ. of Technology (Netherlands). Lab. for Applied Inorganic Chemistry

    1995-12-31

    A novel planar SOFC design is presented, based on the loose stacking of hollow electrode elements, conventional plate type electrolytes and interconnectors. This facilitates free thermal expansion during operation, and thermal cycling, thereby significantly improving prospects for reliable SOFC operation in power generation practice. Each individual element only consists of one material, eliminating the need for sealing and for matching thermal expansion coefficients of fuel cell components. Application of hollow electrodes results in an inherent manifolding of the gas streams eliminating the need for seals at the fuel cell stack itself. The design has been tested at laboratory scale and a small working prototype fuel cell has been successfully tested.

  18. Shanghai Clearing House to Roll out Renminbi-denominated Copper Clearing Operations in Free Trade Zone

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>Clearing House Financial Markets Co.,Ltd.(Shanghai Clearing House)General Manager Xie Zhong told the media recently at the briefing of the international symposium of"Reform Deepening and Mechanism Innovation of the Post-crisis Kerb Market",Shanghai Clearing House will explore the feasibility of carrying out bond business in

  19. The Effect of Composition of Different Ecotoxicological Test Media on Free and Bioavailable Copper from CuSO4 and CuO Nanoparticles: Comparative Evidence from a Cu-Selective Electrode and a Cu-Biosensor

    Directory of Open Access Journals (Sweden)

    Angela Ivask

    2011-11-01

    Full Text Available The analysis of (bioavailable copper in complex environmental settings, including biological test media, is a challenging task. In this study, we demonstrated the potential of a recombinant Pseudomonas fluorescens-based biosensor for bioavailability analysis of CuSO4 and CuO nanoparticles (nano-CuO in seventeen different ecotoxicological and microbiologial test media. In parallel, free Cu in these test media was analysed using Cu-ion selective electrode (Cu-ISE. In the case of CuSO4, both free and bioavailable Cu decreased greatly with increasing concentration of organics and phosphates in the tested media. A good correlation between free and bioavailable Cu was observed (r = 0.854, p < 0.01 indicating that the free Cu content in biological test media may be a reasonably good predictor for the toxicity of CuSO4. As a proof, it was demonstrated that when eleven EC50 values for CuSO4 from different organisms in different test media were normalized for the free Cu in these media, the difference in these EC50 values was decreased from 4 to 1.8 orders of magnitude. Thus, toxicity of CuSO4 to these organisms was attributed to the properties of the test media rather than to inherent differences in sensitivity between the test organisms. Differently from CuSO4, the amount of free and bioavailable Cu in nano-CuO spiked media was not significantly correlated with the concentration of organics in the test media. Thus, the speciation of nano-CuO in toxicological test systems was not only determined by the complexation of Cu ions but also by differential dissolution of nano-CuO in different test conditions leading to a new speciation equilibrium. In addition, a substantial fraction of nano-CuO that was not detectable by Cu-ISE (i.e., not present as free Cu-ions was bioavailable to Cu-biosensor bacteria. Thus, in environmental hazard analysis of (nano particulate materials, biosensor analysis may be more informative than other analytical techniques. Our

  20. Clear plastic cups: a childhood choking hazard.

    Science.gov (United States)

    Weiss, R L; Goldstein, M N; Dharia, A; Zahtz, G; Abramson, A L; Patel, M

    1996-11-01

    The disposable plastic beverage cup is not usually regarded as hazardous to young children. Certain varieties of these products however, are manufactured from a brittle, clear plastic that easily cracks and fragments. While most conscientious parents keep their children safe from peanuts, balloons, and other known choking hazards, a child can surreptitiously bite a cup edge and aspirate the fragment. We report two cases of foreign body aspiration involving clear plastic cups that went undetected one of which remained 21 months following a negative rigid bronchoscopy. Diagnostic difficulties are related to the transparency and radiolucency of these objects. When suspicious of foreign body aspiration in children, otolaryngologists should inquire about the availability of clear plastic cups in the household and be mindful of the diagnostic pitfalls. Further investigations including CT scanning and repeat bronchoscopy may be helpful in cases of suspected missed foreign bodies. An educational campaign aimed at prevention and placement of product package warning labels should be established.

  1. Clear cell carcinoma of the female genital tract (not everything is as clear as it seems).

    Science.gov (United States)

    Offman, Saul L; Longacre, Teri A

    2012-09-01

    Clear cell carcinoma has a storied history in the female genital tract. From the initial designation of ovarian clear cell adenocarcinoma as "mesonephroma" to the linkage between vaginal clear cell carcinoma and diethylstilbestrol exposure in utero, gynecologic tract clear cell tumors have puzzled investigators, posed therapeutic dilemmas for oncologists, and otherwise presented major differential diagnostic challenges for pathologists. One of the most common errors in gynecologic pathology is misdiagnosis of clear cell carcinoma, on both frozen section and permanent section. Given the poor response to platinum-based chemotherapy for advanced-stage disease and increased risk of thromboembolism, accurate diagnosis of clear cell carcinoma is important in the female genital tract. This review (1) presents the clinical and pathologic features of female genital tract clear cell carcinomas; (2) highlights recent molecular developments; (3) identifies areas of potential diagnostic confusion; and (4) presents solutions for these diagnostic problems where they exist.

  2. Working electrode holder and electrochemical cell

    DEFF Research Database (Denmark)

    2016-01-01

    The present disclosure relates to a holder for a test object, more specifically to a holder for measuring electrochemical properties of the test object. One embodiment relates to a working electrode holder for measuring electrochemical properties of a front surface of a test object in a liquid...... in the bottom surface and configured for passage of said liquid, such that liquid is able to pass onto the electrically contacted front surface. The holder may be used in an electrochemical cell....

  3. The management of clear cell sarcoma

    NARCIS (Netherlands)

    Kuiper, DR; Hoekstra, HJ; Veth, RPH; Wobbes, T

    2003-01-01

    Clear cell sarcoma is a rare soft tissue tumour, constituting approximately 1% of all soft tissue sarcomas. Prognosis is reported to be poor due to the great propensity to metastasise regionally and distantly. In this paper, we report the surgical experience of two university hospitals. Both disease

  4. Clearing and settlement of exchange traded derivatives

    OpenAIRE

    John McPartland

    2009-01-01

    Derivatives are a class of financial instruments that derive their value from some underlying commodity, security, index, or other asset. Futures and options are common forms of derivatives. This article explains how clearing and settlement systems for exchange traded derivatives work.

  5. A New Ritodrine Selective Electrode and its Pharmaceutical Application

    Directory of Open Access Journals (Sweden)

    Reda Ammar

    2010-01-01

    Full Text Available A novel ritodrine hydrochloride ion-selective PVC membrane electrode based on ion-pair complex of ritodrine-tetra phenyl borate was prepared with di-n-butyl phosphate as a plasticizer. The influences of membrane composition, temperature, pH of the test solution and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian response over a wide ritodrine concentration range (1×10−5- 1×10−2 M with a slope of 59.33 mV decade−1 and was found to be very selective, precise and usable within the pH range 3-7.5. The standard electrode potentials, E°, were determined at different temperatures and used to calculate the isothermal temperature coefficient (dE°/dT of the electrode, which was 0.00075. The electrode was successfully used for potentiometric determination of ritodrine hydrochloride both in pure solutions and in pharmaceutical preparations.

  6. Investigation on a Novel Capacitive Electrode for Geophysical Surveys

    Directory of Open Access Journals (Sweden)

    Zhiyu Wang

    2016-01-01

    Full Text Available Nonpolarizable electrodes are applied widely in the electric field measurement for geophysical surveys. However, there are two major problems: (1 systematic errors caused by poor electrical contact in the high resistive terrains and (2 environmental damage associated with using nonpolarizable electrodes. A new alternative structure of capacitive electrode, which is capable of sensing surface potential through weak capacitive coupling, is presented to solve the above problems. A technique is introduced to neutralize distributed capacitance and input capacitance of the detection circuit. With the capacitance neutralization technique, the transmission coefficient of capacitive electrode remains stable when environmental conditions change. The simulation and field test results indicate that the new capacitive electrode has an operating bandwidth range from 0.1 Hz to 1 kHz. The capacitive electrodes have a good prospect of the applications in geophysical prospecting, especially in resistive terrains.

  7. Composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, S.T.; Pekala, R.W.; Kaschmitter, J.L.

    1997-05-06

    Carbon aerogels used as a binder for granulated materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy. 1 fig.

  8. Composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)

    1997-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivty and power to system energy.

  9. Standard test method for determining plutonium by controlled-potential coulometry in H2SO4 at a platinum working electrode

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1990-01-01

    1.1 This test method covers the determination of milligram quantities of plutonium in unirradiated uranium-plutonium mixed oxide having a U/Pu ratio range of 0.1 to 10. This test method is also applicable to plutonium metal, plutonium oxide, uranium-plutonium mixed carbide, various plutonium compounds including fluoride and chloride salts, and plutonium solutions. 1.2 The recommended amount of plutonium for each aliquant in the coulometric analysis is 5 to 10 mg. Precision worsens for lower amounts of plutonium, and elapsed time of electrolysis becomes impractical for higher amounts of plutonium. 1.3 The values stated in SI units are to be regarded as standard. No other units are to be regarded as standard. 1.4 This standard does not purport to address all of the safety concens, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precaution...

  10. The Composite Insertion Electrode

    DEFF Research Database (Denmark)

    Atlung, Sven; Zachau-Christiansen, Birgit; West, Keld;

    1984-01-01

    . The theoretical basis for such electrodes is discussedand, using a simplified model, equations are derived to describe the distribution of potential and current duringdischarge/charge operation. Under the assumption that the insertion compound particles are small enough to ensureequilibrium, and that the local...... electrode potential depends linearly on the degree of insertion, these equations are solvedto obtain analytical expressions for the discharge curve. It is shown that the parameters which determine the dischargebehavior for a given discharge current are simply related to the effective ionic and electronic...

  11. Ion-selective electrodes

    CERN Document Server

    Mikhelson, Konstantin N

    2013-01-01

    Ion-selective electrodes (ISEs) have a wide range of applications in clinical, environmental, food and pharmaceutical analysis as well as further uses in chemistry and life sciences. Based on his profound experience as a researcher in ISEs and a course instructor, the author summarizes current knowledge for advanced teaching and training purposes with a particular focus on ionophore-based ISEs. Coverage includes the basics of measuring with ISEs, essential membrane potential theory and a comprehensive overview of the various classes of ion-selective electrodes. The principles of constructing I

  12. Single Electrode Heat Effects

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Broers, G. H. J.

    1977-01-01

    SP, of theelectrode reaction. eta is the overvoltage at the electrode. This equation is appliedto a high temperature carbonate fuel cell. It is shown that the Peltier entropyterm by far exceeds the heat production due to the irreversible losses, and thatthe main part of heat evolved at the cathode is reabsorbed......The heat evolution at a single irreversibly working electrode is treated onthe basis of the Brønsted heat principle. The resulting equation is analogous to the expression for the total heat evolution in a galvanic cellwith the exception that –DeltaS is substituted by the Peltier entropy, Delta...

  13. Automatic detection of ECG electrode misplacement: a tale of two algorithms.

    Science.gov (United States)

    Xia, Henian; Garcia, Gabriel A; Zhao, Xiaopeng

    2012-09-01

    Artifacts in an electrocardiogram (ECG) due to electrode misplacement can lead to wrong diagnoses. Various computer methods have been developed for automatic detection of electrode misplacement. Here we reviewed and compared the performance of two algorithms with the highest accuracies on several databases from PhysioNet. These algorithms were implemented into four models. For clean ECG records with clearly distinguishable waves, the best model produced excellent accuracies (> = 98.4%) for all misplacements except the LA/LL interchange (87.4%). However, the accuracies were significantly lower for records with noise and arrhythmias. Moreover, when the algorithms were tested on a database that was independent from the training database, the accuracies may be poor. For the worst scenario, the best accuracies for different types of misplacements ranged from 36.1% to 78.4%. A large number of ECGs of various qualities and pathological conditions are collected every day. To improve the quality of health care, the results of this paper call for more robust and accurate algorithms for automatic detection of electrode misplacement, which should be developed and tested using a database of extensive ECG records.

  14. Reference Electrodes in Metal Corrosion

    Directory of Open Access Journals (Sweden)

    S. Szabó

    2010-01-01

    Full Text Available With especial regard to hydrogen electrode, the theoretical fundamentals of electrode potential, the most important reference electrodes and the electrode potential measurement have been discussed. In the case of the hydrogen electrode, it have been emphasised that there is no equilibrium between the hydrogen molecule (H2 and the hydrogen (H+, hydronium (H3O+ ion in the absence of a suitable catalyst. Taking into account the practical aspects as well, the theorectical basis of working of hydrogen, copper-copper sulphate, mercury-mercurous halide, silver-silver halide, metal-metal oxide, metal-metal sulphate and “Thalamid” electrodes, has been discussed.

  15. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  16. Contact dermatitis caused by ECG electrode paste.

    Science.gov (United States)

    Cochran, R J; Rosen, T

    1980-12-01

    A case of contact dermatitis caused by ECG electrode cream is presented and the pertinent literature is reviewed. Our patient was found to be allergic to propylene glycol. Patch-testing remains an invaluable tool in the evaluation of patients suspected of being allergic to ECG paste, creams, and gels.

  17. Does gently clearing the nasal passage affect odor identification?

    Directory of Open Access Journals (Sweden)

    Mitchell G. Spring

    2014-12-01

    Full Text Available Identifying scents in a wine’s bouquet is considered one of the most important steps in the process of wine tasting. An individual’s ability to successfully do this is dependent on the sense of smell; thus, altering the nasal microenvironment could have a powerful effect on the wine tasting experience. In the present study, we examined olfactory performance in healthy participants who cleared their nasal cavity before odorant presentations. Fifty undergraduate participants were assessed with a standardized test of olfaction requiring the recognition of a battery of odors. Half of these participants cleared mucus from their nasal cavities (by gently blowing their noses prior to the assessment. No difference was found in performance between those who cleared their nasal passages and those who did not. Further, data were not different than known population data from the test. These data suggest that gently clearing the nasal cavity before presentation of odorants bears no effect on the ability to perceive those odor qualities.

  18. Multiphoton microscopy of cleared mouse organs

    Science.gov (United States)

    Parra, Sonia G.; Chia, Thomas H.; Zinter, Joseph P.; Levene, Michael J.

    2010-05-01

    Typical imaging depths with multiphoton microscopy (MPM) are limited to less than 300 μm in many tissues due to light scattering. Optical clearing significantly reduces light scattering by replacing water in the organ tissue with a fluid having a similar index of refraction to that of proteins. We demonstrate MPM of intact, fixed, cleared mouse organs with penetration depths and fields of view in excess of 2 mm. MPM enables the creation of large 3-D data sets with flexibility in pixel format and ready access to intrinsic fluorescence and second-harmonic generation. We present high-resolution images and 3-D image stacks of the brain, small intestine, large intestine, kidney, lung, and testicle with image sizes as large as 4096×4096 pixels.

  19. Roadmap-Based Level Clearing of Buildings

    KAUST Repository

    Rodriguez, Samuel

    2011-01-01

    In this paper we describe a roadmap-based approach for a multi-agent search strategy to clear a building or multi-story environment. This approach utilizes an encoding of the environment in the form of a graph (roadmap) that is used to encode feasible paths through the environment. The roadmap is partitioned into regions, e.g., one per level, and we design region-based search strategies to cover and clear the environment. We can provide certain guarantees within this roadmap-based framework on coverage and the number of agents needed. Our approach can handle complex and realistic environments where many approaches are restricted to simple 2D environments. © 2011 Springer-Verlag.

  20. Clear cell odontogenic carcinoma: A rare case

    Directory of Open Access Journals (Sweden)

    Garima Jain

    2015-01-01

    Full Text Available Clear cell odontogenic carcinoma is a rare neoplasm with very few cases reported in the literature. We report a case of a 50-year-old female patient with the malignancy at a less common location. Diagnosis was given based on the histopathologic findings. The demographic data and understanding for this tumor needs to be strengthened by reporting all new cases, which are diagnosed, in literature.

  1. Internet compromise clears way for WSIS agreement

    CERN Multimedia

    Ermert, M

    2003-01-01

    A working group under the leadership of United Nations Secretary General Kofi Annan himself will try to resolve the deep differences on the question of Internet governance, officials said here. The group, whose exact membership wasn't immediately clear, is to propose a solution to the controversial issue that has given negotiators at the World Summit of the Information Society (WSIS) a headache (1/2 page).

  2. Submicron electrode gaps fabricated by gold electrodeposition at interdigitated electrodes

    NARCIS (Netherlands)

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

    2014-01-01

    Electrodes with submicron gaps are desired for achieving high amplification redox cycling sensors. In this contribution we report the use of electrodeposition of gold in order to decrease the inter-electrode spacing at interdigitated electrodes. Using this method submicron spacings can be obtained w

  3. Reproducibility of electroretinograms recorded with DTL electrodes.

    Science.gov (United States)

    Hébert, M; Lachapelle, P; Dumont, M

    The purpose of this study was to examine whether the use of the DTL fiber electrode yields stable and reproducible electroretinographic recordings. To do so, luminance response function, derived from dark-adapted electroretinograms, was obtained from both eyes of 10 normal subjects at two recording sessions spaced by 7-14 days. The data thus generated was used to calculate Naka-Rushton Vmax and k parameters and values obtained at the two recording sessions were compared. Our results showed that there was no significant difference in the values of Vmax and k calculated from the data generated at the two recording sessions. The above clearly demonstrate that the use of the DTL fiber electrode does not jeopardize, in any way, the stability and reproducibility of ERG responses.

  4. Dry EEG Electrodes

    Directory of Open Access Journals (Sweden)

    M. A. Lopez-Gordo

    2014-07-01

    Full Text Available Electroencephalography (EEG emerged in the second decade of the 20th century as a technique for recording the neurophysiological response. Since then, there has been little variation in the physical principles that sustain the signal acquisition probes, otherwise called electrodes. Currently, new advances in technology have brought new unexpected fields of applications apart from the clinical, for which new aspects such as usability and gel-free operation are first order priorities. Thanks to new advances in materials and integrated electronic systems technologies, a new generation of dry electrodes has been developed to fulfill the need. In this manuscript, we review current approaches to develop dry EEG electrodes for clinical and other applications, including information about measurement methods and evaluation reports. We conclude that, although a broad and non-homogeneous diversity of approaches has been evaluated without a consensus in procedures and methodology, their performances are not far from those obtained with wet electrodes, which are considered the gold standard, thus enabling the former to be a useful tool in a variety of novel applications.

  5. Single Electrode Heat Effects

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Broers, G. H. J.

    1977-01-01

    for the oxygen electrode reaction is estimatedfrom thermodynamic data and reasonable agreement with the experimentalresults is found. It is concluded that the main contribution to the Peltierentropy arises from the transition from gaseous to liquid state, whereas thetransfer entropies of the ionic species...

  6. Optical clearing of muscle with propylene glycol

    Science.gov (United States)

    Oliveira, Luís; Lage, Armindo; Clemente, Manuel Pais; Tuchin, Valery V.

    2010-02-01

    Skeletal muscle presents an internal fibrous structure. The existence of muscle fibers surrounded by interstitial fluid originates an internal step refractive index profile that causes light scattering. One way to minimize this effect inside a muscle is to perform an optical clearing treatment, using an adequate solution that presents a refractive index higher than the interstitial fluid. We have studied muscle spectral transmittance during sample immersion in propylene glycol. With the collection of transmittance spectra registered during a period of 20 minutes of immersion we could represent spectral transmittance evolution for several wavelengths and verify that the tissue samples have become more translucent. The optical clearing effect created in the tissue samples was characterized by an increase of 45% above the natural transmittance and the variations observed in tissue mass, pH and global refractive index. We also identified the initial mechanisms of agent diffusion into the tissue and consequent tissue dehydration from the spectral transmittance evolution. The histological analysis of variations caused in the internal structure of the tissues permitted to better explain the optical clearing effect created. Considering a mathematical model developed in previous studies, we could estimate the amount of agent that was inserted into the tissue samples.

  7. A novel method to prepare metal oxide electrode: Spin-coating with thermal decomposition

    Institute of Scientific and Technical Information of China (English)

    Hao Xu; Wei Yan; Cheng Li Tang

    2011-01-01

    In this work, we propose a new spin-coating method coupling with high thermal decomposition, to prepare the tin-antimony (Sn-Sb) oxide electrode. The character of the spin-coating electrode was compared with the dip-coating electrode through X-ray diffraction (XRD), scanning electron microscopy (SEM), accelerated life test, cyclic voltammetry, and electrolytic degradability. The results showed that the spin-coating electrode had a better defined crystal form, a smoother and more compact surface than that of the dip-coating electrode. Service time of the spin-coating electrode was determined to be longer than 15 h, and it was less than 2 min for the dip-coating electrode. Electrochemical characterization analysis showed that the electrolytic degradability of the spin-coating electrode is better than that of the dip-coating electrode.

  8. Simulations and design of microfabricated interdigitated electrodes for use in a gold nanoparticle enhanced biosensor.

    Science.gov (United States)

    Hermansen, Peter; MacKay, Scott; Wishart, David; Jie Chen

    2016-08-01

    Microfabricated interdigitated electrode chips have been designed for use in a unique gold-nanoparticle based biosensor system. The use of these electrodes will allow for simple, accurate, inexpensive, and portable biosensing, with potential applications in diagnostics, medical research, and environmental testing. To determine the optimal design for these electrodes, finite element analysis simulations were carried out using COMSOL Multiphysics software. The results of these simulations determined some of the optimal design parameters for microfabricating interdigitated electrodes as well as predicting the effects of different electrode materials. Finally, based on the results of these simulations two different kinds of interdigitated electrode chips were made using photolithography.

  9. Organic electrode coatings for next-generation neural interfaces.

    Science.gov (United States)

    Aregueta-Robles, Ulises A; Woolley, Andrew J; Poole-Warren, Laura A; Lovell, Nigel H; Green, Rylie A

    2014-01-01

    Traditional neuronal interfaces utilize metallic electrodes which in recent years have reached a plateau in terms of the ability to provide safe stimulation at high resolution or rather with high densities of microelectrodes with improved spatial selectivity. To achieve higher resolution it has become clear that reducing the size of electrodes is required to enable higher electrode counts from the implant device. The limitations of interfacing electrodes including low charge injection limits, mechanical mismatch and foreign body response can be addressed through the use of organic electrode coatings which typically provide a softer, more roughened surface to enable both improved charge transfer and lower mechanical mismatch with neural tissue. Coating electrodes with conductive polymers or carbon nanotubes offers a substantial increase in charge transfer area compared to conventional platinum electrodes. These organic conductors provide safe electrical stimulation of tissue while avoiding undesirable chemical reactions and cell damage. However, the mechanical properties of conductive polymers are not ideal, as they are quite brittle. Hydrogel polymers present a versatile coating option for electrodes as they can be chemically modified to provide a soft and conductive scaffold. However, the in vivo chronic inflammatory response of these conductive hydrogels remains unknown. A more recent approach proposes tissue engineering the electrode interface through the use of encapsulated neurons within hydrogel coatings. This approach may provide a method for activating tissue at the cellular scale, however, several technological challenges must be addressed to demonstrate feasibility of this innovative idea. The review focuses on the various organic coatings which have been investigated to improve neural interface electrodes.

  10. Transparent Electrodes with Nanotubes and Graphene for Printed Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Marcin Słoma

    2014-01-01

    Full Text Available We report here on printed electroluminescent structures containing transparent electrodes made of carbon nanotubes and graphene nanoplatelets. Screen-printing and spray-coating techniques were employed. Electrodes and structures were examined towards optical parameters using spectrophotometer and irradiation meter. Electromechanical properties of transparent electrodes are exterminated with cyclical bending test. Accelerated aging process was conducted according to EN 62137 standard for reliability tests of electronics. We observed significant negative influence of mechanical bending on sheet resistivity of ITO, while resistivity of nanotube and graphene based electrodes remained stable. Aging process has also negative influence on ITO based structures resulting in delamination of printed layers, while those based on carbon nanomaterials remained intact. We observe negligible changes in irradiation for structures with carbon nanotube electrodes after accelerated aging process. Such materials demonstrate a high application potential in general purpose electroluminescent devices.

  11. Sweat electrolytes test

    Science.gov (United States)

    Sweat test; Sweat chloride; Iontophoretic sweat test ... No special steps are needed before this test. ... The test is not painful. Some people have a tingling feeling at the site of the electrode. This feeling ...

  12. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1985-01-01

    Ion-Selective Electrode Reviews, Volume 7 is a collection of papers that covers the applications of electrochemical sensors, along with the versatility of ion-selective electrodes. The coverage of the text includes solid contact in membrane ion-selective electrodes; immobilized enzyme probes for determining inhibitors; potentiometric titrations based on ion-pair formation; and application of ion-selective electrodes in soil science, kinetics, and kinetic analysis. The text will be of great use to chemists and chemical engineers.

  13. The Nordic power market: Are there alternatives to expensive clearing?; Alternativer til kostbar clearing?

    Energy Technology Data Exchange (ETDEWEB)

    Nerdrum, Per Kaare; Poulsson, Christian

    2003-07-01

    The Enron scandal of 2002 has set focus on counter party risk in the Nordic power market and is an important cause of increased clearing of bilateral financial power contracts. The article discusses whether expensive clearing is always the best tool for dealing with counter party risk.

  14. Chiral Recognition of Amino Acids by Magnetoelectrodeposited Cu Film Electrodes

    Directory of Open Access Journals (Sweden)

    Iwao Mogi

    2011-01-01

    Full Text Available Chiral behavior of magnetoelectrodeposited (MED Cu film electrodes was investigated for the electrochemical reactions of amino acids. The Cu films were electrodeposited under a magnetic field of 5 T perpendicular to the electrode surface. Such MED Cu films were employed as an electrode, and cyclic voltammograms were measured for the electrochemical reactions of several kinds of amino acids. Chiral behavior was clearly observed as oxidation current difference between the enantiomers of alanine, aspartic acid, and glutamic acid. The MED film electrodes with the thickness of 50~500 nm exhibited such chiral behavior, and their surface morphologies had network structures, which could be induced by the micro-MHD effect.

  15. Pediatric evaluation of the ClearVoice™ speech enhancement algorithm in everyday life

    Directory of Open Access Journals (Sweden)

    Nathalie Noël-Petroff

    2013-12-01

    Full Text Available ClearVoice™ enables Advanced Bionics cochlear implant users to improve their speech understanding in difficult listening environments, without compromising performance in quiet situations. The aim of the study was to evaluate the benefits of ClearVoice in children. Children between six and fourteen years of age randomly tested two modalities of ClearVoice for one month each. The baseline program, HiRes 120™, and both ClearVoice programs were evaluated with a sentence test in quiet and noise. Parents and teachers completed a questionnaire related to everyday noisy situations. The switchover to ClearVoice was uneventful for both modalities. Adjustments to thresholds and comfort levels were required. Seven out of the nine children preferred a ClearVoice program. No impact of ClearVoice on performance in quiet was observed and both modalities of ClearVoice improved speech understanding in noise compared to the baseline program, significantly with ClearVoice high. Positive outcomes were obtained from the questionnaires and discussions with parents and children. This study showed that children benefited from using ClearVoice in their daily life. There was a clear trend towards improved speech understanding in noise with ClearVoice, without affecting performance in quiet; therefore ClearVoice can be used by children all day, without having to change programs.

  16. Inkjet printing of semitransparent electrodes for photovoltaic applications

    Science.gov (United States)

    Maisch, Philipp; Tam, Kai C.; Lucera, Luca; Fecher, Frank W.; Egelhaaf, Hans-Joachim; Scheiber, Horst; Maier, Eugen; Brabec, Christoph J.

    2016-09-01

    In this work we compare two different semitransparent inkjet printed electrodes for organic photovoltaic (OPV) applications. We highlight the processing as well as layer properties of the most commonly used silver grid/PEDOT:PSS electrodes and a newly developed inkjet printed silver nanowire (AgNW) mesh. Application of the different electrode types in fully inkjet printed organic solar cells reveals the superior performance of the AgNWs. Using them as bottom and top electrode, semitransparent solar cells with power conversion efficiencies (PCE) of up to 4.3 % are demonstrated. Comparable devices with silver grid electrodes reach a maximum PCE of 3.6 %. We identify shading of the opaque silver grids, which cover 10 % of the device area, and thermal stress introduced by the curing of the silver grid top electrodes as main factors for the losses. Furthermore, the silver grids do not only lower the short circuit current of the solar cell, but are also visually obstructive. The newly developed inkjet printed AgNW percolation network electrodes show high transparency of over 90 % at a sheet resistance of less than 20 Ω/□ and a very low haze of less than 3 %. This enables a clear view through semitransparent devices like organic light emitting diodes (OLEDS) or solar cells in which they can be used.

  17. Electroformed Electrodes for Electrical-Discharge Machining

    Science.gov (United States)

    Werner, A.; Cassidenti, M.

    1984-01-01

    Copper electrodes replace graphite electrodes in many instances of electrical-discharge machining (EDM) of complex shapes. Copper electrodes wear longer and cause less contamination of EDM dielectric fluid than do graphite electrodes.

  18. An apparatus for studying electrical breakdown in liquid helium at 0.4 K and testing electrode materials for the neutron electric dipole moment experiment at the Spallation Neutron Source

    Science.gov (United States)

    Ito, T. M.; Ramsey, J. C.; Yao, W.; Beck, D. H.; Cianciolo, V.; Clayton, S. M.; Crawford, C.; Currie, S. A.; Filippone, B. W.; Griffith, W. C.; Makela, M.; Schmid, R.; Seidel, G. M.; Tang, Z.; Wagner, D.; Wei, W.; Williamson, S. E.

    2016-04-01

    We have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and ˜600 Torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of 1-2 cm between them, and a potential up to ±50 kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a wide range of pressures at 0.4 K. We also measured the current between two electrodes. Our initial results, I 5 × 1018 Ω cm. This lower bound is 5 times larger than the bound previously measured. We report the design, construction, and operational experience of the apparatus, as well as initial results.

  19. Microbial Communities and Electrochemical Performance of Titanium-Based Anodic Electrodes in a Microbial Fuel Cell

    NARCIS (Netherlands)

    Michaelidou, U.; Heijne, ter A.; Euverink, G.J.W.; Hamelers, H.V.M.; Stams, A.J.M.; Geelhoed, J.S.

    2011-01-01

    Four types of titanium (Ti)-based electrodes were tested in the same microbial fuel cell (MFC) anodic compartment. Their electrochemical performances and the dominant microbial communities of the electrode biofilms were compared. The electrodes were identical in shape, macroscopic surface area, and

  20. CHINA'S WORST OIL LEAK CLEARED EXPENSIVELY

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Eight days and nights of clean-up efforts after the worst oil leak ever in Chinese waters, the aftermath of a collision between two foreign ships happening at 9:35 pm on December 7 about 8 nautical miles away from the mouth of the Pearl River and near the Danjiang Island, have finally paid off. So far, hundreds of tons of waste oil and polluted water have been cleared up. A large area of oil spills has been cleaned thanks to the prompt and proper operation launched just two hours after the accident.

  1. A gap clearing kicker for Main Injector

    CERN Document Server

    Kourbanis, I; Biggs, J; Brown, B; Capista, D; Jensen, C C; Krafczyk, G E; Morris, D K; Scott, D; Seiya, K; Ward, S R; Wu, G; Yang, M -J

    2012-01-01

    Fermilab Main Injector has been operating at high Beam Power levels since 2008 when multi-batch slip stacking became operational. In order to maintain and increase the beam power levels the localized beam loss due to beam left over in the injection kicker gap during slip stacking needs to be addressed. A set of gap clearing kickers that kick any beam left in the injection gap to the beam abort have been built. The kickers were installed in the summer of 2009 and became operational in November of 2010. The kicker performance and its effect on the beam losses will be described.

  2. Novel Conductive Carbon Black and Polydimethlysiloxane ECG Electrode: A Comparison with Commercial Electrodes in Fresh, Chlorinated, and Salt Water.

    Science.gov (United States)

    Noh, Yeonsik; Bales, Justin R; Reyes, Bersain A; Molignano, Jennifer; Clement, Amanda L; Pins, George D; Florian, John P; Chon, Ki H

    2016-08-01

    In this study, we evaluated the performance of two novel conductive carbon black (CB) and polydimethlysiloxane (PDMS) bio-potential electrodes, with and without an integrated flexible copper mesh, against commercially available electrodes (Polar(®) textile, Silver-coated textile, and carbon rubber). The electrodes were tested in three types of water (fresh/unfiltered, chlorinated, and salt water). Our testing revealed that our CB/PDMS electrode with integrated copper mesh provided a high-fidelity ECG signal morphologies without any amplitude degradation in all of the types of water tested (N = 10). The non-meshed CB/PDMS electrodes were also subjected to a long-term durability test by the US Navy SCUBA divers during which the electrodes maintained ECG signal quality for a 6 h period of continuous use. The results of a material degradation analysis revealed the CB/PDMS composite material does not exhibit significant changes in physical integrity after prolonged exposure to the test conditions. The newly developed meshed CB/PDMS electrodes have the potential to be used in a wide variety of both dry and wet environments including the challenge of obtaining ECG signals in salt water environments.

  3. All-solid-state carbonate-selective electrode based on screen-printed carbon paste electrode

    Science.gov (United States)

    Li, Guang; Lyu, Xiaofeng; Wang, Zhan; Rong, Yuanzhen; Hu, Ruifen; Luo, Zhiyuan; Wang, You

    2017-02-01

    A novel disposable all-solid-state carbonate-selective electrode based on a screen-printed carbon paste electrode using poly(3-octylthiophene-2,5-diyl) (POT) as an ion-to-electron transducer has been developed. The POT was dropped onto the reaction area of the carbon paste electrode covered by the poly(vinyl chloride) (PVC) membrane, which contains N,N-Dioctyl-3α,12α-bis(4-trifluoroacetylbenzoyloxy)-5β-cholan-24-amide as a carbonate ionophore. The electrode showed a near-Nernstian slope of  -27.5 mV/decade with a detection limit of 3.6 * 10-5 mol l-1. Generally, the detection time was 30 s. Because these electrodes are fast, convenient and low in cost, they have the potential to be mass produced and used in on-site testing as disposable sensors. Furthermore, the repeatability, reproducibility and stability have been studied to evaluate the properties of the electrodes. Measurement of the carbonate was also conducted in a human blood solution and achieved good performance.

  4. Electrode models in electrical impedance tomography

    Institute of Scientific and Technical Information of China (English)

    WANG M.

    2005-01-01

    This paper presents different views on electrode modelling, which include electrode electrochemistry models for modelling the effects of electrode-electrolyte interface, electric field electrode models for modelling electrode geometry, and electrode models for modelling the effects of electrode common mode voltage and double layer capacitance. Taking the full electrode models into consideration .in electrical impedance tomography (EIT) will greatly help the optimised approach to a good solution and further understanding of the measurement principle.

  5. Malignant Clear Cell Hidradenoma of the Breast

    Science.gov (United States)

    Rahal, Ahmad K.; Reddy, Pavan S; Kallail, K. James

    2017-01-01

    A 58-year-old female had a mass in the right breast palpable beneath the areola. A mammogram revealed a 1.5-centimeter soft tissue density that was confirmed with a subsequent ultrasound. The patient underwent a core needle biopsy which was initially reported as a moderately differentiated invasive ductal carcinoma. Immunohistochemical analysis revealed negative staining for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER2), mammaglobin, and gross cystic disease fluid protein 15 (GCDFP-15). A wide local excision of the mass was performed. The pathology report stated the tumor had an infiltrative growth pattern with a desmoplastic stromal response with enhanced epithelial atypia consistent with malignant transformation of a nodular clear cell hidradenoma. Clear cell hidradenoma is a very rare tumor originating from the sweat gland and has a propensity for the face and extremities. The malignant variant of this tumor is extremely rare and has been reported to originate from the breast in few cases. This case represents the difficulty in diagnosing this tumor along with the radiographic and histologic features that can distinguish this malignancy from other entities.

  6. Amperometric determination of rutin on carbon paste electrodes

    Directory of Open Access Journals (Sweden)

    Pavla Macikova

    2010-12-01

    Full Text Available Three different carbon paste electrodes (i.e. unmodified, ironphthalocyanine and ionic liquid modified were tested to determinerutin by amperometry. The widest linear concentration range andlowest detection limit were obtained with unmodified carbon pasteelectrode.

  7. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1983-01-01

    Ion-Selective Electrode Reviews, Volume 5 is a collection of articles that covers ion-speciation. The book aims to present the advancements of the range and capabilities of selective ion-sensors. The topics covered in the selection are neutral carrier based ion-selective electrodes; reference electrodes and liquid junction effects in ion-selective electrode potentiometry; ion transfer across water/organic phase boundaries and analytical; and carbon substrate ion-selective electrodes. The text will be of great use to chemists and chemical engineers.

  8. Magnetohydrodynamic generator electrode

    Science.gov (United States)

    Marchant, David D.; Killpatrick, Don H.; Herman, Harold; Kuczen, Kenneth D.

    1979-01-01

    An improved electrode for use as a current collector in the channel of a magnetohydrodynamid (MHD) generator utilizes an elongated monolithic cap of dense refractory material compliantly mounted to the MHD channel frame for collecting the current. The cap has a central longitudinal channel which contains a first layer of porous refractory ceramic as a high-temperature current leadout from the cap and a second layer of resilient wire mesh in contact with the first layer as a low-temperature current leadout between the first layer and the frame. Also described is a monolithic ceramic insulator compliantly mounted to the frame parallel to the electrode by a plurality of flexible metal strips.

  9. Composite electrodes for lithium batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Hackney, S. A.; Johnson, C. S.; Kahaian, A. J.; Kepler, K. D.; Shao-Horn, Y.; Thackeray, M. M.; Vaughey, J. T.

    1999-02-03

    The stability of composite positive and negative electrodes for rechargeable lithium batteries is discussed. Positive electrodes with spinel-type structures that are derived from orthorhombic-LiMnO{sub 2} and layered-MnO{sub 2} are significantly more stable than standard spinel Li[Mn{sub 2}]O{sub 4} electrodes when cycled electrochemically over both the 4-V and 3-V plateaus in lithium cells. Transmission electron microscope data of cycled electrodes have indicated that a composite domain structure accounts for this greater electrochemical stability. The performance of composite Cu{sub x}Sn materials as alternative negative electrodes to amorphous SnO{sub x} electrodes for lithium-ion batteries is discussed in terms of the importance of the concentration of the electrochemically inactive copper component in the electrode.

  10. Coplanar Electrode Layout Optimized for Increased Sensitivity for Electrical Impedance Spectroscopy

    DEFF Research Database (Denmark)

    Clausen, Casper Hyttel; Skands, Gustav Erik; Bertelsen, Christian Vinther;

    2015-01-01

    This work describes an improvement in the layout of coplanar electrodes for electrical impedance spectroscopy. We have developed, fabricated, and tested an improved electrode layout, which improves the sensitivity of an impedance flow cytometry chip. The improved chip was experimentally tested...... and compared to a chip with a conventional electrode layout. The improved chip was able to discriminate 0.5 mu m beads from 1 mu m as opposed to the conventional chip. Furthermore, finite element modeling was used to simulate the improvements in electrical field density and uniformity between the electrodes...... of the new electrode layout. Good agreement was observed between the model and the obtained experimental results....

  11. An unusual case of clear cell meningioma

    Directory of Open Access Journals (Sweden)

    Deb Prabal

    2009-01-01

    Full Text Available Clear-cell meningioma (CCM is an uncommon, aggressive variant of meningioma, usually affecting younger females and having predilection for infratentorial locations. We present a rare case of recurrent supratentorial CCM in a 58-year-old male. Ten years back, he had an intra-axial tumor in the left occipital lobe, which was managed by surgical excision and radiotherapy. Currently, the patient presented with sudden severe headache along with speech and vision disturbances. Neuroimaging revealed an extra-axial parietooccipital tumor, with intratumoural bleed. Histopathology of both tumors showed features of CCM, immunopositive for epithelial membrane antigen (EMA and vimentin. This case illustrates multiple unusual features of a rare variant of meningioma in the form of affection of an adult age group, supratentorial location, recurrence, and intratumoral bleed. It also highlights the importance of incorporating immunohistochemistry in the diagnostic workup, to exclude CCM mimics, each having distinctive biological behavior, and prognostic outcome, and warranting different therapeutic protocols.

  12. The potential of clear-sky carbon dioxide satellite retrievals

    Directory of Open Access Journals (Sweden)

    R. R. Nelson

    2015-12-01

    Full Text Available Since the launch of the Greenhouse Gases Observing Satellite (GOSAT in 2009, retrieval algorithms designed to infer the column-averaged dry-air mole fraction of carbon dioxide (XCO2 from hyperspectral near-infrared observations of reflected sunlight have been greatly improved. They now generally include the scattering effects of clouds and aerosols, as early work found that absorption-only retrievals, which neglected these effects, often incurred unacceptably large errors, even for scenes with optically thin cloud or aerosol layers. However, these "full-physics" retrievals tend to be computationally expensive and may incur biases from trying to deduce the properties of clouds and aerosols when there are none present. Additionally, algorithms are now available that can quickly and effectively identify and remove most scenes in which cloud or aerosol scattering plays a significant role. In this work, we test the hypothesis that non-scattering, or "clear-sky", retrievals may perform as well as full-physics retrievals for sufficiently clear scenes. Clear-sky retrievals could potentially avoid errors and biases brought about by trying to infer properties of clouds and aerosols when none are present. Clear-sky retrievals are also desirable because they are orders of magnitude faster than full-physics retrievals. Here we use a simplified version of the Atmospheric Carbon Observations from Space (ACOS XCO2 retrieval algorithm that does not include the scattering and absorption effects of clouds or aerosols. It was found that for simulated Orbiting Carbon Observatory-2 (OCO-2 measurements, the clear-sky retrieval had errors comparable to those of the full-physics retrieval. For real GOSAT data, the clear-sky retrieval had nearly indistinguishable error characteristics over land, but roughly 30–60 % larger errors over ocean, depending on filtration level, compared to the full-physics retrieval. In general, the clear-sky retrieval had XCO2 root

  13. Clear-air radar observations of the atmospheric boundary layer

    Science.gov (United States)

    Ince, Turker

    2001-10-01

    This dissertation presents the design and operation of a high-resolution frequency-modulated continuous-wave (FM- CW) radar system to study the structure and dynamics of clear-air turbulence in the atmospheric boundary layer (ABL). This sensitive radar can image the vertical structure of the ABL with both high spatial and temporal resolutions, and provide both qualitative information about the morphology of clear-air structures and quantitative information on the intensity of fluctuations in refractive-index of air. The principles of operation and the hardware and data acquisition characteristics of the radar are described in the dissertation. In October 1999, the radar participated in the Cooperative Atmosphere-Surface Exchange Study (CASES'99) Experiment to characterize the temporal structure and evolution of the boundary-layer features in both convective and stable conditions. The observed structures include clear-air convection, boundary layer evolution, gravity waves, Kelvin-Helmholtz instabilities, stably stratified layers, and clear-air turbulence. Many of the S-band radar images also show high- reflectivity returns from Rayleigh scatterers such as insects. An adaptive median filtering technique based on local statistics has, therefore, been developed to discriminate between Bragg and Rayleigh scattering in clear-air radar observations. The filter is tested on radar observations of clear air convection with comparison to two commonly used image processing techniques. The dissertation also examines the statistical mean of the radar-measured C2n for clear-air convection, and compares it with the theoretical predictions. The study also shows that the inversion height, local thickness of the inversion layer, and the height of the elevated atmospheric layers can be estimated from the radar reflectivity measurements. In addition, comparisons to the radiosonde-based height estimates are made. To examine the temporal and spatial structure of C2n , the dissertation

  14. Study on the Characteristics of the Gas Switch Electrode Erosion

    Institute of Scientific and Technical Information of China (English)

    WANG Hu; CHANG Jia-sen; TONG Xin; ZHANG Qiao-gen

    2011-01-01

    Gas spark switch is one of the key parts in pulsed power technology.Electrode erosion has great influence on the switch performance and lifetime.In this paper,a field distortion gas switch is selected for the experiment and a great deal of discharging experiments have been conducted in different test conditions.The forming process of etch pit as well as its influencing factors is discussed briefly and surface roughness coefficient (SRC) of the electrode is put forward to evaluate the state of electrode erosion.Experimental results show that current peak plays an important role in electrode erosion when waveforms of discharge current are the same,and electric charge and oscillation frequency of discharge current also have great effect on the electrode erosion when waveforms of discharge current are different.With the increase of discharge times,SRC decreases slowly at first and then decreases quickly after three thousand of discharge times.

  15. Characterization of Transition-Metal Oxide Deposition on Carbon Electrodes of a Supercapacitor

    Directory of Open Access Journals (Sweden)

    Ying-Chung Chen

    2016-12-01

    Full Text Available In order to fabricate the composite electrodes of a supercapacitor, transition-metal oxide materials NiO and WO3 were deposited on carbon electrodes by electron beam evaporation. The influences of various transition-metal oxides, scan rates of cyclic voltammograms (CVs, and galvanostatic charge/discharge tests on the characteristics of supercapacitor were studied. The charge/discharge efficiency and the lifetime of the composite electrodes were also investigated. It was found that the composite electrodes exhibited more favorable capacitance properties than those of the carbon electrodes at high scan rates. The results revealed the promotion of the capacitance property of the supercapacitor with composite electrode and the improving of the decay property in capacitance at high scan rate. In addition, the charge/discharge efficiency is close to 100% after 5000 cycles, and the composite electrode retains strong adhesion between the electrode material and the substrate.

  16. Effect of annealing over optoelectronic properties of graphene based transparent electrodes

    Science.gov (United States)

    Yadav, Shriniwas; Kaur, Inderpreet

    2016-04-01

    Graphene, an atom-thick two dimensional graphitic material have led various fundamental breakthroughs in the field of science and technology. Due to their exceptional optical, physical and electrical properties, graphene based transparent electrodes have shown several applications in organic light emitting diodes, solar cells and thin film transistors. Here, we are presenting effect of annealing over optoelectronic properties of graphene based transparent electrodes. Graphene based transparent electrodes have been prepared by wet chemical approach over glass substrates. After fabrication, these electrodes tested for optical transmittance in visible region. Sheet resistance was measured using four probe method. Effect of thermal annealing at 200 °C was studied over optical and electrical performance of these electrodes. Optoelectronic performance was judged from ratio of direct current conductivity to optical conductivity (σdc/σopt) as a figure of merit for transparent conductors. The fabricated electrodes display good optical and electrical properties. Such electrodes can be alternatives for doped metal oxide based transparent electrodes.

  17. Variable selectivity of the Hitachi chemistry analyzer chloride ion-selective electrode toward interfering ions.

    Science.gov (United States)

    Wang, T; Diamandis, E P; Lane, A; Baines, A D

    1994-02-01

    Chloride measurements by ion-selective electrodes are vulnerable to interference by anions such as iodide, thiocyanate, nitrate, and bromide. We have found that the degree of interference of these anions on the Hitachi chemistry analyzer chloride electrode varies from electrode to electrode and this variation can even occur within the same lot of membrane. This variation is not dependent upon the length of time the cartridge has been in the analyzer because no correlation existed between the usage time and the electrode response to interfering ions. Neither is this variation due to the deterioration of the electrode because all electrodes tested had calibration slopes within the manufacturer's specification. Our study, however, showed that even after repeated exposure to a plasma sample containing 2 mM thiocyanate, the chloride electrode was still able to accurately measure the chloride in plasma without thiocyanate, thus confirming that a carryover effect does not exist from a previous thiocyanate-containing sample.

  18. Performance of dry electrode with bristle in recording EEG rhythms across brain state changes.

    Science.gov (United States)

    Kitoko, Vangu; Nguyen, Tuan N; Nguyen, Jordan S; Tran, Yvonne; Nguyen, Hung T

    2011-01-01

    In this paper we evaluate the physiological performance of a silver-silver chloride dry electrode with bristle (B-Electrode) in recording EEG data. For this purpose, we compare the performance of the bristle electrode in recording EEG data with the standard wet gold-plated cup electrode (G-Electrode) using two different brain state change tasks including resting condition with eyes-closed and performing mathematical task with eyes-open. Using a 2 channel recording device, eyes-closed command data were collected from each of 6 participants for a period of 20 sec and the same procedure was applied for the mathematical calculation task. These data were used for statistical and classification analyse. Although, B-electrode has shown a slightly higher performance compared with G-electrode in both tasks, but analyse did not reveal any significant differences between both electrodes in all six subjects tested.

  19. Gas sensor with multiple internal reference electrodes and sensing electrodes

    DEFF Research Database (Denmark)

    2016-01-01

    The invention relates to a potentiometric gas sensor, or potentiometric gas detection element, with multiple internal reference electrodes and multiple sensing electrodes for determining the concentrations of gas components in a gaseous mixture. The sensor for gas detection comprises: a solid...... electrolyte, at least two sensing electrodes (SEs) in solid contact with the electrolyte, and at least two internal reference electrodes (IREs) in solid contact with the electrolyte, wherein each IRE comprises a composite material, comprising a binary mixture of a metal and a metal oxide dispersed to form...

  20. Gold electrodes from recordable CDs

    Science.gov (United States)

    Angnes; Richter; Augelli; Kume

    2000-11-01

    Gold electrodes are widely used in electrochemistry and electroanalytical chemistry. The notable performance when used in stripping analysis of many ionic species and the extraordinary affinity of thio compounds for its surface make these electrodes very suitable for many applications. This paper reports a simple and novel way to construct gold electrodes (CDtrodes) using recordable CDs as the gold source. The nanometer thickness of the gold layer of recordable disks (50-100 nm) favors the construction of band nanoelectrodes with areas as small as 10(-6) cm2. The plane surface can be easily used for the construction of conventional-sized gold electrodes for batch or flow injection analysis or even to obtain electrodes as large as 100 cm2. The low price of commercial recordable CDs allows a "one way use". The evaluation and applicability of these electrodes in the form of nanoelectrodes, in batch and associated with flow cells, are illustrated in this paper.

  1. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  2. Electrodynamic Arrays Having Nanomaterial Electrodes

    Science.gov (United States)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  3. Jointed Holder For Welding Electrodes

    Science.gov (United States)

    Gilbert, Jeffrey L.

    1991-01-01

    Adjustable-angle holder enables use of standard straight electrode with custom-fabricated bent gas cup for welding in difficult-to-reach places. Electrode replaced easily, without removing cup, with aid of tool loosening miniature collet nut on holder. Consumes fewer electrodes for given amount of welding. Angle of holder continuously adjustable to fit angle of gas cup or geometry of part welded. Holder made double-jointed to accommodate gas cup having compound angles.

  4. Electrochemical Impedance of a Battery Electrode with Anisotropic Active Particles

    CERN Document Server

    Song, J

    2013-01-01

    Electrochemical impedance spectra for battery electrodes are usually interpreted using models that assume isotropic active particles, having uniform current density and symmetric diffusivities. While this can be reasonable for amorphous or polycrystalline materials with randomly oriented grains, modern electrode materials increasingly consist of highly anisotropic, single-crystalline, nanoparticles, with different impedance characteristics. In this paper, analytical expressions are derived for the impedance of anisotropic particles with tensorial diffusivities and orientation-dependent surface reaction rates and capacitances. The resulting impedance spectrum contains clear signatures of the anisotropic material properties and aspect ratio, as well as statistical variations in any of these parameters.

  5. A dry electrophysiology electrode using CNT arrays

    CERN Document Server

    Ruffini, G; Farres, E; Grau, C; Marco-Pallares, J; Mendoza, Eric; Ray, C; Silva, R; Dunne, Stephen; Farres, Esteve; Grau, Carles; Marco-Pallares, Josep; Mendoza, Ernest; Ray, Chris; Ruffini, Giulio; Silva, Ravi

    2006-01-01

    We describe the concept of a dry electrode sensor for biopotential measurement applications (ENOBIO) designed to eliminate the noise and inconvenience associated to the use of electrolytic gel. ENOBIO uses nanotechnology to remove gel-related noise, as well as maintaining a good contact impedance to minimise interference noise. The contact surface of the electrode will be covered with an array/forest of carbon nanotubes and will also be tested with an Ag/AgCl coating to provide ionic-electronic transduction. The nanotubes are to penetrate the outer layers of the skin, the Stratum Corneum, improving electrical contact. We discuss requirements, skin properties, nanotube penetration and transduction, noise sources, prototype design logic and biocompatibility. A future paper will report test results.

  6. MI Gap Clearing Kicker Magnet Design Review

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Chris; /Fermilab

    2008-10-01

    The kicker system requirements were originally conceived for the NOvA project. NOvA is a neutrino experiment located in Minnesota. To achieve the desired neutrino flux several upgrades are required to the accelerator complex. The Recycler will be used as a proton pre-injector for the Main Injector (MI). As the Recycler is the same size as the MI, it is possible to do a single turn fill ({approx}11 {micro}sec), minimizing the proton injection time in the MI cycle and maximizing the protons on target. The Recycler can then be filled with beam while the MI is ramping to extract beam to the target. To do this requires two new transfer lines. The existing Recycler injection line was designed for 10{pi} pbar beams, not the 20{pi} proton beams we anticipate from the Booster. The existing Recycler extraction line allows for proton injection through the MI, while we want direct injection from the Booster. These two lines will be decommissioned. The new injection line from the MI8 line into the Recycler will start at 848 and end with injection kickers at RR104. The new extraction line in the RR30 straight section will start with a new extraction kicker at RR232 and end with new MI injection kickers at MI308. Finally, to reduce beam loss activation in the enclosure, a new gap clearing kicker will be used to extract uncaptured beam created during the slip stack injection process down the existing dump line. It was suggested that the MI could benefit from this type of system immediately. This led to the early installation of the gap clearing system in the MI, followed by moving the system to Recycler during NOvA. The specifications also changed during this process. Initially the rise and fall time requirements were 38 ns and the field stability was {+-}1%. The 38 ns is based on having a gap of 2 RF buckets between injections. (There are 84 RF buckets that can be filled from the Booster for each injection, but 82 would be filled with beam. MI and Recycler contain 588 RF buckets

  7. Clear Channel Assessment in Integrated Medical Environments

    Directory of Open Access Journals (Sweden)

    Bin Zhen

    2008-03-01

    Full Text Available Complementary WLAN and WPAN technologies as well as other wireless technologies will play a fundamental role in the medical environments to support ubiquitous healthcare delivery. This paper investigates clear channel assessment (CCA and its impact on the coexistence of WLAN (IEEE 802.11 high rate direct sequence spread spectrum (HR/DSSS PHY and WPAN (IEEE 802.15.4b in the 2.4 GHz industrial, scientific, and medical (ISM band. We derived closed-form expressions of both energy-based CCA and feature-based CCA. We qualified unequal sensing abilities between them and termed this inequality asymmetric CCA, which is different from the traditional “hidden node” or “exposed node” issues in the homogeneous network. The energy-based CCA was considered in the considered integrated medical environment because the 2.4 GHz ISM band is too crowded to apply feature-based CCA. The WPAN is oversensitive to the 802.11 HR/DSSS signals and the WLAN is insensitive to the 802.15.4b signals. Choosing an optimal CCA threshold requires some prior knowledge of the underlying signals. In the integrated medical environment we considered here, energy-based CCA can effectively avoid possible packet collisions when they are close within the “heterogeneous exclusive CCA range” (HECR. However, when they are separated beyond the HECR, WPAN can still sense the 802.11 HR/DSSS signals, but WLAN loses its sense to the 802.15.4b signals. The asymmetric CCA leads to WPAN traffic in a position secondary to WLAN traffic.

  8. Clear Channel Assessment in Integrated Medical Environments

    Directory of Open Access Journals (Sweden)

    Hara Shinsuke

    2008-01-01

    Full Text Available Abstract Complementary WLAN and WPAN technologies as well as other wireless technologies will play a fundamental role in the medical environments to support ubiquitous healthcare delivery. This paper investigates clear channel assessment (CCA and its impact on the coexistence of WLAN (IEEE 802.11 high rate direct sequence spread spectrum (HR/DSSS PHY and WPAN (IEEE 802.15.4b in the 2.4 GHz industrial, scientific, and medical (ISM band. We derived closed-form expressions of both energy-based CCA and feature-based CCA. We qualified unequal sensing abilities between them and termed this inequality asymmetric CCA, which is different from the traditional "hidden node" or "exposed node" issues in the homogeneous network. The energy-based CCA was considered in the considered integrated medical environment because the 2.4 GHz ISM band is too crowded to apply feature-based CCA. The WPAN is oversensitive to the 802.11 HR/DSSS signals and the WLAN is insensitive to the 802.15.4b signals. Choosing an optimal CCA threshold requires some prior knowledge of the underlying signals. In the integrated medical environment we considered here, energy-based CCA can effectively avoid possible packet collisions when they are close within the "heterogeneous exclusive CCA range" (HECR. However, when they are separated beyond the HECR, WPAN can still sense the 802.11 HR/DSSS signals, but WLAN loses its sense to the 802.15.4b signals. The asymmetric CCA leads to WPAN traffic in a position secondary to WLAN traffic.

  9. Intakes of thorium while using thoriated tungsten electrodes for TIG welding.

    Science.gov (United States)

    Ludwig, T; Schwass, D; Seitz, G; Siekmann, H

    1999-10-01

    Thoriated electrodes are used in TIG welding. TIG welders, along with persons who grind thoriated electrodes and persons located near relevant welding and grinding sites, might be at risk of thorium intake. The isotopes of radiological relevance are 232Th, 230Th, and 228Th. The studies described in the literature do not provide a consistent picture of the actual hazards, and changes in European and German radiological protection laws have now made it necessary to determine the risks. To accomplish this, a field test was conducted under real working conditions in 26 different welding shops. The airborne activity generated through welding, and through grinding of electrodes, was measured using personal air samplers. Stationary samplers were also used. The filters' samples were evaluated by means of direct alpha spectrometry with proportional counting and by means of gamma spectrometry following neutron activation. The results clearly showed that considerable intake can occur during both alternating-current welding and electrode grinding, if no suction systems are used. The range of 232Th intakes to welders were estimated from 0.1 Bq y(-1) to 144 Bq y(-1) during welding and from 0.02 Bq y(-1) to 30.2 Bq y(-1) during grinding. In 6 of the 26 cases the recent annual limit on intake derived from the most recent ICRP publications was exceeded--in the worst case it was exceeded by a factor of 10--if it is assumed that the persons studied were not exposed workers (not routinely monitored for radiation exposure). When the significantly more restrictive German limits are applied, the amounts by which the limits were exceeded were even greater. Because many qualified welders have very long careers, the risks can thus be considerable. The paper also discusses parameters that influence exposure, and it presents a catalogue of recommended measures for dosage reduction.

  10. Coated carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng; Wen, Jian; Chen, Jinghua; Huang, Zhongping; Wang, Dezhi

    2008-10-28

    The present invention provides conductive carbon nanotube (CNT) electrode materials comprising aligned CNT substrates coated with an electrically conducting polymer, and the fabrication of electrodes for use in high performance electrical energy storage devices. In particular, the present invention provides conductive CNTs electrode material whose electrical properties render them especially suitable for use in high efficiency rechargeable batteries. The present invention also provides methods for obtaining surface modified conductive CNT electrode materials comprising an array of individual linear, aligned CNTs having a uniform surface coating of an electrically conductive polymer such as polypyrrole, and their use in electrical energy storage devices.

  11. Ion-selective electrode reviews

    CERN Document Server

    Thomas, J D R

    1982-01-01

    Ion-Selective Electrode Reviews, Volume 3, provides a review of articles on ion-selective electrodes (ISEs). The volume begins with an article on methods based on titration procedures for surfactant analysis, which have been developed for discrete batch operation and for continuous AutoAnalyser use. Separate chapters deal with detection limits of ion-selective electrodes; the possibility of using inorganic ion-exchange materials as ion-sensors; and the effect of solvent on potentials of cells with ion-selective electrodes. Also included is a chapter on advances in calibration procedures, the d

  12. Electrodes for Semiconductor Gas Sensors.

    Science.gov (United States)

    Lee, Sung Pil

    2017-03-25

    The electrodes of semiconductor gas sensors are important in characterizing sensors based on their sensitivity, selectivity, reversibility, response time, and long-term stability. The types and materials of electrodes used for semiconductor gas sensors are analyzed. In addition, the effect of interfacial zones and surface states of electrode-semiconductor interfaces on their characteristics is studied. This study describes that the gas interaction mechanism of the electrode-semiconductor interfaces should take into account the interfacial zone, surface states, image force, and tunneling effect.

  13. EFFECTS OF TEMPERATURE AND CONTAMINATION ON MPCMS ELECTRODES IN 241-AY-101 AND 241-AN-107 TANK WASTE SIMULANTS

    Energy Technology Data Exchange (ETDEWEB)

    CATO DM; DAHL MM; PHILO GL; EDGEMON GL; BELL DR.JLS; MOORE CG

    2010-03-26

    This report documents the results of tests designed to characterize the relationship between temperature and the measured potential of electrodes installed on multi-probe corrosion monitoring systems in waste tanks. This report also documents the results of tests designed to demonstrate the impact of liquid in-leakage into electrode bodies as well as the contamination of primary reference electrodes by diffusion through the electrode tip.

  14. When a Cleared Rape Is Not Cleared: A Multilevel Study of Arrest and Exceptional Clearance.

    Science.gov (United States)

    Walfield, Scott M

    2016-05-01

    As rape remains one of the most underreported and least likely to be cleared of the violent crimes, it is of paramount importance to understand the factors associated with the likelihood of a case being cleared by law enforcement. This study uses data from the National Incident-Based Reporting System (NIBRS) and the Law Enforcement Management and Administrative Statistics (LEMAS), and a multilevel modeling approach to examine the relationship between victim, offender, incident, and police department characteristics contrasting the two types of clearance: arrest and exceptional clearance. The latter occurs due to reasons outside of law enforcement's control and despite being considered cleared, the offender is not arrested, charged, nor turned over for prosecution. Of the 16,231 cleared rapes in 238 departments, nearly half (47%) results in exceptional clearance when the victim refuses to cooperate or when prosecution is declined. Incident-level variables have a greater effect on the likelihood of exceptional clearance than victim and offender variables. The department explained a nontrivial amount of variation in the dependent variable, as 37% of the variance in type of clearance was between-department variation. Implications for future research on exceptional clearance and NIBRS are discussed.

  15. Clear cell renal cell tumors: Not all that is "clear" is cancer.

    Science.gov (United States)

    Williamson, Sean R; Cheng, Liang

    2016-07-01

    Continued improvement of our understanding of the clinical, histologic, and genetic features of renal cell tumors has progressively evolved renal tumor classification, revealing an expanding array of distinct tumor types with different implications for prognosis, patient counseling, and treatment. Although clear cell renal cell carcinoma is unequivocally the most common adult renal tumor, there is growing evidence that some "clear cell" renal neoplasms, such as exemplified by multilocular cystic clear cell renal neoplasm of low malignant potential (formerly multilocular cystic renal cell carcinoma), do not have the same potential for insidious progression and metastasis, warranting reclassification as low malignant potential tumors or benign neoplasms. Still other novel tumor types such as clear cell papillary renal cell carcinoma have been more recently recognized, which similarly have shown a conspicuous absence of aggressive behavior to date, suggesting that these too may be recategorized as noncancerous or may be premalignant neoplasms. This importance for prognosis is increasingly significant in the modern era, in which renal masses are increasingly found incidentally by imaging techniques at a small tumor size, raising consideration for less aggressive management options guided by renal mass biopsy diagnosis, including imaging surveillance, tumor ablation, or partial nephrectomy.

  16. MICROSTRUCTURE AND PROPERTIES OF DEEP CROGENIC TREATMENT ELECTRODES FOR SPOT WELDING HOT DIP GALVANIZED STEEL

    Institute of Scientific and Technical Information of China (English)

    Wu Zhisheng; Liu Cuirong; Wang Jiuhai; Shan Ping; Hu Shengsun; Lian Jinrui

    2005-01-01

    The microstructure and elements distribution of the deep cryogenic treatment electrodes and non-cryogenic treatment electrodes for spot welding hot dip galvanized steel are observed by a scanning electrical microscope. The grain sizes, the resistivity and the hardness of the electrodes before and after deep cryogenic treatment are measured by X-ray diffraction, the DC double arms bridge and the Brinell hardness testing unit respectively. The spot welding process performance of hot dip galvanized steel plate is tested and the relationship between microstructure and physical properties of deep cryogenic treatment electrodes is analyzed. The experimental results show that deep cryogenic treatment makes Cr, Zr in deep cryogenic treatment electrodes emanate dispersedly and makes the grain of deep cryogenic treatment electrodes smaller than non-cryogenic treatment ones so that the electrical conductivity and the thermal conductivity of deep cryogenic treatment electrodes are improved very much, which make spot welding process performance of the hot dip galvanized steel be improved.

  17. Field Emission Dark Current of Technical Metallic Electrodes

    CERN Document Server

    Le Pimpec, F

    2006-01-01

    In the framework of the Low Emittance Gun (LEG) project, high gradient acceleration of a low emittance electron beam will be necessary. In order to achieve this acceleration a -500 kV, 250 ns FWHM, pulse will be applied in between two electrodes. Those electrodes should sustain the pulsed field without arcing, must not outgass and must not emit electrons. Ion back bombardment, and dark current will be damageable to the electron source as well as for the low emittance beam. Electrodes of commercially available OFE copper, aluminium, stainless steel, titanium and molybdenum were tested following different procedures including plasma glow discharge cleaning.

  18. Avalanche analysis from multi-electrode ensemble recordings in cat, monkey and human cerebral cortex during wakefulness and sleep.

    Directory of Open Access Journals (Sweden)

    Nima eDehghani

    2012-08-01

    Full Text Available Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical states in the awake brain remains controversial. Here, we compared avalanche analyses performed on different in vivo preparations during wakefulness, slow-wave sleep and REM sleep, using high-density electrode arrays in cat motor cortex (96 electrodes, monkey motor cortex and premotor cortex and human temporal cortex (96 electrodes in epileptic patients. In neuronal avalanches defined from units (up to 160 single units, the size of avalanches never clearly scaled as power-law, but rather scaled exponentially or displayed intermediate scaling. We also analyzed the dynamics of local field potentials (LFPs and in particular LFP negative peaks (nLFPs among the different electrodes (up to 96 sites in temporal cortex or up to 128 sites in adjacent motor and pre-motor cortices. In this case, the avalanches defined from nLFPs displayed power-law scaling in double logarithmic representations, as reported previously in monkey. However, avalanche defined as positive LFP (pLFP peaks, which are less directly related to neuronal firing, also displayed apparent power-law scaling. Closer examination of this scaling using the more reliable cumulative distribution function (CDF and other rigorous statistical measures, did not confirm power-law scaling. The same pattern was seen for cats, monkey and human, as well as for different brain states of wakefulness and sleep. We also tested other alternative distributions. Multiple exponential fitting yielded optimal fits of the avalanche dynamics with bi-exponential distributions. Collectively, these results show no clear evidence for power-law scaling or self-organized critical states in the awake and sleeping brain of mammals, from cat to man.

  19. Carbon nanotube electrodes for effective interfacing with retinal tissue.

    Science.gov (United States)

    Shoval, Asaf; Adams, Christopher; David-Pur, Moshe; Shein, Mark; Hanein, Yael; Sernagor, Evelyne

    2009-01-01

    We have investigated the use of carbon nanotube coated microelectrodes as an interface material for retinal recording and stimulation applications. Test devices were micro-fabricated and consisted of 60, 30 mum diameter electrodes at spacing of 200 mum. These electrodes were coated via chemical vapor deposition of carbon nanotubes, resulting in conducting, three dimensional surfaces with a high interfacial area. These attributes are important both for the quality of the cell-surface coupling as well as for electro-chemical interfacing efficiency. The entire chip was packaged to fit a commercial multielectrode recording and stimulation system. Electrical recordings of spontaneous spikes from whole-mount neonatal mouse retinas were consistently obtained minutes after retinas were placed over the electrodes, exhibiting typical bursting and propagating waves. Most importantly, the signals obtained with carbon nanotube electrodes have exceptionally high signal to noise ratio, reaching values as high as 75. Moreover, spikes are marked by a conspicuous gradual increase in amplitude recorded over a period of minutes to hours, suggesting improvement in cell-electrode coupling. This phenomenon is not observed in conventional commercial electrodes. Electrical stimulation using carbon nanotube electrodes was also achieved. We attribute the superior performances of the carbon nanotube electrodes to their three dimensional nature and the strong neuro-carbon nanotube affinity. The results presented here show the great potential of carbon nanotube electrodes for retinal interfacing applications. Specifically, our results demonstrate a route to achieve a reduction of the electrode down to few micrometers in order to achieve high efficacy local stimulation needed in retinal prosthetic devices.

  20. Point Electrode Studies of the Solid Electrolyte-Electrode Interface

    DEFF Research Database (Denmark)

    Jacobsen, Torben

    \\parbox[t]{7.3cm}{Strong anodic activation due to computer communication error.} It is seen that as long as the electrode is kept at the equilibrium potential, the capacity pr.\\,unit area is constant, indicating a stable reaction zone. Polarising the electrode a decrease in this ratio is observed. Although......In the development of new electrode materials for high temperature Solid Oxide Fuel Cells methods are needed for the electrochemical evaluation of the catalytic properties of the materials. A major problem in the comparison of materials is how to determine the geometry and the effective length...... of the active reaction zone, the triple phase boundary. One way of solving this is by the application of point electrodes where the electrode-electrolyte contact is assumed to be circular with a radius calculated from the high frequency impedance. The perimeter is the taken as the length of the reaction zone...

  1. Development of a Compact Wireless Laplacian Electrode Module for Electromyograms and Its Human Interface Applications

    Directory of Open Access Journals (Sweden)

    Akira Ichikawa

    2013-02-01

    Full Text Available In this study, we developed a compact wireless Laplacian electrode module for electromyograms (EMGs. One of the advantages of the Laplacian electrode configuration is that EMGs obtained with it are expected to be sensitive to the firing of the muscle directly beneath the measurement site. The performance of the developed electrode module was investigated in two human interface applications: character-input interface and detection of finger movement during finger Braille typing. In the former application, the electrode module was combined with an EMG-mouse click converter circuit. In the latter, four electrode modules were used for detection of finger movements during finger Braille typing. Investigation on the character-input interface indicated that characters could be input stably by contraction of (a the masseter, (b trapezius, (c anterior tibialis and (d flexor carpi ulnaris muscles. This wide applicability is desirable when the interface is applied to persons with physical disabilities because the disability differs one to another. The investigation also demonstrated that the electrode module can work properly without any skin preparation. Finger movement detection experiments showed that each finger movement was more clearly detectable when comparing to EMGs recorded with conventional electrodes, suggesting that the Laplacian electrode module is more suitable for detecting the timing of finger movement during typing. This could be because the Laplacian configuration enables us to record EMGs just beneath the electrode. These results demonstrate the advantages of the Laplacian electrode module.

  2. Graphite Based Electrode for ECG Monitoring: Evaluation under Freshwater and Saltwater Conditions

    Directory of Open Access Journals (Sweden)

    Tharoeun Thap

    2016-04-01

    Full Text Available We proposed new electrodes that are applicable for electrocardiogram (ECG monitoring under freshwater- and saltwater-immersion conditions. Our proposed electrodes are made of graphite pencil lead (GPL, a general-purpose writing pencil. We have fabricated two types of electrode: a pencil lead solid type (PLS electrode and a pencil lead powder type (PLP electrode. In order to assess the qualities of the PLS and PLP electrodes, we compared their performance with that of a commercial Ag/AgCl electrode, under a total of seven different conditions: dry, freshwater immersion with/without movement, post-freshwater wet condition, saltwater immersion with/without movement, and post-saltwater wet condition. In both dry and post-freshwater wet conditions, all ECG-recorded PQRST waves were clearly discernible, with all types of electrodes, Ag/AgCl, PLS, and PLP. On the other hand, under the freshwater- and saltwater-immersion conditions with/without movement, as well as post-saltwater wet conditions, we found that the proposed PLS and PLP electrodes provided better ECG waveform quality, with significant statistical differences compared with the quality provided by Ag/AgCl electrodes.

  3. Efficacy of transgene expression in porcine skin as a function of electrode choice

    DEFF Research Database (Denmark)

    Gotholf, Anita; Mahmood, Faisad; Dagnæs-Hansen, Frederik;

    2011-01-01

    , have mainly been performed in rodents and the body of evidence on electrode choice and optimal pulsing conditions is limited. We therefore tested plate and needle electrodes in vivo in porcine skin, which resembles human skin in structure. The luciferase (pCMV-Luc) gene was injected intradermally......, our data support that needle electrodes should be used in human clinical studies of gene electrotransfer to skin for improved expression....... and subsequently electroporated. Simultaneously, studies with gene electrotransfer to porcine skin using plasmids coding for green fluorescent protein (GFP) and betagalactosidase were performed. Interestingly, we found needle electrodes to be more efficient than plate electrodes (p

  4. Estimation of clear sky hourly global solar radiation in Iraq

    Energy Technology Data Exchange (ETDEWEB)

    Al-Jumaily, Kais J.; Al-Zuhairi, Munya F.; Mahdi, Zahraa S. [Department of Atmospheric Sciences, College of Science, Al-Mustansiriyah University, Baghdad (Iraq)

    2012-07-01

    The availability of hourly solar radiation data is very important for applications utilizing solar energy and for climate and environmental aspects. The aim of this work is to use a simple model for estimating hourly global solar radiation under clear sky condition in Iraq. Calculations were compared with measurements obtained from local station in Baghdad city and from Meteosat satellite data for different locations in Iraq. The statistical test methods of the mean bias error (MBE), root mean square error (RMSE) and t-test were used to evaluate the performance of the model. Results indicated that a fairly good agreement exists between calculated and measured values for all locations in Iraq. Since the model is independent of any meteorological variable, it would be of a practical use for rural areas where no meteorological data are available.

  5. Light addressable gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Waqas

    2011-07-01

    The main objective carried out in this dissertation was to fabricate Light Amplified Potentiometric sensors (LAPS) based upon the semiconductor nanoparticles (quantum dots) instead of its bulk form. Quantum dots (QDs) were opted for this device fabrication because of their superior fluorescent, electric and catalytic properties. Also in comparison to their bulk counterparts they will make device small, light weighted and power consumption is much lower. QDs were immobilized on a Au substrate via 1,4 benzene dithiol (BDT) molecule. Initially a self-assembled monolayer (SAM) of BDT was established on Au substrate. Because of SAM, the conductivity of Au substrate decreased dramatically. Furthermore QDs were anchored with the help of BDT molecule on Au substrate. When QDs immobilized on Au substrate (QD/Au) via BDT molecule were irradiated with UV-visible light, electron-hole pairs were generated in QDs. The surface defect states in QDs trapped the excited electrons and long lived electron-hole pairs were formed. By the application of an appropriate bias potential on Au substrate the electrons could be supplied or extracted from the QDs via tunneling through BDT. Thus a cathodic or anodic current could be observed depending upon bias potential under illumination. However without light illumination the QD/Au electrode remained an insulator. To improve the device different modifications were made, including different substrates (Au evaporated on glass, Au evaporated on mica sheets and Au sputtered on SiO{sub 2}/Si) and different dithiol molecules (capped and uncapped biphenyl 4,4' dithiol and capped and uncapped 4,4' dimercaptostilbenes) were tried. Also different QD immobilization techniques (normal incubation, spin coating, layer by layer assembly (LbL) of polyelectrolytes and heat immobilization) were employed. This device was able to detect electrochemically different analytes depending upon the QDs incorporated. For example CdS QDs were able to detect 4

  6. Carbon Nanotube Electrodes for Effective Interfacing with Retinal Tissue

    OpenAIRE

    Shoval, Asaf; Adams, Christopher; David-Pur, Moshe; Shein, Mark; Hanein, Yael; Sernagor, Evelyne

    2009-01-01

    We have investigated the use of carbon nanotube coated microelectrodes as an interface material for retinal recording and stimulation applications. Test devices were micro-fabricated and consisted of 60, 30 μm diameter electrodes at spacing of 200 μm. These electrodes were coated via chemical vapor deposition of carbon nanotubes, resulting in conducting, three dimensional surfaces with a high interfacial area. These attributes are important both for the quality of the cell-surface coupling as...

  7. Erosion on spark plug electrodes; Funkenerosion an Zuendkerzenelektroden

    Energy Technology Data Exchange (ETDEWEB)

    Rager, J.

    2006-07-01

    Durability of spark plugs is mainly determined by spark gap widening, caused by electrode wear. Knowledge about the erosion mechanisms of spark plug materials is of fundamental interest for the development of materials with a high resistance against electrode erosion. It is therefore crucial to identify those parameters which significantly influence the erosion behaviour of a material. In this work, a reliable and reproducible testing method is presented which produces and characterizes electrode wear under well-defined conditions and which is capable of altering parameters specifically. Endurance tests were carried out to study the dependence of the wear behaviour of pure nickel and platinum on the electrode temperature, gas, electrode gap, electrode diameter, atmospheric pressure, and partial pressure of oxygen. It was shown that erosion under nitrogen is negligible, irrespective of the material. This disproves all common mechanism discussed in the literature explaining material loss of spark plug electrodes. Based on this observation and the variation of the mentioned parameters a new erosion model was deduced. This relies on an oxidation of the electrode material and describes the erosion of nickel and platinum separately. For nickel, electrode wear is caused by the removal of an oxide layer by the spark. In the case of platinum, material loss occurs due to the plasma-assisted formation and subsequent evaporation of volatile oxides in the cathode spot. On the basis of this mechanism a new composite material was developed whose erosion resistance is superior to pure platinum. Oxidation resistant metal oxide particles were added to a platinum matrix, thus leading to a higher erosion resistance of the composite. However, this can be decreased by a side reaction, the separation of oxygen from the metal oxides, which effectively assists the oxidation of the matrix. This reaction can be suppressed by using highly stable oxides, characterized by a large negative Gibbs

  8. ELECTROCHEMISTRY OF FUEL CELL ELECTRODES.

    Science.gov (United States)

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

  9. Making EDM Electrodes By Stereolithography

    Science.gov (United States)

    Barlas, Philip A.

    1988-01-01

    Stereolithography is computer-aided manufacturing technique. Used to make models and molds of electrodes for electrical-discharge machining (EDM). Eliminates intermediate steps in fabrication of plastic model of object used in making EDM electrode to manufacture object or mold for object.

  10. The In-cell iR Compensation Using a Four-electrode System

    Institute of Scientific and Technical Information of China (English)

    Xiang Qin LIN; Liang Dong FENG

    2006-01-01

    A novel idea of in-cell iR compensation was proposed by using a four-electrode electrochemical system, which was consisted of two working electrodes, one reference electrode (RE)and one auxiliary electrode (AE). One of the two working electrodes was called the auxiliary working electrode (AWE), which was directly connected to the ground. Another working electrode was used as a regular working electrode (WE) for electrochemical testing. The reference electrode was set in a frit close to the AWE for potential sampling. The other electrodes, WE, RE and AE, were connected to a conventional potentiostat of three-electrode system for electrochemical measurements. A linear narrow electrochemical cell was designed for setting AE at one end and AWE with RE at another end,and setting WE in between AE and AWE. In this way, a positive feedback potential was generated at the working electrode from the solution resistance and the current flow in the solution. An formal iR compensation over 100%, as high as 500%, had been achieved without potential oscillation. The electrochemical cell design, the principle of the in-cell iR compensation, and the preliminary voltammetric characterization by using the redox reaction of ferrocyanide anions were reported.

  11. Use of epoxy-embedded electrodes to integrate electrochemical detection with microchip-based analysis systems.

    Science.gov (United States)

    Selimovic, Asmira; Johnson, Alicia S; Kiss, István Z; Martin, R Scott

    2011-04-01

    A new method of fabricating electrodes for microchip devices that involves the use of Teflon molds and a commercially available epoxy to embed electrodes of various sizes and compositions is described. The resulting epoxy base can be polished to generate a fresh electrode and sealed against poly(dimethylsiloxane) (PDMS)-based fluidic structures. Microchip-based flow injection analysis was used to characterize the epoxy-embedded electrodes. It was shown that gold electrodes can be amalgamated with liquid mercury and the resulting mercury/gold electrode is used to selectively detect glutathione from lysed red blood cells. The ability to encapsulate multiple electrode materials of differing compositions enabled the integration of microchip electrophoresis with electrochemical detection. Finally, a unique feature of this approach is that the electrode connection is made from the bottom of the epoxy base. This enables the creation of three-dimensional gold pillar electrodes (65 μm in diameter and 27 μm in height) that can be integrated within a fluidic network. As compared with the use of a flat electrode of a similar diameter, the use of the pillar electrode led to improvements in both the sensitivity (72.1 pA/μM for the pillar versus 4.2 pA/μM for the flat electrode) and limit of detection (20 nM for the pillar versus 600 nM for the flat electrode), with catechol being the test analyte. These epoxy-embedded electrodes hold promise for the creation of inexpensive microfluidic devices that can be used to electrochemically detect biologically important analytes in a manner where the electrodes can be polished and a fresh electrode surface is generated as desired.

  12. Differences in regeneration between hurricane damaged and clear-cut mangrove stands 25 years after clearing

    OpenAIRE

    Ferwerda, J.G.; Ketner, P.; McGuiness, K.A.

    2007-01-01

    The effect of human disturbance on mangrove forest may be substantially different from the effects of natural disturbances. This paper describes differences in vegetation composition and structure of five vegetation types in two mangrove areas near Darwin, Australia, 25 years after disturbance. The vegetation in clear-felled forest showed more adult Avicennia marina than in the hurricane-affected forest, and a virtual absence of A. marina juveniles and saplings. This indicates that A. marina ...

  13. Electrode for a lithium cell

    Science.gov (United States)

    Thackeray, Michael M.; Vaughey, John T.; Dees, Dennis W.

    2008-10-14

    This invention relates to a positive electrode for an electrochemical cell or battery, and to an electrochemical cell or battery; the invention relates more specifically to a positive electrode for a non-aqueous lithium cell or battery when the electrode is used therein. The positive electrode includes a composite metal oxide containing AgV.sub.3O.sub.8 as one component and one or more other components consisting of LiV.sub.3O.sub.8, Ag.sub.2V.sub.4O.sub.11, MnO.sub.2, CF.sub.x, AgF or Ag.sub.2O to increase the energy density of the cell, optionally in the presence of silver powder and/or silver foil to assist in current collection at the electrode and to improve the power capability of the cell or battery.

  14. Composite electrode/electrolyte structure

    Science.gov (United States)

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

    2004-01-27

    Provided is an electrode fabricated from highly electronically conductive materials such as metals, metal alloys, or electronically conductive ceramics. The electronic conductivity of the electrode substrate is maximized. Onto this electrode in the green state, a green ionic (e.g., electrolyte) film is deposited and the assembly is co-fired at a temperature suitable to fully densify the film while the substrate retains porosity. Subsequently, a catalytic material is added to the electrode structure by infiltration of a metal salt and subsequent low temperature firing. 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.

  15. Evaluation of Niobium as Candidate Electrode Material for DC High Voltage Photoelectron Guns

    Science.gov (United States)

    BastaniNejad, M.; Mohamed, Abdullah; Elmustafa, A. A.; Adderley, P.; Clark, J.; Covert, S.; Hansknecht, J.; Hernandez-Garcia, C.; Poelker, M.; Mammei, R.; Surles-Law, K.; Williams, P.

    2012-01-01

    The field emission characteristics of niobium electrodes were compared to those of stainless steel electrodes using a DC high voltage field emission test apparatus. A total of eight electrodes were evaluated: two 304 stainless steel electrodes polished to mirror-like finish with diamond grit and six niobium electrodes (two single-crystal, two large-grain, and two fine-grain) that were chemically polished using a buffered-chemical acid solution. Upon the first application of high voltage, the best large-grain and single-crystal niobium electrodes performed better than the best stainless steel electrodes, exhibiting less field emission at comparable voltage and field strength. In all cases, field emission from electrodes (stainless steel and/or niobium) could be significantly reduced and sometimes completely eliminated, by introducing krypton gas into the vacuum chamber while the electrode was biased at high voltage. Of all the electrodes tested, a large-grain niobium electrode performed the best, exhibiting no measurable field emission (< 10 pA) at 225 kV with 20 mm cathode/anode gap, corresponding to a field strength of 18:7 MV/m.

  16. Study of the electrochemical properties of a transition metallic ions modified electrode in acidic VOSO4 solution

    Institute of Scientific and Technical Information of China (English)

    WANG Wenhong; WANG Xindong

    2007-01-01

    Graphite material was used as the electrode for an all-vanadium redox flow battery, and the electrode was modified by transition metallic ions to enhance its electrochemical behavior. An porous graphite composite electrode has high specific surface area and high current density. The electrode modified by transition metallic ions has improved catalysis behavior that can catalyze the V(Ⅱ)-V(Ⅴ) redox reaction showed by cyclic voltammograms. This article studied the impedance of the modified electrode by electrochemical impedance spectroscopy (EIS), and approved that the electrode modified by Co2+ and Mn2+ has a lower charge transfer resistance than the non-modified electrode. The effect of average particle size distribution is at lower frequencies that the slope of Warburg impedance is reduced by large particle size distribution. The voltage efficiency of the Co2+ modified electrode test cell is 81.5%, which is higher than that of the non-modified electrode.

  17. Coaxial fiber supercapacitor using all-carbon material electrodes.

    Science.gov (United States)

    Le, Viet Thong; Kim, Heetae; Ghosh, Arunabha; Kim, Jaesu; Chang, Jian; Vu, Quoc An; Pham, Duy Tho; Lee, Ju-Hyuck; Kim, Sang-Woo; Lee, Young Hee

    2013-07-23

    We report a coaxial fiber supercapacitor, which consists of carbon microfiber bundles coated with multiwalled carbon nanotubes as a core electrode and carbon nanofiber paper as an outer electrode. The ratio of electrode volumes was determined by a half-cell test of each electrode. The capacitance reached 6.3 mF cm(-1) (86.8 mF cm(-2)) at a core electrode diameter of 230 μm and the measured energy density was 0.7 μWh cm(-1) (9.8 μWh cm(-2)) at a power density of 13.7 μW cm(-1) (189.4 μW cm(-2)), which were much higher than the previous reports. The change in the cyclic voltammetry characteristics was negligible at 180° bending, with excellent cycling performance. The high capacitance, high energy density, and power density of the coaxial fiber supercapacitor are attributed to not only high effective surface area due to its coaxial structure and bundle of the core electrode, but also all-carbon materials electrodes which have high conductivity. Our coaxial fiber supercapacitor can promote the development of textile electronics in near future.

  18. Textile Electrodes for EEG Recording — A Pilot Study

    Directory of Open Access Journals (Sweden)

    Johan Löfhede

    2012-12-01

    Full Text Available The overall aim of our research is to develop a monitoring system for neonatal intensive care units. Long-term EEG monitoring in newborns require that the electrodes don’t harm the sensitive skin of the baby, an especially relevant feature for premature babies. Our approach to EEG monitoring is based on several electrodes distributed over the head of the baby, and since the weight of the head always will be on some of them, any type of hard electrode will inevitably cause a pressure-point that can irritate the skin. Therefore, we propose the use of soft conductive textiles as EEG electrodes, primarily for neonates, but also for other kinds of unobtrusive long-term monitoring. In this paper we have tested two types of textile electrodes on five healthy adults and compared them to standard high quality electrodes. The acquired signals were compared with respect to morphology, frequency distribution, spectral coherence, correlation and power line interference sensitivity, and the signals were found to be similar in most respects. The good measurement performance exhibited by the textile electrodes indicates that they are feasible candidates for EEG recording, opening the door for long-term EEG monitoring applications.

  19. Flexible Graphene Electrodes for Prolonged Dynamic ECG Monitoring

    Directory of Open Access Journals (Sweden)

    Cunguang Lou

    2016-11-01

    Full Text Available This paper describes the development of a graphene-based dry flexible electrocardiography (ECG electrode and a portable wireless ECG measurement system. First, graphene films on polyethylene terephthalate (PET substrates and graphene paper were used to construct the ECG electrode. Then, a graphene textile was synthesized for the fabrication of a wearable ECG monitoring system. The structure and the electrical properties of the graphene electrodes were evaluated using Raman spectroscopy, scanning electron microscopy (SEM, and alternating current impedance spectroscopy. ECG signals were then collected from healthy subjects using the developed graphene electrode and portable measurement system. The results show that the graphene electrode was able to acquire the typical characteristics and features of human ECG signals with a high signal-to-noise (SNR ratio in different states of motion. A week-long continuous wearability test showed no degradation in the ECG signal quality over time. The graphene-based flexible electrode demonstrates comfortability, good biocompatibility, and high electrophysiological detection sensitivity. The graphene electrode also combines the potential for use in long-term wearable dynamic cardiac activity monitoring systems with convenience and comfort for use in home health care of elderly and high-risk adults.

  20. STS-69 Clears the tower (side view)

    Science.gov (United States)

    1995-01-01

    A pack of astronauts that run under the banner Dog Crew II heads for the stars. Liftoff of the Space Shuttle Endeavour from Launch Pad 39A occurred at 11:09:00.052 a.m. EDT, Sept. 7, 1995. 'Every dog has its day and today is your day,' KSC Orbiter Test Conductor Roger Gillette pledged to STS-69 Mission Commander David M. Walker, Pilot Kenneth D. Cockrell, Payload Commander James S. Voss and Mission Specialists Michael L. Gernhardt and James H. Newman prior to launch. The STS-69 astronaut crew developed a strong sense of comaraderie as they went through their flight training, and dubbed themselves the Dog Crew II to carry on a tradition that arose during an earlier Shuttle flight -- STS-53 -- to which both Voss and Walker were assigned. Each crew member adopted a dog-theme name: Walker is Red Dog; Cockrell, Cujo; Voss, Dogface; Newman, Pluto; and Gernhardt, the only space rookie, Underdog. A special patch, featuring a bulldog in a doghouse shaped like the Space Shuttle, was designed for the astronauts and other flight team members to wear. The Dog Crew II is embarking on an 11-day multifaceted mission featuring two free-flying scientific research spacecraft as well as a host of experiments in both the payload bay and the middeck. Also scheduled is an extravehicular activity, or spacewalk.

  1. CLEARS An Education and Research Tool for Computational Semantics

    CERN Document Server

    Milward, D; Maier, Hans J; Pinkal, M; Milward, David; Konrad, Karsten; Maier, Holger; Pinkal, Manfred

    1996-01-01

    The CLEARS (Computational Linguistics Education and Research for Semantics) tool provides a graphical interface allowing interactive construction of semantic representations in a variety of different formalisms, and using several construction methods. CLEARS was developed as part of the FraCaS project which was designed to encourage convergence between different semantic formalisms, such as Montague-Grammar, DRT, and Situation Semantics. The CLEARS system is freely available on the WWW from http://coli.uni-sb.de/~clears/clears.html

  2. Preset Electrodes for Electrical-Discharge Machining

    Science.gov (United States)

    Coker, Bill E.

    1987-01-01

    New electrode holder for electrical-discharge machining (EDM) provides for repeatable loading and setting of many electrodes. New holder is rotating-index tool carrying six, eight, or more electrodes. Before use, all electrodes set with aid of ring surrounding tool, and locked in position with screws. When electrode replaced, EDM operator pulls spring-loaded pin on tool so it rotates about center pin. Fresh electrode then rotated into position against workpiece.

  3. Do collective actions clear common air?

    Energy Technology Data Exchange (ETDEWEB)

    Aakvik, A.; Tjoetta, S. [Univ. of Bergen (Norway). Dept. of Economics

    2007-07-01

    ;participants' and 'non-participants', ie. those that did and those that did not ratify the specific protocol, respectively. They use a difference-in-difference estimator which focuses on difference in emission before and after signing a specific protocol and compares it to this difference for non-participating countries. Difference-in-difference estimation methods rely on many annual data and hence this will induce serial correlations in the variables. Overlooking this may introduce biased estimate of the standard errors. To overcome this bias the authors follow Bertrand et. al. (2003), and compute the difference-in-difference estimates for a great number of randomly generated placebo protocols. They use this empirical distribution of placebo effects to test estimated effects.

  4. Determination of Thallium(I by Hybrid Mesoporous Silica (SBA-15 Modified Electrode

    Directory of Open Access Journals (Sweden)

    Geeta Rani

    2016-01-01

    Full Text Available Chemically modified mesoporous silica material (SBA-15 was used for the construction of Tl(I selective carbon paste electrode. The best response was found with the electrode containing 10% modifier as electrode material. The electrode has a lower detection limit of 6.0 × 10−9 M in a working concentration range of 1.0 × 10−8–1.0 × 10−1 M. The selectivity coefficient calculated by match potential method (MPM shows the high selectivity of electrode towards Tl(I over other tested ions. The electrode was successfully applied as an indicator electrode for the titration of 0.01 M TlNO3 solution with standards EDTA solution and for sequential titration of mixture of different anions.

  5. Carbon nanotube electrodes for effective interfacing with retinal tissue

    Directory of Open Access Journals (Sweden)

    Asaf Shoval

    2009-04-01

    Full Text Available We have investigated the use of carbon nanotube microelectrodes as an interface material for retinal recording and stimulation applications. Test devices were micro-fabricated and consisted of 60 pristine 30 um electrodes coated with chemical vapor deposited carbon nanotubes, resulting in conducting, three dimensional surfaces with a high effective interfacial area. These attributes are important both for the quality of the cell-surface coupling as well as for electro-chemical interfacing efficiency. The entire chip was packaged to fit a commercial multielectrode recording and stimulation system. Electrical recordings of spontaneous spikes from whole-mount neonatal mouse retinas were consistently obtained minutes after retinas were placed over the electrodes, exhibiting typical bursting and propagating waves. Most importantly, the signals obtained with carbon nanotube electrodes have exceptionally high signal to noise ratio, reaching values as high as 75. Moreover, spikes are marked by a conspicuous gradual increase in amplitude recorded over a period of minutes to hours, suggesting improvement in cell-electrode coupling. This phenomenon is not observed in conventional commercial electrodes. Electrical stimulation using carbon nanotube electrodes was also achieved. We attribute the superior performances of the carbon nanotube electrodes to their three dimensional nature and the strong neuro-carbon nanotube affinity. The results presented here show the great potential of carbon nanotube electrodes for retinal interfacing applications. Specifically, our results demonstrate a route to achieve a reduction in the electrode size down to few micrometers in order to achieve high efficacy local stimulation needed in retinal prosthetic devices.

  6. Four point probe structures with buried and surface electrodes for the electrical characterization of ultrathin conducting films

    NARCIS (Netherlands)

    Groenland, A.W.; Wolters, R.A.M.; Kovalgin, A.Y.; Schmitz, J.

    2012-01-01

    Test structures for the electrical characterization of ultrathin conductive films are presented based on electrodes on which the ultrathin film is deposited. Two different designs are discussed: a novel design with buried electrodes and a conventional design with electrodes at the surface. This work

  7. Printed metal back electrodes for R2R fabricated polymer solar cells studied using the LBIC technique

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Søndergaard, Roar; Jørgensen, Mikkel

    2011-01-01

    employed. Organic solvent based, UV-curable and water based silver inks were tested. Both grid electrodes and full electrodes were employed and it was shown via the grid electrode that the organic solvent based ink adversely affects the device performance under the printed metal whereas both the UV...

  8. Statistical functions and relevant correlation coefficients of clearness index

    Science.gov (United States)

    Pavanello, Diego; Zaaiman, Willem; Colli, Alessandra; Heiser, John; Smith, Scott

    2015-08-01

    This article presents a statistical analysis of the sky conditions, during years from 2010 to 2012, for three different locations: the Joint Research Centre site in Ispra (Italy, European Solar Test Installation - ESTI laboratories), the site of National Renewable Energy Laboratory in Golden (Colorado, USA) and the site of Brookhaven National Laboratories in Upton (New York, USA). The key parameter is the clearness index kT, a dimensionless expression of the global irradiance impinging upon a horizontal surface at a given instant of time. In the first part, the sky conditions are characterized using daily averages, giving a general overview of the three sites. In the second part the analysis is performed using data sets with a short-term resolution of 1 sample per minute, demonstrating remarkable properties of the statistical distributions of the clearness index, reinforced by a proof using fuzzy logic methods. Successively some time-dependent correlations between different meteorological variables are presented in terms of Pearson and Spearman correlation coefficients, and introducing a new one.

  9. X-ray microtomographic confirmation of the reliability of CBCT in identifying the scalar location of cochlear implant electrode after round window insertion.

    Science.gov (United States)

    Zou, Jing; Hannula, Markus; Lehto, Kalle; Feng, Hao; Lähelmä, Jaakko; Aula, Antti S; Hyttinen, Jari; Pyykkö, Ilmari

    2015-08-01

    Cone-beam computed tomography (CBCT) plays a key role in cochlear implantation in both planning implantation before surgery and quality control during surgery due to the high spatial resolution and convenience of application in the operation theater. We recently designed a novel, highresolution cone-beam acquisition system that has been tested in temporal bones with cochlear implantation to identify the scalar localization of the electrode arrays. The current study aimed to verify the reliability of the experimental CBCT set-up using high-resolution in vitro X-ray microtomography (μCT) imaging as a reference. Nine human temporal bones were studied by inserting a straight electrode of a cochlear implant using the round window approach followed by sequential imaging using experimental CBCT and μCT with and without 1% iodine as the contrast agent. In the CBCT images, the electrodes were located in the scala tympani and near the lateral wall in all temporal bones. In the μCT images, the cochlear fine structures, including Reissner's membrane, stria vascularis, spiral ligament, basilar membrane, spiral limbus, osseous spiral lamina, and Rosenthal's canal that hosts the spiral ganglion cells, were clearly delineated; the electrode array avoided the lateral wall of the scala tympani in the hook region and then ran along the lateral wall of the scala tympani without any exception, a feature that was also detected in a temporal bone with ruptures in the basilar and Reissner's membranes. In conclusion, the current in vitro μCT imaging system produced high-quality images that could demonstrate the fine cochlear structures faithfully and verify the reliability of a novel experimental CBCT set-up aimed for clinical application in identifying the scalar localization of the electrode array. The straight electrode is safe for cochlear structures with low risk of translocation and is suitable for atraumatic implantation, although a large gap between the contacts and the

  10. Capacitance enhancement via electrode patterning

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Tuan A.; Striolo, Alberto, E-mail: a.striolo@ucl.ac.uk [School of Chemical, Biological and Materials Engineering, The University of Oklahoma, Norman, Oklahoma 73019 (United States); Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)

    2013-11-28

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  11. Capacitance enhancement via electrode patterning

    Science.gov (United States)

    Ho, Tuan A.; Striolo, Alberto

    2013-11-01

    The necessity of increasing the energy density in electric double layer capacitors to meet current demand is fueling fundamental and applied research alike. We report here molecular dynamics simulation results for aqueous electrolytes near model electrodes. Particular focus is on the effect of electrode patterning on the structure of interfacial electrolytes, and on the potential drop between the solid electrodes and the bulk electrolytes. The latter is estimated by numerically integrating the Poisson equation using the charge densities due to water and ions accumulated near the interface as input. We considered uniform and patterned electrodes, both positively and negatively charged. The uniformly charged electrodes are modeled as graphite. The patterned ones are obtained by removing carbon atoms from the top-most graphene layer, yielding nanoscopic squares and stripes patterns. For simplicity, the patterned electrodes are effectively simulated as insulators (the charge remains localized on the top-most layer of carbon atoms). Our simulations show that the patterns alter the structure of water and the accumulation of ions at the liquid-solid interfaces. Using aqueous NaCl solutions, we found that while the capacitance calculated for three positively charged electrodes did not change much, that calculated for the negatively charged electrodes significantly increased upon patterning. We find that both water structure and orientation, as well as ion accumulation affect the capacitance. As electrode patterning affects differently water structure and ion accumulation, it might be possible to observe ion-specific effects. These results could be useful for advancing our understanding of electric double layer capacitors, capacitive desalination processes, as well as of fundamental interfacial electrolytes properties.

  12. Ferrocene-functionalized graphene electrode for biosensing applications

    Energy Technology Data Exchange (ETDEWEB)

    Rabti, Amal [Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193 Barcelona (Spain); Université de Tunis El–Manar, Faculté des Sciences de Tunis, Laboratoire de Chimie Analytique et Electrochimie (LR99ES15), Campus universitaire de Tunis El–Manar, 2092, Tunis (Tunisia); Mayorga-Martinez, Carmen C.; Baptista-Pires, Luis [Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193 Barcelona (Spain); Raouafi, Noureddine, E-mail: n.raouafi@fst.rnu.tn [Université de Tunis El–Manar, Faculté des Sciences de Tunis, Laboratoire de Chimie Analytique et Electrochimie (LR99ES15), Campus universitaire de Tunis El–Manar, 2092, Tunis (Tunisia); Merkoçi, Arben, E-mail: arben.merkoci@icn2.cat [Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology, Campus UAB, Bellaterra, 08193 Barcelona (Spain); ICREA, Barcelona, Catalonia (Spain)

    2016-07-05

    A novel ferrocene-functionalized reduced graphene oxide (rGO)-based electrode is proposed. It was fabricated by the drop casting of ferrocene-functionalized graphene onto polyester substrate as the working electrode integrated within screen-printed reference and counter electrodes. The ferrocene-functionalized rGO has been fully characterized using FTIR, XPS, contact angle measurements, SEM and TEM microscopy, and cyclic voltammetry. The XPS and EDX analysis showed the presence of Fe element related to the introduced ferrocene groups, which is confirmed by a clear CV signal at ca. 0.25 V vs. Ag/AgCl (0.1 KCl). Mediated redox catalysis of H{sub 2}O{sub 2} and bio-functionalization with glucose oxidase for glucose detection were achieved by the bioelectrode providing a proof for potential biosensing applications. - Graphical abstract: An easy-to-prepare standalone graphene electrode was obtained by the drop-casting ferrocene-functionalized rGO on PET polymer. This electrode can be used as an enzymeless electrochemical sensor for the detection of hydrogen peroxide or as an amperometric enzyme-based biosensor for sensitive glucose detection. - Highlights: • A novel ferrocene-functionalized reduced graphene oxide based electrode. • Ease of preparation by drop-casting of Fc-modified graphene and chitosan mixture. • Well-defined and exploitable ferrocene CV signal for sensing purposes. • Sensitive enzymeless detection of hydrogen peroxide at low potentials. • Enzymatic Sensitive detection of glucose on GOx-modified graphene electrode.

  13. Surface analysis of new chlorpromazinium plastic membrane electrodes.

    Science.gov (United States)

    Al-Shatti, L A; Marafie, H M; Shoukry, A F

    2008-01-22

    New chlorpromazinium (Cp) plastic membrane electrodes of the conventional type were constructed and characterized. They are based on incorporation of Cp-reineckate (CpRn) ion pair, Cp-phosphotungstate (Cp3PT), or Cp-phosphomolybdate (Cp3PM) ion associate into poly(vinyl chloride) membrane. The electrodes exhibited calibration graph slopes of 49.83, 52.87, and 61.30 mV/Cp concentration decade over life spans of 1, 5, and 3 days, respectively. All electrodes proved to be selective for Cp and have been applied to the assay of a pharmaceutical preparation. Energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS), as well as scanning electron microscopy (SEM) showed that the limitation of the lifetime of the electrodes is attributed to leaching of the ion exchanger from the membrane into the test solution in addition to deformation of the surface.

  14. Electrode materials for microbial fuel cells: nanomaterial approach

    KAUST Repository

    Mustakeem, Mustakeem

    2015-11-05

    Microbial fuel cell (MFC) technology has the potential to become a major renewable energy resource by degrading organic pollutants in wastewater. The performance of MFC directly depends on the kinetics of the electrode reactions within the fuel cell, with the performance of the electrodes heavily influenced by the materials they are made from. A wide range of materials have been tested to improve the performance of MFCs. In the past decade, carbon-based nanomaterials have emerged as promising materials for both anode and cathode construction. Composite materials have also shown to have the potential to become materials of choice for electrode manufacture. Various transition metal oxides have been investigated as alternatives to conventional expensive metals like platinum for oxygen reduction reaction. In this review, different carbon-based nanomaterials and composite materials are discussed for their potential use as MFC electrodes.

  15. Kinetic Studies on Ni-YSZ Composite Electrodes

    DEFF Research Database (Denmark)

    Njodzefon, Jean-Claude; Hjelm, Johan; Graves, Christopher R.

    2015-01-01

    . Furthermore, when polarized, the cell heats up due to joule heating of the electrolyte but also the electrodes either heat or cool due to exothermic oxidation or endothermic reduction of gaseous reactant species. Kinetic investigation of SOC electrodes independent of the above effects thus requires...... transfer at the reaction sites gas conversion at the flow fields, and ohmic drop across the electrolyte. Since these processes occur in both electrodes and some of them with overlapping characteristic frequencies, it is particularly challenging to isolate and characterize a particular mechanism...... compositions using the same instrument. The tests are carried out in a single gas atmosphere with maximum flow rate of 6 L/h. Results and Discussion Current density vs working electrode overpotential curves recorded in the temperature range 800 – 650°C in a 50/50 H2/H2O fuel mixture are displayed in figure 1(a...

  16. Synthesis, Structure and Reactivity of Molecules Attached to Electrode Surfaces.

    Science.gov (United States)

    2014-09-26

    Structure and Reactivity of Molecules Attached to Electrode Surfaces", AFOSR #81-0149 III. REPORTING PERIOD: April 15, 1981 through April 14, 1985 IV...Adsorption .... ............... 17 9. Effect of Surface Roughness on Adsorbate Orientation and Reactivity . 20 10. Ordered/ Disordered Packing in Chemisorbed... reactivity only when present in the edge-pendant orientation. Clearly, molecular orientation (i.e., mode of +. .4 o,, -12- attachment to the surface) is a

  17. All-clear for gourmets: truffles not radioactive

    Science.gov (United States)

    Büntgen, U.; Jäggi, M.; Stobbe, U.; Tegel, W.; Sproll, L.; Eikenberg, J.; Egli, S.

    2016-02-01

    Although ranging among the most expensive gourmet foods, it remains unclear whether Burgundy truffles (Tuber aestivum) accumulate radioactivity at a harmful level comparable to other fungal species. Here, we measure the 137Cs in 82 T. aestivum fruit bodies from Switzerland, Germany, France, Italy, and Hungary. All tested specimens reveal insignificant radiocaesium concentrations, thus providing an all-clear for many truffle hunters and cultivators in large parts of Europe as well as the subsequent chain of dealers and customers from around the world. Our results are particularly relevant in the light of ongoing efforts to cultivate Burgundy truffles, as well as the fact that several forest ecosystems are still highly contaminated with 137Cs, for which mushrooms are one of the main pathways to human diets.

  18. Renal Clear Cell Sarcoma - Anaplastic Variant: A Rare Entity.

    Science.gov (United States)

    Walke, Vaishali Atmaram; Shende, Nitin Y; Kumbhalkar, D T

    2017-01-01

    Clear Cell Sarcoma of Kidney (CCSK) is known for its morphologic diversity, aggressive behaviour, tendency to recur and metastasis to bone. Amongst the various morphologic subtypes, anaplastic CCSK is associated with worse prognosis. Here, we report a case of this rare variant of CCSK. A five-year-old boy presented with history of lump and pain in abdomen since one week. The Computed Tomography (CT) scan revealed a large mass occupying the middle and inferior pole of right kidney. The clinical impression was Wilms tumour. Nephrectomy specimen was received and the diagnosis of CCSK anaplastic variant was offered only after excluding the differentials and after performing ancillary tests such as Immunohistochemistry (IHC). Thus, this case emphasizes the diagnostic challenges on morphology and the essential role of IHC in arriving at a definitive diagnosis, because failure to do so may deprive the child from optimal treatment.

  19. Nanowire-decorated microscale metallic electrodes

    DEFF Research Database (Denmark)

    Vlad, A.; Mátéfi-Tempfli, M.; Antohe, V.A.;

    2008-01-01

    of lithographically defined metallic microelectrodes. The anodization of the aluminum permits electroplating only on top of the metallic electrodes, leading to the nanowire patterns having the same shape as the underlying metallic tracks. The variation in the fabricated structures between the patterned and non......The fabrication of metallic nanowire patterns within anodic alumina oxide (AAO) membranes on top of continuous conducting substrates are discussed. The fabrication protocol is based on the realization of nanowire patterns using supported nanoporous alumina templates (SNAT) prepared on top......-patterned substrates can be interpreted in terms of different behavior during anodization. The improved quality of fabricated nanowire patterns is clearly demonstrated by the SEM imaging and the uniform growth of nanowires inside the alumina template is observed without any significant height variation....

  20. Sub-micrometer-sized graphite as a conducting and catalytic counter electrode for dye-sensitized solar cells.

    Science.gov (United States)

    Veerappan, Ganapathy; Bojan, Karunagaran; Rhee, Shi-Woo

    2011-03-01

    Sub-micrometer-sized colloidal graphite (CG) was tested as a conducting electrode to replace transparent conducting oxide (TCO) electrodes and as a catalytic material to replace platinum (Pt) for I(3)(-) reduction in dye-sensitized solar cell (DSSC). CG paste was used to make a film via the doctor-blade process. The 9 μm thick CG film showed a lower resistivity (7 Ω/◻) than the widely used fluorine-doped tin oxide TCO (8-15 Ω/◻). The catalytic activity of this graphite film was measured and compared with the corresponding properties of Pt. Cyclic voltammetry and electrochemical impedance spectroscopy studies clearly showed a decrease in the charge transfer resistance with the increase in the thickness of the graphite layer from 3 to 9 μm. Under 1 sun illumination (100 mW cm(-2), AM 1.5), DSSCs with submicrometer-sized graphite as a catalyst on fluorine-doped tin oxide TCO showed an energy conversion efficiency greater than 6.0%, comparable to the conversion efficiency of Pt. DSSCs with a graphite counter electrode (CE) on TCO-free bare glass showed an energy conversion efficiency greater than 5.0%, which demonstrated that the graphite layer could be used both as a conducting layer and as a catalytic layer.

  1. Thin film fuel cell electrodes.

    Science.gov (United States)

    Asher, W. J.; Batzold, J. S.

    1972-01-01

    Earlier work shows that fuel cell electrodes prepared by sputtering thin films of platinum on porous vycor substrates avoid diffusion limitations even at high current densities. The presented study shows that the specific activity of sputtered platinum is not unusually high. Performance limitations are found to be controlled by physical processes, even at low loadings. Catalyst activity is strongly influenced by platinum sputtering parameters, which seemingly change the surface area of the catalyst layer. The use of porous nickel as a substrate shows that pore size of the substrate is an important parameter. It is noted that electrode performance increases with increasing loading for catalyst layers up to two microns thick, thus showing the physical properties of the sputtered layer to be different from platinum foil. Electrode performance is also sensitive to changing differential pressure across the electrode. The application of sputtered catalyst layers to fuel cell matrices for the purpose of obtaining thin total cells appears feasible.

  2. Measurements of Electrode Skin Impedances using Carbon Rubber Electrodes - First Results

    Science.gov (United States)

    Kaufmann, Steffen; Ardelt, Gunther; Ryschka, Martin

    2013-04-01

    Non-invasive bioimpedance measurement as a tool in biomedical engineering and life sciences allows conclusions about condition and composition of living tissue. For interfacing the electronic conduction of the instrumentation and the ionic conduction of the tissue, electrodes are needed. A crucial point is the uncertainty arising from the unknown, time-varying and current density depend Electrode Skin Impedance (ESI). This work presents ESI measurements using carbon rubber electrodes on different human test subjects. The measurements for this work are carried out by employing a high accuracy Bioimpedance Measurement System (BMS) developed by the authors group, which is based on a Field Programmable Gate Array (FPGA) System on Chip (SoC). The system is able to measure magnitude and phase of complex impedances using a two- or four-electrode setup, with excitation currents from 60 μA to 5 mA in a frequency range from about 10 kHz to 300 kHz. Achieved overall measurement uncertainties are below 1%.

  3. Colloidal silver nanoparticles modified electrode and its application to the electroanalysis of Cytochrome c

    Energy Technology Data Exchange (ETDEWEB)

    Lin Li [Department of Chemistry, Wenzhou Medical College, Wenzhou 325035 (China)], E-mail: linliwz@21cn.com; Qiu Peihong [Department of Chemistry, Wenzhou Medical College, Wenzhou 325035 (China); Cao Xuni; Jin Litong [Department of Chemistry, East China Normal University, Shanghai 200062 (China)

    2008-06-30

    A colloidal silver nanoparticles (CSNs) chemically modified electrode was prepared and its application to the electroanalysis of Cytochrome c (Cyt. c) was studied. The CSNs were prepared by reduction of AgNO{sub 3} with NaBH{sub 4}, and were stabilized by oleate. They could be efficiently immobilized on the surface of a silver electrode. The result showed that the CSNs could clearly enhance the electron transfer process between Cyt. c and the electrode compared with bulk silver electrode. Linear sweep voltammetric measurement of Cyt. c at the chemical modified electrode indicated that the oxidative peak current of Cyt. c was linear to its concentration ranging from 8.0 nmol L{sup -1} to 3.0 {mu}mol L{sup -1} with the calculated detection limit was about 2.6 nmol L{sup -1}. The direct electrochemistry of Cyt. c was also studied by cyclic voltammetry.

  4. Solubility determination from clear points upon solvent addition

    NARCIS (Netherlands)

    Reus, M.A.; Heijden, A.E.D.M. van der; Horst, J.H. ter

    2015-01-01

    A method is described for determining the solubility of multicomponent crystalline compounds from clear points upon sample dilution at a constant temperature. Clear points are established by continuously adding a solvent mixture to a suspension of known composition until a clear solution appears. Fo

  5. Stimulation and recording electrodes for neural prostheses

    CERN Document Server

    Pour Aryan, Naser; Rothermel, Albrecht

    2015-01-01

    This book provides readers with basic principles of the electrochemistry of the electrodes used in modern, implantable neural prostheses. The authors discuss the boundaries and conditions in which the electrodes continue to function properly for long time spans, which are required when designing neural stimulator devices for long-term in vivo applications. Two kinds of electrode materials, titanium nitride and iridium are discussed extensively, both qualitatively and quantitatively. The influence of the counter electrode on the safety margins and electrode lifetime in a two electrode system is explained. Electrode modeling is handled in a final chapter.

  6. Implanted electrodes for multi-month EEG.

    Science.gov (United States)

    Jochum, Thomas; Engdahl, Susannah; Kolls, Brad J; Wolf, Patrick

    2014-01-01

    An implanted electroencephalogram (EEG) recorder would help diagnose infrequent seizure-like events. A proof-of-concept study quantified the electrical characteristics of the electrodes planned for the proposed recorder. The electrodes were implanted in an ovine model for eight weeks. Electrode impedance was less than 800 Ohms throughout the study. A frequency-domain determination of sedation performed similarly for surface versus implanted electrodes throughout the study. The time-domain correlation between an implanted electrode and a surface electrode was almost as high as between two surface electrodes (0.86 versus 0.92). EEG-certified clinicians judged that the implanted electrode quality was adequate to excellent and that the implanted electrodes provided the same clinical information as surface electrodes except for a noticeable amplitude difference. No significant issues were found that would stop development of the EEG recorder.

  7. Protrusion of the Rod Electrode in the Electrospinning Process

    Directory of Open Access Journals (Sweden)

    Jan Valtera

    2015-01-01

    Full Text Available The paper focuses on the influence of the protrusion of the rod electrode on critical voltage in the DC electrospinning process. On the testing and industrial DC electrospinning devices, electrodes of any kind are extended towards the counter electrode. This provides the maximal, that is, supercritical, electric field intensity on the spinning-electrode orifice that is found to be higher than on the other supplementary parts. The principal study and experiments with basic apparatus were carried out and presented by Taylor in 1966. This study is focused on the arrangement closely related to the design of the real electrospinning device with respect to the safety and technological aspects. Results of the carried out experiments of the rod spinning-electrode are compared with the electrostatic simulation and analytical calculation. The presented effect of the electrode protrusion on the potential difference and the critical field strength introduces valuable information for the designers of electrospinning machines as well as for the setting up of the optimal technological parameters for producing modern nonwoven textile products.

  8. Recording and assessment of evoked potentials with electrode arrays.

    Science.gov (United States)

    Miljković, N; Malešević, N; Kojić, V; Bijelić, G; Keller, T; Popović, D B

    2015-09-01

    In order to optimize procedure for the assessment of evoked potentials and to provide visualization of the flow of action potentials along the motor systems, we introduced array electrodes for stimulation and recording and developed software for the analysis of the recordings. The system uses a stimulator connected to an electrode array for the generation of evoked potentials, an electrode array connected to the amplifier, A/D converter and computer for the recording of evoked potentials, and a dedicated software application. The method has been tested for the assessment of the H-reflex on the triceps surae muscle in six healthy humans. The electrode array with 16 pads was positioned over the posterior aspect of the thigh, while the recording electrode array with 16 pads was positioned over the triceps surae muscle. The stimulator activated all the pads of the stimulation electrode array asynchronously, while the signals were recorded continuously at all the recording sites. The results are topography maps (spatial distribution of evoked potentials) and matrices (spatial visualization of nerve excitability). The software allows the automatic selection of the lowest stimulation intensity to achieve maximal H-reflex amplitude and selection of the recording/stimulation pads according to predefined criteria. The analysis of results shows that the method provides rich information compared with the conventional recording of the H-reflex with regard the spatial distribution.

  9. Characterization of All Solid State Hydrogen Ion Selective Electrode Based on PVC-SR Hybrid Membranes

    Directory of Open Access Journals (Sweden)

    Yoon-Bo Shim

    2003-06-01

    Full Text Available Hydrogen ion selective membranes formulated with 3140 RTV silicone rubber (SR in PVC were studied to extend the life time of solid state ion sensors through improved membrane adhesion. All solid state hydrogen ion selective electrodes were prepared by incorporation of tridodecyl amine (TDDA as an ionophore, potassium tetrakis[3.5-bis(p-chlorophenylborate (KTpClPB as a lipophilic additive, bis(2-ethylhexyladipate (DOA as a plasticizer. Their linear dynamic range was pH 2.0-11.0 and showed the near Nernstian slope of 55.1±0.2 mV/pH (r=0.999. The ifluences from alkali and alkaline earth metal ions were studied for the response of the final ISE membrane composition. Impedance spectroscopic data showed that the resistance was increased by increasing SR content in PVC. Brewster Angle Microscopy (BAM image showed clear differences according to the SR compositions in PVC. Life time of the all solid state membrane electrode was extended to about 2 months by preparing the membrane with PVC and SR. The standard reference material from NIST (2181 HEPES Free acid and 2182 NaHEPESate was tested for the ISE and it gave good result.

  10. Extraction electrode geometry for a calutron

    Science.gov (United States)

    Veach, A.M.; Bell, W.A. Jr.

    1975-09-23

    This patent relates to an improved geometry for the extraction electrode and the ground electrode utilized in the operation of a calutron. The improved electrodes are constructed in a partial-picture-frame fashion with the slits of both electrodes formed by two tungsten elongated rods. Additional parallel spaced-apart rods in each electrode are used to establish equipotential surfaces over the rest of the front of the ion source. (auth)

  11. Dielectrophoretic capture of low abundance cell population using thick electrodes

    Science.gov (United States)

    Marchalot, Julien; Chateaux, Jean-François; Faivre, Magalie; Mertani, Hichem C.; Ferrigno, Rosaria; Deman, Anne-Laure

    2015-01-01

    Enrichment of rare cell populations such as Circulating Tumor Cells (CTCs) is a critical step before performing analysis. This paper presents a polymeric microfluidic device with integrated thick Carbon-PolyDimethylSiloxane composite (C-PDMS) electrodes designed to carry out dielectrophoretic (DEP) trapping of low abundance biological cells. Such conductive composite material presents advantages over metallic structures. Indeed, as it combines properties of both the matrix and doping particles, C-PDMS allows the easy and fast integration of conductive microstructures using a soft-lithography approach while preserving O2 plasma bonding properties of PDMS substrate and avoiding a cumbersome alignment procedure. Here, we first performed numerical simulations to demonstrate the advantage of such thick C-PDMS electrodes over a coplanar electrode configuration. It is well established that dielectrophoretic force (FDEP) decreases quickly as the distance from the electrode surface increases resulting in coplanar configuration to a low trapping efficiency at high flow rate. Here, we showed quantitatively that by using electrodes as thick as a microchannel height, it is possible to extend the DEP force influence in the whole volume of the channel compared to coplanar electrode configuration and maintaining high trapping efficiency while increasing the throughput. This model was then used to numerically optimize a thick C-PDMS electrode configuration in terms of trapping efficiency. Then, optimized microfluidic configurations were fabricated and tested at various flow rates for the trapping of MDA-MB-231 breast cancer cell line. We reached trapping efficiencies of 97% at 20 μl/h and 78.7% at 80 μl/h, for 100 μm thick electrodes. Finally, we applied our device to the separation and localized trapping of CTCs (MDA-MB-231) from a red blood cells sample (concentration ratio of 1:10). PMID:26392836

  12. CNT/PDMS composite flexible dry electrodes for long-term ECG monitoring.

    Science.gov (United States)

    Jung, Ha-Chul; Moon, Jin-Hee; Baek, Dong-Hyun; Lee, Jae-Hee; Choi, Yoon-Young; Hong, Joung-Sook; Lee, Sang-Hoon

    2012-05-01

    We fabricated a carbon nanotube (CNT)/ polydimethylsiloxane (PDMS) composite-based dry ECG electrode that can be readily connected to conventional ECG devices, and showed its long-term wearable monitoring capability and robustness to motion and sweat. While the dispersion of CNTs in PDMS is challenging, we optimized the process to disperse untreated CNTs within PDMS by mechanical force only. The electrical and mechanical characteristics of the CNT/PDMS electrode were tested according to the concentration of CNTs and its thickness. The performances of ECG electrodes were evaluated by using 36 types of electrodes which were fabricated with different concentrations of CNTs, and with a differing diameter and thickness. The ECG signals were obtained by using electrodes of diverse sizes to observe the effects of motion and sweat, and the proposed electrode was shown to be robust to both factors. The CNT concentration and diameter of the electrodes were critical parameters in obtaining high-quality ECG signals. The electrode was shown to be biocompatible from the cytotoxicity test. A seven-day continuous wearability test showed that the quality of the ECG signal did not degrade over time, and skin reactions such as itching or erythema were not observed. This electrode could be used for the long-term measurement of other electrical biosignals for ubiquitous health monitoring including EMG, EEG, and ERG.

  13. Using mesoporous carbon electrodes for brackish water desalination.

    Science.gov (United States)

    Zou, Linda; Li, Lixia; Song, Huaihe; Morris, Gayle

    2008-04-01

    Electrosorptive deionisation is an alternative process to remove salt ions from the brackish water. The porous carbon materials are used as electrodes. When charged in low voltage electric fields, they possess a highly charged surface that induces adsorption of salt ions on the surface. This process is reversible, so the adsorbed salt ions can be desorbed and the electrode can be reused. In the study, an ordered mesoporous carbon (OMC) electrode was developed for electrosorptive desalination. The effects of pore arrangement pattern (ordered and random) and pore size distribution (mesopores and micropores) on the desalination performance was investigated by comparing OMC and activated carbon (AC). It were revealed from X-ray diffraction and N(2) sorption measurements that AC has both micropores and mesopores, whereas ordered mesopores are dominant in OMC. Their performance as potential electrodes to remove salt was evaluated by cyclic voltammetry (CV) and galvanostatic charge/discharge tests at a range of electrolyte concentrations and sweep rates. It is deduced that under the same electrochemical condition the specific capacitance values of OMC electrode (i.e. 133 F/g obtained from CV at a sweep rate of 1 mV/s in 0.1M NaCl solution) are larger than those of AC electrode (107 F/g), suggesting that the former has a higher desalting capacity than the latter. Furthermore, the OMC electrode shows a better rate capacity than the AC electrode. In addition, the desalination capacities were quantified by the batch-mode experiment at low voltage of 1.2V in 25 ppm NaCl solution (50 micros/cm conductivity). It was found that the adsorbed ion amounts of OMC and AC electrodes were 11.6 and 4.3 micromol/g, respectively. The excellent electrosorptive desalination performance of OMC electrode might be not only due to the suitable pore size (average of 3.3 nm) for the propagation of the salt ions, but also due to the ordered mesoporous structure that facilitates desorption of the

  14. Global ballast water management and the "same location" concept: a clear term or a clear issue?

    Science.gov (United States)

    David, Matej; Gollasch, Stephan; Pavliha, Marko

    2013-03-01

    The United Nations recognized the transfer of harmful organisms and pathogens across natural barriers as one of the four greatest pressures to the world's oceans and seas, causing global environmental changes, while also posing a threat to human health, property, and resources. Ballast water transferred by vessels was recognized as a prominent vector of such species and was regulated by the International Convention for the Control and Management of Ship's Ballast Water and Sediments (2004). Permanent exceptions from ballast water management requirements may apply when the uptake and discharge of ballast water occur at the "same location." However, the "same location" concept may be interpreted differently, e.g., a port basin, a port, an anchorage, or a larger area even with more ports inside. Considering that the Convention is nearing the beginning of enforcement, national authorities all around the world will soon be exposed to applications for exceptions. Here we consider possible effects of different interpretations of the "same location" concept. We have considered different possible extensions of the same location through environmental, shipping, and legal aspects. The extension of such areas, and the inclusion of more ports, may compromise the Convention's main purpose. We recommend that "same location" mean the smallest practicable unit, i.e., the same harbor, mooring, or anchorage. An entire smaller port, possibly also including the anchorage, could be considered as same location. For larger ports with a gradient of environmental conditions, "same location" should mean a terminal or a port basin. We further recommend that IMO consider the preparation of a guidance document to include concepts, criteria, and processes outlining how to identify "same location," which limits should be clearly identified.

  15. Optimisation of manufacturing parameters for a Ni-Ag fuel cell electrode

    Energy Technology Data Exchange (ETDEWEB)

    Pishbin, M.H. [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, Tehran (Iran); Mohammadi, A.R. [Department of Mechanical Engineering, University of British Columbia, Vancouver (Canada); Nasri, M. [Information Technology Company of Iran, Tehran (Iran)

    2007-08-15

    The aim of this research is to optimise manufacturing parameters for a fuel cell electrode. The combination of nickel oxide, silver oxide and ammonium bicarbonate powders is used to produce the electrode. The main role of silver element is to increase the activity in the electrode. Ni-Ag electrode can be used in fuel cells as positive and negative electrodes. All powders are mixed in the benzene solution by a magnetic mixer and then compressed to form green electrode. The range of pressure in this step is between 40 and 160 MPa. The green electrode is sintered in hydrogen atmosphere through a tube furnace and then cooled to 200 C under argon atmosphere. The range of sintering temperature and time is 500-800 C and 10-60 min, respectively. Also, silver oxide and ammonium bicarbonate percentages are varied from 20 to 65 and 15 to 35%, respectively. All parameters including composition, pressure, sintering temperature and time are changed during electrode fabrication to achieve optimised properties in the electrode. So, it is necessary to perform several tests measuring porosity, surface area, density, weight loss, mechanical strength, shrinkage, exchange current density and metallographic photos. The optimum conditions of the electrode production resulting from this investigation include compacting pressure 60 MPa, sintering temperature 560 C, sintering time 15 min, silver oxide percentage 50% and ammonium bicarbonate percentage 27%. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  16. Repeatability of phasic muscle activity: performance of surface and intramuscular wire electrodes in gait analysis.

    Science.gov (United States)

    Kadaba, M P; Wootten, M E; Gainey, J; Cochran, G V

    1985-01-01

    Repeatability is an important consideration for gait analysis data that are being used as an adjunct to clinical decision making. An index of repeatability may be based on a statistical criterion (variance ratio) that reflects similarity of wave forms over a number of identical cycles. The purpose of this study was to use the variance ratio to assess the repeatability of phasic muscle activity recorded with surface and bipolar intramuscular wire electrodes during gait on 10 normal subjects. Variance ratios were calculated using rectified and smoothed electromyographic data recorded simultaneously from the two types of electrodes. Three measures of repeatability (reproducibility, reliability, and constancy--defined as the cycle-to-cycle, run-to-run, and day-to-day repeatability of phasic muscle activity) were used to compare the performance of the two electrode techniques. Results show that the reproducibility and reliability were better for surface electrodes than for intramuscular wire electrodes, and constancy was good for surface electrodes and poor for intramuscular wire electrodes. Repeatability improved with increasing smoothing window lengths but was better for surface electrodes than wire electrodes, irrespective of the smoothing window. This study indicates that surface electrode data represent a more consistent measure of activity of superficial muscles, if comparisons are to be made between gait data from different test days.

  17. Efficacy of transgene expression in porcine skin as a function of electrode choice

    DEFF Research Database (Denmark)

    Gothelf, A; Mahmood, Faisal; Dagnaes-Hansen, Frederik;

    2011-01-01

    , have mainly been performed in rodents and the body of evidence on electrode choice and optimal pulsing conditions is limited. We therefore tested plate and needle electrodes in vivo in porcine skin, which resembles human skin in structure. The luciferase (pCMV-Luc) gene was injected intradermally...... and subsequently electroporated. Simultaneously, studies with gene electrotransfer to porcine skin using plasmids coding for green fluorescent protein (GFP) and betagalactosidase were performed. Interestingly, we found needle electrodes to be more efficient than plate electrodes (p...

  18. Preparation of polymer-modified electrodes: A literature and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Jayanta, P.S.; Ishida, Takanobu

    1991-05-01

    A literature review is presented on the field of polymer modified electrodes which can be electrochemically generated. It is suggested that a possible application of these polymer modified electrodes is as a regeneratable catalysis packing material for use in couter-current exchange columns. Secondly, there is a presentation of experimental results dealing with possible electrode modification using difluoro- and dimethyl- phenols and fluorinated derivatives of styrene, benzoquinone and hydroquinone. It appears that dimethylphenol shows the most potential of the monomers experimentally tested in providing a stable polymer modified electrode surface. 170 refs., 31 figs., 1 tab.

  19. Design, modelling and preliminary characterisation of microneedle-based electrodes for tissue electroporation in vivo

    Science.gov (United States)

    O'Mahony, Conor; Houlihan, Ruth; Grygoryev, Konstantin; Ning, Zhenfei; Williams, John; Moore, Tom

    2016-10-01

    We analysed the use of microneedle-based electrodes to enhance electroporation of mouse testis with DNA vectors for production of transgenic mice. Different microneedle formats were developed and tested, and we ultimately used electrodes based on arrays of 500 μm tall microneedles. In a series of experiments involving injection of a DNA vector expressing Green Fluorescent Protein (GFP) and electroporation using microneedle electrodes and a commercially available voltage supply, we compared the performance of flat and microneedle electrodes by measuring GFP expression at various timepoints after electroporation. Our main finding, supported by both experimental and simulated data, is that needles significantly enhanced electroporation of testis.

  20. Damped button electrode for B-Factory BPM system

    Energy Technology Data Exchange (ETDEWEB)

    Shintake, T.; Akasaka, N.; Obina, T.; Chin, Y.H. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

    1996-08-01

    A new concept of damping of resonances in a button electrode has been proposed and tested in the BPM system for the B-Factory project at KEK (KEKB). Since a very high current beam has to be stored in the machine, even a small resonance in the ring will result in losing a beam due to multi-bunch instabilities. In a conventional button electrode used in BPMs, a TE110 mode resonance can be trapped in the gap between the electrode and the vacuum chamber. In order to damp this mode, the diameter of the electrode has been chosen to be small to increase the resonance frequency and to radiate the power into the beam pipe. In addition, an asymmetric structure is applied to extract the EM energy of the TE110 mode into the coaxial cable as the propagating TEM mode which has no cut-off frequency. Results of the computer simulations and tests with cold models are reported. The quality factor of the TE110 mode was small enough due to the radiation into the beam pipe even in the conventional electrode and the mode coupling effect due to the asymmetric shape was significant on a cavity-like TE111 mode. (author)

  1. Optimized optical clearing method for imaging central nervous system

    Science.gov (United States)

    Yu, Tingting; Qi, Yisong; Gong, Hui; Luo, Qingming; Zhu, Dan

    2015-03-01

    The development of various optical clearing methods provides a great potential for imaging entire central nervous system by combining with multiple-labelling and microscopic imaging techniques. These methods had made certain clearing contributions with respective weaknesses, including tissue deformation, fluorescence quenching, execution complexity and antibody penetration limitation that makes immunostaining of tissue blocks difficult. The passive clarity technique (PACT) bypasses those problems and clears the samples with simple implementation, excellent transparency with fine fluorescence retention, but the passive tissue clearing method needs too long time. In this study, we not only accelerate the clearing speed of brain blocks but also preserve GFP fluorescence well by screening an optimal clearing temperature. The selection of proper temperature will make PACT more applicable, which evidently broaden the application range of this method.

  2. Numerical simulation of deep cryogenic treatment electrode tip temperature for spot welding aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Wu Zhisheng; Hu Minying; Liu Cuirong

    2006-01-01

    Deep cryogenic treatment technology of electrodes is put forward to improve electrode life of resistance spot welding of aluminum alloy LF2. Deep cryogenic treatment makes electrode life for spot welding aluminum alloy improve. The specific resistivity of the deep cryogenic treatment electrodes is tested and experimental results show that specific resistivity is decreased sharply. The temperature field and the influence of deep cryogenic treatment on the electrode tip temperature during spot welding aluminium alloy is studied by numerical simulation method with the software ANSYS. The axisymmetric finite element model of mechanical, thermal and electrical coupled analysis of spot welding process is developed. The numerical simulation results show that the influence of deep cryogenic treatment on electrode tip temperature is very large.

  3. Preparation and properties of low-cost graphene counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Wu, Qishuang; Shen, Yue; Wang, Qiandi; Gu, Feng; Cao, Meng; Wang, Linjun

    2013-12-01

    With the advantages of excellent electrical properties, high catalytic activity and low-cost preparation, Graphene is one of the most expected carbon materials to replace the expensive Pt as counter electrodes for dye-sensitized solar cells (DSSCs). In this paper, graphene counter electrodes were obtained by simple doctor-blade coating method on fluorine tin oxides (FTOs). The samples were investigated by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope (SEM). Then the low-cost graphene electrodes were applied in typical sandwich-type DSSCs with TiO2 or ZnO as photoanodes, and their photoelectric conversion efficiency (η) were about 4.34% and 2.28%, respectively, which were a little lower than those of Pt electrodes but much higher than those of graphite electrodes. This law was consistent with the test results of electrochemical impedance spectroscopy (EIS). Low-cost graphene electrodes can be applied in DSSCs by process optimization.

  4. The Impact of Enzyme Orientation and Electrode Topology on the Catalytic Activity of Adsorbed Redox Enzymes

    Science.gov (United States)

    McMillan, Duncan G. G.; Marritt, Sophie J.; Kemp, Gemma L.; Gordon-Brown, Piers; Butt, Julea N.; Jeuken, Lars J. C.

    2014-01-01

    It is well established that the structural details of electrodes and their interaction with adsorbed enzyme influences the interfacial electron transfer rate. However, for nanostructured electrodes, it is likely that the structure also impacts on substrate flux near the adsorbed enzymes and thus catalytic activity. Furthermore, for enzymes converting macro-molecular substrates it is possible that the enzyme orientation determines the nature of interactions between the adsorbed enzyme and substrate and therefore catalytic rates. In essence the electrode may impede substrate access to the active site of the enzyme. We have tested these possibilities through studies of the catalytic performance of two enzymes adsorbed on topologically distinct electrode materials. Escherichia coli NrfA, a nitrite reductase, was adsorbed on mesoporous, nanocrystalline SnO2 electrodes. CymA from Shewanella oneidensis MR-1 reduces menaquinone-7 within 200 nm sized liposomes and this reaction was studied with the enzyme adsorbed on SAM modified ultra-flat gold electrodes. PMID:24634538

  5. The Impact of Enzyme Orientation and Electrode Topology on the Catalytic Activity of Adsorbed Redox Enzymes.

    Science.gov (United States)

    McMillan, Duncan G G; Marritt, Sophie J; Kemp, Gemma L; Gordon-Brown, Piers; Butt, Julea N; Jeuken, Lars J C

    2013-11-01

    It is well established that the structural details of electrodes and their interaction with adsorbed enzyme influences the interfacial electron transfer rate. However, for nanostructured electrodes, it is likely that the structure also impacts on substrate flux near the adsorbed enzymes and thus catalytic activity. Furthermore, for enzymes converting macro-molecular substrates it is possible that the enzyme orientation determines the nature of interactions between the adsorbed enzyme and substrate and therefore catalytic rates. In essence the electrode may impede substrate access to the active site of the enzyme. We have tested these possibilities through studies of the catalytic performance of two enzymes adsorbed on topologically distinct electrode materials. Escherichia coli NrfA, a nitrite reductase, was adsorbed on mesoporous, nanocrystalline SnO2 electrodes. CymA from Shewanella oneidensis MR-1 reduces menaquinone-7 within 200 nm sized liposomes and this reaction was studied with the enzyme adsorbed on SAM modified ultra-flat gold electrodes.

  6. Bipolarly stacked electrolyser for energy and space efficient fabrication of supercapacitor electrodes

    Science.gov (United States)

    Liu, Xiaojuan; Wu, Tao; Dai, Zengxin; Tao, Keran; Shi, Yong; Peng, Chuang; Zhou, Xiaohang; Chen, George Z.

    2016-03-01

    Stacked electrolysers with titanium bipolar plates are constructed for electrodeposition of polypyrrole electrodes for supercapacitors. The cathode side of the bipolar Ti plates are pre-coated with activated carbon. In this new design, half electrolysis occurs which significantly lowers the deposition voltage. The deposited electrodes are tested in a symmetrical unit cell supercapacitor and an asymmetrical supercapacitor stack. Both devices show excellent energy storage performances and the capacitance values are very close to the design value, suggesting a very high current efficiency during the electrodeposition. The electrolyser stack offers multi-fold benefits for preparation of conducting polymer electrodes, i.e. low energy consumption, facile control of the electrode capacitance and simultaneous preparation of a number of identical electrodes. Therefore, the stacked bipolar electrolyser is a technology advance that offers an engineering solution for mass production of electrodeposited conducting polymer electrodes for supercapacitors.

  7. Development of new metal matrix composite electrodes for electrical discharge machining through powder metallurgy process

    Directory of Open Access Journals (Sweden)

    C. Mathalai Sundaram

    2014-12-01

    Full Text Available Electrical discharge machining (EDM is one of the widely used nontraditional machining methods to produce die cavities by the erosive effect of electrical discharges. This method is popular due to the fact that a relatively soft electrically conductive tool electrode can machine hard work piece. Copper electrode is normally used for machining process. Electrode wear rate is the major drawback for EDM researchers. This research focus on fabrication of metal matrix composite (MMC electrode by mixing copper powder with titanium carbide (TiC and Tungsten carbide (WC powder through powder metallurgy process, Copper powder is the major amount of mixing proportion with TiC and WC. However, this paper focus on the early stage of the project where powder metallurgy route was used to determine suitable mixing time, compaction pressure and sintering and compacting process in producing EDM electrode. The newly prepared composite electrodes in different composition are tested in EDM for OHNS steel.

  8. RETGEM with polyvinylchloride (PVC) electrodes

    CERN Document Server

    Razin, V I; Reshetin, A I; Filippov, S N

    2009-01-01

    This paper presents a new design of the RETGEM (Resistive Electrode Thick GEM) based on electrodes made of a polyvinylchloride material (PVC). Our device can operate with gains of 10E5 as a conventional TGEM at low counting rates and as RPC in the case of high counting rates without of the transit to the violent sparks. The distinct feature of present RETGEM is the absent of the metal coating and lithographic technology for manufacturing of the protective dielectric rms. The electrodes from PVC permit to do the holes by a simple drilling machine. Detectors on a RETGEM basis could be useful in many fields of an application requiring a more cheap manufacturing and safe operation, for example, in a large neutrino experiments, in TPC, RICH systems.

  9. Neural stimulation and recording electrodes.

    Science.gov (United States)

    Cogan, Stuart F

    2008-01-01

    Electrical stimulation of nerve tissue and recording of neural electrical activity are the basis of emerging prostheses and treatments for spinal cord injury, stroke, sensory deficits, and neurological disorders. An understanding of the electrochemical mechanisms underlying the behavior of neural stimulation and recording electrodes is important for the development of chronically implanted devices, particularly those employing large numbers of microelectrodes. For stimulation, materials that support charge injection by capacitive and faradaic mechanisms are available. These include titanium nitride, platinum, and iridium oxide, each with certain advantages and limitations. The use of charge-balanced waveforms and maximum electrochemical potential excursions as criteria for reversible charge injection with these electrode materials are described and critiqued. Techniques for characterizing electrochemical properties relevant to stimulation and recording are described with examples of differences in the in vitro and in vivo response of electrodes.

  10. Nonequilibrium Thermodynamics of Porous Electrodes

    CERN Document Server

    Ferguson, Todd R

    2012-01-01

    We review classical porous electrode theory and extend it to non-ideal active materials, including those capable of phase transformations. Using principles of non-equilibrium thermodynamics, we relate the cell voltage, ionic fluxes, and Faradaic charge-transfer kinetics to the variational electrochemical potentials of ions and electrons. The Butler-Volmer exchange current is consistently expressed in terms of the activities of the reduced, oxidized and transition states, and the activation overpotential is defined relative to the local Nernst potential. We also apply mathematical bounds on effective diffusivity to estimate porosity and tortuosity corrections. The theory is illustrated for a Li-ion battery with active solid particles described by a Cahn-Hilliard phase-field model. Depending on the applied current and porous electrode properties, the dynamics can be limited by electrolyte transport, solid diffusion and phase separation, or intercalation kinetics. In phase-separating porous electrodes, the model...

  11. Composite Electrodes for Electrochemical Supercapacitors

    Directory of Open Access Journals (Sweden)

    Yang QuanMin

    2010-01-01

    Full Text Available Abstract 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.

  12. Photonic Flash Sintering of Ink-Jet-Printed Back Electrodes for Organic Photovoltaic Applications

    NARCIS (Netherlands)

    Polino, G.; Shanmugam, S.; Bex, G.J.P.; Abbel, R.J.; Brunetti, F.; Di Carlo, A.; Andriessen, H.A.J.M.; Galagan, Y.O.

    2016-01-01

    A study of the photonic flash sintering of a silver nanoparticle ink printed as the back electrode for organic solar cells is presented. A number of sintering settings with different intensities and pulse durations have been tested on both full-area and grid-based silver electrodes, using the comple

  13. Battery electrodes: Properties and performance. (Latest citations from the EI Compendex*plus database). Published Search

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The bibliography contains citations concerning battery electrodes relative to research and development. Topics discuss electrode technology, chemical solutions, materials improvement, reactions, and rechargeability and reliability. Electrochemical and thermodynamic characteristics, materials testing and evaluation, and corrosion protection are also included. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  14. Nanoengineered membrane electrode assembly interface

    Science.gov (United States)

    Song, Yujiang; Shelnutt, John A

    2013-08-06

    A membrane electrode structure suitable for use in a membrane electrode assembly (MEA) that comprises membrane-affixed metal nanoparticles whose formation is controlled by a photochemical process that controls deposition of the metal nanoparticles using a photocatalyst integrated with a polymer electrolyte membrane, such as an ionomer membrane. Impregnation of the polymer membrane with the photocatalyst prior to metal deposition greatly reduces the required amount of metal precursor in the deposition reaction solution by restricting metal reduction substantially to the formation of metal nanoparticles affixed on or near the surface of the polymer membrane with minimal formation of metallic particles not directly associated with the membrane.

  15. Robust high temperature oxygen sensor electrodes

    DEFF Research Database (Denmark)

    Lund, Anders

    Platinum is the most widely used material in high temperature oxygen sensor electrodes. However, platinum is expensive and the platinum electrode may, under certain conditions, suffer from poisoning, which is detrimental for an oxygen sensor. The objective of this thesis is to evaluate electrode ......-based electrodes and one porous electrode based on the perovskite-structured strontium and vanadiumdoped lanthanum chromium oxide (LSCV) were investigated. The porous electrodes were applied on yttrium-stabilised zirconium oxide (YSZ) substrates in a collaboration with the company PBI...

  16. Ultrasound guided electrochemotherapy for the treatment of a clear cell thymoma in a cat

    Science.gov (United States)

    Spugnini, Enrico Pierluigi; Menicagli, Francesco; Pettorali, Michela; Baldi, Alfonso

    2017-01-01

    A twelve-year-old male castrated domestic shorthair cat was presented for rapidly progressing respiratory distress. The cat was depressed, tachypneic and moderately responsive. Ultrasonography showed a mediastinal mass associated with a significant pleural effusion that needed tapping every five to seven days. Ultrasound guided biopsy yielded a diagnosis of clear cell thymoma upon histopathology. After complete staging procedures, the owner elected to treat the cat with electrochemotherapy (ECT) using systemic bleomycin. Two sessions of ultrasound guided ECT were performed at two week intervals with trains of biphasic electric pulses applied using needle electrodes until complete coverage of the area was achieved. The treatment was well tolerated and resulted in partial remission (PR). Additional sessions were performed on a monthly basis. The cat is still in PR after fourteen months. ECT resulted in improved local control and should be considered among the available adjuvant treatments in pets carrying visceral tumors. PMID:28331834

  17. The Clearing : Heidegger’s Lichtung and the big scrub

    Directory of Open Access Journals (Sweden)

    Garbutt, Rob

    2010-01-01

    Full Text Available Clearings make settlement possible. Whether on a small scale using an axe and other hand implements to make way for a dwelling and a garden, or on a large scale with a chain strung between two D9 bulldozers in preparation for a major agribusiness development, the process of clearing creates spaces for installing something new. This paper uses the idea of (the clearing, as practice, process, outcome and metaphor, to examine the installation of the locals in a settler society. Using Lismore on the far-north coast of New South Wales, Australia, as a case example, the particular work of clearing that is discussed here is a practice that enables a form of colonisation and settlement that distances itself from its history of migration. This is a history of settler locals who were 'always here', and a colonial form of clearing clears the land and the mind of troubling pasts and of troubling presences. For the locals within a place, then, clearing manages and simplifies a complex set of social and material relations, histories and identities.Using Anthony Appiah's concept the 'space clearing gesture', the paper concludes with a reflection on the space in which the idea of "the clearing" and this paper appears. Do places, in this instance rural places, provide a type of clearing in which certain ideas might appear that may not appear elsewhere? If situatedness matters then the diversity of places where thinking is done is important for our ecology of thought, and in connection with this, perhaps what 'rural cultural studies' does is clear a particular type of space for thinking.

  18. The Clearing: Heidegger’s Lichtung and The Big Scrub

    Directory of Open Access Journals (Sweden)

    Rob Garbutt

    2010-02-01

    Full Text Available Clearings make settlement possible. Whether on a small scale using an axe and other hand implements to make way for a dwelling and a garden, or on a large scale with a chain strung between two D9 bulldozers in preparation for a major agribusiness development, the process of clearing creates spaces for installing something new. This paper uses the idea of (the clearing, as practice, process, outcome and metaphor, to examine the installation of the locals in a settler society. Using Lismore on the far-north coast of New South Wales, Australia, as a case example, the particular work of clearing that is discussed here is a practice that enables a form of colonisation and settlement that distances itself from its history of migration. This is a history of settler locals who were 'always here', and a colonial form of clearing clears the land and the mind of troubling pasts and of troubling presences. For the locals within a place, then, clearing manages and simplifies a complex set of social and material relations, histories and identities. Using Anthony Appiah's concept the 'space clearing gesture', the paper concludes with a reflection on the space in which the idea of "the clearing" and this paper appears. Do places, in this instance rural places, provide a type of clearing in which certain ideas might appear that may not appear elsewhere? If situatedness matters then the diversity of places where thinking is done is important for our ecology of thought, and in connection with this, perhaps what 'rural cultural studies' does is clear a particular type of space for thinking.

  19. Effect of mechanical optical clearing on near-infrared spectroscopy.

    Science.gov (United States)

    Idelson, Christopher R; Vogt, William C; King-Casas, Brooks; LaConte, Stephen M; Rylander, Christopher G

    2015-08-01

    Near-infrared Spectroscopy (NIRS) is a broadly utilized technology with many emerging applications including clinical diagnostics, sports medicine, and functional neuroimaging, to name a few. For functional brain imaging NIR light is delivered at multiple wavelengths through the scalp and skull to the brain to enable spatial oximetry measurements. Dynamic changes in brain oxygenation are highly correlated with neural stimulation, activation, and function. Unfortunately, NIRS is currently limited by its low spatial resolution, shallow penetration depth, and, perhaps most importantly, signal corruption due to light interactions with superficial non-target tissues such as scalp and skull. In response to these issues, we have combined the non-invasive and rapidly reversible method of mechanical tissue optical clearing (MOC) with a commercially available NIRS system. MOC utilizes a compressive loading force on tissue, causing the lateral displacement of blood and water, while simultaneously thinning the tissue. A MOC-NIRS Breath Hold Test displayed a ∼3.5-fold decrease in the time-averaged standard deviation between channels, consequentially promoting greater channel agreement. A Skin Pinch Test was implemented to negate brain and muscle activity from affecting the recorded signal. These results displayed a 2.5-3.0 fold increase in raw signal amplitude. Existing NIRS instrumentation has been further integrated within a custom helmet device to provide a uniform force distribution across the NIRS sensor array. These results showed a gradual decrease in time-averaged standard deviation among channels with an increase in applied pressure. Through these experiments, and the development of the MOC-NIRS helmet device, MOC appears to provide enhancement of NIRS technology beyond its current limitations.

  20. Analysis of SOFCs Using Reference Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Finklea, H.; Chen, X.; Gerdes, K.; Pakalapati, S.; Celik, I.

    2013-01-01

    Reference electrodes are frequently applied to isolate the performance of one electrode in a solid oxide fuel cell. However, reference electrode simulations raise doubt to veracity of data collected using reference electrodes. The simulations predict that the reported performance for the one electrode will frequently contain performance of both electrodes. Nonetheless, recent reports persistently treat data so collected as ideally isolated. This work confirms the predictions of the reference electrode simulations on two SOFC designs, and to provides a method of validating the data measured in the 3-electrode configuration. Validation is based on the assumption that a change in gas composition to one electrode does not affect the impedance of the other electrode at open circuit voltage. This assumption is supported by a full physics simulation of the SOFC. Three configurations of reference electrode and cell design are experimentally examined using various gas flows and two temperatures. Impedance data are subjected to deconvolution analysis and equivalent circuit fitting and approximate polarization resistances of the cathode and anode are determined. The results demonstrate that the utility of reference electrodes is limited and often wholly inappropriate. Reported impedances and single electrode polarization values must be scrutinized on this basis.

  1. Behind the money market: clearing and settling money market instruments

    OpenAIRE

    David L. Mengle

    1992-01-01

    When a money market instrument is traded, the clearing and settlement process establishes the change in ownership. Because the process involves both costs and risks, money market participants have developed means of making clearing and settlement more efficient and less risky.

  2. Glycogen-rich clear cell carcinoma of the breast

    DEFF Research Database (Denmark)

    Sørensen, Flemming Brandt; Paulsen, S M

    1987-01-01

    The light microscopic, immunohistochemical and ultrastructural features of a clear cell carcinoma of the breast have been studied. Both intraductal and invasive components were found. Histochemistry showed large amounts of intracytoplasmic glycogen and sparse neutral mucin in the tumour. The tumour...... was classified as a mucin-containing variant of glycogen-rich, clear cell carcinoma of the breast....

  3. 75 FR 63113 - Financial Resources Requirements for Derivatives Clearing Organizations

    Science.gov (United States)

    2010-10-14

    ... customers or themselves, and non-FCMs that clear solely on behalf of themselves. See also the definition of... member may have a specific incentive to pay an assessment depending on the size and profitability of its... purposes of this calculation, if a clearing member had pays in both its house and customer accounts,...

  4. The Effectiveness of Clear Speech as a Masker

    Science.gov (United States)

    Calandruccio, Lauren; Van Engen, Kristin; Dhar, Sumitrajit; Bradlow, Ann R.

    2010-01-01

    Purpose: It is established that speaking clearly is an effective means of enhancing intelligibility. Because any signal-processing scheme modeled after known acoustic-phonetic features of clear speech will likely affect both target and competing speech, it is important to understand how speech recognition is affected when a competing speech signal…

  5. 76 FR 14471 - Clearing Agency Standards for Operation and Governance

    Science.gov (United States)

    2011-03-16

    ... Operation and Governance; Proposed Rule #0;#0;Federal Register / Vol. 76, No. 51 / Wednesday, March 16, 2011... Standards for Operation and Governance AGENCY: Securities and Exchange Commission. ACTION: Proposed rule... clearing agencies and standards for the operation and governance of clearing agencies. The proposed...

  6. ClearPEM: prototype PET device dedicated to breast imaging

    CERN Multimedia

    Joao Varela

    2009-01-01

    Clinical trials have begun in Portugal on a new breast imaging system (ClearPEM) using positron emission tomography (PET). The system, developed by a Portuguese consortium in collaboration with CERN and laboratories participating in the Crystal Clear collaboration, will detect even the smallest tumours and thus help avoid unnecessary biopsies.

  7. 18 CFR 367.1840 - Account 184, Clearing accounts.

    Science.gov (United States)

    2010-04-01

    ... ACT Balance Sheet Chart of Accounts Deferred Debits § 367.1840 Account 184, Clearing accounts. This account must include undistributed balances in clearing accounts at the date of the balance sheet... accounts. 367.1840 Section 367.1840 Conservation of Power and Water Resources FEDERAL ENERGY...

  8. A simple formula for determining globally clear skies

    Energy Technology Data Exchange (ETDEWEB)

    Long, C.N.; George, A.T.; Mace, G.G. [Penn State Univ., University Park, PA (United States)] [and others

    1996-04-01

    Surface measurements to serve as {open_quotes}ground truth{close_quotes} are of primary importance in the development of retrieval algorithms using satellite measurements to predict surface irradiance. The most basic algorithms of this type deal with clear sky (i.e., cloudless) top-to-surface shortwave (SW) transfer, serving as a necessary prerequisite towards treating both clear and cloudy conditions. Recently, atmosphere SW cloud forcing to infer the possibility of excess atmospheric absorption (compared with model results) in cloudy atmospheres. The surface component of this ratio relies on inferring the expected clear sky SW irradiance to determine the effects of clouds on the SW energy budget. Solar renewable energy applications make use of clear and cloud fraction climatologies to assess solar radiation resources. All of the above depend to some extent on the identification of globally clear sky conditions and the attendant measurements of downwelling SW irradiance.

  9. Performance Measurement of AMTEC Electrode

    Institute of Scientific and Technical Information of China (English)

    MA; Jun-ping; HE; Hu; LI; Si-jie; TANG; Xian; LUO; Zhi-fu

    2015-01-01

    Alkali metal thermal to electric converter(AMTEC)is a direct energy conversion device capable of near-Carnot efficiencies,and has demonstrated the performance of high power density,high current low voltage.Electrode is a key component of achieving high efficiency in an AMTEC device.A RhW alloy target was used for deposition

  10. Desalination with carbon aerogel electrodes. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Richardson, J.H.; Fix, D.V. [Lawrence Livermore National Lab., CA (United States); Thomson, S.L.; May, S.C. [Bechtel National, Inc., San Francisco, CA (United States)

    1996-12-04

    Electrically regenerated electrosorption process (carbon aerogel CDI) was developed by LLNL for continuously removing ionic impurities from aqueous streams. A salt solution flows in a channel formed by numerous pairs of parallel carbon aerogel electrodes. Each electrode has a very high BET surface area (2-5.4x10{sup 6}ft{sup 2}lb{sup -1} or 400-1100 m{sup 2}g{sup -1}) and very low electrical resistivity ({le}40 m{Omega}). Ions are removed from the electrolyte by the electric field and electrosorbed onto the carbon aerogel. It is concluded that carbon aerogel CDI may be an energy-efficient alternative to electrodialysis and reverse osmosis for desalination of brackish water ({le}5000 ppM). The intrinsic energy required by this process is about QV/2, where Q is the stored electrical charge and V is the voltage between the electrodes, plus losses. Estimated requirement for desalination of a 2000 ppM feed is -0.53-2.5 Wh/gal{sup -1} (0.5-2.4 kJ L{sup -1}), depending on voltage, flow rate, cell dimensions, aerogel density, recovery ratio, etc. This assumes that 50-70% of the stored electrical energy is reclaimed during regeneration (electrical discharge). Though the energy requirement for desalination of sea water is also low, this application will be much more difficult. Additional work will be required for desalination of streams that contain more than 5000 ppM total dissolved solids (2000 ppM will require electrochemical cells with extremely tight, demanding tolerances). At this present time, the process is best suited for streams with dilute impurities, as recently demonstrated during a field test at LLNL Treatment Facility C.

  11. A LabVIEW based experiment system for the efficient collection and analysis of cyclic voltametry and electrode charge capacity measurements.

    Science.gov (United States)

    Detlefsen, D; Hu, Z; Troyk, P R

    2006-01-01

    Cyclic voltametry and recording of stimulation electrode voltage excursions are two critical methods of measurement for understanding the performance of implantable electrodes. Because implanted electrodes cannot easily be replaced, it is necessary to have an a-priori understanding of an electrode's implanted performance and capabilities. In-vitro exhaustive tests are often needed to quantify an electrodes performance. Using commonly available equipment, the human labor cost to conduct this work is immense. Presented is an automated experiment system that is highly configurable that can efficiently conduct a battery of repeatable CV and stimulation recording measurements. Results of preparing 96 electrodes prior to an animal implantation are also discussed.

  12. 21 CFR 870.2360 - Electrocardiograph electrode.

    Science.gov (United States)

    2010-04-01

    ... electrode. (a) Identification. An electrocardiograph electrode is the electrical conductor which is applied to the surface of the body to transmit the electrical signal at the body surface to a processor...

  13. A method for making a hydrogen electrode

    Energy Technology Data Exchange (ETDEWEB)

    Ikeyama, M.; Ivaki, T.; Yanagikhara, N.

    1983-09-08

    A metallic grid is pressed to the surface of a foam metallic plate which contains powders of a compound which adsorb H2. The electrode is processed at the powder caking temperature. The electrode has a long service life.

  14. Solid Oxide Electrolysis Cells: Microstructure and Degradation of the Ni/Yttria-Stabilized Zirconia Electrode

    DEFF Research Database (Denmark)

    Hauch, Anne; Ebbesen, Sune; Jensen, Søren Højgaard;

    2008-01-01

    Solid oxide fuel cells produced at Risø DTU have been tested as solid oxide electrolysis cells for steam electrolysis by applying an external voltage. Varying the sealing on the hydrogen electrode side of the setup verifies that the previously reported passivation over the first few hundred hours...... of electrolysis testing was an effect of the applied glass sealing. Degradation of the cells during long-term galvanostatic electrolysis testing [850°C, −1/2 A/cm2, p(H2O)/p(H2)=0.5/0.5] was analyzed by impedance spectroscopy and the degradation was found mainly to be caused by increasing polarization resistance...... associated with the hydrogen electrode. A cell voltage degradation of 2%/1000 h was obtained. Postmortem analysis of cells tested at these conditions showed that the electrode microstructure could withstand at least 1300 h of electrolysis testing, however, impurities were found in the hydrogen electrode...

  15. DEFORMATION INFLUENCE ON A LIFETIME OF WELDING ELECTRODE TIPS

    Directory of Open Access Journals (Sweden)

    Ján Viňáš

    2009-02-01

    Full Text Available The contribution deals with the influence of welding electrode tips deformation on their lifetime. The influence of material properties, production technology and the intensity of welding electrodes load on their lifetime are presented. The electrode tips of the most used type of CuCr1Zr alloy of three basic standard shapes before and after the process of welding are evaluated. The process of welding is realized with low, middle and maximum welding parameters on programmable pneumatic spot welding machine VTS BPK 20. The influence of welding parameters on chosen material characteristics of welding tips is observed. Through the use of upsetting test, dependency of forming strength and deformation of material on used technology of welding tip production is observed.

  16. High-performance battery electrodes via magnetic templating

    Science.gov (United States)

    Sander, J. S.; Erb, R. M.; Li, L.; Gurijala, A.; Chiang, Y.-M.

    2016-08-01

    In lithium-ion batteries, the critical need for high-energy-density, low-cost storage for applications ranging from wearable computing to megawatt-scale stationary storage has created an unmet need for facile methods to produce high-density, low-tortuosity, kinetically accessible storage electrodes. Here we show that magnetic control of sacrificial features enables the creation of directional pore arrays in lithium-ion electrodes. The directional pores result in faster charge transport kinetics and enable electrodes with more than threefold higher area capacity (for example, >12 mAh cm-2 versus charge-discharge rates. We demonstrate these capabilities in laboratory cells under various test conditions, including an electric vehicle model drive cycle.

  17. Active C4 Electrodes for Local Field Potential Recording Applications

    Directory of Open Access Journals (Sweden)

    Lu Wang

    2016-02-01

    Full Text Available Extracellular neural recording, with multi-electrode arrays (MEAs, is a powerful method used to study neural function at the network level. However, in a high density array, it can be costly and time consuming to integrate the active circuit with the expensive electrodes. In this paper, we present a 4 mm × 4 mm neural recording integrated circuit (IC chip, utilizing IBM C4 bumps as recording electrodes, which enable a seamless active chip and electrode integration. The IC chip was designed and fabricated in a 0.13 μm BiCMOS process for both in vitro and in vivo applications. It has an input-referred noise of 4.6 μV rms for the bandwidth of 10 Hz to 10 kHz and a power dissipation of 11.25 mW at 2.5 V, or 43.9 μW per input channel. This prototype is scalable for implementing larger number and higher density electrode arrays. To validate the functionality of the chip, electrical testing results and acute in vivo recordings from a rat barrel cortex are presented.

  18. Active C4 Electrodes for Local Field Potential Recording Applications

    Science.gov (United States)

    Wang, Lu; Freedman, David; Sahin, Mesut; Ünlü, M. Selim; Knepper, Ronald

    2016-01-01

    Extracellular neural recording, with multi-electrode arrays (MEAs), is a powerful method used to study neural function at the network level. However, in a high density array, it can be costly and time consuming to integrate the active circuit with the expensive electrodes. In this paper, we present a 4 mm × 4 mm neural recording integrated circuit (IC) chip, utilizing IBM C4 bumps as recording electrodes, which enable a seamless active chip and electrode integration. The IC chip was designed and fabricated in a 0.13 μm BiCMOS process for both in vitro and in vivo applications. It has an input-referred noise of 4.6 μVrms for the bandwidth of 10 Hz to 10 kHz and a power dissipation of 11.25 mW at 2.5 V, or 43.9 μW per input channel. This prototype is scalable for implementing larger number and higher density electrode arrays. To validate the functionality of the chip, electrical testing results and acute in vivo recordings from a rat barrel cortex are presented. PMID:26861324

  19. Systematic experimental study of pure shear type dielectric elastomer membranes with different electrode and film thicknesses

    Science.gov (United States)

    Hodgins, M.; Seelecke, S.

    2016-09-01

    An approach to reduce the voltage required for dielectric elastomer actuators is to reduce film thickness. However, if the electrode thickness is not similarly reduced, the electrode’s mechanical behavior can increasingly and negatively impact the overall actuator behavior. This effect is yet to be studied and quantified for pure shear type specimens; a type recommended in a recent DE standardization journal publication. Therefore, in this work, using pure shear specimens, a comparative study of membrane actuators of different film thickness (20, 50 and 100 μm) is performed. Electrodes of different thicknesses are screen printed and tested in a uniaxial test device. The stiffening effect due to the solid-state electrodes is demonstrated by performing force-elongation tests for specimens with and without electrodes. Additionally the importance of thin electrodes (relative to film thickness) was demonstrated through a number of electromechanical tests. Isotonic tests revealed a lower electro-mechanical sensitivity for the 20 μm film when compared with the 50 and 100 μm films. This was attributed to the relatively thick electrodes. Best actuation results were achieved when the total electrode thickness was at least 15x thinner than the dielectric membrane thickness.

  20. Molecular basis for optical clearing of collagenous tissues

    Science.gov (United States)

    Hirshburg, Jason M.; Ravikumar, Krishnakumar M.; Hwang, Wonmuk; Yeh, Alvin T.

    2010-09-01

    Molecular interactions of optical clearing agents were investigated using a combination of molecular dynamics (MD) simulations and optical spectroscopy. For a series of sugar alcohols with low to high optical clearing potential, Raman spectroscopy and integrating sphere measurements were used to quantitatively characterize tissue water loss and reduction in light scattering following agent exposures. The rate of tissue water loss was found to correlate with agent optical clearing potential, but equivalent tissue optical clearing was measured in native and fixed tissue in vitro, given long-enough exposure times to the polyol series. MD simulations showed that the rate of tissue optical clearing correlated with the preferential formation of hydrogen bond bridges between agent and collagen. Hydrogen bond bridge formation disrupts the collagen hydration layer and facilitates replacement by a chemical agent to homogenize tissue refractive index. However, the reduction in tissue light scattering did not correlate with the agent index of refraction. Our results suggest that a necessary property of optical clearing agents is hyperosmolarity to tissue, but that the most effective agents with the highest rates of optical clearing are a subset with the highest collagen solubilities.

  1. Memory operations in Au nanoparticle single-electron transistors with floating gate electrodes

    Science.gov (United States)

    Azuma, Yasuo; Sakamoto, Masanori; Teranishi, Toshiharu; Majima, Yutaka

    2016-11-01

    Floating gate memory operations are demonstrated in a single-electron transistor (SET) fabricated by a chemical assembly using the Au nanogap electrodes and the chemisorbed Au nanoparticles. By applying pulse voltages to the control gate, phase shifts were clearly and stably observed both in the Coulomb oscillations and in the Coulomb diamonds. Writing and erasing operations on the floating gate memory were reproducibly observed, and the charges on the floating gate electrodes were maintained for at least 12 h. By considering the capacitance of the floating gate electrode, the number of electrons in the floating gate electrode was estimated as 260. Owing to the stability of the fabricated SET, these writing and erasing operations on the floating gate memory can be applied to reconfigurable SET circuits fabricated by a chemically assembled technique.

  2. 21 CFR 890.1175 - Electrode cable.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrode cable. 890.1175 Section 890.1175 Food... DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1175 Electrode cable. (a) Identification. An electrode cable is a device composed of strands of insulated electrical conductors...

  3. An ionization chamber with magnetic levitated electrodes

    CERN Document Server

    Kawaguchi, T

    1999-01-01

    A new type of ionization chamber which has magnetically levitated electrodes has been developed. The electrodes are supplied voltages for the repelling of ions by a battery which is also levitated with the electrodes. The characteristics of this ionization chamber are investigated in this paper.

  4. Voltammetry at porous electrodes: A theoretical study

    CERN Document Server

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

    2014-01-01

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

  5. Membrane electrode assembly for a fuel cell

    Science.gov (United States)

    Prakash, Surya (Inventor); Narayanan, Sekharipuram R. (Inventor); Atti, Anthony (Inventor); Olah, George (Inventor); Smart, Marshall C. (Inventor)

    2006-01-01

    A catalyst ink for a fuel cell including a catalytic material and poly(vinylidene fluoride). The ink may be applied to a substrate to form an electrode, or bonded with other electrode layers to form a membrane electrode assembly (MEA).

  6. Reducing Insertion Sites of Penetrating Multipolar Shaft Electrodes by Double Side Electrode Arrangement

    Science.gov (United States)

    2007-11-02

    Abstract-Micromachined devices with substrate-integrated elec- trodes are the key component in implantable microdevices for recording neuronal ...INSERTION SITES OF PENETRATING MULTIPOLAR SHAFT ELECTRODES BY DOUBLE SIDE ELECTRODE ARRANGEMENT T.Stieglitz1, P. Heiduschka2, M. Schuettler1, M. Gross1...and Subtitle Reducing Insertion Sites of Penetrating Multipolar Shaft Electrodes by Double Side Electrode Arrangement Contract Number Grant Number

  7. Measurement of noise and impedance of dry and wet textile electrodes, and textile electrodes with hydrogel.

    Science.gov (United States)

    Puurtinen, Merja M; Komulainen, Satu M; Kauppinen, Pasi K; Malmivuo, Jaakko A V; Hyttinen, Jari A K

    2006-01-01

    Textile sensors, when embedded into clothing, can provide new ways of monitoring physiological signals, and improve the usability and comfort of such monitoring systems in the areas of medical, occupational health and sports. However, good electrical and mechanical contact between the electrode and the skin is very important, as it often determines the quality of the signal. This paper introduces a study where the properties of dry textile electrodes, textile electrodes moistened with water, and textile electrodes covered with hydrogel were studied with five different electrode sizes. The aim was to study how the electrode size and preparation of the electrode (dry electrode/wet electrode/electrode covered with hydrogel membrane) affect the measurement noise, and the skin-electrode impedance. The measurement noise and skin-electrode impedance were determined from surface biopotential measurements. These preliminary results indicate that noise level increases as the electrode size decreases. The noise level is high in dry textile electrodes, as expected. Yet, the noise level of wet textile electrodes is quite low and similar to that of textile electrodes covered with hydrogel. Hydrogel does not seem to improve noise properties, however it may have effects on movement artifacts. Thus, it is feasible to use textile embedded sensors in physiological monitoring applications when moistening or hydrogel is applied.

  8. A Handy EEG Electrode Set for patients suffering from altered mental state.

    Science.gov (United States)

    Lepola, Pasi; Myllymaa, Sami; Töyräs, Juha; Hukkanen, Taina; Mervaala, Esa; Määttä, Sara; Lappalainen, Reijo; Myllymaa, Katja

    2015-12-01

    Although electroencephalography (EEG) is an important diagnostic tool for investigating patients with unexplained altered mental state (AMS), recording of emergency EEG is not a clinical routine. This is mainly due to the cumbersome electrode solutions. A Handy EEG Electrode Set consists of ten EEG, two EOG, two ground and two commutative reference hydrogel-coated silver wire electrodes attached to a thin polyester carrier film. The clinical usefulness of the Handy EEG Electrode Set was tested in 13 patients (five females, eight males) with AMS. EEG recordings were conducted at the same time with a standard 10-20 electrode set. The registration in the first patient case without the behind-ear electrodes (T9 and T10), indicated that these electrodes are very crucial to provide clinically relevant information from posterior regions of brain. In following 12 cases, the sensitivity and specificity for detecting EEG abnormality based on the Handy EEG Electrode Set recordings were 83 and 100 %, respectively. The Handy EEG Electrode Set proved to be easy to use and to provide valuable information for the neurophysiological evaluation of a patient suffering from AMS. However, further studies with larger number of patients are warranted to clarify the true diagnostic accuracy and applicability of this approach.

  9. Invisible Base Electrode Coordinates Approximation for Simultaneous SPECT and EEG Data Visualization

    Directory of Open Access Journals (Sweden)

    Kowalczyk L.

    2014-04-01

    Full Text Available This work was performed as part of a larger research concerning the feasibility of improving the localization of epileptic foci, as compared to the standard SPECT examination, by applying the technique of EEG mapping. The presented study extends our previous work on the development of a method for superposition of SPECT images and EEG 3D maps when these two examinations are performed simultaneously. Due to the lack of anatomical data in SPECT images it is a much more difficult task than in the case of MRI/EEG study where electrodes are visible in morphological images. Using the appropriate dose of radioisotope we mark five base electrodes to make them visible in the SPECT image and then approximate the coordinates of the remaining electrodes using properties of the 10-20 electrode placement system and the proposed nine-ellipses model. This allows computing a sequence of 3D EEG maps spanning on all electrodes. It happens, however, that not all five base electrodes can be reliably identified in SPECT data. The aim of the current study was to develop a method for determining the coordinates of base electrode(s missing in the SPECT image. The algorithm for coordinates approximation has been developed and was tested on data collected for three subjects with all visible electrodes. To increase the accuracy of the approximation we used head surface models. Freely available model from Oostenveld research based on data from SPM package and our own model based on data from our EEG/SPECT studies were used. For data collected in four cases with one electrode not visible we compared the invisible base electrode coordinates approximation for Oostenveld and our models. The results vary depending on the missing electrode placement, but application of the realistic head model significantly increases the accuracy of the approximation.

  10. Clear cell sarcoma: A case mimicking primary cutaneous malignant melanoma

    Directory of Open Access Journals (Sweden)

    Rodriguez-Martin M

    2009-01-01

    Full Text Available Clear cell sarcoma (CCS is a recently described variant of sarcoma characterized by prominent clear cells showing features similar to clear cell melanoma. This neoplasm was first described by Dr. Franz M. Erzinger. Primary CCS usually arises in deeper soft tissues, in association with fascia, tendons, or aponeuroses. Characteristic translocation t(12;22 (q13;q12 has been considered pathognomonic for CCS. Prognosis is related to tumor size. An early recognition and initial radical surgery is the key to a favourable outcome. We present a patient with an unusual neoplasm that resembled malignant melanoma.

  11. Clear-PEM, a dedicated PET camera for mammography

    CERN Document Server

    Lecoq, P

    2002-01-01

    Preliminary results suggest that Positron Emission Mammography (PEM) can offer a noninvasive method for the diagnosis of breast cancer. Metabolic images from PEM contain unique information not available from conventional morphologic imaging techniques and aid in expeditiously establishing the diagnosis of cancer. A dedicated machine seems to offer better perspectives in terms of position resolution and sensitivity. This paper describes the concept of Clear-PEM, the system presently developed by the Crystal Clear Collaboration at CERN for an evaluation of this approach. This device is based on new crystals introduced by the Crystal Clear as well as on modern data acquisition techniques developed for the large experiments in high energy physics experiments.

  12. Ultrathin metallic interlayers in vacuum deposited MoOx/metal/MoOx electrodes for organic solar cells

    Science.gov (United States)

    Travkin, V. V.; Luk'yanov, A. Yu.; Drozdov, M. N.; Vopilkin, E. A.; Yunin, P. A.; Pakhomov, G. L.

    2016-12-01

    Eight types of practically important metals were tested as interlayers in MoOx/Metal/MoOx composite electrodes. Ultrathin semitransparent electrodes with a fixed thickness were deposited on glass, using thermal vacuum evaporation, and characterized by various microscopic and X-ray techniques and by mass spectrometry profiling. The optical transmission and sheet resistance of the electrodes were compared as key parameters for photovoltaic applications. We attempted to find correlations between the chemical properties of embedded metals and the structural/conducting properties of composite electrodes. In general, the electrodes with noble metal interlayers feature a better conductivity, whereas their average transparency in the visible and near infrared range is similar to that of electrodes with reactive metals. Diffusion and oxidation processes in composite electrodes were examined by the SIMS depth profiling technique.

  13. Mechanism of Silicon Electrode Aging upon Cycling in Full Lithium-Ion Batteries.

    Science.gov (United States)

    Delpuech, Nathalie; Dupre, Nicolas; Moreau, Philippe; Bridel, Jean-Sebastian; Gaubicher, Joel; Lestriez, Bernard; Guyomard, Dominique

    2016-04-21

    Understanding the aging mechanism of silicon-based negative electrodes for lithium-ion batteries upon cycling is essential to solve the problem of low coulombic efficiency and capacity fading and further to implement this new high-capacity material in commercial cells. Nevertheless, such studies have so far focused on half cells in which silicon is cycled versus an infinite reservoir of lithium. In the present work, the aging mechanism of silicon-based electrodes is studied upon cycling in a full Li-ion cell configuration with LiCoO2 as the positive electrode. Postmortem analyses of both electrodes clearly indicate that neither one of them contains lithium and that no discernible degradation results from the cycling. The aging mechanism can be explained by the reduction of solvent molecules. Electrons extracted from the positive electrode are responsible for an internal imbalance in the cell, which results in progressive slippage of the electrodes and reduces the compositional range of cyclable lithium ions for both electrodes.

  14. ENOBIO dry electrophysiology electrode; first human trial plus wireless electrode system.

    Science.gov (United States)

    Ruffini, Giulio; Dunne, Stephen; Farres, Esteve; Cester, Ivan; Watts, Paul C P; Silva, S P; Grau, Carles; Fuentemilla, Lluis; Marco-Pallares, Josep; Vandecasteele, Bjorn

    2007-01-01

    This paper presents the results of the first human trials with the ENOBIO electrophysiology electrode prototype plus the initial results of a new wireless prototype with flexible electrodes based on the same platform. The results indicate that a dry active electrode that employs a CNT array as the electrode interface can perform on a par with traditional "wet" electrodes for the recording of EEG, ECG, EOG and EMG. We also demonstrate a new platform combining wireless technology plus flexible electrodes for improved comfort for applications that take advantage of the dry electrode concept.

  15. Clear cell myoepithelial carcinoma of salivary glands showing EWSR1 rearrangement: molecular analysis of 94 salivary gland carcinomas with prominent clear cell component.

    Science.gov (United States)

    Skálová, Alena; Weinreb, Ilan; Hyrcza, Martin; Simpson, Roderick H W; Laco, Jan; Agaimy, Abbas; Vazmitel, Marina; Majewska, Hanna; Vanecek, Tomas; Talarčik, Peter; Manajlovic, Spomenka; Losito, Simona N; Šteiner, Petr; Klimkova, Adela; Michal, Michal

    2015-03-01

    This study examines the presence of the EWSR1 rearrangement in a variety of clear cell salivary gland carcinomas with myoepithelial differentiation. A total of 94 salivary gland carcinomas with a prominent clear cell component included 51 cases of clear cell myoepithelial carcinomas de novo (CCMC), 21 cases of CCMCs ex pleomorphic adenoma (CCMCexPA), 11 cases of epithelial-myoepithelial carcinoma (EMC), 6 cases of EMC with solid clear cell overgrowth, and 5 cases of hyalinizing clear cell carcinoma of minor salivary glands. In addition, 10 cases of myoepithelial carcinomas devoid of clear cell change and 12 cases of benign myoepithelioma were included as well. All the tumors in this spectrum were reviewed, reclassified, and tested by fluorescence in situ hybridization (FISH) for the EWSR1 rearrangement using the Probe Vysis EWSR1 Break Apart FISH Probe Kit. The EWSR1 rearrangement was detected in 20 of 51 (39%) cases of CCMC, in 5 of 21 (24%) cases of CCMCexPA, in 1 of 11 (9%) cases of EMC, and in 4 of 5 (80%) cases of hyalinizing clear cell carcinoma. The 25 EWSR1-rearranged CCMCs and CCMCexPAs shared similar histomorphology. They were arranged in nodules composed of compact nests of large polyhedral cells with abundant clear cytoplasm. Necrosis, areas of squamous metaplasia, and hyalinization were frequent features. Immunohistochemically, the tumors expressed p63 (96%), cytokeratin CK14 (96%), and S100 protein (88%). MIB1 index varied from 10% to 100%, with most cases in the 20% to 40% range. Clinical follow-up information was available in 21 cases (84%) and ranged from 3 months to 15 years (mean 5.2 y); 4 patients were lost to follow-up. Ten patients are alive with no evidence of recurrent or metastatic disease in the follow-up period from 3 months to 15 years (mean 5 y), 3 patients are alive with recurrent and metastatic disease, and 8 died of disseminated cancer 9 months to 16 years after diagnosis (mean 6 y). Lymph node metastasis appeared in 5 patients

  16. Towards the clinical use of concentric electrodes in ECG recordings: influence of ring dimensions and electrode position

    Science.gov (United States)

    Prats-Boluda, G.; Ye-Lin, Y.; Bueno-Barrachina, JM; Rodriguez de Sanabria, R.; Garcia-Casado, J.

    2016-02-01

    To overcome the limited spatial resolution of standard 12-lead ECG recordings, concentric ring electrodes (CRE) have been proposed to provide valuable data for the diagnosis of a wide range of cardiac abnormalities, including infarction and arrhythmia. Although theoretical studies indicate that the dimensions of the CRE regulate the depth of the electric dipoles sensed by these electrodes, this has not been experimentally confirmed. The aim of this work was to analyze the influence of CRE dimensions and position of a wireless multi-CRE sensor node on the cardiac signal recorded. For this, four wireless multichannel ECG recording nodes based on flexible multi-ring electrodes were placed at positions CMV1 (position comparable to V1), CMV2, CMV4R and CMV5; each node providing three bipolar concentric ECG signals (BC-ECG). Standard 12-lead ECG and 12 BC-ECG signals were recorded in 29 volunteers. The results revealed that a ring with an outer diameter of 33.5 mm achieves a balance between the ease-of-use and spatial resolution of smaller electrodes and improved detectability and higher amplitudes of signals from larger ring electrodes. Although a standard 12-lead ECG outperforms BC-ECC recordings in detectability of cardiac waves, if the relative amplitude of the wave is also considered, BC-ECG at CMV1 proved superior at picking up atrial activity. In fact, in most of the BC-ECG signals picked up at CMV1, P1 and P2 atrial activity waves were more clearly identified than in simultaneous 12-Lead ECG signals. Likewise, BC-ECG signals revealed higher spatial resolution in detecting anomalous electrical activity in local regions, such as impaired intraventricular driving, or atrioventricular blocks. Finally, the wireless multi-CRE sensor node provides enhanced comfort and handling to both patient and clinician over wired systems.

  17. Reconstruction of Clear-PEM data with STIR

    CERN Document Server

    Martins, M V; Rodrigues, P; Trindade, A; Oliveira, N; Correia, M; Cordeiro, H; Ferreira, N C; Varela, J; Almeida, P

    2006-01-01

    The Clear-PEM scanner is a device based on planar detectors that is currently under development within the Crystal Clear Collaboration, at CERN. The basis for 3D image reconstruction in Clear-PEM is the software for tomographic image reconstruction (STIR). STIR is an open source object-oriented library that efficiently deals with the 3D positron emission tomography data sets. This library was originally designed for the traditional cylindrical scanners. In order to make its use compatible with planar scanner data, new functionalities were introduced into the library's framework. In this work, Monte Carlo simulations of the Clear-PEM scanner acquisitions were used as input for image reconstruction with the 3D OSEM algorithm available in STIR. The results presented indicate that dual plate PEM data can be accurately reconstructed using the enhanced STIR framework.

  18. Molecular Air Data Clear Air Turbulence Sensor: MADCAT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear air turbulence (CAT), often referred to as "air pockets," is attributed to Kelvin-Helmholtz instabilities at altitudes generally above 18,000ft, often in the...

  19. Molecular Air Data Clear Air Turbulence Sensor: MADCAT Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear air turbulence (CAT), often referred to as "air pockets," is attributed to Kelvin-Helmholtz instabilities at altitudes usually above 18,000ft, often without...

  20. Functional imaging in bulk tissue specimens using optical emission tomography: fluorescence preservation during optical clearing

    Science.gov (United States)

    Sakhalkar, H. S.; Dewhirst, M.; Oliver, T.; Cao, Y.; Oldham, M.

    2007-04-01

    Optical emission computed tomography (optical-ECT) is a technique for imaging the three-dimensional (3D) distribution of fluorescent probes in biological tissue specimens with high contrast and spatial resolution. In optical-ECT, functional information can be imaged by (i) systemic application of functional labels (e.g. fluorophore labelled proteins) and/or (ii) endogenous expression of fluorescent reporter proteins (e.g. red fluorescent protein (RFP), green fluorescent protein (GFP)) in vivo. An essential prerequisite for optical-ECT is optical clearing, a procedure where tissue specimens are made transparent to light by sequential perfusion with fixing, dehydrating and clearing agents. In this study, we investigate clearing protocols involving a selection of common fixing (4% buffered paraformaldehyde (PFA), methanol and ethanol), dehydrating (methanol and ethanol) and clearing agents (methyl salicylate and benzyl-alcohol-benzyl-benzoate (BABB)) in order to determine a 'fluorescence friendly' clearing procedure. Cell culture experiments were employed to optimize the sequence of chemical treatments that best preserve fluorescence. Texas red (TxRed), fluorescein isothiocyanate (FITC), RFP and GFP were tested as fluorophores and fluorescent reporter proteins of interest. Fluorescent and control cells were imaged on a microscope using a DSred2 and FITC filter set. The most promising clearing protocols of cell culture experiments were applied to whole xenograft tumour specimens, to test their effectiveness in large unsectioned samples. Fluorescence of TxRed/FITC fluorophores was not found to be significantly affected by any of the test clearing protocols. RFP and GFP fluorescence, however, was found to be significantly greater when cell fixation was in ethanol. Fixation in either PFA or methanol resulted in diminished fluorescence. After ethanol fixation, the RFP and GFP fluorescence proved remarkably robust to subsequent exposure to either methyl salicylate or BABB

  1. All-solid-state potassium-selective electrode using graphene as the solid contact

    DEFF Research Database (Denmark)

    Li, Fenghua; Ye, Junjin; Zhou, Min;

    2012-01-01

    microscopy, scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The performance of the new K+−selective electrodes was examined by a potentiometric water layer test, potentiometric measurements, and current reversal chronopotentiometry. The obtained potentiometric...

  2. Global horizontal irradiance clear sky models : implementation and analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Hansen, Clifford W.; Reno, Matthew J.

    2012-03-01

    Clear sky models estimate the terrestrial solar radiation under a cloudless sky as a function of the solar elevation angle, site altitude, aerosol concentration, water vapor, and various atmospheric conditions. This report provides an overview of a number of global horizontal irradiance (GHI) clear sky models from very simple to complex. Validation of clear-sky models requires comparison of model results to measured irradiance during clear-sky periods. To facilitate validation, we present a new algorithm for automatically identifying clear-sky periods in a time series of GHI measurements. We evaluate the performance of selected clear-sky models using measured data from 30 different sites, totaling about 300 site-years of data. We analyze the variation of these errors across time and location. In terms of error averaged over all locations and times, we found that complex models that correctly account for all the atmospheric parameters are slightly more accurate than other models, but, primarily at low elevations, comparable accuracy can be obtained from some simpler models. However, simpler models often exhibit errors that vary with time of day and season, whereas the errors for complex models vary less over time.

  3. Coastal sediment elevation change following anthropogenic mangrove clearing

    Science.gov (United States)

    Hayden, Heather L.; Granek, Elise F.

    2015-11-01

    Coastal mangrove forests along tropical shorelines serve as an important interface between land and sea. They provide a physical buffer protecting the coastline from erosion and act as sediment "traps" catching terrestrial sediment, thus preventing smothering of subtidal coral reefs. Coastal development that removes mangrove habitat may impact adjacent nearshore coral reefs through sedimentation and nutrient loading. We examined differences in sediment elevation change between patches of open-coast intact and anthropogenically cleared red mangroves (Rhizophora mangle) on the east side of Turneffe Atoll, Belize, to quantify changes following mangrove clearing. Samples were collected over a 24 month period at five study sites, each containing paired intact (+mangrove) and cleared (-mangrove) plots. Five sediment elevation pins were deployed in each plot: behind areas cleared of mangroves (-mangrove) and behind adjacent intact mangroves (+mangrove). Sediment elevation increased at intact mangrove sites (M = +3.83 mm, SE = 0.95) whereas cleared mangrove areas suffered elevation loss (M = -7.30 mm, SE = 3.38). Mangroves inshore of partial or continuous gaps in the adjacent fringing reefs had higher rates of elevation loss (M = -15.05 mm) than mangroves inshore of continuous fringing reefs (M = -1.90 mm). Our findings provide information on potential effects of mangrove clearing and the role of offshore habitat characteristics on coastal sediment trapping and maintenance of sediment elevation by mangroves. With implications for coastline capacity to adjust to sea level rise, these findings are relevant to management of coastal fringing mangrove forests across the Caribbean.

  4. Long life lithium batteries with stabilized electrodes

    Science.gov (United States)

    Amine, Khalil; Liu, Jun; Vissers, Donald R.; Lu, Wenquan

    2009-03-24

    The present invention relates to non-aqueous electrolytes having electrode stabilizing additives, stabilized electrodes, and electrochemical devices containing the same. Thus the present invention provides electrolytes containing an alkali metal salt, a polar aprotic solvent, and an electrode stabilizing additive. In some embodiments the additives include a substituted or unsubstituted cyclic or spirocyclic hydrocarbon containing at least one oxygen atom and at least one alkenyl or alkynyl group. When used in electrochemical devices with, e.g., lithium manganese oxide spinel electrodes or olivine or carbon-coated olivine electrodes, the new electrolytes provide batteries with improved calendar and cycle life.

  5. Method for manufacturing magnetohydrodynamic electrodes

    Science.gov (United States)

    Killpatrick, Don H.; Thresh, Henry R.

    1982-01-01

    A method of manufacturing electrodes for use in a magnetohydrodynamic (MHD) generator comprising the steps of preparing a billet having a core 10 of a first metal, a tubular sleeve 12 of a second metal, and an outer sheath 14, 16, 18 of an extrusile metal; evacuating the space between the parts of the assembled billet; extruding the billet; and removing the outer jacket 14. The extruded bar may be made into electrodes by cutting and bending to the shape required for an MDH channel frame. The method forms a bond between the first metal of the core 10 and the second metal of the sleeve 12 strong enough to withstand a hot and corrosive environment.

  6. Surface modification of recording electrodes

    OpenAIRE

    Iaci Miranda Pereira; Sandhra Maria de Carvalho; Rodrigo Lambert Oréfice; Marcelo Bariatto Andrade Fontes; Lilian Anee Muniz Arantes; Núbia Figueiró; Maria de Fátima Leite; Hercules Pereira Neves

    2013-01-01

    Waterborne Polyurethanes (PUs) are a family of polymers that contains urethane linkages synthesized in an aqueous environment and are thus free of organic solvents. Recently, waterborne PUs have been extensively studied for biomedical applications because of their biocompatibility. The present work investigates the following: (1) the impact on electrical performance of electrode materials (platinum and silicon) modified chemically by a layer of waterborne PU, and (2) the behavior of rat cardi...

  7. Mortality in patients with chronic and cleared hepatitis C viral infection: a nationwide cohort study

    DEFF Research Database (Denmark)

    Omland, Lars Haukali; Krarup, Henrik; Jepsen, Peter;

    2010-01-01

    It is unknown whether mortality differs between patients with chronic hepatitis C virus (HCV) replication and those who cleared the virus after infection. We examined the impact of chronic HCV replication on mortality among Danish patients testing positive for HCV antibodies....

  8. 78 FR 42809 - Self-Regulatory Organizations; Fixed Income Clearing Corporation; Order Approving Proposed Rule...

    Science.gov (United States)

    2013-07-17

    ... Futures Trading Commission.\\8\\ The swap transactions executed by trueEX are cleared by a clearinghouse..., notes, bonds, Treasury inflation-protected securities (TIPS) and separate trading of registered interest..., including testing trueEX's trade input and receipt of output capabilities prior to the go-live date....

  9. LiNi0.8Co0.2O2-based high-power lithium-ion battery positive electrodes analyzed by X-ray photoelectron spectroscopy: 4. Following calendar-life test for 8 weeks at 50 °C, 60% state-of-charge (3.747 V)

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, Daniel A; Haasch, Richard T.

    2017-01-01

    High-power lithium-ion batteries are rapidly replacing the nickel metal hydride batteries currently used for energy storage in hybrid electric vehicles. Widespread commercialization of these batteries for vehicular applications is, however, limited by calendar-life performance, thermal abuse characteristics, and cost. The Advanced Technology Development Program was established by the U.S. Department of Energy to address these limitations. An important objective of this program was the development and application of diagnostic tools that provide unique ways to investigate the phenomena that limit lithium-ion cell life, performance, and safety characteristics. This report introduces a set of six Surface Science Spectra xray photoelectron spectroscopy (XPS) comparison records of data collected from positive electrodes (cathode) harvested from cylindrically wound, 18650-type, 1 A h capacity cells. The cathodes included in this study are (1) fresh, (2) following three formation cycles, (3) following calendar-life test for 12 weeks at 40 C, 60% state-of-charge (SOC), (4) following calendar-life test for 8 weeks at 50 C, 60% SOC, (5) following calendar-life test for 8 weeks at 60 C, 60% SOC, and (6) following calendar-life test for 2 weeks at 70 C, 60% SOC.

  10. LiNi 0.8 Co 0.2 O 2 -based high power lithium-ion battery positive electrodes analyzed by x-ray photoelectron spectroscopy: 3. Following calendar-life test for 12 weeks at 40 °C, 60% state-of-charge (3.747 V)

    Energy Technology Data Exchange (ETDEWEB)

    Haasch, Richard T.; Abraham, Daniel A.

    2016-12-01

    High-power lithium-ion batteries are rapidly replacing the nickel metal hydride batteries currently used for energy storage in hybrid electric vehicles. Widespread commercialization of these batteries for vehicular applications is, however, limited by calendar-life performance, thermal abuse characteristics, and cost. The Advanced Technology Development Program was established by the U.S. Department of Energy to address these limitations. An important objective of this program was the development and application of diagnostic tools that provide unique ways to investigate the phenomena that limit lithium-ion cell life, performance, and safety characteristics. This report introduces a set of six Surface Science Spectra xray photoelectron spectroscopy (XPS) comparison records of data collected from positive electrodes (cathode) harvested from cylindrically wound, 18650-type, 1 A h capacity cells. The cathodes included in this study are (1) fresh, (2) following three formation cycles, (3) following calendar-life test for 12 weeks at 40 C, 60% state-of-charge (SOC), (4) following calendar-life test for 8 weeks at 50 C, 60% SOC, (5) following calendar-life test for 8 weeks at 60 C, 60% SOC, and (6) following calendar-life test for 2 weeks at 70 C, 60% SOC.

  11. Electrode materials for rechargeable battery

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Christopher; Kang, Sun-Ho

    2015-09-08

    A positive electrode is disclosed for a non-aqueous electrolyte lithium rechargeable cell or battery. The electrode comprises a lithium containing material of the formula Na.sub.yLi.sub.xNi.sub.zMn.sub.1-z-z'M.sub.z'O.sub.d, wherein M is a metal cation, x+y>1, 0electrode material can be synthesized using an ion-exchange reaction with a lithium salt in an organic-based solvent to partially replace sodium ions of a precursor material with lithium ions.

  12. Peltier effects in electrode carbon

    Science.gov (United States)

    Hansen, Ellen Marie; Egner, Espen; Kjelstrup, Signe

    1998-02-01

    The thermoelectric power of a cell with platinum electrodes and a carbon conductor was determined. The electromotive force (emf) was measured as a function of the temperature difference between the electrodes at temperatures varying from 310 °C to 970 °C. From these measurements, the transported entropy of electric charge in carbon was found to vary from -1.7 to -1.9 J/(K mole) at temperatures around 300 °C, from -2.0 to -2.3 J/(K mole) at temperatures around 550 °C, and from -3.4 to -3.7 J/(K mole) at temperatures around 950 °C. This transported entropy had not before been determined for temperatures above 550 °C. Also, it is shown how the previously neglected surface properties can be taken into account to interpret the measurements. In the Hall-Héroult cell, the anode is made of a similar kind of carbon. Hence, the transported entropy found above can be used to describe the often neglected coupling between transport of heat and electric charge in this electrode. It is shown that the calculated electric potential profile through a coal sample will change significantly if the coupling is neglected, but the calculated temperature profile is independent of whether the coupling is neglected. New equations are also developed that can be used to evaluate the importance of the coupling in other systems.

  13. Redox electrode materials for supercapatteries

    Science.gov (United States)

    Yu, Linpo; Chen, George Z.

    2016-09-01

    Redox electrode materials, including transition metal oxides and electronically conducting polymers, are capable of faradaic charge transfer reactions, and play important roles in most electrochemical energy storage devices, such as supercapacitor, battery and supercapattery. Batteries are often based on redox materials with low power capability and safety concerns in some cases. Supercapacitors, particularly those based on redox inactive materials, e.g. activated carbon, can offer high power output, but have relatively low energy capacity. Combining the merits of supercapacitor and battery into a hybrid, the supercapattery can possess energy as much as the battery and output a power almost as high as the supercapacitor. Redox electrode materials are essential in the supercapattery design. However, it is hard to utilise these materials easily because of their intrinsic characteristics, such as the low conductivity of metal oxides and the poor mechanical strength of conducting polymers. This article offers a brief introduction of redox electrode materials, the basics of supercapattery and its relationship with pseudocapacitors, and reviews selectively some recent progresses in the relevant research and development.

  14. A Active Micromachined Scalp Electrode Array for Eeg Signal Recording.

    Science.gov (United States)

    Alizadeh-Taheri, Babak

    This thesis describes the design, microfabrication, and testing of an active scalp EEG (electroencephalograph) electrode that has several distinct advantages over existing technologies. These advantages are: (1) no electrolyte used, (2) no skin preparation, (3) significantly reduced sensor size, and (4) compatibility with EEG monitoring systems. The active electrode array is an integrated system made of an array of capacitive sensors with local integrated circuitry housed in a package with batteries to power the circuitry. This level of integration was required to achieve the functional performance obtained by the electrode. The electrode consists of a silicon sensor substrate fabricated at UCD and a custom circuit substrate fabricated at Orbit Semiconductors, using a 2 μm analog CMOS technology. The circuitry was designed for low 1/f noise. One side of the sensor substrate holds four capacitive sensors with rm Si_3N _4 as the dielectric material. The opposite side holds aluminum pads for bonding to the circuit substrate. A via hole technology was developed to make electrical contact to both sides of the sensor substrate. The via holes are 200 μm square openings etched through the silicon by a reactive ion etching (RIE) process using an rm SF_6/O_2 gas mixture, oxidized, and then filled with sputtered aluminum for contacts through the substrate. The via holes have an aspect ratio of 2:1 (length of opening to depth of hole). Silicon RIE etch rates of up to 18 mu/hr were obtained under optimum conditions, using a 0.8 μm aluminum mask. The circuit and sensor substrates were bonded with silver adhesive, and wire bonding was used to make electrical contacts between the substrates. The two substrates were then integrated in a custom package for testing. The electrode was tested on an electrical test bench and on human subjects in four modalities of EEG activity, namely: (1) spontaneous EEG, (2) sensory event-related potentials, (3) brain stem potentials, and (4

  15. Use of short-term (5-Minute) and long-term (18-Hour) leaching tests to characterize, fingerprint, and rank mine-waste material from historical mines in the Deer Creek, Snake River, and Clear Creek Watersheds in and around the Montezuma Mining District, Colorado

    Science.gov (United States)

    Hageman, Philip L.

    2004-01-01

    Precipitation-induced runoff from historical mine-waste located adjacent to the headwaters of the Snake River, Deer Creek, Saints John Creek, Grizzly Gulch, Stevens Gulch, and Leavenworth Creek contributes to the degradation of water quality in these streams. Because historical mine-waste piles have had long-term exposure to the atmosphere, it is surmised that runoff from these piles, induced by meteorological events such as cloudbursts and snowmelt, may cause mobility of acid and metals into a watershed due to dissolution of soluble minerals. For this study, 13 mine-waste composite samples from various mine-wastes in these drainage basins were leached using both a short-term and a long-term leach test. Analytical results from this combination of leach tests are tools that allow the investigator to quantify (fingerprint) which geochemical components could be expected in runoff from these piles if they were leached by a cloudburst (5-minute leach test), as well as what the ?worst-case? geochemical profile would look like if the material were subject to extended leaching and breakdown of the mine-waste material (18-hour leach test). Also, this combination of leach tests allows the geoscientist the ability to see geochemical changes in the mine-waste leachate over time. That is, does the leachate become more or less acidic over time; does the specific conductance increase or decrease; and are there changes in the concentrations of major or trace elements? Further, use of a ranking scheme described herein will aid in prediction of which historical mine-waste piles have the greatest potential for impact on a watershed should runoff occur. Because of long-term weathering of these historical mine-waste piles, geochemical profiles, leachate time-trends, and relative ranking of the mine-wastes produced from analysis of the leachates are Hageman_SIR_2508.doc 1 7/21/2004 2:50 PM indicative of how the mine-waste piles can be expected to act in the environment and may help to

  16. Electrochemical reduction of NO on La2-xSrxNiO4 based electrodes

    DEFF Research Database (Denmark)

    Simonsen, Vibe Louise Ernlund; Nørskov, Linda; Hagen, Anke;

    2009-01-01

    The series La2 − x Sr x NiO4 (x = 0.0, 0.05, 0.15, 0.25, 0.35, and 1.0) was tested for functionality as electrode materials for direct electrochemical reduction of NO. The materials were tested using cyclic voltammetry in 1% NO and 10% O2 in Ar on a cone-shaped electrode. The best materials...

  17. Effect of precordial electrocardiographic electrode placement on ST-segment measurement during exercise.

    Science.gov (United States)

    Bertolet, B D; Boyette, A F; Mardis, M; Hill, J A

    1995-04-01

    Research protocols often utilize serial exercise testing to examine the efficacy of anti-ischemic therapies. These tests, however, are prone to multiple sources of bias. This investigation sought to determine the influence of varying precordial electrocardiographic (ECG) electrode placement on the detection of exercise-induced ST-segment shifts. Fifteen coronary artery disease patients with abnormal exercise tests were studied. Based on the previous exercise test, the precordial electrode position exhibiting the greatest ST-segment shift was selected as the reference electrode. Four additional electrodes were placed around this reference electrode and exercise testing was performed. ECG strips were recorded every minute. The time-to-onset and -offset of ischemic-type ST-segment depression was recorded. ST-segment depression was recorded during exercise from the reference electrode in 12 of 15 patients. Ischemic-type ST-depression was also recorded in each of these 12 patients with the surrounding electrodes; however, the time-to-onset detected by all four surrounding electrodes concurred in only 5 of 12 (42%) patients. The time-to-offset of the ST-segment depression concurred in 9 of 12 (75%) patients. Serial ECGs recorded from similar but not exactly the same precordial ECG electrode position should yield similar results for the detection of ischemia, but time-to-onset or -offset of ischemia may differ by 60 s or more. Small changes in the time-to-onset and -offset of ischemia should not be considered reliable indicators of anti-ischemia efficacy.

  18. MASS TRANSFER LIMITATION IN DIFFERENT ANODE ELECTRODE SURFACE AREAS ON THE PERFORMANCE OF DUAL CHAMBER MICROBIAL FUEL CELL

    Directory of Open Access Journals (Sweden)

    Majid Sadeqzadeh

    2012-01-01

    Full Text Available In this study, the effect of different electrode surface areas on the performance of dual chamber Microbial Fuel Cells (MFC was investigated. Four different electrodes with 12, 16, 20 and 24 cm2 surface areas were tested in an MFC system. The 20 cm2 electrode generated an output power of 76.5 mW/m2 was found to be the highest among all the electrodes tested. This might be due to better interactions with microorganism and less mass transfer limitation. In addition, this indicates that the chances for attachment of bacteria and generation of electricity in larger electrode surface areas might be limited by mass transport and by higher surface area. The output power generation was then followed by the 16, 12 and 24 cm2 electrodes which generated 69.6, 64.7 and 61.25 mW/m2 electricity, respectively.

  19. Anterior Crossbite and Crowding Correction with a Series of Clear Aligners Involving Lower Incisor Extraction: "The Clear Way" Case Report.

    Science.gov (United States)

    Bawaskar, Naval Suresh

    2015-01-01

    The Clear Aligner can be used to correct tooth movement without involving extraction, surgery, and other adjunct orthopaedic appliances. Some forms ofattachments are required with clear aligners to achieve all major types of orthodontic tooth movements. The Clear Aligner is a procedure that can be performed by a clinician with computer simulation/calculation. Since the Clear Aligner can be fabricated in steps, it is readily available to change the treatment sequence throughout the course of the treatment in cases of complex malocclusions. The patient can receive any necessary dental procedures with ease during the course of the treatment. The treatment can also be easily resumed even if the patient has not worn the aligners for a period of time. The purpose of this article is to report dental anterior crossbite correction with a series of Clear Aligners without the use of any forms of attachments. The Clear Aligner could be used as an alternative in appropriate cases for those who are reluctant with conventional appliances.

  20. Electrochemiluminescence at Bare and DNA-Coated Graphite Electrodes in 3D-Printed Fluidic Devices.

    Science.gov (United States)

    Bishop, Gregory W; Satterwhite-Warden, Jennifer E; Bist, Itti; Chen, Eric; Rusling, James F

    Clear plastic fluidic devices with ports for incorporating electrodes to enable electrochemiluminescence (ECL) measurements were prepared using a low-cost, desktop three-dimensional (3D) printer based on stereolithography. Electrodes consisted of 0.5 mm pencil graphite rods and 0.5 mm silver wires inserted into commercially available 1/4 in.-28 threaded fittings. A bioimaging system equipped with a CCD camera was used to measure ECL generated at electrodes and small arrays using 0.2 M phosphate buffer solutions containing tris(2,2'-bipyridyl)dichlororuthenium(II) hexahydrate ([Ru(bpy)3](2+)) with 100 mM tri-n-propylamine (TPA) as the coreactant. ECL signals produced at pencil graphite working electrodes were linear with respect to [Ru(bpy)3](2+) concentration for 9-900 μM [Ru(bpy)3](2+). The detection limit was found to be 7 μM using the CCD camera with exposure time set at 10 s. Electrode-to-electrode ECL signals varied by ±7.5%. Device performance was further evaluated using pencil graphite electrodes coated with multilayer poly(diallyldimethylammonium chloride) (PDDA)/DNA films. In these experiments, ECL resulted from the reaction of [Ru(bpy)3](3+) with guanines of DNA. ECL produced at these thin-film electrodes was linear with respect to [Ru(bpy)3](2+) concentration from 180 to 800 μM. These studies provide the first demonstration of ECL measurements obtained using a 3D-printed closed-channel fluidic device platform. The affordable, high-resolution 3D printer used in these studies enables easy, fast, and adaptable prototyping of fluidic devices capable of incorporating electrodes for measuring ECL.

  1. Three-dimensional ordered macroporous platinum-based electrode for methanol oxidation

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, three-dimensional ordered macroporous platinum catalysts with high real surface area were synthesized using the inverted colloidal crystals template technique and have been employed for the electrooxidation of methanol. The morphology and electrocatalytic behavior of the porous Pt electrodes were investigated with atomic force microscopy and electrochemical techniques. For the same amount of Pt deposited, the real surface areas of the electrodes are 9.16 and 8.00 cm2 for the porous electrodes with pore size of 320 and 500 nm respectively, which are more than 5 times larger than the directly deposited Pt electrode (1.4 cm2). The pore size effect on the methanol electrooxidation was investigated by testing low concentration solution of methanol and porous materials with different pore sizes. The synthesized macroporous Pt electrode shows high stability toward the electrooxidation of methanol and is promising for the direct methanol fuel cell.

  2. Electric power generation by a submersible microbial fuel cell equipped with a membrane electrode assembly

    DEFF Research Database (Denmark)

    Min, Booki; Poulsen, Finn Willy; Thygesen, Anders

    2012-01-01

    , the maximum power density was 631mW/m2 at current density of 1772mA/m2 at 82Ω. With 180-Ω external resistance, one set of the electrodes on the same side could generate more power density of 832±4mW/m2 with current generation of 1923±4mA/m2. The anode, inclusive a biofilm behaved ohmic, whereas a Tafel type...... behavior was observed for the oxygen reduction. The various impedance contributions from electrodes, electrolyte and membrane were analyzed and identified by electrochemical impedance spectroscopy. Air flow rate to the cathode chamber affected microbial voltage generation, and higher power generation......Membrane electrode assemblies (MEAs) were incorporated into the cathode chamber of a submersible microbial fuel cell (SMFC). A close contact of the electrodes could produce high power output from SMFC in which anode and cathode electrodes were connected in parallel. In polarization test...

  3. Advanced boundary electrode modeling for tES and parallel tES/EEG

    CERN Document Server

    Agsten, Britte; Pursiainen, Sampsa; Wolters, Carsten H

    2016-01-01

    This paper explores advanced electrode modeling in the context of separate and parallel transcranial electrical stimulation (tES) and electroencephalography (EEG) measurements. We focus on boundary condition based approaches that do not necessitate adding auxiliary elements, e.g. sponges, to the computational domain. In particular, we investigate the complete electrode model (CEM) which incorporates a detailed description of the skin-electrode interface including its contact surface, impedance and normal current distribution. The CEM can be applied for both tES and EEG electrodes which is advantageous when a parallel system is used. In comparison to the CEM, we test two important reduced approaches: the gap model (GAP) and the point electrode model (PEM). We aim to find out the differences of these approaches for a realistic numerical setting based on the stimulation of the auditory cortex. The results obtained suggest, among other things, that GAP and GAP/PEM are sufficiently accurate for the practical appli...

  4. A printed, dry electrode Frank configuration vest for ambulatory vectorcardiographic monitoring

    Science.gov (United States)

    Paul, Gordon; Torah, Russel; Beeby, Steve; Tudor, John

    2017-02-01

    This paper describes the design and fabrication of a screen printed network of bio-potential measurement electrodes on a garment, in this case a vest. The electrodes are placed according to the Frank configuration, which allows monitoring of the electrical behavior of the heart in three spatial orientations. The vest is designed to provide stable contact pressure on the electrodes. The electrodes are fabricated from stencil printed carbon loaded rubber and are connected by screen printed silver polymer conductive tracks to an array of vias, which form an electrical connection to the other side of the textile. The vest is tested and compared to Frank configuration recordings that were obtained using standard self-adhesive ECG electrodes. The vest was successfully used to obtain Frank configuration recordings with minimal baseline drift. The vest is fabricated using only technologies found in standard textile production lines and can be used with a reduced setup effort compared to clinical 12-lead examinations.

  5. Novel active comb-shaped dry electrode for EEG measurement in hairy site.

    Science.gov (United States)

    Huang, Yan-Jun; Wu, Chung-Yu; Wong, Alice May-Kuen; Lin, Bor-Shyh

    2015-01-01

    Electroencephalography (EEG) is an important biopotential, and has been widely applied in clinical applications. The conventional EEG electrode with conductive gels is usually used for measuring EEG. However, the use of conductive gel also encounters with the issue of drying and hardening. Recently, many dry EEG electrodes based on different conductive materials and techniques were proposed to solve the previous issue. However, measuring EEG in the hairy site is still a difficult challenge. In this study, a novel active comb-shaped dry electrode was proposed to measure EEG in hairy site. Different form other comb-shaped or spike-shaped dry electrodes, it can provide more excellent performance of avoiding the signal attenuation, phase distortion, and the reduction of common mode rejection ratio. Even under walking motion, it can effectively acquire EEG in hairy site. Finally, the experiments for alpha rhythm and steady-state visually evoked potential were also tested to validate the proposed electrode.

  6. Cell dialysis by sharp electrodes can cause nonphysiological changes in neuron properties.

    Science.gov (United States)

    Hooper, Scott L; Thuma, Jeffrey B; Guschlbauer, Christoph; Schmidt, Joachim; Büschges, Ansgar

    2015-08-01

    We recorded from lobster and leech neurons with two sharp electrodes filled with solutions often used with these preparations (lobster: 0.6 M K2SO4 or 2.5 M KAc; leech: 4 M KAc), with solutions approximately matching neuron cytoplasm ion concentrations, and with 6.5 M KAc (lobster, leech) and 0.6 M KAc (lobster). We measured membrane potential, input resistance, and transient and sustained depolarization-activated outward current amplitudes in leech and these neuron properties and hyperpolarization-activated current time constant in lobster, every 10 min for 60 min after electrode penetration. Neuron properties varied with electrode fill. For fills with molarities ≥2.5 M, neuron properties also varied strongly with time after electrode penetration. Depending on the property being examined, these variations could be large. In leech, cell size also increased with noncytoplasmic fills. The changes in neuron properties could be due to the ions being injected from the electrodes during current injection. We tested this possibility in lobster with the 2.5 M KAc electrode fill by making measurements only 10 and 60 min after penetration. Neuron properties still changed, although the changes were less extreme. Making measurements every 2 min showed that the time-dependent variations in neuron properties occurred in concert with each other. Neuron property changes with high molarity electrode-fill solutions were great enough to decrease neuron firing strongly. An experiment with (14)C-glucose electrode fill confirmed earlier work showing substantial leak from sharp electrodes. Sharp electrode work should thus be performed with cytoplasm-matched electrode fills.

  7. Basic characteristics of quartz crystal sensor with interdigitated electrodes

    Directory of Open Access Journals (Sweden)

    Hiroshi Muramatsu

    2016-03-01

    Full Text Available This paper describes basic characteristics of the quartz crystal sensor with interdigitated electrodes (IDE quartz crystal sensor which is for simultaneous monitoring of mass, viscosity, conductivity and dielectric changes of liquids or thin films. As the IDE quartz crystal sensor has three terminals for a pair of IDEs on the one side and a counter electrode on the other side, the resonance properties have been analyzed using the electrical equivalent circuit models and measured experimentally for all connecting types of electrode pairs. The IDE quartz crystal has shown clear resonance curves for calculating the resonance frequency and resonance resistance values as well as normal quartz crystal in the air and in contact with liquid. Small shifts in the resonance frequency and resonance resistance depending on the connecting types have been obtained and analyzed using the equivalent circuit models. We have found the integrated quartz crystal and IDE sensors could be monitored simultaneously by only one impedance analyzer. Finally, two types of measuring systems have been demonstrated for continuous measuring methods.

  8. Mines and human casualties: a robotics approach toward mine clearing

    Science.gov (United States)

    Ghaffari, Masoud; Manthena, Dinesh; Ghaffari, Alireza; Hall, Ernest L.

    2004-10-01

    An estimated 100 million landmines which have been planted in more than 60 countries kill or maim thousands of civilians every year. Millions of people live in the vast dangerous areas and are not able to access to basic human services because of landmines" threats. This problem has affected many third world countries and poor nations which are not able to afford high cost solutions. This paper tries to present some experiences with the land mine victims and solutions for the mine clearing. It studies current situation of this crisis as well as state of the art robotics technology for the mine clearing. It also introduces a survey robot which is suitable for the mine clearing applications. The results show that in addition to technical aspects, this problem has many socio-economic issues. The significance of this study is to persuade robotics researchers toward this topic and to peruse the technical and humanitarian facets of this issue.

  9. Study on application of optical clearing technique in skin diseases

    Science.gov (United States)

    Shan, Hao; Liang, Yanmei; Wang, Jingyi; Li, Yan

    2012-11-01

    So far, the study of the optical clearing is almost always about healthy tissue. However, the ultimate goal is to detect diseases for clinical application. Optical clearing on diseased skins is explored. The effect is evaluated by applying a combined liquid paraffin and glycerol mixed solution on several kinds of diseased skins in vitro. Scanning experiments from optical coherence tomography show that it has different effects among fibroma, pigmented nevus, and seborrheic keratosis. Based on the results, we conclude that different skin diseases have different compositions and structures, and their optical parameters and biological characteristics should be different, which implies that the optical clearing technique may have selectivity and may not be suitable for all kinds of skin diseases.

  10. Diagnosis of clear sky ultraviolet radiation for Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Lemus Deschamps, L. [Bureau of Meteorology Research Centre (Australia); Galindo, I.; Solano, R.; Elizalde, A.T.; Fonseca, J. [Centro Universitario de Investigaciones en Ciencias del Ambiente, University of Colima (Mexico)

    2002-07-01

    A discrete-ordinate radiative transfer model is employed to develop a regional clear sky ultraviolet (UV) diagnosis system. The clear sky UV radiation, weighted by the spectral sensitivity of human skin is calculated using the Total Ozone Mapping Spectrometer (TOMS) data sets. Examples of the geographical clear sky UV Index distributions are presented and the model results are compared with surface UV measurements from University of Colima for 1999. [Spanish] Utilizando un modelo de transferencia de radiacion de ordenadas discretas se desarrolla un sistema para el diagnostico de la distribucion de radiacion ultravioleta para cielo despejado en la Republica Mexicana. La radiacion para cielo despejado se obtiene utilizando la respuesta espectral de la piel humana y los datos de satelite de ozono total registrados por el espectrometro TOMS. Se presentan ejemplos del Indice de radiacion ultravioleta (UV Index) calculados con el modelo y se comparan con las mediciones en superficie obtenidas en la Universidad de Colima durante 1999.

  11. Clear cell colitis: A form of microscopic colitis in children

    Institute of Scientific and Technical Information of China (English)

    Jan J(o)zefczuk; Bogdan Marian Wozniewicz

    2008-01-01

    AIM: To describe a new clinical and pathological subtype of microscopic colitis in children.METHODS: A selected group of children with abdominal pain, constipation and/or diarrhoea showing discrete or no macroscopic abnormalities on endoscopy was described.RESULTS: Multiple biopsies of colon showed large mononuclear clear cells in lamina propria of mucous membrane provided that good quality histological sections were performed and observed under a higher magnification. Otherwise, they could be misinterpreted as artefacts. Their presence in routine histology might suggest a systemic storage disease (Whipple's disease), and neuronal intestine dysplasia.Using immunohistochemical staining and electron microscopy we confirmed their origin from CD68 positive mononuclear macrophages.CONCLUSION: The presence of large clear cells is a constant microscopic feature. Failure of transient large bowel stationary macrophages plays a role in the pathogenesis of this benign microscopic clear cell colitis,sometimes coexisting with allergy.

  12. Rodent model for assessing the long term safety and performance of peripheral nerve recording electrodes

    Science.gov (United States)

    Vasudevan, Srikanth; Patel, Kunal; Welle, Cristin

    2017-02-01

    Objective. In the US alone, there are approximately 185 000 cases of limb amputation annually, which can reduce the quality of life for those individuals. Current prosthesis technology could be improved by access to signals from the nervous system for intuitive prosthesis control. After amputation, residual peripheral nerves continue to convey motor signals and electrical stimulation of these nerves can elicit sensory percepts. However, current technology for extracting information directly from peripheral nerves has limited chronic reliability, and novel approaches must be vetted to ensure safe long-term use. The present study aims to optimize methods to establish a test platform using rodent model to assess the long term safety and performance of electrode interfaces implanted in the peripheral nerves. Approach. Floating Microelectrode Arrays (FMA, Microprobes for Life Sciences) were implanted into the rodent sciatic nerve. Weekly in vivo recordings and impedance measurements were performed in animals to assess performance and physical integrity of electrodes. Motor (walking track analysis) and sensory (Von Frey) function tests were used to assess change in nerve function due to the implant. Following the terminal recording session, the nerve was explanted and the health of axons, myelin and surrounding tissues were assessed using immunohistochemistry (IHC). The explanted electrodes were visualized under high magnification using scanning electrode microscopy (SEM) to observe any physical damage. Main results. Recordings of axonal action potentials demonstrated notable session-to-session variability. Impedance of the electrodes increased upon implantation and displayed relative stability until electrode failure. Initial deficits in motor function recovered by 2 weeks, while sensory deficits persisted through 6 weeks of assessment. The primary cause of failure was identified as lead wire breakage in all of animals. IHC indicated myelinated and unmyelinated axons

  13. Tropospheric haze and colors of the clear daytime sky.

    Science.gov (United States)

    Lee, Raymond L

    2015-02-01

    To casual observers, haze's visible effects on clear daytime skies may seem mundane: significant scattering by tropospheric aerosols visibly (1) reduces the luminance contrast of distant objects and (2) desaturates sky blueness. However, few published measurements of hazy-sky spectra and chromaticities exist to compare with these naked-eye observations. Hyperspectral imaging along sky meridians of clear and hazy skies at one inland and two coastal sites shows that they have characteristic colorimetric signatures of scattering and absorption by haze aerosols. In addition, a simple spectral transfer function and a second-order scattering model of skylight reveal the net spectral and colorimetric effects of haze.

  14. Clear cell odontogenic carcinoma of maxilla: A diagnostic challenge

    Directory of Open Access Journals (Sweden)

    Fouzia Siraj

    2016-01-01

    Full Text Available Clear cell odontogenic carcinoma (CCOC is a rare odontogenic tumor which occurs mostly in the mandible. It is primarily seen in fifth to seventh decades with a female predilection. We report a case of CCOC in the maxillary arch of a 66-year-old woman. Morphologic examination along with histochemical and immunohistochemical markers led to the establishment of the diagnosis. It is important to diagnose this entity and differentiate it from other clear cell tumors in the head and neck region as it is a locally aggressive tumor with a propensity for regional, nodal, and distant metastasis.

  15. Treating refinery wastewaters in microbial fuel cells using separator electrode assembly or spaced electrode configurations

    KAUST Repository

    Zhang, Fang

    2014-01-01

    The effectiveness of refinery wastewater (RW) treatment using air-cathode, microbial fuel cells (MFCs) was examined relative to previous tests based on completely anaerobic microbial electrolysis cells (MECs). MFCs were configured with separator electrode assembly (SEA) or spaced electrode (SPA) configurations to measure power production and relative impacts of oxygen crossover on organics removal. The SEA configuration produced a higher maximum power density (280±6mW/m2; 16.3±0.4W/m3) than the SPA arrangement (255±2mW/m2) due to lower internal resistance. Power production in both configurations was lower than that obtained with the domestic wastewater (positive control) due to less favorable (more positive) anode potentials, indicating poorer biodegradability of the RW. MFCs with RW achieved up to 84% total COD removal, 73% soluble COD removal and 92% HBOD removal. These removals were higher than those previously obtained in mini-MEC tests, as oxygen crossover from the cathode enhanced degradation in MFCs compared to MECs. © 2013 Elsevier Ltd.

  16. Fabrication of interdigitated electrodes by inkjet printing technology for apllication in ammonia sensing

    Science.gov (United States)

    Dam Le, Duy; Nhien Nguyen, Thi Ngoc; Chanh Tin Doan, Duc; Dung Dang, Thi My; Chien Dang, Mau

    2016-06-01

    In this paper interdigitated electrodes for gas sensors were fabricated by inkjet printing technology. Silver electrodes were inkjet printed on Si/SiO2 substrates instead of traditional photolithography method. The inkjet printing parameters to obtain desired dimensions, thickness of the electrodes and distance between the interdigitated electrodes were optimized in this study. The fabricated interdigitated silver electrodes were tested for application in ammonia gas sensors. Conductive polyaniline (PANI) layer was coated on the silver interdigitated electrodes by drop-coating. Ammonia detection of the PANI-coated chips was characterized with a gas measurement system in which humidity and ammonia concentrations were well-controlled. The electrical conductivity of the PANI films coated on the electrodes was measured when the PANI films were exposed to nitrogen and ammonia. The conductivity of the PANI films decreased significantly due to the deprotonation process of PANI upon ammonia expodure. The recovery time was about 15 min by heating up the polymer chip at 60 °C. The results showed that the silver electrodes fabricated by inkjet printing technique could be used as a sensor platform for ammonia detection.

  17. A serial dual-electrode detector based on electrogenerated bromine for capillary electrophoresis.

    Science.gov (United States)

    Du, Fuying; Cao, Shunan; Fung, Ying-Sing

    2014-12-01

    A new serial dual-electrode detector for CE has been designed and fabricated for postcolumn reaction detection based on electrogenerated bromine. A coaxial postcolumn reactor was employed to introduce bromide reagent and facilitate the fabrication of upstream generation electrode by simply sputtering Pt film onto the outer surface of the separation capillary. Bromide introduced could be efficiently converted to bromine at this Pt film electrode and subsequently detected by the downstream Pt microdisk detection electrode. Analytes that react with bromine could be determined by the decrease of bromine reduction current at the downstream electrode resulting from the reaction between analytes and bromine. The effects of serial dual-electrode detector working conditions including electrode potentials, bromide flow rate, and bromide concentration on analytical performance were investigated using glutathione (GSH) and glutathione disulfide (GSSG) as test analytes. Under the optimal conditions, detection limits down to 0.16 μM for GSH and 0.14 μM for GSSG (S/N = 3) as well as linear working ranges of two orders of magnitude for GSH and GSSG were achieved. Furthermore, the separation efficiency obtained by our dual-electrode detector design was greatly improved compared with previous reported design. The developed method has been successfully applied to determine the GSH and GSSG impurity in commercial GSH supplement.

  18. Effect of electrode material and design on sensitivity and selectivity for high temperature impedancemetric NOx sensors

    Energy Technology Data Exchange (ETDEWEB)

    Woo, L Y; Glass, R S; Novak, R F; Visser, J H

    2009-09-23

    Solid-state electrochemical sensors using two different sensing electrode compositions, gold and strontium-doped lanthanum manganite (LSM), were evaluated for gas phase sensing of NO{sub x} (NO and NO{sub 2}) using an impedance-metric technique. An asymmetric cell design utilizing porous YSZ electrolyte exposed both electrodes to the test gas (i.e., no reference gas). Sensitivity to less than 5 ppm NO and response/recovery times (10-90%) less than 10 s were demonstrated. Using an LSM sensing electrode, virtual identical sensitivity towards NO and NO{sub 2} was obtained, indicating that the equilibrium gas concentration was measured by the sensing electrode. In contrast, for cells employing a gold sensing electrode the NO{sub x} sensitivity varied depending on the cell design: increasing the amount of porous YSZ electrolyte on the sensor surface produced higher NO{sub 2} sensitivity compared to NO. In order to achieve comparable sensitivity for both NO and NO{sub 2}, the cell with the LSM sensing electrode required operation at a lower temperature (575 C) than the cell with the gold sensing electrode (650 C). The role of surface reactions are proposed to explain the differences in NO and NO{sub 2} selectivity using the two different electrode materials.

  19. LiNi0.5Mn1.5O4-based composite electrodes with improved properties prepared by a slurry spray deposition process

    Science.gov (United States)

    Yu, Ran; Sun, Yi; Zou, Bang-Kun; Deng, Miao-Miao; Xie, Jing-Ying; Chen, Chun-Hua

    2017-02-01

    A slurry spray deposition (SSD) process is utilized to prepare a LiNi0.5Mn1.5O4-based composite electrode supported on an aluminum foil. The spray deposition process is performed at room temperature through the atomization and deposition of the composite electrode slurry. A comparative LiNi0.5Mn1.5O4-based composite electrode is also prepared by the traditional blade coating method. The surface morphology and elements mapping of the electrodes are measured by scanning electron microscopy and energy-dispersive X-ray spectroscopy, respectively. The adhesion between the composite electrode layers and the aluminum foil is also tested. A parallel evaluation on the mechanical and electrochemical performances of the two kinds of electrodes is conducted. The SSD electrode exhibits improved adhesion, cycling stability and rate capability. Therefore, the SSD process is an effective way to fabricate advanced electrodes for high performance lithium ion cells.

  20. Clearing the Cosmic Fog - The Most Distant Galaxy Ever Measured

    Science.gov (United States)

    2010-10-01

    distances to such faint and remote objects is an enormous challenge and can only reliably be done using spectroscopy from very large ground-based telescopes [4], by measuring the redshift of the galaxy's light. Matt Lehnert takes up the story: "After the announcement of the candidate galaxies from Hubble we did a quick calculation and were excited to find that the immense light collecting power of the VLT, when combined with the sensitivity of the infrared spectroscopic instrument, SINFONI, and a very long exposure time might just allow us to detect the extremely faint glow from one of these remote galaxies and to measure its distance." On special request to ESO's Director General they obtained telescope time on the VLT and observed a candidate galaxy called UDFy-38135539 [5] for 16 hours. After two months of very careful analysis and testing of their results, the team found that they had clearly detected the very faint glow from hydrogen at a redshift of 8.6, which makes this galaxy the most distant object ever confirmed by spectroscopy. A redshift of 8.6 corresponds to a galaxy seen just 600 million years after the Big Bang. Co-author Nicole Nesvadba (Institut d'Astrophysique Spatiale) sums up this work, "Measuring the redshift of the most distant galaxy so far is very exciting in itself, but the astrophysical implications of this detection are even more important. This is the first time we know for sure that we are looking at one of the galaxies that cleared out the fog which had filled the very early Universe." One of the surprising things about this discovery is that the glow from UDFy-38135539 seems not to be strong enough on its own to clear out the hydrogen fog. "There must be other galaxies, probably fainter and less massive nearby companions of UDFy-38135539, which also helped make the space around the galaxy transparent. Without this additional help the light from the galaxy, no matter how brilliant, would have been trapped in the surrounding hydrogen fog and we

  1. iElectrodes: A Comprehensive Open-Source Toolbox for Depth and Subdural Grid Electrode Localization

    Science.gov (United States)

    Blenkmann, Alejandro O.; Phillips, Holly N.; Princich, Juan P.; Rowe, James B.; Bekinschtein, Tristan A.; Muravchik, Carlos H.; Kochen, Silvia

    2017-01-01

    The localization of intracranial electrodes is a fundamental step in the analysis of invasive electroencephalography (EEG) recordings in research and clinical practice. The conclusions reached from the analysis of these recordings rely on the accuracy of electrode localization in relationship to brain anatomy. However, currently available techniques for localizing electrodes from magnetic resonance (MR) and/or computerized tomography (CT) images are time consuming and/or limited to particular electrode types or shapes. Here we present iElectrodes, an open-source toolbox that provides robust and accurate semi-automatic localization of both subdural grids and depth electrodes. Using pre- and post-implantation images, the method takes 2–3 min to localize the coordinates in each electrode array and automatically number the electrodes. The proposed pre-processing pipeline allows one to work in a normalized space and to automatically obtain anatomical labels of the localized electrodes without neuroimaging experts. We validated the method with data from 22 patients implanted with a total of 1,242 electrodes. We show that localization distances were within 0.56 mm of those achieved by experienced manual evaluators. iElectrodes provided additional advantages in terms of robustness (even with severe perioperative cerebral distortions), speed (less than half the operator time compared to expert manual localization), simplicity, utility across multiple electrode types (surface and depth electrodes) and all brain regions. PMID:28303098

  2. Nickel electrode for alkaline batteries

    Energy Technology Data Exchange (ETDEWEB)

    Charkey, A.; Januszkiewicz, S.

    1985-10-08

    A nickel electrode including a conductive support and a layer on the support including a mixture of a nickel active material and a graphite diluent containing a spinel type oxide, the spinel type oxide having the formula M/sub 2/Co/sub 2/O/sub 4/, where M/sub 2/ is Co, Ni, Mn, Fe, Cu, Zn or Cd, or combinations thereof, and having a weight which is in the range of 1-30 percent of the weight of the diluent.

  3. Progress in understanding SOFC electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Hansen, Karin Vels; Jørgensen, M.J.;

    2002-01-01

    The literature of SOFC electrode kinetics and mechanisms is full of contradicting details in case of both the SOFC anode and cathode processes. Only weak patterns may be identified. One interpretation is that each of the reported data sets reflects a laboratory specific nature of each...... and synthesis procedures. The paper deals with the available evidence and gives some possible explanations of observed phenomena, e.g. of the various reported effects of water and of the temperature dependence of H/D isotope effect on the SOFC anode. (C) 2002 Elsevier Science B.V. All rights reserved....

  4. Skin optical clearing for improvement of laser tattoo removal

    Science.gov (United States)

    Genina, Elina A.; Bashkatov, Alexey N.; Gavrilova, Anna A.; Pravdin, Alexander B.; Tuchin, Valery V.; Yaroslavsky, Ilya V.; Altshuler, Gregory B.

    2007-06-01

    The removal of tattoo pigments by laser energy is effected through a process of selective photothermolysis. Dehydration and optical immersion based on refractive index matching of scattering centers with that of surrounding matter through introduction of an exogenous index-matching agent can improve laser tattoo removal by providing increased efficiency of laser delivery to embedded ink particles and enabling the use of shorter wavelength visible lasers more effective on certain inks. Effectiveness of a method of accelerating penetration of the index-matching compounds by enhancing skin permeability through creating a lattice of micro-zones of limited thermal damage in the stratum corneum was studied. As optical clearing agents 100% and 88%-aqueous glycerol solutions were used. The effect of stratum corneum perforation on the rate of the immersion clearing of skin was studied. Dynamics of refractive index alteration of glycerol solution during its interaction with skin samples was monitored. Improvement of tattoo visualization was observed. The results of the experiments have shown that the lattice of island damage method the is effective for transepidermal delivery of optical clearing agents and could be used successfully in in vivo conditions for the enhancement of optical clearing of treated skin area and as enabling improvement of laser tattoo removal.

  5. The Search for Durable Exterior Clear Coatings for Wood

    Directory of Open Access Journals (Sweden)

    Philip D. Evans

    2015-11-01

    Full Text Available The goal of a durable exterior clear coating has eluded generations of coatings technologists, despite long-standing desire amongst the public for such a coating. The journey towards this goal initially focused on modifications to coating formulation, but took a completely different direction when it was found that a UV-transparent silicone clear coating on wood modified with chromic acid met consumer expectations of coating durability. This finding sparked world-wide interest in wood pre-treatments as a way of enhancing the durability of clear coatings. This interest initially focused on transition metal compounds, but has now shifted in the direction of organic and inorganic photostabilizers or even more drastic pre-treatments. Pre-treatments that dimensionally stabilize wood, protect it from microbial degradation and photostabilize lignin, when combined with flexible, photostable, coatings provide the next way-stop on the journey towards achieving the goal of durable exterior clear coatings for wood. This paper reviews this journey, drawing upon our research and that of other groups who have focused on this elusive goal.

  6. 76 FR 16587 - Risk Management Requirements for Derivatives Clearing Organizations

    Science.gov (United States)

    2011-03-24

    ... COMMISSION 17 CFR Part 39 RIN 3038-AC98 Risk Management Requirements for Derivatives Clearing Organizations... Principle D (Risk Management) and would establish a related reporting requirement under Core Principle J... Exchange Act (CEA) \\4\\ to establish a comprehensive regulatory framework to reduce risk,...

  7. Clearing the Fog from the Undergraduate Course in Linear Algebra

    Science.gov (United States)

    Scott, Damon

    2007-01-01

    For over a decade it has been a common observation that a "fog" passes over the course in linear algebra once abstract vector spaces are presented. See [2, 3]. We show how this fog may be cleared by having the students translate "abstract" vector-space problems to isomorphic "concrete" settings, solve the "concrete" problem either by hand or with…

  8. 31 CFR 50.12 - Clear and conspicuous disclosure.

    Science.gov (United States)

    2010-07-01

    ... INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.12 Clear and conspicuous disclosure. (a... circumstances of the disclosure. See § 50.17 for model forms. (b)(1) Description of premium. An insurer may..., consistent with the definition of an act of terrorism as amended by the Terrorism Risk Insurance...

  9. Marketing Strategies of United Kingdom Universities during Clearing and Adjustment

    Science.gov (United States)

    Mogaji, Emmanuel

    2016-01-01

    Purpose: The clearing system in the UK enables students without a university place after exam results have been announced to find suitable vacancies, as it is important for universities to fill their vacancies as any shortfall loses them a lot of money. The purpose of this paper is to examine marketing strategies adopted by UK universities on…

  10. Clear Speech Variants: An Acoustic Study in Parkinson's Disease

    Science.gov (United States)

    Lam, Jennifer; Tjaden, Kris

    2016-01-01

    Purpose: The authors investigated how different variants of clear speech affect segmental and suprasegmental acoustic measures of speech in speakers with Parkinson's disease and a healthy control group. Method: A total of 14 participants with Parkinson's disease and 14 control participants served as speakers. Each speaker produced 18 different…

  11. Multifocal Rhizopus microsporus lung infection following brush clearing

    Directory of Open Access Journals (Sweden)

    Artsiom V. Tsyrkunou

    2014-10-01

    Full Text Available We report a case of pulmonary Rhizopus microsporus infection in a patient with untreated diabetes following brush clearing. The patient was successfully treated with a combined medical and surgical approach with complete resolution of the lung lesions and remains asymptomatic at 11-month follow-up.

  12. Seeing Clearly (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    2014-05-08

    If you’re not seeing the world as clearly as you used to, you might be among the millions of people suffering from vision impairment. In this podcast, Dr. John Crews discusses ways to take care of your eyes.  Created: 5/8/2014 by MMWR.   Date Released: 5/8/2014.

  13. 19 CFR 4.60 - Vessels required to clear.

    Science.gov (United States)

    2010-04-01

    ... contiguous country otherwise than by sea. (c) Vessels which will merely transit the Panama Canal without transacting any business there shall not be required to be cleared because of such transit. (d) In the event... hours after clearance to the port director who shall note the fact of detention on the certificate...

  14. Stabilization of insertion electrodes for lithium batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Thackeray, M. M.

    1998-09-03

    This paper discusses the techniques that are being employed to stabilize LiMn{sub 2}O{sub 4} spinel and composite Li{sub x}MnO{sub 2} positive electrodes. The critical role that spinel domains play in stabilizing these electrodes for operation at both 4 V and 3 V is highlighted. The concept of using an intermetallic electrode MM{prime} where M is an active alloying element and M{prime} is an inactive element (or elements) is proposed as an alternative negative electrode (to carbon) for lithium-ion cells. An analogy to metal oxide insertion electrodes, such as MnO{sub 2}, in which Mn is the electrochemically active ion and O is the inactive ion, is made. Performance data are given for the copper-tin electrode system, which includes the intermetallic phases eta-Cu{sub 6}Sn{sub 5} and Li{sub 2}CuSn.

  15. Secondary Ionization Coefficient of Dielectric Electrode

    Science.gov (United States)

    Kashiwagi, Yasuhide; Suzuki, Susumu; Itoh, Haruo

    Experiments for observations and stabilization of discharge paths in several electrode systems are carried out aiming at precise measurement of the secondary ionization coefficient γ of MgO film electrode. The discharge chamber is filled with Ar gas. The waveforms of the applied voltage between the electrodes and the discharge current are measured with visual observation of the discharge light. Two MgO coated electrodes are placed so that they are facing each other. For these MgO electrodes, the discharge paths take a detour, not the shortest distance. Smaller prebreakdown current pulses are observed before the breakdown. After breakdown, discontinuous discharge current is observed. Therefore, it is prepared a glass tube surrounding the discharge area. As the result, the discharge paths take a straight perpendicular for the electrode surface, and the discharge is stabilized.

  16. Lithium-aluminum-magnesium electrode composition

    Science.gov (United States)

    Melendres, Carlos A.; Siegel, Stanley

    1978-01-01

    A negative electrode composition is presented for use in a secondary, high-temperature electrochemical cell. The cell also includes a molten salt electrolyte of alkali metal halides or alkaline earth metal halides and a positive electrode including a chalcogen or a metal chalcogenide as the active electrode material. The negative electrode composition includes up to 50 atom percent lithium as the active electrode constituent and a magnesium-aluminum alloy as a structural matrix. Various binary and ternary intermetallic phases of lithium, magnesium, and aluminum are formed but the electrode composition in both its charged and discharged state remains substantially free of the alpha lithium-aluminum phase and exhibits good structural integrity.

  17. Treatment results and prognostic factors of clear cell ovarian carcinomas and ovarian carcinomas with clear cell component

    Directory of Open Access Journals (Sweden)

    M. D. Ahmedova

    2012-01-01

    Full Text Available The most important prognostic factors for clear cell carcinoma (CCC are clinical and morphological signs and clinical stage of the disease. Analyses of 5-year survival in patients with I stage of CCC is 69 %, in II stage – 55 %, in III stage – 14 % and in IV stage – 4 % patients. We analyzed distant results of treatment of 71 patients with CCC and of 25 patients with mixed malignant ovaries neoplasm with obligatory clear cell component taking into consideration main clinical and morphological sings of disease. On the base of performed reseal we revealed that morphological structure of the tumors and stage of the disease exerted heist influence on the exponent of survival of the patients with clear CCC ovaries neoplasm. Besides, there is a correlation between exponent of patients’ survival and radicalized of surgery, character of tumor growth, differentiation degree, cell anaplasia and mitotic activity of tumor cells.

  18. Spontaneous adsorption and electrochemical behaviour of safranine O at electrochemically activated glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Abdessamad, NourElHouda [Laboratoire de Chimie Analytique et d' Electrochimie, Institut National des Sciences Appliquees et de Technologie, Centre Urbain Nord B.P. No. 676, 1080 Tunis Cedex (Tunisia); Adhoum, Nafaa, E-mail: Nafaa.adhoum@insat.rnu.tn [Laboratoire de Chimie Analytique et d' Electrochimie, Institut National des Sciences Appliquees et de Technologie, Centre Urbain Nord B.P. No. 676, 1080 Tunis Cedex (Tunisia)

    2009-08-15

    The adsorption behaviour of safranine O (SO) at electrochemically pretreated glassy carbon electrodes has been studied. It was found that SO adsorption depended on the properties of the electrode surface, as determined by the nature and duration of the activation step. It was noticed that SO was adsorbed spontaneously and strongly on the surface of anodically pretreated electrode. The electrochemical behaviour of the modified electrode was investigated in H{sub 2}SO{sub 4} (0.25 M) using cyclic voltammetry (CV). A reversible two electron, two proton wave was observed at -180 mV vs. SCE and the formal potential was found to be decreasing upon increasing the solution pH (-56.8 mV pH{sup -1}). The modified electrode exhibited good stability on repeated scanning between -500 and 200 mV vs. SCE, causing only 5% decrease in the peak height after 100 cycles at a scan rate of 20 mV s{sup -1}. The surface coverage was calculated to be 0.812 nmol cm{sup -2} and the electron transfer rate constant (k{sub s}{sup 0}=1.45s{sup -1}) and transfer coefficient ({alpha} = 0.43) for the adsorbed SO were evaluated using the Laviron method. The modified electrode clearly showed good electrocatalytic ability for oxygen reduction to H{sub 2}O{sub 2}.

  19. Clear cell ovarian cancer and endometriosis: is there a relationship?

    Directory of Open Access Journals (Sweden)

    Maria Szubert

    2016-07-01

    Full Text Available Introduction: Ovarian clear cell carcinoma is a rare type of ovarian cancer. In recent years, issues of the common genetic origin of endometriosis and ovarian clear cell carcinoma have been raised. Aim of this study was to evaluate the prevalence of this type of cancer, risk factors, prognosis and its potential aetiological association with endometriosis. Material and methods: In a retrospective study, we analysed histopathological data of patients operated in the First Department of Gynaecology and Obstetrics (MU, Lodz due to ovarian cancer in 2004-2014. Among the 394 patients operated on for ovarian cancer, clear cell carcinoma was found in 0.02% (9/394. Menstrual history, parity, comorbidities, data from physical examination, operational protocols and histopathological diagnoses were analysed. Follow-up was obtained from 77.8% of patients. Statistical analysis was performed using Microsoft Excel 2013. Results: The mean age of patients at diagnosis was 57.6 years; the BMI in the study group was 27.2; the majority of patients were multiparous (77.8%. Clear cell carcinoma was detected mostly at stage Ia (n = 4. The concentration of Ca125 in the study group had an average of 142.75 U/ml and a median of 69.3 U/ml. The coexistence of endometriosis could not be clinically or histologically confirmed amongst our patients. The most common comorbidity in the study group was hypertension. Conclusions : In our clinical material, ovarian clear cell carcinoma is a rare histopathological specimen with a prognostic value comparable to that of serous ovarian cancer. Due to the rarity of this histopathological subtype, proving a cause-and-effect relationship between it and endometriosis can only be elucidated through statistical studies of the entire population.

  20. Infectivity of Arbuscular Mycorrhizal Fungi in Naturally Regenerating, Unmanaged and Clear-Cut Beech Forests

    Institute of Scientific and Technical Information of China (English)

    I.CLOSA; N.GOICOECHEA

    2011-01-01

    Clear-cutting, a management practice applied to many beech forests in the North of Spain, modifies microclimate and, consequently,the composition of the understory plant community in the disturbed areas. The objectives of this study were to assess if changes in the understory vegetation caused by altered light microclimate after clear-cutting affect the infectivity of arbuscular mycorrhizal fungi (AMF) on herbaceous plant species in beech (Fagus sylvatica L.) forests naturally regenerating from clear-cutting and to test if the use of bioassays for studying the infectivity of native AMF could provide aseful information to improve the management of clear-cut areas.Three nearby beech forests in northwest Navarra, Spain, a region in the northwest part of the Pyrenees, were selected: an unmanaged forest, a forest clear-cut in 1996, and another forest clear-cut in 2001. High stem density in the forest clear-cut in 1996 (44 000 trees ha-1) attenuated photosynthetic active radiation (PAR) and impaired the growth of herbaceous species within the ecosystem. The percentage of AMF colonization of plants in bioassays performed on soil samples collected from the forest clear-cut in 1996 was always lower than 10%. In the forest clear-cut in 2001, where soil was covered by perennial grasses, PAR was high and thc infectivity of native AMF achieved minimum values in spring and autumn and a maximum value in summer. In contrast, the infectivity of native AMF in the umnanaged forest remained similar across the seasons. Our results demonstrated that changes in the composition of understory vegetation within beech forests strongly affected the infectivity of native AMF in clear-cut areas and suggested that the assessment of the infectivity of native AMF through bioassays could provide helpful information for planning either the removal of overstory when the tree density is so high that it impairs the correct development of herbaceous species or the plantation of new sesdlings when high

  1. Plasma spark discharge reactor and durable electrode

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young I.; Cho, Daniel J.; Fridman, Alexander; Kim, Hyoungsup

    2017-01-10

    A plasma spark discharge reactor for treating water. The plasma spark discharge reactor comprises a HV electrode with a head and ground electrode that surrounds at least a portion of the HV electrode. A passage for gas may pass through the reactor to a location proximate to the head to provide controlled formation of gas bubbles in order to facilitate the plasma spark discharge in a liquid environment.

  2. Electrocatalytic activity of bismuth doped silver electrodes

    CERN Document Server

    Amjad, M

    2002-01-01

    Investigation of redox reactions on silver, and bismuth doped silver electrodes in aqueous KOH solutions, by using potentiostatic steady-state polarization technique, has been carried out. The redox wave potential and current displacements along with multiplicity of the latter have been examined. These electrodes were employed for the oxidation of organic molecules such as ethylamine in alkaline media. Subsequently, these electrodes were ranked with respect to their activity for the redox reactions. (author)

  3. Semiconductor devices having a recessed electrode structure

    Science.gov (United States)

    Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

    2015-05-26

    An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

  4. Semiconductor electrode with improved photostability characteristics

    Science.gov (United States)

    Frank, Arthur J.

    1987-01-01

    An electrode is disclosed for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode includes a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

  5. Solid oxide electrode kinetics in light of in situ surface studies

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg

    2014-01-01

    The combination of in situ and in particular in operando characterization methods such as electrochemical impedance spectroscopy (EIS) on both technical and model electrode are well known ways to gain some practical insight in electrode reaction kinetics. Yet, is has become clear that in spite...... couple of decades, but recent in situ - or even better - in operando surface measurements such as high temperature scanning probe measurements and Raman spectroscopy have proven very valuable in obtaining new data that can support the interpretation of EIS and current – voltage (i-V) measurements...

  6. Integration of colloidal silicon nanocrystals on metal electrodes in single-electron transistor

    Science.gov (United States)

    Higashikawa, Yasuhiro; Azuma, Yasuo; Majima, Yutaka; Kano, Shinya; Fujii, Minoru

    2016-11-01

    We develop a facile process to integrate colloidal silicon nanocrystals (Si NCs) with metal electrodes in a single-electron transistor by self-assembly. Gold (Au) surface is modified by an amine-terminated self-assembled monolayer to have a positive potential. All-inorganic boron (B) and phosphorus (P) codoped Si NCs, with a negative surface potential and size-controllability, are selectively adsorbed on an amine-terminated Au surface by electrostatic attraction. We demonstrate the fabrication of SETs consisting of electroless-plated Au nanogap electrodes and codoped Si NCs using this process and observation of clear Coulomb diamonds at 9 K.

  7. Embedded silver PDMS electrodes for single cell electrical impedance spectroscopy

    Science.gov (United States)

    Wei, Yuan; Xu, Zhensong; Cachia, Mark A.; Nguyen, John; Zheng, Yi; Wang, Chen; Sun, Yu

    2016-09-01

    This paper presents a microfluidic device with wide channels and embedded AgPDMS electrodes for measuring the electrical properties of single cells. The work demonstrates the feasibility of using a large channel design and embedded electrodes for impedance spectroscopy to circumvent issues such as channel clogging and limited device re-usability. AgPDMS electrodes were formed on channel sidewalls for impedance detection and cell electrical properties measurement. Equivalent circuit models were used to interpret multi-frequency impedance data to quantify each cell’s cytoplasm conductivity and specific membrane capacitance. T24 cells were tested to validate the microfluidic system and modeling results. Comparisons were then made by measuring two leukemia cell lines (AML-2 and HL-60) which were found to have different cytoplasm conductivity values (0.29  ±  0.15 S m-1 versus 0.47  ±  0.20 S m-1) and specific membrane capacitance values (41  ±  25 mF m-2 versus 55  ±  26 mF m-2) when the cells were flown through the wide channel and measured by the AgPDMS electrodes.

  8. The effect of environmental degradation on the characterisation of automotive clear coats by infrared spectroscopy.

    Science.gov (United States)

    van der Pal, Karin J; Sauzier, Georgina; Maric, Mark; van Bronswijk, Wilhelm; Pitts, Kari; Lewis, Simon W

    2016-02-01

    This paper presents a study into the chemical changes occurring within automotive clear coats as a result of environmental weathering, and their potential effect upon the characterisation of samples using infrared spectroscopy combined with chemometric modelling. Testing of three samples, collected from separate vehicles, exposed to the outside environment revealed no changes in model predictions over a 175 day period; however, incorrect predictions were observed following 435 days of exposure. Inspection of the corresponding infrared spectra revealed that these changes were likely due to the hydrolysis and photodegradation of polymer chains present in the clear coat, which were not observed in samples stored away from the outside environment over a one-year period. Analysis of previously weathered samples using synchrotron infrared microscopy found these changes occurred in a top-down fashion rather than within the bulk of the clear coat. This indicates that although weathering may affect the surface characterisation of clear coats over time, the targeting of deeper portions of the clear coat layer may still provide useful information as to the identity of the vehicle.

  9. Solvent-Free Manufacturing of Electrodes for Lithium-ion Batteries

    Science.gov (United States)

    Ludwig, Brandon; Zheng, Zhangfeng; Shou, Wan; Wang, Yan; Pan, Heng

    2016-03-01

    Lithium ion battery electrodes were manufactured using a new, completely dry powder painting process. The solvents used for conventional slurry-cast electrodes have been completely removed. Thermal activation time has been greatly reduced due to the time and resource demanding solvent evaporation process needed with slurry-cast electrode manufacturing being replaced by a hot rolling process. It has been found that thermal activation time to induce mechanical bonding of the thermoplastic polymer to the remaining active electrode particles is only a few seconds. Removing the solvent and drying process allows large-scale Li-ion battery production to be more economically viable in markets such as automotive energy storage systems. By understanding the surface energies of various powders which govern the powder mixing and binder distribution, bonding tests of the dry-deposited particles onto the current collector show that the bonding strength is greater than slurry-cast electrodes, 148.8 kPa as compared to 84.3 kPa. Electrochemical tests show that the new electrodes outperform conventional slurry processed electrodes, which is due to different binder distribution.

  10. FUEL CELL ELECTRODES FOR ACID MEDIA

    Science.gov (United States)

    fuel cell electrodes for acid media. Activated carbon electrodes were prepared, wetproofed with paraffin or Teflon, and catalyzed with platinum. The wetproofing agent was applied by immersion or electrodeposition and the catalyst applied by chemical decomposition of H2P+Cl6 solutions. Half cell studies with hydrogen anodes and oxygen (air) cathodes showed that electrochemical performance is essentially the same for paraffin and Teflontreated electrodes; however, the life of the Teflon-treated electrodes under equal conditions of load is greater than that for

  11. Electrode structure and methods of making same

    Energy Technology Data Exchange (ETDEWEB)

    Ruud, James Anthony; Browall, Kenneth Walter; Rehg, Timothy Joseph; Renou, Stephane; Striker, Todd-Michael

    2010-04-06

    A method of making an electrode structure is provided. The method includes disposing an electrocatalytic material on an electrode, applying heat to the electrocatalytic material to form a volatile oxide of the electrocatalytic material, and applying a voltage to the electrode to reduce the volatile oxide to provide a number of nano-sized electrocatalytic particles on or proximate to a triple phase boundary, where the number of nano-sized electrocatalytic particles is greater on or proximate to the triple phase boundary than in an area that is not on or proximate to the triple phase boundary, and where the triple phase boundary is disposed on the electrode.

  12. Carbon aerogel electrodes for direct energy conversion

    Science.gov (United States)

    Mayer, Steven T.; Kaschmitter, James L.; Pekala, Richard W.

    1997-01-01

    A direct energy conversion device, such as a fuel cell, using carbon aerogel electrodes, wherein the carbon aerogel is loaded with a noble catalyst, such as platinum or rhodium and soaked with phosphoric acid, for example. A separator is located between the electrodes, which are placed in a cylinder having plate current collectors positioned adjacent the electrodes and connected to a power supply, and a pair of gas manifolds, containing hydrogen and oxygen positioned adjacent the current collectors. Due to the high surface area and excellent electrical conductivity of carbon aerogels, the problems relative to high polarization resistance of carbon composite electrodes conventionally used in fuel cells are overcome.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  14. Charged Water Droplets can Melt Metallic Electrodes

    Science.gov (United States)

    Elton, Eric; Rosenberg, Ethan; Ristenpart, William

    2016-11-01

    A water drop, when immersed in an insulating fluid, acquires charge when it contacts an energized electrode. Provided the electric field is strong enough, the drop will move away to the opposite electrode, acquire the opposite charge, and repeat the process, effectively 'bouncing' back and forth between the electrodes. A key implicit assumption, dating back to Maxwell, has been that the electrode remains unaltered by the charging process. Here we demonstrate that the electrode is physically deformed during each charge transfer event with an individual water droplet or other conducting object. We used optical, electron, and atomic force microscopy to characterize a variety of different metallic electrodes before and after drops were electrically bounced on them. Although the electrodes appear unchanged to the naked eye, the microscopy reveals that each charge transfer event yielded a crater approximately 1 micron wide and 50 nm deep, with the exact dimensions proportional to the applied field strength. We present evidence that the craters are formed by localized melting of the electrodes via Joule heating in the metal and concurrent dielectric breakdown of the surrounding fluid, suggesting that the electrode locally achieves temperatures exceeding 3400°C. Present address: Dept. Materials Sci. Engineering, MIT.

  15. Electrode assemblies, plasma apparatuses and systems including electrode assemblies, and methods for generating plasma

    Science.gov (United States)

    Kong, Peter C; Grandy, Jon D; Detering, Brent A; Zuck, Larry D

    2013-09-17

    Electrode assemblies for plasma reactors include a structure or device for constraining an arc endpoint to a selected area or region on an electrode. In some embodiments, the structure or device may comprise one or more insulating members covering a portion of an electrode. In additional embodiments, the structure or device may provide a magnetic field configured to control a location of an arc endpoint on the electrode. Plasma generating modules, apparatus, and systems include such electrode assemblies. Methods for generating a plasma include covering at least a portion of a surface of an electrode with an electrically insulating member to constrain a location of an arc endpoint on the electrode. Additional methods for generating a plasma include generating a magnetic field to constrain a location of an arc endpoint on an electrode.

  16. Polystyrene Based Silver Selective Electrodes

    Directory of Open Access Journals (Sweden)

    Shiva Agarwal

    2002-06-01

    Full Text Available Silver(I selective sensors have been fabricated from polystyrene matrix membranes containing macrocycle, Me6(14 diene.2HClO4 as ionophore. Best performance was exhibited by the membrane having a composition macrocycle : Polystyrene in the ratio 15:1. This membrane worked well over a wide concentration range 5.0×10-6–1.0×10-1M of Ag+ with a near-Nernstian slope of 53.0 ± 1.0 mV per decade of Ag+ activity. The response time of the sensor is <15 s and the membrane can be used over a period of four months with good reproducibility. The proposed electrode works well in a wide pH range 2.5-9.0 and demonstrates good discriminating power over a number of mono-, di-, and trivalent cations. The sensor has also been used as an indicator electrode in the potentiometric titration of silver(II ions against NaCl solution. The sensor can also be used in non-aqueous medium with no significant change in the value of slope or working concentration range for the estimation of Ag+ in solution having up to 25% (v/v nonaqueous fraction.

  17. Desalination with carbon aerogel electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; Richardson, J.H.; Fix, D.V.

    1996-10-21

    An electrically regenerated electrosorption process known as carbon aerogel CDI was developed for continuously removing ionic impurities from aqueous streams. A salt solution flows in a channel formed by pairs of parallel carbon aerogel electrodes. Each electrode has a very high BET surface area and very low resistivity. After polarization, anions and cations are removed from electrolyte by the electric field and electrosorbed onto the carbon aerogel. The solution is thus separated into two streams, brine and water. Based on this, carbon aerogel CDI appears to be an energy-efficient alternative to evaporation, electrodialysis, and reverse osmosis. The energy required by this process is about QV/2, plus losses. Estimated energy requirement for sea water desalination is 18-27 Wh gal{sup -1}, depending on cell voltage and flow rate. The requirement for brackish water desalination is less, 1.2-2.5 Wh gal{sup -1} at 1600 ppM. This is assuming that stored electrical energy is reclaimed during regeneration.

  18. Evaluation of the electrode performance for PAFC by using acid absorption, acceleration and ac-impedance measurement

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang-Soo; Song, Rak-Hyun; Choi, Byung-Woo [Korea Institute of Energy Research, Taejon (Korea, Republic of)] [and others

    1996-12-31

    In PAFC, the degradation on cathode electrode caused by carbon corrosion, platinum dissolution and growth is especially severe. An acceleration test is a good technique for evaluating the degradation of electrode performance, because it does not need long time. Coleman et al used thermal cycling and on-off cycling as an acceleration test. Song et al showed that hydrogen shortage decreased the electrode performance more rapidly than that of air shortage in gas shortage test. Honji et al reported that the rate of coarsening of Pt particle is rapid in open circuit potential and this is one of major causes on the performance degradation of electrode. The cathode performance has been studied by using acid absorption, acceleration and ac-impedance measurements as functions of the polytetrafluoroethylene (PTFE) contents and sintering temperatures of the electrode.

  19. A Supplementary Clear-Sky Snow and Ice Recognition Technique for CERES Level 2 Products

    Science.gov (United States)

    Radkevich, Alexander; Khlopenkov, Konstantin; Rutan, David; Kato, Seiji

    2013-01-01

    Identification of clear-sky snow and ice is an important step in the production of cryosphere radiation budget products, which are used in the derivation of long-term data series for climate research. In this paper, a new method of clear-sky snow/ice identification for Moderate Resolution Imaging Spectroradiometer (MODIS) is presented. The algorithm's goal is to enhance the identification of snow and ice within the Clouds and the Earth's Radiant Energy System (CERES) data after application of the standard CERES scene identification scheme. The input of the algorithm uses spectral radiances from five MODIS bands and surface skin temperature available in the CERES Single Scanner Footprint (SSF) product. The algorithm produces a cryosphere rating from an aggregated test: a higher rating corresponds to a more certain identification of the clear-sky snow/ice-covered scene. Empirical analysis of regions of interest representing distinctive targets such as snow, ice, ice and water clouds, open waters, and snow-free land selected from a number of MODIS images shows that the cryosphere rating of snow/ice targets falls into 95% confidence intervals lying above the same confidence intervals of all other targets. This enables recognition of clear-sky cryosphere by using a single threshold applied to the rating, which makes this technique different from traditional branching techniques based on multiple thresholds. Limited tests show that the established threshold clearly separates the cryosphere rating values computed for the cryosphere from those computed for noncryosphere scenes, whereas individual tests applied consequently cannot reliably identify the cryosphere for complex scenes.

  20. Portable Bioimpedance Spectroscopy device and textile electrodes for mobile monitoring applications

    Science.gov (United States)

    Beckmann, L.; Jacob, M.; Hoog Antink, C.; Cordes, A.; Pikkemaat, R.; Jungbecker, N.; Gries, T.; Leonhardt, S.

    2010-04-01

    A balanced body composition is necessary for a person's health and performance. Therefore, it is important to control the body composition continuously since complications and diseases due to dehydration often appear gradually. Based on these facts a miniaturized mobile Bioimpedance Spectroscopy device was developed that can be integrated into clothing and allows the continuous monitoring of a person's body water. The implemented system has been tested using different body models. The first measurements showed very precise and stable results. Besides the portable measurement system, textile electrodes are needed for continuous long term monitoring. Therefore, special textile electrodes were developed, tested and evaluated. The electrodes are structured in a specific way leading to a rougher surface. Such a surface improves the interface impedance and therefore optimizes the connection between electronic hardware and body. For comparison, five different structured electrodes were manufactured and tested on a special test setup that allows reproducible interface-impedance measurements using a dummy made of agar-agar to simulate the skin. It could be shown that the surface structure significantly influences the interface impedance in a positive way as compared to standard plane textile electrodes. In the future, a combination of the miniaturized BIS electronic and the structured textile electrodes could allow reproducible long term monitoring of a person's body composition.

  1. The Influence of Electrode and Channel Configurations on Flow Battery Performance

    Energy Technology Data Exchange (ETDEWEB)

    Darling, RM; Perry, ML

    2014-05-21

    Flow batteries with flow-through porous electrodes are compared to cells with porous electrodes adjacent to either parallel or interdigitated channels. Resistances and pressure drops are measured for different configurations to augment the electrochemical data. Cell tests are done with an electrolyte containing VO2+ and VO2+ in sulfuric acid that is circulated through both anode and cathode from a single reservoir. Performance is found to depend sensitively on the combination of electrode and flow field. Theoretical explanations for this dependence are provided. Scale-up of flow through and interdigitated designs to large active areas is also discussed. (C) 2014 The Electrochemical Society. All rights reserved.

  2. Influence of BaO in perovskite electrodes for the electrochemical reduction of NOx

    DEFF Research Database (Denmark)

    Simonsen, Vibe Louise Ernlund; Johnsen, M.M.; Kammer Hansen, Kent

    2007-01-01

    Using the point electrode method, the effect of BaO on electrochemical reduction of NO (x) was investigated using the perovskites La0.85Sr0.15MnO3 (LSM15) and La0.85Sr0.15CoO3 (LSCo15) as electrode materials. The experiments were carried out in the temperature range 400-600 degrees C in 1% NO and...... favored oxygen reduction compared to reduction of nitric oxide. The LSCO15 electrode containing BaO reacted to form a K2NiF4-structure and was not tested further....

  3. Alternating Pulse Current in Electrocoagulation for Wastewater Treatment to Prevent the Passivation or Al Electrode

    Institute of Scientific and Technical Information of China (English)

    MAO Xuhui; HONG Song; ZHU Hua; LIN Hui; WEI Lin; GAN Fuxing

    2008-01-01

    A novel current feed style, alternating pulse current, was proposed in electrocoagulation aiming at preventing the passivation of electrode materials. The open circuit potential (OCP) measurements after anodic and cathodic potentiodynamic polarization showed that cathodic polarization could activate Al electrode. The surface of Al electrode after alternating pulse current electrocoagulation was investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), and the results indicate that passivation of Al is not observed. Furthermore, the simulated wastewater treatment tests show that alternating pulse current electrocoagulation has a visible energy saving effect and is worthy of generalization.

  4. Performance of advanced chromium electrodes for the NASA Redox Energy Storage System

    Science.gov (United States)

    Gahn, R. F.; Charleston, J.; Ling, J. S.; Reid, M. A.

    1981-01-01

    Chromium electrodes were prepared for the NASA Redox Storage System with meet the performance requirements for solar-photovoltaic, wind-turbine and electric utility applications. Gold-lead catalyzed carbon felt electrodes up tp 930 sq cm were fabricated and tested in single cells and multicell stacks for hydrogen evolution, coulombic efficiency, catalyst stability and electrochemical activity. Factors which affect the overall performance of a particular electrode include the carbon felt lot, the cleaning treatment and the gold catalyzation method. Effects of the chromium solution chemistry and impurities on charge/discharge performance are also presented.

  5. Skin-electrode impedance measurement during ECG acquisition: method’s validation

    Science.gov (United States)

    Casal, Leonardo; La Mura, Guillermo

    2016-04-01

    Skm-electrode impedance measurement can provide valuable information prior. dunng and post electrocardiographic (ECG) or electroencephalographs (EEG) acquisitions. In this work we validate a method for skm-electrode impedance measurement using test circuits with known resistance and capacitor values, at different frequencies for injected excitation current. Finally the method is successfully used for impedance measurement during ECG acquisition on a subject usmg 125 Hz and 6 nA square wave excitation signal at instrumentation amplifier mput. The method can be used for many electrodes configuration.

  6. Improvement of electrochemical characteristics of natural graphite negative electrode coated with polyacrylic acid in pure propylene carbonate electrolyte

    Science.gov (United States)

    Ui, Koichi; Kikuchi, Shinei; Mikami, Fuminobu; Kadoma, Yoshihiro; Kumagai, Naoaki

    In order to improve the negative electrode characteristics of a graphite electrode in a propylene carbonate (PC)-containing electrolyte, we have prepared a graphite negative electrode coated with a water-soluble anionic polymer as a binder for composite graphite electrodes. The electrochemical characteristics of the coated graphite were evaluated by cyclic voltammetry and charge-discharge cycle tests. The coated graphite negative electrode showed a stable Li + ion intercalation/deintercalation reaction without the exfoliation of the graphene layers caused by the co-intercalation of the PC solvent in the LiClO 4/PC solution. The charge-discharge characteristic of the coated graphite negative electrode in a PC-containing electrolyte was almost the same as that in ethylene carbonate-based electrolyte.

  7. Improvement of LSM15-CGO10 electrodes for electrochemical removal of NOx by KNO3 and MnOx impregnation

    DEFF Research Database (Denmark)

    Traulsen, Marie Lund; Kammer Hansen, Kent

    2011-01-01

    in 1000 ppm NO, 10% O2 and 1000 ppm NO + 10% O2 in the temperature range 300-500 °C and the electrodes were investigated by scanning electron microscopy before and after testing. At 400-450 °C a NOx-storage process was observed on the KNO3-impregnated electrodes, this process appeared to be dependent...

  8. Determination of Three Dimensional Microstructure Parameters from a Solid Oxide Ni/YSZ Electrode after Electrolysis Operation

    DEFF Research Database (Denmark)

    Jørgensen, Peter Stanley; Bowen, Jacob R.

    2011-01-01

    The interface structure of a Ni/YSZ electrode tested for 1300 hours in steam electrolysis mode is analyzed. We break down the electrode interface structure measurements into total phase interfaces (e.g. total pore surface area), two-phase interfaces (e.g. Ni/YSZ interface area) and triple...

  9. Electrode-Skin contact impedance: In vivo measurements on an ovine model

    Science.gov (United States)

    Nguyen, D. T.; Kosobrodov, R.; Barry, M. A.; Chik, W.; Jin, C.; Oh, T. I.; Thiagalingam, A.; McEwan, A.

    2013-04-01

    The problem of electrical impedance between the skin and the electrode is an on-going challenge in bio-electronics. This is particularly true in the case of Electrical Impedance Tomography (EIT), which uses a large number of skin-contact electrodes and is very sensitive to noise. In the present article, contact impedance is measured and compared for a range of electrodes placed on the thorax of an ovine model. The study has been approved by the Westmead Hospital Animal Ethics Committee. The electrode models that were employed in the research are Ag/AgCl electrodes (E1), commonly used for ECG and EIT measurements in both humans and animal models, stainless steel crocodile clips (E2), typically used on animal models, and novel multi-point dry electrodes in two modifications: bronze plated (E3) and nickel plated (E4). Further, since the contact impedance is mostly attributed to the acellular outer layer of the skin, in our experiment, we attempted to study the effect of this layer by comparing the results when the skin is intact and when electrodes are introduced underneath the skin through small cuts. This boundary effect was assessed by comparison of measurements obtained during E2 skin surface contact, and sub-cutaneous contact (E5). Twelve gauge intradermal needles were also tested as an electrode (E6). The full impedance spectrum, from 500 Hz to 300 kHz, was recorded, analysed and compared. As expected, the contact impedance in the more invasive cases, i.e the electrodes under the skin, is significantly lower than in the non-invasive cases. At the frequency of 50 kHz which is commonly used in lung EIT acquisition, electrodes E3, E4 and E6 demonstrated contact impedance of less than 200 Ω, compared to more than 400 Ω measured for electrodes E1, E2 and E5. In conclusion, the novel multipoint electrodes proved to be best suited for EIT purposes, because they are non-invasive and have lower contact impedance than Ag/AgCl and crocodile clips, in both invasive and

  10. Frequency-domain analysis of intrinsic neuronal properties using high-resistant electrodes

    Directory of Open Access Journals (Sweden)

    Christian Rössert

    2009-08-01

    Full Text Available Intrinsic cellular properties of neurons in culture or slices are usually studied by the whole cell clamp method using low-resistant patch pipettes. These electrodes allow detailed analyses with standard electrophysiological methods such as current- or voltage-clamp. However, in these preparations large parts of the network and dendritic structures may be removed, thus preventing an adequate study of synaptic signal processing. Therefore, intact in vivo preparations or isolated in vitro whole brains have been used in which intracellular recordings are usually made with sharp, high-resistant electrodes to optimize the impalement of neurons. The general non-linear resistance properties of these electrodes, however, severely limit accurate quantitative studies of membrane dynamics especially needed for precise modelling. Therefore, we have developed a frequency-domain analysis of membrane properties that uses a Piece-wise Non-linear Electrode Compensation (PNEC method. The technique was tested in second-order vestibular neurons and abducens motoneurons of isolated frog whole brain preparations using sharp potassium chloride- or potassium acetate-filled electrodes. All recordings were performed without online electrode compensation. The properties of each electrode were determined separately after the neuronal recordings and were used in the frequency-domain analysis of the combined measurement of electrode and cell. This allowed detailed analysis of membrane properties in the frequency-domain with high-resistant electrodes and provided quantitative data that can be further used to model channel kinetics. Thus, sharp electrodes can be used for the characterization of intrinsic properties and synaptic inputs of neurons in intact brains.

  11. Carbon-based Composite Electrodes: Preparation, Characterization and Application in Electroanalysis

    Directory of Open Access Journals (Sweden)

    Joop Schoonman

    2007-11-01

    Full Text Available Electrodes based on carbon, i.e., expanded graphite (20%, wt.-epoxy composite(20EG-Epoxy and expanded graphite (20%, wt.-polystyrene composite (20EG-PS havebeen prepared, characterized using scanning electron microscopy (SEM and cyclicvoltammetry (CV, and tested as anodic sensors. The electrodes exhibited good mechanicalresistance and low electrical resistances. Scan rate dependent cyclic voltammetry responsesat 20EG-Epoxy and 20EG-PS composite electrodes, which were exemplified for thiourea(TU, a toxic sulphur organic compound selected as testing target analyte in 0.1 M Na2SO4 supporting electrolyte, were investigated. The obtained voltammetric data were inaccordance with those for a random array of microelectrodes. The voltammetric andchronoamperometric detection results of TU in tap water samples, without a supplementaryaddition of supporting electrolyte, at 20EG-Epoxy electrode proved its use for directanalysis of environmental samples.

  12. Domestic and Industrial Water Disinfection Using Boron-Doped Diamond Electrodes

    Science.gov (United States)

    Rychen, Philippe; Provent, Christophe; Pupunat, Laurent; Hermant, Nicolas

    This chapter first describes main properties and manufacturing process (production using HF-CVD, quality-control measurements, etc.) of diamond electrodes and more specifically boron-doped diamond (BDD) electrodes. Their exceptional properties make such electrodes particularly suited for many disinfection applications as thanks to their wide working potential window and their high anodic potential, they allow generating a mixture of powerful oxidizing species mainly based on active oxygen and peroxides. Such mixture of disinfecting agents is far more efficient than conventional chemical or physical known techniques. Their efficiency was tested against numerous microorganisms and then proved to be greater than conventional methods. All bacteria and viruses tested up to date were inactivated 3-5 times faster with a treatment based on with BDD electrodes and the DiaCellⓇ technology than with other techniques. Several applications, either industrial or private (wellness and home use), are discussed with a focus on the dedicated products and the main technology advantages.

  13. Bathymetry of Clear Creek Reservoir, Chaffee County, Colorado, 2016

    Science.gov (United States)

    Kohn, Michael S.; Kinzel, Paul J.; Mohrmann, Jacob S.

    2017-03-06

    To better characterize the water supply capacity of Clear Creek Reservoir, Chaffee County, Colorado, the U.S. Geological Survey, in cooperation with the Pueblo Board of Water Works and Colorado Mountain College, carried out a bathymetry survey of Clear Creek Reservoir. A bathymetry map of the reservoir is presented here with the elevation-surface area and the elevation-volume relations. The bathymetry survey was carried out June 6–9, 2016, using a man-operated boat-mounted, multibeam echo sounder integrated with a Global Positioning System and a terrestrial survey using real-time kinematic Global Navigation Satellite Systems. The two collected datasets were merged and imported into geographic information system software. The equipment and methods used in this study allowed water-resource managers to maintain typical reservoir operations, eliminating the need to empty the reservoir to carry out the survey.

  14. Clear sky atmosphere at cm-wavelengths from climatology data

    CERN Document Server

    Lew, Bartosz

    2015-01-01

    We utilise ground-based, balloon-born and satellite climatology data to reconstruct site and season-dependent vertical profiles of precipitable water vapour (PWV). We use these profiles to numerically solve radiative transfer through the atmosphere, and derive atmospheric brightness temperature ($T_{\\rm atm}$) and optical depth ($\\tau$) at the centimetre wavelengths. We validate the reconstruction by comparing the model column PWV, with photometric measurements of PWV, performed in the clear sky conditions towards the Sun. Based on the measurements, we devise a selection criteria to filter the climatology data to match the PWV levels to the expectations of the clear sky conditions. We apply the reconstruction to the location of the Polish 32-metre radio telescope, and characterise $T_{\\rm atm}$ and $\\tau$ year-round, at selected frequencies. We also derive the zenith distance dependence for these parameters, and discuss shortcomings of using planar, single-layer, and optically thin atmospheric model approxima...

  15. Clear cell sarcoma of the kidney: A case report

    Directory of Open Access Journals (Sweden)

    Dipanwita Nag

    2014-01-01

    Full Text Available Clear cell sarcoma of the kidney is a rare malignant neoplasm of childhood, known for its aggressiveness, its tendency for recurrence, and to metastasize to bone. We report the observation of 8-month-old child presenting with a large abdominal mass. Clinically, it was diagnosed as Wilm′s tumor, and left nephrectomy was done. Grossly, 10 cm × 8 cm × 3.5 cm globular, white, encapsulated, smooth mass uniformly involving the whole kidney was noted. Histologically, the tumor was diagnosed as clear cell sarcoma with renal vein showing presence of tumor embolus in lumen. The tumor was given stage-II (NWTS-5 protocol. Immunohistochemistry showed vimentin positive and cytokeratin negative tumor cells. The child is currently undergoing chemotherapy and has not yet shown any sign of bony metastasis.

  16. Effects of Mixing on Hopper Sedimentation in Clearing Mixtures

    DEFF Research Database (Denmark)

    Hjelmager Jensen, Jacob; Saremi, Sina

    2015-01-01

    and settling in high-concentration mixtures were examined theoretically. Analytical solutions for clearance of excess concentrations were derived for the limiting cases of (1) still-water clearance and (2) clearance when the amount of turbulence is abundant. When examining these analytical solutions......Hopper sedimentation is the result of precipitation of typically fine sediment from a homogenous, high-concentration mixture, which is not completely deficient of turbulence. If hopper sedimentation or loading is accomplished through a single-inflow system, or if the irregularity of the inflow...... concentrations is pronounced or simply terminated, then the hopper mixture will clear. Whereas turbulent mixing is redundant, when the mixture is homogeneous, it may take an active role when the mixture is clearing. The role of turbulence on hopper sedimentation has been the focus of several studies...

  17. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Science.gov (United States)

    Bugalho, R.; Carriço, B.; Ferreira, C. S.; Frade, M.; Ferreira, M.; Moura, R.; Ortigão, C.; Pinheiro, J. F.; Rodrigues, P.; Rolo, I.; Silva, J. C.; Trindade, A.; Varela, J.

    2009-10-01

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Português de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 × 2 × 20 mm3 LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean CDOI-1 is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  18. ClearFuels-Rentech Integrated Biorefinery Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, Joshua [Project Director

    2014-02-26

    The project Final Report describes the validation of the performance of the integration of two technologies that were proven individually on a pilot scale and were demonstrated as a pilot scale integrated biorefinery. The integrated technologies were a larger scale ClearFuels’ (CF) advanced flexible biomass to syngas thermochemical high efficiency hydrothermal reformer (HEHTR) technology with Rentech’s (RTK) existing synthetic gas to liquids (GTL) technology.

  19. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Energy Technology Data Exchange (ETDEWEB)

    Bugalho, R; Carrico, B; Ferreira, C S; Frade, M; Ferreira, M; Moura, R; Ortigao, C; Pinheiro, J F; Rodrigues, P; Rolo, I; Silva, J C; Trindade, A; Varela, J [Laboratorio de Instrumentacao e Fisica Experimental de Particulas (LIP), Av. Elias Garcia 14-1, 1000-149 Lisboa (Portugal)], E-mail: frade@lip.pt

    2009-10-15

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Portugues de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 x 2 x 20 mm{sup 3} LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean C{sub DOI}{sup -1} is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  20. Impulse space charge and dielectric characteristics of an Al2O3 nanoparticle suspension in propylene carbonate using various electrode materials

    Directory of Open Access Journals (Sweden)

    Qing Yang

    2016-09-01

    Full Text Available We tested the impulse breakdown voltage of Al2O3 “nano-modified” propylene carbonate between different electrode materials. At any given concentration, the breakdown voltage was highest with stainless steel electrodes, followed by copper, and then aluminum. The space charge and electric field distributions were measured too. Results show that less space charge was injected by the electrodes, and the electric field was less distorted, than in pure propylene carbonate. However, the hoped-for reduction of the influence of the electrodes did not take place. Substantial differences in the space charge density and electric field distortion remained between the different electrode materials.

  1. Development of a Micro-Fiber Nickel Electrode for Nickel-Hydrogen Cell

    Science.gov (United States)

    Britton, Doris L.

    1996-01-01

    The development of a high specific energy battery is one of the objectives of the lightweight nickel-hydrogen (NiH2) program at the NASA Lewis Research Center. The approach has been to improve the nickel electrode by continuing combined in-house and contract efforts to develop a more efficient and lighter weight electrode for the nickel-hydrogen fuel cell. Small fiber diameter nickel plaques are used as conductive supports for the nickel hydroxide active material. These plaques are commercial products and have an advantage of increased surface area available for the deposition of active materials. Initial tests include activation and capacity measurements at different discharge levels followed by half-cell cycle testing at 80 percent depth-of-discharge in a low Earth orbit regime. The electrodes that pass the initial tests are life cycle tested in a boiler plate nickel-hydrogen cell before flightweight designs are built and tested.

  2. Mutagens in urine of carbon electrode workers

    Energy Technology Data Exchange (ETDEWEB)

    Pasquini, R.; Monarca, S.; Sforzolini, G.S.; Conti, R.; Fagioli, F.

    1982-01-01

    Following previous work carried out in an Italian factory producing carbon electrodes and evaluating the occupational mutagenic-carcinogenic hazards, the authors studied the presence of mutagen metabolites in the urine of workers in the same factory who were exposed to petroleum coke and pitch and in the urine of a control group of unexposed workers. The urine samples were concentrated by absorption on XAD-2 columns and were tested using the Salmonella/microsome assay (strain TA98, TA100, TA1535, TA1538) with and without the addition of beta-glucuronidase and metabolizing system. The collection of urine samples was carried out twice, with an interval of 2 months; 'before working time', 'after working time', and also during Sunday. The results showed that urine samples collected 'before' occupational exposure (upon waking) or on Sunday revealed no mutagenic activity in either worker groups and that the urine samples collected after or during occupational exposure revealed high mutagenic activity in the exposed workers, with a statistically significant difference between the mean of the revertants/plate values for exposed and unexposed workers. On the basis of the previous and the present research, the authors suggest that application of the Salmonella/microsome test to work environments could offer useful and suitable tool for evaluating the health hazards due to mutagenic/carcinogenic substances from occupational exposure.

  3. Dry Electrodes Facilitate Remote Health Monitoring

    Science.gov (United States)

    2013-01-01

    Johnson Space Center collaborated with Blacksburg, Virginia-based NanoSonic Inc. through the SBIR program to devise a sensor to replace the traditional electrodes used for an electrocardiogram in space. In 2011, NanoSonic started marketing the dry electrodes as well as an EKGear Sensor Shirt, which is being considered for use in hospital garments, athletic apparel, and dive suits.

  4. Lithium metal oxide electrodes for lithium batteries

    Science.gov (United States)

    Thackeray, Michael M.; Kim, Jeom-Soo; Johnson, Christopher S.

    2008-01-01

    An uncycled electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula Li.sub.(2+2x)/(2+x)M'.sub.2x/(2+x)M.sub.(2-2x)/(2+x)O.sub.2-.delta., in which 0.ltoreq.xbatteries containing the electrodes.

  5. New electrosurgical ball electrode with nonstick properties

    Science.gov (United States)

    Rondinone, Joseph; Brassell, James; Miller, Scott A., III; Thorne, Jonathan O.; Rondinone, David M.; Safabash, Jason; Vega, Felix

    1998-04-01

    A new electrosurgical ball electrode (SilverBulletTM) has been developed for applying radiofrequency (RF) energy to fuse biological and other materials to tissue surfaces. Specifically, the electrode was developed for use in conjunction with the Fusion Medical Technologies, Inc. gelatin patch (RapiSealTM) for use in pulmonary surgery to seal air leaks, and in solid abdominal organ surgeries to provide hemostatic tamponade. The new electrode allows for the application of RF energy in contact mode without the problems of the electrode sticking to the gelatin patch or the underlying tissue. Designed for use with commercially available electrosurgical handpieces, the electrode consists of a stainless steel connector that fits into the hand- piece, and an electrode assembly made from silver that includes a shank region, and a tip extension extending distally from the shank region. The distal tip of the tip extension is rounded and has a length of about 10 mm. The uniqueness of this electrode is the shank region which has a cross sectional area that is larger than the tip extension. The shank region acts as a heat sink to draw away heat from the tip extension while the tip extension itself remains sufficiently small to access desired target sites and display the desired energy transfer properties. In addition to the physical design, the use of silver as the core element provides a material with high electrical and thermal conductivities. The bulk of the electrode is appropriately insulated.

  6. Electrode kinetics and double layer structure

    NARCIS (Netherlands)

    Timmer, B.; Sluyters-Rehbach, M.; Sluyters, J.H.

    1969-01-01

    Several electrochemical methods have been developed in recent years for the study of the kinetic parameters of electrode reactions. These methods have been used for obtaining an abundance of experimental data for the standard heterogeneous rate constant, ksh, of electrode reactions, mostly limited t

  7. Confinement of reaction components at electrode surface

    Energy Technology Data Exchange (ETDEWEB)

    Luca, Oana R.; Weitekamp, Raymond; Grubbs, Robert H.; Atwater, Harry A.; Mitrovic, Slobodan

    2017-03-14

    A CO.sub.2 reduction electrode includes an active layer on an electrode base. The active layer includes a polymer that includes one or more reaction components selected from a group consisting of a CO.sub.2 reduction catalyst and an activator that bonds CO.sub.2 so as to form a CO.sub.2 reduction intermediate.

  8. Gas tungsten arc welder with electrode grinder

    Science.gov (United States)

    Christiansen, David W.; Brown, William F.

    1984-01-01

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  9. 3-Dimensional Calculations on Smelting Electrodes

    Directory of Open Access Journals (Sweden)

    Reidar Innvær

    1987-04-01

    Full Text Available Søderberg selfbaking electrodes are used to conduct electric current into the electric reduction furnace. Two-dimensional computer models for the computation of temperatures, electric currents and thermal stresses have been used for a long time in the R&D effort to improve the construction and operation of the electrode.

  10. electrode of an arbitrary shape

    Directory of Open Access Journals (Sweden)

    P. A. Krutitskii

    1999-01-01

    Full Text Available A problem on electric current in a semiconductor film from an electrode of an arbitrary shape is studied in the presence of a magnetic field. This situation describes the Hall effect, which indicates the deflection of electric, current from electric field in a semiconductor. From mathematical standpoint we consider the skew derivative problem for harmonic functions in the exterior of an open arc in a plane. By means of potential theory the problem is reduced to the Cauchy singular integral equation and next to the Fredholm equation of the 2nd kind which is uniquely solvable. The solution of the integral equation can be computed by standard codes by discretization and inversion of the matrix. The uniqueness and existence theorems are formulated.

  11. Surface characterization of platinum electrodes.

    Science.gov (United States)

    Solla-Gullón, José; Rodríguez, Paramaconi; Herrero, Enrique; Aldaz, Antonio; Feliu, Juan M

    2008-03-14

    The quantitative analysis of the different surface sites on platinum samples is attempted from pure voltammetric data. This analysis requires independent knowledge of the fraction of two-dimensional (111) and (100) domains. Specific site-probe reactions are employed to achieve this goal. Irreversibly-adsorbed bismuth and tellurium have been revealed to be sensitive to the presence of (111) terrace domains of different width whereas almost all sites involved in (100) ordered domains have been characterized through germanium adatoms. The experimental protocol follows that used with well-defined single-crystal electrodes and, therefore, requires careful control of the surface cleanliness. Platinum basal planes and their vicinal stepped surfaces have been employed to obtain calibration plots between the charge density measured under the adatom redox peak, specific for the type of surface site, and the corresponding terrace size. The evaluation of the (100) bidimensional domains can also be achieved using the voltammetric profiles, once the fraction of (111) ordered domains present in the polyoriented platinum has been determined and their featureless contribution has been subtracted from the whole voltammetric response. Using that curve, it is possible to perform a deconvolution of the adsorption states of the polycrystalline sample different from those related to (111) domains. The fraction of (100)-related states in the deconvoluted voltammogram can then be compared to that expected from the independent estimation coming from the charge involved in the redox process undergone by the irreversibly-adsorbed germanium and thus check the result of the deconvolution. The information about the surface-site distribution can also be applied to analyze the voltammetric profile of nanocrystalline platinum electrodes.

  12. Multi-walled carbon nanotubes (MWCNT) as compliant electrodes for dielectric elastomer actuators

    Science.gov (United States)

    Chua, Soo-Lim; Neo, Xin-Hui; Lau, Gih-Keong

    2011-04-01

    evaporation from the MWCNT-COOH electrode. The actuators with MWCNT-COOHs electrodes, prepared from the solvent dispersion, produce a low actuation strain even though these electrodes have good conductivity and these solvents do not degrade the physical properties of the dielectric layer. This finding on the solvent effect has yet been clearly understood.

  13. Ni-Based Solid Oxide Cell Electrodes

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Holtappels, Peter

    2013-01-01

    This paper is a critical review of the literature on nickel-based electrodes for application in solid oxide cells at temperature from 500 to 1000 _C. The applications may be fuel cells or electrolyser cells. The reviewed literature is that of experimental results on both model electrodes...... and practical composite cermet electrodes. A substantially longer three-phase boundary (TPB) can be obtained per unit area of cell in such a composite of nickel and electrolyte material, provided that two interwoven solid networks of the two solid and one gaseous phases are obtained to provide a three...... - dimensional TPB throughout the electrode volume. Variables that are used for controlling the properties of Ni-cermet electrodes are: (1) Ni/YSZ volume ratio, and (2) porosity and particle size distribution, which mainly affected by raw materials morphology, application methods and production parameters...

  14. Accuracy of the ABC/2 score for intracerebral hemorrhage: Systematic review and analysis of MISTIE, CLEAR-IVH, CLEAR III

    Science.gov (United States)

    Webb, Alastair JS; Ullman, Natalie L; Morgan, Tim C; Muschelli, John; Kornbluth, Joshua; Awad, Issam A; Mayo, Stephen; Rosenblum, Michael; Ziai, Wendy; Zuccarrello, Mario; Aldrich, Francois; John, Sayona; Harnof, Sagi; Lopez, George; Broaddus, William C; Wijman, Christine; Vespa, Paul; Bullock, Ross; Haines, Stephen J; Cruz-Flores, Salvador; Tuhrim, Stan; Hill, Michael D; Narayan, Raj; Hanley, Daniel F

    2015-01-01

    Background and Purpose The ABC/2 score estimates intracerebral hemorrhage (ICH) volume, yet validations have been limited by small samples and inappropriate outcome measures. We determined accuracy of the ABC/2 score calculated at a specialized Reading Center (RC-ABC) or local site (site-ABC) versus the reference-standard CT-based planimetry (CTP). Methods In MISTIE-II, CLEAR-IVH and CLEAR-III trials, ICH volume was prospectively calculated by CTP, RC-ABC and site-ABC. Agreement between CTP and ABC/2 was defined as an absolute difference up to 5ml and relative difference within 20%. Determinants of ABC/2 accuracy were assessed by logistic regression. Results In 4369 scans from 507 patients, CTP was more strongly correlated with RC-ABC (r2=0.93) than site-ABC (r2=0.87). Although RC-ABC overestimated CTP-based volume on average (RC-ABC=15.2cm3, CTP=12.7cm3), agreement was reasonable when categorised into mild, moderate and severe ICH (kappa 0.75, p<0.001). This was consistent with overestimation of ICH volume in 6/8 previous studies. Agreement with CTP was greater for RC-ABC (84% within 5ml; 48% of scans within 20%) than for site-ABC (81% within 5ml; 41% within 20%). RC-ABC had moderate accuracy for detecting ≥ 5ml change in CTP volume between consecutive scans (sensitivity 0.76, specificity 0.86) and was more accurate with smaller ICH, thalamic haemorrhage and homogeneous clots. Conclusions ABC/2 scores at local or central sites are sufficiently accurate to categorise ICH volume and assess eligibility for the CLEAR III and MISTIE III studies, and moderately accurate for change in ICH volume. However, accuracy decreases with large, irregular or lobar clots. Clinical Trial Registration MISTIE-II NCT00224770; CLEAR-III NCT00784134; www.clinicaltrials.gov PMID:26243227

  15. The underlying electrode causes the reported 'electro-catalysis' observed at C{sub 60}-modified glassy carbon electrodes in the case of N-(4-hydroxyphenyl)ethanamide and salbutamol

    Energy Technology Data Exchange (ETDEWEB)

    Griese, Sebastian; Kampouris, Dimitrios K.; Kadara, Rashid O.; Banks, Craig E. [Faculty of Science and Engineering, School of Biology, Chemistry and Health Science, Division of Chemistry and Materials, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, Lancs (United Kingdom)

    2008-08-20

    The reported 'electro-catalysis' of C{sub 60}-film-modified electrodes for the electrochemical oxidation of N-(4-hydroxyphenyl)ethanamide and salbutamol has been explored at boron-doped diamond and glassy carbon electrodes. Using both C{sub 60}-film-modified boron-doped diamond and glassy carbon as underlying electrode substrates no electro-catalytic response is observed using the target analytes but rather the C{sub 60} serves to block the electrode surface. A common experimental protocol used by researchers in this field is to electrochemically pre-treat the C{sub 60}-film-modified electrode. The response of employing this electrochemical pre-treatment at both bare glassy carbon and boron-doped diamond electrodes using the target analytes reveals that no effect on the electrochemical responses obtained at the boron-doped diamond electrode whereas a slight but significant effect occurs on glassy carbon which is attributed to the likely introduction of surface oxygenated species. Consequently the previously reported 'electro-catalysis' using C{sub 60}-film-modified electrode is not due to C{sub 60} itself being catalytic, but rather that substrate activation through electrode pre-treatment is responsible for the observed 'electro-catalysis' likely through the introduction of surface oxygenated species. This work clearly shows that substrate activation is an important parameter which researchers studying C{sub 60}-film-modified electrodes, especially in electro-analysis needs to be considered. (author)

  16. A pilot study comparing opaque, weighted bottles with conventional, clear bottles for infant feeding.

    Science.gov (United States)

    Ventura, Alison K; Pollack Golen, Rebecca

    2015-02-01

    It is hypothesized that the visual and weight cues afforded by bottle-feeding may lead mothers to overfeed in response to the amount of liquid in the bottle. The aim of the present pilot study was to test this hypothesis by comparing mothers' sensitivity and responsiveness to infant cues and infants' intakes when mothers use opaque, weighted bottles (that remove visual and weight cues) compared to conventional, clear bottles to feed their infants. We also tested the hypothesis that mothers' pressuring feeding style would moderate the effect of bottle type. Formula-feeding dyads (N = 25) visited our laboratory on two separate days. Mothers fed their infants from a clear bottle one day and an opaque, weighted bottle on the other; bottle-order was counterbalanced across the two days. Infant intake was assessed by weighing each bottle before and after the feeding. Maternal sensitivity and responsiveness to infant cues was objectively assessed using the Nursing Child Assessment Feeding Scale. Mothers were significantly more responsive to infant cues when they used opaque compared to clear bottles (p = .04). There was also a trend for infants to consume significantly less formula when fed from opaque compared to clear bottles (p = .08). Mothers' pressuring feeding style moderated the effect of bottle type on maternal responsiveness to infant cues (p = .02) and infant intake (p = .03). Specifically, mothers who reported higher levels of pressuring feeding were significantly more responsive to their infants' cues (p = .02) and fed their infants significantly less formula when using opaque versus clear bottles (p = .01); no differences were seen for mothers who reported lower levels of pressuring feeding. This study highlights a simple, yet effective intervention for improving the bottle-feeding practices of mothers who have pressuring feeding styles.

  17. Textile electrode characterization: dependencies in the skin-clothing-electrode interface

    Science.gov (United States)

    Macías, R.; Fernández, M.; Bragós, R.

    2013-04-01

    Given the advances in the technology known as smart textiles, the use of textile electrodes is more and more common. However this kind of electrodes presents some differences regarding the standard ones as the Ag-AgCl electrodes. Therefore to characterize them as best as possible is required. In order to make the characterization reproducible and repetitive, a skin dummy made of agar-agar and a standardized measurement set-up is used in this article. Thus, some dependencies in the skin-electrode interface are described. These dependencies are related to the surface of the textile electrode, the conductive material and the applied pressure. Furthermore, the dependencies on clothing in the skin-textile electrode interface are also analyzed. Thus, based on some parameters such as textile material, width and number of layers, the behavior of the interface made up by the skin, the textile electrode and clothing is depicted.

  18. Optimization of return electrodes in neurostimulating arrays

    Science.gov (United States)

    Flores, Thomas; Goetz, Georges; Lei, Xin; Palanker, Daniel

    2016-06-01

    Objective. High resolution visual prostheses require dense stimulating arrays with localized inputs of individual electrodes. We study the electric field produced by multielectrode arrays in electrolyte to determine an optimal configuration of return electrodes and activation sequence. Approach. To determine the boundary conditions for computation of the electric field in electrolyte, we assessed current dynamics using an equivalent circuit of a multielectrode array with interleaved return electrodes. The electric field modeled with two different boundary conditions derived from the equivalent circuit was then compared to measurements of electric potential in electrolyte. To assess the effect of return electrode configuration on retinal stimulation, we transformed the computed electric fields into retinal response using a model of neural network-mediated stimulation. Main results. Electric currents at the capacitive electrode-electrolyte interface redistribute over time, so that boundary conditions transition from equipotential surfaces at the beginning of the pulse to uniform current density in steady state. Experimental measurements confirmed that, in steady state, the boundary condition corresponds to a uniform current density on electrode surfaces. Arrays with local return electrodes exhibit improved field confinement and can elicit stronger network-mediated retinal response compared to those with a common remote return. Connecting local return electrodes enhances the field penetration depth and allows reducing the return electrode area. Sequential activation of the pixels in large monopolar arrays reduces electrical cross-talk and improves the contrast in pattern stimulation. Significance. Accurate modeling of multielectrode arrays helps optimize the electrode configuration to maximize the spatial resolution, contrast and dynamic range of retinal prostheses.

  19. Cyclic Voltammetric Responses of Nitrate Reductase on Chemical Modified Electrodes

    Institute of Scientific and Technical Information of China (English)

    YaRuSONG; HuiBoSHAO; 等

    2002-01-01

    Electrochemistry of nitrate reductases (NR) incorporated into 2-aminoethanethiol self-assembled on the gold electrode and polyacrylamide cast on the pyrolytic graphite electrode was examined. NR on chemical modified electrode showed electrochemical cyclic voltammetric responses in phosphate buffers.

  20. Identifying fly puparia by clearing technique: application to forensic entomology.

    Science.gov (United States)

    Sukontason, Kabkaew L; Ngern-Klun, Radchadawan; Sripakdee, Duanghatai; Sukontason, Kom

    2007-10-01

    In forensic investigations, immature stages of the fly (egg, larva, or puparia) can be used as entomological evidence at death scenes, not only to estimate the postmortem interval (PMI), analyze toxic substances, and to determine the manner of death but also to indicate the movement of a corpse in homicide cases. Of these immature stages, puparia represent the longest developmental time, which makes them of useful. However, in order for forensic entomologists to use puparia effectively, it is crucial that they are able to accurately identify the species of fly found in a corpse. Typically, these puparia are similar in general appearance, being coarctate and light brown to dark brown in color, which makes identification difficult. In this study, we report on the clearing technique used to pale the integument of fly puparia, thereby allowing observation of the anterior end (second to fourth segments) and the profile of the posterior spiracle, which are important clues for identification. We used puparia of the blowfly, Chrysomya megacephala (F.), as the model species in this experiment. With placement in a 20% potassium hydroxide solution daily and mounting on a clearing medium (Permount(R), New Jersey), the profile of the posterior spiracle could be clearly examined under a light microscope beginning on the fifth day after pupation, and the number of papillae in the anterior spiracle could be counted easily starting from the ninth day. Comparison of morphological features of C. megacephala puparia with those of other blowflies (Chrysomya nigripes [Aubertin], Chrysomya rufifacies [Macquart], Chrysomya villeneuvi [Patton], Lucilia cuprina [Wiedemann], and Hemipyrellia ligurriens [Wiedemann]) and a housefly (Musca domestica L.) revealed that the anterior ends and the profiles of the posterior spiracles had markedly distinguishing characteristics. Morphometric analysis of the length and width of puparia, along with the length of the gaps between the posterior spiracles

  1. The definition of IVM is clear-variations need defining.

    Science.gov (United States)

    De Vos, Michel; Smitz, Johan; Thompson, Jeremy G; Gilchrist, Robert B

    2016-11-01

    Oocyte in vitro maturation (IVM) is currently defined as the maturation in vitro of immature cumulus-oocyte complexes collected from antral follicles. This is the original definition as first described by Pincus and Enzmann and then by Edwards many decades ago, and this clear and unambiguous definition has served us well ever since. In an attempt to clarify apparent differences among clinicians, the following revised definition of IVM was recently proposed: 'The retrieval of oocytes from small and intermediate sized follicles in an ovary before the largest follicle has surpassed 13 mm in mean diameter'. As such, this proposed definition should encompass the use of hCG triggering. To change the clear and long-serving definition of IVM to fit varying clinical practices requires a compelling justification based on solid scientific and clinical grounds. We are of the opinion that the proposed revised definition of IVM is counterintuitive as it includes protocols that are intended to mature oocytes in vivo The proposed definitions are cumbersome and indeed further complicate the situation. It is not scientifically rational to base the definition on follicular size, and the definition ignores the vast corporate knowledge acquired from the many decades and >6000 publications in animal research that universally practices IVM as per the existing definition. Furthermore, such a definition can lead to false results in interpreting the follow-up of children conceived using IVM. Hence, we see no rationale to change the existing definition of IVM. However, we agree that variations on IVM require alternative nomenclature-these definitions need to be intuitive and need to clearly distinguish themselves from the existing long-standing definition of IVM. This would help to clarify the recent confusion within the clinical ART community as to what is and what is not, IVM.

  2. Direct determination of triamterene by potentiometry using a coated wire selective electrode.

    Science.gov (United States)

    Arvand, M; Mousavi, M F; Zanjanchi, M A; Shamsipur, M

    2003-12-04

    A coated wire triamterene-selective electrode based on the incorporation of a triamterene-tetraphenylborate ion-pair in a poly(vinylchloride) coating membrane was constructed. The influence of membrane composition, temperature, pH of the test solution, and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian response over a triamterene concentration range from 1.0 x 10(-6) to 3.5 x 10(-2) M, at 25 degrees C, and was found to be very selective, precise, and usable within the pH range 4.5-7.5. The standard electrode potentials, E degrees, were determined at 15, 20, 25, 30, 35, 40 and 45 degrees C and used to calculate the isothermal temperature coefficient (dE degrees /dt) of the electrode. Temperatures higher than 45 degrees C seriously affected the electrode performance. The electrode was successfully applied to the potentiometric determination of triamterene hydrochloride both in pure solutions and in pharmaceutical preparations.

  3. On-Chip Supercapacitor Electrode Based On Polypyrrole Deposited Into Nanoporous Au Scaffold

    Science.gov (United States)

    Lu, P.; Ohlckers, P.; Chen, X. Y.

    2016-11-01

    On-chip supercapacitors hold the potential promise for serving as the energy storage units in integrated circuit system, due to their much higher energy density in comparison with conventional dielectric capacitors, high power density and long-term cycling stability. In this study, nanoporous Au (NP-Au) film on-chip was employed as the electrode scaffold to help increase the electrolyte-accessible area for active material. Pseudo-capacitive polypyrrole (PPY) with high theoretical capacitance was deposited into the NP-Au scaffold, to construct the tailored NP-Au/PPY hybrid on-chip electrode with improved areal capacitance. Half cell test in three- electrode system revealed the improved capacitor performance of nanoporous Au supported PPY electrode, compared to the densely packed PPY nanowire film electrode on planer Au substrate (Au/PPY). The areal capacitance of 37 mF/cm2∼10 mV/s, 32 mF/cm2∼50 mV/s, 28 mF/cm2∼100 mV/s, 16 mF/cm2∼500 mV/s, were offered by NP-Au/PPY. Also, the cycling performance was enhanced via using NP-Au scaffold. The developed NP-Au/PPY on-chip electrode demonstrated herein paves a feasible pathway to employ dealloying derived porous metal as the scaffold for improving both the energy density and cycling performance for supercapacitor electrodes.

  4. Electroanalytical sensing of chromium(III) and (VI) utilising gold screen printed macro electrodes.

    Science.gov (United States)

    Metters, Jonathan P; Kadara, Rashid O; Banks, Craig E

    2012-02-21

    We report the fabrication of gold screen printed macro electrodes which are electrochemically characterised and contrasted to polycrystalline gold macroelectrodes with their potential analytical application towards the sensing of chromium(III) and (VI) critically explored. It is found that while these gold screen printed macro electrodes have electrode kinetics typically one order of magnitude lower than polycrystalline gold macroelectrodes as is measured via a standard redox probe, in terms of analytical sensing, these gold screen printed macro electrodes mimic polycrystalline gold in terms of their analytical performance towards the sensing of chromium(III) and (VI), whilst boasting additional advantages over the macro electrode due to their disposable one-shot nature and the ease of mass production. An additional advantage of these gold screen printed macro electrodes compared to polycrystalline gold is the alleviation of the requirement to potential cycle the latter to form the required gold oxide which aids in the simplification of the analytical protocol. We demonstrate that gold screen printed macro electrodes allow the low micro-molar sensing of chromium(VI) in aqueous solutions over the range 10 to 1600 μM with a limit of detection (3σ) of 4.4 μM. The feasibility of the analytical protocol is also tested through chromium(VI) detection in environmental samples.

  5. Effect of different electrodes on the transport properties of ZnO nanofibers under humid environment

    Directory of Open Access Journals (Sweden)

    Z. Imran

    2015-11-01

    Full Text Available Relative humidity (RH sensing properties of zinc oxide nanofibers (ZNF, synthesized using electrospinning technique, were studied by impedance spectroscopy. RH sensors were fabricated with two different electrodes (Au and Ni using lithography on top of the nanofibers deposited on Si/SiO2 substrate. Compare with the Ni electrode sensor, Au electrode sensor exhibits larger sensitivity and quicker response/recovery. Capacitance, electrical conductivity and electrical modulus were studied at 40%-90% RH as a function of the frequency of the applied AC signal in the frequency range of 10−2-106 Hz. The corresponding response and recovery times are 3s and 5s for Au, and 6s and 10s for Ni electrode sensor, respectively. The sensors exhibited a reversible response with small hysteresis of less than 4% and 12% for Au and Ni electrodes respectively. Stability of the sensor device with Au electrode was confirmed by testing the device for 13 days. The excellent sensing characteristics and comparison of sensors with different electrode materials may offer an effective route for designing and optimizing RH sensors.

  6. The differing behavior of electrosurgical devices made of various electrode materials operating under plasma conditions

    Science.gov (United States)

    Stalder, K. R.; Ryan, T. P.; Gaspredes, J.; Woloszko, J.

    2015-03-01

    Coblation® is an electrosurgical technology which employs electrically-excited electrodes in the presence of saline solution to produce a localized and ionized plasma that can cut, ablate, and otherwise treat tissues for many different surgical needs. To improve our understanding of how Coblation plasmas develop from devices made from different electrode materials we describe several experiments designed to elucidate material effects. Initial experiments studied simple, noncommercial cylindrical electrode test devices operating in buffered isotonic saline without applied suction. The applied RF voltage, approximately 300 V RMS, was sufficient to form glow discharges around the active electrodes. The devices exhibited significantly different operating characteristics, which we ascribe to the differing oxidation tendencies and other physical properties of the electrode materials. Parameters measured include RMS voltage and current, instantaneous voltage and current, temporally-resolved light emission and optical emission spectra, and electrode mass-loss measurements. We correlate these measured properties with some of the bulk characteristics of the electrode materials such as work functions, standard reduction potentials and sputter yields.

  7. A new method for measuring the Faradic resistance of a single electrode-electrolyte interface.

    Science.gov (United States)

    Mayer, S; Geddes, L A; Bourland, J D; Ogborn, L

    1992-03-01

    A new method is described for measuring the Faradic resistance of a single electrode-electrolyte interface. The method employs a test (monopolar) electrode, a potential-sensing electrode and a large reference (indifferent) electrode, along with a constant-current source capable of providing a step function of current. The method was used to measure the Faradic resistance of a 0.1 cm2 platinum electrode in contact with saline (p = 150 ohm-cm) at room temperature. It was found that for both a positive and negative current pulse, the Faradic resistance decreased almost hyperbolically with increasing current density. When the reciprocal of the Faradic resistance (Gf) was plotted versus current density and the data were fit to a polynomial curve, the results showed that for the positive pulse Gf = 0.009 + 0.05J - 0.0001J2; (SEE = 0.117); for the negative pulse, Gf = 0.007 + 0.067J - 0.0001J2; (SEE = 0.028); where Gf is in millisiemens and J is in mA/cm2 for this 0.1 cm2 electrode. These relationships permit estimating the Faradic resistance (Rf) for zero current density. For the positive pulse, Rf = 111 kilohms and for the negative pulse Rf = 143 kilohms. The method is applicable to the measurement of the Faradic resistance of a wide variety of metal electrodes.

  8. A multi-pad electrode based functional electrical stimulation system for restoration of grasp

    Directory of Open Access Journals (Sweden)

    Malešević Nebojša M

    2012-09-01

    Full Text Available Abstract Background Functional electrical stimulation (FES applied via transcutaneous electrodes is a common rehabilitation technique for assisting grasp in patients with central nervous system lesions. To improve the stimulation effectiveness of conventional FES, we introduce multi-pad electrodes and a new stimulation paradigm. Methods The new FES system comprises an electrode composed of small pads that can be activated individually. This electrode allows the targeting of motoneurons that activate synergistic muscles and produce a functional movement. The new stimulation paradigm allows asynchronous activation of motoneurons and provides controlled spatial distribution of the electrical charge that is delivered to the motoneurons. We developed an automated technique for the determination of the preferred electrode based on a cost function that considers the required movement of the fingers and the stabilization of the wrist joint. The data used within the cost function come from a sensorized garment that is easy to implement and does not require calibration. The design of the system also includes the possibility for fine-tuning and adaptation with a manually controllable interface. Results The device was tested on three stroke patients. The results show that the multi-pad electrodes provide the desired level of selectivity and can be used for generating a functional grasp. The results also show that the procedure, when performed on a specific user, results in the preferred electrode configuration characteristics for that patient. The findings from this study are of importance for the application of transcutaneous stimulation in the clinical and home environments.

  9. Fast redox of composite electrode of nitroxide radical polymer and carbon with polyacrylate binder

    Science.gov (United States)

    Komaba, Shinichi; Tanaka, Tatsuya; Ozeki, Tomoaki; Taki, Takayuki; Watanabe, Hiroaki; Tachikawa, Hiroyuki

    For organic radical batteries, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) has been reported as a promising positive electrode material. The PTMA/C composite electrode prepared with polyacrylate binder demonstrated the fast redox performance for the application to aprotic secondary batteries. When the variation in discharge capacities of the PTMA/C composite electrode was tested galvanostatically at 20 C rates, the electrode retained 96% of the initial capacity after 1000 cycles. This is attributed to the fact that the redox of PTMA is a simple reaction to form the oxoammonium salt doped with ClO 4 - anions in the electrolyte. When the PTMA/C composite electrode was discharged at different C rates, the electrode retained 81% of the theoretical capacity even at 50 C rates. This remarkably high rate capability originates from the fast electron-transfer kinetic of the 2,2,6,6-tetramethylpiperidine- N-oxyl (so-called TEMPO) radical, partially jelled polyacrylate binder, and the improved conductivity throughout the electrode by thoroughly mixing with carbon.

  10. Cerebellar clear cell ependymoma in a 10 year old girl

    Energy Technology Data Exchange (ETDEWEB)

    Thinzar Aye Nyein; Moon, Ah Rim; Hwang, Sun Chul; Hong, Hyun Sook; Lee, A Leum; Chang, Kee Hyun; Kim, Hee Kyung; Chin, Su Sie [Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Park, Ji Sang [Soonchunhyang University Gumi Hospital, Gumi (Korea, Republic of)

    2016-01-15

    Clear cell ependymoma (CCE) is a histological rare variant (1–5%) of ependymoma, which is distinguished from other histological subtypes by the presence of fusiform cells arrayed radially around small blood vessels. These alleged perivascular pseudorosettes are significant characteristic features of ependymomas. About 95% of infratentorial ependymomas are found in the fourth ventricle and the remainder occurs as cerebellopontine angle lesions. In previous reports, the cerebellum is found to be a rare location for ependymoma. In this study we report one case of CCE originating from the cerebellar hemisphere, showing unusual morphology on 3T MRI.

  11. Incidentally detected clear cell renal cell carcinoma with rhabdoid differentiation.

    Science.gov (United States)

    Krishnamoorthy, Venkatesh; Gowda, Kiran Krishne; Rao, Raman Narayana

    2016-01-01

    Renal cell carcinoma with rhabdoid differentiation (RCC-R) has an aggressive biologic behavior and poor prognosis. A recent consensus statement of the International Society of Urological Pathology (ISUP) proposed a nucleolar grading system (ISUP grade) for RCC to replace Fuhrman system and recommended reporting the presence of rhabdoid differentiation and considering tumors with rhabdoid differentiation to be ISUP Grade 4. We report a case of incidentally detected clear cell RCC-R in a 52-year-old man. This is one of the earliest cases of RCC-R (pT1b) detected and first such case from Indian subcontinent.

  12. Incidentally detected clear cell renal cell carcinoma with rhabdoid differentiation

    Directory of Open Access Journals (Sweden)

    Venkatesh Krishnamoorthy

    2016-01-01

    Full Text Available Renal cell carcinoma with rhabdoid differentiation (RCC-R has an aggressive biologic behavior and poor prognosis. A recent consensus statement of the International Society of Urological Pathology (ISUP proposed a nucleolar grading system (ISUP grade for RCC to replace Fuhrman system and recommended reporting the presence of rhabdoid differentiation and considering tumors with rhabdoid differentiation to be ISUP Grade 4. We report a case of incidentally detected clear cell RCC-R in a 52-year-old man. This is one of the earliest cases of RCC-R (pT1b detected and first such case from Indian subcontinent.

  13. Polycrystalline diamond detectors with three-dimensional electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Lagomarsino, S., E-mail: lagomarsino@fi.infn.it [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Bellini, M. [INO-CNR Firenze, Largo E. Fermi 6, 50125 Firenze (Italy); Brianzi, M. [INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Carzino, R. [Smart Materials-Nanophysics, Istituto Italiano di Tecnologia, Genova, Via Morego 30, 16163 Genova (Italy); Cindro, V. [Joseph Stefan Institute, Jamova Cesta 39, 1000 Ljubljana (Slovenia); Corsi, C. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); LENS Firenze, Via N. Carrara 1, 50019 Sesto Fiorentino (Italy); Morozzi, A.; Passeri, D. [INFN Perugia, Perugia (Italy); Università degli Studi di Perugia, Dipartimento di Ingegneria, via G. Duranti 93, 06125 Perugia (Italy); Sciortino, S. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Servoli, L. [INFN Perugia, Perugia (Italy)

    2015-10-01

    The three-dimensional concept in diamond detectors has been applied, so far, to high quality single-crystal material, in order to test this technology in the best available conditions. However, its application to polycrystalline chemical vapor deposited diamond could be desirable for two reasons: first, the short inter-electrode distance of three-dimensional detectors should improve the intrinsically lower collection efficiency of polycrystalline diamond, and second, at high levels of radiation damage the performances of the poly-crystal material are not expected to be much lower than those of the single crystal one. We report on the fabrication and test of three-dimensional polycrystalline diamond detectors with several inter-electrode distances, and we demonstrate that their collection efficiency is equal or higher than that obtained with conventional planar detectors fabricated with the same material. - Highlights: • Pulsed laser fabrication of polycristalline diamond detectors with 3D electrodes. • Measurement of the charge collection efficiency (CCE) under beta irradiation. • Comparation between the CCE of 3D and conventional planar diamond sensors. • A rationale for the behavior of three-dimensional and planar sensors is given.

  14. Transcranial direct current stimulation: electrode montage in stroke.

    Science.gov (United States)

    Mahmoudi, Hooman; Borhani Haghighi, Afshin; Petramfar, Peyman; Jahanshahi, Sepehr; Salehi, Zahra; Fregni, Felipe

    2011-01-01

    Neurophysiological and computer modelling studies have shown that electrode montage is a critical parameter to determine the neuromodulatory effects of transcranial direct current stimulation (tDCS). We tested these results clinically by systematically investigating optimal tDCS electrode montage in stroke. Ten patients received in a counterbalanced and randomised order the following conditions of stimulation (i) anodal stimulation of affected M1 (primary motor cortex) and cathodal stimulation of unaffected M1 ('bilateral tDCS'); (ii) anodal stimulation of affected M1 and cathodal stimulation of contralateral supraorbital area ('anodal tDCS'); (iii) cathodal stimulation of unaffected M1 and anodal stimulation of contralateral supraorbital area ('cathodal tDCS'); (iv) anodal stimulation of affected M1 and cathodal stimulation of contralateral deltoid muscle ('extra-cephalic tDCS') and (v) sham stimulation. We used the Jebsen-Taylor Test (JTT) as a widely accepted measure of upper limb function. Bilateral tDCS, anodal tDCS and cathodal tDCS were shown to be associated with significant improvements on the JTT. Placing the reference electrode in an extracephalic position and use of sham stimulation did not induce any significant effects. This small sham controlled cross-over clinical trial is important to provide additional data on the clinical effects of tDCS in stroke and for planning and designing future large tDCS trials in patients with stroke.

  15. Solid Polymer Fuel Cells. Electrode and membrane performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S.

    1996-12-31

    This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

  16. Electrode assembly for a lithium ion battery, process for the production of such electrode assembly, and lithium ion battery comprising such electrode assemblies

    NARCIS (Netherlands)

    Mulder, F.M.; Wagemaker, M.

    2013-01-01

    The invention provides an electrode assembly for a lithium ion battery, the electrode assembly comprising a lithium storage electrode layer on a current collector, wherein the lithium storage electrode layer is a porous layer having a porosity in the range of -35 %, with pores having pore widths in

  17. Wet-spun, porous, orientational graphene hydrogel films for high-performance supercapacitor electrodes

    Science.gov (United States)

    Kou, Liang; Liu, Zheng; Huang, Tieqi; Zheng, Bingna; Tian, Zhanyuan; Deng, Zengshe; Gao, Chao

    2015-02-01

    sheets. Furthermore, three reduction methods including hydrothermal treatment, hydrazine and hydroiodic acid reduction are used to evaluate the specific capacitances of the graphene hydrogel film. Hydrazine-reduced graphene hydrogel film shows the highest capacitance of 203 F g-1 at 1 A g-1 and maintains 67.1% specific capacitance (140 F g-1) at 50 A g-1. The combination of scalable wet-spinning technology and orientational structure makes graphene hydrogel films an ideal electrode material for supercapacitors. Electronic supplementary information (ESI) available: The schematic diagram for fabricating graphene oxide hydrogel films, stress-strain curves and TGA curves of three GHFs, a digital photo of the test device for the two-electrode system, and comparison of the electrochemical performance of our GHF-HZ supercapacitors. See DOI: 10.1039/c4nr07038k

  18. Fabrication optimisation of carbon fiber electrode with Taguchi method.

    Science.gov (United States)

    Cheng, Ching-Ching; Young, Ming-Shing; Chuang, Chang-Lin; Chang, Ching-Chang

    2003-07-01

    In this study, we describe an optimised procedure for fabricating carbon fiber electrodes using Taguchi quality engineering method (TQEM). The preliminary results show a S/N ratio improvement from 22 to 30 db (decibel). The optimised parameter was tested by using a glass micropipette (0.3 mm outer/2.5 mm inner length of carbon fiber) dipped into PBS solution under 2.9 V triangle-wave electrochemical processing for 15 s, followed by coating treatment of micropipette on 2.6 V DC for 45 s in 5% Nafion solution. It is thus shown that Taguchi process optimisation can improve cost, manufacture time and quality of carbon fiber electrodes.

  19. NiO nanosheet assembles for supercapacitor electrode materials

    Institute of Scientific and Technical Information of China (English)

    Huanhao Xiao; Shunyu Yao; Hongda Liu; Fengyu Qu; Xu Zhang n; Xiang Wu n

    2016-01-01

    In this paper, large scale hierarchically assembled NiO nanosheets have been favorably fabricated through a facile hydrothermal route. The as-prepared NiO nanosheet assembles were characterized in detail by various analytical techniques. The results showed these nanosheets present the thickness of about 30 nm and the surface area is 116.9 m2 g ? 1. These NiO nanosheet assembles were used as the working electrode materials in electrochemical tests, which demonstrated a specific capacitance value of 81.67 F g ? 1 at the current density of 0.5 A g ? 1 and excellent long cycle-life stability with 78.5% of its discharge specific capacitance retention after 3000 cycles at the current density of 0.5 A g?1, revealing the as-synthesized NiO nanosheet assembles might be a promising electrode material for supercapacitor applications.

  20. Effect of Tropical Peat Swamp Forest Clearing on Soil Carbon Storage

    Directory of Open Access Journals (Sweden)

    Ahmad S.M. Nuri

    2011-01-01

    Full Text Available Problem Statement: Forest clearing in Tropical Peat Swamp Forest (TPSF will affect forest soil carbon storage. Thus this study is essential to determine whether the effect of clearing of forest does to the nature of soil forest concentrating on soil carbon storage. The objectives of this study were to analyze carbon storage values in logged and clear cut TPSF and to compare these values to see whether clearing of forest will affect its soil in terms of carbon storage. Approach: Soil sampling was conducted in July 2009 on two different plots at Batang Igan, Sibu, Sarawak, Malaysia. The plots are secondary TPSF where this area has been logged but not been cleared while another plot is the clear cut area where the forest has been cut down and cleared for other land use. Soil samples were taken in each plot in the depth of 0-15 cm. Every sample was taken randomly by peat auger using bulking method. The soils were air dried, pounded using mortar and sieved. The bulk densities were determined by coring method. Total Carbon (TC, total Organic Matter (OM, Total Nitrogen (TN and stable C estimation per hectare were determined from bulk density. The soil pH was determined using pH meter by using water and KCl. SOM, TC and stable C in Humic Acid (HA were determined by loss-on ignition method. TN was determined using Micro-Kjeldahl method followed by steam distillation and titration. HA was extracted and purified using distilled water. Then, the HA were oven dried in 40oC. The E4/E6 ratio by using spectrometer was used. Total acidity of HA which consists of carboxylic (-COOH and phenolic (-OH functional group were analyzed. The statistical analysis and comparison was using t-test to compare between two means. Results: The variables that showing the significant differences between two plots were pH water and KCl, soil OM, total C and HA yield. The insignificant differences were bulk density, total N, C/N ratio, E4/E6, phenol, carboxyl

  1. Using Shrub Clearing, Draining, and Herbivory to Control Bramble Invasion in Mediterranean Dry Grasslands

    Science.gov (United States)

    Masson, Solène; Mesléard, François; Dutoit, Thierry

    2015-10-01

    For centuries, the dry grassland of the plain of La Crau (south-eastern France) has been subjected to numerous disturbances resulting in the destruction and the fragmentation of this emblematic rangeland ecosystem of the Mediterranean. Today, this ecosystem is facing a new threat from a proliferating native species, the bramble ( Rubus ulmifolius Schott), which preferentially colonizes areas that were formerly cultivated and/or exposed to water infiltration. To identify a strategy for effective control of this colonization, in situ experiments testing disturbance regimes (shrub clearing and/or mixed grazing by sheep and goats) combined with the control of access to water resources (with or without drainage trenches) were undertaken between 2010 and 2013. Only clearing and grazing combined over 3 years led to significant changes in vegetation height and bramble cover as well as modifications in the floristic composition, diversity, similarity, and richness of the plant community. Neither a clearing operation carried out in 2010 alone, nor grazing alone, reduced bramble cover, and neither treatment increased the species richness of the plant community. Similarly, digging drainage trenches had no significant impact either on the plant community or on bramble cover. Our study suggests that only annual mechanical clearing coupled with sheep and goats grazing can significantly reduce bramble cover. This combined restoration treatment needs to be applied for at least 3 consecutive years to induce significant changes and enable this ecosystem to return to the dry grassland succession.

  2. The Effects of Opaque and Clear Pit and Fissure Sealants on Infrared Laser Fluorescence Measurements

    Science.gov (United States)

    Bahrololoomi, Z.; Khodabakhsh, M.; Khaksar, Y.

    2014-01-01

    Statement of the Problem: The purpose of placing sealants is to inhibit caries by physical closure of the pits and fissures of teeth. A device named DIAGNOdent is useful in detecting occlusal caries by employing laser fluorescence (LF). However, there are contradictory results in the influence of sealants on LF measurements. Purpose: The aim of this study is to investigate the effects of two different types of fissure sealants on LF measurements. Materials and Method: In this in vitro study, 86 extracted permanent third molars were divided randomly into two groups and clear or opaque sealant was applied on the occlusal surfaces. Two examiners performed pre- and post-seal fluorescence measurements twice with one week interval by employing DIAGNOdent device. Finally, measured values were evaluated through the statistical paired t-test by means of SPSS 17 software. Results: The mean value of LF measurements increased significantly due to the application of clear sealant (p= 0.001) while the statistical changes in this measurement was negligible after applying opaque sealant (p= 0.311). Conclusion: Clear sealants increase the LF measured values but opaque sealants cause almost no changes. Therefore, DIAGNOdent device is not reliable for detecting caries beneath the clear sealant. PMID:24883342

  3. The Effects of Opaque and Clear Pit and Fissure Sealants on Infrared Laser Fluorescence Measurements

    Directory of Open Access Journals (Sweden)

    Bahrololoomi Z.

    2013-10-01

    Full Text Available Statement of the Problem: The purpose of placing sealants is to inhibit caries by physical closure of the pits and fissures of teeth. A device named DIAGNOdent is useful in detecting occlusal caries by employing laser fluorescence (LF. However, there are contradictory results in the influence of sealants on LF measurements. Purpose: The aim of this study is to investigate the effects of two different types of fissure sealants on LF measurements. Materials and Method: In this in vitro study, 86 extracted permanent third molars were divided randomly into two groups and clear or opaque sealant was applied on the occlusal surfaces. Two examiners performed pre and post-seal fluorescence measurements twice with one week interval by employing DIAGNOdent device. Finally, measured values were evaluated through the statistical paired t-test by means of SPSS 17 software. Results: The mean value of LF measurements increased significantly due to the application of clear sealant (p= 0.001 while the statistical changes in this measurement is negligible after applying opaque sealant (p= 0.311. Conclusion: Clear sealants increase the LF measured values but opaque sealants cause almost no changes. Therefore DIAGNOdent device is not reliable for detecting caries beneath the clear sealant.

  4. Clear Cell Adenocarcinoma of the Urethra: Review of the Literature

    Directory of Open Access Journals (Sweden)

    Anthony Kodzo-Grey Venyo

    2015-01-01

    Full Text Available Background. Clear cell adenocarcinoma of the urethra (CCAU is extremely rare and a number of clinicians may be unfamiliar with its diagnosis and biological behaviour. Aims. To review the literature on CCAU. Methods. Various internet databases were used. Results/Literature Review. (i CCAU occurs in adults and in women in the great majority of cases. (ii It has a particular association with urethral diverticulum, which has been present in 56% of the patients; is indistinguishable from clear cell adenocarcinoma of the female genital tract but is not associated with endometriosis; and probably does not arise by malignant transformation of nephrogenic adenoma. (iii It is usually, readily distinguished from nephrogenic adenoma because of greater cytological a-typicality and mitotic activity and does not stain for prostate-specific antigen or prostatic acid phosphatase. (iv It has been treated by anterior exenteration in women and cystoprostatectomy in men and at times by radiotherapy; chemotherapy has rarely been given. (v CCAU is aggressive with low 5-year survival rates. (vi There is no consensus opinion of treatment options that would improve the prognosis. Conclusions. Few cases of CCAU have been reported. Urologists, gynaecologists, pathologists, and oncologists should report cases of CCAU they encounter and enter them into a multicentric trial to determine the best treatment options that would improve the prognosis.

  5. APLIKASI SIX SIGMA PADA PRODUK CLEAR FILE DI PERUSAHAAN STATIONARY

    Directory of Open Access Journals (Sweden)

    Desy Emilasari

    2007-01-01

    Full Text Available This paper describes the application of the Six Sigma methods is used in order to improve quality in manufacturing company that produce stationary product. DMAIC approach is utilized to analyze and improve 'Pocket Clear File' product since this product has more variability and defects. Quality improvement also monitor the process that influenced pocket defect in Bag Making, Kami-ire, Karidome, and Pocket after Karidome Inspections section. Determining of Six Sigma project is based in process and defect type in each section. FMEA also gave the recommendation for quality improvement we need to evaluate the final result of the improvement since some of them were not working properly. Abstract in Bahasa Indonesia : Paper ini menggambarkan bagaimana aplikasi metode Six Sigma digunakan untuk melakukan perbaikan kualitas pada perusahaan manufaktur yang memproduksi produk stationary. Pendekatan DMAIC dipakai untuk menganalisa dan melakukan perbaikan produk 'Pocket Clear File' karena tingginya variabilitas dan cacat dibanding produk lain. Perbaikan kualitas juga memperhatikan proses yang mempengaruhi terjadinya cacat pocket pada section Bag Making, Kami-ire, Karidome, dan Pocket after Karidome Inspection. Penentuan proyek Six Sigma didasarkan atas proses dan jenis cacat pada setiap section. Pendekatan FMEA mampu memberi rekomendasi perbaikan kualitas. Evaluasi dari hasil perbaikan penting untuk dilakukan karena beberapa implementasi perbaikan kualitas tidak berjalan sesuai dengan rencana. kata kunci: six sigma, DMAIC, perusahaan stationary.

  6. Primary abdominal wall clear cell carcinoma arising from incisional endometriosis

    Institute of Scientific and Technical Information of China (English)

    Burcu Gundogdu; Isin Ureyen; Gunsu Kimyon; Hakan Turan; Nurettin Boran; Gokhan Tulunay; Dilek Bulbul; Taner Turan; M Faruk Kose

    2013-01-01

    A 49 year-old patient with the complaint of a mass located in the caesarean scar was admitted. There was a fixed mass 30í30 mm in diameter with regular contour located at the right corner of the pfannenstiel incision. Computed tomography revealed a (40í50í50) mm solid mass lesion with margins that cannot be distinguished from the uterus, bladder and small intestines and a heterogeneous mass lesion (50í45í55) mm in diameter, located in the right side of the anterior abdominal wall. Cytoreductive surgery including total abdominal hysterectomy and bilateral salpingo-oophorectomy was performed. Final pathology was clear cell carcinoma. Clear cell carcinoma arising from an extraovarian endometriotic focus was diagnosed and the patient received 6 cycles paclitaxel-carboplatin chemotherapy as adjuvant treatment. The patient who was lost to follow-up applied to our clinic 2 years after surgery with a recurrent mass in the left inguinal region. After 3 cycles of chemotherapy, the patient's tumoral mass in the left inguinal region was excised. The result of the pathology was carcinoma metastasis. It is decided that the following treatment of the patient should be palliative radiation therapy. The patient who underwent palliative radiation therapy died of disease after 4 months of the second operation.

  7. Code Generation for Embedded Software for Modeling Clear Box Structures

    Directory of Open Access Journals (Sweden)

    V. Chandra Prakash

    2011-09-01

    Full Text Available Cleanroom software Engineering (CRSE recommended that the code related to the Application systems be generated either manually or through code generation models or represents the same as a hierarchy of clear box structures. CRSE has even advocated that the code be developed using the State models that models the internal behavior of the systems. No framework has been recommended by any Author using which the Clear boxes are designed using the code generation methods. Code Generation is one of the important quality issues addressed in cleanroom software engineering. It has been investigated that CRSE can be used for life cycle management of the embedded systems when the hardware-software co-design is in-built as part and parcel of CRSE by way of adding suitable models to CRSE and redefining the same. The design of Embedded Systems involves code generation in respect of hardware and Embedded Software. In this paper, a framework is proposed using which the embedded software is generated. The method is unique that it considers various aspects of the code generation which includes Code Segments, Code Functions, Classes, Globalization, Variable propagation etc. The proposed Framework has been applied to a Pilot project and the experimental results are presented.

  8. MODIS Observations of Enhanced Clear Sky Reflectance Near Clouds

    Science.gov (United States)

    Varnai, Tamas; Marshak, Alexander

    2009-01-01

    Several recent studies have found that the brightness of clear sky systematically increases near clouds. Understanding this increase is important both for a correct interpretation of observations and for improving our knowledge of aerosol-cloud interactions. However, while the studies suggested several processes to explain the increase, the significance of each process is yet to be determined. This study examines one of the suggested processes three-dimensional (3-D) radiative interactions between clouds and their surroundings by analyzing a large dataset of MODIS (Moderate Resolution Imaging Spectroradiometer) observations over the Northeast Atlantic Ocean. The results indicate that 3-D effects are responsible for a large portion of the observed increase, which extends to about 15 km away from clouds and is stronger (i) at shorter wavelengths (ii) near optically thicker clouds and (iii) near illuminated cloud sides. This implies that it is important to account for 3-D radiative effects in the interpretation of solar reflectance measurements over clear regions in the vicinity of clouds.

  9. Genetic characteristics of the non-clear cell renal cancer

    Directory of Open Access Journals (Sweden)

    D. S. Mikhaylenko

    2016-01-01

    Full Text Available Renal cancer (RC is one of the most frequent diseases in oncological urology; the most common form of RC is the clear cell carcinoma. However, percentage of less-studied non-clear cell RC (nccRC reaches up to 25 % of cases suggesting further studying, improvement of diagnosis and treatment of these tumors. The key events of carcinogenesis are genetic alterations including chromosomal aberrations and point mutations in proto-oncogenes and tumor suppressor genes. This review describes cytogenetic aberrations in the context of nccRC diversity according to the current ISUP classification. Translocation variants of nccRC (MiT-RC were characterized separately as particular cases of the chromosome rearrangements involving MiT gene family (TFE3, TFEB, MITF. In addition, the main nccRC hereditary forms caused by germinal mutations in the genes FLCN, FH, and MET, as well as recent studies of sporadic tumors with using the next generation sequencing techniques were reviewed. These experiments were designed to search for somatic mutations throughout the tumor genome or exom and revealed the different mutational profiles of I/II papillary RC subtypes, chromophobe carcinoma versus oncocytoma. The review may be informative for oncologists, urologists, geneticists and specialists in related sciences. 

  10. A Nafion®-based co-planar electrode amperometric sensor for methanol determination in the gas phase

    Indian Academy of Sciences (India)

    K Wallgren; S Sotiropoulos

    2009-09-01

    A co-planar electrode device, fabricated with all electrodes (working, counter and reference) on the same face of a Nafion® polymer electrolyte membrane, is proposed for the amperometric detection of gaseous methanol using Pt as the working electrode. Clear voltammetry is obtained for methanol oxidation from its vapours in equilibrium with methanol aqueous solutions, both in the absence and presence of oxygen in the gas stream. Using an appropriate pulse sequence to keep the indicator electrode active, methanol vapours in the 1-13 Torr partial pressure range (in equilibrium with methanol aqueous solutions in the 1-10% w/w concentration range) could be determined, in a constant potential, amperometric mode. The methanol detector could be operated both in a nitrogen stream and (in what is essential for practical applications) in an air atmosphere too, with estimated detection limits of 1.2 and 1.4 Torr respectively.

  11. Size dependent electrochemical detection of trace heavy metal ions based on nano-patterned carbon sphere electrodes

    Science.gov (United States)

    Zhang, Lu-Hua; Li, Wen-Cui; Yan, Dong; Wang, Hua; Lu, An-Hui

    2016-07-01

    The challenge in efficient electrochemical detection of trace heavy metal ions (HMI) for early warning is to construct an electrode with a nano-patterned architecture. In this study, a range of carbon electrodes with ordered structures were fabricated using colloidal hollow carbon nanospheres (HCSs) as sensing materials for trace HMI (represented by Pb(ii)) detection by square wave anodic stripping voltammetry. The regular geometrical characteristics of the carbon electrode allow it to act as a model system for the estimation of electron transfer pathways by calculating contact points between HCSs and a glassy carbon electrode. A clear correlation between the contact points and the electron transfer resistance has been established, which fits well with the quadratic function model and is dependent on the size of HCSs. To our knowledge, this is the first clear function that expresses the structure-sensing activity relationship of carbon-based electrodes. The prepared carbon electrode is capable of sensing Pb(ii) with a sensitivity of 0.160 μA nM-1, which is much higher than those of other electrodes reported in the literature. Its detection limit of 0.6 nM is far below the guideline value (72 nM) given by the US Environmental Protection Agency. In addition, the carbon electrode could be a robust alternative to various heavy metal sensors.The challenge in efficient electrochemical detection of trace heavy metal ions (HMI) for early warning is to construct an electrode with a nano-patterned architecture. In this study, a range of carbon electrodes with ordered structures were fabricated using colloidal hollow carbon nanospheres (HCSs) as sensing materials for trace HMI (represented by Pb(ii)) detection by square wave anodic stripping voltammetry. The regular geometrical characteristics of the carbon electrode allow it to act as a model system for the estimation of electron transfer pathways by calculating contact points between HCSs and a glassy carbon electrode. A

  12. Reduction of graphene oxide nanosheets by natural beta carotene and its potential use as supercapacitor electrode

    Directory of Open Access Journals (Sweden)

    Rubaiyi M. Zaid

    2015-07-01

    Full Text Available A green, non-toxic and eco-friendly approach for the reduction of graphene oxide (GO nanosheets using natural β-carotene is reported. The FTIR spectroscopy and thermogravimetric analyses reveal the oxygen scavenging property of β-carotene successfully removes oxygen functionalities on GO nanosheets. Complete GO reduction is achieved within 16 h with 10 mM β-carotene as confirmed by the UV spectroscopy results. The high resolution transmission electron microscopy images provide clear evidence for the formation of few layers of graphene nanosheets. Furthermore, the mechanism of GO reduction by β-carotene has been proposed in this study. The electrochemical testing shows good charge storage properties of β-carotene reduced GO (142 F/g at 10 mV/s; 149 F/g at 1 A/g in Na2SO4, with stable cycling (89% for up to 1000 cycles. The findings suggest the reduction of GO nanosheets by β-carotene is a suitable approach in producing graphene nanosheets for supercapacitor electrode.

  13. Nanoscale Chemical Evolution of Silicon Negative Electrodes Characterized by Low-Loss STEM-EELS

    CERN Document Server

    Boniface, Maxime; Danet, Julien; Guyomard, Dominique; Moreau, Philippe; Bayle-Guillemaud, Pascale

    2016-01-01

    Continuous solid electrolyte interface (SEI) formation remains the limiting factor of the lifetime of silicon nanoparticles (SiNPs) based negative electrodes. Methods that could provide clear diagnosis of the electrode degradation are of utmost necessity to streamline further developments. We demonstrate that electron energy-loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) can be used to quickly map SEI components and quantify LixSi alloys from single experiments, with resolutions down to 5 nm. Exploiting the low-loss part of the EEL spectrum allowed us to circumvent the degradation phenomena that have so far crippled the application of this technique on such beam-sensitive compounds. Our results provide unprecedented insight into silicon aging mechanisms in full cell configuration. We observe the morphology of the SEI to be extremely heterogeneous at the particle scale but with clear chemical evolutions with extended cycling coming from both SEI accumulation and a transition fro...

  14. Study on quality of resistance spot welded aluminum alloys under various electrode pressures

    Institute of Scientific and Technical Information of China (English)

    San-san AO; Zhen LUO; Xin-xin TANG; Lin-shu ZHOU; Shu-xian YUAN; Rui WANG; Kai-lei SONG; Xing-zheng BU; Xiao-yi LI; Zhi-qing XUE

    2009-01-01

    The electrode force is One of the main parameters in resistance spot welding (RSW). It is very important to guarantee the quality of aluminum alloys and determine whether the electrode pressure is stable or adjustable in the welding process. With the drive set of a servo-motor, we conduct the RSW tests and tensile shear tests on the 5052 aluminum alloy sheets. Results of these tests show that all variable pressure curves are suitable for spot welding, and all have their own rules in affecting the tensile strength of the spot welded joints.

  15. Joint CARE-ELAN, CARE-HHH-APD, and EUROTEV-WP3 Workshop on Electron Cloud Clearing

    CERN Document Server

    Scandale, Walter; Schulte, D; Zimmermann, F; Electron Cloud Effects and Technological Consequences; ECL2

    2007-01-01

    This report contains the Proceedings of the joint CARE-HHH-APD, CARE-ELAN, and EUROTEV-WP3 Mini-Workshop on 'Electron Cloud Clearing - Electron Cloud and Technical Consequences', "ECL2", held at CERN in Geneva, Switzerland, 1-2 March 2007). The ECL2 workshop explored novel technological remedies against electron-cloud formation in an accelerator beam pipe. A primary motivation for the workshop was the expected harmful electron-cloud effects in the upgraded LHC injectors and in future linear colliders, as well as recent beam observations in operating facilities like ANKA, CESR, KEKB, RHIC, and SPS. The solutions discussed at ECL2 included enamel-based clearing electrodes, slotted vacuum chambers, NEG coating, and grooves. Several of the proposed cures were assessed in terms of their clearing efficiency and the associated beam impedance. The workshop also reviewed new simulation tools like the 3D electron-ion build-up 'Faktor', modeling assumptions, analytical calculations, beam experiments, and laboratory meas...

  16. Nanostructured Solid Oxide Fuel Cell Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sholklapper, Tal Zvi [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

  17. Comment on 'The characterization of doped CeO2 electrodes in solid oxide fuel cells' by B.G. Pound

    DEFF Research Database (Denmark)

    Ranløv, J.; Poulsen, F.W.; Mogensen, Mogens Bjerg

    1993-01-01

    Electrode tests and ac impedance measurements presented by Pound on Ni, Co and Mn doped CeO2 are reviewed. We find that the stability of solid solutions in the systems of NiO-CeO2 and CoO-CeO2 are improbable and that therefore the interpretation of ac impedance data and electrode tests should...

  18. Metalless electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips.

    Science.gov (United States)

    Duarte Junior, Gerson F; Fracassi da Silva, José Alberto; Mendonça Francisco, Kelliton José; do Lago, Claudimir Lucio; Carrilho, Emanuel; Coltro, Wendell K T

    2015-08-01

    This paper describes the use of ionic solutions as sensing electrodes for capacitively coupled contactless conductivity detection on electrophoresis microchips. Initially, two channels were engraved in a PMMA holder by using a CO2 laser system and sealed with a thin adhesive membrane. PDMS electrophoresis chips were fabricated by soft lithography and reversibly sealed against the polymer membrane. Different ionic solutions were investigated as metalless electrodes. The electrode channels were filled with KCl solutions prepared in conductivity values from approximately 10 to 40 S/m. The best analytical response was achieved using the KCl solution with 21.9 S/m conductivity (2 mol/L). Besides KCl, we also tested NaCl and LiCl solutions for actuating as detection electrodes. Taking into account the same electrolyte concentration (2 mol/L), the best response was recorded with KCl solution due to its higher ionic conductivity. The optimum operating frequency (400 kHz) and the best sensing electrode (2 mol/L KCl) were used to monitor electrophoretic separations of a mixture containing K(+) , Na(+) , and Li(+) . The use of liquid solutions as sensing electrodes for capacitively coupled contactless conductivity detection measurements has revealed great performance to monitor separations on chip-based devices, avoiding complicated fabrication schemes to include metal deposition and encapsulation of electrodes. The LOD values were estimated to be 28, 40, and 58 μmol/L for K(+) , Na(+) , and Li(+) , respectively, what is comparable to that of conventional metal electrodes. When compared to the use metal electrodes, the proposed approach offers advantages regarding the easiness of fabrication, simplicity, and lower cost per device.

  19. Implanted neural electrodes cause chronic, local inflammation that is correlated with local neurodegeneration

    Science.gov (United States)

    McConnell, George C.; Rees, Howard D.; Levey, Allan I.; Gutekunst, Claire-Anne; Gross, Robert E.; Bellamkonda, Ravi V.

    2009-10-01

    Prosthetic devices that are controlled by intracortical electrodes recording one's 'thoughts' are a reality today, and no longer merely in the realm of science fiction. However, widespread clinical use of implanted electrodes is hampered by a lack of reliability in chronic recordings, independent of the type of electrodes used. One major hypothesis has been that astroglial scar electrically impedes the electrodes. However, there is a temporal discrepancy between stabilization of scar's electrical properties and recording failure with recording failure lagging by 1 month. In this study, we test a possible explanation for this discrepancy: the hypothesis that chronic inflammation, due to the persistent presence of the electrode, causes a local neurodegenerative state in the immediate vicinity of the electrode. Through modulation of chronic inflammation via stab wound, electrode geometry and age-matched control, we found that after 16 weeks, animals with an increased level of chronic inflammation were associated with increased neuronal and dendritic, but not axonal, loss. We observed increased neuronal and dendritic loss 16 weeks after implantation compared to 8 weeks after implantation, suggesting that the local neurodegenerative state is progressive. After 16 weeks, we observed axonal pathology in the form of hyperphosphorylation of the protein tau in the immediate vicinity of the microelectrodes (as observed in Alzheimer's disease and other tauopathies). The results of this study suggest that a local, late onset neurodegenerative disease-like state surrounds the chronic electrodes and is a potential cause for chronic recording failure. These results also inform strategies to enhance our capability to attain reliable long-term recordings from implantable electrodes in the CNS.

  20. Detection of nicotine based on molecularly imprinted TiO{sub 2}-modified electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.-T.; Chen, P.-Y.; Chen, J.-G.; Suryanarayanan, Vembu [Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Ho, K.-C. [Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China)], E-mail: kcho@ntu.edu.tw

    2009-02-02

    Amperometric detection of nicotine (NIC) was carried out on a titanium dioxide (TiO{sub 2})/poly(3,4-ethylenedioxythiophene) (PEDOT)-modified electrode by a molecular imprinting technique. In order to improve the conductivity of the substrate, PEDOT was coated onto the sintered electrode by in situ electrochemical polymerization of the monomer. The sensing potential of the NIC-imprinted TiO{sub 2} electrode (ITO/TiO{sub 2}[NIC]/PEDOT) in a phosphate-buffered saline (PBS) solution (pH 7.4) containing 0.1 M KCl was determined to be 0.88 V (vs. Ag/AgCl/saturated KCl). The linear detection range for NIC oxidation on the so-called ITO/TiO{sub 2}[NIC]/PEDOT electrode was 0-5 mM, with a sensitivity and limit of detection of 31.35 {mu}A mM{sup -1} cm{sup -2} and 4.9 {mu}M, respectively. When comparing with the performance of the non-imprinted one, the sensitivity ratio was about 1.24. The sensitivity enhancement was attributed to the increase in the electroactive area of the imprinted electrode. The at-rest stability of the ITO/TiO{sub 2}[NIC]/PEDOT electrode was tested over a period of 3 days. The current response remained about 85% of its initial value at the end of 2 days. The ITO/TiO{sub 2}[NIC]/PEDOT electrode showed reasonably good selectivity in distinguishing NIC from its major interferent, (-)-cotinine (COT). Moreover, scanning electrochemical microscopy (SECM) was employed to elucidate the surface morphology of the imprinted and non-imprinted electrodes using Fe(CN){sub 6}{sup 3-}/Fe(CN){sub 6}{sup 4-} as a redox probe on a platinum tip. The imprinted electrode was further characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR)

  1. Coated magnetic particles in electrochemical systems: Synthesis, modified electrodes, alkaline batteries, and paste electrodes

    Science.gov (United States)

    Unlu, Murat

    Magnetic field effects on electrochemical reactions have been studied and shown to influence kinetics and dynamics. Recently, our group has introduced a novel method to establish magnetic field effects by incorporating inert, magnetic microparticles onto the electrode structure. This modification improved several electrochemical systems including modified electrodes, alkaline batteries, and fuel cells. This dissertation describes the applicability of magnetic microparticles and the understanding of magnetic field effects in modified electrodes, alkaline batteries, and paste electrodes. Magnetic effects are studied on electrodes that are coated with an ion exchange polymer that embeds chemically inert, commercial, magnetic microparticles. The flux (electrolysis current) of redox probe to the magnetically modified system is compared to a similar non-magnetic electrode. Flux enhancements of 60% are achieved at magnetically modified electrode as compared to non-magnetic controls. In addition to modifying electrode surfaces, the incorporation of magnetic microparticles into the electrode material itself establishes a 20% increase in flux. Possible magnetic field effects are evaluated. Study of samarium cobalt modified electrolytic manganese dioxide, EMD electrodes further establish a magnetic effect on alkaline cathode performance. Magnetic modification improves alkaline battery performance in primary and secondary applications. The reaction mechanism is examined through voltammetric methods. This work also includes coating protocols to produce inert magnetic microparticles with high magnetic content. Magnetite powders are encapsulated in a polymer matrix by dispersion polymerization. Composite particles are examined in proton exchange membrane fuel cells to study carbon monoxide tolerance.

  2. Effect of electrode fabrication methods on the electrode performance for ethanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yuan-Hang; Li, Hui-Cheng; Yang, Hou-Hua; Zhang, Xin-Sheng; Zhou, Xing-Gui; Yuan, Wei-Kang [State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237 (China); Niu, Li [State Key Laboratory of Electroanalytical Chemistry, Chang Chun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2011-01-01

    Two palladium/carbon nanofibers modified glassy carbon electrodes, Pd/CNFs/GC-C and Pd/CNFs/GC-E, are fabricated by the conventional powder type method and by the electrophoretic deposition in conjunction with pulse electrodeposition method, respectively. Field emission scanning electron microscopy and high resolution transmission electron microscopy reveal that Pd particles are uniformly dispersed on the two electrodes and X-ray diffraction shows the average Pd particle size of the Pd/CNFs/GC-E electrode is slightly larger than that of the Pd/CNFs/GC-C electrode. Cyclic voltammetric analysis shows that the electrocatalytic activity of Pd/CNFs/GC-E electrode is better than that of Pd/CNFs/GC-C electrode for ethanol oxidation in alkaline media, although the latter has higher Pd loading than the former. This is believed to be due to the higher utilization of Pd catalyst on Pd/CNFs/GC-E electrode than on Pd/CNFs/GC-C electrode, which is confirmed by the electrochemically active surface area measurements. In addition, chronopotentiometric analysis shows the long-term operation stability of Pd/CNFs/GC-E electrode is better than that of Pd/CNFs/GC-C electrode. (author)

  3. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    Science.gov (United States)

    O'Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-08-01

    Microneedle-based ‘dry’ electrodes have immense potential for use in diagnostic procedures such as electrocardiography (ECG) analysis, as they eliminate several of the drawbacks associated with the conventional ‘wet’ electrodes currently used for physiological signal recording. To be commercially successful in such a competitive market, it is essential that dry electrodes are manufacturable in high volumes and at low cost. In addition, the topographical nature of these emerging devices means that electrode performance is likely to be highly dependent on the quality of the skin-electrode contact. This paper presents a low-cost, wafer-level micromoulding technology for the fabrication of polymeric ECG electrodes that use microneedle structures to make a direct electrical contact to the body. The double-sided moulding process can be used to eliminate post-process via creation and wafer dicing steps. In addition, measurement techniques have been developed to characterize the skin-electrode contact force. We perform the first analysis of signal-to-noise ratio dependency on contact force, and show that although microneedle-based electrodes can outperform conventional gel electrodes, the quality of ECG recordings is significantly dependent on temporal and mechanical aspects of the skin-electrode interface.

  4. Capillary suspensions as beneficial formulation concept for high energy density Li-ion battery electrodes

    Science.gov (United States)

    Bitsch, Boris; Gallasch, Tobias; Schroeder, Melanie; Börner, Markus; Winter, Martin; Willenbacher, Norbert

    2016-10-01

    We introduce a novel formulation concept to prepare high capacity graphite electrodes for lithium ion batteries. The concept is based on the capillary suspension phenomenon: graphite and conductive agent are dispersed in an aqueous binder solution and the organic solvent octanol is added as immiscible, secondary fluid providing the formation of a sample-spanning network resulting in unique stability and coating properties. No additional processing steps compared to conventional slurry preparation are required. The resulting ultra-thick electrodes comprise mass loadings of about 16.5 mg cm-2, uniform layer thickness, and superior edge contours. The adjustment of mechanical energy input ensures uniform distribution of the conductive agent and sufficient electronic conductivity of the final dry composite electrode. The resulting pore structure is due to the stable network provided by the secondary fluid which evaporates residue-free during drying. Constant current-constant potential (CC-CP) cycling clearly indicates that the corresponding microstructure significantly improves the kinetics of reversible Li+ (de-) intercalation. A double layer electrode combining a conventionally prepared layer coated directly onto the Cu current collector with an upper layer stabilized with octanol was prepared applying wet-on-wet coating. CC-CP cycling data confirms that staged porosity within the electrode cross section results in superior electrochemical performance.

  5. Use of Digital Image Technology to 'Clearly' Depict Global Change

    Science.gov (United States)

    Molnia, B. F.; Carbo, C. L.

    2014-12-01

    Earth is dynamic and beautiful. Understanding why, when, how, and how fast its surface changes yields information and serves as a source of inspiration. The artistic use of geoscience information can inform the public about what is happening to their planet in a non-confrontational and apolitical way. While individual images may clearly depict a landscape, photographic comparisons are necessary to clearly capture and display annual, decadal, or century-scale impacts of climate and environmental change on Earth's landscapes. After years of effort to artistically communicate geoscience concepts with unenhanced individual photographs or pairs of images, the authors have partnered to maximize this process by using digital image enhancement technology. This is done, not to manipulate the inherent artistic content or information content of the photographs, but to insure that the comparative photo pairs produced are geometrically correct and unambiguous. For comparative photography, information-rich historical photographs are selected from archives, websites, and other sources. After determining the geographic location from which the historical photograph was made, the original site is identified and eventually revisited. There, the historical photos field of view is again photographed, ideally from the original location. From nearly 250 locations revisited, about 175 pairs have been produced. Every effort is made to reoccupy the original historical site. However, vegetation growth, visibility reduction, and co-seismic level change may make this impossible. Also, inherent differences in lens optics, camera construction, and image format may result in differences in the geometry of the new photograph when compared to the old. Upon selection, historical photos are cleaned, contrast stretched, brightness adjusted, and sharpened to maximize site identification and information extraction. To facilitate matching historical and new images, digital files of each are overlain in

  6. Temporal co-registration for TROPOMI cloud clearing

    Directory of Open Access Journals (Sweden)

    I. Genkova

    2011-10-01

    Full Text Available The TROPOspheric Monitoring Instrument (TROPOMI is planed for launch in 2014 on board of the Sentinel 5 Precursor (S5P and is anticipated to provide high-quality and timely information on the global atmospheric composition for climate and air quality applications. TROPOMI will observe key atmospheric constituents such as ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, methane, formaldehyde and aerosol properties. The retrieval algorithms for the anticipated products require cloud information on a pixel basis. Most of them will use the cloud properties derived from TROPOMI's own measurements, such as the O2 A-band measurements. However, the methane and the aerosol retrievals require very precise cloud clearing, which is difficult to achieve at the TROPOMI spatial resolution (7 × 7 km2 and without thermal IR measurements. The current payload of the Sentinel 5 Precursor (S-5P does not include a cloud imager, thus it is planned to fly the S5P mission in a constellation with another instrument yielding an accurate cloud mask. The cloud imagery data will be provided by the US NPOESS Preparatory Project (NPP mission which will have the Visible Infrared Imager Radiometer Suite (VIIRS on board (Scalione, 2004. VIIRS will have 22 bands in the VIS and IR spectral ranges, and will deliver data with two spatial resolutions: imagery resolution bands with a nominal pixel size of 370 m at nadir, and moderate resolution bands with nominal pixel size 740 m at nadir. The instrument is combining fine spatial resolution with high-accuracy calibration similar or superior to AVHRR.

    This paper presents results from investigating the temporal co-registration requirements for suitable time differences between the VIIRS measurements of clouds and the TROPOMI methane and aerosol measurements, so that the former could be used for cloud clearing. The temporal co-registration is studied using Meteosat Second Generation (MSG Spinning

  7. Plasma Flow and Temperature in a Gliding Reactor with Different Electrode Configurations

    Directory of Open Access Journals (Sweden)

    J. Sláma

    2012-01-01

    Full Text Available This paper deals with the plasma flow shape depending on the electrode form of a gliding discharge plasma-chemical reactor, and with the temperature distribution along the direction of the plasma flow in one specific electrode form. The shape of the electrodes and their mutual position has a significant influence on the design of a gliding discharge reactor and its applications. It is crucial to know the temperature distribution in the reactor’s chamber design and discharge application. Three configurations with model shapes of wire electrodes were therefore tested (low-divergent, circular, high-divergent and the plasma flow was described. The experiments were performed in air at atmospheric pressure and at room temperature. In order to map the reactive plasma region of the flow we investigated the visible spectral lines that were emitted. The gas temperature was measured using an infrared camera.

  8. Characteristics of graphite felt electrode electrochemically oxidized for vanadium redox battery application

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-gang; HUANG Ke-long; LIU Su-qin; TAN Ning; CHEN Li-quan

    2007-01-01

    The graphite felt was oxidized at a positive electrode potential in sulfuric acid solution. The electrochemical performance of the treated graphite felt served as electrode for vanadium redox battery was investigated with FT-IR, SEM, XPS, BET, cyclic voltammetry and testing VRB system, respectively. The results show that the molar ratio of O to C increases from 0.085 to 0.15 due to the increase of -COOH functional groups during electrochemical oxidation treatment, and the GF surface is eroded by electrochemical oxidation, resulting in the surface area increase from 0.33 m2/g to 0.49 m2/g. The VRB with modified GF electrode exhibits excellent performance under a current density of 30 mA/cm2. The average current efficiency reaches 94% and average voltage efficiency reaches 85%. The improvement of electrochemical activity for the electrode is ascribed to the increase of the number of -COOH group and the special surface of GF.

  9. Electrical characterization of conductive textile materials and its evaluation as electrodes for venous occlusion plethysmography.

    Science.gov (United States)

    Goy, C B; Dominguez, J M; Gómez López, M A; Madrid, R E; Herrera, M C

    2013-08-01

    The ambulatory monitoring of biosignals involves the use of sensors, electrodes, actuators, processing tools and wireless communication modules. When a garment includes these elements with the purpose of recording vital signs and responding to specific situations it is call a 'Smart Wearable System'. Over the last years several authors have suggested that conductive textile material (e-textiles) could perform as electrode for these systems. This work aims at implementing an electrical characterization of e-textiles and an evaluation of their ability to act as textile electrodes for lower extremity venous occlusion plethysmography (LEVOP). The e-textile electrical characterization is carried out using two experimental set-ups (in vitro evaluation). Besides, LEVOP records are obtained from healthy volunteers (in vivo evaluation). Standard Ag/AgCl electrodes are used for comparison in all tests. Results shown that the proposed e-textiles are suitable for LEVOP recording and a good agreement between evaluations (in vivo and in vitro) is found.

  10. Combination of a novel electrode material and artificial mediators to enhance power generation in an MFC.

    Science.gov (United States)

    Taskan, Ergin; Ozkaya, Bestamin; Hasar, Halil

    2015-01-01

    This study focuses on two main aspects: developing a novel cost-effective electrode material and power production from domestic wastewater using three different mediators. Methylene blue (MB), neutral red (NR) and 2-hydroxy-1,4-naphthoquinone (HNQ) were selected as electrode mediators with different concentrations. A tin-coated copper mesh electrode was tested as anode electrode. Maximum power density of the microbial fuel cell (MFC) with 300 μM MB was 636 mW/m². Optimal mediator concentrations with respect to the achieved maximum power output for MB, NR and HNQ were 300 μM, 200 μM and 50 μM, respectively. The results demonstrate that tin-coated copper mesh showed a higher biocompatibility and electrical conductivity.

  11. XPS investigations of electrolyte/electrode interactions for various Li-ion battery materials

    Energy Technology Data Exchange (ETDEWEB)

    Oswald, S.; Mikhailova, D.; Scheiba, F.; Reichel, P.; Fiedler, A.; Ehrenberg, H. [IFW Dresden, Dresden (Germany)

    2011-05-15

    For future Li-ion battery applications the search for both new design concepts and materials is necessary. The electrodes of the batteries are always in contact with electrolytes, which are responsible for the transport of Li ions during the charging and discharging process. A broad range of materials is considered for both electrolytes and electrodes so that very different chemical interactions between them can occur, while good cycling behavior can only be obtained for stable solid-electrolyte interfaces. X-ray photoelectron spectroscopy (XPS) was used to study the most relevant interactions between various electrode materials in contact with different electrolyte solutions. It is shown how XPS can provide useful information on reactivities and thus preselect suitable electrode/electrolyte combinations, prior to electrochemical performance tests. (orig.)

  12. Bristle-sensors—low-cost flexible passive dry EEG electrodes for neurofeedback and BCI applications

    Science.gov (United States)

    Grozea, Cristian; Voinescu, Catalin D.; Fazli, Siamac

    2011-04-01

    In this paper, we present a new, low-cost dry electrode for EEG that is made of flexible metal-coated polymer bristles. We examine various standard EEG paradigms, such as capturing occipital alpha rhythms, testing for event-related potentials in an auditory oddball paradigm and performing a sensory motor rhythm-based event-related (de-) synchronization paradigm to validate the performance of the novel electrodes in terms of signal quality. Our findings suggest that the dry electrodes that we developed result in high-quality EEG recordings and are thus suitable for a wide range of EEG studies and BCI applications. Furthermore, due to the flexibility of the novel electrodes, greater comfort is achieved in some subjects, this being essential for long-term use.

  13. Bristle-sensors--low-cost flexible passive dry EEG electrodes for neurofeedback and BCI applications.

    Science.gov (United States)

    Grozea, Cristian; Voinescu, Catalin D; Fazli, Siamac

    2011-04-01

    In this paper, we present a new, low-cost dry electrode for EEG that is made of flexible metal-coated polymer bristles. We examine various standard EEG paradigms, such as capturing occipital alpha rhythms, testing for event-related potentials in an auditory oddball paradigm and performing a sensory motor rhythm-based event-related (de-) synchronization paradigm to validate the performance of the novel electrodes in terms of signal quality. Our findings suggest that the dry electrodes that we developed result in high-quality EEG recordings and are thus suitable for a wide range of EEG studies and BCI applications. Furthermore, due to the flexibility of the novel electrodes, greater comfort is achieved in some subjects, this being essential for long-term use.

  14. As clear as mud: Turbidity induces behavioral changes in the African cichlid Pseudocrenilabrus multicolor

    Directory of Open Access Journals (Sweden)

    Suzanne M. GRAY, Laura H. McDONNELL, Fabio G. CINQUEMANI,Lauren J. CHAPMAN

    2012-02-01

    Full Text Available Aquatic biodiversity is being lost at an unprecedented rate. One factor driving this loss is increased turbidity, an environmental stressor that can impose behavioral, morphological, and/or physiological costs on fishes. Here we describe the behavioral response of a widespread African cichlid, Pseudocrenilabrus multicolor victoriae, to turbidity. We used a split-brood rearing design to test if F1 offspring reared in turbid water, originating from river (turbid and swamp (clear populations, behave differently than full-sibs reared in clear water. We examined two facets of behavior: (1 behaviors of fish in full sib groups, including activity level and social dynamics collected during the rearing period; and (2 male aggressive behavior directed at potential male competitors after fish had reached maturity; this was done in an experimental set-up independent of the rearing aquaria. Regardless of population of origin, fish reared in turbid water were marginally less active and performed fewer social behaviors than those reared in clear water. On the other hand, when tested against a competitor in turbid water, males performed more aggressive behaviors, regardless of population of origin or rearing environment. Our results suggest a plastic behavioral response to turbidity that may allow P. multicolor to persist over a range of turbidity levels in nature by decreasing activity and general social behaviors and intensifying reproductive behaviors to ensure reproductive success [Current Zoology 58 (1: 146–157, 2012].

  15. As clear as mud: Turbidity induces behavioral changes in the African cichlid Pseudocrenilabrus multicolor

    Institute of Scientific and Technical Information of China (English)

    Suzanne M. GRAY; Laura H. McDONNELL; Fabio G. CINQUEMANI; Lauren J. CHAPMAN

    2012-01-01

    Aquatic biodiversity is being lost at an unprecedented rate.One factor driving this loss is increased turbidity,an environmental stressor that can impose behavioral,morphological,and/or physiological costs on fishes.Here we describe the behavioral response of a widespread African cichlid,Pseudocrenilabrus multicolor victoriae,to turbidity.We used a split-brood rearing design to test if F1 offspring reared in turbid water,originating from river (turbid) and swamp (clear) populations,behave differently than full-sibs reared in clear water.We examined two facets of behavior:(1) behaviors of fish in full sib groups,including activity level and social dynamics collected during the rearing period; and (2) male aggressive behavior directed at potential male competitors after fish had reached maturity; this was done in an experimental set-up independent of the rearing aquaria.Regardless of population of origin,fish reared in turbid water were marginally less active and performed fewer social behaviors than those reared in clear water.On the other hand,when tested against a competitor in turbid water,males performed more aggressive behaviors,regardless of population of origin or rearing environment.Our results suggest a plastic behavioral response to turbidity that may allow P multicolor to persist over a range of turbidity levels in nature by decreasing activity and general social behaviors and intensifying reproductive behaviors to ensure reproductive success [ Current Zoology 58 (1):146-157,2012].

  16. Visualizing transplanted muscle flaps using minimally invasive multi-electrode bioimpedance spectroscopy

    Science.gov (United States)

    Gordon, R.; Zorkova, V.; Min, M.; Rätsep, I.

    2010-04-01

    We describe here an imaging system that uses bioimpedance spectroscopy with multi-electrode array to indicate the state of muscle flap regions under the array. The system is able to differentiate between different health states in the tissue and give early information about the location and size of ischemic sub-regions. The array will be 4*8 electrodes with the spacing of 5mm between the electrodes (the number of electrodes and the spacing may vary). The electrodes are minimally invasive short stainless steel needles, that penetrate 0.3 mm into the tissue with the goal of achieving a wet electric contact. We combine 32 configurations of 4-electrode multi-frequency impedance measurements to derive a health-state map for the transplanted flap. The imaging method is tested on a model consisting of 2 tissues and FEM software (Finite Element Method -COMSOL Multiphysics based) is used to conduct the measurements virtually. Dedicated multichannel bioimpedance measurement equipment has already been developed and tested, that cover the frequency range from 100 Hz to 1 MHz.

  17. Electrode structures and surfaces for Li batteries

    Energy Technology Data Exchange (ETDEWEB)

    Thackeray, Michael M.; Kang, Sun-Ho; Balasubramanian, Mahalingam; Croy, Jason

    2017-03-14

    This invention relates to methods of preparing positive electrode materials for electrochemical cells and batteries. It relates, in particular, to a method for fabricating lithium-metal-oxide electrode materials for lithium cells and batteries. The method comprises contacting a hydrogen-lithium-manganese-oxide material with one or more metal ions, preferably in an acidic solution, to insert the one or more metal ions into the hydrogen-lithium-manganese-oxide material; heat-treating the resulting product to form a powdered metal oxide composition; and forming an electrode from the powdered metal oxide composition.

  18. Conducting polymer electrodes for gel electrophoresis.

    Directory of Open Access Journals (Sweden)

    Katarina Bengtsson

    Full Text Available In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene (PEDOT can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  19. Fluctuations at Electrode-YSZ Interfaces

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Hansen, Karin Vels; Skou, Eivind

    of the damping by the large interface. Fig.\\,1 shows a slow potential sweep on a Pt point electrode on a YSZ surface. For the part of the anodic and the cathodic branches where the electrode approaches equilibrium, quadratic expressions are used as smooth approximations for the current -- overvoltage relation...... in D/A converters, duty cycles of thermo regulators, etc. But even so, the dramatic spikes seen at the Ni anode emphasizes the care that must be taken in order to obtain reproducible results from point electrode studies. However, it is noted that Pt cathodes and Ni anodes show reverse patterns...... property of the interface. \

  20. A method for making a nickel electrode

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, I.; Ikeyama, M.; Isikava, T.; Ivaki, T.; Yanashkhara, N.

    1983-07-14

    A powder of an active mass is applied to a foam metal plate and it is pressed into the pores of the base. The excess mass is removed from the surface, after which a grid structure is formed on this surface with heating of a powder of a thermally seating resin of the polyethylene type. Then, submerging the electrode plate into the resin suspension, the entire surface of the electrode is covered with a thin layer of powder of a fluorine bearing resin. The electrode has a long service life.