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Sample records for electrode force changeable

  1. Path planning in changeable environments

    NARCIS (Netherlands)

    Nieuwenhuisen, D.

    2007-01-01

    This thesis addresses path planning in changeable environments. In contrast to traditional path planning that deals with static environments, in changeable environments objects are allowed to change their configurations over time. In many cases, path planning algorithms must facilitate quick

  2. In situ electrochemical atomic force microscope study on graphite electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Hirasawa, K.A.; Sato, Tomohiro; Asahina, Hitoshi; Yamaguchi, Shoji; Mori, Shoichiro [Mitsubishi Chemical Corp., Inashiki, Ibaraki (Japan). Tsukuba Research Center

    1997-04-01

    Interest in the formation of the solid electrolyte interphase (SEI) film on graphite electrodes has increased recently in the quest to improve the performance of lithium-ion batteries. Topographic and frictional changes on the surface of a highly oriented pyrolytic graphite electrode in 1 M LiCiO{sub 4} ethylene carbonate/ethylmethyl carbonate (1:1) electrolyte were examined during charge and discharge by in situ electrochemical atomic force microscopy and friction force microscopy simultaneously in real-time. Solid electrolyte interphase film formation commenced at approximately 2 V vs. Li/Li{sup +} and stable film formation with an island-like morphology was observed below approximately 0.9 V vs. Li/Li{sup +}. Further experiments on a KS-44 graphite/polyvinylidene difluoride binder composite electrode showed similar phenomena.

  3. Attractive forces in microporous carbon electrodes for capacitive deionization

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Porada, S.; Levi, M.; Bazant, M.Z.

    2014-01-01

    The recently developed modified Donnan (mD) model provides a simple and useful description of the electrical double layer in microporous carbon electrodes, suitable for incorporation in porous electrode theory. By postulating an attractive excess chemical potential for each ion in the micropores

  4. The Changeable Block Distance System Analysis

    Science.gov (United States)

    Lewiński, Andrzej; Toruń, Andrzej

    The paper treats about efficiency analysis in Changeable Block Distance (CBD) System connected with wireless positioning and control of train. The analysis is based on modeling of typical ERTMS line and comparison with actual and future traffic. The calculations are related to assumed parameters of railway traffic corresponding to real time - table of distance Psary - Góra Włodowska from CMK line equipped in classic, ETCS Level 1 and ETCS with CBD systems.

  5. Insertion forces and intracochlear trauma in temporal bone specimens implanted with a straight atraumatic electrode array.

    Science.gov (United States)

    Mirsalehi, Marjan; Rau, Thomas S; Harbach, Lenka; Hügl, Silke; Mohebbi, Saleh; Lenarz, Thomas; Majdani, Omid

    2017-05-01

    The aim of the study was to evaluate insertion forces during manual insertion of a straight atraumatic electrode in human temporal bones, and post-implantation histologic evaluation of the samples to determine whether violation of intracochlear structures is related to insertion forces. In order to minimize intracochlear trauma and preserve residual hearing during cochlear implantation, knowledge of the insertion forces is necessary. Ten fresh frozen human temporal bones were prepared with canal wall down mastoidectomy. All samples were mounted on a one-axis force sensor. Insertion of a 16-mm straight atraumatic electrode was performed from different angles to induce "traumatic" insertion. Histologic evaluation was performed in order to evaluate intracochlear trauma. In 4 of 10 samples, dislocation of the electrode into scala vestibuli was observed. The mean insertion force for all 10 procedures was 0.003 ± 0.005 N. Insertion forces measured around the site of dislocation to scala vestibuli in 3 of 4 samples were significantly higher than insertion forces at the same location of the cochleae measured in samples without trauma (p straight atraumatic electrode is lower than reported by other studies using longer electrodes. Based on our study, insertion forces leading to basilar membrane trauma may be lower than the previously reported direct rupture forces.

  6. Competing forces in liquid metal electrodes and batteries

    Science.gov (United States)

    Ashour, Rakan F.; Kelley, Douglas H.; Salas, Alejandro; Starace, Marco; Weber, Norbert; Weier, Tom

    2018-02-01

    Liquid metal batteries are proposed for low-cost grid scale energy storage. During their operation, solid intermetallic phases often form in the cathode and are known to limit the capacity of the cell. Fluid flow in the liquid electrodes can enhance mass transfer and reduce the formation of localized intermetallics, and fluid flow can be promoted by careful choice of the locations and topology of a battery's electrical connections. In this context we study four phenomena that drive flow: Rayleigh-Bénard convection, internally heated convection, electro-vortex flow, and swirl flow, in both experiment and simulation. In experiments, we use ultrasound Doppler velocimetry (UDV) to measure the flow in a eutectic PbBi electrode at 160 °C and subject to all four phenomena. In numerical simulations, we isolate the phenomena and simulate each separately using OpenFOAM. Comparing simulated velocities to experiments via a UDV beam model, we find that all four phenomena can enhance mass transfer in LMBs. We explain the flow direction, describe how the phenomena interact, and propose dimensionless numbers for estimating their mutual relevance. A brief discussion of electrical connections summarizes the engineering implications of our work.

  7. Directives to support the design of changeable (I)PSS

    NARCIS (Netherlands)

    Pereira Pessoa, Marcus Vinicius; Jauregui Becker, Juan Manuel; Maier, Anja; Skec, Stanko; Kim, Harrison; Kokkolaras, Michael; Oehmen, Josef; Fadel, Georges; Salustri, Filippo; Van der Loos, Mike

    2017-01-01

    Product service models (PSM) benefits are not limited to its providers and costumers, but the whole society might also take advantage from its sustainability impact. Achieving these benefits, though, require changeable product service systems ((I)PSS). Changeability means the (I)PSS' modules have

  8. Particles with changeable topology in nematic colloids

    International Nuclear Information System (INIS)

    Ravnik, Miha; Čopar, Simon; Žumer, Slobodan

    2015-01-01

    We show that nematic colloids can serve as a highly variable and controllable platform for studying inclusions with changeable topology and their effects on the surrounding ordering fields. We explore morphing of toroidal and knotted colloidal particles into effective spheres, distinctively changing their Euler characteristic and affecting the surrounding nematic field, including topological defect structures. With toroidal particles, the inner nematic defect eventually transitions from a wide loop to a point defect (a small loop). Trefoil particles become linked with two knotted defect loops, mutually forming a three component link, that upon tightening transform into a two-component particle-defect loop link. For more detailed topological analysis, Pontryagin-Thom surfaces are calculated and visualised, indicating an interesting cascade of defect rewirings caused by the shape morphing of the knotted particles. (paper)

  9. A Fabrication Technique for Nano-gap Electrodes by Atomic Force Microscopy Nano lithography

    International Nuclear Information System (INIS)

    Jalal Rouhi; Shahrom Mahmud; Hutagalung, S.D.; Kakooei, S.

    2011-01-01

    A simple technique is introduced for fabrication of nano-gap electrodes by using nano-oxidation atomic force microscopy (AFM) lithography with a Cr/ Pt coated silicon tip. AFM local anodic oxidation was performed on silicon-on-insulator (SOI) surfaces by optimization of desired conditions to control process in contact mode. Silicon electrodes with gaps of sub 31 nm were fabricated by nano-oxidation method. This technique which is simple, controllable, inexpensive and fast is capable of fabricating nano-gap structures. The current-voltage measurements (I-V) of the electrodes demonstrated very good insulating characteristics. The results show that silicon electrodes have a great potential for fabrication of single molecule transistors (SMT), single electron transistors (SET) and the other nano electronic devices. (author)

  10. Double Layer of a Gold Electrode Probed by AFM Force Measurements

    NARCIS (Netherlands)

    Barten, D.; Kleijn, J.M.; Duval, J.F.L.; Leeuwen, van H.P.; Lyklema, J.; Cohen Stuart, M.A.

    2003-01-01

    Colloidal probe atomic force microscopy was used to determine the electric double layer interactions between a gold electrode and a spherical silica probe. The double layer properties of the gold/solution interface were varied through the pH and salt concentration of the electrolyte, as well as by

  11. Ethnicity in censuses: Changeable and inconstant category

    Directory of Open Access Journals (Sweden)

    Mrđen Snježana

    2002-01-01

    Full Text Available The issue of ethnicity was set in all censuses of SFRY, as well as in the first censuses in countries that were created after its disintegration. When analyzing the censuses it can be concluded that it is a changeable category. Not only was the manner of forming the question in censuses changing, but also the number of categories of nationality and their order in published census' results. It depended on state policy and the political situation preceding the censuses. Since the answer on the issues of ethnicity is a subjective criterion, and it was written down according to the freely declared statement of the residents, guaranteed by the Constitution. It has often happened that same individuals have declared themselves differently from one census to another, and also some categories of ethnicity have vanished and some others were created. Although in SFRY nations and ethnicities were equal, still indirectly in published results, existence of these two categories was indicated. But, in newly created countries, the manner of forming the question of ethnicity was changed, their number and order were also changed and the notion of 'minority' was again introduced, indicating, beyond doubt, a different status of nationality (except the majority from the one in the former Yugoslavia.

  12. Nanotribology at single crystal electrodes: Influence of ionic adsorbates on friction forces studied with AFM

    Energy Technology Data Exchange (ETDEWEB)

    Hausen, Florian; Nielinger, Michael; Ernst, Siegfried [Institut fuer Physikalische und Theoretische Chemie, Universitaet Bonn, Roemerstrasse 164, D-53117 Bonn (Germany); Baltruschat, Helmut [Institut fuer Physikalische und Theoretische Chemie, Universitaet Bonn, Roemerstrasse 164, D-53117 Bonn (Germany)], E-mail: baltruschat@uni-bonn.de

    2008-09-01

    We present friction force measurements on Au(1 1 1) single crystal electrode surfaces performed under electrochemical conditions using an atomic force microscope (AFM). At monoatomic steps friction is increased in both scan directions. In 0.05 M sulfuric acid an increase of friction is observed with the increase of adsorbed sulfate. Friction force increases non-linearly with load. Cu UPD also increases friction in presence of sulfate. However, in presence of 4 x 10{sup -4} M chloride friction is much smaller for all deposited Cu coverages - ranging from a submonolayer up to bulk copper compared to the solution without chloride. After dissolution of bulk copper clusters deposited on Au(1 1 1) we observed an area with higher friction forces due to the formation of an alloy between gold and copper.

  13. Approaching Environmental Sustainability: Perceptions of Self-Efficacy and Changeability.

    Science.gov (United States)

    Schutte, Nicola S; Bhullar, Navjot

    2017-04-03

    This paper describes a model focused on the role of self-efficacy and belief in changeability of behavior in motivating environmentally sustainable behavior. The model was tested in two studies. The first study found that participants who had greater self-efficacy for sustainability behavior and a greater belief in their changeability of sustainability behavior had a higher level of approach motivation toward sustainability behavior and reported more such actual behavior. The second study investigated the effect of brief interventions intended to increase perception of self-efficacy for sustainability-related purchasing and changeability of sustainability-related purchasing. The intervention that focused on enhancing self-efficacy for making sustainability-related purchases had the strongest impact on intention to purchase. These findings have implications for interventions intended to change behavior related to environmental sustainability.

  14. The Researches on Cycle-Changeable Generation Settlement Method

    Science.gov (United States)

    XU, Jun; LONG, Suyan; LV, Jianhu

    2018-03-01

    Through the analysis of the business characteristics and problems of price adjustment, a cycle-changeable generation settlement method is proposed to support any time cycle settlement, and put forward a complete set of solutions, including the creation of settlement tasks, time power dismantle, generating fixed cycle of electricity, net energy split. At the same time, the overall design flow of cycle-changeable settlement is given. This method supports multiple price adjustments during the month, and also is an effective solution to the cost reduction of month-after price adjustment.

  15. The influence of Lampblack on capacity retention in Pb/PbSO/sub 4/ electrodes with forced flow of electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Borger, W.; Hullmeine, U.

    1984-10-01

    High active material utilization of Pb/PbSO/sub 4/ electrodes after formation in the range of 170 - 120 Ah/kg is obtained when these electrodes are discharged at 50-200 A/kg current density with forced flow of electrolyte. Decline of capacity was observed on further cycling at high current density and forced flow of electrolyte. The extent of capacity decline in these electrodes is largely influenced by the amount of additives in the active material, e.g. lampblack and expander.

  16. Wall Climbing Robot Using Electrostatic Adhesion Force Generated by Flexible Interdigital Electrodes

    Directory of Open Access Journals (Sweden)

    Rong Liu

    2013-01-01

    Full Text Available Electrostatic adhesion technology has broad application prospects on wall climbing robots because of its unique characteristics compared with other types of adhesion technologies. A double tracked wall climbing robot based on electrostatic adhesion technology is presented including electrode panel design, mechanical structure design, power supply system design and control system design. A theoretical adhesion model was established and the electrostatic potential and field were expressed by series expansions in terms of solutions of the Laplace function. Based on this model, the electrostatic adhesion force was calculated using the Maxwell stress tensor formulation. Several important factors which may influence the electrostatic adhesion force were analysed and discussed by both FEM simulation and theoretical calculation. In addition, experiments on the adhesion performance of the electrode panel and the climbing performance of the robot on various wall materials were carried out. Both the simulation and experiment results verify the feasibility of electrostatic adhesion technology being applied on wall climbing robots. The theoretical model and calculation method for the electrostatic adhesion force proposed in this paper are also justified.

  17. Potential dependent adhesion forces on bare and underpotential deposition modified electrode surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Serafin, J.M.; Hsieh, S.J.; Monahan, J.; Gewirth, A.A. [Univ. of Illinois, Urbana, IL (United States)

    1998-12-03

    Adhesion force measurements are used to determine the potential dependence of the force of adhesion between a Si{sub 3}N{sub 4} cantilever and a Au(111) surface modified by the underpotential deposition (upd) of Bi or Cu in acid solution or by oxide formation. The measured work of adhesion is near zero for most of the potential region examined in Bi upd but rises after the formation of a full Bi monolayer. The work of adhesion is high at positive potentials for Cu upd but then decreases as the Cu partial and full monolayers are formed. The work of adhesion is low in the oxide region on Au(111) but rises following the sulfate disordering transition at 1.1 V vs NHE. These results are interpreted in terms of the degree of solvent order on the electrode surface.

  18. A curved electrode electrostatic actuator designed for large displacement and force in an underwater environment

    International Nuclear Information System (INIS)

    Preetham, B S; Lake, Melinda A; Hoelzle, David J

    2017-01-01

    There is a need for the development of large displacement ( O (10 −6 ) m) and force ( O (10 −6 ) N) electrostatic actuators with low actuation voltages (<  ±8 V) for underwater bio- MEMS applications. In this paper, we present the design, fabrication, and characterization of a curved electrode electrostatic actuator in a clamped–clamped beam configuration meant to operate in an underwater environment. Our curved electrode actuator is unique in that it operates in a stable manner past the pull-in instability. Models based on the Rayleigh–Ritz method accurately predict the onset of static instability and the displacement versus voltage function, as validated by quasistatic experiments. We demonstrate that the actuator is capable of achieving a large peak-to-peak displacement of 19.5 µ m and force of 43 µ N for a low actuation voltage of less than  ±8 V and is thus appropriate for underwater bio -MEMS applications. (paper)

  19. Electrochemical characterization of tenoxicam using a bare carbon paste electrode under stagnant and forced convection conditions

    International Nuclear Information System (INIS)

    Guzmán-Hernández, D.S.; Ramírez-Silva, M.T.; Palomar-Pardavé, M.; Corona-Avendaño, S.; Galano, Annia; Rojas-Hernández, A.; Romero-Romo, M.

    2012-01-01

    Highlights: ► Tenoxicam electrochemical oxidation was studied from aqueous solution with a CPE. ► Both stagnant and forced convection conditions were considered. ► We found tenoxicam electrochemical oxidation is a mass transfer-controlled process. ► An EC mechanism was found where the electrodic and chemical kinetics are fast. ► It was found that in this case n = 2 and E 1/2 = 0.770 V. ► Calculated D was 4.09 × 10 −6 cm 2 s −1 which compares with theoretically estimated. - Abstract: From potentiostatic current transients and voltammetry studies, carried out under both stagnant and forced convection conditions, the tenoxicam electrochemical behavior on a bare carbon paste rotating disk electrode was assessed in an aqueous solution (pH = 0.403). It was found that tenoxicam's electrochemical oxidation is a mass transfer-controlled process where a current peak is clearly formed at around 0.74 V when the potential scan was varied in the positive direction. However, when the potential was switched to the negative direction, up to the initial potential value, no reduction peak was formed. Tenoxicam's electrochemical oxidation follows an EC mechanism where the electrodic and chemical kinetics are fast. From sample-current voltammetry both the number of electrons, n, that tenoxicam losses during its electro-oxidation and its half-wave potential, E 1/2 , were determined to be 2 and 0.770 V vs. Ag/AgCl, respectively. Moreover, from differential pulse voltammetry plots it was confirmed that effectively in this case n = 2. Considering 2 electrons and both the Randles-Sevcik and Cotrell equations, the tenoxicam's diffusion coefficient, D, was determined to be (3.745 ± 0.077) × 10 −6 and (4.116 ± 0.086) × 10 −6 cm 2 s −1 , respectively. From linear sweep voltammetry plots recorded under forced convection conditions, it was found that Levich's equation describes adequately the limiting current recorded as a function of the electrode rotation rate, from

  20. Placement Design of Changeable Message Signs on Curved Roadways

    Directory of Open Access Journals (Sweden)

    Zhongren Wang, Ph.D. P.E. T.E.

    2015-01-01

    Full Text Available This paper presented a fundamental framework for Changeable Message Sign (CMS placement design along roadways with horizontal curves. This analytical framework determines the available distance for motorists to read and react to CMS messages based on CMS character height, driver's cone of vision, CMS pixel's cone of legibility, roadway horizontal curve radius, and CMS lateral and vertical placement. Sample design charts were developed to illustrate how the analytical framework may facilitate CMS placement design.

  1. Situational Script Management of Business Processes with Changeable Structure

    OpenAIRE

    Chaliy, Sergey; Chala, Oksana

    2008-01-01

    In the presented work the problem of management business-processes with changeable structure is considered and situational based approach to its decision is offered. The approach is based on situational model of management business-process according to which process is represented as a set of situations. The script defining necessary actions is connected with each situation. Management of process is carried out by means of the rules formalizing functional requirements to processes.

  2. Novel Threshold Changeable Secret Sharing Schemes Based on Polynomial Interpolation.

    Science.gov (United States)

    Yuan, Lifeng; Li, Mingchu; Guo, Cheng; Choo, Kim-Kwang Raymond; Ren, Yizhi

    2016-01-01

    After any distribution of secret sharing shadows in a threshold changeable secret sharing scheme, the threshold may need to be adjusted to deal with changes in the security policy and adversary structure. For example, when employees leave the organization, it is not realistic to expect departing employees to ensure the security of their secret shadows. Therefore, in 2012, Zhang et al. proposed (t → t', n) and ({t1, t2,⋯, tN}, n) threshold changeable secret sharing schemes. However, their schemes suffer from a number of limitations such as strict limit on the threshold values, large storage space requirement for secret shadows, and significant computation for constructing and recovering polynomials. To address these limitations, we propose two improved dealer-free threshold changeable secret sharing schemes. In our schemes, we construct polynomials to update secret shadows, and use two-variable one-way function to resist collusion attacks and secure the information stored by the combiner. We then demonstrate our schemes can adjust the threshold safely.

  3. Large-Area Cross-Aligned Silver Nanowire Electrodes for Flexible, Transparent, and Force-Sensitive Mechanochromic Touch Screens.

    Science.gov (United States)

    Cho, Seungse; Kang, Saewon; Pandya, Ashish; Shanker, Ravi; Khan, Ziyauddin; Lee, Youngsu; Park, Jonghwa; Craig, Stephen L; Ko, Hyunhyub

    2017-04-25

    Silver nanowire (AgNW) networks are considered to be promising structures for use as flexible transparent electrodes for various optoelectronic devices. One important application of AgNW transparent electrodes is the flexible touch screens. However, the performances of flexible touch screens are still limited by the large surface roughness and low electrical to optical conductivity ratio of random network AgNW electrodes. In addition, although the perception of writing force on the touch screen enables a variety of different functions, the current technology still relies on the complicated capacitive force touch sensors. This paper demonstrates a simple and high-throughput bar-coating assembly technique for the fabrication of large-area (>20 × 20 cm 2 ), highly cross-aligned AgNW networks for transparent electrodes with the sheet resistance of 21.0 Ω sq -1 at 95.0% of optical transmittance, which compares favorably with that of random AgNW networks (sheet resistance of 21.0 Ω sq -1 at 90.4% of optical transmittance). As a proof of concept demonstration, we fabricate flexible, transparent, and force-sensitive touch screens using cross-aligned AgNW electrodes integrated with mechanochromic spiropyran-polydimethylsiloxane composite film. Our force-sensitive touch screens enable the precise monitoring of dynamic writings, tracing and drawing of underneath pictures, and perception of handwriting patterns with locally different writing forces. The suggested technique provides a robust and powerful platform for the controllable assembly of nanowires beyond the scale of conventional fabrication techniques, which can find diverse applications in multifunctional flexible electronic and optoelectronic devices.

  4. Electric field and dielectrophoretic force on a dielectric particle chain in a parallel-plate electrode system

    International Nuclear Information System (INIS)

    Techaumnat, B; Eua-arporn, B; Takuma, T

    2004-01-01

    This paper presents results of calculations of the electric field and dielectrophoretic force on a dielectric particle chain suspended in a host liquid lying between parallel-plate electrodes. The method of calculation is based on the method of multipole images using the multipole re-expansion technique. We have investigated the effect of the particle permittivity, the tilt angle (between the chain and the applied field) and the chain arrangement on the electric field and force. The results show that the electric field intensification rises in accordance with the increase in the ratio of the particle-to-liquid permittivity, Γ ε . The electric field at the contact point between the particles decreases with increasing tilt angle, while the maximal field at the contact point between the particles and the plate electrodes is almost unchanged. The maximal field can be approximated by a simple formula, which is a quadratic function of Γ ε . The dielectrophoretic force depends significantly on the distance from other particles or an electrode. However, for the tilt angles in this paper, the horizontal force on the upper particle of the chain always has the direction opposite to the shear direction. The maximal horizontal force of a chain varies proportional to (Γ ε - 1) 1.7 if the particles in the chain are still in contact with each other. The approximated force, based on the force on an isolated chain, has been compared with our calculation results. The comparison shows that no approximation model agrees well with our results throughout the range of permittivity ratios

  5. The Development and Preliminary Validation of the Behavior, Environment, and Changeability Survey (BECS)

    Science.gov (United States)

    Walsh, Jennifer R.; Hebert, Angel; Byrd-Bredbenner, Carol; Carey, Gale; Colby, Sarah; Brown-Esters, Onikia N.; Greene, Geoffrey; Hoerr, Sharon; Horacek, Tanya; Kattelmann, Kendra; Kidd, Tandalayo; Koenings, Mallory; Phillips, Beatrice; Shelnutt, Karla P.; White, Adrienne A.

    2012-01-01

    Objective: To develop and test the validity of the Behavior, Environment, and Changeability Survey (BECS) for identifying the importance and changeability of nutrition, exercise, and stress management behavior and related aspects of the environment. Design: A cross-sectional, online survey of the BECS and selected validated instruments. Setting:…

  6. Changeability of consumer preferences concerning the methods of fruit production

    Directory of Open Access Journals (Sweden)

    Eugenia Czernyszewicz

    2009-01-01

    Full Text Available The purpose of the paper was to establish and compare consumer preferences concerning the methods of fruit production (traditional or organic ones in the years 2001, 2003 and 2006 and the relations between the preferences and the socio-economic and demographic features of the consumers. The analysis was conducted on the basis of the data from surveys carried out among the inhabitants of Lublin. Results of those surveys point out that certain features of the consumers such as the sex, incomes and the family type significantly differentiated preferences concerning the method of fruit production. Increased incomes were connected with greater acceptance of the organic method, and their decrease was related to greater frequency of indicating the conventional method. Interest in the method of production, while buying the fruit was significantly higher among men than among women. Declaring the willingness to pay more for organic fruit was also correlated with the consumers’ sex. Besides, in 2006 it was not too strongly related to the incomes of the respondents. In the years 2001 and 2006 changeability of preferences con-cerning the willingness to pay a higher price for organic fruit and no change in the interest in the technology of fruit production while purchasing the fruit were shown.

  7. Comparative morphology of changeable skin papillae in octopus and cuttlefish.

    Science.gov (United States)

    Allen, Justine J; Bell, George R R; Kuzirian, Alan M; Velankar, Sachin S; Hanlon, Roger T

    2014-04-01

    A major component of cephalopod adaptive camouflage behavior has rarely been studied: their ability to change the three-dimensionality of their skin by morphing their malleable dermal papillae. Recent work has established that simple, conical papillae in cuttlefish (Sepia officinalis) function as muscular hydrostats; that is, the muscles that extend a papilla also provide its structural support. We used brightfield and scanning electron microscopy to investigate and compare the functional morphology of nine types of papillae of different shapes, sizes and complexity in six species: S. officinalis small dorsal papillae, Octopus vulgaris small dorsal and ventral eye papillae, Macrotritopus defilippi dorsal eye papillae, Abdopus aculeatus major mantle papillae, O. bimaculoides arm, minor mantle, and dorsal eye papillae, and S. apama face ridge papillae. Most papillae have two sets of muscles responsible for extension: circular dermal erector muscles arranged in a concentric pattern to lift the papilla away from the body surface and horizontal dermal erector muscles to pull the papilla's perimeter toward its core and determine shape. A third set of muscles, retractors, appears to be responsible for pulling a papilla's apex down toward the body surface while stretching out its base. Connective tissue infiltrated with mucopolysaccharides assists with structural support. S. apama face ridge papillae are different: the contraction of erector muscles perpendicular to the ridge causes overlying tissues to buckle. In this case, mucopolysaccharide-rich connective tissue provides structural support. These six species possess changeable papillae that are diverse in size and shape, yet with one exception they share somewhat similar functional morphologies. Future research on papilla morphology, biomechanics and neural control in the many unexamined species of octopus and cuttlefish may uncover new principles of actuation in soft, flexible tissue.

  8. Nanoscale current spreading analysis in solution-processed graphene oxide/silver nanowire transparent electrodes via conductive atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Joseph E.; Perumal, Ajay; Bradley, Donal D. C.; Stavrinou, Paul N.; Anthopoulos, Thomas D., E-mail: t.anthopoulos@ic.ac.uk [Department of Physics and Centre for Plastic Electronics, Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom)

    2016-05-21

    We use conductive atomic force microscopy (CAFM) to study the origin of long-range conductivity in model transparent conductive electrodes composed of networks of reduced graphene oxide (rGO{sub X}) and silver nanowires (AgNWs), with nanoscale spatial resolution. Pristine networks of rGO{sub X} (1–3 monolayers-thick) and AgNWs exhibit sheet resistances of ∼100–1000 kΩ/□ and 100–900 Ω/□, respectively. When the materials are deposited sequentially to form bilayer rGO{sub X}/AgNW electrodes and thermally annealed at 200 °C, the sheet resistance reduces by up to 36% as compared to pristine AgNW networks. CAFM was used to analyze the current spreading in both systems in order to identify the nanoscale phenomena responsible for this effect. For rGO{sub X} networks, the low intra-flake conductivity and the inter-flake contact resistance is found to dominate the macroscopic sheet resistance, while for AgNW networks the latter is determined by the density of the inter-AgNW junctions and their associated resistance. In the case of the bilayer rGO{sub X}/AgNWs' networks, rGO{sub X} flakes are found to form conductive “bridges” between AgNWs. We show that these additional nanoscopic electrical connections are responsible for the enhanced macroscopic conductivity of the bilayer rGO{sub X}/AgNW electrodes. Finally, the critical role of thermal annealing on the formation of these nanoscopic connections is discussed.

  9. Capacity of textile filters for wastewater Treatment at changeable wastewater level – a hydraulic model

    Directory of Open Access Journals (Sweden)

    Marcin Spychała

    2016-12-01

    Full Text Available The aim of the study was to describe in a mathematical manner the hydraulic capacity of textile filters for wastewater treatment at changeable wastewater levels during a period between consecutive doses, taking into consideration the decisive factors for flow-conditions of filtering media. Highly changeable and slightly changeable flow-conditions tests were performed on reactors equipped with non-woven geo-textile filters. Hydraulic conductivity of filter material coupons was determined. The dry mass covering the surface and contained in internal space of filtering material was then indicated and a mathematical model was elaborated. Flow characteristics during the highly changeable flow-condition test were sensitivity to differentiated values of hydraulic conductivity in horizontal zones of filtering layer. During the slightly changeable flow-conditions experiment the differences in permeability and hydraulic conductivity of different filter (horizontal zones height regions were much smaller. The proposed modelling approach in spite of its simplicity provides a satisfactory agreement with empirical data and therefore enables to simulate the hydraulic capacity of vertically oriented textile filters. The mathematical model reflects the significant impact of the filter characteristics (textile permeability at different filter height and operational conditions (dosing frequency on the textile filters hydraulic capacity.

  10. Cantilever-type electrode array-based high-throughput microparticle sorting platform driven by gravitation and negative dielectrophoretic force

    International Nuclear Information System (INIS)

    Kim, Youngho; Kim, Byungkyu; Lee, Junghun; Kim, Younggeun; Shin, Sang-Mo

    2011-01-01

    In this paper, we describe a cantilever-type electrode (CE) array-based high-throughput sorting platform, which is a tool used to separate microparticles using gravitation and negative dielectrophoretic (n-DEP) force. This platform consists of meso-size channels and a CE array, which is designed to separate a large number of target particles by differences in their dielectric material properties (DMP) and the weight of the particles. We employ a two-step separation process, with sedimentation as the first step and n-DEP as the second step. In order to differentiate the weight and the DMP of each particle, we employ the sedimentation phenomena in a vertical channel and the CE-based n-DEP in an inclined channel. By using three kinds of polystyrene beads with diameters of 10, 25 and 50 µm, the optimal population (10 7 beads ml −1 ) of particles and the appropriate length (25 mm) of the vertical channel for high performance were determined experimentally. Conclusively, by combining sedimentation and n-DEP schemes, we achieve 74.5, 94.7 and 100% separation efficiency for sorting microparticles with a diameter of 10, 25 and 50 µm, respectively.

  11. Glocalized Manufacturing – Local Supply Chains on a Global Scale and Changeable Technologies

    DEFF Research Database (Denmark)

    Hadar, Ronen; Bilberg, Arne

    , and customization towards customers and consumers, even at the expense of current competitive advantages such as price reduction. The paper examines the opportunities and advantages in setting up a network of glocalized self-sufficient supply chains around an intelligent changeable production facility. In contrast...

  12. 5th International Conference on Changeable, Agile, Reconfigurable and Virtual Production

    CERN Document Server

    2014-01-01

    The changing manufacturing environment requires more responsive and adaptable manufacturing systems. The theme of the 5th International Conference on Changeable, Agile, Reconfigurable and Virtual production (CARV2013) is "Enabling Manufacturing Competitiveness and Economic Sustainability. Leading edge research and best implementation practices and experiences, which address these important issues and challenges, are presented. The proceedings include advances in manufacturing systems design, planning, evaluation, control and evolving paradigms such as mass customization, personalization, changeability, re-configurability and flexibility. New and important concepts such as the dynamic product families and platforms, co-evolution of products and systems, and methods for enhancing manufacturing systems' economic sustainability and prolonging their life to produce more than one product generation are treated. Enablers of change in manufacturing systems, production volume and capability, scalability and managing t...

  13. One-way Hash function construction based on the chaotic map with changeable-parameter

    International Nuclear Information System (INIS)

    Xiao Di; Liao Xiaofeng; Deng Shaojiang

    2005-01-01

    An algorithm for one-way Hash function construction based on the chaotic map with changeable-parameter is proposed in this paper. A piecewise linear chaotic map with changeable-parameter P is chosen, and cipher block chaining mode (CBC) is introduced to ensure that the parameter P in each iteration is dynamically decided by the last-time iteration value and the corresponding message bit in different positions. The final Hash value is obtained by means of the linear transform on the iteration sequence. Theoretical analysis and computer simulation indicate that our algorithm can satisfy all the performance requirements of Hash function in an efficient and flexible manner. It is practicable and reliable, with high potential to be adopted for E-commerce

  14. One-way Hash function construction based on the chaotic map with changeable-parameter

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Di [College of Computer Science and Engineering, Chongqing University, Chongqing 400044 (China) and College of Mechanical Engineering, Chongqing University, Chongqing 400044 (China)]. E-mail: xiaodi_cqu@hotmail.com; Liao Xiaofeng [College of Computer Science and Engineering, Chongqing University, Chongqing 400044 (China)]. E-mail: xfliao@cqu.edu.cn; Deng Shaojiang [College of Computer Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2005-04-01

    An algorithm for one-way Hash function construction based on the chaotic map with changeable-parameter is proposed in this paper. A piecewise linear chaotic map with changeable-parameter P is chosen, and cipher block chaining mode (CBC) is introduced to ensure that the parameter P in each iteration is dynamically decided by the last-time iteration value and the corresponding message bit in different positions. The final Hash value is obtained by means of the linear transform on the iteration sequence. Theoretical analysis and computer simulation indicate that our algorithm can satisfy all the performance requirements of Hash function in an efficient and flexible manner. It is practicable and reliable, with high potential to be adopted for E-commerce.

  15. Food Neophobia in Wild Rats (Rattus norvegicus Inhabiting a Changeable Environment-A Field Study.

    Directory of Open Access Journals (Sweden)

    Klaudia Modlinska

    Full Text Available Food neophobia is a reaction to novel food observed in many animal species, particularly omnivores, including Rattus norvegicus. A neophobic reaction is typically characterised by avoidance of novel food and the necessity to assess both its potential value and toxicity by the animal. It has been hypothesised that this reaction is not observed in rats inhabiting a changeable environment with a high level of variability with regard to food and food sources. This study was conducted in such changeable conditions and it aims to demonstrate the behaviour of wild rats R. norvegicus in their natural habitat. The rats were studied in a farm setting, and the experimental arena was demarcated by a specially constructed pen which was freely accessible to the rats. At regular intervals, the rats were given new flavour- and smell-altered foods, while their behaviour was video-recorded. The results obtained in the study seem to confirm the hypothesis that rats inhabiting a highly changeable environment do not exhibit food neophobia. The observed reaction to novel food may be connected with a reaction to a novel object to a larger extent than to food neophobia. The value of the results obtained lies primarily in the fact that the study was conducted in the animals' natural habitat, and that it investigated their spontaneous behaviours.

  16. Assessment of masticatory performance by means of a color-changeable chewing gum.

    Science.gov (United States)

    Tarkowska, Agnieszka; Katzer, Lukasz; Ahlers, Marcus Oliver

    2017-01-01

    Previous research determined the relevance of masticatory performance with regard to nutritional status, cognitive functions, or stress management. In addition, the measurement of masticatory efficiency contributes to the evaluation of therapeutic successes within the stomatognathic system. However, the question remains unanswered as to what extent modern techniques are able to reproduce the subtle differences in masticatory efficiency within various patient groups. The purpose of this review is to provide an extensive summary of the evaluation of masticatory performance by means of a color-changeable chewing gum with regard to its clinical relevance and applicability. A general overview describing the various methods available for this task has already been published. This review focuses in depth on the research findings available on the technique of measuring masticatory performance by means of color-changeable chewing gum. Described are the mechanism and the differentiability of the color change and methods to evaluate the color changes. Subsequently, research on masticatory performance is conducted with regard to patient age groups, the impact of general diseases and the effect of prosthetic and surgical treatment. The studies indicate that color-changeable chewing gum is a valid and reliable method for the evaluation of masticatory function. Apart from other methods, in clinical practice this technique can enhance dental diagnostics as well as the assessment of therapy outcomes. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  17. Reactivity at the film/solution interface of ex situ prepared bismuth film electrodes: A scanning electrochemical microscopy (SECM) and atomic force microscopy (AFM) investigation

    International Nuclear Information System (INIS)

    Hocevar, Samo B.; Daniele, Salvatore; Bragato, Carlo; Ogorevc, Bozidar

    2007-01-01

    Bismuth film electrodes (BiFEs) prepared ex situ with and without complexing bromide ions in the modification solution were investigated using scanning electrochemical microscopy (SECM) and atomic force microscopy (AFM). A feedback mode of the SECM was employed to examine the conductivity and reactivity of a series of thin bismuth films deposited onto disk glassy carbon substrate electrodes (GCEs) of 3 mm in diameter. A platinum micro-electrode (φ = 25 μm) was used as the SECM tip, and current against tip/substrate distance was recorded in solutions containing either Ru(NH 3 ) 6 3+ or Fe(CN) 6 4- species as redox mediators. With both redox mediators positive feedback approach curves were recorded, which indicated that the bismuth film deposition protocol associated with the addition of bromide ions in the modification solution did not compromise the conductivity of the bismuth film in comparison with that prepared without bromide. However, at the former Bi film a slight kinetic hindering was observed in recycling Ru(NH 3 ) 6 3+ , suggesting a different surface potential. On the other hand, the approach curves recorded by using Fe(CN) 6 4- showed that both types of the aforementioned bismuth films exhibited local reactivity with the oxidised form of the redox mediator, and that bismuth film obtained with bromide ions exhibited slightly lower reactivity. The use of SECM in the scanning operation mode allowed us to ascertain that the bismuth deposits were uniformly distributed across the whole surface of the glassy carbon substrate electrode. Comparative AFM measurements corroborated the above findings and additionally revealed a denser growth of smaller bismuth crystals over the surface of the substrate electrode in the presence of bromide ions, while the crystals were bigger but sparser in the absence of bromide ions in the modification solution

  18. Properties of a color-changeable chewing gum used to evaluate masticatory performance.

    Science.gov (United States)

    Hama, Yohei; Kanazawa, Manabu; Minakuchi, Shunsuke; Uchida, Tatsuro; Sasaki, Yoshiyuki

    2014-04-01

    To clarify the basic properties of a color-changeable chewing gum to determine its applicability to evaluations of masticatory performance under different types of dental status. Ten participants with natural dentition aged 26-30 years chewed gum that changes color during several chewing strokes over five repetitions. Changes in color were assessed using a colorimeter, and then L*, a*, and b* values in the CIELAB color system were quantified. Relationships between chewing progression and color changes were assessed using regression analysis and the reliability of color changes was assessed using intraclass correlation coefficients. We then measured 42 dentate participants (age, 22-31 years) and 47 complete denture wearers (age, 44-90 years) to determine the detectability of masticatory performance under two types of dental status. Regression between the number of chewing strokes and the difference between two colors was non-linear. The intraclass correlation coefficients were highest between 60 and 160 chewing strokes. Dentate and edentulous groups significantly differed (Wilcoxon rank sum test) and values were widely distributed within each group. The color of the chewing gum changed over a wide range, which was sufficient to evaluate the masticatory performance of individuals with natural dentition and those with complete dentures. Changes in the color values of the gum reliably reflected masticatory performance. These findings indicate that the color-changeable chewing gum will be useful for evaluating masticatory performance under any dental status. Copyright © 2014 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  19. Association between masticatory performance using a colour-changeable chewing gum and jaw movement.

    Science.gov (United States)

    Komagamine, Y; Kanazawa, M; Minakuchi, S; Uchida, T; Sasaki, Y

    2011-08-01

    The purpose of this study was to investigate the relationship between masticatory performance as determined using a colour-changeable chewing gum and mandibular movements. Subjects comprised 45 fully dentate adults (23 men, 22 women; mean age, 28·1 years). The gum was chewed for a specified number of chewing strokes (20, 40, 60, 80, 120 or 160 strokes) without any instructions as to chewing side. A colourimeter was used to measure L*, a* and b* values (CIE-L*a*b* colour system) for the chewed gum, then the difference between two colours in the CIE-L*a*b* colour space (ΔE) for each number of chewing strokes was calculated according to a formula. Index of masticatory performance (ΔE60) for each subject was obtained using ΔE for 20, 40, 60, 80, 120 and 160 strokes. Mandibular movements were recorded using an opto-electric system with six degrees of freedom. Twelve parameters of mandibular movements relating to amplitude, duration, velocity and angle were computed for each cycle, and mean values for 10 cycles (from cycle 11 to 20) were calculated separately. Stepwise multiple regression analysis identified maximum closing velocity and closing angle as predictors accounting for 18% of the variation in ΔE60. These results suggest that lower angles of approach to intercuspation and faster speed during closing duration are associated with colour changes in the colour-changeable chewing gum. © 2011 Blackwell Publishing Ltd.

  20. Boron-doped Diamond Electrodes: Electrochemical, Atomic Force Microscopy and Raman Study towards Corrosion-modifications at Nanoscale

    International Nuclear Information System (INIS)

    Kavan, Ladislav; Vlckova Zivcova, Zuzana; Petrak, Vaclav; Frank, Otakar; Janda, Pavel; Tarabkova, Hana; Nesladek, Milos; Mortet, Vincent

    2015-01-01

    Highlights: • B-doped diamond is nanostructured by corrosion-driven modifications occurring at carbonaceous impurity sites (sp 2 -carbons). • The electrochemical oxidation partly transforms a hydrogen-terminated diamond surface to O-terminated one, but the electrocatalytic activity of plasmatically O-terminated diamond is not achieved. • In contrast to all usual sp 2 carbons, the Raman spectra of B-doped diamond electrodes do not change upon electrochemical charging/discharging. - Abstract: Comparative studies of boron-doped diamonds electrodes (polycrystalline, single-crystalline, H-/O-terminated, and with different sp 3 /sp 2 ratios) indicate morphological modifications of diamond which are initiated by corrosion at nanoscale. In-situ electrochemical AFM imaging evidences that the textural changes start at non-diamond carbonaceous impurity sites treated at high positive potentials (>2.2 V vs. Ag/AgCl). The primary perturbations subsequently develop into sub-micron-sized craters. Raman spectroscopy shows that the primary erosion site is graphite-like (sp 2 -carbon), which is preferentially removed by anodic oxidation. Other non-diamond impurity, viz. tetrahedral amorphous carbon (t-aC), is less sensitive to oxidative decomposition. The diamond-related Raman features, including the B-doping-assigned modes, are intact during reversible electrochemical charging/discharging, which is a salient difference from all usual sp 2 -carbons. The electrochemical oxidation partly transforms a hydrogen-terminated diamond surface to O-terminated one, but the electrocatalytic activity of plasmatically O-terminated diamond is not achieved for a model redox couple, Fe 3+/2+ . Electrochemical impedance spectra were fitted to six different equivalent circuits. The determination of acceptor concentrations is feasible even for highly-doped diamond electrodes.

  1. Boron-doped Diamond Electrodes: Electrochemical, Atomic Force Microscopy and Raman Study towards Corrosion-modifications at Nanoscale

    Czech Academy of Sciences Publication Activity Database

    Kavan, Ladislav; Vlčková Živcová, Zuzana; Petrák, Václav; Frank, Otakar; Janda, Pavel; Tarábková, Hana; Nesladek, M.; Mortet, Vincent

    2015-01-01

    Roč. 179, OCT 2015 (2015), s. 626-636 ISSN 0013-4686 R&D Projects: GA ČR GA13-31783S Institutional support: RVO:61388955 ; RVO:68378271 Keywords : Raman spectroelectrochemistry * atomic force microscopy * boron doped diamond Subject RIV: CG - Electrochemistry Impact factor: 4.803, year: 2015

  2. Drug Release from Phase-Changeable Nanodroplets Triggered by Low-Intensity Focused Ultrasound

    Science.gov (United States)

    Cao, Yang; Chen, Yuli; Yu, Tao; Guo, Yuan; Liu, Fengqiu; Yao, Yuanzhi; Li, Pan; Wang, Dong; Wang, Zhigang; Chen, Yu; Ran, Haitao

    2018-01-01

    Background: As one of the most effective triggers with high tissue-penetrating capability and non-invasive feature, ultrasound shows great potential for controlling the drug release and enhancing the chemotherapeutic efficacy. In this study, we report, for the first time, construction of a phase-changeable drug-delivery nanosystem with programmable low-intensity focused ultrasound (LIFU) that could trigger drug-release and significantly enhance anticancer drug delivery. Methods: Liquid-gas phase-changeable perfluorocarbon (perfluoropentane) and an anticancer drug (doxorubicin) were simultaneously encapsulated in two kinds of nanodroplets. By triggering LIFU, the nanodroplets could be converted into microbubbles locally in tumor tissues for acoustic imaging and the loaded anticancer drug (doxorubicin) was released after the microbubble collapse. Based on the acoustic property of shell materials, such as shell stiffness, two types of nanodroplets (lipid-based nanodroplets and PLGA-based nanodroplets) were activated by different acoustic pressure levels. Ultrasound irradiation duration and power of LIFU were tested and selected to monitor and control the drug release from nanodroplets. Various ultrasound energies were introduced to induce the phase transition and microbubble collapse of nanodroplets in vitro (3 W/3 min for lipid nanodroplets; 8 W/3 min for PLGA nanodroplets). Results: We detected three steps in the drug-releasing profiles exhibiting the programmable patterns. Importantly, the intratumoral accumulation and distribution of the drug with LIFU exposure were significantly enhanced, and tumor proliferation was substantially inhibited. Co-delivery of two drug-loaded nanodroplets could overcome the physical barriers of tumor tissues during chemotherapy. Conclusion: Our study provides a new strategy for the efficient ultrasound-triggered chemotherapy by nanocarriers with programmable LIFU capable of achieving the on-demand drug release. PMID:29507623

  3. Evaluation of TEG(®) and RoTEM(®) inter-changeability in trauma patients.

    Science.gov (United States)

    Hagemo, Jostein S; Næss, Paal A; Johansson, Pär; Windeløv, Nis A; Cohen, Mitchell Jay; Røislien, Jo; Brohi, Karim; Heier, Hans Erik; Hestnes, Morten; Gaarder, Christine

    2013-05-01

    Massive haemorrhage is a leading cause of preventable deaths in trauma. Traumatic coagulopathy is frequently present early after trauma, and is associated with increased mortality. A number of recent trials suggest that viscoelastic haemostatic assays (VHA), such as thromboelastography and thromboelastometry, are useful tools in guiding transfusion. Treatment algorithms exist for the use of VHAs but are not validated in traumatic haemorrhage. In this study we examined the inter-changeability of two commonly used VHAs, TEG(®) and RoTEM(®). A total of 184 trauma patients over the age of 18, requiring full trauma team activation, were included at three different hospitals in three different countries (Copenhagen, Denmark, San Francisco, CA, USA and Oslo, Norway). Blood samples were drawn immediately upon arrival, and TEG(®) and RoTEM(®) analyzed simultaneously. Correlations were calculated using. Spearman's rank correlation coefficient. Agreement was evaluated by Bland-Altman plots and calculation of limits of agreement. The mean ISS in the total population was 17, and the mortality was 16.5%. Mean base excess was -2.8 (SD: 4.2). The correlation coefficient for corresponding values for the two devices was 0.24 for the R-time vs CT in all centres combined. For the K-time vs CFT the correlation was 0.48, for the α-angleTEG vs α-angleRoTEM 0.44, and for MA vs MCF 0.76. Limits of agreement exceeded the preset clinically acceptable deviation of 10% for all variables in all centres except for MA/MCF in one centre (Copenhagen). Generally, correlation coefficients were lower and agreement poorer in the one centre (Oslo) where measurements were performed bedside by clinicians. Inter-changeability between TEG(®) and RoTEM(®) is limited in the trauma setting. Agreement seems poorer when clinicians operate the devices. Development and validation of separate treatment algorithms for the two devices is required. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Numerical simulations for quantitative analysis of electrostatic interaction between atomic force microscopy probe and an embedded electrode within a thin dielectric: meshing optimization, sensitivity to potential distribution and impact of cantilever contribution

    Science.gov (United States)

    Azib, M.; Baudoin, F.; Binaud, N.; Villeneuve-Faure, C.; Bugarin, F.; Segonds, S.; Teyssedre, G.

    2018-04-01

    Recent experimental results demonstrated that an electrostatic force distance curve (EFDC) can be used for space charge probing in thin dielectric layers. A main advantage of the method is claimed to be its sensitivity to charge localization, which, however, needs to be substantiated by numerical simulations. In this paper, we have developed a model which permits us to compute an EFDC accurately by using the most sophisticated and accurate geometry for the atomic force microscopy probe. To avoid simplifications and in order to reproduce experimental conditions, the EFDC has been simulated for a system constituted of a polarized electrode embedded in a thin dielectric layer (SiN x ). The individual contributions of forces on the tip and on the cantilever have been analyzed separately to account for possible artefacts. The EFDC sensitivity to potential distribution is studied through the change in electrode shape, namely the width and the depth. Finally, the numerical results have been compared with experimental data.

  5. Enabling Manufacturing Competitiveness and Economic Sustainability : Proceedings of the 4th International Conference on Changeable, Agile, Reconfigurable and Virtual production

    CERN Document Server

    2012-01-01

    The changing manufacturing environment requires more responsive and adaptable manufacturing systems. The theme of the 4th International Conference on Changeable, Agile, Reconfigurable and Virtual production (CARV2011) is “Enabling Manufacturing Competitiveness and Economic Sustainability”. Leading edge research and best implementation practices and experiences, which address these important issues and challenges, are presented. The proceedings include advances in manufacturing systems design, planning, evaluation, control and evolving paradigms such as mass customization, personalization, changeability, re-configurability and flexibility. New and important concepts such as the dynamic product families and platforms, co-evolution of products and systems, and methods for enhancing manufacturing systems’ economic sustainability and prolonging their life to produce more than one product generation are treated. Enablers of change in manufacturing systems, production volume and capability scalability and man...

  6. What Type of Food Can Older Adults Masticate?: Evaluation of Mastication Performance Using Color-Changeable Chewing Gum.

    Science.gov (United States)

    Wada, Shinichi; Kawate, Nobuyuki; Mizuma, Masazumi

    2017-10-01

    This study determines if older adults can masticate regular foods via a simple test conducted using a color-changeable chewing gum. Seventy-nine consecutive inpatients of our clinic receiving rehabilitation and general medicine were assessed for eligibility. The inclusion criterion was >65 years. Thirty patients consented to participate. The main outcome variable was the food bolus texture at the swallowing threshold for five regular foods. The main explanatory variable was the a* value of the color-changeable chewing gum after 120 s of chewing (a* represents the degree of color between red and green, and a positive a* value indicates red). The mean age ± standard deviation of the participants was 81.6 ± 8.6 years, and 40% were men. Participants being able to prepare the food with suitable texture for swallowing was positively associated with the a* values in boiled rice, ginger-fried pork loin, boiled fish-paste, and rice cracker (Crude OR 1.18, 1.15, 1.17, and 1.50; P chewing gum is not only useful but also extremely practical, even for older adults in a wide range of settings, including an individual's home. This approach would lead to a reduction in unnecessary mechanically altered or pureed food for older adults who can eat pureed food and safely provide palatable food.

  7. An optimum design on rollers containing the groove with changeable inner diameter based on response surface methodology

    Directory of Open Access Journals (Sweden)

    Xi Zhao

    2016-05-01

    Full Text Available In order to realize the precision plastic forming of the revolving body component with changeable wall thickness, a kind of roller containing grooves with changeable inner diameter is put forward, as the forming mould of the technology of rolling-extrusion. Specifically, first, the arc length of the groove in the roller is designed according to the prediction on the forward slip value during the process of forming, to make accurate control of the actual length of the forming segments; then, to obtain better parameters of the roller structure, a second-order response surface model combining finite element numerical simulation and response surface methodology was put forward, taking the factor of forming uniformity as evaluation index. The result of the experiment shows that, for the formed component, not only the size can meet the needs but also each mechanical property index can be greatly improved, which verify the rationality of the forward slip model and the structural parameter of the optimum model based on the response surface methodology.

  8. Perceived consequences, changeability and personal control of coronary heart disease are associated with health-related quality of life.

    Science.gov (United States)

    Sigurdardottir, Arun K; Sigurlásdóttir, Kolbrún; Ólafsson, Kjartan; Svavarsdóttir, Margrét Hrönn

    2017-11-01

    To explore changes in illness perception and health-related quality of life in patients with coronary heart disease following percutaneous coronary intervention from the time when patients were discharged from hospital and five months later and to investigate association between illness perception and physical and mental health-related quality of life at five-month follow-up. Illness perception is known to influence patients' motivation to engage in preventive behaviour. Prospective and comparative with two measurement points: at discharge from hospital (time 1) and five months later (time 2). Two self-administered questionnaires were used as follows: the Illness Perception Questionnaire-Revised measured illness perception and the Short Form Health Survey (SF-36) measured physical and mental health-related quality of life. The sample consisted of patients with coronary heart disease admitted to University Hospital between November 2011-April 2012. A total of 69 questionnaires were returned for both measurement times. Most responders were male (71%), mean age was 68·9 (SD 10·3) years. Health-related quality of life increased over time, and illness perception changed; five months after discharge, participants were more aware that the disease was chronic and could worsen suddenly, and they perceived that the disease had less of a consequence on their lives compared to when they were staying in the hospital. Associations between increased personal control, changeability of the disease, perceptions of less of a consequence of the disease on daily life and increased health-related quality of life were demonstrated at time 2. Perceptions of personal control, changeability and consequences of the disease should be assessed and discussed with cardiac patients, as these illness perceptions are related to physical and mental health-related quality of life. Increased understanding of consequences of the disease, personal control and perceived changeability of the illness

  9. THE INFLUENCE OF INTERCROPS AND FARMYARD MANURE FERTILIZATION IN CHANGEABLE WEATHER CONDITIONS ON CONSUMPTION VALUE OF POTATO TUBERS

    Directory of Open Access Journals (Sweden)

    ANNA PŁAZA

    2010-10-01

    Full Text Available The paper presents the results of research carried out over 1999-2002 with the aims to determine the influence of intercrops and farmyard manure fertilization on consumption value of potato tubers in changeable weather conditions. The following combinations of intercrops fertilization were taken into account: the control plot (without intercrop fertilization, farmyard manure, undersown crop (birdsfoot trefoil, birdsfoot trefoil + Italian ryegrass, Italian ryegrass, stubble crop (oleiferous radish, oleiferous radish – mulch. The results pointed that, the conditions of vegetation period, significantly modified the consumption values of potato tubers. The consumption value of potato tubers which were fertilized with intercrops was formed on approximated level, as the potato which was fertilized with farmyard manure. The best consumption features, especially taste, had potatoes which were fertilized with birdsfoot trefoil and with the mixture of birdsfoot trefoil and Italian ryegrass.

  10. Liquid electrode

    Science.gov (United States)

    Ekechukwu, A.A.

    1994-07-05

    A dropping electrolyte electrode is described for use in electrochemical analysis of non-polar sample solutions, such as benzene or cyclohexane. The liquid electrode, preferably an aqueous salt solution immiscible in the sample solution, is introduced into the solution in dropwise fashion from a capillary. The electrolyte is introduced at a known rate, thus, the droplets each have the same volume and surface area. The electrode is used in making standard electrochemical measurements in order to determine properties of non-polar sample solutions. 2 figures.

  11. electrode array

    African Journals Online (AJOL)

    PROF EKWUEME

    A geoelectric investigation employing vertical electrical soundings (VES) using the Ajayi - Makinde Two-Electrode array and the ... arrangements used in electrical D.C. resistivity survey. These include ..... Refraction Tomography to Study the.

  12. Technique eliminates high voltage arcing at electrode-insulator contact area

    Science.gov (United States)

    Mealy, G.

    1967-01-01

    Coating the electrode-insulator contact area with silver epoxy conductive paint and forcing the electrode and insulator tightly together into a permanent connection, eliminates electrical arcing in high-voltage electrodes supplying electrical power to vacuum facilities.

  13. Cermet electrode

    Science.gov (United States)

    Maskalick, Nicholas J.

    1988-08-30

    Disclosed is a cermet electrode consisting of metal particles of nickel, cobalt, iron, or alloys or mixtures thereof immobilized by zirconia stabilized in cubic form which contains discrete deposits of about 0.1 to about 5% by weight of praseodymium, dysprosium, terbium, or a mixture thereof. The solid oxide electrode can be made by covering a substrate with particles of nickel, cobalt, iron, or mixtures thereof, growing a stabilized zirconia solid oxide skeleton around the particles thereby immobilizing them, contacting the skeleton with a compound of praseodymium, dysprosium, terbium, or a mixture thereof, and heating the skeleton to a temperature of at least 500.degree. C. The electrode can also be made by preparing a slurry of nickel, cobalt, iron, or mixture and a compound of praseodymium, dysprosium, terbium, or a mixture thereof, depositing the slurry on a substrate, heating the slurry to dryness, and growing a stabilized zirconia skeleton around the metal particles.

  14. Design and experimental research of a novel inchworm type piezo-driven rotary actuator with the changeable clamping radius.

    Science.gov (United States)

    Zhao, Hongwei; Fu, Lu; Ren, Luquan; Huang, Hu; Fan, Zunqiang; Li, Jianping; Qu, Han

    2013-01-01

    In this paper, a novel piezo-driven rotary actuator with the changeable clamping radius is developed based on the inchworm principle. This actuator mainly utilizes three piezoelectric actuators, a flexible gripper, a clamping block, and a rotor to achieve large stroke rotation with high resolution. The design process of the flexible gripper consisting of the driving unit and the clamping unit is described. Lever-type mechanisms were used to amplify the micro clamping displacements. The amplifying factor and parasitic displacement of the lever-type mechanism in the clamping unit was analyzed theoretically and experimentally. In order to investigate the rotation characteristics of the actuator, a series of experiments was carried out. Experimental results indicate that the actuator can rotate at a speed of 77,488 μrad/s with a driving frequency of 167 Hz. The rotation resolution and maximum load torque of the actuator are 0.25 μrad and 37 N mm, respectively. The gripper is movable along the z direction based on an elevating platform, and the clamping radius can change from 10.6 mm to 25 mm. Experimental results confirm that the actuator can achieve different rotation speeds by changing the clamping radius.

  15. A new magnetorheological mount featured by changeable damping gaps using a moved-plate valve structure

    International Nuclear Information System (INIS)

    Phu, Do Xuan; Shah, Kruti; Choi, Seung-Bok

    2014-01-01

    In this work, a new type of a magnetorheological (MR) fluid mount is proposed and its performances are experimentally investigated. The design of this MR mount is based on two operating modes of MR fluid: flow mode and shear mode. These modes are applied to the mechanism design consisting of two components: a fixed plate for applying the flow mode, and a moved plate for applying the shear mode of MR fluid motion. These plates belong to the valve-type structure of MR mount. The primary objective using the moved plate is to overcome the block-up phenomenon which frequently occurs in the conventional-type MR mount, in which there is no flow of MR fluid through the damping gap. In this research, a laboratorial fluid (MRF140) is used in the design and optimization of MR mount. This fluid features plate-like particles unlike the sphere particles. The yield stress of the fluid is measured as a function of the magnetic field and the theoretical analysis for the mount design is undertaken using the properties of the MR fluid, followed by design optimization. The objective function is concentrated on maximal damping force of the MR mount subjected to parameter constraints. Based on the results of optimization, the proposed MR mount is manufactured and tested for the performance evaluation. Vibration control capability and block-up phenomenon are investigated and compared between the proposed and conventional MR mounts. (paper)

  16. Magnetohydrodynamic electrode

    International Nuclear Information System (INIS)

    1980-01-01

    The object of the invention is the provision of a material capable of withstanding a high-temperature, corrosive and erosive environment for use as a ceramic-metal composite electrode current collector in the channel of a magnetohydrodynamic generator. (U.K.)

  17. Association between chewing-stimulated salivary flow under the effects of atropine and mixing ability assessed using a color-changeable chewing gum.

    Science.gov (United States)

    Kubota, Chieko; Kanazawa, Manabu; Hama, Yohei; Komagamine, Yuriko; Minakuchi, Shunsuke

    2017-10-01

    To assess the time course of chewing-stimulated salivary flow after oral atropine administration, and determine the association between chewing-stimulated salivary flow and mixing ability using color-changeable chewing gum in dentate adults. Ten healthy dentate adults were administered 1mg oral atropine to induce mouth dryness. The subjects' chewing-stimulated salivary flow was assessed using the Saxon test. They were then asked to rinse their mouth with tap water for 15s, and to chew on color-changeable chewing gum for 60s at a constant rate of 60 cycles per min. This procedure was performed before, and at 10-min intervals for up to 120min after the atropine administration. The experiment was repeated after 1 week. Steel's test was used to compare the chewing-stimulated salivary flow rates at each time point after atropine administration with the baseline value. The effect of the stimulated salivary flow rates on the degree of color change was analyzed using linear mixed effects models, with the stimulated salivary flow rates as fixed factors and subjects as the random factor. Chewing-stimulated salivary flow showed a significant decrease from 50 to 120min after oral atropine administration (Pchewing-stimulated salivary flow had a significant effect on the color change of the color-changeable chewing gum (Pchewing gum and chewing-stimulated salivary flow in dentate subjects. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  18. Schiff Base modified on CPE electrode and PCB gold electrode for selective determination of silver ion

    Science.gov (United States)

    Leepheng, Piyawan; Suramitr, Songwut; Phromyothin, Darinee

    2017-09-01

    The schiff base was synthesized by 2,5-thiophenedicarboxaldehyde and 1,2,4-thiadiazole-3,5-diamine with condensation method. There was modified on carbon paste electrode (CPE) and Printed circuit board (PCB) gold electrode for determination silver ion. The schiff base modified electrodes was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM), respectively. The electrochemical study was reported by cyclic voltammetry method and impedance spectroscopy using modified electrode as working electrode, platinum wire and Ag/AgCl as counter electrode and reference electrode, respectively. The modified electrodes have suitable detection for Ag+. The determination of silver ions using the modified electrodes depended linearly on Ag+ concentration in the range 1×10-10 M to 1×10-7 M, with cyclic voltammetry sensitivity were 2.51×108 μAM-1 and 1.88×108 μAM-1 for PCB gold electrode and CPE electrode, respectively, limits of detection were 5.33×10-9 M and 1.99×10-8 M for PCB gold electrode and CPE electrode, respectively. The modified electrodes have high accuracy, inexpensive and can applied to detection Ag+ in real samples.

  19. Electrode Processes in Porous Electrodes.

    Science.gov (United States)

    1985-11-26

    F104470 2.0 MASS SPECTROMETRY One part of activity for this year is an investigation of the behavior of silver electrodes through the distribution of...al. (2)). These, in some cases, involve tedious and time comsuming procedures and discrepencies of as much as 15% have been observed in the results. As

  20. Dependence of streamer density on electric field strength on positive electrode

    Science.gov (United States)

    Koki, Nakamura; Takahumi, Okuyama; Wang, Douyan; Takao, N.; Hidenori, Akiyama; Kumamoto University Collaboration

    2015-09-01

    Pulsed streamer discharge plasma, a type of non-thermal plasma, is known as generation method of reactive radicals and ozone and treatment of exhausted gas. From our previous research, the distance between electrodes has been considered a very important parameter for applications using pulsed streamer discharge. However, how the distance between electrodes affects the pulsed discharge hasn't been clarified. In this research, the propagation process of pulsed streamer discharge in a wire-plate electrode was observed using an ICCD camera for 4 electrodes having different distance between electrodes. The distance between electrodes was changeable at 45 mm, 40 mm, 35 mm, and 30 mm. The results show that, when the distance between electrodes was shortened, applied voltage with a pulse duration of 100 ns decreased from 80 to 60.3 kV. Conversely, discharge current increased from 149 to 190 A. Streamer head velocity became faster. On the other hand, Streamer head density at onset time of streamer head propagation didn't change. This is considered due to the electric field strength of streamer head at that time, in result, it was about 14 kV/mm under each distance between electrodes.

  1. The origin of human complex diversity: Stochastic epistatic modules and the intrinsic compatibility between distributional robustness and phenotypic changeability.

    Science.gov (United States)

    Ijichi, Shinji; Ijichi, Naomi; Ijichi, Yukina; Imamura, Chikako; Sameshima, Hisami; Kawaike, Yoichi; Morioka, Hirofumi

    2018-01-01

    The continuing prevalence of a highly heritable and hypo-reproductive extreme tail of a human neurobehavioral quantitative diversity suggests the possibility that the reproductive majority retains the genetic mechanism for the extremes. From the perspective of stochastic epistasis, the effect of an epistatic modifier variant can randomly vary in both phenotypic value and effect direction among the careers depending on the genetic individuality, and the modifier careers are ubiquitous in the population distribution. The neutrality of the mean genetic effect in the careers warrants the survival of the variant under selection pressures. Functionally or metabolically related modifier variants make an epistatic network module and dozens of modules may be involved in the phenotype. To assess the significance of stochastic epistasis, a simplified module-based model was employed. The individual repertoire of the modifier variants in a module also participates in the genetic individuality which determines the genetic contribution of each modifier in the career. Because the entire contribution of a module to the phenotypic outcome is consequently unpredictable in the model, the module effect represents the total contribution of the related modifiers as a stochastic unit in the simulations. As a result, the intrinsic compatibility between distributional robustness and quantitative changeability could mathematically be simulated using the model. The artificial normal distribution shape in large-sized simulations was preserved in each generation even if the lowest fitness tail was un-reproductive. The robustness of normality beyond generations is analogous to the real situations of human complex diversity including neurodevelopmental conditions. The repeated regeneration of the un-reproductive extreme tail may be inevitable for the reproductive majority's competence to survive and change, suggesting implications of the extremes for others. Further model-simulations to

  2. Electrodes for Semiconductor Gas Sensors

    Science.gov (United States)

    Lee, Sung Pil

    2017-01-01

    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. PMID:28346349

  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. Design, fabrication and skin-electrode contact analysis of polymer microneedle-based ECG electrodes

    International Nuclear Information System (INIS)

    O’Mahony, Conor; Grygoryev, Konstantin; Ciarlone, Antonio; Giannoni, Giuseppe; Kenthao, Anan; Galvin, Paul

    2016-01-01

    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. (paper)

  5. Forces in Liquid Metal Contacts

    DEFF Research Database (Denmark)

    Duggen, Lars; Mátéfi-Tempfli, Stefan

    2014-01-01

    Using rather well known theory about capillary bridges between two electrodes we calculate the tensile force that can be applied to liquid metal contacts in the micrometer regime. Assuming circular symmetry, full wetting of the electrodes, and neglecting gravity, we present a brief review of the ...... of the necessary theory and find numerically the forces to be in the 100μN range for liquid metals as mercury and liquid Gallium suspended between electrodes of 20μm radius.......Using rather well known theory about capillary bridges between two electrodes we calculate the tensile force that can be applied to liquid metal contacts in the micrometer regime. Assuming circular symmetry, full wetting of the electrodes, and neglecting gravity, we present a brief review...

  6. Force on an Asymmetric Capacitor

    National Research Council Canada - National Science Library

    Bahder, Thomas

    2003-01-01

    .... At present, the physical basis for the Biefeld-Brown effect is not understood. The order of magnitude of the net force on the asymmetric capacitor is estimated assuming two different mechanisms of charge conduction between its electrodes...

  7. The investigation of movement dynamics of an AC electric arc attachment along the working surface of a hollow cylindrical electrode under the action of gas-dynamic and electromagnetic forces

    International Nuclear Information System (INIS)

    Surov, A V; Popov, S D; Serba, E O; Nakonechny, G V; Spodobin, V A; Ovchinnikov, R V; Kumkova, I I; Shabalin, S A

    2012-01-01

    Stationary electric arc alternating current plasma torches are used today for realization of plasma chemical technologies requiring relatively high energy input. Waste treatment is one these directions. The paper reports on experiment results directed towards the increase in the lifetime characteristics of electrode units of the powerful high-voltage electric-arc AC plasma torches. The solution to the problem of obtainment the uniform wear of a copper hollow cylindrical electrode achieved by the controlled movement of the arc attachment along the working surface was offered. Organization of gas supply in the near electrode area and application of alternating magnetic field ensured movement of arc attachment along the surface with average speed from 2 to 14 m/s. Arc current was about 47 A and 84 A, gas flow rate in near electrode area was about 5 and 4.5 g/s. Due to researches on the experimental prototype of a hollow cylindrical electrode, the erosion of its material reached only 3 μg/C, that enables production of the electrode assembly with life time above 1000 hours at currents in the arc up to 100–200 A.

  8. Using high-level construal and perceptions of changeability to promote self-change over self-protection motives in response to negative feedback.

    Science.gov (United States)

    Belding, Jennifer N; Naufel, Karen Z; Fujita, Kentaro

    2015-06-01

    Diagnostic negative information presents people with a motivational dilemma. Although negative feedback can provide useful information with which to guide future self-improvement efforts, it also presents short-term affective costs. We propose that construal level, jointly with the perceived changeability of the feedback domain, determines whether people choose to accept or dismiss such information. Whereas low-level construal promotes short-term self-protection motivation (promoting dismissal), high-level construal promotes long-term self-change motivation (promoting acceptance)--to the extent that change is perceived as possible. Four studies support this hypothesis and examine underlying cognitive and motivational mechanisms. The present work may provide an integrative theoretical framework for understanding when people will be open to and accept negative diagnostic information, and has important practical implications for promoting self-change efforts. © 2015 by the Society for Personality and Social Psychology, Inc.

  9. High performance cermet electrodes

    Science.gov (United States)

    Isenberg, Arnold O.; Zymboly, Gregory E.

    1986-01-01

    Disclosed is a method of increasing the operating cell voltage of a solid oxide electrochemical cell having metal electrode particles in contact with an oxygen-transporting ceramic electrolyte. The metal electrode is heated with the cell, and oxygen is passed through the oxygen-transporting ceramic electrolyte to the surface of the metal electrode particles so that the metal electrode particles are oxidized to form a metal oxide layer between the metal electrode particles and the electrolyte. The metal oxide layer is then reduced to form porous metal between the metal electrode particles and the ceramic electrolyte.

  10. 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…

  11. The Composite Insertion Electrode

    DEFF Research Database (Denmark)

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

    1984-01-01

    The specific energy obtainable by discharge of porous insertion electrodes is limited by electrolyte depletion in thepores. This can be overcome using a solid ion conductor as electrolyte. The term "composite" is used to distinguishthese electrodes from porous electrodes with liquid electrolyte...

  12. Near-Electrode Imager

    Energy Technology Data Exchange (ETDEWEB)

    Rathke, Jerome W.; Klingler, Robert J.; Woelk, Klaus; Gerald, Rex E.,II

    1999-05-01

    An apparatus, near-electrode imager, for employing nuclear magnetic resonance imaging to provide in situ measurements of electrochemical properties of a sample as a function of distance from a working electrode. The near-electrode imager use the radio frequency field gradient within a cylindrical toroid cavity resonator to provide high-resolution nuclear magnetic resonance spectral information on electrolyte materials.

  13. EFFECTS OF ELECTRODE DEFORMATION OF RESISTANCE SPOT WELDING ON 304 AUSTENITIC STAINLESS STEEL WELD GEOMETRY

    Directory of Open Access Journals (Sweden)

    Nachimani Charde

    2012-12-01

    Full Text Available The resistance spot welding process is accomplished by forcing huge amounts of current flow from the upper electrode tip through the base metals to the lower electrode tip, or vice versa or in both directions. A weld joint is established between the metal sheets through fusion, resulting in a strong bond between the sheets without occupying additional space. The growth of the weld nugget (bond between sheets is therefore determined from the welding current density; sufficient time for current delivery; reasonable electrode pressing force; and the area provided for current delivery (electrode tip. The welding current and weld time control the root penetration, while the electrode pressing force and electrode tips successfully accomplish the connection during the welding process. Although the welding current and weld time cause the heat generation at the areas concerned (electrode tip area, the electrode tips’ diameter and electrode pressing forces also directly influence the welding process. In this research truncated-electrode deformation and mushrooming effects are observed, which result in the welded areas being inconsistent due to the expulsion. The copper to chromium ratio is varied from the tip to the end of the electrode whilst the welding process is repeated. The welding heat affects the electrode and the electrode itself influences the shape of the weld geometry.

  14. Continuous separation of submicron particles using Angled electrodes

    International Nuclear Information System (INIS)

    Yunus, Nurul A Md; Green, Nicolas G

    2008-01-01

    Dielectrophoretic separation of particles is achieved by the generation of electric forces on the particles by non-uniform electric fields. This paper presents a technique based on negative dielectrophoresis in a novel design of electrode array for the non-contact separation of polarisable particles. Angled electrodes are used to generate a lateral force in a microfluidic channel separating a mixed stream of particles into distinct streams of constituent components and achieving a high degree of spatial separation.

  15. Wind tunnel tests for a flapping wing model with a changeable camber using macro-fiber composite actuators

    International Nuclear Information System (INIS)

    Kim, Dae-Kwan; Han, Jae-Hung; Kwon, Ki-Jung

    2009-01-01

    In the present study, a biomimetic flexible flapping wing was developed on a real ornithopter scale by using macro-fiber composite (MFC) actuators. With the actuators, the maximum camber of the wing can be linearly changed from −2.6% to +4.4% of the maximum chord length. Aerodynamic tests were carried out in a low-speed wind tunnel to investigate the aerodynamic characteristics, particularly the camber effect, the chordwise flexibility effect and the unsteady effect. Although the chordwise wing flexibility reduces the effective angle of attack, the maximum lift coefficient can be increased by the MFC actuators up to 24.4% in a static condition. Note also that the mean values of the perpendicular force coefficient rise to a value of considerably more than 3 in an unsteady aerodynamic flow region. Additionally, particle image velocimetry (PIV) tests were performed in static and dynamic test conditions to validate the flexibility and unsteady effects. The static PIV results confirm that the effective angle of attack is reduced by the coupling of the chordwise flexibility and the aerodynamic force, resulting in a delay in the stall phenomena. In contrast to the quasi-steady flow condition of a relatively high advance ratio, the unsteady aerodynamic effect due to a leading edge vortex can be found along the wing span in a low advance ratio region. The overall results show that the chordwise wing flexibility can produce a positive effect on flapping aerodynamic characteristics in quasi-steady and unsteady flow regions; thus, wing flexibility should be considered in the design of efficient flapping wings

  16. Modiolus-Hugging Intracochlear Electrode Array with Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Kyou Sik Min

    2013-01-01

    Full Text Available In the cochlear implant system, the distance between spiral ganglia and the electrodes within the volume of the scala tympani cavity significantly affects the efficiency of the electrical stimulation in terms of the threshold current level and spatial selectivity. Because the spiral ganglia are situated inside the modiolus, the central axis of the cochlea, it is desirable that the electrode array hugs the modiolus to minimize the distance between the electrodes and the ganglia. In the present study, we propose a shape-memory-alloy-(SMA- embedded intracochlear electrode which gives a straight electrode a curved modiolus-hugging shape using the restoration force of the SMA as triggered by resistive heating after insertion into the cochlea. An eight-channel ball-type electrode array is fabricated with an embedded titanium-nickel SMA backbone wire. It is demonstrated that the electrode array changes its shape in a transparent plastic human cochlear model. To verify the safe insertion of the electrode array into the human cochlea, the contact pressures during insertion at the electrode tip and the contact pressures over the electrode length after insertion were calculated using a 3D finite element analysis. The results indicate that the SMA-embedded electrode is functionally and mechanically feasible for clinical applications.

  17. Uncharged positive electrode composition

    Science.gov (United States)

    Kaun, Thomas D.; Vissers, Donald R.; Shimotake, Hiroshi

    1977-03-08

    An uncharged positive-electrode composition contains particulate lithium sulfide, another alkali metal or alkaline earth metal compound other than sulfide, e.g., lithium carbide, and a transition metal powder. The composition along with a binder, such as electrolytic salt or a thermosetting resin is applied onto an electrically conductive substrate to form a plaque. The plaque is assembled as a positive electrode within an electrochemical cell opposite to a negative electrode containing a material such as aluminum or silicon for alloying with lithium. During charging, lithium alloy is formed within the negative electrode and transition metal sulfide such as iron sulfide is produced within the positive electrode. Excess negative electrode capacity over that from the transition metal sulfide is provided due to the electrochemical reaction of the other than sulfide alkali metal or alkaline earth metal compound.

  18. 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

  19. Comprehensive Study of Microgel Electrode for On-Chip Electrophoretic Cell Sorting

    Science.gov (United States)

    Hattori, Akihiro; Yasuda, Kenji

    2010-06-01

    We have developed an on-chip cell sorting system and microgel electrode for applying electrostatic force in microfluidic pathways in the chip. The advantages of agarose electrodes are 1) current-driven electrostatic force generation, 2) stability against pH change and chemicals, and 3) no bubble formation caused by electrolysis. We examined the carrier ion type and concentration dependence of microgel electrode impedance, and found that CoCl2 has less than 1/10 of the impedance from NaCl, and the reduction of the impedance of NaCl gel electrode was plateaued at 0.5 M. The structure control of the microgel electrode exploiting the surface tension of sol-state agarose was also introduced. The addition of 1% (w/v) trehalose into the microgel electrode allowed the frozen storage of the microgel electrode chip. The experimental results demonstrate the potential of our system and microgel electrode for practical applications in microfluidic chips.

  20. Printed optically transparent graphene cellulose electrodes

    Science.gov (United States)

    Sinar, Dogan; Knopf, George K.; Nikumb, Suwas; Andrushchenko, Anatoly

    2016-02-01

    Optically transparent electrodes are a key component in variety of products including bioelectronics, touch screens, flexible displays, low emissivity windows, and photovoltaic cells. Although highly conductive indium tin oxide (ITO) films are often used in these electrode applications, the raw material is very expensive and the electrodes often fracture when mechanically stressed. An alternative low-cost material for inkjet printing transparent electrodes on glass and flexible polymer substrates is described in this paper. The water based ink is created by using a hydrophilic cellulose derivative, carboxymethyl cellulose (CMC), to help suspend the naturally hydrophobic graphene (G) sheets in a solvent composed of 70% DI water and 30% 2-butoxyethanol. The CMC chain has hydrophobic and hydrophilic functional sites which allow adsorption on G sheets and, therefore, permit the graphene to be stabilized in water by electrostatic and steric forces. Once deposited on the functionalized substrate the electrical conductivity of the printed films can be "tuned" by decomposing the cellulose stabilizer using thermal reduction. The entire electrode can be thermally reduced in an oven or portions of the electrode thermally modified using a laser annealing process. The thermal process can reduce the sheet resistance of G-CMC films to < 100 Ω/sq. Experimental studies show that the optical transmittance and sheet resistance of the G-CMC conductive electrode is a dependent on the film thickness (ie. superimposed printed layers). The printed electrodes have also been doped with AuCl3 to increase electrical conductivity without significantly increasing film thickness and, thereby, maintain high optical transparency.

  1. Electrode stabilizing materials

    Science.gov (United States)

    Amine, Khalil; Abouimrane, Ali; Moore, Jeffrey S.; Odom, Susan A.

    2015-11-03

    An electrolyte includes a polar aprotic solvent; an alkali metal salt; and an electrode stabilizing compound that is a monomer, which when polymerized forms an electrically conductive polymer. The electrode stabilizing compound is a thiophene, a imidazole, a anilines, a benzene, a azulene, a carbazole, or a thiol. Electrochemical devices may incorporate such electrolytes.

  2. Durable fuel electrode

    DEFF Research Database (Denmark)

    2017-01-01

    the composite. The invention also relates to the use of the composite as a fuel electrode, solid oxide fuel cell, and/or solid oxide electrolyser. The invention discloses a composite for an electrode, comprising a three-dimensional network of dispersed metal particles, stabilised zirconia particles and pores...

  3. Electrochemical force microscopy

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-10

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

  4. Electrode-electrolyte interface model of tripolar concentric ring electrode and electrode paste.

    Science.gov (United States)

    Nasrollaholhosseini, Seyed Hadi; Steele, Preston; Besio, Walter G

    2016-08-01

    Electrodes are used to transform ionic currents to electrical currents in biological systems. Modeling the electrode-electrolyte interface could help to optimize the performance of the electrode interface to achieve higher signal to noise ratios. There are previous reports of accurate models for single-element biomedical electrodes. In this paper we develop a model for the electrode-electrolyte interface for tripolar concentric ring electrodes (TCRE) that are used to record brain signals.

  5. Colloidal paradigm in supercapattery electrode systems

    Science.gov (United States)

    Chen, Kunfeng; Xue, Dongfeng

    2018-01-01

    Among decades of development, electrochemical energy storage systems are now sorely in need of a new design paradigm at the nano size and ion level to satisfy the higher energy and power demands. In this review paper, we introduce a new colloidal electrode paradigm for supercapattery that integrates multiple-scale forms of matter, i.e. ion clusters, colloidal ions, and nanosized materials, into one colloid system, coupled with multiple interactions, i.e. electrostatic, van der Waals forces, and chemical bonding, thus leading to the formation of many redox reactive centers. This colloidal electrode not only keeps the original ionic nature in colloidal materials, but also creates a new attribute of high electroactivity. Colloidal supercapattery is a perfect application example of the novel colloidal electrode, leading to higher specific capacitance than traditional electrode materials. The high electroactivity of the colloidal electrode mainly comes from the contribution of exposed reactive centers, owing to the confinement effect of carbon and a binder matrix. Systematic and thorough research on the colloidal system will significantly promote the development of fundamental science and the progress of advanced energy storage technology.

  6. Basic electrochemical properties of sputtered gold film electrodes

    International Nuclear Information System (INIS)

    Libansky, Milan; Zima, Jiri; Barek, Jiri; Reznickova, Alena; Svorcik, Vaclav; Dejmkova, Hana

    2017-01-01

    Gold nanolayers made by sputtering of pure gold (physical vapour deposition) are commonly used for many biophysical and material applications. However, the use of sputtering method for fabrication of working electrodes for electroanalytical purposes is less common. This paper focuses on the testing and characterization of sputtered working roughened gold nanostructured film electrodes, which fall into category of upcoming desirable new generation of nanostructured gold working electrodes. Gold nanostructured films (80 nm thin) were sputtered onto 50 μm thin PTFE substrates with three different types of treatment: pristine, plasma treated, and plasma treated and subsequently spontaneously grafted with biphenyl-4,4′-dithiol. The characterization of gold nanostructured film electrodes was carried out by examination of the electrode reaction of standard redox probes (ferrocyanide/ferricyanide, hydroquinone/benzoquinone) in different types of supporting electrolytes (BR buffers of various pH, KCl, KNO 3 , H 2 SO 4 ), by exploration of the electrode surface by scanning electron microscopy, by atomic force microscopy accompanied by elementary analysis and contact angle measurements. The testing of electrodes was complemented by an attempt to calculate their real surface areas from Randles-Sevcik equation. All results were compared to conventional bulk gold electrode. The practical applicability of the nanostructured gold electrodes as sensors for the determination of environmental pollutants was verified by voltammetric determination of hydroquinone as a model electrochemically oxidisable organic environmental pollutant.

  7. Ring with changeable radiation dosimeter

    International Nuclear Information System (INIS)

    Collica, C.; Epifano, L.; Farella, R.

    1976-01-01

    A ring for housing a disc of radiation measuring material is described comprising a band having a circular shape and a housing integral with the band. The housing comprises a hollow cylindrical section substantially normal to the band surface and terminating in an inwardly disposed annular flange which defines a substantially circular aperture. In a preferred embodiment of the invention a retaining protrusion formed on the inside of the cylindrical section and spaced from the annular flange is provided to retain a plurality of discs mounted in the housing in layered fashion

  8. Cochlear Dummy Electrodes for Insertion Training and Research Purposes: Fabrication, Mechanical Characterization, and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Jan-Philipp Kobler

    2015-01-01

    Full Text Available To develop skills sufficient for hearing preservation cochlear implant surgery, surgeons need to perform several electrode insertion trials in ex vivo temporal bones, thereby consuming relatively expensive electrode carriers. The objectives of this study were to evaluate the insertion characteristics of cochlear electrodes in a plastic scala tympani model and to fabricate radio opaque polymer filament dummy electrodes of equivalent mechanical properties. In addition, this study should aid the design and development of new cochlear electrodes. Automated insertion force measurement is a new technique to reproducibly analyze and evaluate the insertion dynamics and mechanical characteristics of an electrode. Mechanical properties of MED-EL’s FLEX28, FLEX24, and FLEX20 electrodes were assessed with the help of an automated insertion tool. Statistical analysis of the overall mechanical behavior of the electrodes and factors influencing the insertion force are discussed. Radio opaque dummy electrodes of comparable characteristics were fabricated based on insertion force measurements. The platinum-iridium wires were replaced by polymer filament to provide sufficient stiffness to the electrodes and to eradicate the metallic artifacts in X-ray and computed tomography (CT images. These low-cost dummy electrodes are cheap alternatives for surgical training and for in vitro, ex vivo, and in vivo research purposes.

  9. 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....

  10. Investigating the possible effect of electrode support structure on motion artifact in wearable bioelectric signal monitoring.

    Science.gov (United States)

    Cömert, Alper; Hyttinen, Jari

    2015-05-15

    With advances in technology and increasing demand, wearable biosignal monitoring is developing and new applications are emerging. One of the main challenges facing the widespread use of wearable monitoring systems is the motion artifact. The sources of the motion artifact lie in the skin-electrode interface. Reducing the motion and deformation at this interface should have positive effects on signal quality. In this study, we aim to investigate whether the structure supporting the electrode can be designed to reduce the motion artifact with the hypothesis that this can be achieved by stabilizing the skin deformations around the electrode. We compare four textile electrodes with different support structure designs: a soft padding larger than the electrode area, a soft padding larger than the electrode area with a novel skin deformation restricting design, a soft padding the same size as the electrode area, and a rigid support the same size as the electrode. With five subjects and two electrode locations placed over different kinds of tissue at various mounting forces, we simultaneously measured the motion artifact, a motion affected ECG, and the real-time skin-electrode impedance during the application of controlled motion to the electrodes. The design of the electrode support structure has an effect on the generated motion artifact; good design with a skin stabilizing structure makes the electrodes physically more motion artifact resilient, directly affecting signal quality. Increasing the applied mounting force shows a positive effect up to 1,000 gr applied force. The properties of tissue under the electrode are an important factor in the generation of the motion artifact and the functioning of the electrodes. The relationship of motion artifact amplitude to the electrode movement magnitude is seen to be linear for smaller movements. For larger movements, the increase of motion generated a disproportionally larger artifact. The motion artifact and the induced

  11. Analysis and Modelling of Electrode Wear in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Madsen, Anders; Pedersen, Kim; Friis, Kasper Storgaard

    2010-01-01

    A model describing electrode wear as a function of weld number, initial tip diameter, truncated cone angle, welding current and electrode force is proposed. Excellent agreement between the model and experimental results is achieved, showing that the model can describe the change in electrode tip...... diameter with increasing weld number at different weld settings. Furthermore a method for measuring the worn tip diameter in a fast and robust manner is developed. The method relies on a well-known technique for capturing the electrode tip area by the use of carbon imprints and a new developed image...... a central cavity is formed and one where smaller pits are formed randomly across the electrode face. The influence of these two types of surface pits on the nugget size are investigated using the FE code SORPAS, revealing ring welds and undersized weld nuggets....

  12. Developing barbed microtip-based electrode arrays for biopotential measurement.

    Science.gov (United States)

    Hsu, Li-Sheng; Tung, Shu-Wei; Kuo, Che-Hsi; Yang, Yao-Joe

    2014-07-10

    This study involved fabricating barbed microtip-based electrode arrays by using silicon wet etching. KOH anisotropic wet etching was employed to form a standard pyramidal microtip array and HF/HNO3 isotropic etching was used to fabricate barbs on these microtips. To improve the electrical conductance between the tip array on the front side of the wafer and the electrical contact on the back side, a through-silicon via was created during the wet etching process. The experimental results show that the forces required to detach the barbed microtip arrays from human skin, a polydimethylsiloxane (PDMS) polymer, and a polyvinylchloride (PVC) film were larger compared with those required to detach microtip arrays that lacked barbs. The impedances of the skin-electrode interface were measured and the performance levels of the proposed dry electrode were characterized. Electrode prototypes that employed the proposed tip arrays were implemented. Electroencephalogram (EEG) and electrocardiography (ECG) recordings using these electrode prototypes were also demonstrated.

  13. Subatomic forces

    International Nuclear Information System (INIS)

    Sutton, C.

    1989-01-01

    Inside the atom, particles interact through two forces which are never felt in the everyday world. But they may hold the key to the Universe. These ideas on subatomic forces are discussed with respect to the strong force, the electromagnetic force and the electroweak force. (author)

  14. Comparisons of Force Measurement Methods for DBD Plasma Actuators in Quiescent Air

    Science.gov (United States)

    Hoskinson, Alan R.; Hershkowitz, Noah; Ashpis, David E.

    2009-01-01

    We have performed measurements of the force induced by both single (one electrode insulated) and double (both electrodes insulated) dielectric barrier discharge plasma actuators in quiescent air. We have shown that, for single barrier actuators with cylindrical exposed electrodes, as the electrode diameter decrease the force efficiencies increase much faster than a previously reported linear trend. This behavior has been experimentally verified using two different measurement techniques: stagnation probe measurements of the induced flow velocity and direct measurement of the force using an electronic balance. Actuators with rectangular cross-section exposed electrodes do not show the same rapid increase at small thicknesses. We have also shown that the induced force is independent of the material used for the exposed electrode. The same techniques have shown that the induced force of a double barrier actuator increases with decreasing narrow electrode diameter.

  15. Composite carbon foam electrode

    Science.gov (United States)

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

    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.

  16. Porous electrode preparation method

    Science.gov (United States)

    Arons, R.M.; Dusek, J.T.

    1983-10-18

    A porous sintered plaque is provided with a bimodal porosity that is especially well suited for use as an electrode within a molten carbonate fuel cell. The coarse porosity is sufficient for admitting gases into contact with the reaction surfaces while the fine porosity is wetted with and retains molten electrolyte on the reaction sites. The electrode structure is prepared by providing a very fine powder of such as nickel oxide and blending the powder with a suitable decomposable binder to form a solid mass. The mass is comminuted into agglomerate size particles substantially larger than the fine oxide particles and formed into a cohesive compact for subsequent sintering. Sintering is carried out at sufficient conditions to bind the agglomerates together into a porous structure having both coarse and fine porosity. Where lithiated nickel oxide cathodes are prepared, the sintering conditions can be moderate enough to retain substantial quantities of lithium within the electrode for adequate conductivity. 2 figs.

  17. Redox Response of Reduced Graphene Oxide-Modified Glassy Carbon Electrodes to Hydrogen Peroxide and Hydrazine

    Directory of Open Access Journals (Sweden)

    Jun-ichi Anzai

    2013-05-01

    Full Text Available The surface of a glassy carbon (GC electrode was modified with reduced graphene oxide (rGO to evaluate the electrochemical response of the modified GC electrodes to hydrogen peroxide (H2O2 and hydrazine. The electrode potential of the GC electrode was repeatedly scanned from −1.5 to 0.6 V in an aqueous dispersion of graphene oxide (GO to deposit rGO on the surface of the GC electrode. The surface morphology of the modified GC electrode was characterized by scanning electron microscopy (SEM and atomic force microscopy (AFM. SEM and AFM observations revealed that aggregated rGO was deposited on the GC electrode, forming a rather rough surface. The rGO-modified electrodes exhibited significantly higher responses in redox reactions of H2O2 as compared with the response of an unmodified GC electrode. In addition, the electrocatalytic activity of the rGO-modified electrode to hydrazine oxidation was also higher than that of the unmodified GC electrode. The response of the rGO-modified electrode was rationalized based on the higher catalytic activity of rGO to the redox reactions of H2O2 and hydrazine. The results suggest that rGO-modified electrodes are useful for constructing electrochemical sensors.

  18. Sandwich-type electrode

    Science.gov (United States)

    Lu, Wen-Tong P.; Garcia, Earl R.

    1983-01-01

    Disclosed is an improvement on a method of making an electrode wherein a suspension in a liquid is prepared of a powdered catalyst containing a noble metal, carbon powder and a binder, and the suspension is poured over a carbon substrate dried, compressed and sintered to form a solid catalyst layer bonded to the carbon substrate. The improvement is placing a carbon paper on the catalyst layer prior to compressing. The improved electrode can be used as either a cathode or an anode in a sulfur dioxide depolarized electrolyzer in a process for producing hydrogen from water.

  19. Ion-selective electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mikhelson, Konstantin N. [St. Petersburg State Univ. (Russian Federation). Ion-Selective Electrode Laboratory

    2013-06-01

    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 ISEs are outlined, and the transfer of methods into routine analysis is considered.

  20. Single Electrode Heat Effects

    DEFF Research Database (Denmark)

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

    1977-01-01

    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......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...

  1. 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

  2. Virtual electrodes for high-density electrode arrays

    Science.gov (United States)

    Cela, Carlos J.; Lazzi, Gianluca

    2015-10-13

    The present embodiments are directed to implantable electrode arrays having virtual electrodes. The virtual electrodes may improve the resolution of the implantable electrode array without the burden of corresponding complexity of electronic circuitry and wiring. In a particular embodiment, a virtual electrode may include one or more passive elements to help steer current to a specific location between the active electrodes. For example, a passive element may be a metalized layer on a substrate that is adjacent to, but not directly connected to an active electrode. In certain embodiments, an active electrode may be directly coupled to a power source via a conductive connection. Beneficially, the passive elements may help to increase the overall resolution of the implantable array by providing additional stimulation points without requiring additional wiring or driver circuitry for the passive elements.

  3. Flexible electrode belt for EIT using nanofiber web dry electrodes.

    Science.gov (United States)

    Oh, Tong In; Kim, Tae Eui; Yoon, Sun; Kim, Kap Jin; Woo, Eung Je; Sadleir, Rosalind J

    2012-10-01

    Efficient connection of multiple electrodes to the body for impedance measurement and voltage monitoring applications is of critical importance to measurement quality and practicality. Electrical impedance tomography (EIT) experiments have generally required a cumbersome procedure to attach the multiple electrodes needed in EIT. Once placed, these electrodes must then maintain good contact with the skin during measurements that may last several hours. There is usually also the need to manage the wires that run between the electrodes and the EIT system. These problems become more severe as the number of electrodes increases, and may limit the practicality and portability of this imaging method. There have been several trials describing human-electrode interfaces using configurations such as electrode belts, helmets or rings. In this paper, we describe an electrode belt we developed for long-term EIT monitoring of human lung ventilation. The belt included 16 embossed electrodes that were designed to make good contact with the skin. The electrodes were fabricated using an Ag-plated PVDF nanofiber web and metallic threads. A large contact area and padding were used behind each electrode to improve subject comfort and reduce contact impedances. The electrodes were incorporated, equally spaced, into an elasticated fabric belt. We tested the electrode belt in conjunction with the KHU Mark1 multi-frequency EIT system, and demonstrate time-difference images of phantoms and human subjects during normal breathing and running. We found that the Ag-plated PVDF nanofiber web electrodes were suitable for long-term measurement because of their flexibility and durability. Moreover, the contact impedance and stability of the Ag-plated PVDF nanofiber web electrodes were found to be comparable to similarly tested Ag/AgCl electrodes.

  4. Protected electrodes for plasma panels

    International Nuclear Information System (INIS)

    Hall, S.W.

    1984-01-01

    A metal oxide coating is applied between the conductive base and the magnesium oxide dielectric of the input and/or erase electrode(s) in a plasma display device to prevent break-down of the dielectric

  5. 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.

  6. Standard electrode potential, Tafel equation, and the solvation thermodynamics.

    Science.gov (United States)

    Matyushov, Dmitry V

    2009-06-21

    Equilibrium in the electronic subsystem across the solution-metal interface is considered to connect the standard electrode potential to the statistics of localized electronic states in solution. We argue that a correct derivation of the Nernst equation for the electrode potential requires a careful separation of the relevant time scales. An equation for the standard metal potential is derived linking it to the thermodynamics of solvation. The Anderson-Newns model for electronic delocalization between the solution and the electrode is combined with a bilinear model of solute-solvent coupling introducing nonlinear solvation into the theory of heterogeneous electron transfer. We therefore are capable of addressing the question of how nonlinear solvation affects electrochemical observables. The transfer coefficient of electrode kinetics is shown to be equal to the derivative of the free energy, or generalized force, required to shift the unoccupied electronic level in the bulk. The transfer coefficient thus directly quantifies the extent of nonlinear solvation of the redox couple. The current model allows the transfer coefficient to deviate from the value of 0.5 of the linear solvation models at zero electrode overpotential. The electrode current curves become asymmetric in respect to the change in the sign of the electrode overpotential.

  7. Copper nanoparticle modified carbon electrode for determination of dopamine

    International Nuclear Information System (INIS)

    Oztekin, Yasemin; Tok, Mutahire; Bilici, Esra; Mikoliunaite, Lina; Yazicigil, Zafer; Ramanaviciene, Almira; Ramanavicius, Arunas

    2012-01-01

    This paper reports the synthesis and characterization of copper nanoparticles (CuNPs) and application of copper nanoparticle-modified glassy carbon electrode for the electrochemical determination of dopamine. Electrochemical measurements were performed using differently modified glassy carbon (GC) electrodes. Bare, oxidized before modification and copper nanoparticle-modified glassy carbon electrodes (bare-GC, ox-GC and CuNP/GC electrodes, respectively) were characterized by cyclic voltammetry and electrochemical impedance spectroscopy in the presence of redox probes. Atomic force microscopy was used for the visualization of electrode surfaces. The CuNP/GC electrode was found to be suitable for the selective determination of dopamine even in the presence of ascorbic acid, uric acid, and p-acetamidophenol. The observed linear range of CuNP/GC for dopamine was from 0.1 nM to 1.0 μM while the detection limit was estimated to be 50 pM. It was demonstrated that here reported glassy carbon electrode modified by copper nanoparticles is suitable for the determination of dopamine in real samples such as human blood serum.

  8. 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.

  9. Electrostatic Levitator Electrode Layout

    Science.gov (United States)

    1998-01-01

    Schematic of Electrostatic Levitator (ESL) electrodes and controls system. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  10. 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

    2015-09-01

    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 ([Formula: see text]) 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).

  11. Flexible transparent electrode

    Science.gov (United States)

    Demiryont, Hulya; Shannon, Kenneth C., III; Moorehead, David; Bratcher, Matthew

    2011-06-01

    This paper presents the properties of the EclipseTECTM transparent conductor. EclipseTECTM is a room temperature deposited nanostructured thin film coating system comprised of metal-oxide semiconductor elements. The system possesses metal-like conductivity and glass-like transparency in the visible region. These highly conductive TEC films exhibit high shielding efficiency (35dB at 1 to 100GHz). EclipseTECTM can be deposited on rigid or flexible substrates. For example, EclipseTECTM deposited on polyethylene terephthalate (PET) is extremely flexible that can be rolled around a 9mm diameter cylinder with little or no reduction in electrical conductivity and that can assume pre-extension states after an applied stress is relieved. The TEC is colorless and has been tailored to have high visible transmittance which matches the eye sensitivity curve and allows the viewing of true background colors through the coating. EclipseTECTM is flexible, durable and can be tailored at the interface for applications such as electron- or hole-injecting OLED electrodes as well as electrodes in flexible displays. Tunable work function and optical design flexibility also make EclipseTECTM well-suited as a candidate for grid electrode replacement in next-generation photovoltaic cells.

  12. Labor Force

    Science.gov (United States)

    Occupational Outlook Quarterly, 2012

    2012-01-01

    The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two…

  13. Non-invasive method for selection of electrodes and stimulus parameters for FES applications with intrafascicular arrays

    Science.gov (United States)

    Dowden, B. R.; Frankel, M. A.; Normann, R. A.; Clark, G. A.

    2012-02-01

    High-channel-count intrafascicular electrode arrays provide comprehensive and selective access to the peripheral nervous system. One practical difficulty in using several electrode arrays to evoke coordinated movements in paralyzed limbs is the identification of the appropriate stimulation channels and stimulus parameters to evoke desired movements. Here we present the use of a six degree-of-freedom load cell placed under the foot of a feline to characterize the muscle activation produced by three 100-electrode Utah Slanted Electrode Arrays (USEAs) implanted into the femoral nerves, sciatic nerves, and muscular branches of the sciatic nerves of three cats. Intramuscular stimulation was used to identify the endpoint force directions produced by 15 muscles of the hind limb, and these directions were used to classify the forces produced by each intrafascicular USEA electrode as flexion or extension. For 451 USEA electrodes, stimulus intensities for threshold and saturation muscle forces were identified, and the 3D direction and linearity of the force recruitment curves were determined. Further, motor unit excitation independence for 198 electrode pairs was measured using the refractory technique. This study demonstrates the utility of 3D endpoint force monitoring as a simple and non-invasive metric for characterizing the muscle-activation properties of hundreds of implanted peripheral nerve electrodes, allowing for electrode and parameter selection for neuroprosthetic applications.

  14. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  15. Novel screen printed electrode set for routine EEG recordings in patients with altered mental status.

    Science.gov (United States)

    Myllymaa, Sami; Lepola, Pasi; Hukkanen, Taina; Oun, Andre; Mervaala, Esa; Toyras, Juha; Lappalainen, Reijo; Myllymaa, Katja

    2013-01-01

    There is a growing need for an easy to use screening tool for the assessment of brain's electrical function in patients with altered mental status (AMS). The purpose of this study is to give a brief overview of the state-of-the-art in electrode technology, and to present a novel sub-hairline electrode set developed in our research group. Screen-printing technology was utilized to construct the electrode set consisting of ten electroencephalography (EEG) electrodes, two electrooculography (EOG) electrodes, two ground electrodes and two reference electrodes. Electrical characteristics of hydrogel-coated silver ink electrodes were found adequate for clinical EEG recordings as assessed by electrical impedance spectroscopy (EIS). The skin-electrode impedances remain stable and low enough at least two days enabling high-quality long-term recordings. Due to the proper material selection, thin ink layers and detachable zero insertion force (ZIF) - connector, electrode was observed to be CT- and MRI-compatible allowing imaging without removing the electrodes. Pilot EEG recordings gave very promising results and an on-going clinical trial with larger number of patients will show the true feasibility of this approach.

  16. Fabrication and electrochemical behavior of single-walled carbon nanotube/graphite-based electrode

    International Nuclear Information System (INIS)

    Moghaddam, Abdolmajid Bayandori; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Razavi, Taherehsadat; Riahi, Siavash; Rezaei-Zarchi, Saeed; Norouzi, Parviz

    2009-01-01

    An electrochemical method for determining the dihydroxybenzene derivatives on glassy carbon (GC) has been developed. In this method, the performance of a single-walled carbon nanotube (SWCNT)/graphite-based electrode, prepared by mixing SWCNTs and graphite powder, was described. The resulting electrode shows an excellent behavior for redox of 3,4-dihydroxybenzoic acid (DBA). SWCNT/graphite-based electrode presents a significant decrease in the overvoltage for DBA oxidation as well as a dramatic improvement in the reversibility of DBA redox behavior in comparison with graphite-based and glassy carbon (GC) electrodes. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) procedures performed for used SWCNTs

  17. High Speed, Low Cost Fabrication of Gas Diffusion Electrodes for Membrane Electrode Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    DeCastro, Emory S.; Tsou, Yu-Min; Liu, Zhenyu

    2013-09-20

    Fabrication of membrane electrode assemblies (MEAs) depends on creating inks or pastes of catalyst and binder, and applying this suspension to either the membrane (catalyst coated membrane) or gas diffusion media (gas diffusion electrode) and respectively laminating either gas diffusion media or gas diffusion electrodes (GDEs) to the membrane. One barrier to cost effective fabrication for either of these approaches is the development of stable and consistent suspensions. This program investigated the fundamental forces that destabilize the suspensions and developed innovative approaches to create new, highly stable formulations. These more concentrated formulations needed fewer application passes, could be coated over longer and wider substrates, and resulted in significantly lower coating defects. In March of 2012 BASF Fuel Cell released a new high temperature product based on these advances, whereby our customers received higher performing, more uniform MEAs resulting in higher stack build yields. Furthermore, these new materials resulted in an “instant” increase in capacity due to higher product yields and material throughput. Although not part of the original scope of this program, these new formulations have also led us to materials that demonstrate equivalent performance with 30% less precious metal in the anode. This program has achieved two key milestones in DOE’s Manufacturing R&D program: demonstration of processes for direct coating of electrodes and continuous in-line measurement for component fabrication.

  18. Transparent Electrodes for Efficient Optoelectronics

    KAUST Repository

    Morales-Masis, Monica

    2017-03-30

    With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

  19. Transparent Electrodes for Efficient Optoelectronics

    KAUST Repository

    Morales-Masis, Monica; De Wolf, Stefaan; Woods-Robinson, Rachel; Ager, Joel W.; Ballif, Christophe

    2017-01-01

    With the development of new generations of optoelectronic devices that combine high performance and novel functionalities (e.g., flexibility/bendability, adaptability, semi or full transparency), several classes of transparent electrodes have been developed in recent years. These range from optimized transparent conductive oxides (TCOs), which are historically the most commonly used transparent electrodes, to new electrodes made from nano- and 2D materials (e.g., metal nanowire networks and graphene), and to hybrid electrodes that integrate TCOs or dielectrics with nanowires, metal grids, or ultrathin metal films. Here, the most relevant transparent electrodes developed to date are introduced, their fundamental properties are described, and their materials are classified according to specific application requirements in high efficiency solar cells and flexible organic light-emitting diodes (OLEDs). This information serves as a guideline for selecting and developing appropriate transparent electrodes according to intended application requirements and functionality.

  20. On dynamics of electric spark machining of pieces with the system of non-fixed electrod-tools

    International Nuclear Information System (INIS)

    Timoshenko, B.I.; Morozenko, V.N.

    1976-01-01

    Processing of bodies of revolution by a system of loose electrode-instruments freely resting upon the detail was considered. In this dynamic system correlations were found between the electrode-instrument mass, the angular velocity of the detail, the interelectrode space and the mechanic pulse value which agitated the oscillations of the electrode providing for the most efficient electro-spark treatment. A scheme of the forces acting on the electrode-instrument during the process was presented. An expression was obtained describing the optimum dependence between the oscillation system parametres, and an expression for the maximum number of discharges during an oscillation period of the electrode-inctrument [ru

  1. Electrode for disintegrating metallic material

    International Nuclear Information System (INIS)

    Persang, J.C.

    1985-01-01

    A graphite electrode is provided for disintegrating and removing metallic material from a workpiece, e.g., such as portions of a nuclear reactor to be repaired while in an underwater and/or radioactive environment. The electrode is provided with a plurality of openings extending outwardly, and a manifold for supplying a mixture of water and compressed gas to be discharged through the openings for sweeping away the disintegrated metallic material during use of the electrode

  2. Portable dual field gradient force multichannel flow cytometer device with a dual wavelength low noise detection scheme

    Science.gov (United States)

    James, Conrad D; Galambos, Paul C; Derzon, Mark S; Graf, Darin C; Pohl, Kenneth R; Bourdon, Chris J

    2012-10-23

    Systems and methods for combining dielectrophoresis, magnetic forces, and hydrodynamic forces to manipulate particles in channels formed on top of an electrode substrate are discussed. A magnet placed in contact under the electrode substrate while particles are flowing within the channel above the electrode substrate allows these three forces to be balanced when the system is in operation. An optical detection scheme using near-confocal microscopy for simultaneously detecting two wavelengths of light emitted from the flowing particles is also discussed.

  3. 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

  4. Field testing of sulphide electrodes

    International Nuclear Information System (INIS)

    Singh, P.R.; Gaonkar, K.B.; Gadiyar, H.S.

    1993-01-01

    Sulphide ion selective electrodes have been developed at BARC, for determination of Ag + and S - ions directly and Cl - and CN - ions indirectly. The electrodes were tested for their use in sulphide environments in the EAD (Effluent After Dilution) stream at the Heavy Water Plant, Kota. The electrodes are suitable in the concentration range of 16000 ppm to 0.002 ppm, with a slope of 29-31 mV per decade change in the sulphide ion concentration. The response time is less than 10 seconds. These electrodes are reliable for continuous on-line use for a long period. (author). 7 refs., 11 figs., 1 tab

  5. Coated carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng [Newton, MA; Wen, Jian [Newton, MA; Chen, Jinghua [Chestnut Hill, MA; Huang, Zhongping [Belmont, MA; Wang, Dezhi [Wellesley, MA

    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.

  6. Microbial electrode sensor for alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Hikuma, M [Ajinomoto Co., Inc., Kawasaki, Japan; Kubo, T; Yasuda, T; Karube, I; Suzuki, S

    1979-10-01

    A microbial electrode consisting of immobilized microorganisms, a gas permeable Teflon membrane, and an oxygen electrode was prepared for the continuous determination of methyl and ethyl alcohols. Immobilized Trichosporon brassicae was employed for a microbial electrode sensor for ethyl alcohol. When a sample solution containing ethyl alcohol was injected into a microbial electrode system, the current of the electrode decreased markedly with time until a steady state was reached. The response time was within 10 min by the steady state method and within 6 min by the pulse method. A linear relationship was observed between the current decrease and the concentration of ethyl alcohol below 22.5 mg/liter. The current was reproducible within +- 6% of the relative error when a sample solution containing 16.5 mg/liter ethyl alcohol. The standard deviation was 0.5 mg/liter in 40 experiments. The selectivity of the microbial electrode sensor for ethyl alcohol was satisfactory. The microbial electrode sensor was applied to a fermentation broth of yeasts and satisfactory comparative results were obtained (correlation coefficient 0.98). The current output of the microbial electrode sensor was almost constant for more than three weeks and 2100 assays. A microbial electrode sensor using immobilized bacteria for methyl alcohol was also described.

  7. Co-axial electrodes gun characteristics

    International Nuclear Information System (INIS)

    Masoud, M.M.; Soliman, H.M.

    1981-01-01

    A coaxial electrodes gun is constructed with inner electrode diameter of 3.2 cm; outer electrode diameter of 6.6 cm and length of 25 cm it is connected to a condenser bank which delivers 4 K joule stored energy. The maximum power of the discharge is equal to 4.5x10 4 K watt; for 5 KV charging voltage. The inductance showed two main peak values of 0.257μH and 0.27μH. Theoretical calculations using one-dimension-single fluid model is μ sed, which shows that the maximum acceleration is at 0.5 sec, and the gas breakdown takes place at the gun breech; at the start of the discharge, will leave the gun after 1.625μ sec, also the drift velocity, the force and the magnetic field are given. The measured results show quite reasonable agreement with the calculations for most of the results, and the position of the plasma sheath inside the gun slightly deviated from the theoretical calculations due to viscosity and wall interaction, as well as other parameters which did not be take into consideration. The plasma current density of the sheath has its maximum value at Z=18 cm, the plasma will leave the coaxial source after 1.5μ sec, from the start of the discharge, which conferms with the theoretical model. Resistance of the gas between the electrodes, changes with time according to the particle injected from this source, and the maximum efficiency of the installation for charging voltage 5kV and pressure 80μ Hg is at approx.=10μ sec and 20.5μ sec

  8. Lithium alloy negative electrodes

    Science.gov (United States)

    Huggins, Robert A.

    The 1996 announcement by Fuji Photo Film of the development of lithium batteries containing convertible metal oxides has caused a great deal of renewed interest in lithium alloys as alternative materials for use in the negative electrode of rechargeable lithium cells. The earlier work on lithium alloys, both at elevated and ambient temperatures is briefly reviewed. Basic principles relating thermodynamics, phase diagrams and electrochemical properties under near-equilibrium conditions are discussed, with the Li-Sn system as an example. Second-phase nucleation, and its hindrance under dynamic conditions plays an important role in determining deviations from equilibrium behavior. Two general types of composite microstructure electrodes, those with a mixed-conducting matrix, and those with a solid electrolyte matrix, are discussed. The Li-Sn-Si system at elevated temperatures, and the Li-Sn-Cd at ambient temperatures are shown to be examples of mixed-conducting matrix microstructures. The convertible oxides are an example of the solid electrolyte matrix type. Although the reversible capacity can be very large in this case, the first cycle irreversible capacity required to convert the oxides to alloys may be a significant handicap.

  9. Crystallic silver amalgam--a novel electrode material.

    Science.gov (United States)

    Danhel, Ales; Mansfeldova, Vera; Janda, Pavel; Vyskocil, Vlastimil; Barek, Jiri

    2011-09-21

    A crystallic silver amalgam was found to be a suitable working electrode material for voltammetric determination of electrochemically reducible organic nitro-compounds. Optimum conditions for crystal growth were found, the crystal surface was investigated by atomic force microscopy in tapping mode and single crystals were used for the preparation of quasi-cylindrical single crystal silver amalgam electrode (CAgAE). An electrochemical behavior of this alternative electrode material was investigated in aqueous media by direct current voltammetry, cyclic voltammetry (CV), differential pulse voltammetry (DPV) and adsorptive stripping voltammetry (AdSV) using 4-nitrophenol as a model compound. Applicable potential windows of the CAgAE were found comparable with those obtained at a hanging mercury drop electrode, providing high hydrogen overpotential, and polished silver solid amalgam electrode. Thanks to the smooth single crystal electrode surface, the effect of the passivation is not too pronounced, direct DPV determination of 100 μmol l(-1) of 4-nitrophenol at CAgAEs in 0.2 mol l(-1) acetate buffer pH 4.8 provides a RSD around 1.5% (n = 15). DPV calibration curves of 4-nitrophenol are linear in the whole concentration range 1-100 μmol l(-1) with a limit of quantification of 1.5 μmol l(-1). The attempt to increase sensitivity by application of AdSV was not successful. The mechanism of 4-nitrophenol reduction at CAgAE was investigated by CV.

  10. 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...

  11. Advantages of using Ti-mesh type electrodes for flexible dye-sensitized solar cells

    International Nuclear Information System (INIS)

    He Weizhen; Kim, Hyung-Kook; Hwang, Yoon-Hwae; Qiu Jijun; Zhuge Fuwei; Li Xiaomin; Lee, Jae-Ho; Kim, Yang-Do

    2012-01-01

    We used Ti meshes for both the photoanodes and counter electrodes of dye-sensitized solar cells (DSSCs) to improve the flexibility and conductivity of the electrodes. These mesh type electrodes showed good transparency and high bendability when subjected to an external force. We demonstrated the advantages of cells using such electrodes compared to traditional transparent conducting oxide based electrodes and back side illuminated DSSCs, such as low sheet resistance, elevated photo-induced current and enhanced sunlight utilization. Nanotube layers of different thicknesses were investigated to determine their effect on the photovoltaic parameters of the cell. The overall efficiency of the best cells was approximately 5.3% under standard air mass 1.5 global (AM 1.5 G) solar conditions. Furthermore, the DSSCs showed an efficiency of approximately 3.15% due to the all Ti-mesh type electrodes even after illumination from the back side. (paper)

  12. Control of Bouncing in MEMS Switches Using Double Electrodes

    KAUST Repository

    Abdul Rahim, Farhan

    2016-08-09

    This paper presents a novel way of controlling the bouncing phenomenon commonly present in the Radio Frequency Microelectromechanical Systems (RF MEMS) switches using a double-electrode configuration. The paper discusses modeling bouncing using both lumped parameter and beam models. The simulations of bouncing and its control are discussed. Comparison between the new proposed method and other available control techniques is also made. The Galerkin method is applied on the beam model accounting for the nonlinear electrostatic force, squeeze film damping, and surface contact effect. The results indicate that it is possible to reduce bouncing and hence beam degradation, by the use of double electrodes.

  13. Different forces

    CERN Multimedia

    1982-01-01

    The different forces, together with a pictorial analogy of how the exchange of particles works. The table lists the relative strength of the couplings, the quanta associated with the force fields and the bodies or phenomena in which they have a dominant role.

  14. Labor Force

    Science.gov (United States)

    Occupational Outlook Quarterly, 2010

    2010-01-01

    The labor force is the number of people aged 16 or older who are either working or looking for work. It does not include active-duty military personnel or institutionalized people, such as prison inmates. Quantifying this total supply of labor is a way of determining how big the economy can get. Labor force participation rates vary significantly…

  15. Catoptric electrodes: transparent metal electrodes using shaped surfaces.

    Science.gov (United States)

    Kik, Pieter G

    2014-09-01

    An optical electrode design is presented that theoretically allows 100% optical transmission through an interdigitated metallic electrode at 50% metal areal coverage. This is achieved by redirection of light incident on embedded metal electrode lines to an angle beyond that required for total internal reflection. Full-field electromagnetic simulations using realistic material parameters demonstrate 84% frequency-averaged transmission for unpolarized illumination across the entire visible spectral range using a silver interdigitated electrode at 50% areal coverage. The redirection is achieved through specular reflection, making it nonresonant and arbitrarily broadband, provided the electrode width exceeds the optical wavelength. These findings could significantly improve the performance of photovoltaic devices and optical detectors that require high-conductivity top contacts.

  16. 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

  17. EDM Electrode for Internal Grooves

    Science.gov (United States)

    Ramani, V.; Werner, A.

    1985-01-01

    Electroerosive process inexpensive alternative to broaching. Hollow brass electrodes, soldered at one end to stainless-steel holding ring, held in grooves in mandrel. These electrodes used to machine grooves electrically in stainless-steel tube three-eights inch (9.5 millimeters) in diameter. Tool used on tubes already in place in equipment.

  18. 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.

  19. Surface-modified electrodes (SME)

    NARCIS (Netherlands)

    Schreurs, J.P.G.M.; Barendrecht, E.

    1984-01-01

    This review deals with the literature (covered up to August 1983), the characterization and the applications of Surface-Modified Electrodes (SME). As a special class of SME's, the Enzyme-Modified Electrode (EME) is introduced. Three types of modification procedures are distinguished; i.e. covalent

  20. Storage-battery electrodes. [preparation

    Energy Technology Data Exchange (ETDEWEB)

    1961-12-29

    Two incompatible thermoplastic resins are mixed with a powdered electrochemical active substance. The substance may be, for example, an oxide of cadmium, iron, lead, or zinc or nickel hydroxide. After the mixture is shaped into elements which are inserted into conducting sheaths for an electrode, the one resin is washed out to form a porous electrode. (RWR)

  1. Electrochemical photovoltaic cells and electrodes

    Science.gov (United States)

    Skotheim, Terje A.

    1984-01-01

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

  2. Improved photovoltaic cells and electrodes

    Science.gov (United States)

    Skotheim, T.A.

    1983-06-29

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

  3. Multi electrode semiconductors detectors

    CERN Document Server

    Amendolia, S R; Bertolucci, Ennio; Bosisio, L; Bradaschia, C; Budinich, M; Fidecaro, F; Foà, L; Focardi, E; Giazotto, A; Giorgi, M A; Marrocchesi, P S; Menzione, A; Ristori, L; Rolandi, Luigi; Scribano, A; Stefanini, A; Vincelli, M L

    1981-01-01

    Detectors with very high space resolution have been built in this laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (3 refs).

  4. Multi electrode semiconductor detectors

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Batignani, G.; Bertolucci, E.; Bosisio, L.; Budinich, M.; Bradaschia, C.; Fidecaro, F.; Foa, L.; Focardi, E.; Giazotto, A.; Giorgi, M.A.; Marrocchesi, P.S.; Menzione, A.; Ristori, L.; Rolandi, L.; Scribano, A.; Stefanini, A.; Vincelli, M.L.

    1981-01-01

    Detectors with very high space resolution have been built in the laboratory and tested at CERN in order to investigate their possible use in high energy physics experiments. These detectors consist of thin layers of silicon crystals acting as ionization chambers. Thin electrodes, structured in strips or in more fancy shapes are applied to their surfaces by metal coating. The space resolution which could be reached is of the order of a few microns. An interesting feature of these solid state detectors is that they can work under very high or low external pressure or at very low temperature. The use of these detectors would strongly reduce the dimensions and the cost of high energy experiments. (Auth.)

  5. Adsorption at electrodes

    International Nuclear Information System (INIS)

    Hubbard, A.T.; Ping Gao

    1991-01-01

    Surface electrochemical studies are described and summarized in which atomic, ionic or molecular layers were allowed to form from aqueous solutions at well-defined Pt(111) surfaces. The resulting adsorbed layers were chemisorbed in most cases and stable in vacuum, permitting identification and quantitation by Auger spectroscopy, EELS, LEED and electrochemistry. Adsorbed atomic, ionic, or molecular layers formed at metal-solution interfaces frequently display long-range order. Molecular properties of the adsorbed layers correlate with their electrochemical properties. The molecular orientation of organic adsorbates was deduced from packing density measurements, supplemented with vibrational spectra. Interfacial variables such as electrode potential have a strong influence on interfacial structure along with the nature and mode of surface attachment of adsorbates. The angular distribution of Auger electron emission from metal single crystals and atomic adsorbed layers has proved to be useful for direct imaging of surface crystal and interfacial structure. (author). 14 refs, 11 figs

  6. Gel electrolytes and electrodes

    Science.gov (United States)

    Fleischmann, Sven; Bunte, Christine; Mikhaylik, Yuriy V.; Viner, Veronika G.

    2017-09-05

    Gel electrolytes, especially gel electrolytes for electrochemical cells, are generally described. In some embodiments, the gel electrolyte layers comprise components a) to c). Component a) may be at least one layer of at least one polymer comprising polymerized units of: a1) at least one monomer containing an ethylenically unsaturated unit and an amido group and a2) at least one crosslinker. Component b) may be at least one conducting salt and component c) may be at least one solvent. Electrodes may comprise the components a), d) and e), wherein component a) may be at least one layer of at least one polymer as described herein. Component d) may be at least one electroactive layer and component e) may be at least one ceramic layer. Furthermore, electrochemical cells comprising component a) which may be at least one layer of at least one polymer as described herein, are also provided.

  7. Electrode for a lithium cell

    Science.gov (United States)

    Thackeray, Michael M [Naperville, IL; Vaughey, John T [Elmhurst, IL; Dees, Dennis W [Downers Grove, IL

    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.

  8. ELECTROD FLUOR-SELECTIV

    Directory of Open Access Journals (Sweden)

    Mariana DÎRU

    2018-03-01

    Full Text Available A fost preparat un senzor anionic specific, bazat pe pivalatul trinuclear al cromului(III ca material electro­activ încorporat în membrana PVC plastifiată. Senzorul prezintă răspuns Nernstian (55,78 mV/decadă în intervalul de concentrație 10-1-10-4 mol/L cu limita de detecție 2,0∙10-5 mol/L pentru anionul fluorură. Domeniul optim de pH de funcţionare a electrodului asamblat este ˃5. Senzorul dat are un timp de răspuns de 30-60 s și reproductibilitatea rezultatelor se menține timp de 3 luni. Coeficienții potențiometrici ai selectivității au fost determinați prin metoda soluțiilor separate. A fost realizată aplicarea acestor electrozi la analiza pastei de dinți ce conține fluorură și rezultatele experimentale au fost comparate cu datele de pe prospect.FLUORIDE-SELECTIVE ELECTRODEA specific anionic sensor has been prepared, based on trinuclearchromium(III pivalate as sensing material incorpo­rated into the plasticized PVC-membrane. The sensor exhibited Nernstian response (55,78 mV/decade in the region between 10-1-10-4 mol/L with a detection limit of 2,0∙10-5 mol/L for fluoride. The working pH of the electrode was in the 5-6 range. The sensor has a response time 30-60 s and can be used for least 3 month. The potentiometric selectivity coefficients were determined by separate solution method. Application of these electrodes to the analysis of toothpaste containing fluoride has been realized and experimental results have been compared with the data on the prospectus.

  9. Capacitance enhancement via electrode patterning

    International Nuclear Information System (INIS)

    Ho, Tuan A.; Striolo, Alberto

    2013-01-01

    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

  10. Studies of pyrrole black electrodes as possible battery positive electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mengoli, G.; Musiani, M.M.; Fleischmann, M.; Pletcher, D.

    1984-05-01

    It is shown that a polypyrrole, pyrrole black, may be formed anodically in several aqueous acids. The polypyrrole film shows a redox couple at less positive potentials than that required to form the film and the charge associated with these reduction and oxidation processes together with their stabilty to cycling varies with the anion in solution and the potential where the polypyrrole is formed; over-oxidation of the film caused by taking its potential too positive has a particularly disadvantageous affect. In the acids HBr and HI, the polypyrrole films can act as a storage medium for Br/sub 2/ or I/sub 2/ so that they may be used as a substrate for a X/sub 2//X/sup -/ electrode. Such electrodes may be charge/discharge cycled and the pyrrole/Br/sub 2/ electrode shows promise as a battery positive electrode.

  11. Nanothorn electrodes for ionic polymer-metal composite artificial muscles.

    Science.gov (United States)

    Palmre, Viljar; Pugal, David; Kim, Kwang J; Leang, Kam K; Asaka, Kinji; Aabloo, Alvo

    2014-08-22

    Ionic polymer-metal composites (IPMCs) have recently received tremendous interest as soft biomimetic actuators and sensors in various bioengineering and human affinity applications, such as artificial muscles and actuators, aquatic propulsors, robotic end-effectors, and active catheters. Main challenges in developing biomimetic actuators are the attainment of high strain and actuation force at low operating voltage. Here we first report a nanostructured electrode surface design for IPMC comprising platinum nanothorn assemblies with multiple sharp tips. The newly developed actuator with the nanostructured electrodes shows a new way to achieve highly enhanced electromechanical performance over existing flat-surfaced electrodes. We demonstrate that the formation and growth of the nanothorn assemblies at the electrode interface lead to a dramatic improvement (3- to 5-fold increase) in both actuation range and blocking force at low driving voltage (1-3 V). These advances are related to the highly capacitive properties of nanothorn assemblies, increasing significantly the charge transport during the actuation process.

  12. Developing Barbed Microtip-Based Electrode Arrays for Biopotential Measurement

    Directory of Open Access Journals (Sweden)

    Li-Sheng Hsu

    2014-07-01

    Full Text Available This study involved fabricating barbed microtip-based electrode arrays by using silicon wet etching. KOH anisotropic wet etching was employed to form a standard pyramidal microtip array and HF/HNO3 isotropic etching was used to fabricate barbs on these microtips. To improve the electrical conductance between the tip array on the front side of the wafer and the electrical contact on the back side, a through-silicon via was created during the wet etching process. The experimental results show that the forces required to detach the barbed microtip arrays from human skin, a polydimethylsiloxane (PDMS polymer, and a polyvinylchloride (PVC film were larger compared with those required to detach microtip arrays that lacked barbs. The impedances of the skin-electrode interface were measured and the performance levels of the proposed dry electrode were characterized. Electrode prototypes that employed the proposed tip arrays were implemented. Electroencephalogram (EEG and electrocardiography (ECG recordings using these electrode prototypes were also demonstrated.

  13. Electrochemical Oxidation of Cyanide Using Platinized Ti Electrodes

    Directory of Open Access Journals (Sweden)

    Aušra VALIŪNIENĖ

    2013-12-01

    Full Text Available The cyanide-containing effluents are dangerous ecological hazards and must be treated before discharging into the environment. Anodic oxidation is one of the best ways to degrade cyanides. Pt anodes as the most efficient material for the cyanide electrochemical degradation are widely used. However, these electrodes are too expensive for industrial purposes. In this work Ti electrodes covered with nano-sized Pt particle layer were prepared and used for the anodic oxidation of cyanide ions. Surface images of Ti electrodes and Ti electrodes covered with different thickness layer of Pt were compared and characterized by the atomic force microscopy (AFM. The products formed in the solution during the CN- ions electrooxidation were examined by the Raman spectroscopy. An electrochemical Fast Fourier transformation (FFT impedance spectroscopy was used to estimate the parameters that reflect real surface roughness of Pt-modified Ti electrodes.DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2514

  14. Immobilization of olfactory receptors onto gold electrodes for electrical biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Casuso, Ignacio [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain)], E-mail: icasuso@pcb.ub.es; Pla-Roca, Mateu [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain); Gomila, Gabriel [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain)], E-mail: ggomila@pcb.ub.es; Samitier, Josep [Departament d' Electronica, Universitat de Barcelona, Laboratori de Nanobioenginyeria-IBEC, Parc Cientific de Barcelona, C/Josep Samitier 1-5, Barcelona (Spain); Minic, Jasmina; Persuy, Marie A.; Salesse, Roland; Pajot-Augy, Edith [INRA, Neurobiologie de l' Olfaction et de la Prise Alimentaire, Equipe Recepteurs et Communication Chimique, Domaine de Vilvert, Jouy en Josas Cedex (France)

    2008-07-01

    We investigate the immobilization of native nanovesicles containing functional olfactory receptors onto gold electrodes by means of atomic force microscopy in liquid. We show that nanovesicles can be adsorbed without disrupting them presenting sizes once immobilized ranging from 50 nm to 200 nm in diameter. The size of the nanovesicles shows no dependence on the electrode hydrophobicity being constant in a height/width ratio close to 1:3. Nevertheless, electrode hydrophobicity does affect the surface coverage, the surface coverage is five times higher in hydrophilic electrodes than on hydrophobic ones. Surface coverage is also affected by nanovesicles dimensions in suspension, the size homogenization to around 50 nm yields a further five fold increment in surface coverage achieving a coverage of about 50% close to the hard spheres jamming limit (54.7%). A single layer of nanovesicles is always formed with no particle overlap. Present results provide insights into the immobilization on electrodes of olfactory receptors for further olfactory electrical biosensor development.

  15. 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.

  16. Three-electrode self-actuating self-sensing quartz cantilever: design, analysis, and experimental verification.

    Science.gov (United States)

    Chen, C Julian; Schwarz, Alex; Wiesendanger, Roland; Horn, Oliver; Müller, Jörg

    2010-05-01

    We present a novel quartz cantilever for frequency-modulation atomic force microscopy (FM-AFM) which has three electrodes: an actuating electrode, a sensing electrode, and a ground electrode. By applying an ac signal on the actuating electrode, the cantilever is set to vibrate. If the frequency of actuation voltage closely matches one of the characteristic frequencies of the cantilever, a sharp resonance should be observed. The vibration of the cantilever in turn generates a current on the sensing electrode. The arrangement of the electrodes is such that the cross-talk capacitance between the actuating electrode and the sensing electrode is less than 10(-16) F, thus the direct coupling is negligible. To verify the principle, a number of samples were made. Direct measurements with a Nanosurf easyPPL controller and detector showed that for each cantilever, one or more vibrational modes can be excited and detected. Using classical theory of elasticity, it is shown that such novel cantilevers with proper dimensions can provide optimized performance and sensitivity in FM-AFM with very simple electronics.

  17. Nuclear forces

    International Nuclear Information System (INIS)

    Holinde, K.

    1990-01-01

    In this paper the present status of the meson theory of nuclear forces is reviewed. After some introductory remarks about the relevance of the meson exchange concept in the era of QCD and the empirical features of the NN interaction, the exciting history of nuclear forces is briefly outlined. In the main part, the author gives the basic physical ideas and sketch the derivation of the one-boson-exchange model of the nuclear force, in the Feynman approach. Secondly we describe, in a qualitative way, various necessary extensions, leading to the Bonn model of the N interaction. Finally, points to some interesting pen questions connected with the extended quark structure of the hadrons, which are topics of current research activity

  18. Fractals in several electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chunyong, E-mail: zhangchy@njau.edu.cn [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Suzhou Key Laboratory of Environment and Biosafety, Suzhou Academy of Southeast University, Dushuhu lake higher education town, Suzhou 215123 (China); Wu, Jingyu [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Fu, Degang [Suzhou Key Laboratory of Environment and Biosafety, Suzhou Academy of Southeast University, Dushuhu lake higher education town, Suzhou 215123 (China); State Key Laboratory of Bioelectronics, Southeast University, Nanjing 210096 (China)

    2014-09-15

    Highlights: • Fractal geometry was employed to characterize three important electrode materials. • The surfaces of all studied electrodes were proved to be very rough. • The fractal dimensions of BDD and ACF were scale dependent. • MMO film was more uniform than BDD and ACF in terms of fractal structures. - Abstract: In the present paper, the fractal properties of boron-doped diamond (BDD), mixed metal oxide (MMO) and activated carbon fiber (ACF) electrode have been studied by SEM imaging at different scales. Three materials are self-similar with mean fractal dimension in the range of 2.6–2.8, confirming that they all exhibit very rough surfaces. Specifically, it is found that MMO film is more uniform in terms of fractal structure than BDD and ACF. As a result, the intriguing characteristics make these electrodes as ideal candidates for high-performance decontamination processes.

  19. Electrode materials for rechargeable batteries

    Science.gov (United States)

    Abouimrane, Ali; Amine, Khalil

    2015-04-14

    Selenium or selenium-containing compounds may be used as electroactive materials in electrodes or electrochemical devices. The selenium or selenium-containing compound is mixed with a carbon material.

  20. Parameter Optimization and Electrode Improvement of Rotary Stepper Micromotor

    Science.gov (United States)

    Sone, Junji; Mizuma, Toshinari; Mochizuki, Shunsuke; Sarajlic, Edin; Yamahata, Christophe; Fujita, Hiroyuki

    We developed a three-phase electrostatic stepper micromotor and performed a numerical simulation to improve its performance for practical use and to optimize its design. We conducted its circuit simulation by simplifying its structure, and the effect of springback force generated by supported mechanism using flexures was considered. And we considered new improvement method for electrodes. This improvement and other parameter optimizations achieved the low voltage drive of micromotor.

  1. Composite Electrodes for Electrochemical Supercapacitors

    OpenAIRE

    Li, Jun; Yang, QuanMin; Zhitomirsky, Igor

    2010-01-01

    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 to...

  2. Seismic responses of unanchored electrode storage fixtures

    International Nuclear Information System (INIS)

    Ting-shu Wu; Blomquist, C.A.; Haupt, H.J.; Herceg, J.E.

    1993-01-01

    Two anchored electrode storage fixtures will be installed in the process cell of the Integral Fast Reactor's Fuel Cycle Facility at ANL-W in Idaho. In addition to the concerns for structural integrity, the potential for uplifting and tipping of the fixtures during the design basis earthquake must also be examined. In the analysis, a response-spectrum method was employed to investigate tipping, while a static approach was used for the structural-integrity evaluations. The results show that the combined stresses from seismic and other loads are within the allowables permitted by the design codes. The overall vertical seismic reaction forces at the leveling pads are compressive, implying that the fixtures will remain in contact with the floor. No uplifting or tipping of the fixture will occur during the design basis earthquake

  3. Transition of poloidal viscosity by electrode biasing in the Large Helical Device

    International Nuclear Information System (INIS)

    Kitajima, S.; Ishii, K.; Sato, Y.; Kanno, M.; Tachibana, J.; Okamoto, A.; Sasao, M.; Takahashi, H.; Masuzaki, S.; Shoji, M.; Ashikawa, N.; Tokitani, M.; Yokoyama, M.; Suzuki, Y.; Satake, S.; Ido, T.; Shimizu, A.; Suzuki, C.; Inagaki, S.; Takayama, M.

    2013-01-01

    Electrode biasing experiments were carried out in various magnetic configurations on the Large Helical Device (LHD). The transitions of poloidal viscosity, which were accompanied with bifurcation phenomena characterized by a negative resistance in an electrode characteristic, were clearly observed on LHD by the electrode biasing. The critical external driving force required for transition was compared with the local maximum in ion viscosity, and the radial resistivity before the transition also compared with the expected value from a neoclassical theory. The critical driving force increased and the radial resistivity decreased with the major radius of the magnetic axis R ax going outwards. The configuration dependence of the transition condition and the radial resistivity qualitatively agreed with neoclassical theories. The radial electric field and the viscosity were also evaluated by the neoclassical transport code for a non-axisymmetric system, and estimated electrode voltage required for the transition, which was consistent with the experimental results. (paper)

  4. Amodiaquine polymeric membrane electrode.

    Science.gov (United States)

    Malongo, T Kimbeni; Blankert, B; Kambu, O; Amighi, K; Nsangu, J; Kauffmann, J-M

    2006-04-11

    The construction and electrochemical response characteristics of two types of poly(vinyl chloride) (PVC) membrane sensors for the determination of amodiaquine hydrochloride (ADQ.2HCl) are described. The sensing membrane comprised an ion-pair formed between the cationic drug and sodium tetraphenyl borate (NaTPB) or potassium tetrakis(4-chlorophenyl) borate (KTCPB) in a plasticized PVC matrix. Eight PVC membrane ion-selective electrodes were fabricated and studied. Several plasticizers were studied namely, dioctyl phthalate (DOP), 2-nitrophenyl octyl ether (NPOE), dioctyl phenylphosphonate (DOPP) and bis(2-ethylhexyl)adipate (EHA). The sensors display a fast, stable and near-Nernstian response over a relative wide ADQ concentration range (3.2 x 10(-6) to 2.0 x 10(-2) M), with slopes comprised between 28.5 and 31.4 mV dec(-1) in a pH range comprised between pH 3.7 and 5.5. The assay of amodiaquine hydrochloride in pharmaceutical dosage forms using one of the proposed sensors gave average recoveries of 104.3 and 99.9 with R.S.D. of 0.3 and 0.6% for tablets (Malaritab) and a reconstituted powder containing ADQ.2HCl, respectively. The sensor was also used for dissolution profile studies of two drug formulations. The sensor proved to have a good selectivity for ADQ.2HCl over some inorganic and organic compounds, however, berberine chloride interfered significantly. The results were validated by comparison with a spectrophotometric assay according to the USP pharmacopoeia.

  5. Voltammetry at micro-mesh electrodes

    Directory of Open Access Journals (Sweden)

    Wadhawan Jay D.

    2003-01-01

    Full Text Available The voltammetry at three micro-mesh electrodes is explored. It is found that at sufficiently short experimental durations, the micro-mesh working electrode first behaves as an ensemble of microband electrodes, then follows the behaviour anticipated for an array of diffusion-independent micro-ring electrodes of the same perimeter as individual grid-squares within the mesh. During prolonged electrolysis, the micro-mesh electrode follows that behaviour anticipated theoretically for a cubically-packed partially-blocked electrode. Application of the micro-mesh electrode for the electrochemical determination of carbon dioxide in DMSO electrolyte solutions is further illustrated.

  6. The kinetics of porous insertion electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Atlung, S; West, K [British Columbia Univ., Vancouver (Canada)

    1989-05-01

    The principles of porous electrodes are discussed as well as the discharge of the insertion compound, the working potential, transport in the electrolyte, the time dependence of the electrolyte concentration, and modeling of the porous electrode. The simulation of a TiS2 porous electrode and the composite insertion electrode are considered as well. The influence of electrode thickness and porosity in a typical porous TiS2 electrode is revealed. It is shown that the use of insertion compounds as battery electrodes is limited by the requirement that the inserted ion must be distributed in the interior of the insertion compound particle. 15 refs.

  7. 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.

  8. Extraction electrode geometry for a calutron

    International Nuclear Information System (INIS)

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

    1975-01-01

    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

  9. Novel parallel plate condenser for single particle electrostatic force measurements in atomic force microscope

    KAUST Repository

    Kwek, Jin Wang

    2011-07-01

    A combination of small parallel plate condenser with Indium Tin Oxide (ITO) glass slides as electrodes and an atomic force microscope (AFM) is used to characterize the electrostatic behavior of single glass bead microparticles (105-150 μm) glued to the AFM cantilever. This novel setup allows measurements of the electrostatic forces acting on a particle in an applied electrical field to be performed in ambient air conditions. By varying the position of the microparticle between the electrodes and the strength of the applied electric field, the relative contributions of the particle net charge, induced and image charges were investigated. When the microparticle is positioned in the middle of the electrodes, the force acting on the microparticle was linear with the applied electric field and proportional to the microparticle net charge. At distances close to the bottom electrode, the force follows a parabolic relationship with the applied electric field reflecting the contributions of induced and image charges. The method can be used for the rapid evaluation of the charging and polarizability properties of the microparticle as well as an alternative to the conventional Faraday\\'s pail technique. © 2011 Elsevier B.V.

  10. Electro-chemical deposition of zinc oxide nanostructures by using two electrodes

    Directory of Open Access Journals (Sweden)

    B. A. Taleatu

    2011-09-01

    Full Text Available One of the most viable ways to grow nanostructures is electro deposition. However, most electrodeposited samples are obtained by three-electrode electrochemical cell. We successfully use a much simpler two-electrode cell to grow different ZnO nanostructures from common chemical reagents. Concentration, pH of the electrolytes and growth parameters like potentials at the electrodes, are tailored to allow fast growth without complexity. Morphology and surface roughness are investigated by Scanning Electron and Air Force Microscopy (SEM and AFM respectively, crystal structure by X-Ray Diffraction measurements (XRD and ZnO stoichiometry by core level photoemission spectroscopy (XPS.

  11. Perovskites as electrodes of solid cells in sensitive elements of oxygen ion

    International Nuclear Information System (INIS)

    Gandurska, J.; Sniezynska, I.; Marek, A.; Szwagierczak, D.; Kulawik, J.

    1997-01-01

    The perovskite family comprises many compounds used in electronic applications. In this work perovskite materials based on LaCrO 3 were investigated, destined for electrodes of solid electrolyte oxygen sensors. lanthanum chromite powders modified by calcium, strontium and aluminium were prepared by the coprecipitation-calcination technique. The powders were examined using thermal analysis, x-ray diffraction analysis, scanning electron microscopy and transmission electron microscopy. Introductory studies of electromotive force of oxygen cells with yttria stabilized zirconia as solid electrolyte and perovskite-based electrodes proved that it is possible to replace expensive Pt electrodes by much cheaper perovskite ones. (author)

  12. 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...... materials as candidates for robust oxygen sensor electrodes. The present work focuses on characterising the electrochemical properties of a few electrode materials to understand which oxygen electrode processes are limiting for the response time of the sensor electrode. Three types of porous platinum......-Dansensor. The electrochemical properties of the electrodes were characterised by electrochemical impedance spectroscopy (EIS), and the structures were characterised by x-ray diffraction and electron microscopy. At an oxygen partial pressures of 0.2 bar, the response time of the sensor electrode was determined by oxygen...

  13. 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.

  14. 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.

  15. Composite Electrodes for Electrochemical Supercapacitors

    Science.gov (United States)

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

    2010-03-01

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

  16. The Stiffness Variation of a Micro-Ring Driven by a Traveling Piecewise-Electrode

    Directory of Open Access Journals (Sweden)

    Yingjie Li

    2014-09-01

    Full Text Available In the practice of electrostatically actuated micro devices; the electrostatic force is implemented by sequentially actuated piecewise-electrodes which result in a traveling distributed electrostatic force. However; such force was modeled as a traveling concentrated electrostatic force in literatures. This article; for the first time; presents an analytical study on the stiffness variation of microstructures driven by a traveling piecewise electrode. The analytical model is based on the theory of shallow shell and uniform electrical field. The traveling electrode not only applies electrostatic force on the circular-ring but also alters its dynamical characteristics via the negative electrostatic stiffness. It is known that; when a structure is subjected to a traveling constant force; its natural mode will be resonated as the traveling speed approaches certain critical speeds; and each natural mode refers to exactly one critical speed. However; for the case of a traveling electrostatic force; the number of critical speeds is more than that of the natural modes. This is due to the fact that the traveling electrostatic force makes the resonant frequencies of the forward and backward traveling waves of the circular-ring different. Furthermore; the resonance and stability can be independently controlled by the length of the traveling electrode; though the driving voltage and traveling speed of the electrostatic force alter the dynamics and stabilities of microstructures. This paper extends the fundamental insights into the electromechanical behavior of microstructures driven by electrostatic forces as well as the future development of MEMS/NEMS devices with electrostatic actuation and sensing.

  17. Nanofiber membrane-electrode-assembly and method of fabricating same

    Energy Technology Data Exchange (ETDEWEB)

    Pintauro, Peter N.; Ballengee, Jason; Brodt, Matthew

    2018-01-23

    In one aspect of the present invention, a method of fabricating a fuel cell membrane-electrode-assembly (MEA) having an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode electrode, includes fabricating each of the anode electrode, the cathode electrode, and the membrane separately by electrospinning; and placing the membrane between the anode electrode and the cathode electrode, and pressing then together to form the fuel cell MEA.

  18. Calcium-Antimony Alloys as Electrodes for Liquid Metal Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ouchi, T; Kim, H; Ning, XH; Sadoway, DR

    2014-08-08

    The performance of a calcium-antimony (Ca-Sb) alloy serving as the positive electrode in a Ca vertical bar vertical bar Sb liquid metal battery was investigated in an electrochemical cell, Ca(in Bi) vertical bar LiCl-NaCl-CaCl2 vertical bar Ca(in Sb). The equilibrium potential of the Ca-Sb electrode was found to lie on the interval, 1.2-0.95 V versus Ca, in good agreement with electromotive force (emf) measurements in the literature. During both alloying and dealloying of Ca at the Sb electrode, the charge transfer and mass transport at the interface are facile enough that the electrode potential varies linearly from 0.95 to 0.75 V vs Ca(s) as current density varies from 50 to 500 mA cm(-2). The discharge capacity of the Ca vertical bar vertical bar Sb cells increases as the operating temperature increases due to the higher solubility and diffusivity of Ca in Sb. The cell was successfully cycled with high coulombic efficiency (similar to 100%) and small fade rate (<0.01% cycle(-1)). These data combined with the favorable costs of these metals and salts make the Ca vertical bar vertical bar Sb liquid metal battery attractive for grid-scale energy storage. (C) The Author(s) 2014. Published by ECS. All rights reserved.

  19. Simulation study of dielectrophoretic assembly of nanowire between electrode pairs

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Quan, E-mail: taq3@pitt.edu; Lan, Fei; Jiang, Minlin [University of Pittsburgh, The Department of Electrical and Computer Engineering (United States); Wei, Fanan [Chinese Academy of Sciences, State Key Laboratory of Robotics, Shenyang Institute of Automation (China); Li, Guangyong, E-mail: gul6@pitt.edu [University of Pittsburgh, The Department of Electrical and Computer Engineering (United States)

    2015-07-15

    Dielectrophoresis (DEP) of rod-shaped nanostructures is attractive because of its exceptional capability to fabricate nanowire-based electronic devices. This efficient manipulation method, however, has a common side effect of assembling a certain number of nanowires at undesired positions. It is therefore essential to understand the underlying physics of DEP of nanowires in order to better guide the assembly. In this work, we propose theoretical methods to characterize the dielectrophoretic force and torque as well as the hydrodynamic drag force and torque on the nanowire (typical length: 10 μm). The trajectory of the nanowire is then simulated based on rigid body dynamics. The nanowire is predicted to either bridge the electrodes or attach on the surface of one electrode. A neighborhood in which the nanowire is more likely to bridge electrodes is found, which is conducive to successful assembly. The simulation study in this work provides us not only a better understanding of the underlying physics but also practical guidance on nanowire assembly by DEP.

  20. Characterisation of nano-interdigitated electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Skjolding, L H D; Ribayrol, A; Montelius, L [Division of Solid State Physics, Lund University, Box 118, SE-221 00 Lund (Sweden); Spegel, C [Department of Analytical Chemistry Lund University, Box 124, SE-221 00 Lund (Sweden); Emneus, J [MIC - Department of Micro and Nanotechnology, DTU - Building 345 East, DK-2800 Kgs. Lyngby (Denmark)], E-mail: lars_henrik.daehli_skjolding@ftf.lth.se

    2008-03-15

    Interdigitated electrodes made up of two individually addressable interdigitated comb-like electrode structures have frequently been suggested as ultra sensitive electrochemical biosensors. Since the signal enhancement effects due to cycling of the reduced and oxidized species are strongly dependent on the inter electrode distances, since the nature of the enhancement is due to overlying diffusion layers, interdigitated electrodes with an electrode separation of less then one micrometer are desired for maximum signal amplification. Fabrication of submicron structures can only be made by advanced lithography techniques. By use of electron beam lithography we have fabricated arrays of interdigitated electrodes with an electrode separation distance of 200 nm and an electrode finger width of likewise 200 nm. The entire electrode structure is 100 micrometre times 100 micrometre, and the active electrode area is dictated by the opening in the passivation layer, that is defined by UV lithography. Here we report measurements of redox cycling of ferrocyanide by coupled cyclic voltammograms, where the potential at one of the working electrodes are varied and either an oxidising or reducing potential is applied to the complimentary interdigitated electrode. The measurements show fast conversion and high collection efficiency round 87% as expected for nano-interdigitated electrodes.

  1. 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 of the elec...

  2. Anodized Steel Electrodes for Supercapacitors.

    Science.gov (United States)

    Sagu, Jagdeep S; Wijayantha, K G Upul; Bohm, Mallika; Bohm, Siva; Kumar Rout, Tapan

    2016-03-09

    Steel was anodized in 10 M NaOH to enhance its surface texture and internal surface area for application as an electrode in supercapacitors. A mechanism was proposed for the anodization process. Field-emission gun scanning electron microscopy (FEGSEM) studies of anodized steel revealed that it contains a highly porous sponge like structure ideal for supercapacitor electrodes. X-ray photoelectron spectroscopy (XPS) measurements showed that the surface of the anodized steel was Fe2O3, whereas X-ray diffraction (XRD) measurements indicated that the bulk remained as metallic Fe. The supercapacitor performance of the anodized steel was tested in 1 M NaOH and a capacitance of 18 mF cm(-2) was obtained. Cyclic voltammetry measurements showed that there was a large psueudocapacitive contribution which was due to oxidation of Fe to Fe(OH)2 and then further oxidation to FeOOH, and the respective reduction of these species back to metallic Fe. These redox processes were found to be remarkably reversible as the electrode showed no loss in capacitance after 10000 cycles. The results demonstrate that anodization of steel is a suitable method to produce high-surface-area electrodes for supercapacitors with excellent cycling lifetime.

  3. Advanced screening of electrode couples

    Science.gov (United States)

    Giner, J. D.; Cahill, K.

    1980-01-01

    The chromium (Cr(3+)/Cr(2+)) redox couple (electrolyte and electrode) was investigated to determine its suitability as negative electrode for the iron (Fe(3+)/Fe(2+))-chromium (Cr(3+)/Cr(2+)) redox flow battery. Literature search and laboratory investigation established that the solubility and stability of aqueous acidic solutions of chromium(3) chloride and chromium(2) chloride are sufficient for redox battery application. Four categories of electrode materials were tested; namely, metals and metalloid materials (elements and compounds), alloys, plated materials, and Teflon-bonded materials. In all, the relative performance of 26 candidate electrode materials was evaluated on the basis of slow scan rate linear sweep voltammetry in stirred solution. No single material tested gave both acceptable anodic an acceptable cathodic performance. However, the identification of lead as a good cathodic electrocatalyst and gold as a good anodic electrocatalyst led to the invention of the lead/gold combination electrocatalyst. This type of catalyst can be fabricated in several ways and appears to offer the advantages of each metal without the disadvantages associated with their use as single materials. This lead/gold electrocatalyst was tested by NASA-Lewis Research Center in complete, flowing, redox batteries comprising a stack of several cells. A large improvement in the battery's coulombic and energy efficiency was observed.

  4. Anharmonic 1D actuator model including electrostatic and Casimir forces with fractional damping perturbed by an external force

    Science.gov (United States)

    Mansoori Kermani, Maryam; Dehestani, Maryam

    2018-06-01

    We modeled a one-dimensional actuator including the Casimir and electrostatic forces perturbed by an external force with fractional damping. The movable electrode was assumed to oscillate by an anharmonic elastic force originated from Murrell-Mottram or Lippincott potential. The nonlinear equations have been solved via the Adomian decomposition method. The behavior of the displacement of the electrode from equilibrium position, its velocity and acceleration were described versus time. Also, the changes of the displacement have been investigated according to the frequency of the external force and the voltage of the electrostatic force. The convergence of the Adomian method and the effect of the orders of expansion on the displacement versus time, frequency, and voltage were discussed. The pull-in parameter was obtained and compared with the other models in the literature. This parameter was described versus the equilibrium position and anharmonicity constant.

  5. Anharmonic 1D actuator model including electrostatic and Casimir forces with fractional damping perturbed by an external force

    Science.gov (United States)

    Mansoori Kermani, Maryam; Dehestani, Maryam

    2018-03-01

    We modeled a one-dimensional actuator including the Casimir and electrostatic forces perturbed by an external force with fractional damping. The movable electrode was assumed to oscillate by an anharmonic elastic force originated from Murrell-Mottram or Lippincott potential. The nonlinear equations have been solved via the Adomian decomposition method. The behavior of the displacement of the electrode from equilibrium position, its velocity and acceleration were described versus time. Also, the changes of the displacement have been investigated according to the frequency of the external force and the voltage of the electrostatic force. The convergence of the Adomian method and the effect of the orders of expansion on the displacement versus time, frequency, and voltage were discussed. The pull-in parameter was obtained and compared with the other models in the literature. This parameter was described versus the equilibrium position and anharmonicity constant.

  6. Coriolis Force

    Science.gov (United States)

    Marciuc, Daly; Solschi, Viorel

    2017-04-01

    Understanding the Coriolis effect is essential for explaining the movement of air masses and ocean currents. The lesson we propose aims to familiarize students with the manifestation of the Coriolis effect. Students are guided to build, using the GeoGebra software, a simulation of the motion of a body, related to a rotating reference system. The mathematical expression of the Coriolis force is deduced, for particular cases, and the Foucault's pendulum is presented and explained. Students have the opportunity to deepen the subject, by developing materials related to topics such as: • Global Wind Pattern • Ocean Currents • Coriolis Effect in Long Range Shooting • Finding the latitude with a Foucault Pendulum

  7. Invisible force

    International Nuclear Information System (INIS)

    Panek, Richard

    2010-01-01

    Astronomers have compiled evidence that what we always thought of as the actual universe- all the planets, stars, galaxies and matter in space -represents a mere 4% of what's out there. The rest is dark: 23% is called dark matter, 73% dark energy. Scientists have ideas about what dark matter is, but hardly any understanding about dark energy. This has led to rethinking traditional physics and cosmology. Assuming the existence of dark matter and that the law of gravitation is universal, two teams of astrophysicists, from Lawrence Berkeley National Laboratory and the Australian National University, analysed the universe's growth and to their surprise both concluded that the universe expansion is not slowing but speeding up. If the dominant force of evolution isn't gravity what is it?

  8. Depositing bulk or micro-scale electrodes

    Science.gov (United States)

    Shah, Kedar G.; Pannu, Satinderpall S.; Tolosa, Vanessa; Tooker, Angela C.; Sheth, Heeral J.; Felix, Sarah H.; Delima, Terri L.

    2016-11-01

    Thicker electrodes are provided on microelectronic device using thermo-compression bonding. A thin-film electrical conducting layer forms electrical conduits and bulk depositing provides an electrode layer on the thin-film electrical conducting layer. An insulating polymer layer encapsulates the electrically thin-film electrical conducting layer and the electrode layer. Some of the insulating layer is removed to expose the electrode layer.

  9. Detection of EEG electrodes in brain volumes.

    Science.gov (United States)

    Graffigna, Juan P; Gómez, M Eugenia; Bustos, José J

    2010-01-01

    This paper presents a method to detect 128 EEG electrodes in image study and to merge with the Nuclear Magnetic Resonance volume for better diagnosis. First we propose three hypotheses to define a specific acquisition protocol in order to recognize the electrodes and to avoid distortions in the image. In the second instance we describe a method for segmenting the electrodes. Finally, registration is performed between volume of the electrodes and NMR.

  10. Recovery of fluoride ion selective electrode

    International Nuclear Information System (INIS)

    Monteiro, R.P.G.

    1988-01-01

    A recovery procedure of fluoride ion selective electrode based upon the body radiography of inactive electrode and introduction of suitable internal regeneration solution, is developed. The recovered electrode was tested in standard solutions of fluoride ions (10 sup5) to 10 -1M showing as good performance as the new one. The fluor determination by potentiometric measurements with selective electrode is used in nuclear fuel cycle for quality control of thorium and uranium mixed oxide pellets and pellets of uranium dioxides. (author) [pt

  11. Alkali metal ion battery with bimetallic electrode

    Science.gov (United States)

    Boysen, Dane A; Bradwell, David J; Jiang, Kai; Kim, Hojong; Ortiz, Luis A; Sadoway, Donald R; Tomaszowska, Alina A; Wei, Weifeng; Wang, Kangli

    2015-04-07

    Electrochemical cells having molten electrodes having an alkali metal provide receipt and delivery of power by transporting atoms of the alkali metal between electrode environments of disparate chemical potentials through an electrochemical pathway comprising a salt of the alkali metal. The chemical potential of the alkali metal is decreased when combined with one or more non-alkali metals, thus producing a voltage between an electrode comprising the molten the alkali metal and the electrode comprising the combined alkali/non-alkali metals.

  12. Ultralow-Power Electronic Trapping of Nanoparticles with Sub-10 nm Gold Nanogap Electrodes.

    Science.gov (United States)

    Barik, Avijit; Chen, Xiaoshu; Oh, Sang-Hyun

    2016-10-12

    We demonstrate nanogap electrodes for rapid, parallel, and ultralow-power trapping of nanoparticles. Our device pushes the limit of dielectrophoresis by shrinking the separation between gold electrodes to sub-10 nm, thereby creating strong trapping forces at biases as low as the 100 mV ranges. Using high-throughput atomic layer lithography, we manufacture sub-10 nm gaps between 0.8 mm long gold electrodes and pattern them into individually addressable parallel electronic traps. Unlike pointlike junctions made by electron-beam lithography or larger micron-gap electrodes that are used for conventional dielectrophoresis, our sub-10 nm gold nanogap electrodes provide strong trapping forces over a mm-scale trapping zone. Importantly, our technology solves the key challenges associated with traditional dielectrophoresis experiments, such as high voltages that cause heat generation, bubble formation, and unwanted electrochemical reactions. The strongly enhanced fields around the nanogap induce particle-transport speed exceeding 10 μm/s and enable the trapping of 30 nm polystyrene nanoparticles using an ultralow bias of 200 mV. We also demonstrate rapid electronic trapping of quantum dots and nanodiamond particles on arrays of parallel traps. Our sub-10 nm gold nanogap electrodes can be combined with plasmonic sensors or nanophotonic circuitry, and their low-power electronic operation can potentially enable high-density integration on a chip as well as portable biosensing.

  13. Photometric requirements for portable changeable message signs.

    Science.gov (United States)

    2001-09-01

    This project reviewed the performance of pchangeable message signs (PCMSs) and developed photometric standards to establish performance requirements. In addition, researchers developed photometric test methods and recommended them for use in evaluati...

  14. Minimizing electrode contamination in an electrochemical cell

    Science.gov (United States)

    Kim, Yu Seung; Zelenay, Piotr; Johnston, Christina

    2014-12-09

    An electrochemical cell assembly that is expected to prevent or at least minimize electrode contamination includes one or more getters that trap a component or components leached from a first electrode and prevents or at least minimizes them from contaminating a second electrode.

  15. 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.

  16. Corrosion behavior of a positive graphite electrode in vanadium redox flow battery

    International Nuclear Information System (INIS)

    Liu Huijun; Xu Qian; Yan Chuanwei; Qiao Yonglian

    2011-01-01

    Graphical abstract: The overpotential for gas evolution on positive graphite electrode decreases due to the functional groups of COOH and C=O introduced on the surface of graphite electrode during corrosion process, which can self-catalyze the oxidation of carbon atoms therefore, accelerates corrosion process. Highlights: → Initial potential for gas evolution is higher than 1.60 V vs SCE. → Factors affecting the graphite corrosion are investigated. → Functional groups of COOH and C=O introduced during corrosion process. → The groups can self-catalyze the oxidation of carbon atoms. - Abstract: The graphite plate is easily suffered from corosion because of CO 2 evolution when it acts as the positive electrode for vanadium redox flow battery. The aim is to obtain the initial potential for gas evolution on a positive graphite electrode in 2 mol dm -3 H 2 SO 4 + 2 mol dm -3 VOSO 4 solution. The effects of polarization potential, operating temperature and polarization time on extent of graphite corrosion are investigated by potentiodynamic and potentiostatic techniques. The surface characteristics of graphite electrode before and after corrosion are examined by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. The results show that the gas begins to evolve on the graphite electrode when the anodic polarization potential is higher than 1.60 V vs saturated calomel electrode at 20 deg. C. The CO 2 evolution on the graphite electrode can lead to intergranular corrosion of the graphite when the polarization potential reaches 1.75 V. In addition, the functional groups of COOH and C=O introduced on the surface of graphite electrode during corrosion can catalyze the formation of CO 2 , therefore, accelerates the corrosion rate of graphite electrode.

  17. Electrocatalytic reduction of nitrite on tetraruthenated metalloporphyrins/Nafion glassy carbon modified electrode

    Energy Technology Data Exchange (ETDEWEB)

    Calfuman, Karla [Facultad de Ciencias, Departamento de Quimica, Universidad de Chile, Las Palmeras 3425, Casilla 653, Nunoa, Santiago (Chile); Aguirre, Maria Jesus [Facultad de Quimica y Biologia, Departamento de Quimica de los Materiales, Universidad de Santiago de Chile, Santiago (Chile); Canete-Rosales, Paulina; Bollo, Soledad [Facultad de Ciencias Quimicas y Farmaceuticas, Departamento de Quimica Farmacologica y Toxicologica, Universidad de Chile, Santiago (Chile); Llusar, Rosa [Departamento de Quimica Fisica y Analitica, Universidad de Jaume I, Castellon (Spain); Isaacs, Mauricio, E-mail: misaacs@uchile.cl [Facultad de Ciencias, Departamento de Quimica, Universidad de Chile, Las Palmeras 3425, Casilla 653, Nunoa, Santiago (Chile)

    2011-10-01

    Highlights: > Preparation and characterization of modified electrodes with M(II) Tetraruthenated porphyrins onto a Nafion film. > The electrodes were characterized by SEM, TEM, AFM and SECM techniques. > The modified electrodes are active in the electrochemical reduction of nitrite at -660 mV vs Ag/AgCl. > GC/Nf/CoTRP modified electrode is more electrochemically active than their Ni and Zn analogues. - Abstract: This paper describes the electrochemical reduction of nitrite ion in neutral aqueous solution mediated by tetraruthenated metalloporphyrins (Co(II), Ni(II) and Zn(II)) electrostatically assembled onto a Nafion film previously adsorbed on glassy carbon or ITO electrodes. Scanning electron microscope (SEM-EDX) and transmission electron microscopy (TEM) results have shown that on ITO electrodes the macrocycles forms multiple layers with a disordered stacking orientation over the Nafion film occupying hydrophobic and hydrophilic sites in the polyelectrolyte. Atomic force microscopy (AFM) results demonstrated that the Nafion film is 35 nm thick and tetraruthenated metalloporphyrins layers 190 nm thick presenting a thin but compacted morphology. Scanning electrochemical microscopy (SECM) images shows that the Co(II) tetraruthenated porphyrins/Nf/GC modified electrode is more electrochemically active than their Ni and Zn analogues. These modified electrodes are able to reduce nitrite at -660 mV showing enhanced reduction current and a decrease in the required overpotential compared to bare glassy carbon electrode. Controlled potential electrolysis experiments verify the production of ammonia, hydrazine and hydroxylamine at potentials where reduction of solvent is plausible demonstrating some selectivity toward the nitrite ion. Rotating disc electrode voltammetry shows that the factor that governs the kinetics of nitrite reduction is the charge propagation in the film.

  18. The rational for a mid-scala electrode array.

    Science.gov (United States)

    Boyle, P J

    2016-06-01

    Today increasing numbers of cochlear implant candidates have residual hearing that can be aided and hence is worth trying to preserve. This means that surgical technique and electrode array design must be adapted to minimize trauma. Wide opening of the round window is often preferred to reduce drill related trauma and to avoid pressure spikes during electrode array insertion. A recent meta-analysis suggested that there is no significant correlation between hearing preservation and either insertion depth or scala position. However, a slow insertion speed of at least 30seconds was associated with better hearing preservation. An electrode design is proposed that targets the middle of the scala tympani. This minimizes frictional forces from either lateral or medial wall during insertion and imposes less static pressure on cochlear structures following insertion. The flexibility to insert via the round window requires a 0.7-mm maximum dimension at the proximal end of the array. Micro-anatomical analysis by micro-CT indicated that a 420-degree insertion depth was optimal between cochlear coverage and available space within the scala tympani. Physical measurements showed that mean insertion forces remained below 10mN during insertion. A series of 20 human temporal bone insertions found a mean insertion depth of 400 degrees with no scala dislocations. Six clinical series, in total 94 cases, found postoperative hearing in 81% of cases with a mean loss of 12dB compared to preoperative levels. Speech understanding out to one year post-fitting trended better for a mid-scala design group than for a straight electrode array group; although the differences were not statistically significant. A mid-scala array design appears able to be inserted with minimal trauma, to return a predictable insertion depth across various sizes of cochleae and to support reasonable levels of speech understanding without relying on residual hearing. Copyright © 2016. Published by Elsevier Masson

  19. Dye-sensitized solar cells using graphene-based carbon nano composite as counter electrode

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyonkwang; Kim, Hyunkook; Hwang, Sookhyun; Jeon, Minhyon [Department of Nano Systems Engineering, Center of Nano Manufacturing, Inje University, Obang, Gimhae, Gyungnam 621-749 (Korea, Republic of); Choi, Wonbong [Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States)

    2011-01-15

    We demonstrated a counter electrode in dye-sensitized solar cells (DSSCs) using the graphene-based multi-walled carbon nanotubes (GMWNTs) structure. Graphene layers were prepared by drop casting on a SiO{sub 2}/Si substrate and multi-walled carbon nanotubes (MWNTs) were synthesized on graphene layers using iron catalyst by chemical vapor deposition. The structural properties of GMWNTs were investigated by transmission electron microscope and field-emission scanning electron microscopy. The GMWNTs sheets were lifted off from the Si substrate by buffered oxide etching and were transplanted on fluorine-doped tin oxide glass by Van der Waals force as a counter electrode. From the electrochemical impedance spectroscopy and energy conversion efficiencies, electrochemical properties of GMWNTs were comparable with those of MWNTs counter electrode. The results suggested that GMWNTs were one of the candidates for a counter electrode for dye-sensitized solar cells. (author)

  20. Detection of cancer cells using a peptide nanotube–folic acid modified graphene electrode

    DEFF Research Database (Denmark)

    Castillo, John J.; Svendsen, Winnie Edith; Rozlosnik, Noemi

    2013-01-01

    This article describes the preparation of a graphene electrode modified with a new conjugate of peptide nanotubes and folic acid for the selective detection of human cervical cancer cells over-expressing folate receptors. The functionalization of peptide nanotubes with folic acid was confirmed...... by fluorescence microscopy and atomic force microscopy. The peptide nanotube–folic acid modified graphene electrode was characterized by scanning electron microscopy and cyclic voltammetry. The modification of the graphene electrode with peptide nanotube–folic acid led to an increase in the current signal....... The human cervical cancer cells were bound to the modified electrode through the folic acid–folate receptor interaction. Cyclic voltammograms in the presence of [Fe(CN)6]3/4 as a redox species demonstrated that the binding of the folate receptor from human cervical cancer cells to the peptide nanotube...

  1. Screen printed silver top electrode for efficient inverted organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junwoo [Department of Printed Electronics, Korea Institute of Machinery & Materials (KIMM), Daejeon (Korea, Republic of); Duraisamy, Navaneethan [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Lee, Taik-Min [Department of Printed Electronics, Korea Institute of Machinery & Materials (KIMM), Daejeon (Korea, Republic of); Kim, Inyoung, E-mail: ikim@kimm.re.kr [Department of Printed Electronics, Korea Institute of Machinery & Materials (KIMM), Daejeon (Korea, Republic of); Choi, Kyung-Hyun, E-mail: amm@jejunu.ac.kr [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of)

    2015-10-15

    Highlights: • Screen printing of silver pattern. • X-ray diffraction pattern confirmed the face centered cubic structure of silver. • Uniform surface morphology of silver pattern with sheet resistance of 0.06 Ω/sq. • The power conversion efficiency of fabricated solar cell is found to be 2.58%. - Abstract: The present work is mainly focused on replacement of the vacuum process for top electrode fabrication in organic solar cells. Silver top electrode deposited through solution based screen printing on pre-deposited polymeric thin film. The solution based printing technology provides uniform top electrode without damaging the underlying organic layers. The surface crystallinity and surface morphology of silver top electrode are examined through X-ray diffraction, field-emission scanning electron microscope and atomic force microscope. The purity of silver is examined through X-ray energy dispersive spectroscopy. The top electrode exhibits face centered cubic structure with homogeneous morphology. The sheet resistance of top electrode is found to be 0.06 Ω/sq and an average pattern thickness of ∼15 μm. The power conversion efficiency is 2.58%. Our work demonstrates that the solution based screen printing is a significant role in the replacement of vacuum process for the fabrication of top electrode in organic solar cells.

  2. Screen printed silver top electrode for efficient inverted organic solar cells

    International Nuclear Information System (INIS)

    Kim, Junwoo; Duraisamy, Navaneethan; Lee, Taik-Min; Kim, Inyoung; Choi, Kyung-Hyun

    2015-01-01

    Highlights: • Screen printing of silver pattern. • X-ray diffraction pattern confirmed the face centered cubic structure of silver. • Uniform surface morphology of silver pattern with sheet resistance of 0.06 Ω/sq. • The power conversion efficiency of fabricated solar cell is found to be 2.58%. - Abstract: The present work is mainly focused on replacement of the vacuum process for top electrode fabrication in organic solar cells. Silver top electrode deposited through solution based screen printing on pre-deposited polymeric thin film. The solution based printing technology provides uniform top electrode without damaging the underlying organic layers. The surface crystallinity and surface morphology of silver top electrode are examined through X-ray diffraction, field-emission scanning electron microscope and atomic force microscope. The purity of silver is examined through X-ray energy dispersive spectroscopy. The top electrode exhibits face centered cubic structure with homogeneous morphology. The sheet resistance of top electrode is found to be 0.06 Ω/sq and an average pattern thickness of ∼15 μm. The power conversion efficiency is 2.58%. Our work demonstrates that the solution based screen printing is a significant role in the replacement of vacuum process for the fabrication of top electrode in organic solar cells

  3. Simultaneous detection of ascorbic acid, uric acid and homovanillic acid at copper modified electrode

    International Nuclear Information System (INIS)

    Selvaraju, T.; Ramaraj, R.

    2007-01-01

    The copper was deposited on glassy carbon (GC) and indium tin oxide (ITO) electrodes by electrochemical method. The copper structures on electrode were characterized by atomic force microscope, X-ray diffractometeric pattern and differential pulse voltammetric studies. Optimal conditions for uniform growth of copper structures on the electrode were established. Voltammetric sensor was fabricated using the copper deposited GC electrode for the simultaneous detection and determination of uric acid (UA) and homovanillic acid (HVA) in the presence of excess concentrations of ascorbic acid (AA). The voltammetric signals due to AA and UA oxidation were well separated with a potential difference of 400 mV and AA did not interfere with the measurement of UA and HVA at the GC/Cu electrode. Linear calibration curves were obtained in the concentration range 1-40 μM for AA and 20-50 μM for UA at physiological pH and a detection limit of 10 nM of UA in the presence of 10-fold excess concentrations of AA was achieved. The simultaneous detection of submicromolar concentrations of AA, UA and HVA was achieved at the GC/Cu electrode. The practical utility of the present GC/Cu modified electrode was demonstrated by measuring the AA content in Vitamin C tablet, UA content in human urine and blood serum samples with satisfactory results

  4. Characterization of azo dyes on Pt and Pt/polyaniline/dispersed Pt electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Molina, J.; Fernandez, J.; Rio, A.I. del; Bonastre, J. [Departamento de Ingenieria Textil y Papelera, EPS de Alcoy, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell s/n, 03801 Alcoy (Spain); Cases, F., E-mail: fjcases@txp.upv.es [Departamento de Ingenieria Textil y Papelera, EPS de Alcoy, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell s/n, 03801 Alcoy (Spain)

    2012-06-15

    The electrochemical characterization of two organic dyes (amaranth and procion orange MX-2R) has been performed on Pt electrodes and Pt electrodes coated with polyaniline and dispersed Pt. Electrodes with different Pt loads have been synthesized and characterized obtaining that a load of 300 {mu}g cm{sup -2} was the optimum one. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) was employed to observe the distribution and morphology of the Pt nanoparticles. The electroactivity of the electrodes has also been characterized by means of scanning electrochemical microscopy (SECM). The chemical characterization of Pt dispersed Pani coated Pt electrodes (Pt-Pani-Pt) was performed by means of X-ray photoelectron spectroscopy (XPS). The electrochemical characterization of the dyes has been performed by means of cyclic voltammetry. Voltammograms have shown that the presence of the dyes diminishes characteristic Pt oxidation and reduction peaks. However, redox processes due to the dyes, appeared in the voltammograms. The different species responsible of these redox processes were generated in the vicinity of the electrode and were not adsorbed on the electrode surface since after stirring, the different redox processes disappeared. Characterization with different scan rates showed that redox processes of both dyes were controlled by diffusion.

  5. Bioelectrocatalytic mediatorless dioxygen reduction at carbon ceramic electrodes modified with bilirubin oxidase

    International Nuclear Information System (INIS)

    Nogala, Wojciech; Celebanska, Anna; Szot, Katarzyna; Wittstock, Gunther; Opallo, Marcin

    2010-01-01

    Carbon ceramic electrodes were prepared by sol-gel processing of a hydrophobic precursor - methyltrimethoxysilane (MTMOS) - together with dispersed graphite microparticles according to a literature procedure. Bilirubin oxidase (BOx) was adsorbed on this electrode from buffer solution and this process was followed by atomic force microscopy (AFM). The electrodes exhibited efficient mediatorless electrocatalytic activity towards dioxygen reduction. The activity depends on the time of adsorption of the enzyme and the pH. The electrode remains active in neutral solution. The bioelectrocatalytic activity is further increased when a fraction of the carbon microparticles is replaced by sulfonated carbon nanoparticles (CNPs). This additive enhances the electrical communication between the enzyme and the electronic conductor. At pH 7 the carbon ceramic electrode modified with bilirubin oxidase retains ca. half of its highest activity. The role of the modified nanoparticles is confirmed by experiments in which a film embedded in a hydrophobic silicate matrix also exhibited efficient mediatorless biocatalytic dioxygen reduction. Scanning electrochemical microscopy (SECM) of the studied electrodes indicated a rather even distribution of the catalytic activity over the electrode surface.

  6. Long life lithium batteries with stabilized electrodes

    Science.gov (United States)

    Amine, Khalil [Downers Grove, IL; Liu, Jun [Naperville, IL; Vissers, Donald R [Naperville, IL; Lu, Wenquan [Darien, IL

    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.

  7. Transition of poloidal viscosity by electrode biasing in the Large Helical Device

    International Nuclear Information System (INIS)

    Kitajima, S.; Ishii, K.; Takahashi, H.

    2012-11-01

    Electrode biasing experiments were tried in various magnetic configurations on the Large Helical Device (LHD). The transitions of poloidal viscosity, which were accompanied with bifurcation phenomena characterized by a negative resistance, were clearly observed on LHD by the electrode biasing. The critical external driving force required for transition were compared with the local maximum in ion viscosity, and the radial resistivity before the transition also compared with the expected value from a neoclassical theory. The critical driving force increased and the radial resistivity decreased with the major radius of the magnetic axis R ax going outward. The configuration dependence of the transition condition and the radial resistivity qualitatively agreed with neoclassical theories. The radial electric field and the viscosity were also evaluated by the neoclassical transport code for a non-axisymmetric system, and estimated electrode voltage required for the transition, which was consistent with the experimental results. (author)

  8. Characterization of Platinum Electrodes and In-situ Cell Confluency Measurement Based on Current Changes of Cell-Electrodes

    Directory of Open Access Journals (Sweden)

    Chin Fhong SOON

    2015-04-01

    Full Text Available This study aimed at the development of a biosensor to examine the growth confluency of human derived keratinocytes (HaCaT cell lines in-situ. The biosensor consists of a sputter- coated glass substrate with platinum patterns. Cells were grown on the conductive substrates and the confluency of the cells were monitored in-situ based on the conductivity changes of the substrates. Characterization of the cell proliferation and confluency were interrogated using electrical cell-substrate impedance sensing (ECIS techniques and current change of cells using a pico-ammeter. The investigation was followed by the electrical characterization of the platinum electrode (PE using a two probe I-V measurement system. The surface morphology of platinum electrodes were studied using an atomic force microscopy (AFM and the HaCaT cell morphology was studied using Field-Emission Scanning Electron Microscopy (FE-SEM. The microscopy results showed that the cells coupled and proliferated on the platinum electrodes. For monitoring the conductivity and impedance changes of the cell-electrode in-situ, the cover of a Petri dish was inserted with pogo pins to be in contact with the platinum electrodes. The impedance was sampled using the ECIS technique at a twenty-four hour interval. In our findings, the cell proliferation rate can be measured by observing the changes in capacitance or impedance measured at low ac frequencies ranged from 10 - 1 kHz. In good agreement, the current measured at micro-ampere range by the biosensor decreased as the cell coverage area increased over the time. Thus, the percent of cell confluence was shown inversely proportional to the current changes.

  9. Piercing by composite electrode tool

    International Nuclear Information System (INIS)

    Abdukarimov, Eh.T.; Krakov, B.G.; Saidinov, S.Ya.

    1990-01-01

    The construction of the electrode consisting of a dielectric shell, where a working liquid enters, and a metal rod is designed for precision super-deep piercing by the electroerosion treatment method. Technological parameters of piercing with small diameter (0.5-1.9 mm) for 12Kh18N10T steel, copper and tungsten are presented. A possibility to use a new tool for treating components of any form and sizes is marked

  10. Redox electrode materials for supercapatteries

    OpenAIRE

    Yu, Linpo; Chen, George Z.

    2016-01-01

    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...

  11. Analytic Potentials for Realistic Electrodes

    International Nuclear Information System (INIS)

    Barlow, Stephan E.; Taylor, Aimee E.; Swanson, Kenneth R.

    2002-01-01

    Finite difference algorithms are widely used to numerically solve Laplace's equation for electrode structures that are not amendable to analytic treatment. This includes essentially all real situations. However, in many cases, it is desirable to have the solution in an analytic form. A common practice is to 'fit' the numerical solution either by least squares or cubic spline approach. Neither of these approaches is really accurate, nor do they produce unique results. These limitations are avoided by our approach.

  12. Potentiometric titration with polarized electrodes

    International Nuclear Information System (INIS)

    Chikryzova, E.G.

    1977-01-01

    Based on the analysis of the works carried out during 1911-75 consideration is given to the present state of the method of potentiometric titration with polarized electrodes. The material is generalized in the tabular form indicating the elments of interest, titration conditions and the objects to be analyzed. The list and classification of the potentiometric titration methods intended for determining organic and inorganic substances are presented

  13. Surface modification of recording electrodes

    Directory of Open Access Journals (Sweden)

    Iaci Miranda Pereira

    2013-01-01

    Full Text Available 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 cardiac fibroblasts and rat cardiomyocytes when in contact with an electrode surface. Diisocyanate and poly(caprolactone diol were the main reagents for producing PUs. The electrochemical impedance of the electrode/electrolyte interface was accessed by electrochemical impedance spectroscopy. The cellular viability, proliferation, and morphology changes were investigated using an MTT assay. Cardiomyocyte adherence was observed by scanning electron microscopy. The obtained surface was uniform, flat, and transparent. The film showed good adhesion, and no peeling was detected. The electrochemical impedance decreased over time and was influenced by the ionic permeability of the PU layer. The five samples did not show cytotoxicity when in contact with neonatal rat cells.

  14. Modeling of Changing Electrode Profiles

    Energy Technology Data Exchange (ETDEWEB)

    Prentice, Geoffrey Allen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials and Molecular Research Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering

    1980-12-01

    A model for simulating the transient behavior of solid electrodes undergoing deposition or dissolution has been developed. The model accounts for ohmic drop, charge transfer overpotential, and mass transport limitations. The finite difference method, coupled with successive overrelaxation, was used as the basis of the solution technique. An algorithm was devised to overcome the computational instabilities associated with the calculations of the secondary and tertiary current distributions. Simulations were performed on several model electrode profiles: the sinusoid, the rounded corner, and the notch. Quantitative copper deposition data were obtained in a contoured rotating cylinder system, Sinusoidal cross-sections, machined on stainless steel cylinders, were used as model geometries, Kinetic parameters for use in the simulation were determined from polarization curves obtained on copper rotating cylinders, These parameters, along with other physical property and geometric data, were incorporated in simulations of growing sinusoidal profiles. The copper distributions on the sinusoidal cross-sections were measured and found to compare favorably with the simulated results. At low Wagner numbers the formation of a slight depression at the profile peak was predicted by the simulation and observed on the profile. At higher Wagner numbers, the simulated and experimental results showed that the formation of a depression was suppressed. This phenomenon was shown to result from the competition between ohmic drop and electrode curvature.

  15. Lithium manganese oxide spinel electrodes

    Science.gov (United States)

    Darling, Robert Mason

    Batteries based oil intercalation eletrodes are currently being considered for a variety of applications including automobiles. This thesis is concerned with the simulation and experimental investigation of one such system: spinel LiyMn2O4. A mathematical model simulating the behavior of an electrochemical cell containing all intercalation electrode is developed and applied to Li yMn2O4 based systems. The influence of the exchange current density oil the propagation of the reaction through the depth of the electrode is examined theoretically. Galvanostatic cycling and relaxation phenomena on open circuit are simulated for different particle-size distributions. The electrode with uniformly sized particles shows the best performance when the current is on, and relaxes towards equilibrium most quickly. The impedance of a porous electrode containing a particle-size distribution at low frequencies is investigated with all analytic solution and a simplified version of the mathematical model. The presence of the particle-size distribution leads to an apparent diffusion coefficient which has all incorrect concentration dependence. A Li/1 M LiClO4 in propylene carbonate (PC)/ LiyMn 2O4 cell is used to investigate the influence of side reactions oil the current-potential behavior of intercalation electrodes. Slow cyclic voltammograms and self-discharge data are combined to estimate the reversible potential of the host material and the kinetic parameters for the side reaction. This information is then used, together with estimates of the solid-state diffusion coefficient and main-reaction exchange current density, in a mathematical model of the system. Predictions from the model compare favorably with continuous cycling results and galvanostatic experiments with periodic current interruptions. The variation with respect to composition of' the diffusion coefficient of lithium in LiyMn2O4 is estimated from incomplete galvanostatic discharges following open-circult periods. The

  16. Electrode phenomena, tensor conductivity and electrode heating in seeded argon

    Energy Technology Data Exchange (ETDEWEB)

    Croitoru, Z.; de Montardy, A.

    1963-04-15

    Contact potential drops along the electrodes often prevent measurements of ionized gas conductivity. In order to avoid such potential drops, a measurement cell using double probe technique was realized. By adding a third probe, it is also possible to measure the conductivity tensor components. Formulas commonly used are shown to be incorrect. In order to evaluate non- equilibrium conductivity, the excitation temperature of the seed is to be considered, rather than electron temperature, especially in small scale experiments, where charged particle losses by ambipolar diffusion are to be expected. (auth)

  17. Bifunctional electrodes for unitised regenerative fuel cells

    International Nuclear Information System (INIS)

    Altmann, Sebastian; Kaz, Till; Friedrich, Kaspar Andreas

    2011-01-01

    Research highlights: → Different oxygen electrode configurations for the operation in a unitised reversible fuel cell were tested. → Polarisation curves and EIS measurements were recorded. → The mixture of catalysts performs best for the present stage of electrode development. → Potential improvements for the different compositions are discussed. - Abstract: The effects of different configurations and compositions of platinum and iridium oxide electrodes for the oxygen reaction of unitised regenerative fuel cells (URFC) are reported. Bifunctional oxygen electrodes are important for URFC development because favourable properties for the fuel cell and the electrolysis modes must be combined into a single electrode. The bifunctional electrodes were studied under different combinations of catalyst mixtures, multilayer arrangements and segmented configurations with single catalyst areas. Distinct electrochemical behaviour was observed for both modes and can be explained on the basis of impedance spectroscopy. The mixture of both catalysts performs best for the present stage of electrode development. Also, the multilayer electrodes yielded good results with the potential for optimisation. The influence of ionic and electronic resistances on the relative performance is demonstrated. However, penalties due to cross currents in the heterogeneous electrodes were identified and explained by comparing the performance curves with electrodes composed of a single catalyst. Potential improvements for the different compositions are discussed.

  18. 3D Printed Dry EEG Electrodes.

    Science.gov (United States)

    Krachunov, Sammy; Casson, Alexander J

    2016-10-02

    Electroencephalography (EEG) is a procedure that records brain activity in a non-invasive manner. The cost and size of EEG devices has decreased in recent years, facilitating a growing interest in wearable EEG that can be used out-of-the-lab for a wide range of applications, from epilepsy diagnosis, to stroke rehabilitation, to Brain-Computer Interfaces (BCI). A major obstacle for these emerging applications is the wet electrodes, which are used as part of the EEG setup. These electrodes are attached to the human scalp using a conductive gel, which can be uncomfortable to the subject, causes skin irritation, and some gels have poor long-term stability. A solution to this problem is to use dry electrodes, which do not require conductive gel, but tend to have a higher noise floor. This paper presents a novel methodology for the design and manufacture of such dry electrodes. We manufacture the electrodes using low cost desktop 3D printers and off-the-shelf components for the first time. This allows quick and inexpensive electrode manufacturing and opens the possibility of creating electrodes that are customized for each individual user. Our 3D printed electrodes are compared against standard wet electrodes, and the performance of the proposed electrodes is suitable for BCI applications, despite the presence of additional noise.

  19. 3D Printed Dry EEG Electrodes

    Directory of Open Access Journals (Sweden)

    Sammy Krachunov

    2016-10-01

    Full Text Available Electroencephalography (EEG is a procedure that records brain activity in a non-invasive manner. The cost and size of EEG devices has decreased in recent years, facilitating a growing interest in wearable EEG that can be used out-of-the-lab for a wide range of applications, from epilepsy diagnosis, to stroke rehabilitation, to Brain-Computer Interfaces (BCI. A major obstacle for these emerging applications is the wet electrodes, which are used as part of the EEG setup. These electrodes are attached to the human scalp using a conductive gel, which can be uncomfortable to the subject, causes skin irritation, and some gels have poor long-term stability. A solution to this problem is to use dry electrodes, which do not require conductive gel, but tend to have a higher noise floor. This paper presents a novel methodology for the design and manufacture of such dry electrodes. We manufacture the electrodes using low cost desktop 3D printers and off-the-shelf components for the first time. This allows quick and inexpensive electrode manufacturing and opens the possibility of creating electrodes that are customized for each individual user. Our 3D printed electrodes are compared against standard wet electrodes, and the performance of the proposed electrodes is suitable for BCI applications, despite the presence of additional noise.

  20. HVDC Ground Electrodes and Tectonic Setting

    Science.gov (United States)

    Freire, P. F.; Pereira, S. Y.

    2017-12-01

    Ground electrodes in HVDC transmission are huge grounding systems for the DC part of the converter substation, about 1 km wide, sized to inject in the ground DC currents up to 3.5 kA. This work presents an analysis of how the tectonic setting at converter substation location is determinant for the search of the best electrode location (Site Selection) and on its design and performance. It will briefly present the author experience on HVDC electrode design, summarized as follows: Itaipu - Foz do Iguaçu electrodes (transmitter side) located in the middle of Paraná Sedimentary Basin, and Ibiúna electrodes (receiving side) on the border of the basin, 6 km from the geological strike, where the crystalline basement outcrops in São Paulo state; Madeira River - North electrodes (transmitting side) located on the Northwest border of South Amazon Craton, where the crystalline basement is below a shallow sediments layer, and South electrodes (receiving side) located within Paraná Sedimentary Basin; Chile - electrodes located on the Andean forearc, where the Nazca Plate plunges under the South American Plate; Kenya - Ethiopia - electrodes located in the African Rift; Belo Monte - North electrodes (transmitter side) located within the Amazonian Sedimentary Basin, about 35 km of its South border, and South electrodes (receiving side) within Paraná Sedimentary Basin (bipole 1) and on crystalline metamorphic terrain "Brasília Belt" (bipole 2). This diversity of geological conditions results on ground electrodes of different topologies and dimensions, with quite different electrical and thermal performances. A brief study of the geology of the converter stations regions, the so-called Desktop Study, allows for the preview of several important parameters for the site selection and design of the electrodes, such as localization, type, size and estimate of the interference area, which are important predictors of the investment to be made and indications of the design to be

  1. 12th Air Force > Home

    Science.gov (United States)

    Force AOR Travel Info News prevnext Slide show 76,410 pounds of food delivered to Haiti 12th Air Force the French Air Force, Colombian Air Force, Pakistan Air Force, Belgian Air Force, Brazilian Air Force

  2. Feasibility of novel four degrees of freedom capacitive force sensor for skin interface force

    Directory of Open Access Journals (Sweden)

    Murakami Chisato

    2012-11-01

    Full Text Available Abstract Background The objective of our study was to develop a novel capacitive force sensor that enables simultaneous measurements of yaw torque around the pressure axis and normal force and shear forces at a single point for the purpose of elucidating pressure ulcer pathogenesis and establishing criteria for selection of cushions and mattresses. Methods Two newly developed sensors (approximately 10 mm×10 mm×5 mm (10 and 20 mm×20 mm×5 mm (20 were constructed from silicone gel and four upper and lower electrodes. The upper and lower electrodes had sixteen combinations that had the function as capacitors of parallel plate type. The full scale (FS ranges of force/torque were defined as 0–1.5 N, –0.5-0.5 N and −1.5-1.5 N mm (10 and 0–8.7 N, –2.9-2.9 N and −16.8-16.8 N mm (20 in normal force, shear forces and yaw torque, respectively. The capacitances of sixteen capacitors were measured by an LCR meter (AC1V, 100 kHz when displacements corresponding to four degrees of freedom (DOF forces within FS ranges were applied to the sensor. The measurement was repeated three times in each displacement condition (10 only. Force/torque were calculated by corrected capacitance and were evaluated by comparison to theoretical values and standard normal force measured by an universal tester. Results In measurements of capacitance, the coefficient of variation was 3.23% (10. The Maximum FS errors of estimated force/torque were less than or equal to 10.1 (10 and 16.4% (20, respectively. The standard normal forces were approximately 1.5 (10 and 9.4 N (20 when pressure displacements were 3 (10 and 2 mm (20, respectively. The estimated normal forces were approximately 1.5 (10 and 8.6 N (10 in the same condition. Conclusions In this study, we developed a new four DOF force sensor for measurement of force/torque that occur between the skin and a mattress. In measurement of capacitance, the repeatability was good and it was confirmed that the sensor had

  3. Spectroscopic and electrochemical characterization of nanostructured optically transparent carbon electrodes.

    Science.gov (United States)

    Benavidez, Tomás E; Garcia, Carlos D

    2013-07-01

    The present paper describes the results related to the optical and electrochemical characterization of thin carbon films fabricated by spin coating and pyrolysis of AZ P4330-RS photoresist. The goal of this paper is to provide comprehensive information allowing for the rational selection of the conditions to fabricate optically transparent carbon electrodes (OTCE) with specific electrooptical properties. According to our results, these electrodes could be appropriate choices as electrochemical transducers to monitor electrophoretic separations. At the core of this manuscript is the development and critical evaluation of a new optical model to calculate the thickness of the OTCE by variable angle spectroscopic ellipsometry. Such data were complemented with topography and roughness (obtained by atomic force microscopy), electrochemical properties (obtained by cyclic voltammetry), electrical properties (obtained by electrochemical impedance spectroscopy), and structural composition (obtained by Raman spectroscopy). Although the described OTCE were used as substrates to investigate the effect of electrode potential on the real-time adsorption of proteins by ellipsometry, these results could enable the development of other biosensors that can be then integrated into various CE platforms. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Single-wall carbon nanotube chemical attachment at platinum electrodes

    International Nuclear Information System (INIS)

    Rosario-Castro, Belinda I.; Contes-de-Jesus, Enid J.; Lebron-Colon, Marisabel; Meador, Michael A.; Scibioh, M. Aulice; Cabrera, Carlos R.

    2010-01-01

    Self-assembled monolayer (SAM) techniques were used to adsorb 4-aminothiophenol (4-ATP) on platinum electrodes in order to obtain an amino-terminated SAM as the base for the chemical attachment of single-wall carbon nanotubes (SWCNTs). A physico-chemical, morphological and electrochemical characterizations of SWCNTs attached onto the modified Pt electrodes was done by using reflection-absorption infrared spectroscopy (RAIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and cyclic voltammetry (CV) techniques. The SWNTs/4-ATP/Pt surface had regions of small, medium, and large thickness of carbon nanotubes with heights of 100-200 nm, 700 nm to 1.5 μm, and 1.0-3.0 μm, respectively. Cyclic voltammetries (CVs) in sulfuric acid demonstrated that attachment of SWNTs on 4-ATP/Pt is markedly stable, even after 30 potential cycles. CV in ruthenium hexamine was similar to bare Pt electrodes, suggesting that SWNTs assembly is similar to a closely packed microelectrode array.

  5. Technology of high-speed combined machining with brush electrode

    Science.gov (United States)

    Kirillov, O. N.; Smolentsev, V. P.; Yukhnevich, S. S.

    2018-03-01

    The new method was proposed for high-precision dimensional machining with a brush electrode when the true position of bundles of metal wire is adjusted by means of creating controlled centrifugal forces appeared due to the increased frequency of rotation of a tool. There are the ultimate values of circumferential velocity at which the bundles are pressed against a machined area of a workpiece in a stable manner despite the profile of the machined surface and variable stock of the workpiece. The special aspects of design of processing procedures for finishing standard parts, including components of products with low rigidity, are disclosed. The methodology of calculation and selection of processing modes which allow one to produce high-precision details and to provide corresponding surface roughness required to perform finishing operations (including the preparation of a surface for metal deposition) is presented. The production experience concerned with the use of high-speed combined machining with an unshaped tool electrode in knowledge-intensive branches of the machine-building industry for different types of production is analyzed. It is shown that the implementation of high-speed dimensional machining with an unshaped brush electrode allows one to expand the field of use of the considered process due to the application of a multipurpose tool in the form of a metal brush, as well as to obtain stable results of finishing and to provide the opportunities for long-term operation of the equipment without its changeover and readjustment.

  6. Atomic force microscope characterization of a resonating nanocantilever

    DEFF Research Database (Denmark)

    Abadal, G.; Davis, Zachary James; Borrise, X.

    2003-01-01

    An atomic force microscope (AFM) is used as a nanometer-scale resolution tool for the characterization of the electromechanical behaviour of a resonant cantilever-based mass sensor. The cantilever is actuated electrostatically by applying DC and AC voltages from a driver electrode placed closely...

  7. 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.

  8. 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.

  9. Aluminum-carbon composite electrode

    Science.gov (United States)

    Farahmandi, C. Joseph; Dispennette, John M.

    1998-07-07

    A high performance double layer capacitor having an electric double layer formed in the interface between activated carbon and an electrolyte is disclosed. The high performance double layer capacitor includes a pair of aluminum impregnated carbon composite electrodes having an evenly distributed and continuous path of aluminum impregnated within an activated carbon fiber preform saturated with a high performance electrolytic solution. The high performance double layer capacitor is capable of delivering at least 5 Wh/kg of useful energy at power ratings of at least 600 W/kg.

  10. Electrochemical cell and negative electrode therefor

    Science.gov (United States)

    Kaun, Thomas D.

    1982-01-01

    A secondary electrochemical cell with the positive and negative electrodes separated by a molten salt electrolyte with the negative electrode comprising a particulate mixture of lithium-aluminum alloy and electrolyte and an additive selected from graphitized carbon, Raney iron or mixtures thereof. The lithium-aluminum alloy is present in the range of from about 45 to about 80 percent by volume of the negative electrode, and the electrolyte is present in an amount not less than about 10 percent by volume of the negative electrode. The additive of graphitized carbon is present in the range of from about 1 to about 10 percent by volume of the negative electrode, and the Raney iron additive is present in the range of from about 3 to about 10 percent by volume of the negative electrode.

  11. 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.

  12. Silver manganese oxide electrodes for lithium batteries

    Science.gov (United States)

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

    2006-05-09

    This invention relates to electrodes for non-aqueous lithium cells and batteries with silver manganese oxide positive electrodes, denoted AgxMnOy, in which x and y are such that the manganese ions in the charged or partially charged electrodes cells have an average oxidation state greater than 3.5. The silver manganese oxide electrodes optionally contain silver powder and/or silver foil to assist in current collection at the electrodes and to improve the power capability of the cells or batteries. The invention relates also to a method for preparing AgxMnOy electrodes by decomposition of a permanganate salt, such as AgMnO4, or by the decomposition of KMnO4 or LiMnO4 in the presence of a silver salt.

  13. Graphene electrodes for stimulation of neuronal cells

    International Nuclear Information System (INIS)

    Koerbitzer, Berit; Nick, Christoph; Thielemann, Christiane; Krauss, Peter; Yadav, Sandeep; Schneider, Joerg J

    2016-01-01

    Graphene has the ability to improve the electrical interface between neuronal cells and electrodes used for recording and stimulation purposes. It provides a biocompatible coating for common electrode materials such as gold and improves the electrode properties. Graphene electrodes are also prepared on SiO 2 substrate to benefit from its optical properties like transparency. We perform electrochemical and Raman characterization of gold electrodes with graphene coating and compare them with graphene on SiO 2 substrate. It was found that the substrate plays an important role in the performance of graphene and show that graphene on SiO 2 substrate is a very promising material combination for stimulation electrodes. (paper)

  14. Investigation of Imbalanced Activated Carbon Electrode Supercapacitors

    OpenAIRE

    Tieshi He; Xue Ren; Junping Nie; Jun Ying; Kedi Cai

    2015-01-01

    Imbalanced supercapacitor was constructed by using various ratio of activated carbon (AC) of positive to negative electrode. The electrochemical behavior of imbalanced supercapacitor was investigated using 1.0 M spiro-(1,1′)-bipyrrolidinium tetrafluoroborate electrolyte in propylene carbonate. The results showed that there are some factors that influenced the imbalanced supercapacitor with different AC ratio of positive to negative electrode, the utilization of AC, electrode potential distrib...

  15. 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)

  16. Combined use of transcranial magnetic stimulation and metal electrode implants: a theoretical assessment of safety considerations

    Science.gov (United States)

    Golestanirad, Laleh; Rouhani, Hossein; Elahi, Behzad; Shahim, Kamal; Chen, Robert; Mosig, Juan R.; Pollo, Claudio; Graham, Simon J.

    2012-12-01

    This paper provides a theoretical assessment of the safety considerations encountered in the simultaneous use of transcranial magnetic stimulation (TMS) and neurological interventions involving implanted metallic electrodes, such as electrocorticography. Metal implants are subject to magnetic forces due to fast alternating magnetic fields produced by the TMS coil. The question of whether the mechanical movement of the implants leads to irreversible damage of brain tissue is addressed by an electromagnetic simulation which quantifies the magnitude of imposed magnetic forces. The assessment is followed by a careful mechanical analysis determining the maximum tolerable force which does not cause irreversible tissue damage. Results of this investigation provide useful information on the range of TMS stimulator output powers which can be safely used in patients having metallic implants. It is shown that conventional TMS applications can be considered safe when applied on patients with typical electrode implants as the induced stress in the brain tissue remains well below the limit of tissue damage.

  17. Fabricating solid carbon porous electrodes from powders

    Science.gov (United States)

    Kaschmitter, James L.; Tran, Tri D.; Feikert, John H.; Mayer, Steven T.

    1997-01-01

    Fabrication of conductive solid porous carbon electrodes for use in batteries, double layer capacitors, fuel cells, capacitive dionization, and waste treatment. Electrodes fabricated from low surface area (Electrodes having a higher surface area, fabricated from powdered carbon blacks, such as carbon aerogel powder, carbon aerogel microspheres, activated carbons, etc. yield high conductivity carbon compositives with excellent double layer capacity, and can be used in double layer capacitors, or for capacitive deionization and/or waste treatment of liquid streams. By adding metallic catalysts to be high surface area carbons, fuel cell electrodes can be produced.

  18. 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.

  19. 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.

  20. Study of electrochemical behavior of desatinib using hanging mercury drop electrode and gold disc electrode

    Czech Academy of Sciences Publication Activity Database

    Nováková, Kateřina; Navrátil, Tomáš; Jaklová Dytrtová, Jana; Jakl, M.

    2015-01-01

    Roč. 11, č. 1 (2015), s. 116-116 ISSN 1336-7242 Institutional support: RVO:61388955 ; RVO:61388963 Keywords : electrochemistry * hanging mercury drop electrode * gold electrode Subject RIV: CG - Electrochemistry

  1. Electrodes as Terminal Electron Acceptors in Anaerobic Ammonium Oxidation

    Science.gov (United States)

    Ruiz-Urigüen, M.; Jaffe, P. R.

    2017-12-01

    Anaerobic ammonium (NH4+) oxidation under iron (Fe) reducing conditions is a microbial- mediated process known as Feammox. This is a novel pathway in the nitrogen cycle, and a key process for alleviating NH4+ accumulation in anoxic soils, wetlands, and wastewater. Acidimicrobiaceae-bacterium A6, phylum Actinobacteria, are one type of autotrophic bacteria linked to this process. The Feammox-bacteria obtain their energy by oxidizing NH4+ and transferring the electrons to a terminal electron acceptor (TEA). Under environmental conditions, iron oxides are the TEAs. However, in this study we show that electrodes in Microbial Electrolysis Cells (MECs) or electrodes set in the field can be used as TEAs by Feammox-bacteria. The potential difference between electrodes is the driving force for electron transfer, making the reaction energetically feasible. Our results show that MECs containing Feammox cultures can remove NH4+ up to 3.5 mg/L in less than 4 hours, compared to an average of 9 mg/L in 2 weeks when cultured under traditional conditions. Concomitantly, MECs produce an average current of 30.5 A/m3 whilst dead bacteria produced low (Actinobacteria when compared to bulk soil. Electrodes as TEAs enhance electrogenic bacteria recovery and culturing. The use of MECs for the productions of Feammox-bacteria eliminates the dependence of Fe, a finite electron acceptor, therefore, allowing for continuous NH4+ removal. Finally, Fe-free Feammox-bacteria can be applied to reduce other metals of environmental concern; therefore, opening the range of possible application of Feammox-bacteria.

  2. Asymmetric Supercapacitor Electrodes and Devices.

    Science.gov (United States)

    Choudhary, Nitin; Li, Chao; Moore, Julian; Nagaiah, Narasimha; Zhai, Lei; Jung, Yeonwoong; Thomas, Jayan

    2017-06-01

    The world is recently witnessing an explosive development of novel electronic and optoelectronic devices that demand more-reliable power sources that combine higher energy density and longer-term durability. Supercapacitors have become one of the most promising energy-storage systems, as they present multifold advantages of high power density, fast charging-discharging, and long cyclic stability. However, the intrinsically low energy density inherent to traditional supercapacitors severely limits their widespread applications, triggering researchers to explore new types of supercapacitors with improved performance. Asymmetric supercapacitors (ASCs) assembled using two dissimilar electrode materials offer a distinct advantage of wide operational voltage window, and thereby significantly enhance the energy density. Recent progress made in the field of ASCs is critically reviewed, with the main focus on an extensive survey of the materials developed for ASC electrodes, as well as covering the progress made in the fabrication of ASC devices over the last few decades. Current challenges and a future outlook of the field of ASCs are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. 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.

  4. Improving electromechanical output of IPMC by high surface area Pd-Pt electrodes and tailored ionomer membrane thickness

    Directory of Open Access Journals (Sweden)

    Viljar Palmre

    2014-04-01

    Full Text Available In this study, we attempt to improve the electromechanical performance of ionic polymer–metal composites (IPMCs by developing high surface area Pd-Pt electrodes and tailoring the ionomer membrane thickness. With proper electroless plating techniques, a high dispersion of palladium particles is achieved deep in the ionomer membrane, thereby increasing notably the interfacial surface area of electrodes. The membrane thickness is increased using 0.5 and 1 mm thick ionomer films. For comparison, IPMCs with the same ionomer membranes, but conventional Pt electrodes, are also prepared and studied. The electromechanical, mechanoelectrical, electrochemical and mechanical properties of different IPMCs are characterized and discussed. Scanning electron microscopy-energy dispersive X-ray (SEM-EDS is used to investigate the distribution of deposited electrode metals in the cross section of Pd-Pt IPMCs. Our experiments demonstrate that IPMCs assembled with millimeter thick ionomer membranes and newly developed Pd-Pt electrodes are superior in mechanoelectrical transduction, and show significantly higher blocking force compared to conventional type of IPMCs. The blocking forces of more than 0.3 N were measured at 4V DC input, exceeding the force output of typical Nafion® 117-based Pt IPMCs more than two orders of magnitude. The newly designed Pd-Pt IPMCs can be useful in more demanding applications, e.g., in biomimetic underwater robotics, where high stress and drag forces are encountered.

  5. Modulating indium doped tin oxide electrode properties for laccase electron transfer enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Diaconu, Mirela [National Institute for Biological Sciences, Centre of Bioanalysis, 296 Spl. Independentei, Bucharest 060031 (Romania); Chira, Ana [National Institute for Biological Sciences, Centre of Bioanalysis, 296 Spl. Independentei, Bucharest 060031 (Romania); Politehnica University of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu Str., 011061 (Romania); Radu, Lucian, E-mail: gl_radu@chim.upb.ro [Politehnica University of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu Str., 011061 (Romania)

    2014-08-28

    Indium doped tin oxide (ITO) electrodes were functionalized with gold nanoparticles (GNPs) and cysteamine monolayer to enhance the heterogeneous electron transfer process of laccase from Trametes versicolor. The assembly of GNP on ITO support was performed through generation of H{sup +} species at the electrode surface by hydroquinone electrooxidation at 0.9 V vs Ag/AgCl. Uniform distribution of gold nanoparticle aggregates on electrode surfaces was confirmed by atomic force microscopy. The size of GNP aggregates was in the range of 200–500 nm. The enhanced charge transfer at the GNP functionalized ITO electrodes was observed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy. Electrocatalytic behavior of laccase immobilized on ITO modified electrode toward oxygen reduction reaction was evaluated using CV in the presence of 2,2′-azino-bis 3-ethylbenzothiazoline-6-sulfuric acid (ABTS). The obtained sigmoidal-shaped voltammograms for ABTS reduction in oxygen saturated buffer solution are characteristic for a catalytic process. The intensity of catalytic current increased linearly with mediator concentration up to 6.2 × 10{sup −4} M. The registered voltammogram in the absence of ABTS mediator clearly showed a significant faradaic current which is the evidence of the interfacial oxygen reduction. - Highlights: • Assembly of gold nanoparticles on indium tin oxide support at positive potentials • Electrochemical and morphological evaluation of the gold nanoparticle layer assembly • Bioelectrocatalytic oxygen reduction on laccase modified electrode.

  6. Handbook of force transducers

    CERN Document Server

    Stefanescu, Dan Mihai

    2011-01-01

    Part I introduces the basic ""Principles and Methods of Force Measurement"" acording to a classification into a dozen of force transducers types: resistive, inductive, capacitive, piezoelectric, electromagnetic, electrodynamic, magnetoelastic, galvanomagnetic (Hall-effect), vibrating wires, (micro)resonators, acoustic and gyroscopic. Two special chapters refer to force balance techniques and to combined methods in force measurement. Part II discusses the ""(Strain Gauge) Force Transducers Components"", evolving from the classical force transducer to the digital / intelligent one, with the inco

  7. Polymer Coatings of Cochlear Implant Electrode Surface - An Option for Improving Electrode-Nerve-Interface by Blocking Fibroblast Overgrowth.

    Directory of Open Access Journals (Sweden)

    C Hadler

    Full Text Available Overgrowth of connective tissue and scar formation induced by the electrode array insertion increase the impedance and, thus, diminish the interactions between neural probes as like cochlear implants (CI and the target tissue. Therefore, it is of great clinical interest to modify the carrier material of the electrodes to improve the electrode nerve interface for selective cell adhesion. On one side connective tissue growth needs to be reduced to avoid electrode array encapsulation, on the other side the carrier material should not compromise the interaction with neuronal cells. The present in vitro-study qualitatively and quantitatively characterises the interaction of fibroblasts, glial cells and spiral ganglion neurons (SGN with ultrathin poly(N,N-dimethylacrylamide (PDMAA, poly(2-ethyloxazoline (PEtOx and poly([2-methacryloyloxyethyl]trimethylammoniumchlorid (PMTA films immobilised onto glass surfaces using a photoreactive anchor layer. The layer thickness and hydrophilicity of the polymer films were characterised by ellipsometric and water contact angle measurement. Moreover the topography of the surfaces was investigated using atomic force microscopy (AFM. The neuronal and non-neuronal cells were dissociated from spiral ganglions of postnatal rats and cultivated for 48 h on top of the polymer coatings. Immunocytochemical staining of neuronal and intermediary filaments revealed that glial cells predominantly attached on PMTA films, but not on PDMAA and PEtOx monolayers. Hereby, strong survival rates and neurite outgrowth were only found on PMTA, whereas PDMAA and PEtOx coatings significantly reduced the SG neuron survival and neuritogenesis. As also shown by scanning electron microscopy (SEM SGN strongly survived and retained their differentiated phenotype only on PMTA. In conclusion, survival and neuritogenesis of SGN may be associated with the extent of the glial cell growth. Since PMTA was the only of the polar polymers used in this study

  8. Analytical Formulation of the Electric Field Induced by Electrode Arrays: Towards Automated Dielectrophoretic Cell Sorting

    Directory of Open Access Journals (Sweden)

    Vladimir Gauthier

    2017-08-01

    Full Text Available Dielectrophoresis is defined as the motion of an electrically polarisable particle in a non-uniform electric field. Current dielectrophoretic devices enabling sorting of cells are mostly controlled in open-loop applying a predefined voltage on micro-electrodes. Closed-loop control of these devices would enable to get advanced functionalities and also more robust behavior. Currently, the numerical models of dielectrophoretic force are too complex to be used in real-time closed-loop control. The aim of this paper is to propose a new type of models usable in this framework. We propose an analytical model of the electric field based on Fourier series to compute the dielectrophoretic force produced by parallel electrode arrays. Indeed, this method provides an analytical expression of the electric potential which decouples the geometrical factors (parameter of our system, the voltages applied on electrodes (input of our system, and the position of the cells (output of our system. Considering the Newton laws on each cell, it enables to generate easily a dynamic model of the cell positions (output function of the voltages on electrodes (input. This dynamic model of our system is required to design the future closed-loop control law. The predicted dielectrophoretic forces are compared to a numerical simulation based on finite element model using COMSOL software. The model presented in this paper enables to compute the dielectrophoretic force applied to a cell by an electrode array in a few tenths of milliseconds. This model could be consequently used in future works for closed-loop control of dielectrophoretic devices.

  9. Electrochemical Oxidation of Glycerol Using Gold Electrode

    International Nuclear Information System (INIS)

    Mohamed Rozali Othman; Amirah Ahmad

    2015-01-01

    Cyclic voltammetry, potential linear V and chronocuolometry methods were carried out to gain electrochemical behavior of glycerol at a gold electrode. Potassium hydroxide and sulfuric acid were chosen to be the electrolyte for the electro-oxidation of this organic compound. Besides gold plate electrode, gold composite electrode (Au-PVC) was also used as the working electrode. The Au-PVC composite electrode was characterized by Scanning Electron Microscopy (SEM) to determine its morphological aspects before and after used in electrochemical oxidation of glycerol. In alkaline solution, the adsorption of hydroxide species onto the surface of both gold plate and composite Au-PVC electrodes occurs at potential around 500 mV vs SCE. However, at gold plate electrode, there was a small, broad peak before the drastic escalation of current densities which indicates the charge transfer of the chemisorbed OH - anion. In acidic media, the gold oxide was formed after potential 1.0 V. From the cyclic voltammogram glycerol undergo oxidation twice in potassium hydroxide at gold plate and Au-PVC composite electrodes, while in sulfuric acid, oxidation reaction happened once for glycerol on the gold plate electrode. Overall, electrochemical oxidation of glycerol was more effective in alkaline media. Tafel graph which plotted from potential linear V method shows that Au-PVC composite electrode is better than gold plate electrode for the electro-oxidation of glycerol in alkaline solution. Electrochemical oxidation of glycerol products as analyzed by Gas Chromatography-Mass Spectrometry (GC-MS) produced several carboxylic acids and phenolic compounds. (author)

  10. Realising traceable electrostatic forces despite non-linear balance motion

    International Nuclear Information System (INIS)

    Stirling, Julian; Shaw, Gordon A

    2017-01-01

    Direct realisation of force, traceable to fundamental constants via electromagnetic balances, is a key goal of the proposed redefinition of the international system of units (SI). This will allow small force metrology to be performed using an electrostatic force balance (EFB) rather than subdivision of larger forces. Such a balance uses the electrostatic force across a capacitor to balance an external force. In this paper we model the capacitance of a concentric cylinder EFB design as a function of the displacement of its free electrode, accounting for the arcuate motion produced by parallelogram linkages commonly used in EFB mechanisms. From this model we suggest new fitting procedures to reduce uncertainties arising from non-linear motion as well as methods to identify misalignment of the mechanism. Experimental studies on both a test capacitor and the NIST EFB validate the model. (paper)

  11. Origin of current-induced forces in an atomic gold wire: A first-principles study

    DEFF Research Database (Denmark)

    Brandbyge, Mads; Stokbro, Kurt; Taylor, Jeremy Philip

    2003-01-01

    We address the microscopic origin of the current-induced forces by analyzing results of first principles density functional calculations of atomic gold wires connected to two gold electrodes with different electrochemical potentials. We find that current induced forces are closely related...

  12. Electrode design optimization of lithium secondary batteries to enhance adhesion and deformation capabilities

    International Nuclear Information System (INIS)

    Jeong, Dongho; Lee, Jongsoo

    2014-01-01

    Safety, performance and lifetime of LSB (lithium secondary batteries) are affected by the adhesion of the active material to the electrode substance, and to the electrode deformation and the spring back limit in the electrode manufacturing process. This study explores the optimization process using decision tree analysis, an ANN (artificial neural network), and a multi-objective genetic algorithm. In the electrode design optimization, the objectives are to maximize the adhesion and to minimize the electrode deformation subjected to the allowable limit on the spring-back. Experimental data for use in design analysis and optimization is obtained via a measurement test. The decision tree analysis is first performed to extract major, effective parameters sensitive to adhesion force, electrode deformation and spring-back. The ANN-based approximate meta-models are then established for function approximations. The ANN-based causality analysis is further explored to determine dominant design variables for each of three design requirements for the optimization. A multi-objective optimization is finally conducted using ANN-based approximate meta-models. An optimized solution obtained from the numerical optimization process is compared with experimental data to verify the actual performance of the LSB in terms of physical and electro-chemical properties. - Highlights: • Electrode design for enhancing adhesion and electrode deformation performances. • Maximizing adhesion and minimizing deformation with allowable limit on spring-back. • Extraction of effective design parameters from data mining techniques. • Numerical optimization using experimental data of lithium secondary batteries. • Comparison of an optimized solution with an experimental result

  13. Investigations on effects of the hole size to fix electrodes and interconnection lines in polydimethylsiloxane

    Science.gov (United States)

    Behkami, Saber; Frounchi, Javad; Ghaderi Pakdel, Firouz; Stieglitz, Thomas

    2017-11-01

    Translational research in bioelectronics medicine and neural implants often relies on established material assemblies made of silicone rubber (polydimethylsiloxane-PDMS) and precious metals. Longevity of the compound is of utmost importance for implantable devices in therapeutic and rehabilitation applications. Therefore, secure mechanical fixation can be used in addition to chemical bonding mechanisms to interlock PDMS substrate and insulation layers with metal sheets for interconnection lines and electrodes. One of the best ways to fix metal lines and electrodes in PDMS is to design holes in electrode rims to allow for direct interconnection between top to bottom layer silicone. Hence, the best layouts and sizes of holes (up to 6) which provide sufficient stability against lateral and vertical forces have been investigated with a variety of numbers of hole in line electrodes, which are simulated and fabricated with different layouts, sizes and materials. Best stability was obtained with radii of 100, 72 and 62 µm, respectively, and a single central hole in aluminum, platinum and MP35N foil line electrodes of 400  ×  500 µm2 size and of thickness 20 µm. The study showed that the best hole size which provides line electrode immobility (of thickness less than 30 µm) within a central hole is proportional to reverse value of Young’s Modulus of the material used. Thus, an array of line electrodes was designed and fabricated to study this effect. Experimental results were compared with simulation data. Subsequently, an approximation curve was generated as design rule to propose the best radius to fix line electrodes according to the material thickness between 10 and 200 µm using PDMS as substrate material.

  14. Embedded Ultrathin Cluster Electrodes for Long-Term Recordings in Deep Brain Centers.

    Directory of Open Access Journals (Sweden)

    Leila Etemadi

    Full Text Available Neural interfaces which allow long-term recordings in deep brain structures in awake freely moving animals have the potential of becoming highly valuable tools in neuroscience. However, the recording quality usually deteriorates over time, probably at least partly due to tissue reactions caused by injuries during implantation, and subsequently micro-forces due to a lack of mechanical compliance between the tissue and neural interface. To address this challenge, we developed a gelatin embedded neural interface comprising highly flexible electrodes and evaluated its long term recording properties. Bundles of ultrathin parylene C coated platinum electrodes (N = 29 were embedded in a hard gelatin based matrix shaped like a needle, and coated with Kollicoat™ to retard dissolution of gelatin during the implantation. The implantation parameters were established in an in vitro model of the brain (0.5% agarose. Following a craniotomy in the anesthetized rat, the gelatin embedded electrodes were stereotactically inserted to a pre-target position, and after gelatin dissolution the electrodes were further advanced and spread out in the area of the subthalamic nucleus (STN. The performance of the implanted electrodes was evaluated under anesthesia, during 8 weeks. Apart from an increase in the median-noise level during the first 4 weeks, the electrode impedance and signal-to-noise ratio of single-units remained stable throughout the experiment. Histological postmortem analysis confirmed implantation in the area of STN in most animals. In conclusion, by combining novel biocompatible implantation techniques and ultra-flexible electrodes, long-term neuronal recordings from deep brain structures with no significant deterioration of electrode function were achieved.

  15. Selective oxidation of serotonin and norepinephrine over eriochrome cyanine R film modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Yao Hong; Li Shaoguang [Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350004 (China); Tang Yuhai [Institute of Analytical Sciences, Xi' an Jiaotong University, Xi' an 710061 (China); Chen Yan [Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350004 (China); Chen Yuanzhong [Fujian Institute of Hematology, The Affiliated Union Hospital of Fujian Medical University, Fuzhou 350001 (China)], E-Mail: chenyz@pub3.fz.fj.cn; Lin Xinhua [Department of Pharmaceutical Analysis, Faculty of Pharmacy, Fujian Medical University, Fuzhou 350004 (China)], E-mail: xhlin1963@sin.com

    2009-08-01

    A novel ECR-modified electrode is fabricated by electrodeposition of Eriochrome Cyanine R (ECR) at a glassy carbon (GC) electrode by cyclic voltammetry (CV) in double-distilled water. The characterization of the ECR film modified electrode is carried out by atomic force microscopy (AFM), infrared spectra (IR), spectroelectrochemistry and cyclic voltammetry. The results show that a slightly heterogeneous film formed on the surface of the modified electrode, and the calculated surface concentration of ECR is 2 x 10{sup -10} mol/cm{sup -2}. The ECR film modified GC electrode shows excellent electrocatalytic activities toward the oxidation of serotonin (5-HT) and norepinephrine (NE). Furthermore, the modified electrode can separately detect 5-HT and NE, even in the presence of 200-fold concentration of ascorbic acid (AA) and 25-fold concentration of uric acid (UA). Using differential pulse voltammetry (DPV), the peak currents of 5-HT and NE recorded in pH 7 solution are linearly dependent on their concentrations in the range of 0.05-5 {mu}M and 2-50 {mu}M, respectively. The limits of detection are 0.05 and 1.5 {mu}M for 5-HT and NE, respectively. The ECR film modified electrode can be stored stable for at least 1 week in 0.05 M PBS (pH 7) at 4 {sup o}C in a refrigerator. Owing to its excellent selectivity and sensitivity, the modified electrode could provide a promising tool for the simultaneous determination of 5-HT and NE in complex biosamples.

  16. APPLICATIONS OF A SINGLE CARBON ELECTRODE

    African Journals Online (AJOL)

    Preferred Customer

    Page 1 ... ABSTRACT: A single carbon electrode used with a common arc welder has been successfully used on steel to weld, to surface harden, to spot weld sheet, to pierce holes and to do simple brazing. ... applications: welding, spot welding, hole piercing, etc. The metal tube holding the carbon electrodes is banded with ...

  17. Low Energy Desalination Using Battery Electrode Deionization

    KAUST Repository

    Kim, Taeyoung

    2017-09-21

    New electrochemical technologies that use capacitive or battery electrodes are being developed to minimize energy requirements for desalinating brackish waters. When a pair of electrodes is charged in capacitive deionization (CDI) systems, cations bind to the cathode and anions bind to the anode, but high applied voltages (>1.2 V) result in parasitic reactions and irreversible electrode oxidation. In the battery electrode deionization (BDI) system developed here, two identical copper hexacyanoferrate (CuHCF) battery electrodes were used that release and bind cations, with anion separation occurring via an anion exchange membrane. The system used an applied voltage of 0.6 V, which avoided parasitic reactions, achieved high electrode desalination capacities (up to 100 mg-NaCl/g-electrode, 50 mM NaCl influent), and consumed less energy than CDI. Simultaneous production of desalinated and concentrated solutions in two channels avoided a two-cycle approach needed for CDI. Stacking additional membranes between CuHCF electrodes (up to three anion and two cation exchange membranes) reduced energy consumption to only 0.02 kWh/m3 (approximately an order of magnitude lower than values reported for CDI), for an influent desalination similar to CDI (25 mM decreased to 17 mM). These results show that BDI could be effective as a very low energy method for brackish water desalination.

  18. Synthesis of carbon nanotubes bridging metal electrodes

    International Nuclear Information System (INIS)

    Kotlar, M.; Vojs, M.; Marton, M.; Vesel, M.; Redhammer, R.

    2012-01-01

    In our work we demonstrate growth of carbon nanotubes that can conductively bridge the metal electrodes. The role of different catalysts was examined. Interdigitated metal electrodes are made from copper and we are using bimetal Al/Ni as catalyst for growth of carbon nanotubes. We are using this catalyst composition for growth of the single-walled carbon nanotube network. (authors)

  19. Reverse electrodialysis : evaluation of suitable electrode systems

    NARCIS (Netherlands)

    Veerman, J.; Saakes, M.; Metz, S. J.; Harmsen, G. J.

    Reverse electrodialysis (RED) is a method for directly extracting electrical energy from salinity gradients, especially from sea and river water. For the commercial implementation of RED, the electrode system is a key component. In this paper, novel electrode systems for RED were compared with

  20. Doped graphene electrodes for organic solar cells

    International Nuclear Information System (INIS)

    Park, Hyesung; Kim, Ki Kang; Bulovic, Vladimir; Kong, Jing; Rowehl, Jill A

    2010-01-01

    In this work graphene sheets grown by chemical vapor deposition (CVD) with controlled numbers of layers were used as transparent electrodes in organic photovoltaic (OPV) devices. It was found that for devices with pristine graphene electrodes, the power conversion efficiency (PCE) is comparable to their counterparts with indium tin oxide (ITO) electrodes. Nevertheless, the chances for failure in OPVs with pristine graphene electrodes are higher than for those with ITO electrodes, due to the surface wetting challenge between the hole-transporting layer and the graphene electrodes. Various alternative routes were investigated and it was found that AuCl 3 doping on graphene can alter the graphene surface wetting properties such that a uniform coating of the hole-transporting layer can be achieved and device success rate can be increased. Furthermore, the doping both improves the conductivity and shifts the work function of the graphene electrode, resulting in improved overall PCE performance of the OPV devices. This work brings us one step further toward the future use of graphene transparent electrodes as a replacement for ITO.

  1. Organic conductive films for semiconductor electrodes

    Science.gov (United States)

    Frank, Arthur J.

    1984-01-01

    According to the present invention, improved electrodes overcoated with conductive polymer films and preselected catalysts are provided. The electrodes typically comprise an inorganic semiconductor overcoated with a charge conductive polymer film comprising a charge conductive polymer in or on which is a catalyst or charge-relaying agent.

  2. Microneedle array electrode for human EEG recording.

    NARCIS (Netherlands)

    Lüttge, Regina; van Nieuwkasteele-Bystrova, Svetlana Nikolajevna; van Putten, Michel Johannes Antonius Maria; Vander Sloten, Jos; Verdonck, Pascal; Nyssen, Marc; Haueisen, Jens

    2009-01-01

    Microneedle array electrodes for EEG significantly reduce the mounting time, particularly by circumvention of the need for skin preparation by scrubbing. We designed a new replication process for numerous types of microneedle arrays. Here, polymer microneedle array electrodes with 64 microneedles,

  3. mwnts composite film modified glassy carbon electrode

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT: A poly p-aminosalicylic acid (Poly(p-ASA)) and multiwall carbon nanotubes. (MWCNTs) composite modified glassy carbon (GC) electrode was constructed by casting the MWNTs on the GC electrode surface followed by electropolymerization of the p-ASA on the MWCNTs/GCE. The electrochemical behaviours ...

  4. Nanometer-spaced electrodes with calibrated separation

    NARCIS (Netherlands)

    Kervennic, Y.V.; Van der Zant, H.S.J.; Morpurgo, A.F.; Gurevich, L.; Kouwenhoven, L.P.

    2002-01-01

    We have fabricated pairs of platinum electrodes with separation between 20 and 3.5 nm. Our technique combines electron beam lithography and chemical electrodeposition. We show that the measurement of the conductance between the two electrodes through the electrolyte provides an accurate and

  5. Substitution of thoriated tungsten electrodes in Switzerland

    International Nuclear Information System (INIS)

    Kunz, H.; Piller, G.

    2006-01-01

    Thoriated tungsten electrodes are frequently used for inert gas welding (TIG/WIG). The use of these electrodes can lead to doses which are well above the limit for the general population (1mSv/year). This has been shown by different investigations, for example from the ''Berufsgenossenschaft''. With these findings in mind, the regulatory authorities (Swiss Federal Office of Public Health (SFOPH) and Swiss National Accident Insurance Association (Suva)) started in 1999 to examine the justification of thoriated tungsten electrodes and a possible substitution with products containing no radioactive material. Up to this time, the use of thoriated tungsten electrodes could be justified since no thorium-free products leading to comparable results were available on the market. This was also the reason why the SFOPH approved several types of these electrodes. Discussions with formation centers for welding and inquiries made at welding shops, trading companies and producers showed that in the mean-time thorium-free products with comparable welding specifications and results became available on the market. Since the 1 January 2004, thoriated tungsten electrodes can only be used if the user has obtained the corresponding license from the SFOPH. The use of thoriated tungsten electrodes is thus not completely forbidden, but very strict conditions have to be fulfilled. Up to now and due to the involvement of the relevant partners, the substitution process has not met any problem. Neither trading companies nor users made any opposition and no request for obtaining a license for thoriated tungsten electrodes was made. (orig.)

  6. Finite element analysis on factors influencing the clamping force in an electrostatic chuck

    International Nuclear Information System (INIS)

    Wang Xingkuo; Yang Yiyong; Cheng Jia; Wang Kesheng; Sun Yuchun; Cao Minglu; Ji Linhong

    2014-01-01

    As one of the core components of IC manufacturing equipment, the electrostatic chuck (ESC) has been widely applied in semiconductor processing such as etching, PVD and CVD. The clamping force of the ESC is one of the most important technical indicators. A multi-physics simulation software COMSOL is used to analyze the factors influencing the clamping force. The curves between the clamping force and the main parameters such as DC voltage, electrode thickness, electrode radius, dielectric thickness and helium gap are obtained. Moreover, the effects of these factors on the clamping force are investigated by means of orthogonal experiments. The results show that the factors can be ranked in order of voltage, electrode radius, helium gap and dielectric thickness according to their importance, which may offer certain reference for the design of ESCs. (semiconductor devices)

  7. Bipolar Electrode Sample Preparation Devices

    Science.gov (United States)

    Wang, Yi (Inventor); Song, Hongjun (Inventor); Pant, Kapil (Inventor)

    2017-01-01

    An analyte selection device can include: a body defining a fluid channel having a channel inlet and channel outlet; a bipolar electrode (BPE) between the inlet and outlet; one of an anode or cathode electrically coupled with the BPE on a channel inlet side of the BPE and the other of the anode or cathode electrically coupled with the BPE on a channel outlet side of the BPE; and an electronic system operably coupled with the anode and cathode so as to polarize the BPE. The fluid channel can have any shape or dimension. The channel inlet and channel outlet can be longitudinal or lateral with respect to the longitudinal axis of the channel. The BPE can be any metallic member, such as a flat plate on a wall or mesh as a barrier BPE. The anode and cathode can be located at a position that polarizes the BPE.

  8. Carbonaceous electrode materials for supercapacitors.

    Science.gov (United States)

    Hao, Long; Li, Xianglong; Zhi, Linjie

    2013-07-26

    Supercapacitors have been widely studied around the world in recent years, due to their excellent power density and long cycle life. As the most frequently used electrode materials for supercapacitors, carbonaceous materials attract more and more attention. However, their relatively low energy density still holds back the widespread application. Up to now, various strategies have been developed to figure out this problem. This research news summarizes the recent advances in improving the supercapacitor performance of carbonaceous materials, including the incorporation of heteroatoms and the pore size effect (subnanopores' contribution). In addition, a new class of carbonaceous materials, porous organic networks (PONs) has been managed into the supercapacitor field, which promises great potential in not only improving the supercapacitor performances, but also unraveling the related mechanisms. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Conducting polymer coated neural recording electrodes

    Science.gov (United States)

    Harris, Alexander R.; Morgan, Simeon J.; Chen, Jun; Kapsa, Robert M. I.; Wallace, Gordon G.; Paolini, Antonio G.

    2013-02-01

    Objective. Neural recording electrodes suffer from poor signal to noise ratio, charge density, biostability and biocompatibility. This paper investigates the ability of conducting polymer coated electrodes to record acute neural response in a systematic manner, allowing in depth comparison of electrochemical and electrophysiological response. Approach. Polypyrrole (Ppy) and poly-3,4-ethylenedioxythiophene (PEDOT) doped with sulphate (SO4) or para-toluene sulfonate (pTS) were used to coat iridium neural recording electrodes. Detailed electrochemical and electrophysiological investigations were undertaken to compare the effect of these materials on acute in vivo recording. Main results. A range of charge density and impedance responses were seen with each respectively doped conducting polymer. All coatings produced greater charge density than uncoated electrodes, while PEDOT-pTS, PEDOT-SO4 and Ppy-SO4 possessed lower impedance values at 1 kHz than uncoated electrodes. Charge density increased with PEDOT-pTS thickness and impedance at 1 kHz was reduced with deposition times up to 45 s. Stable electrochemical response after acute implantation inferred biostability of PEDOT-pTS coated electrodes while other electrode materials had variable impedance and/or charge density after implantation indicative of a protein fouling layer forming on the electrode surface. Recording of neural response to white noise bursts after implantation of conducting polymer-coated electrodes into a rat model inferior colliculus showed a general decrease in background noise and increase in signal to noise ratio and spike count with reduced impedance at 1 kHz, regardless of the specific electrode coating, compared to uncoated electrodes. A 45 s PEDOT-pTS deposition time yielded the highest signal to noise ratio and spike count. Significance. A method for comparing recording electrode materials has been demonstrated with doped conducting polymers. PEDOT-pTS showed remarkable low fouling during

  10. Lithium-aluminum-iron electrode composition

    Science.gov (United States)

    Kaun, Thomas D.

    1979-01-01

    A negative electrode composition is presented for use in a secondary electrochemical cell. The cell also includes an electrolyte with lithium ions such as a molten salt of alkali metal halides or alkaline earth metal halides that can be used in high-temperature cells. The cell's positive electrode contains a 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 in an alloy of aluminum-iron. Various binary and ternary intermetallic phases of lithium, aluminum and iron are formed. The lithium within the intermetallic phase of Al.sub.5 Fe.sub.2 exhibits increased activity over that of lithium within a lithium-aluminum alloy to provide an increased cell potential of up to about 0.25 volt.

  11. Emerging Novel Metal Electrodes for Photovoltaic Applications.

    Science.gov (United States)

    Lu, Haifei; Ren, Xingang; Ouyang, Dan; Choy, Wallace C H

    2018-04-01

    Emerging novel metal electrodes not only serve as the collector of free charge carriers, but also function as light trapping designs in photovoltaics. As a potential alternative to commercial indium tin oxide, transparent electrodes composed of metal nanowire, metal mesh, and ultrathin metal film are intensively investigated and developed for achieving high optical transmittance and electrical conductivity. Moreover, light trapping designs via patterning of the back thick metal electrode into different nanostructures, which can deliver a considerable efficiency improvement of photovoltaic devices, contribute by the plasmon-enhanced light-mattering interactions. Therefore, here the recent works of metal-based transparent electrodes and patterned back electrodes in photovoltaics are reviewed, which may push the future development of this exciting field. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Investigation of Imbalanced Activated Carbon Electrode Supercapacitors

    Directory of Open Access Journals (Sweden)

    Tieshi He

    2015-01-01

    Full Text Available Imbalanced supercapacitor was constructed by using various ratio of activated carbon (AC of positive to negative electrode. The electrochemical behavior of imbalanced supercapacitor was investigated using 1.0 M spiro-(1,1′-bipyrrolidinium tetrafluoroborate electrolyte in propylene carbonate. The results showed that there are some factors that influenced the imbalanced supercapacitor with different AC ratio of positive to negative electrode, the utilization of AC, electrode potential distribution, and life cycle. The imbalanced supercapacitor with an AC weight ratio of 80 : 120 of positive to negative electrode has an average potential distribution in each electrode, and it revealed the best electrochemical performance: specific capacitor was 39.6 F·g−1, while the charge-discharge efficiency was 97.2% after 2000 life cycle tests.

  13. Pierce electrodes for a multigap accelerating system

    International Nuclear Information System (INIS)

    Davydenko, V.I.; Ivanov, A.A.; Kotelnikov, I.A.; Tiunov, M.A.

    2007-01-01

    A well-known Pierce's solution that allows to focus a beam of charged particles using properly shaped electrodes outside the beam is generalized to the case of multigap accelerating system. Simple parametric formulae for Pierce electrodes are derived for an accelerating system with current density, limited either by space charge or by emitting property of the cathode. As an example of general approach, Pierce electrodes shape is analyzed for a system with two accelerating gaps. It is shown that precise Pierce's solution exists if acceleration rate within second gap is lower than within first gap. In the opposite case quasi-Pierce solution can be implemented using non-equipotential electrode between the gaps, and guidelines, based on numerical simulations, for the design of equipotential focusing electrodes are given

  14. Kelvin probe force microscopy in liquid using electrochemical force microscopy

    Directory of Open Access Journals (Sweden)

    Liam Collins

    2015-01-01

    Full Text Available Conventional closed loop-Kelvin probe force microscopy (KPFM has emerged as a powerful technique for probing electric and transport phenomena at the solid–gas interface. The extension of KPFM capabilities to probe electrostatic and electrochemical phenomena at the solid–liquid interface is of interest for a broad range of applications from energy storage to biological systems. However, the operation of KPFM implicitly relies on the presence of a linear lossless dielectric in the probe–sample gap, a condition which is violated for ionically-active liquids (e.g., when diffuse charge dynamics are present. Here, electrostatic and electrochemical measurements are demonstrated in ionically-active (polar isopropanol, milli-Q water and aqueous NaCl and ionically-inactive (non-polar decane liquids by electrochemical force microscopy (EcFM, a multidimensional (i.e., bias- and time-resolved spectroscopy method. In the absence of mobile charges (ambient and non-polar liquids, KPFM and EcFM are both feasible, yielding comparable contact potential difference (CPD values. In ionically-active liquids, KPFM is not possible and EcFM can be used to measure the dynamic CPD and a rich spectrum of information pertaining to charge screening, ion diffusion, and electrochemical processes (e.g., Faradaic reactions. EcFM measurements conducted in isopropanol and milli-Q water over Au and highly ordered pyrolytic graphite electrodes demonstrate both sample- and solvent-dependent features. Finally, the feasibility of using EcFM as a local force-based mapping technique of material-dependent electrostatic and electrochemical response is investigated. The resultant high dimensional dataset is visualized using a purely statistical approach that does not require a priori physical models, allowing for qualitative mapping of electrostatic and electrochemical material properties at the solid–liquid interface.

  15. Ionization detector, electrode configuration and single polarity charge detection method

    Science.gov (United States)

    He, Z.

    1998-07-07

    An ionization detector, an electrode configuration and a single polarity charge detection method each utilize a boundary electrode which symmetrically surrounds first and second central interlaced and symmetrical electrodes. All of the electrodes are held at a voltage potential of a first polarity type. The first central electrode is held at a higher potential than the second central or boundary electrodes. By forming the first and second central electrodes in a substantially interlaced and symmetrical pattern and forming the boundary electrode symmetrically about the first and second central electrodes, signals generated by charge carriers are substantially of equal strength with respect to both of the central electrodes. The only significant difference in measured signal strength occurs when the charge carriers move to within close proximity of the first central electrode and are received at the first central electrode. The measured signals are then subtracted and compared to quantitatively measure the magnitude of the charge. 10 figs.

  16. Analysis of polypyrrole-coated stainless steel electrodes

    Indian Academy of Sciences (India)

    Analysis of polypyrrole-coated stainless steel electrodes - Estimation of specific ... is carried out on stainless steel electrodes using -toluene sulphonic acid. ... The feasibility of the electrode for supercapacitor applications is investigated.

  17. Current-Induced Forces and Hot Spots in Biased Nanojunctions

    DEFF Research Database (Denmark)

    Lu, Jing Tao; Christensen, Rasmus Bjerregaard; Wang, Jian-Sheng

    2015-01-01

    We investigate theoretically the interplay of current-induced forces (CIFs), Joule heating, and heat transport inside a current-carrying nanoconductor. We find that the CIFs, due to the electron-phonon coherence, can control the spatial heat dissipation in the conductor. This yields a significant...... asymmetric concentration of excess heating (hot spot) even for a symmetric conductor. When coupled to the electrode phonons, CIFs drive different phonon heat flux into the two electrodes. First-principles calculations on realistic biased nanojunctions illustrate the importance of the effect....

  18. 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

  19. 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.

  20. Novel graphene-like electrodes for capacitive deionization.

    Science.gov (United States)

    Li, Haibo; Zou, Linda; Pan, Likun; Sun, Zhuo

    2010-11-15

    Capacitive deionization (CDI) is a novel technology that has been developed for removal of charged ionic species from salty water, such as salt ions. The basic concept of CDI, as well as electrosorption, is to force charged ions toward oppositely polarized electrodes through imposing a direct electric field to form a strong electrical double layer and hold the ions. Once the electric field disappears, the ions are instantly released back to the bulk solution. CDI is an alternative low-energy consumption desalination technology. Graphene-like nanoflakes (GNFs) with relatively high specific surface area have been prepared and used as electrodes for capacitive deionization. The GNFs were synthesized by a modified Hummers' method using hydrazine for reduction. They were characterized by atomic force microscopy, N2 adsorption at 77 K and electrochemical workstation. It was found that the ratio of nitric acid and sulfuric acid plays a vital role in determining the specific surface area of GNFs. Its electrosorption performance was much better than commercial activated carbon (AC), suggesting a great potential in capacitive deionisation application. Further, the electrosorptive performance of GNFs electrodes with different bias potentials, flow rates and ionic strengths were measured and the electrosorption isotherm and kinetics were investigated. The results showed that GNFs prepared by this process had the specific surface area of 222.01 m²/g. The specific electrosorptive capacity of the GNFs was 23.18 µmol/g for sodium ions (Na+) when the initial concentration was at 25 mg/L, which was higher than that of previously reported data using graphene and AC under the same experimental condition. In addition, the equilibrium electrosorption capacity was determined as 73.47 µmol/g at 2.0 V by fitting data through the Langmuir isotherm, and the rate constant was found to be 1.01 min⁻¹ by fitting data through pseudo first-order adsorption. The results suggested that the

  1. Lithium battery electrodes with ultra-thin alumina coatings

    Science.gov (United States)

    Se-Hee, Lee; George, Steven M.; Cavanagh, Andrew S.; Yoon Seok, Jung; Dillon, Anne C.

    2015-11-24

    Electrodes for lithium batteries are coated via an atomic layer deposition process. The coatings can be applied to the assembled electrodes, or in some cases to particles of electrode material prior to assembling the particles into an electrode. The coatings can be as thin as 2 .ANG.ngstroms thick. The coating provides for a stable electrode. Batteries containing the electrodes tend to exhibit high cycling capacities.

  2. High aspect ratio silver grid transparent electrodes using UV embossing process

    Directory of Open Access Journals (Sweden)

    Dong Jin Kim

    2017-10-01

    Full Text Available This study presents a UV embossing process to fabricate high aspect ratio silver grid transparent electrodes on a polymer film. Transparent electrodes with a high optical transmittance (93 % and low sheet resistance (4.6 Ω/sq were fabricated without any high temperature or vacuum processes. The strong adhesion force between the UV resin and the silver ink enables the fabrication of silver microstructures with an aspect ratio higher than 3. The high aspect ratio results in a low sheet resistance while maintaining a high optical transmittance. Multi-layer transparent electrodes were fabricated by repeating the proposed UV process. Additionally, a large-area of 8-inch touch panel was fabricated with the proposed UV process. The proposed UV process is a relatively simple and low cost process making it suitable for large-area production as well as mass production.

  3. Electrochemical functionalization of glassy carbon electrode by reduction of diazonium cations in protic ionic liquid

    International Nuclear Information System (INIS)

    Shul, Galyna; Ruiz, Carlos Alberto Castro; Rochefort, Dominic; Brooksby, Paula A.; Bélanger, Daniel

    2013-01-01

    Protic ionic liquid based on 2-methoxypyridine and trifluoroacetic acid was used as electrolyte for the functionalization of a glassy carbon electrode surface by electrochemical reduction of in situ generated 4-chlorobenzene diazonium and 4-nitrobenzene diazonium cations. The diazonium cations were synthesized in an electrochemical cell by reaction of the corresponding amines with NaNO 2 dissolved in protic ionic liquid. The resulting electrografted organic layers exhibit similar properties to those layers obtained by the derivatization from isolated diazonium salts dissolved in protic ionic liquid. Functionalized glassy carbon electrode surfaces were characterized by cyclic voltammetry, Fourier transform infrared and X-ray photoelectron spectroscopies. Atomic force microscopy thickness measurements revealed that, in our experimental conditions, the use of protic ionic liquid led to the formation of film with a thickness of about 1.5 nm. It is also demonstrated that the nitrobenzene chemisorbed on glassy carbon electrode or dissolved in protic ionic liquid undergoes electrochemical conversion to hydroxyaminobenzene

  4. Graphene quantum dot modified glassy carbon electrode for the determination of doxorubicin hydrochloride in human plasma

    Directory of Open Access Journals (Sweden)

    Nastaran Hashemzadeh

    2016-08-01

    Full Text Available Low toxic graphene quantum dot (GQD was synthesized by pyrolyzing citric acid in alkaline solution and characterized by ultraviolet--visible (UV–vis spectroscopy, X-ray diffraction (XRD, atomic force microscopy (AFM, spectrofluorimetery and dynamic light scattering (DLS techniques. GQD was used for electrode modification and electro-oxidation of doxorubicin (DOX at low potential. A substantial decrease in the overvoltage (−0.56 V of the DOX oxidation reaction (compared to ordinary electrodes was observed using GQD as coating of glassy carbon electrode (GCE. Differential pulse voltammetry was used to evaluate the analytical performance of DOX in the presence of phosphate buffer solution (pH 4.0 and good limit of detection was obtained by the proposed sensor. Such ability of GQD to promote the DOX electron-transfer reaction suggests great promise for its application as an electrochemical sensor.

  5. Microscopy studies on pronton exchange membrane fuel cell electrodes with different ionomer contents

    DEFF Research Database (Denmark)

    Ma, Shuang; Solterbeck, Claus Henning; Odgaard, Madeleine

    2009-01-01

    of the electrode was well displayed in the topography and phase images. The particle and pore size (Z) distributions showed the most frequent values at 30-40 nm and 20-30 nm, respectively. The particle size corresponds to the size of the carbon support for the platinum catalyst. Catalyst agglomeration was observed......Proton Exchange Membrane (PEM) fuel cell electrodes with different ionomer contents were studied with various microscopic techniques. The morphology and surface potential were examined by Atomic Force Microscopy (AFM) and Kelvin Probe Microscopy (KPM), respectively. The particulate nature...... in high ionomer content electrodes. The surface potential images showed distinct difference to the topography images. The overall grain size was seen to increase, the pore volume to decrease, the surface roughness to decrease, and the surface potential variation to increase with the increase of ionomer...

  6. Electrochemical behavior of adrenaline at the carbon atom wire modified electrode

    Energy Technology Data Exchange (ETDEWEB)

    Xue Kuanhong [Chemistry Department, Nanjing Normal University, Jiangsu Engineering Research Center for Bio-medical Function Materials, 122 NingHai Road, Nanjing, JiangSu 210097 (China)], E-mail: khxue@njnu.edu.cn; Liu Jiamei [Chemistry Department, Nanjing Normal University, Jiangsu Engineering Research Center for Bio-medical Function Materials, 122 NingHai Road, Nanjing, JiangSu 210097 (China); Wei Ribing [Chemistry Department, Nanjing Normal University, Jiangsu Engineering Research Center for Bio-medical Function Materials, 122 NingHai Road, Nanjing, JiangSu 210097 (China); Chen Shaopeng [Chemistry Department, Nanjing Normal University, Jiangsu Engineering Research Center for Bio-medical Function Materials, 122 NingHai Road, Nanjing, JiangSu 210097 (China)

    2006-09-11

    Electrochemical behavior of adrenaline at an electrode modified by carbon atom wires (CAWs), a new material, was investigated by cyclic voltammetry combined with UV-vis spectrometry, and forced convection method. As to the electrochemical response of redox of adrenaline/adrenalinequinone couple in 0.50 M H{sub 2}SO{sub 4}, at a nitric acid treated CAW modified electrode, the anodic and cathodic peak potentials E {sub pa} and E {sub pc} shifted by 87 mV negatively and 139 mV in the positive direction, respectively, and standard heterogeneous rate constant k {sup 0} increased by 16 times compared to the corresponding bare electrode, indicating the extraordinary activity of CAWs in electrocatalysis for the process.

  7. Electrochemical behavior of adrenaline at the carbon atom wire modified electrode

    Science.gov (United States)

    Xue, Kuan-Hong; Liu, Jia-Mei; Wei, Ri-Bing; Chen, Shao-Peng

    2006-09-01

    Electrochemical behavior of adrenaline at an electrode modified by carbon atom wires (CAWs), a new material, was investigated by cyclic voltammetry combined with UV-vis spectrometry, and forced convection method. As to the electrochemical response of redox of adrenaline/adrenalinequinone couple in 0.50 M H 2SO 4, at a nitric acid treated CAW modified electrode, the anodic and cathodic peak potentials Epa and Epc shifted by 87 mV negatively and 139 mV in the positive direction, respectively, and standard heterogeneous rate constant k0 increased by 16 times compared to the corresponding bare electrode, indicating the extraordinary activity of CAWs in electrocatalysis for the process.

  8. Electrochemical behavior of adrenaline at the carbon atom wire modified electrode

    International Nuclear Information System (INIS)

    Xue Kuanhong; Liu Jiamei; Wei Ribing; Chen Shaopeng

    2006-01-01

    Electrochemical behavior of adrenaline at an electrode modified by carbon atom wires (CAWs), a new material, was investigated by cyclic voltammetry combined with UV-vis spectrometry, and forced convection method. As to the electrochemical response of redox of adrenaline/adrenalinequinone couple in 0.50 M H 2 SO 4 , at a nitric acid treated CAW modified electrode, the anodic and cathodic peak potentials E pa and E pc shifted by 87 mV negatively and 139 mV in the positive direction, respectively, and standard heterogeneous rate constant k 0 increased by 16 times compared to the corresponding bare electrode, indicating the extraordinary activity of CAWs in electrocatalysis for the process

  9. Simple fabrication of active electrodes using direct laser transference

    International Nuclear Information System (INIS)

    Cavallo, P.; Coneo Rodriguez, R.; Broglia, M.; Acevedo, D.F.; Barbero, C.A.

    2014-01-01

    Highlights: •Electroactive materials can be transferred using a single pulse of laser light. •The transfer is made in air using a 6 ns pulse of Nd-YAG laser (532 or 1064 nm). •Conducting polymers films can be transferred maintaining the electroactivity. •Conducting polymer multilayers can be deposited using successive pulses. •Metallic (Au, Pt) transferred micro/nanoparticles are electrocatalytic. -- Abstract: Direct laser transference (DLT) method is applied to obtain electrodes modified with thin films of conducting polymers (CPs) or catalytic metals. A short (6–10 ns) pulse of laser light (second harmonic of Nd-YAG Laser, λ = 532 nm) is shined on the backside of a thin (<200 nm) film of the material to be transferred, which is deposited on a transparent substrate. The illuminated region heats up and the material (conducting polymer or metal) is thermally transferred to a solid target placed at short distance in air. In that ways, CPs are transferred onto polypropylene, glass, indium doped tin oxide (ITO), glassy carbon and gold films. In the same manner, electrocatalytic metals (platinum or gold) are transferred onto conductive substrates (glassy carbon or ITO films on glass). The films have been characterized by scanning electron microscopy, cyclic voltammetry, atomic force microscopy, UV-visible and Fourier Transform Infrared spectroscopies. The chemical, electrical and redox properties of the polymeric materials transferred remain unaltered after the transfer. Moreover, CP multilayers can be built applying DLT several times onto the same substrate. Besides polyaniline, it is shown that it is also possible to transfer functionalized polyanilines. The electrode modified with transferred Pt shows electrocatalytic activity toward methanol oxidation while ferricyanide shows a quasireversible behavior on electrodes modified with transferred Au. The method is simple and fast, works in air without complex environmental conditions and can produce active

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

    DEFF Research Database (Denmark)

    Jacobsen, Torben

    the equivalent capacity, $C^{1/\\alpha}$, plotted against the contact area during an experimental period of 2 weeks. The contact area is calculated from the electrolyte resistance as $A=1/(4\\pi(\\sigma R_{YSZ})^2)$. After the electrode has been allowed to touch the electrolyte an increasing capacity proportional......$C in air. The different perturbations are indicated on the graph by numbers. 1-2\\hfill\\parbox[t]{7.3cm}{Thermal cycle at equilibrium. Determination of activation energies.} 3-4\\hfill\\parbox[t]{7.3cm}{ Potential step to -0.150\\,V for 5 hours. Activation.} 5-6\\hfill\\parbox[t]{7.3cm}{ Potential staircase 0...... $\\rightarrow$ -0.150 $\\rightarrow$ 0.050$\\rightarrow$ -0.150 0V. Potential dependence of parameters.} 6-7\\hfill\\parbox[t]{7.3cm}{ Potential step to 0.050\\,V for 4 hours. Activation.} 8-9\\hfill\\parbox[t]{7.3cm}{ As 5-6.} 9-10\\hfill\\parbox[t]{7.3cm}{Thermal cycle at -0.150\\,V. Activation energies.} 11-12\\hfill...

  11. Nickel hydrogen bipolar battery electrode design

    Science.gov (United States)

    Puglisi, V. J.; Russell, P.; Verrier, D.; Hall, A.

    1985-01-01

    The preferred approach of the NASA development effort in nickel hydrogen battery design utilizes a bipolar plate stacking arrangement to obtain the required voltage-capacity configuration. In a bipolar stack, component designs must take into account not only the typical design considerations such as voltage, capacity and gas management, but also conductivity to the bipolar (i.e., intercell) plate. The nickel and hydrogen electrode development specifically relevant to bipolar cell operation is discussed. Nickel oxide electrodes, having variable type grids and in thicknesses up to .085 inch are being fabricated and characterized to provide a data base. A selection will be made based upon a system level tradeoff. Negative (hydrpogen) electrodes are being screened to select a high performance electrode which can function as a bipolar electrode. Present nickel hydrogen negative electrodes are not capable of conducting current through their cross-section. An electrode was tested which exhibits low charge and discharge polarization voltages and at the same time is conductive. Test data is presented.

  12. Electrode systems for in situ vitrification

    Science.gov (United States)

    Buelt, James L.; Carter, John G.; Eschbach, Eugene A.; FitzPatrick, Vincent F.; Koehmstedt, Paul L.; Morgan, William C.; Oma, Kenton H.; Timmerman, Craig L.

    1990-01-01

    An electrode comprising a molybdenum rod is received within a conductive collar formed of graphite. The molybdenum rod and the graphite collar may be physically joined at the bottom. A pair of such electrodes are placed in soil containing buried waste material and an electric current is passed therebetween for vitrifying the soil. The graphite collar enhances the thermal conductivity of the combination, bringing heat to the surface, and preventing formation of a cold cap of material above the ground surface. The annulus between the molybdenum rod electrode and the graphite collar is suitably filled with a conductive ceramic powder that sinters upon the molybdenum rod, protecting the same from oxidation as graphite material is consumed, or a metal powder which liquefies at operating temperatures. The center of the molybdenum rod, used with a collar of separately, can be hollow and filled with a powdered metal, such as copper, which liquefies at operating temperatures. Connection to electrodes can be provided below ground level to avoid open circuit due to electrode deterioration, or sacrificial electrodes may be employed when operation is started. Outboard electrodes cna be utilized to square up a vitrified area.

  13. Rational design of new electrodes for electrochemotherapy.

    Science.gov (United States)

    Spugnini, E P; Citro, G; Porrello, A

    2005-06-01

    Electrochemotherapy associates the local delivery of anticancer drugs with the administration of permeabilizing electric pulses that support the antiblastic action. The basic instrumentation for this therapy is constituted by a pulse generator and various specific electrodes. While many efforts have been profuse by researchers in this field to obtain the standardization of the pulse generating equipment over the past 15 years, the delivery apparatus still needs refinements in order to reach most of the body districts, to control the homogeneity and stability of the electric fields and to further reduce morbidity. With the aim to develop innovative electrodes able to satisfy, at least partially, these requirements, extensive studies on pet patients with spontaneous neoplasms have been conducted, leading to the manufacturing of several different prototypes. In this paper we discuss the rationale of 11 different electrodes, briefly summarize the results obtained and their experimental validation, also presenting five paradigmatic clinical cases. In particular, it is shown that the caliper electrodes are more suited for the treatment of cutaneous and subcutaneous lesions, while the needle arrays are more efficacious in intraoperative settings. Furthermore, relevant peculiarities of unipolar electrodes are examined with a particular focus on the irregular current paths that they produce and on the potentialities of this feature. Remarkably, the decrease of the steric encumbrance turned out to be a stronger factor in electrode design than the containment of the total number of electric fields covered in serial ECT sessions. In the conclusions, perspectives and new challenges of electrode design for electrochemotherapy are illustrated.

  14. 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.

  15. How the condition of occlusal support affects the back muscle force and masticatory muscle activity?

    OpenAIRE

    石岡, 克; 河野, 正司; Ishioka, Masaru; Kohno, Shoji

    2002-01-01

    This study was conducted to determine how the condition of occlusal support affects the back muscle force and masticatory muscle activity. Two groups of subjects were enlisted: sport-trained group and normal group. While electrodes of the electromyography (EMG) were attached to the surface of the masticatory muscles, each subject's back muscle force was recorded during upper body stretching using a back muscle force-measuring device. The task was performed under four different occlusal suppor...

  16. Interfacial force measurements using atomic force microscopy

    NARCIS (Netherlands)

    Chu, L.

    2018-01-01

    Atomic Force Microscopy (AFM) can not only image the topography of surfaces at atomic resolution, but can also measure accurately the different interaction forces, like repulsive, adhesive and lateral existing between an AFM tip and the sample surface. Based on AFM, various extended techniques have

  17. Cyanex based uranyl sensitive polymeric membrane electrodes.

    Science.gov (United States)

    Badr, Ibrahim H A; Zidan, W I; Akl, Z F

    2014-01-01

    Novel uranyl selective polymeric membrane electrodes were prepared using three different low-cost and commercially available Cyanex extractants namely, bis(2,4,4-trimethylpentyl) phosphinic acid [L1], bis(2,4,4-trimethylpentyl) monothiophosphinic acid [L2] and bis(2,4,4-trimethylpentyl) dithiophosphinic acid [L3]. Optimization and performance characteristics of the developed Cyanex based polymer membrane electrodes were determined. The influence of membrane composition (e.g., amount and type of ionic sites, as well as type of plasticizer) on potentiometric responses of the prepared membrane electrodes was studied. Optimized Cyanex-based membrane electrodes exhibited Nernstian responses for UO₂(2+) ion over wide concentration ranges with fast response times. The optimized membrane electrodes based on L1, L2 and L3 exhibited Nernstian responses towards uranyl ion with slopes of 29.4, 28.0 and 29.3 mV decade(-1), respectively. The optimized membrane electrodes based on L1-L3 showed detection limits of 8.3 × 10(-5), 3.0 × 10(-5) and 3.3 × 10(-6) mol L(-1), respectively. The selectivity studies showed that the optimized membrane electrodes exhibited high selectivity towards UO₂(2+) ion over large number of other cations. Membrane electrodes based on L3 exhibited superior potentiometric response characteristics compared to those based on L1 and L2 (e.g., widest linear range and lowest detection limit). The analytical utility of uranyl membrane electrodes formulated with Cyanex extractant L3 was demonstrated by the analysis of uranyl ion in different real samples for nuclear safeguards verification purposes. The results obtained using direct potentiometry and flow-injection methods were compared with those measured using the standard UV-visible and inductively coupled plasma spectroscopic methods. © 2013 Published by Elsevier B.V.

  18. Insulating electrodes: a review on biopotential front ends for dielectric skin–electrode interfaces

    International Nuclear Information System (INIS)

    Spinelli, Enrique; Haberman, Marcelo

    2010-01-01

    Insulating electrodes, also known as capacitive electrodes, allow acquiring biopotentials without galvanic contact with the body. They operate with displacement currents instead of real charge currents, and the electrolytic electrode–skin interface is replaced by a dielectric film. The use of insulating electrodes is not the end of electrode interface problems but the beginning of new ones: coupling capacitances are of the order of pF calling for ultra-high input impedance amplifiers and careful biasing, guarding and shielding techniques. In this work, the general requirements of front ends for capacitive electrodes are presented and the different contributions to the overall noise are discussed and estimated. This analysis yields that noise bounds depend on features of the available devices as current and voltage noise, but the final noise level also depends on parasitic capacitances, requiring a careful shield and printed circuit design. When the dielectric layer is placed on the skin, the present-day amplifiers allow achieving noise levels similar to those provided by wet electrodes. Furthermore, capacitive electrode technology allows acquiring high quality ECG signals through thin clothes. A prototype front end for capacitive electrodes was built and tested. ECG signals were acquired with these electrodes in direct contact with the skin and also through cotton clothes 350 µm thick. They were compared with simultaneously acquired signals by means of wet electrodes and no significant differences were observed between both output signals

  19. Effect of Particle Size on Electrode Potential and Thermodynamics of Nanoparticles Electrode in Theory and Experiment

    International Nuclear Information System (INIS)

    Yunfeng, Yang; Yongqiang, Xue; Zixiang, Cui; Miaozhi, Zhao

    2014-01-01

    The particle size of electrode materials has a significant influence on the standard electrode potential and the thermodynamic properties of electrode reactions. In this paper, the size-dependent electrochemical thermodynamics has been theoretically investigated and successfully deduced electrochemical thermodynamics equations for nanoparticles electrode. At the same time, the electrode potential and thermodynamical properties of Ag 2 O/Ag nanoparticles electrode constructed by the solid and spherical Ag 2 O nanoparticles with different sizes further testified that the particle size of nanoparticles has a significant effect on electrochemical thermodynamics. The results show that the electrode potential depends on that of the smallest nanoparticle in a nanoparticles electrode which consisted of different particle sizes of nano-Ag 2 O. When the size of Ag 2 O nanoparticles reduces, the standard electrode potentials and the equilibrium constants of the corresponding electrode reactions increase, and the temperature coefficient, the mole Gibbs energy change, the mole enthalpy change and the mole entropy change decrease. Moreover, these physical quantities are all linearly related with the reciprocal of average particle size (r > 10 nm). The experimental regularities coincide with the theoretical equations

  20. Investigation of interaction between silver oxide electrode and separator hydrated cellulose film in silver-cadmium accumulators

    International Nuclear Information System (INIS)

    Molotkova, E.N.; Yarochkina, E.N.

    1975-01-01

    Oxidation-reduction interaction of the oxysilver electrode with hydrocellulose film during storing charged silver-cadmium accumulators. It was demonstrated that accumulator electric characteristics durinq storing are linearly depending on the capacity of this hydrocellulose film to interact with silver oxide: the more silver is absorbed by film the quicker is the decreasing of the electromotive force and capacity of the accumulators. Preservation of the silver electrode capacity in the silver-cadmium accumulators is determined first of all by hydrocellulose separation film properties and especially by film layer adjacent to positive electrode. The more inert film layer is, regarding to silver oxide in the electrolite, the slower is dissolution of the electrode and also decompousing speed of AgO, the longer is the accumulator preservation time

  1. 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.

  2. 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...

  3. Conducting polymer electrodes for gel electrophoresis.

    Science.gov (United States)

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D

    2014-01-01

    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.

  4. Redox properties of phenosafranine at zeolite-modified electrodes-Effect of surface modification and solution pH

    International Nuclear Information System (INIS)

    Easwaramoorthi, S.; Natarajan, P.

    2008-01-01

    Redox properties of cationic dye phenosafranine (3,7-diamino-5-phenylphenazenium chloride) (PS + ) were studied at zeolite-modified electrodes using Zeolite-Y and NaZSM-5. The peak current and peak potential of phenosafranine-adsorbed zeolite were found to be influenced by the pH of the electrolyte solution. Observation of a second redox couple is suggested to be due to formation of new species at low concentration from the reduced phenosafranine at the zeolite-modified electrodes. Titanium dioxide nanoparticles encapsulated in the cavities of the zeolite or anchored on the external surface of the zeolite do not seem to affect the redox properties of adsorbed PS + . When the cyclic voltammograms are recorded immediately after the electrode is immersed into the solution, the redox potential of PS + is found to be sensitive to the nature of the zeolite surface. The peak potential shifts towards positive region under continuous cycles as the surface hydroxyl groups get protonated in acidic electrolyte solution thereby forcing the movement of dye molecules from the zeolite surface to the zeolite electrode solution interface. The electron transfer rate constants for the adsorbed dye at the electrode are calculated to be 2.5 ± 0.2 s -1 and 3.5 ± 0.2 s -1 for the zeolite-Y electrode and the ZSM-5 electrode, respectively by the Laviron equation

  5. Mediatorless bioelectrocatalysis of dioxygen reduction at indium-doped tin oxide (ITO) and ITO nanoparticulate film electrodes

    International Nuclear Information System (INIS)

    Rozniecka, Ewa; Jonsson-Niedziolka, Martin; Sobczak, Janusz W.; Opallo, Marcin

    2011-01-01

    Highlights: → We introduced ITO nanoparticulate films for enzyme immobilization. → The material promotes mediatorless bioelectrocatalysis towards dioxygen reduction. → The electrocatalytical current increase with the thickness of nanoparticulate film. → There is no difference in electrocatalytic current in the presence or absence of mediator. → The stability of the electrode can be improved by crosslinking of the enzyme with bovine serum albumin and glutaraldehyde. - Abstract: Bilirubin oxidase was immobilised on ITO electrodes: bare or covered by ITO nanoparticulate film. The latter material was obtained by immersion and withdrawal of the substrate into ITO nanoparticles suspension. Formation of a protein deposit was confirmed by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The electrode surface is covered by a protein film in the form of globular aggregates and it exhibits mediatorless electrocatalytic activity towards dioxygen reduction to water at pH 4.8. Modification of the electrode with ITO particles increases its catalytic activity about ten times up to 110 μA cm -2 seen for electrodes prepared by twelve immersion and withdrawal steps into ITO nanoparticle suspension. The catalytic activity is almost unaffected by addition of mediator to solution. The stability of the electrodes is increased by cross-linking of the enzyme with bovine serum albumin and glutaraldehyde. This electrode was applied as biocathode in a zinc-dioxygen battery operating in 0.1 mol dm -3 McIlvaine buffer (pH 4.8).

  6. Bridging Redox Species-Coated Graphene Oxide Sheets to Electrode for Extending Battery Life Using Nanocomposite Electrolyte.

    Science.gov (United States)

    Huang, Yi Fu; Ruan, Wen Hong; Lin, Dong Ling; Zhang, Ming Qiu

    2017-01-11

    Substituting conventional electrolyte for redox electrolyte has provided a new intriguing method for extending battery life. The efficiency of utilizing the contained redox species (RS) in the redox electrolyte can benefit from increasing the specific surface area of battery electrodes from the electrode side of the electrode-electrolyte interface, but is not limited to that. Herein, a new strategy using nanocomposite electrolyte is proposed to enlarge the interface with the aid of nanoinclusions from the electrolyte side. To do this, graphene oxide (GO) sheets are first dispersed in the electrolyte solution of tungstosilicic salt/lithium sulfate/poly(vinyl alcohol) (SiWLi/Li 2 SO 4 /PVA), and then the sheets are bridged to electrode, after casting and evaporating the solution on the electrode surface. By applying in situ conductive atomic force microscopy and Raman spectra, it is confirmed that the GO sheets doped with RS of SiWLi/Li 2 SO 4 can be bridged and electrically reduced as an extended electrode-electrolyte interface. As a result, the RS-coated GO sheets bridged to LiTi 2 (PO 4 ) 3 //LiMn 2 O 4 battery electrodes are found to deliver extra energy capacity (∼30 mAh/g) with excellent electrochemical cycling stability, which successfully extends the battery life by over 50%.

  7. Mediatorless bioelectrocatalysis of dioxygen reduction at indium-doped tin oxide (ITO) and ITO nanoparticulate film electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Rozniecka, Ewa; Jonsson-Niedziolka, Martin; Sobczak, Janusz W. [Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warszawa (Poland); Opallo, Marcin, E-mail: mopallo@ichf.edu.pl [Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warszawa (Poland)

    2011-10-01

    Highlights: > We introduced ITO nanoparticulate films for enzyme immobilization. > The material promotes mediatorless bioelectrocatalysis towards dioxygen reduction. > The electrocatalytical current increase with the thickness of nanoparticulate film. > There is no difference in electrocatalytic current in the presence or absence of mediator. > The stability of the electrode can be improved by crosslinking of the enzyme with bovine serum albumin and glutaraldehyde. - Abstract: Bilirubin oxidase was immobilised on ITO electrodes: bare or covered by ITO nanoparticulate film. The latter material was obtained by immersion and withdrawal of the substrate into ITO nanoparticles suspension. Formation of a protein deposit was confirmed by scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy. The electrode surface is covered by a protein film in the form of globular aggregates and it exhibits mediatorless electrocatalytic activity towards dioxygen reduction to water at pH 4.8. Modification of the electrode with ITO particles increases its catalytic activity about ten times up to 110 {mu}A cm{sup -2} seen for electrodes prepared by twelve immersion and withdrawal steps into ITO nanoparticle suspension. The catalytic activity is almost unaffected by addition of mediator to solution. The stability of the electrodes is increased by cross-linking of the enzyme with bovine serum albumin and glutaraldehyde. This electrode was applied as biocathode in a zinc-dioxygen battery operating in 0.1 mol dm{sup -3} McIlvaine buffer (pH 4.8).

  8. Fabrication and Optimization of a Nanoporous Platinum Electrode and a Non-enzymatic Glucose Micro-sensor on Silicon

    Directory of Open Access Journals (Sweden)

    Younghun Kim

    2008-10-01

    Full Text Available In this paper, optimal conditions for fabrication of nanoporous platinum (Pt were investigated in order to use it as a sensitive sensing electrode for silicon CMOS integrable non-enzymatic glucose micro-sensor applications. Applied charges, voltages, and temperatures were varied during the electroplating of Pt into the formed nonionic surfactant C16EO8 nano-scaled molds in order to fabricate nanoporous Pt electrodes with large surface roughness factor (RF, uniformity, and reproducibility. The fabricated nanoporous Pt electrodes were characterized using atomic force microscopy (AFM and electrochemical cyclic voltammograms. Optimal electroplating conditions were determined to be an applied charge of 35 mC/mm2, a voltage of -0.12 V, and a temperature of 25 °C, respectively. The optimized nanoporous Pt electrode had an electrochemical RF of 375 and excellent reproducibility. The optimized nanoporous Pt electrode was applied to fabricate non-enzymatic glucose micro-sensor with three electrode systems. The fabricated sensor had a size of 3 mm x 3 mm, air gap of 10 µm, working electrode (WE area of 4.4 mm2, and sensitivity of 37.5 µA•L/mmol•cm2. In addition, it showed large detection range from 0.05 to 30 mmolL-1 and stable recovery responsive to the step changes in glucose concentration.

  9. Fabrication of Micro-Needle Electrodes for Bio-Signal Recording by a Magnetization-Induced Self-Assembly Method

    Directory of Open Access Journals (Sweden)

    Keyun Chen

    2016-09-01

    Full Text Available Micro-needle electrodes (MEs have attracted more and more attention for monitoring physiological electrical signals, including electrode-skin interface impedance (EII, electromyography (EMG and electrocardiography (ECG recording. A magnetization-induced self-assembling method (MSM was developed to fabricate a microneedle array (MA. A MA coated with Ti/Au film was assembled as a ME. The fracture and insertion properties of ME were tested by experiments. The bio-signal recording performance of the ME was measured and compared with a typical commercial wet electrode (Ag/AgCl electrode. The results show that the MA self-assembled from the magnetic droplet array under the sum of gravitational surface tension and magnetic potential energies. The ME had good toughness and could easily pierce rabbit skin without being broken or buckling. When the compression force applied on the ME was larger than 2 N, ME could stably record EII, which was a lower value than that measured by Ag/AgCl electrodes. EMG signals collected by ME varied along with the contraction of biceps brachii muscle. ME could record static ECG signals with a larger amplitude and dynamic ECG signals with more distinguishable features in comparison with a Ag/AgCl electrode, therefore, ME is an alternative electrode for bio-signal monitoring in some specific situations.

  10. Fabrication of a Micro-Needle Array Electrode by Thermal Drawing for Bio-Signals Monitoring.

    Science.gov (United States)

    Ren, Lei; Jiang, Qing; Chen, Keyun; Chen, Zhipeng; Pan, Chengfeng; Jiang, Lelun

    2016-06-17

    A novel micro-needle array electrode (MAE) fabricated by thermal drawing and coated with Ti/Au film was proposed for bio-signals monitoring. A simple and effective setup was employed to form glassy-state poly (lactic-co-glycolic acid) (PLGA) into a micro-needle array (MA) by the thermal drawing method. The MA was composed of 6 × 6 micro-needles with an average height of about 500 μm. Electrode-skin interface impedance (EII) was recorded as the insertion force was applied on the MAE. The insertion process of the MAE was also simulated by the finite element method. Results showed that MAE could insert into skin with a relatively low compression force and maintain stable contact impedance between the MAE and skin. Bio-signals, including electromyography (EMG), electrocardiography (ECG), and electroencephalograph (EEG) were also collected. Test results showed that the MAE could record EMG, ECG, and EEG signals with good fidelity in shape and amplitude in comparison with the commercial Ag/AgCl electrodes, which proves that MAE is an alternative electrode for bio-signals monitoring.

  11. Fabrication of a Micro-Needle Array Electrode by Thermal Drawing for Bio-Signals Monitoring

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2016-06-01

    Full Text Available A novel micro-needle array electrode (MAE fabricated by thermal drawing and coated with Ti/Au film was proposed for bio-signals monitoring. A simple and effective setup was employed to form glassy-state poly (lactic-co-glycolic acid (PLGA into a micro-needle array (MA by the thermal drawing method. The MA was composed of 6 × 6 micro-needles with an average height of about 500 μm. Electrode-skin interface impedance (EII was recorded as the insertion force was applied on the MAE. The insertion process of the MAE was also simulated by the finite element method. Results showed that MAE could insert into skin with a relatively low compression force and maintain stable contact impedance between the MAE and skin. Bio-signals, including electromyography (EMG, electrocardiography (ECG, and electroencephalograph (EEG were also collected. Test results showed that the MAE could record EMG, ECG, and EEG signals with good fidelity in shape and amplitude in comparison with the commercial Ag/AgCl electrodes, which proves that MAE is an alternative electrode for bio-signals monitoring.

  12. A study on fixing force generation mechanism of ER gel

    International Nuclear Information System (INIS)

    Tanaka, H; Kakinuma, Y; Aoyama, T; Anzai, H

    2009-01-01

    Electro-rheological Gel (ERG) is a new functional elastomer which changes its surface frictional and adhesive property according to the intensity of applied electrical field. This unique property is called ERG effect. The upper sliding electrode placed on the surface of ERG is fixed by the adhesive effect of ERG under electrical field. Variable fixing forces due to adhesion are generated by this effect. However, relationship between physical factors and generated fixing force has not yet been clarified. In this study, physical mechanism of fixing phenomenon is elucidated experimentally from the view point of frictional force and adhesive force. From the results, empirical equation of generated fixing force is originally derived to establish the theory of ERG effect.

  13. A study on fixing force generation mechanism of ER gel

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H; Kakinuma, Y; Aoyama, T [School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Anzai, H [Fujikura kasei Co., Ltd., 2-6-15 Shibakouen, Minato-ku, Tokyo (Japan)], E-mail: h-tanaka@ina.sd.keio.ac.jp

    2009-02-01

    Electro-rheological Gel (ERG) is a new functional elastomer which changes its surface frictional and adhesive property according to the intensity of applied electrical field. This unique property is called ERG effect. The upper sliding electrode placed on the surface of ERG is fixed by the adhesive effect of ERG under electrical field. Variable fixing forces due to adhesion are generated by this effect. However, relationship between physical factors and generated fixing force has not yet been clarified. In this study, physical mechanism of fixing phenomenon is elucidated experimentally from the view point of frictional force and adhesive force. From the results, empirical equation of generated fixing force is originally derived to establish the theory of ERG effect.

  14. Organophosphonate biofunctionalization of diamond electrodes.

    Science.gov (United States)

    Caterino, R; Csiki, R; Wiesinger, M; Sachsenhauser, M; Stutzmann, M; Garrido, J A; Cattani-Scholz, A; Speranza, Giorgio; Janssens, S D; Haenen, K

    2014-08-27

    The modification of the diamond surface with organic molecules is a crucial aspect to be considered for any bioapplication of this material. There is great interest in broadening the range of linker molecules that can be covalently bound to the diamond surface. In the case of protein immobilization, the hydropathicity of the surface has a major influence on the protein conformation and, thus, on the functionality of proteins immobilized at surfaces. For electrochemical applications, particular attention has to be devoted to avoid that the charge transfer between the electrode and the redox center embedded in the protein is hindered by a thick insulating linker layer. This paper reports on the grafting of 6-phosphonohexanoic acid on OH-terminated diamond surfaces, serving as linkers to tether electroactive proteins onto diamond surfaces. X-ray photoelectron spectroscopy (XPS) confirms the formation of a stable layer on the surface. The charge transfer between electroactive molecules and the substrate is studied by electrochemical characterization of the redox activity of aminomethylferrocene and cytochrome c covalently bound to the substrate through this linker. Our work demonstrates that OH-terminated diamond functionalized with 6-phosphonohexanoic acid is a suitable platform to interface redox-proteins, which are fundamental building blocks for many bioelectronics applications.

  15. A reference electrode based on polyvinyl butyral (PVB) polymer for decentralized chemical measurements

    Energy Technology Data Exchange (ETDEWEB)

    Guinovart, Tomàs [Departament de Química Orgànica i Química Analítica, Universitat Rovira i Virgili, Carrer Marcellí Domingo s/n 43007 Tarragona (Spain); Crespo, Gastón A. [Department of Inorganic and Analytical Chemistry, University of Geneva, Quai Ernest-Ansermet 30, CH-1211 Geneva (Switzerland); Rius, F. Xavier [Departament de Química Orgànica i Química Analítica, Universitat Rovira i Virgili, Carrer Marcellí Domingo s/n 43007 Tarragona (Spain); Andrade, Francisco J., E-mail: franciscojavier.andrade@urv.cat [Departament de Química Orgànica i Química Analítica, Universitat Rovira i Virgili, Carrer Marcellí Domingo s/n 43007 Tarragona (Spain)

    2014-04-01

    Highlights: • A disposable solid-contact reference electrode for potentiometry is presented. • The device shows unsensitivity to most ions, redox potential and light. • Low-cost and good stability, ideal to build disposable potentiometric sensors. • Nanopores formed in the membrane control the flux of ions with the solution. Abstract: A new solid-state reference electrode using a polymeric membrane of polyvinyl butyral (PVB), Ag/AgCl and NaCl to be used in decentralized chemical measurements is presented. The electrode is made by drop-casting the membrane cocktail onto a glassy carbon (GC) substrate. A stable potential (less than 1 mV dec⁻¹ over a wide range of concentrations for the several chemical species tested is obtained. No significant influence to changes in redox potential, light and pH are observed. The response of this novel electrode shows good correlation when compared with a conventional double-junction reference electrode. Also good long-term stability (90 ± 33 μV/h) and a lifetime of approximately 4 months are obtained. Aspects related to the working mechanisms are discussed. Atomic Force Microscopy (AFM) studies reveal the presence of nanopores and channels on the surface, and electrochemical impedance spectroscopy (EIS) of optimized electrodes show low bulk resistances, usually in the kΩ range, suggesting that a nanoporous polymeric structure is formed in the interface with the solution. Future applications of this electrode as a disposable device for decentralized measurements are discussed. Examples of the utilization on wearable substrates (tattoos, fabrics, etc) are provided.

  16. Electrochemical, morphological and microstructural characterization of carbon film resistor electrodes for application in electrochemical sensors

    International Nuclear Information System (INIS)

    Gouveia-Caridade, Carla; Soares, David M.; Liess, Hans-Dieter; Brett, Christopher M.A.

    2008-01-01

    The electrochemical and microstructural properties of carbon film electrodes made from carbon film electrical resistors of 1.5, 15, 140 Ω and 2.0 kΩ nominal resistance have been investigated before and after electrochemical pre-treatment at +0.9 V vs SCE, in order to assess the potential use of these carbon film electrodes as electrochemical sensors and as substrates for sensors and biosensors. The results obtained are compared with those at electrodes made from previously investigated 2 Ω carbon film resistors. Cyclic voltammetry was performed in acetate buffer and phosphate buffer saline electrolytes and the kinetic parameters of the model redox system Fe(CN) 6 3-/4- obtained. The 1.5 Ω resistor electrodes show the best properties for sensor development with wide potential windows, similar electrochemical behaviour to those of 2 Ω and close-to-reversible kinetic parameters after electrochemical pre-treatment. The 15 and 140 Ω resistor electrodes show wide potential windows although with slower kinetics, whereas the 2.0 kΩ resistor electrodes show poor cyclic voltammetric profiles even after pre-treatment. Electrochemical impedance spectroscopy related these findings to the interfacial properties of the electrodes. Microstructural and morphological studies were carried out using contact mode Atomic Force Microscopy (AFM), Confocal Raman spectroscopy and X-ray diffraction. AFM showed more homogeneity of the films with lower nominal resistances, related to better electrochemical characteristics. X-ray diffraction and Confocal Raman spectroscopy indicate the existence of a graphitic structure in the carbon films

  17. A model for crack initiation in the Li-ion battery electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Panat, Rahul, E-mail: rahul.panat@wsu.edu

    2015-12-01

    The development of high energy density Lithium-ion batteries is of intense interest due to their application in the electric car and consumer electronics industry. The primary limiter in using high energy density battery electrodes is the cracking of the electrode material due to the severe strain caused by the charging–discharging cycles. In this paper, a linear perturbation model is used to describe the evolution of the electrode surface under stress. The driving force for the surface undulation formation is the reduction in the electrode strain energy. The kinetics of mass transport is described by the surface and volume diffusion. The model predicts that the Si electrode will develop surface undulations of the order of sub-1 μm length scale on the electrode surface, showing a reasonable agreement with experimental results reported in literature. Such surface undulations roughen the anode surface and can form notches that can act as crack initiation sites. It is also shown that this model is applicable when the temperature of the system is not constant and the system is not isolated. The limitations of the model are also discussed. - Highlights: • This work presents a theoretical formulation that predicts crack formation at an electrode surface under a lithiation cycle. • The research provides the critical parameters required to improve the life of the Li-ion batteries. • These research findings can be used to modify the surface structure to minimize crack formation. • The predictions from the model show a reasonable agreement with the experiments. • None of the theoretical literature so far has addressed the crack formation problem addressed in this paper.

  18. Electrode erosion properties of gas spark switches for fast linear transformer drivers

    Science.gov (United States)

    Li, Xiaoang; Pei, Zhehao; Zhang, Yuzhao; Liu, Xuandong; Li, Yongdong; Zhang, Qiaogen

    2017-12-01

    Fast linear transformer drivers (FLTDs) are a popular and potential route for high-power devices employing multiple "bricks" in series and parallel, but they put extremely stringent demands on gas switches. Electrode erosion of FLTD gas switches is a restrictive and unavoidable factor that degrades performance and limits stability. In this paper, we systematically investigated the electrode erosion characteristics of a three-electrode field distortion gas switch under the typical working conditions of FLTD switches, and the discharge current was 7-46 kA with 46-300 ns rise time. A high speed frame camera and a spectrograph were used to capture the expansion process and the spectral emission of the spark channel was used to estimate the current density and the spark temperature, and then the energy fluxes and the external forces on the electrode surface were calculated. A tens of kilo-ampere nanosecond pulse could generate a 1011 W/m2 energy flux injection and 1.3-3.5 MPa external pressure on the electrode surface, resulting in a millimeter-sized erosion crater with the maximum peak height Rz reaching 100 μm magnitude. According to the morphological images by a laser scanning confocal microscope, the erosion crater of a FLTD switch contained three kinds of local morphologies, namely a center boiling region, an overflow region and a sputtering region. In addition, the crater size, the surface roughness, and the mass loss were highly dependent on the current amplitude and the transferred charge. We also observed Morphology Type I and Type II, respectively, with different pulse parameters, which had an obvious influence on surface roughness and mass loss. Finally, the quantitative relationship between the electrode mass loss and the pulse parameter was clarified. The transferred charge and the current amplitude were proved to be the main factors determining the electrode mass loss of a FLTD switch, and a least squares fitting expression for mass loss was also obtained.

  19. A reference electrode based on polyvinyl butyral (PVB) polymer for decentralized chemical measurements

    International Nuclear Information System (INIS)

    Guinovart, Tomàs; Crespo, Gastón A.; Rius, F. Xavier; Andrade, Francisco J.

    2014-01-01

    Highlights: • A disposable solid-contact reference electrode for potentiometry is presented. • The device shows unsensitivity to most ions, redox potential and light. • Low-cost and good stability, ideal to build disposable potentiometric sensors. • Nanopores formed in the membrane control the flux of ions with the solution. - Abstract: A new solid-state reference electrode using a polymeric membrane of polyvinyl butyral (PVB), Ag/AgCl and NaCl to be used in decentralized chemical measurements is presented. The electrode is made by drop-casting the membrane cocktail onto a glassy carbon (GC) substrate. A stable potential (less than 1 mV dec −1 ) over a wide range of concentrations for the several chemical species tested is obtained. No significant influence to changes in redox potential, light and pH are observed. The response of this novel electrode shows good correlation when compared with a conventional double-junction reference electrode. Also good long-term stability (90 ± 33 μV/h) and a lifetime of approximately 4 months are obtained. Aspects related to the working mechanisms are discussed. Atomic Force Microscopy (AFM) studies reveal the presence of nanopores and channels on the surface, and electrochemical impedance spectroscopy (EIS) of optimized electrodes show low bulk resistances, usually in the kΩ range, suggesting that a nanoporous polymeric structure is formed in the interface with the solution. Future applications of this electrode as a disposable device for decentralized measurements are discussed. Examples of the utilization on wearable substrates (tattoos, fabrics, etc) are provided

  20. Cell Fragmentation and Permeabilization by a 1 ns Pulse Driven Triple-Point Electrode

    Directory of Open Access Journals (Sweden)

    Enbo Yang

    2018-01-01

    Full Text Available Ultrashort electric pulses (ns-ps are useful in gaining understanding as to how pulsed electric fields act upon biological cells, but the electric field intensity to induce biological responses is typically higher than longer pulses and therefore a high voltage ultrashort pulse generator is required. To deliver 1 ns pulses with sufficient electric field but at a relatively low voltage, we used a glass-encapsulated tungsten wire triple-point electrode (TPE at the interface among glass, tungsten wire, and water when it is immersed in water. A high electric field (2 MV/cm can be created when pulses are applied. However, such a high electric field was found to cause bubble emission and temperature rise in the water near the electrode. They can be attributed to Joule heating near the electrode. Adherent cells on a cover slip treated by the combination of these stimuli showed two major effects: (1 cells in a crater (<100 μm from electrode were fragmented and the debris was blown away. The principal mechanism for the damage is presumed to be shear forces due to bubble collapse; and (2 cells in the periphery of the crater were permeabilized, which was due to the combination of bubble movement and microstreaming as well as pulsed electric fields. These results show that ultrashort electric fields assisted by microbubbles can cause significant cell response and therefore a triple-point electrode is a useful ablation tool for applications that require submillimeter precision.

  1. Strategies for an enzyme immobilization on electrodes: Structural and electrochemical characterizations

    Science.gov (United States)

    Ganesh, V.; Muthurasu, A.

    2012-04-01

    In this paper, we propose various strategies for an enzyme immobilization on electrodes (both metal and semiconductor electrodes). In general, the proposed methodology involves two critical steps viz., (1) chemical modification of substrates using functional monolayers [Langmuir - Blodgett (LB) films and/or self-assembled monolayers (SAMs)] and (2) anchoring of a target enzyme using specific chemical and physical interactions by attacking the terminal functionality of the modified films. Basically there are three ways to immobilize an enzyme on chemically modified electrodes. First method consists of an electrostatic interaction between the enzyme and terminal functional groups present within the chemically modified films. Second and third methods involve the introduction of nanomaterials followed by an enzyme immobilization using both the physical and chemical adsorption processes. As a proof of principle, in this work we demonstrate the sensing and catalytic activity of horseradish peroxidase (HRP) anchored onto SAM modified indium tin oxide (ITO) electrodes towards hydrogen peroxide (H2O2). Structural characterization of such modified electrodes is performed using X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurements. The binding events and the enzymatic reactions are monitored using electrochemical techniques mainly cyclic voltammetry (CV).

  2. Bi-axially crumpled silver thin-film electrodes for dielectric elastomer actuators

    International Nuclear Information System (INIS)

    Low, Sze-Hsien; Lau, Gih-Keong

    2014-01-01

    Metal thin films, which have high conductivity, are much stiffer and may fracture at a much lower strain than dielectric elastomers. In order to fabricate compliant electrodes for use in dielectric elastomer actuators (DEAs), metal thin films have been formed into either zigzag patterns or corrugations, which favour bending and only allow uniaxial DEA deformations. However, biaxially compliant electrodes are desired in order to maximize generated forces of DEA. In this paper, we present crumpled metal thin-film electrodes that are biaxially compliant and have full area coverage over the dielectric elastomer. These crumpled metal thin-film electrodes are more stretchable than flat metal thin films; they remain conductive beyond 110% radial strain. Also, crumpling reduced the stiffening effect of metal thin films on the soft elastomer. As such, DEAs using crumpled metal thin-film electrodes managed to attain relatively high actuated area strains of up to 128% at 1.8 kV (102 Vμm −1 ). (paper)

  3. Electrochemical behavior of an anticancer drug 5-fluorouracil at methylene blue modified carbon paste electrode

    International Nuclear Information System (INIS)

    Bukkitgar, Shikandar D.; Shetti, Nagaraj P.

    2016-01-01

    A novel sensor for the determination of 5-fluorouracil was constructed by electrochemical deposition of methylene blue on surface of carbon paste electrode. The electrode surface morphology was studied using Atomic force microscopy and XRD. The electrochemical activity of modified electrode was characterized using cyclic voltammetry and differential pulse method. The developed sensor shows impressive enlargement in sensitivity of 5-fluorouracil determination. The peak currents obtained from differential pulse voltammetry was linear with concentration of 5-fluorouracil in the range 4 × 10 −5 –1 × 10 −7 M and detection limit and quantification limit were calculated to be 2.04 nM and 6.18 nM respectively. Further, the sensor was successfully applied in pharmaceutical and biological fluid sample analysis. - Highlights: • Electrochemical oxidation of 5-fluorouracil has been investigated for first time at methylene blue modified carbon paste electrode • The electrode process was irreversible and diffusion controlled • Probable electrochemical mechanism was proposed which involved two proton and two electron transfer reaction • The LOD and LOQ values were calculated to be 2.04 nM and 6.18 nM, respectively, with good selectivity and sensitivity. • Proposed method was applied to 5-Fluorouracil determination in pharmaceutical and spiked human urine samples

  4. An 11 μ w, two-electrode transimpedance biosignal amplifier with active current feedback stabilization.

    Science.gov (United States)

    Inan, O T; Kovacs, G T A

    2010-04-01

    A novel two-electrode biosignal amplifier circuit is demonstrated by using a composite transimpedance amplifier input stage with active current feedback. Micropower, low gain-bandwidth product operational amplifiers can be used, leading to the lowest reported overall power consumption in the literature for a design implemented with off-the-shelf commercial integrated circuits (11 μW). Active current feedback forces the common-mode input voltage to stay within the supply rails, reducing baseline drift and amplifier saturation problems that can be present in two-electrode systems. The bandwidth of the amplifier extends from 0.05-200 Hz and the midband voltage gain (assuming an electrode-to-skin resistance of 100 kΩ) is 48 dB. The measured output noise level is 1.2 mV pp, corresponding to a voltage signal-to-noise ratio approaching 50 dB for a typical electrocardiogram (ECG) level input of 1 mVpp. Recordings were taken from a subject by using the proposed two-electrode circuit and, simultaneously, a three-electrode standard ECG circuit. The residual of the normalized ensemble averages for both measurements was computed, and the power of this residual was 0.54% of the power of the standard ECG measurement output. While this paper primarily focuses on ECG applications, the circuit can also be used for amplifying other biosignals, such as the electroencephalogram.

  5. Modified glassy carbon electrodes based on carbon nanostructures for ultrasensitive electrochemical determination of furazolidone

    Energy Technology Data Exchange (ETDEWEB)

    Shahrokhian, Saeed, E-mail: shahrokhian@sharif.edu [Department of Chemistry, Sharif University of Technology, Tehran 11155-9516 (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Naderi, Leila [Department of Chemistry, Sharif University of Technology, Tehran 11155-9516 (Iran, Islamic Republic of); Ghalkhani, Masoumeh [Department of Chemistry, Faculty of Science, Shahid Rajaee Teacher Training University, Lavizan, Tehran (Iran, Islamic Republic of); Institute for advanced technology, Shahid Rajaee Teacher Training University, Lavizan, Tehran, 16788 (Iran, Islamic Republic of)

    2016-04-01

    The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the glassy carbon electrode modified with different carbon nanomaterials, including carbon nanotubes (CNTs), carbon nanoparticles (CNPs), nanodiamond-graphite (NDG), graphene oxide (GO), reduced graphene oxide (RGO) and RGO-CNT hybrids (various ratios) using linear sweep voltammetry (LSV). The results of voltammetric studies exhibited a considerable increase in the cathodic peak current of Fu at the RGO modified GCE, compared to other modified electrodes and also bare GCE. The surface morphology and nature of the RGO film was thoroughly characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The modified electrode showed two linear dynamic ranges of 0.001–2.0 μM and 2.0–10.0 μM with a detection limit of 0.3 nM for the voltammetric determination of Fu. This sensor was used successfully for Fu determination in pharmaceutical and clinical preparations. - Highlights: • The electrochemical behavior of Furazolidone (Fu) was investigated on the surface of the modified electrode with different carbon nanomaterials by Linear sweep voltammetry. • Two linear dynamic ranges and a low detection limit were obtained. • The modified electrode was applied for the detection of Fu in pharmaceutical and clinical preparations.

  6. A combined transcutaneous PO2-PCO2 electrode with electrochemical HCO3- stabilization.

    Science.gov (United States)

    Severinghaus, J W

    1981-10-01

    Combined transcutaneous PO2-PCO2 electrodes are described in which the interaction between the two electrodes due to OH- production at the O2 cathode has been eliminated. An anode of either anodized aluminum or platinum has been driven at a current equal to cathode current to force stoichiometric consumption of OH- at its rate of production. The AgCl reference electrode operates at zero current. O2 sensitivity was not significantly altered by electrolyte pH variation from 6.7 to 9.0 with variations by PCO2. These electrodes have been found stable both with and without spacers, and with electrolytes dissolved in 50-100% ethylene glycol. In 22 anesthetized patients, with electrode temperature of 43 degrees C (s refers to skin surface, a to arterial blood); PsO2 = 0.52PaO2 + 15 (range 54-300) (r = 0.66; Sy . x = 29.6; n = 46); and PsCO2 = 1.39PaCO2 + 2.1 (range 24-98) (r = 0.99; Sy . x = 2.28; n = 48).

  7. MIS gas sensors based on porous silicon with Pd and WO{sub 3}/Pd electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Solntsev, V.S. [Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028, Kiev (Ukraine); Gorbanyuk, T.I., E-mail: tatyanagor@mail.r [Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028, Kiev (Ukraine); Litovchenko, V.G.; Evtukh, A.A. [Institute of Semiconductor Physics, National Academy of Science of Ukraine, 03028, Kiev (Ukraine)

    2009-09-30

    Pd and WO{sub 3}/Pd gate metal-oxide-semiconductor (MIS) gas sensitive structures based on porous silicon layers are studied by the high frequency C(V) method. The chemical compositions of composite WO{sub 3}/Pd electrodes are characterized by secondary-ion mass spectrometry (SIMS). The atomic force microscopy (AFM) was used for morphologic studies of WO{sub 3}/Pd films. As shown in the experiments, WO{sub 3}/Pd structures are more sensitive and selective to the adsorption of hydrogen sulphide compared to Pd gate. The analyses of kinetic characteristics allow us to determine the response and characteristic times for these structures. The response time of MIS-structures with thin composite WO{sub 3}/Pd electrodes (the thickness of Pd is about 50 nm with WO{sub 3} clusters on its surface) is slower compared to the structures with Pd electrodes. Slower sensor responses of WO{sub 3}-based gas sensors may be associated with different mechanism of gas sensitivity of given structures. The enhanced sensitivity and selectivity to H{sub 2}S action of WO{sub 3}/Pd MIS-structures can also be explained by the chemical reaction that occurs at the catalytic active surface of gate electrodes. The possible mechanisms of enhanced sensitivity and selectivity to H{sub 2}S adsorption of MIS gas sensors with WO{sub 3}/Pd composite gate electrodes compared to pure Pd have been analyzed.

  8. Ion counting in supercapacitor electrodes using NMR spectroscopy.

    Science.gov (United States)

    Griffin, John M; Forse, Alexander C; Wang, Hao; Trease, Nicole M; Taberna, Pierre-Louis; Simon, Patrice; Grey, Clare P

    2014-01-01

    (19)F NMR spectroscopy has been used to study the local environments of anions in supercapacitor electrodes and to quantify changes in the populations of adsorbed species during charging. In the absence of an applied potential, anionic species adsorbed within carbon micropores (in-pore) are distinguished from those in large mesopores and spaces between particles (ex-pore) by a characteristic nucleus-independent chemical shift (NICS). Adsorption experiments and two-dimensional exchange experiments confirm that anions are in dynamic equilibrium between the in- and ex-pore environments with an exchange rate in the order of tens of Hz. (19)F in situ NMR spectra recorded at different charge states reveal changes in the intensity and NICS of the in-pore resonances, which are interpreted in term of changes in the population and local environments of the adsorbed anions that arise due to the charge-storage process. A comparison of the results obtained for a range of electrolytes reveals that several factors influence the charging mechanism. For a tetraethylammonium tetrafluoroborate electrolyte, positive polarisation of the electrode is found to proceed by anion adsorption at a low concentration, whereas increased ion exchange plays a more important role for a high concentration electrolyte. In contrast, negative polarization of the electrode proceeds by cation adsorption for both concentrations. For a tetrabutylammonium tetrafluoroborate electrolyte, anion expulsion is observed in the negative charging regime; this is attributed to the reduced mobility and/or access of the larger cations inside the pores, which forces the expulsion of anions in order to build up ionic charge. Significant anion expulsion is also observed in the negative charging regime for alkali metal bis(trifluoromethane)sulfonimide electrolytes, suggesting that more subtle factors also affect the charging mechanism.

  9. Forces in general relativity

    International Nuclear Information System (INIS)

    Ridgely, Charles T

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced by an observer in general coordinates. The general force is then applied to the local co-moving coordinate system of a uniformly accelerating observer, leading to an expression of the inertial force experienced by the observer. Next, applying the general force in Schwarzschild coordinates is shown to lead to familiar expressions of the gravitational force. As a more complex demonstration, the general force is applied to an observer in Boyer-Lindquist coordinates near a rotating, Kerr black hole. It is then shown that when the angular momentum of the black hole goes to zero, the force on the observer reduces to the force on an observer held stationary in Schwarzschild coordinates. As a final consideration, the force on an observer moving in rotating coordinates is derived. Expressing the force in terms of Christoffel symbols in rotating coordinates leads to familiar expressions of the centrifugal and Coriolis forces on the observer. It is envisioned that the techniques presented herein will be most useful to graduate level students, as well as those undergraduate students having experience with general relativity and tensor analysis.

  10. Micro-CAT with redundant electrodes (CATER)

    International Nuclear Information System (INIS)

    Berg, F.D. van den; Eijk, C.W.E. van; Hollander, R.W.; Sarro, P.M.

    2000-01-01

    High-rate X-ray or neutron counting introduces the problem of hit multiplicity when 2D position reconstruction is demanded. Implementation of a third readout electrode having a different angle than the anode or cathode allows to eliminate multiplicity problems. We present experimental results of a new type of gas-filled micro-patterned radiation detector, called 'Compteur a Trous a Electrodes Redondantes (CATER)', that disposes of such an extra readout channel in the form of a ring-shaped electrode that is positioned between the anode and the cathode. The ionic signal is shared between the ring-electrode and the cathode strip in a way that can be controlled by their potential difference. We observe a strong signal dependence on the drift field, which can be understood by the reduced transparency for the primary charge at high drift fields

  11. Improved technology for manufacture of carbon electrodes

    Indian Academy of Sciences (India)

    distribution, surface area, porosity, particle size distribution and type of pores. The .... the point from where the electrode sample has been drawn. ... In addition, qualitative information on the shape and the type of pores can be determined.

  12. Negative electrodes for Na-ion batteries.

    Science.gov (United States)

    Dahbi, Mouad; Yabuuchi, Naoaki; Kubota, Kei; Tokiwa, Kazuyasu; Komaba, Shinichi

    2014-08-07

    Research interest in Na-ion batteries has increased rapidly because of the environmental friendliness of sodium compared to lithium. Throughout this Perspective paper, we report and review recent scientific advances in the field of negative electrode materials used for Na-ion batteries. This paper sheds light on negative electrode materials for Na-ion batteries: carbonaceous materials, oxides/phosphates (as sodium insertion materials), sodium alloy/compounds and so on. These electrode materials have different reaction mechanisms for electrochemical sodiation/desodiation processes. Moreover, not only sodiation-active materials but also binders, current collectors, electrolytes and electrode/electrolyte interphase and its stabilization are essential for long cycle life Na-ion batteries. This paper also addresses the prospect of Na-ion batteries as low-cost and long-life batteries with relatively high-energy density as their potential competitive edge over the commercialized Li-ion batteries.

  13. Use of lanthanide catalysts in air electrodes

    International Nuclear Information System (INIS)

    Souza Parente, L.T. de

    1982-01-01

    A review on the lanthanide catalysts suitable for the reduction catalysis of oxygen in air electrodes is presented. The kinds of lanthanide indicated to be used as catalysts of oxygen reduction are shown. (A.R.H.) [pt

  14. Wearable Textile Electrodes for ECG Measurement

    Directory of Open Access Journals (Sweden)

    Lukas Vojtech

    2013-01-01

    Full Text Available The electrocardiogram (ECG is one of the most important parameters for monitoring of the physiological state of a person. Currently available systems for ECG monitoring are both stationary and wearable, but the comfort of the monitored person is not at a satisfactory level because these systems are not part of standard clothing. This article is therefore devoted to the development and measurement of wearable textile electrodes for ECG measurement device with high comfort for the user. The electrode material is made of electrically conductive textile. This creates a textile composite that guarantees high comfort for the user while ensuring good quality of ECG measurements. The composite is implemented by a carrier (a T-shirt with flame retardant and sensing electrodes embroidered with yarn based on a mixture of polyester coated with silver nanoparticles and cotton. The electrodes not only provide great comfort but are also antibacterial and antiallergic due to silver nanoparticles.

  15. The electrochemical impedance of metal hydride electrodes

    DEFF Research Database (Denmark)

    Valøen, Lars Ole; Lasia, Andrzej; Jensen, Jens Oluf

    2002-01-01

    The electrochemical impedance responses for different laboratory type metal hydride electrodes were successfully modeled and fitted to experimental data for AB5 type hydrogen storage alloys as well as one MgNi type electrode. The models fitted the experimental data remarkably well. Several AC......, explaining the experimental impedances in a wide frequency range for electrodes of hydride forming materials mixed with copper powder, were obtained. Both charge transfer and spherical diffusion of hydrogen in the particles are important sub processes that govern the total rate of the electrochemical...... hydrogen absorption/desorption reaction. To approximate the experimental data, equations describing the current distribution in porous electrodes were needed. Indications of one or more parallel reduction/oxidation processes competing with the electrochemical hydrogen absorption/desorption reaction were...

  16. Electrode Nanostructures in Lithium‐Based Batteries

    Science.gov (United States)

    Mahmood, Nasir

    2014-01-01

    Lithium‐based batteries possessing energy densities much higher than those of the conventional batteries belong to the most promising class of future energy devices. However, there are some fundamental issues related to their electrodes which are big roadblocks in their applications to electric vehicles (EVs). Nanochemistry has advantageous roles to overcome these problems by defining new nanostructures of electrode materials. This review article will highlight the challenges associated with these chemistries both to bring high performance and longevity upon considering the working principles of the various types of lithium‐based (Li‐ion, Li‐air and Li‐S) batteries. Further, the review discusses the advantages and challenges of nanomaterials in nanostructured electrodes of lithium‐based batteries, concerns with lithium metal anode and the recent advancement in electrode nanostructures. PMID:27980896

  17. Thin metal electrodes for semitransparent organic photovoltaics

    KAUST Repository

    Lee, Kyusung

    2013-08-01

    We demonstrate semitransparent organic photovoltaics (OPVs) based on thin metal electrodes and polymer photoactive layers consisting of poly(3-hexylthiophene) and [6,6]-phenyl C61 butyric acid methyl ester. The power conversion efficiency of a semitransparent OPV device comprising a 15-nm silver (Ag) rear electrode is 1.98% under AM 1.5-G illumination through the indium-tin-oxide side of the front anode at 100 mW/cm2 with 15.6% average transmittance of the entire cell in the visible wavelength range. As its thickness increases, a thin Ag electrode mainly influences the enhancement of the short circuit current density and fill factor. Its relatively low absorption intensity makes a Ag thin film a viable option for semitransparent electrodes compatible with organic layers. © 2013 ETRI.

  18. Electrode placement during electro-desalination of

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Andersson, Lovisa C. H.

    2017-01-01

    Carved stone sculptures and ornaments can be severely damaged by salt induced decay. Often the irregular surfaces are decomposed, and the artwork is lost. The present paper is an experimental investigation on the possibility for using electro-desalination for treatment of stone with irregular shape....... Electro-desalination experiments were made with different duration to follow the progress. Successful desalination of the whole stone piece was obtained, showing that also parts not being placed directly between the electrodes were desalinated. This is important in case of salt damaged carved stones......, where the most fragile parts thus can be desalinated without physically placing electrodes on them. The Cl removal rate was higher in the areas closest to the electrodes and slowest in the part, which was not placed directly between the electrodes. This is important to incorporate in the monitoring...

  19. Fluctuations at electrode-YSZ interfaces

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Hansen, Karin Vels; Skou, Eivind

    2005-01-01

    Current fluctuations at potentiostatically controlled point electrodes of Pt, La$_{0.85}$Sr$_{0.15}$MnO$_3$ and Ni on YSZ surfaces are determined at 1000$^\\circ$C. For the oxygen reduction process on Pt electrodes characteristic sawtooth shaped low frequency fluctuations are observed. At temperat......Current fluctuations at potentiostatically controlled point electrodes of Pt, La$_{0.85}$Sr$_{0.15}$MnO$_3$ and Ni on YSZ surfaces are determined at 1000$^\\circ$C. For the oxygen reduction process on Pt electrodes characteristic sawtooth shaped low frequency fluctuations are observed....../water atmosphere are presented for discussion. The origin of the observations is not known at present but it appears likely that they are related to the activation/deactivation mechanism of SOFCs....

  20. Nonlinear Dynamics of Carbon Nanotubes Under Large Electrostatic Force

    KAUST Repository

    Xu, Tiantian

    2015-06-01

    Because of the inherent nonlinearities involving the behavior of CNTs when excited by electrostatic forces, modeling and simulating their behavior is challenging. The complicated form of the electrostatic force describing the interaction of their cylindrical shape, forming upper electrodes, to lower electrodes poises serious computational challenges. This presents an obstacle against applying and using several nonlinear dynamics tools typically used to analyze the behavior of complicated nonlinear systems undergoing large motion, such as shooting, continuation, and integrity analysis techniques. This works presents an attempt to resolve this issue. We present an investigation of the nonlinear dynamics of carbon nanotubes when actuated by large electrostatic forces. We study expanding the complicated form of the electrostatic force into enough number of terms of the Taylor series. Then, we utilize this form along with an Euler-Bernoulli beam model to study for the first time the dynamic behavior of CNTs when excited by large electrostatic force. The geometric nonlinearity and the nonlinear electrostatic force are considered. An efficient reduced-order model (ROM) based on the Galerkin method is developed and utilized to simulate the static and dynamic responses of the CNTs. Several results are generated demonstrating softening and hardening behavior of the CNTs near their primary and secondary resonances. The effects of the DC and AC voltage loads on the behavior have been studied. The impacts of the initial slack level and CNT diameter are also demonstrated.

  1. NONLINEAR DYNAMICS OF CARBON NANOTUBES UNDER LARGE ELECTROSTATIC FORCE

    KAUST Repository

    Xu, Tiantian

    2015-06-01

    Because of the inherent nonlinearities involving the behavior of CNTs when excited by electrostatic forces, modeling and simulating their behavior is challenging. The complicated form of the electrostatic force describing the interaction of their cylindrical shape, forming upper electrodes, to lower electrodes poises serious computational challenges. This presents an obstacle against applying and using several nonlinear dynamics tools typically used to analyze the behavior of complicated nonlinear systems undergoing large motion, such as shooting, continuation, and integrity analysis techniques. This works presents an attempt to resolve this issue. We present an investigation of the nonlinear dynamics of carbon nanotubes when actuated by large electrostatic forces. We study expanding the complicated form of the electrostatic force into enough number of terms of the Taylor series. Then, we utilize this form along with an Euler-Bernoulli beam model to study for the first time the dynamic behavior of CNTs when excited by large electrostatic force. The geometric nonlinearity and the nonlinear electrostatic force are considered. An efficient reduced-order model (ROM) based on the Galerkin method is developed and utilized to simulate the static and dynamic responses of the CNTs. Several results are generated demonstrating softening and hardening behavior of the CNTs near their primary and secondary resonances. The effects of the DC and AC voltage loads on the behavior have been studied. The impacts of the initial slack level and CNT diameter are also demonstrated.

  2. Carbon nanocages as supercapacitor electrode materials.

    Science.gov (United States)

    Xie, Ke; Qin, Xingtai; Wang, Xizhang; Wang, Yangnian; Tao, Haisheng; Wu, Qiang; Yang, Lijun; Hu, Zheng

    2012-01-17

    Supercapacitor electrode materials: Carbon nanocages are conveniently produced by an in situ MgO template method and demonstrate high specific capacitance over a wide range of charging-discharging rates with high stability, superior to the most carbonaceous supercapacitor electrode materials to date. The large specific surface area, good mesoporosity, and regular structure are responsible for the excellent performance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Positive electrode for a lithium battery

    Science.gov (United States)

    Park, Sang-Ho; Amine, Khalil

    2015-04-07

    A method for producing a lithium alkali transition metal oxide for use as a positive electrode material for lithium secondary batteries by a precipitation method. The positive electrode material is a lithium alkali transition metal composite oxide and is prepared by mixing a solid state mixed with alkali and transition metal carbonate and a lithium source. The mixture is thermally treated to obtain a small amount of alkali metal residual in the lithium transition metal composite oxide cathode material.

  4. Conducting Polymer Electrodes for Gel Electrophoresis

    OpenAIRE

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D

    2014-01-01

    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 p-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 ...

  5. Hofmeister effects on the glucose oxidase hydrogel-modified electrode

    International Nuclear Information System (INIS)

    Suzuki, Aimi; Tsujimura, Seiya

    2016-01-01

    We describe the consistent effect of salts in the electrolyte solution on glucose oxidation current production in the redox hydrogel-modified electrode containing glucose oxidase as an electrocatalyst and Os complex mediator. The ions affect not only on the electron transfer between the enzyme and the Os complex, but also on the hydrogel structure. This study found that the degree of the effect can be characterized by Hofmeister series. The relative decrease in oxidization current is the lowest in the middle of the Hofmeister series, and increases monotonically on either side. An increase of ionic strength inhibits the electron transfer from the active site of glucose oxidase to Os complex. In addition to this, the kosmotropic anions, which are strongly hydrated, caused hydrogel deswelling (shrinking). The more chaotropic an ion is, the more it adsorbs to uncharged parts of polymer/enzyme with dispersion force, and the swelling of the hydrogel decreases the catalytic current. This study impacts the design of hydrogel electrode and selection of electrolyte ions for bioelectronic applications.

  6. Nanodomain Engineering in Ferroelectric Capacitors with Graphene Electrodes.

    Science.gov (United States)

    Lu, Haidong; Wang, Bo; Li, Tao; Lipatov, Alexey; Lee, Hyungwoo; Rajapitamahuni, Anil; Xu, Ruijuan; Hong, Xia; Farokhipoor, Saeedeh; Martin, Lane W; Eom, Chang-Beom; Chen, Long-Qing; Sinitskii, Alexander; Gruverman, Alexei

    2016-10-12

    Polarization switching in ferroelectric capacitors is typically realized by application of an electrical bias to the capacitor electrodes and occurs via a complex process of domain structure reorganization. As the domain evolution in real devices is governed by the distribution of the nucleation centers, obtaining a domain structure of a desired configuration by electrical pulsing is challenging, if not impossible. Recent discovery of polarization reversal via the flexoelectric effect has opened a possibility for deterministic control of polarization in ferroelectric capacitors. In this paper, we demonstrate mechanical writing of arbitrary-shaped nanoscale domains in thin-film ferroelectric capacitors with graphene electrodes facilitated by a strain gradient induced by a tip of an atomic force microscope (AFM). A phase-field modeling prediction of a strong effect of graphene thickness on the threshold load required to initiate mechanical switching has been confirmed experimentally. Deliberate voltage-free domain writing represents a viable approach for development of functional devices based on domain topology and electronic properties of the domains and domain walls.

  7. Malaysia and forced migration

    Directory of Open Access Journals (Sweden)

    Arzura Idris

    2012-06-01

    Full Text Available This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysia due to “south-south forced migration movements.” These responses are, however, inadequate in terms of commitment to the international refugee regime. While Malaysia did respond to economic and migration challenges, the paper asserts that such efforts are futile if she ignores issues critical to forced migrants.

  8. Labor Force Participation Rate

    Data.gov (United States)

    City and County of Durham, North Carolina — This thematic map presents the labor force participation rate of working-age people in the United States in 2010. The 2010 Labor Force Participation Rate shows the...

  9. Three-nucleon forces

    International Nuclear Information System (INIS)

    Sauer, P.U.

    2014-01-01

    In this paper, the role of three-nucleon forces in ab initio calculations of nuclear systems is investigated. The difference between genuine and induced many-nucleon forces is emphasized. Induced forces arise in the process of solving the nuclear many-body problem as technical intermediaries toward calculationally converged results. Genuine forces make up the Hamiltonian. They represent the chosen underlying dynamics. The hierarchy of contributions arising from genuine two-, three- and many-nucleon forces is discussed. Signals for the need of the inclusion of genuine three-nucleon forces are studied in nuclear systems, technically best under control, especially in three-nucleon and four-nucleon systems. Genuine three-nucleon forces are important for details in the description of some observables. Their contributions to observables are small on the scale set by two-nucleon forces. (author)

  10. RSOI: Force Deployment Bottleneck

    National Research Council Canada - National Science Library

    D'Amato, Mark

    1998-01-01

    .... This runs counter to the popular belief that strategic lift is the limiting constraint. The study begins by highlighting the genesis of the military's current force projection strategy and the resulting importance of rapid force deployments...

  11. Manufacturing process and electrode properties of palladium-electroded ionic polymer–metal composite

    International Nuclear Information System (INIS)

    Chang, Longfei; Chen, Hualing; Zhu, Zicai; Li, Bo

    2012-01-01

    This paper primarily focuses on the manufacturing process of palladium-electroded ionic polymer–metal composite (IPMC). First, according to the special properties of Pd, many experiments were done to determine several specific procedures, including the addition of a reducing agent and the time consumed. Subsequently, the effects of the core manufacturing steps on the electrode morphology were revealed by scanning electron microscopy studies of 22 IPMC samples treated with different combinations of manufacturing steps. Finally, the effects of electrode characteristics on the electromechanical properties, including the sheet resistivity, the elastic modulus and the electro-active performance, of IPMCs were evaluated experimentally and analyzed according to the electrode morphology. (paper)

  12. Cu mesh for flexible transparent conductive electrodes.

    Science.gov (United States)

    Kim, Won-Kyung; Lee, Seunghun; Hee Lee, Duck; Hee Park, In; Seong Bae, Jong; Woo Lee, Tae; Kim, Ji-Young; Hun Park, Ji; Chan Cho, Yong; Ryong Cho, Chae; Jeong, Se-Young

    2015-06-03

    Copper electrodes with a micromesh/nanomesh structure were fabricated on a polyimide substrate using UV lithography and wet etching to produce flexible transparent conducting electrodes (TCEs). Well-defined mesh electrodes were realized through the use of high-quality Cu thin films. The films were fabricated using radio-frequency (RF) sputtering with a single-crystal Cu target--a simple but innovative approach that overcame the low oxidation resistance of ordinary Cu. Hybrid Cu mesh electrodes were fabricated by adding a capping layer of either ZnO or Al-doped ZnO. The sheet resistance and the transmittance of the electrode with an Al-doped ZnO capping layer were 6.197 ohm/sq and 90.657%, respectively, and the figure of merit was 60.502 × 10(-3)/ohm, which remained relatively unchanged after thermal annealing at 200 °C and 1,000 cycles of bending. This fabrication technique enables the mass production of large-area flexible TCEs, and the stability and high performance of Cu mesh hybrid electrodes in harsh environments suggests they have strong potential for application in smart displays and solar cells.

  13. Nanofabrication strategies for advanced electrode materials

    Directory of Open Access Journals (Sweden)

    Chen Kunfeng

    2017-09-01

    Full Text Available The development of advanced electrode materials for high-performance energy storage devices becomes more and more important for growing demand of portable electronics and electrical vehicles. To speed up this process, rapid screening of exceptional materials among various morphologies, structures and sizes of materials is urgently needed. Benefitting from the advance of nanotechnology, tremendous efforts have been devoted to the development of various nanofabrication strategies for advanced electrode materials. This review focuses on the analysis of novel nanofabrication strategies and progress in the field of fast screening advanced electrode materials. The basic design principles for chemical reaction, crystallization, electrochemical reaction to control the composition and nanostructure of final electrodes are reviewed. Novel fast nanofabrication strategies, such as burning, electrochemical exfoliation, and their basic principles are also summarized. More importantly, colloid system served as one up-front design can skip over the materials synthesis, accelerating the screening rate of highperformance electrode. This work encourages us to create innovative design ideas for rapid screening high-active electrode materials for applications in energy-related fields and beyond.

  14. Characterization of sliders for efficient force generation of electrostatically controlled linear actuator

    International Nuclear Information System (INIS)

    Nguyen, T A; Konishi, S

    2014-01-01

    In this paper, the characterization of sliders for efficient force generation of an electrostatically controlled linear actuator (ECLIA) is investigated. The ECLIA consists of a piezoactuator (PZT), driving and holding electrodes, multiple sliders and a guide structure. The stepping motion of the sliders is driven by the PZT actuator via an electrostatic clutch mechanism. Thus, multiple sliders can achieve parallel, independent, precise motion, and a large stroke. Previous studies have indicated that the Si bulk slider and Si electrode created an air gap owing to the deformation of the Si electrode. Thus, the Si slider generated a low pushing force. In this study, we propose a fishbone structure mounted on a flexible slider to enhance the pushing force of the slider. The flexible slider, that can deform and fit into the Si electrode to reduce the air gap, results in highly efficient electrostatic-force generation. The fishbone structure improves the longitudinal stiffness of the flexible slider for high pushing-force generation. The results show that the pushing force created by the fishbone slider was three times greater than that of the conventional Si slider. The fishbone and flexible sliders exhibited a high performance for the ECLIA. (paper)

  15. Electrochemical characterisation of solid oxide cell electrodes for hydrogen production

    DEFF Research Database (Denmark)

    Bernuy-Lopez, Carlos; Knibbe, Ruth; He, Zeming

    2011-01-01

    Oxygen electrodes and steam electrodes are designed and tested to develop improved solid oxide electrolysis cells for H2 production with the cell support on the oxygen electrode. The electrode performance is evaluated by impedance spectroscopy testing of symmetric cells at open circuit voltage (OCV...

  16. Production of Manual Metal Arc Welding Electrodes with Local Raw ...

    African Journals Online (AJOL)

    Manual arc welding using flux coated electrodes is carried out by producing an electric arc between the base metal and a flux covered metal electrode with electric current that depends on the type of electrode, material, welding position and the desired strength. The composition of flux coated electrodes is complex and a ...

  17. Acoustic force spectroscopy

    NARCIS (Netherlands)

    Sitters, G.; Kamsma, D.; Thalhammer, G.; Ritsch-Marte, M.; Peterman, E.J.G.; Wuite, G.J.L.

    2015-01-01

    Force spectroscopy has become an indispensable tool to unravel the structural and mechanochemical properties of biomolecules. Here we extend the force spectroscopy toolbox with an acoustic manipulation device that can exert forces from subpiconewtons to hundreds of piconewtons on thousands of

  18. Crossflow force transducer

    International Nuclear Information System (INIS)

    Mulcahy, T.M.

    1982-05-01

    A force transducer for measuring lift and drag coefficients for a circular cylinder in turbulent water flow is presented. In addition to describing the actual design and construction of the strain-gauged force- ring based transducer, requirements for obtained valid fluid force test data are discussed, and pertinent flow test experience is related

  19. Forces in General Relativity

    Science.gov (United States)

    Ridgely, Charles T.

    2010-01-01

    Many textbooks dealing with general relativity do not demonstrate the derivation of forces in enough detail. The analyses presented herein demonstrate straightforward methods for computing forces by way of general relativity. Covariant divergence of the stress-energy-momentum tensor is used to derive a general expression of the force experienced…

  20. Air Force Senior Leaders

    Science.gov (United States)

    Force TV Radio Week in Photos About Us Air Force Senior Leaders SECAF CSAF CMSAF Biographies Adjunct Professors Senior Mentor Biographies Fact Sheets Commander's Call Topics CCT Archive CSAF Reading List 2017 Media Sites Site Registration Contact Us Search AF.mil: Home > About Us > Air Force Senior Leaders

  1. Monitoring drilling mud composition using flowing liquid junction electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Jasinski, R; Fletcher, P; Vercaemer, C

    1990-06-27

    The concentration of a chosen ionic component of a drilling mud is determined from the potential difference between an ion selective electrode, selective to the component and a reference electrode, the reference electrode being connected to the mud by a liquid junction through which reference electrolyte flows from the electrode to the mud. The system avoids errors due to undesirable interactions between the mud and the reference electrode materials. (author).

  2. Optimising carbon electrode materials for adsorptive stripping voltammetry

    OpenAIRE

    Chaisiwamongkhol, K; Batchelor-McAuley, C; Sokolov, S; Holter, J; Young, N; Compton, R

    2017-01-01

    Different types of carbon electrode materials for adsorptive stripping voltammetry are studied through the use of cyclic voltammetry. Capsaicin is utilised as a model compound for adsorptive stripping voltammetry using unmodified and modified basal plane pyrolytic graphite (BPPG) electrodes modified with multi-walled carbon nanotubes, carbon black or graphene nanoplatelets, screen printed carbon electrodes (SPE), carbon nanotube modified screen printed electrodes, and carbon paste electrodes....

  3. Quantum fictitious forces

    DEFF Research Database (Denmark)

    Bialynicki-Birula, I; Cirone, M.A.; Dahl, Jens Peder

    2002-01-01

    We present Heisenberg's equation of motion for the radial variable of a free non-relativistic particle in D dimensions. The resulting radial force consists of three contributions: (i) the quantum fictitious force which is either attractive or repulsive depending on the number of dimensions, (ii......) a singular quantum force located at the origin, and (iii) the centrifugal force associated with non-vanishing angular momentum. Moreover, we use Heisenberg's uncertainty relation to introduce a lower bound for the kinetic energy of an ensemble of neutral particles. This bound is quadratic in the number...... of atoms and can be traced back to the repulsive quantum fictitious potential. All three forces arise for a free particle: "Force without force"....

  4. A survey of reference electrodes for high temperature waters

    International Nuclear Information System (INIS)

    Molander, A.; Eriksson, Sture; Pein, K.

    2000-11-01

    In nuclear power plants, corrosion potential measurements are used to follow the conditions for different corrosion types in reactor systems, particularly IGSCC in BWRs. The goal of this work has been to give a survey of reference electrodes for high temperature water, both those that are used for nuclear environments and those that are judged to possible future development. The reference electrodes that are used today in nuclear power plants for corrosion potential measurements are of three types. Silver chloride electrodes, membrane electrodes and platinum electrodes (hydrogen electrodes). The principals for their function is described as well as the conversion of measured potentials to the SHE scale (Standard Hydrogen Electrode). Silver chloride electrodes consist of an inner reference system of silver chloride in equilibrium with a chloride solution. The silver chloride electrode is the most common reference electrode and can be used in several different systems. Platinum electrodes are usually more robust and are particularly suitable to use in BWR environment to follow the hydrogen dosage, but have limitations at low and no hydrogen dosage. Ceramic membrane electrodes can be with different types of internal reference system. They were originally developed for pH measurements in high temperature water. If pH is constant, the membrane electrode can be used as reference electrode. A survey of ceramic reference electrodes for high temperature water is given. A ceramic membrane of the type used works as an oxygen conductor, so the potential and pH in surrounding medium is in equilibrium with the internal reference system. A survey of the lately development of electrodes is presented in order to explain why the different types of electrodes are developed as well as to give a background to the possibilities and limitations with the different electrodes. Possibilities of future development of electrodes are also given. For measurements at low or no hydrogen dosage

  5. Force-free electromagnetic pulses in a laboratory plasma

    Science.gov (United States)

    Stenzel, R. L.; Urrutia, J. M.

    1990-01-01

    A short, intense current pulse is drawn from an electrode immersed in a magnetized afterglow plasma. The induced magnetic field B(r,t) assumes the shape of a helical double vortex which propagates along B(0) through the uniform plasma as a whistler mode. The observations support a prediction of force-free (J x B + neE = 0) electromagnetic fields and solitary waves. Energy and helicity are approximately conserved.

  6. 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.

  7. Built-in test of electrode degradation of multi-electrode array biosensors

    NARCIS (Netherlands)

    Liu, H.Y.; Dumas, N.; Richardson, A.; Heal, R.; Kerkhoff, Hans G.

    2006-01-01

    Micro-electrode array (MEA) is a widely used platform in biosensor systems, which provide a technology in communicating with micro chemical and biological world. This paper addresses hte topic of testing micro electrode degradation for MEAs, which is a common encountered damage during its

  8. Molecular imprinted polypyrrole modified glassy carbon electrode for the determination of tobramycin

    International Nuclear Information System (INIS)

    Gupta, Vinod Kumar; Yola, Mehmet Lütfi; Özaltın, Nuran; Atar, Necip; Üstündağ, Zafer; Uzun, Lokman

    2013-01-01

    Graphical abstract: Atomic force microscopic images of (A) bare GCE and (B) TOB imprinted PPy/GCE surface. - Highlights: • Glassy carbon electrode based on molecularly imprinted polypyrrole was prepared. • The developed surfaces were characterized by AFM, FTIR, EIS and CV. • The developed nanosensor was applied to egg and milk samples. - Abstract: Over the past two decades, molecular imprinted polymers have attracted a broad interest from scientists in sensor development. In the preparation of molecular imprinted polymers the desired molecule (template) induces the creation of specific recognition sites in the polymer. In this study, the glassy carbon electrode (GCE) based on molecularly imprinted polypyrrole (PPy) was fabricated for the determination of tobramycin (TOB). The developed electrode was prepared by incorporation of a template molecule (TOB) during the electropolymerization of pyrrole on GCE in aqueous solution using cyclic voltammetry (CV) method. The performance of the imprinted and non-imprinted electrodes was evaluated by square wave voltammetry (SWV). The effect of pH, monomer and template concentrations, electropolymerization cycles on the performance of the imprinted and non-imprinted electrodes was investigated and optimized. The non-modified and TOB-imprinted surfaces were characterized by using atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS) and CV. The linearity range of TOB was 5.0 × 10 −10 –1.0 × 10 −8 M with the detection limit of 1.4 × 10 −10 M. The developed nanosensor was applied successfully for the determination of TOB in egg and milk

  9. Nanowire Electrodes for Advanced Lithium Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lei; Wei, Qiulong; Sun, Ruimin; Mai, Liqiang, E-mail: mlq518@whut.edu.cn [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, WUT-Harvard Joint Nano Key Laboratory, Wuhan University of Technology, Wuhan (China)

    2014-10-27

    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 need 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 that the conductivity decrease of the nanowire electrode and the structural disorder/destruction during electrochemical reaction limit the cycling performance of LIBs. Based on the in situ observations, some feasible optimization 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 batteries are also described.

  10. Electrode redox reactions with polarizable molecules

    Science.gov (United States)

    Matyushov, Dmitry V.

    2018-04-01

    A theory of redox reactions involving electron transfer between a metal electrode and a polarizable molecule in solution is formulated. Both the existence of molecular polarizability and its ability to change due to electron transfer distinguish this problem from classical theories of interfacial electrochemistry. When the polarizability is different between the oxidized and reduced states, the statistics of thermal fluctuations driving the reactant over the activation barrier becomes non-Gaussian. The problem of electron transfer is formulated as crossing of two non-parabolic free energy surfaces. An analytical solution for these free energy surfaces is provided and the activation barrier of electrode electron transfer is given in terms of two reorganization energies corresponding to the oxidized and reduced states of the molecule in solution. The new non-Gaussian theory is, therefore, based on two theory parameters in contrast to one-parameter Marcus formulation for electrode reactions. The theory, which is consistent with the Nernst equation, predicts asymmetry between the cathodic and anodic branches of the electrode current. They show different slopes at small electrode overpotentials and become curved at larger overpotentials. However, the curvature of the Tafel plot is reduced compared to the Marcus-Hush model and approaches the empirical Butler-Volmer form with different transfer coefficients for the anodic and cathodic currents.

  11. FINAL REPORT: Transformational electrode drying process

    Energy Technology Data Exchange (ETDEWEB)

    Claus Daniel, C.; Wixom, M.(A123 Systems, Inc.)

    2013-12-19

    This report includes major findings and outlook from the transformational electrode drying project performance period from January 6, 2012 to August 1, 2012. Electrode drying before cell assembly is an operational bottleneck in battery manufacturing due to long drying times and batch processing. Water taken up during shipment and other manufacturing steps needs to be removed before final battery assembly. Conventional vacuum ovens are limited in drying speed due to a temperature threshold needed to avoid damaging polymer components in the composite electrode. Roll to roll operation and alternative treatments can increase the water desorption and removal rate without overheating and damaging other components in the composite electrode, thus considerably reducing drying time and energy use. The objective of this project was the development of an electrode drying procedure, and the demonstration of processes with no decrease in battery performance. The benchmark for all drying data was an 80°C vacuum furnace treatment with a residence time of 18 – 22 hours. This report demonstrates an alternative roll to roll drying process with a 500-fold improvement in drying time down to 2 minutes and consumption of only 30% of the energy compared to vacuum furnace treatment.

  12. Bioinspired fractal electrodes for solar energy storages.

    Science.gov (United States)

    Thekkekara, Litty V; Gu, Min

    2017-03-31

    Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10 -3  Whcm -3 . In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10 -1  Whcm -3 - more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications.

  13. 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.

  14. Microfabricated Reference Electrodes and their Biosensing Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen

    2010-03-01

    Full Text Available Over the past two decades, there has been an increasing trend towards miniaturization of both biological and chemical sensors and their integration with miniaturized sample pre-processing and analysis systems. These miniaturized lab-on-chip devices have several functional advantages including low cost, their ability to analyze smaller samples, faster analysis time, suitability for automation, and increased reliability and repeatability. Electrical based sensing methods that transduce biological or chemical signals into the electrical domain are a dominant part of the lab-on-chip devices. A vital part of any electrochemical sensing system is the reference electrode, which is a probe that is capable of measuring the potential on the solution side of an electrochemical interface. Research on miniaturization of this crucial component and analysis of the parameters that affect its performance, stability and lifetime, is sparse. In this paper, we present the basic electrochemistry and thermodynamics of these reference electrodes and illustrate the uses of reference electrodes in electrochemical and biological measurements. Different electrochemical systems that are used as reference electrodes will be presented, and an overview of some contemporary advances in electrode miniaturization and their performance will be provided.

  15. Bioinspired fractal electrodes for solar energy storages

    Science.gov (United States)

    Thekkekara, Litty V.; Gu, Min

    2017-03-01

    Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10-3 Whcm-3. In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10-1 Whcm-3- more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications.

  16. Nanowire Electrodes for Advanced Lithium Batteries

    International Nuclear Information System (INIS)

    Huang, Lei; Wei, Qiulong; Sun, Ruimin; Mai, Liqiang

    2014-01-01

    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 need 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 that the conductivity decrease of the nanowire electrode and the structural disorder/destruction during electrochemical reaction limit the cycling performance of LIBs. Based on the in situ observations, some feasible optimization 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 batteries are also described.

  17. Investigation of Heat Transfer and Magnetohydrodynamic Flow in Electroslag Remelting Furnace Using Vibrating Electrode

    Science.gov (United States)

    Wang, Fang; Wang, Qiang; Lou, Yanchun; Chen, Rui; Song, Zhaowei; Li, Baokuan

    2016-01-01

    A transient three-dimensional (3D) coupled mathematical model has been developed to understand the effect of a vibrating electrode on the electromagnetic, two-phase flow and temperature fields as well as the solidification in the electroslag remelting (ESR) process. With the magnetohydrodynamic model, the Joule heating and Lorentz force, which are the source terms in the energy and momentum equations, are recalculated at each iteration as a function of the phase distribution. The influence of the vibrating electrode on the formation of the metal droplet is demonstrated by the volume of fluid approach. Additionally, the solidification of the metal is modeled by an enthalpy-based technique, in which the mushy zone is treated as a porous medium with porosity equal to the liquid fraction. The present work is the first attempt to investigate the innovative technology of the ESR process with a vibrating electrode by a transient 3D comprehensive model. A reasonable agreement between the experiment and simulation is obtained. The results indicate that the whole process is presented as a periodic activity. When the metal droplets fall from the tip of the electrode, the horizontal component of velocity will generate electrode vibration. This will lead to the distribution variation of the flow field in the slag layer. The variation of temperature distribution occurs regularly and is periodically accompanied by the behavior of the falling metal droplets. With the decreasing vibrating frequency and amplitude, the relative velocity of the electrode and molten slag increase accordingly. The diameter of the molten droplets, the maximum temperature and the depth of the molten pool gradually become smaller, lower and shallower.

  18. High spatial resolution Kelvin probe force microscopy with coaxial probes

    International Nuclear Information System (INIS)

    Brown, Keith A; Westervelt, Robert M; Satzinger, Kevin J

    2012-01-01

    Kelvin probe force microscopy (KPFM) is a widely used technique to measure the local contact potential difference (CPD) between an AFM probe and the sample surface via the electrostatic force. The spatial resolution of KPFM is intrinsically limited by the long range of the electrostatic interaction, which includes contributions from the macroscopic cantilever and the conical tip. Here, we present coaxial AFM probes in which the cantilever and cone are shielded by a conducting shell, confining the tip–sample electrostatic interaction to a small region near the end of the tip. We have developed a technique to measure the true CPD despite the presence of the shell electrode. We find that the behavior of these probes agrees with an electrostatic model of the force, and we observe a factor of five improvement in spatial resolution relative to unshielded probes. Our discussion centers on KPFM, but the field confinement offered by these probes may improve any variant of electrostatic force microscopy. (paper)

  19. Effect of surface roughness and surface modification of indium tin oxide electrode on its potential response to tryptophan

    International Nuclear Information System (INIS)

    Khan, Md. Zaved Hossain; Nakanishi, Takuya; Kuroiwa, Shigeki; Hoshi, Yoichi; Osaka, Tetsuya

    2011-01-01

    Highlights: → We examine factors affecting potential response of ITO electrode to tryptophan. → Surface roughness of ITO electrode affects the stability of its rest potential. → Surface modification is effective for ITO electrode with a certain roughness. → Optimum values of work function exist for potential response of ITO to tryptophan. - Abstract: The effect of surface modification of indium tin oxide (ITO) electrode on its potential response to tryptophan was investigated for ITO substrates with different surface roughness. It was found that a small difference in surface roughness, between ∼1 and ∼2 nm of R a evaluated by atomic force microscopy, affects the rest potential of ITO electrode in the electrolyte. A slight difference in In:Sn ratio at the near surface of the ITO substrates, measured by angle-resolved X-ray photoelectron spectrometry and Auger electron spectroscopy is remarkable, and considered to relate with surface roughness. Interestingly, successive modification of the ITO surface with aminopropylsilane and disuccinimidyl suberate, of which essentiality to the potential response to indole compounds we previously reported, improved the stability of the rest potential and enabled the electrodes to respond to tryptophan in case of specimens with R a values ranging between ∼2 and ∼3 nm but not for those with R a of ∼1 nm. It was suggested that there are optimum values of effective work function of ITO for specific potential response to tryptophan, which can be obtained by the successive modification of ITO surface.

  20. Electrochemical solid-phase microextraction of anions and cations using polypyrrole coatings and an integrated three-electrode device.

    Science.gov (United States)

    Liljegren, Gustav; Pettersson, Jean; Markides, Karin E; Nyholm, Leif

    2002-05-01

    A method for the extraction, transfer and desorption of anions and cations under controlled potential conditions employing a new integrated three-electrode device is described. The device, containing working, reference and counter electrodes, was prepared from tubes that could be moved vertically with respect to each other. In this way, a small amount of solvent, held by capillary force, remained between the electrodes when the device was lifted out of a solution after an extraction. This design allowed the potential control to be maintained at all times. With the new integrated device, it was possible to perform potential controlled desorption into vials containing as little as 200 microl of solution. The required ion exchange capacity was obtained by electrodeposition of a polypyrrole coating on the surface of the glassy carbon working electrode. Solid-phase microextractions of several cations or anions were performed simultaneously under potentiostatic control by doping the polypyrrole coating with different anions such as perchlorate and p-toluenesulfonate. The efficiency of the extractions, which could be altered by varying the potential of the working electrode, could be increased by 150 to 200% compared to extractions using normal solid-phase microextraction conditions under open circuit conditions. A constant potential of +1.0 V and -0.5 V with respect to the silver pseudo reference electrode, was found to be well-suited for the extraction of samples containing ppm concentrations of anions (chloride, nitrite, bromide, nitrate, sulfate and phosphate) and cations (cadmium, cobalt and zinc), respectively.

  1. Effects of mesoscopic poly(3,4-ethylenedioxythiophene) films as counter electrodes for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Lee, Kun-Mu; Chiu, Wei-Hao; Wei, Hung-Yu; Hu, Chih-Wei; Suryanarayanan, Vembu; Hsieh, Weng-Feng; Ho, Kuo-Chuan

    2010-01-01

    Counter electrode coated with chemically polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) in a dye-sensitized solar cell (DSSC) was studied. The surface morphology and the nature of I - /I 3 - redox reaction based on PEDOT film were investigated using Atomic Force Microscopy and Cyclic Voltammetry, respectively. The performance of the DSSCs containing the PEDOT coated electrode was compared with sputtered-Pt electrode. We found that the root mean square roughness decreases and conductivity increases as the molar ratio of imidazole (Im)/EDOT in the PEDOT film increases. The DSSC containing the PEDOT coated on fluorine doped tin oxide glass with Im/EDOT molar ratio of 2.0, showed a conversion efficiency of 7.44% compared to that with sputtered-Pt electrode (7.77%). The high photocurrents were attributed to the large effective surface area of the electrode material resulting in good catalytic properties for I 3 - reduction. Therefore, the incorporation of a multi-walled carbon nanotube (MWCNT) in the PEDOT film, coated on various substrates was also investigated. The DSSC containing the PEDOT films with 0.6 wt.% of MWCNT on stainless steel as counter electrode had the best cell performance of 8.08% with short-circuit current density, open-circuit voltage and fill factor of 17.00 mA cm -2 , 720 mV and 0.66, respectively.

  2. Effects of mesoscopic poly(3,4-ethylenedioxythiophene) films as counter electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kun-Mu, E-mail: d93549007@ntu.edu.t [Photovoltaics Technology Center, Industrial Technology Research Institute, Chutung, Hsinchu 31040, Taiwan (China); Chiu, Wei-Hao [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Tahsueh Road, Hsinchu 30050, Taiwan (China); Wei, Hung-Yu; Hu, Chih-Wei [Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Suryanarayanan, Vembu [Electro Organic Division, Central Electrochemical Research Institute, Karaikudi 630 006 (India); Hsieh, Weng-Feng [Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Tahsueh Road, Hsinchu 30050, Taiwan (China); Ho, Kuo-Chuan [Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

    2010-01-01

    Counter electrode coated with chemically polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) in a dye-sensitized solar cell (DSSC) was studied. The surface morphology and the nature of I{sup -}/I{sub 3}{sup -} redox reaction based on PEDOT film were investigated using Atomic Force Microscopy and Cyclic Voltammetry, respectively. The performance of the DSSCs containing the PEDOT coated electrode was compared with sputtered-Pt electrode. We found that the root mean square roughness decreases and conductivity increases as the molar ratio of imidazole (Im)/EDOT in the PEDOT film increases. The DSSC containing the PEDOT coated on fluorine doped tin oxide glass with Im/EDOT molar ratio of 2.0, showed a conversion efficiency of 7.44% compared to that with sputtered-Pt electrode (7.77%). The high photocurrents were attributed to the large effective surface area of the electrode material resulting in good catalytic properties for I{sub 3}{sup -} reduction. Therefore, the incorporation of a multi-walled carbon nanotube (MWCNT) in the PEDOT film, coated on various substrates was also investigated. The DSSC containing the PEDOT films with 0.6 wt.% of MWCNT on stainless steel as counter electrode had the best cell performance of 8.08% with short-circuit current density, open-circuit voltage and fill factor of 17.00 mA cm{sup -2}, 720 mV and 0.66, respectively.

  3. StringForce

    DEFF Research Database (Denmark)

    Barendregt, Wolmet; Börjesson, Peter; Eriksson, Eva

    2017-01-01

    In this paper, we present the forced collaborative interaction game StringForce. StringForce is developed for a special education context to support training of collaboration skills, using readily available technologies and avoiding the creation of a "mobile bubble". In order to play String......Force two or four physically collocated tablets are required. These tablets are connected to form one large shared game area. The game can only be played by collaborating. StringForce extends previous work, both technologically and regarding social-emotional training. We believe String......Force to be an interesting demo for the IDC community, as it intertwines several relevant research fields, such as mobile interaction and collaborative gaming in the special education context....

  4. Quantum anticentrifugal force

    International Nuclear Information System (INIS)

    Cirone, M.A.; Schleich, W.P.; Straub, F.; Rzazewski, K.; Wheeler, J.A.

    2002-01-01

    In a two-dimensional world, a free quantum particle of vanishing angular momentum experiences an attractive force. This force originates from a modification of the classical centrifugal force due to the wave nature of the particle. For positive energies the quantum anticentrifugal force manifests itself in a bunching of the nodes of the energy wave functions towards the origin. For negative energies this force is sufficient to create a bound state in a two-dimensional δ-function potential. In a counterintuitive way, the attractive force pushes the particle away from the location of the δ-function potential. As a consequence, the particle is localized in a band-shaped domain around the origin

  5. Development of Wearable Sheet-Type Shear Force Sensor and Measurement System that is Insusceptible to Temperature and Pressure.

    Science.gov (United States)

    Toyama, Shigeru; Tanaka, Yasuhiro; Shirogane, Satoshi; Nakamura, Takashi; Umino, Tokio; Uehara, Ryo; Okamoto, Takuma; Igarashi, Hiroshi

    2017-07-31

    A sheet-type shear force sensor and a measurement system for the sensor were developed. The sensor has an original structure where a liquid electrolyte is filled in a space composed of two electrode-patterned polymer films and an elastic rubber ring. When a shear force is applied on the surface of the sensor, the two electrode-patterned films mutually move so that the distance between the internal electrodes of the sensor changes, resulting in current increase or decrease between the electrodes. Therefore, the shear force can be calculated by monitoring the current between the electrodes. Moreover, it is possible to measure two-dimensional shear force given that the sensor has multiple electrodes. The diameter and thickness of the sensor head were 10 mm and 0.7 mm, respectively. Additionally, we also developed a measurement system that drives the sensor, corrects the baseline of the raw sensor output, displays data, and stores data as a computer file. Though the raw sensor output was considerably affected by the surrounding temperature, the influence of temperature was drastically decreased by introducing a simple arithmetical calculation. Moreover, the influence of pressure simultaneously decreased after the same calculation process. A demonstrative measurement using the sensor revealed the practical usefulness for on-site monitoring.

  6. Relativistic Linear Restoring Force

    Science.gov (United States)

    Clark, D.; Franklin, J.; Mann, N.

    2012-01-01

    We consider two different forms for a relativistic version of a linear restoring force. The pair comes from taking Hooke's law to be the force appearing on the right-hand side of the relativistic expressions: d"p"/d"t" or d"p"/d["tau"]. Either formulation recovers Hooke's law in the non-relativistic limit. In addition to these two forces, we…

  7. Electrochemical behaviour of rhenium-graphite electrode

    International Nuclear Information System (INIS)

    Varypaev, V.N.; Krasikov, V.L.

    1980-01-01

    Electrochemical behaviour of combination electrode from graphite with electrodeposited thin coating of electrolytic rhenium is studied. Solution of 0.5 m NaCl+0.04 m AlCl 3 served as an electrolite. Polarization galvanostatic curves of hydrogen evolution upon electrodes with conditional rhenium thickness of 3.5 and 0.35 μm, 35 and 3.5 nm are obtained. Possibility of preparation of rhenium-graphite cathode with extremely low rhenium consume, electro-chemical properties of which are simu-lar to purely rhenium cathode is shown. Such electrode is characterized with stable in time low cathode potential of hydrogen evolution in chloride electrolyte and during cathode polarization it is not affected by corrosion

  8. Insulated electrocardiographic electrodes. [without paste electrolyte

    Science.gov (United States)

    David, R. M.; Portnoy, W. A. (Inventor)

    1975-01-01

    An integrated system is disclosed including an insulated electrode and an impedance transformer which can be assembled in a small plastic housing and used for the acquisition of electrocardiographic data. The electrode may be employed without a paste electrolyte and may be attached to the body for extended usage without producing skin reaction. The electrode comprises a thin layer of suitable nontoxic dielectric material preferably deposited by radio frequency sputtering onto a conductive substrate. The impedance transformer preferably comprises an operational amplifier having an FET input stage connected in the unity gain configuration which provides a very low lower cut-off frequency, a high input impedance with a very small input bias current, a low output impedance, and a high signal-to-noise ratio.

  9. Adsorption on smooth electrodes: A radiotracer study

    International Nuclear Information System (INIS)

    Rice-Jackson, L.M.

    1990-01-01

    Adsorption on solids is a complicated process and in most cases, occurs as the early stage of other more complicated processes, i.e. chemical reactions, electrooxidation, electroreduction. The research reported here combines the electroanalytical method, cyclic voltammetry, and the use of radio-labeled isotopes, soft beta emitters, to study adsorption processes at smooth electrodes. The in-situ radiotracer method is highly anion (molecule) specific and provides information on the structure and composition of the electric double layer. The emphasis of this research was on studying adsorption processes at smooth electrodes of copper, gold, and platinum. The application of the radiotracer method to these smooth surfaces have led to direct in-situ measurements from which surface coverage was determined; anions and molecules were identified; and weak interactions of adsorbates with the surface of the electrodes were readily monitored. 179 refs

  10. Capacitor with a composite carbon foam electrode

    Science.gov (United States)

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

    1999-01-01

    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 partides 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.

  11. DNA-FET using carbon nanotube electrodes

    International Nuclear Information System (INIS)

    Sasaki, T K; Ikegami, A; Aoki, N; Ochiai, Y

    2006-01-01

    We demonstrate DNA field effect transistor (DNA-FET) using multiwalled carbon nanotube (MWNT) as nano-structural source and drain electrodes. The MWNT electrodes have been fabricated by focused ion-beam bombardment (FIBB). A very short channel, approximately 50 nm, was easily formed between the severed MWNT. The current-voltage (I-V) characteristics of DNA molecules between the MWNT electrodes showed hopping transport property. We have also measured the gate-voltage dependence in the I-V characteristics and found that poly DNA molecules exhibits p-type conduction. The transport of DNA-FET can be explained by two hopping lengths which depend on the range of the source-drain bias voltages

  12. Hydrogen electrode reaction: A complete kinetic description

    International Nuclear Information System (INIS)

    Quaino, P.M.; Gennero de Chialvo, M.R.; Chialvo, A.C.

    2007-01-01

    The kinetic description of the hydrogen electrode reaction (HER) in the whole range of overpotentials (-0.2 < η (V) < 0.40) is presented. The Volmer-Heyrovsky-Tafel mechanism was solved considering simultaneously the following items: (i) the diffusional contribution of the molecular hydrogen from and towards the electrode surface, (ii) the forward and backward reaction rates of each elementary step and (iii) a Frumkin type adsorption for the reaction intermediate. In order to verify the descriptive capability of the kinetic expressions derived, an experimental study of the HER was carried out on a rotating platinum disc electrode in acid solution. From the correlation of these results the elementary kinetic parameters were evaluated and several aspects related to the kinetic mechanism were discussed. Finally, the use of these kinetic expressions to interpret results obtained on microelectrodes is also analysed

  13. Cleaved-edge-overgrowth nanogap electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Luber, Sebastian M; Bichler, Max; Abstreiter, Gerhard; Tornow, Marc, E-mail: m.tornow@tu-bs.de [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall, 85748 Garching (Germany)

    2011-02-11

    We present a method to fabricate multiple metal nanogap electrodes of tailored width and distance in parallel, on the cleaved plane of a GaAs/AlGaAs heterostructure. The three-dimensional patterned structures are obtained by a combination of molecular-beam-epitaxial regrowth on a crystal facet, using the cleaved-edge-overgrowth (CEO) method, and subsequent wet selective etching and metallization steps. SEM and AFM studies reveal smooth and co-planar electrodes of width and distance of the order of 10 nm. Preliminary electrical characterization indicates electrical gap insulation in the 100 M{Omega} range with k{Omega} lead resistance. We propose our methodology to realize multiple electrode geometries that would allow investigation of the electrical conductivity of complex nanoscale objects such as branched organic molecules.

  14. Cleaved-edge-overgrowth nanogap electrodes.

    Science.gov (United States)

    Luber, Sebastian M; Bichler, Max; Abstreiter, Gerhard; Tornow, Marc

    2011-02-11

    We present a method to fabricate multiple metal nanogap electrodes of tailored width and distance in parallel, on the cleaved plane of a GaAs/AlGaAs heterostructure. The three-dimensional patterned structures are obtained by a combination of molecular-beam-epitaxial regrowth on a crystal facet, using the cleaved-edge-overgrowth (CEO) method, and subsequent wet selective etching and metallization steps. SEM and AFM studies reveal smooth and co-planar electrodes of width and distance of the order of 10 nm. Preliminary electrical characterization indicates electrical gap insulation in the 100 MΩ range with kΩ lead resistance. We propose our methodology to realize multiple electrode geometries that would allow investigation of the electrical conductivity of complex nanoscale objects such as branched organic molecules.

  15. Ultrasonic cleaning of electrodes of wire chambers

    International Nuclear Information System (INIS)

    Krasnov, V.A.; Kurepin, A.B.; Razin, V.I.

    1980-01-01

    A technological process of cleaning electrodes and working volume surfaces of wire chambers from contaminations by the simultaneous mechanical action of the energy of ultrasonic oscillations and the chemical action of detergents is discussed. A device for cleaning wire electrodes of proportional chambers of 0.3x0.4 m is described. The device uses two ultrasonic generators with a total power of 0.5 kW. As a detergent use is made of a mixture of ethyl alcohol, gasoline and freon. In the process of cleaning production defects can be detected in the wire chambers which makes it possible to timely remove the defects. Measurements of the surface resistance of fiberglass laminate of printed drift chamber electrodes at a voltage of 2 kV showed that after completing the cleaning process the resistance increases 15-20%

  16. Static Response of Microbeams due to Capillary and Electrostatic Forces

    KAUST Repository

    Bataineh, Ahmad M.

    2016-03-07

    Micro-sensors or micro-switches usually operate under the effect of electrostatic force and could face some environmental effects like humidity, which may lead to condensation underneath the beams and create strong capillary forces. Those tiny structures are principally made of microbeams that can undergo instabilities under the effect of those created huge capillary forces. In fact, during the fabrication of microbeams, there is an important step to separate the beam from its substrate (wet etching). After this step, the microstructure is dried, which may causes the onset of some droplets of water trapped underneath the beam that could bring about a huge capillary force pulling it toward its substrate. If this force is bigger than the microbeam\\'s restoring force, it will become stuck to the substrate. This paper investigates the instability scenarios of both clamped-clamped (straight and curved) and cantilever (straight and curled) microbeams under the effect of capillary and/or electrostatic forces. The reduced order modeling (ROM) based on the Galerkin procedure is used to solve the nonlinear beam equations. The non-ideal boundaries are modeled by adding springs. The volume of the fluid between the beam and the substrate underneath it is varied and the relation between the volume of the water and the stability of the beam is shown. An analysis for the factors of which should be taken in to consideration in the fabrication processes to overcome the instability due to huge capillary forces is done. Also the size of the electrode for the electrostatic force is varied to show the effect on the micro-switch stability. A variation of the pull-in voltage with some specific beam parameters and with more than one case of electrode size is shown. It is found that capillary forces have a pronounced effect on the stability of microbeams. It is also found that the pull-in length decreases as the electrode size increases. It is also shown that the pull-in voltage decreases

  17. Hydrostatic force sensor

    International Nuclear Information System (INIS)

    Evans, M.S.; Stoughton, R.S.; Kazerooni, H.

    1994-08-01

    This paper presents a theoretical and experimental investigation of a new kind of force sensor which detects forces by measuring an induced pressure change in a material of large Poisson's ratio. In this investigation we develop mathematical expressions for the sensor's sensitivity and bandwidth, and show that its sensitivity can be much larger and its bandwidth is usually smaller than those of existing strain-gage-type sensors. This force sensor is well-suited for measuring large but slowly varying forces. It can be installed in a space smaller than that required by existing sensors

  18. Force induced DNA melting

    International Nuclear Information System (INIS)

    Santosh, Mogurampelly; Maiti, Prabal K

    2009-01-01

    When pulled along the axis, double-strand DNA undergoes a large conformational change and elongates by roughly twice its initial contour length at a pulling force of about 70 pN. The transition to this highly overstretched form of DNA is very cooperative. Applying a force perpendicular to the DNA axis (unzipping), double-strand DNA can also be separated into two single-stranded DNA, this being a fundamental process in DNA replication. We study the DNA overstretching and unzipping transition using fully atomistic molecular dynamics (MD) simulations and argue that the conformational changes of double-strand DNA associated with either of the above mentioned processes can be viewed as force induced DNA melting. As the force at one end of the DNA is increased the DNA starts melting abruptly/smoothly above a critical force depending on the pulling direction. The critical force f m , at which DNA melts completely decreases as the temperature of the system is increased. The melting force in the case of unzipping is smaller compared to the melting force when the DNA is pulled along the helical axis. In the case of melting through unzipping, the double-strand separation has jumps which correspond to the different energy minima arising due to sequence of different base pairs. The fraction of Watson-Crick base pair hydrogen bond breaking as a function of force does not show smooth and continuous behavior and consists of plateaus followed by sharp jumps.

  19. Intermolecular and surface forces

    CERN Document Server

    Israelachvili, Jacob N

    2011-01-01

    This reference describes the role of various intermolecular and interparticle forces in determining the properties of simple systems such as gases, liquids and solids, with a special focus on more complex colloidal, polymeric and biological systems. The book provides a thorough foundation in theories and concepts of intermolecular forces, allowing researchers and students to recognize which forces are important in any particular system, as well as how to control these forces. This third edition is expanded into three sections and contains five new chapters over the previous edition.· starts fr

  20. RSOI: Force Deployment Bottleneck

    National Research Council Canada - National Science Library

    D'Amato, Mark

    1998-01-01

    This study uses The Theory Of Constraints (TOC) management methodology and recent military missions to show that RSOI operations are generally the limiting constraint to force deployment operations...

  1. Air Force Academy Homepage

    Science.gov (United States)

    Communications Focal Point Contracting Squadron Force Support Squadron Mortuary Affairs Logistics Readiness Squadron Cadet Logistics Deployment and Distribution Material Management Operations PM Equipment Lab

  2. Drop detachment and motion on fuel cell electrode materials.

    Science.gov (United States)

    Gauthier, Eric; Hellstern, Thomas; Kevrekidis, Ioannis G; Benziger, Jay

    2012-02-01

    Liquid water is pushed through flow channels of fuel cells, where one surface is a porous carbon electrode made up of carbon fibers. Water drops grow on the fibrous carbon surface in the gas flow channel. The drops adhere to the superficial fiber surfaces but exhibit little penetration into the voids between the fibers. The fibrous surfaces are hydrophobic, but there is a substantial threshold force necessary to initiate water drop motion. Once the water drops begin to move, however, the adhesive force decreases and drops move with minimal friction, similar to motion on superhydrophobic materials. We report here studies of water wetting and water drop motion on typical porous carbon materials (carbon paper and carbon cloth) employed in fuel cells. The static coefficient of friction on these textured surfaces is comparable to that for smooth Teflon. But the dynamic coefficient of friction is several orders of magnitude smaller on the textured surfaces than on smooth Teflon. Carbon cloth displays a much smaller static contact angle hysteresis than carbon paper due to its two-scale roughness. The dynamic contact angle hysteresis for carbon paper is greatly reduced compared to the static contact angle hysteresis. Enhanced dynamic hydrophobicity is suggested to result from the extent to which a dynamic contact line can track topological heterogeneities of the liquid/solid interface.

  3. Simulation of a force on force exercise

    International Nuclear Information System (INIS)

    Terhune, R.; Van Slyke, D.; Sheppard, T.; Brandrup, M.

    1988-01-01

    The Security Exercise Evaluation System (SEES) is under development for use in planning Force on Force exercises and as an aid in post-exercise evaluation. This study is part of the development cycle where the simulation results are compared to field data to provide guidance for further development of the model. SEES is an event-driven stochastic computer program simulating individual movement and combat within an urban terrain environment. The simulator models the physics of movement, line of sight, and weapon effects. It relies on the controllers to provide all knowledge of security tactics, which are entered by the controllers during the simulation using interactive color graphic workstations. They are able to develop, modify and implement plans promptly as the simulator maintains real time. This paper reports on how SEES will be used to develop an intrusion plan, test the security response tactics and develop observer logistics. A Force on Force field exercise will then be executed to follow the plan with observations recorded. An analysis is made by first comparing the plan and events of the simulation with the field exercise, modifying the simulation plan to match the actual field exercise, and then running the simulation to develop a distribution of possible outcomes

  4. Equilibrium capillary forces with atomic force microscopy

    NARCIS (Netherlands)

    Sprakel, J.H.B.; Besseling, N.A.M.; Leermakers, F.A.M.; Cohen Stuart, M.A.

    2007-01-01

    We present measurements of equilibrium forces resulting from capillary condensation. The results give access to the ultralow interfacial tensions between the capillary bridge and the coexisting bulk phase. We demonstrate this with solutions of associative polymers and an aqueous mixture of gelatin

  5. Finite Element Analysis of the Vertical Levitation Force in an Electrostatic MEMS Comb Drive Actuator

    International Nuclear Information System (INIS)

    Wooldridge, J; Blackburn, J; Muniz-Piniella, A; Stewart, M; Shean, T A V; Weaver, P M; Cain, M G

    2013-01-01

    A vertical levitation electrostatic comb drive actuator was manufactured for the purpose of measuring piezoelectric coefficients in small-scale materials and devices. Previous modelling work on comb drive levitation has focussed on control of the levitation in standard poly-silicon devices in order to minimize effects on lateral modes of operation required for the accelerometer and gyroscope applications. The actuator developed in this study was manufactured using a 20 μm electroplated Ni process with a 25 μm trench created beneath the released structure through chemical wet etching. A finite element analysis using ZINC was used to model electrostatic potential around a cross section of one static and one movable electrode, from which the net levitation force per unit electrode was calculated. The model was first verified using the electrode geometry from previously studied systems, and then used to study the variation of force as a function of decreasing substrate-electrode distance. With the top electrode surfaces collinear the calculated force density is 0.00651 ε 0 V 2 M μm −1 , equivalent to a total force for the device of 36.4 μN at an applied voltage of V M =100 V, just 16% larger than the observed value. The measured increase in force with distance was smaller than predicted with the FEA, due to the geometry of the device in which the electrodes at the anchored ends of the supporting spring structure displace by a smaller amount than those at the centre

  6. System of fabricating a flexible electrode array

    Energy Technology Data Exchange (ETDEWEB)

    Krulevitch, Peter [Pleasanton, CA; Polla, Dennis L [Roseville, MN; Maghribi, Mariam N [Davis, CA; Hamilton, Julie [Tracy, CA; Humayun, Mark S [La Canada, CA; Weiland, James D [Valencia, CA

    2012-01-28

    An image is captured or otherwise converted into a signal in an artificial vision system. The signal is transmitted to the retina utilizing an implant. The implant consists of a polymer substrate made of a compliant material such as poly(dimethylsiloxane) or PDMS. The polymer substrate is conformable to the shape of the retina. Electrodes and conductive leads are embedded in the polymer substrate. The conductive leads and the electrodes transmit the signal representing the image to the cells in the retina. The signal representing the image stimulates cells in the retina.

  7. System of fabricating a flexible electrode array

    Science.gov (United States)

    Krulevitch, Peter; Polla, Dennis L.; Maghribi, Mariam N.; Hamilton, Julie; Humayun, Mark S.; Weiland, James D.

    2010-10-12

    An image is captured or otherwise converted into a signal in an artificial vision system. The signal is transmitted to the retina utilizing an implant. The implant consists of a polymer substrate made of a compliant material such as poly(dimethylsiloxane) or PDMS. The polymer substrate is conformable to the shape of the retina. Electrodes and conductive leads are embedded in the polymer substrate. The conductive leads and the electrodes transmit the signal representing the image to the cells in the retina. The signal representing the image stimulates cells in the retina.

  8. Electrodes for 24 hours pH monitoring--a comparative study.

    OpenAIRE

    McLauchlan, G; Rawlings, J M; Lucas, M L; McCloy, R F; Crean, G P; McColl, K E

    1987-01-01

    Three pH electrodes in clinical use were examined--(1) antimony electrode with remote reference electrode (Synectics 0011), (2) glass electrode with remote reference electrode (Microelectrodes Inc. MI 506) and (3) combined glass electrode with integral reference electrode (Radiometer GK2801C). In vitro studies showed that both glass electrodes were similar and superior to the antimony electrode with respect to response time, drift, and sensitivity. The effect of the siting of the reference el...

  9. Beyond Slurry-Cast Supercapacitor Electrodes: PAN/MWNT Heteromat-Mediated Ultrahigh Capacitance Electrode Sheets

    Science.gov (United States)

    Lee, Jung Han; Kim, Jeong A.; Kim, Ju-Myung; Lee, Sun-Young; Yeon, Sun-Hwa; Lee, Sang-Young

    2017-01-01

    Supercapacitors (SCs) have garnered considerable attention as an appealing power source for forthcoming smart energy era. An ultimate challenge facing the SCs is the acquisition of higher energy density without impairing their other electrochemical properties. Herein, we demonstrate a new class of polyacrylonitrile (PAN)/multi-walled carbon tube (MWNT) heteromat-mediated ultrahigh capacitance electrode sheets as an unusual electrode architecture strategy to address the aforementioned issue. Vanadium pentoxide (V2O5) is chosen as a model electrode material to explore the feasibility of the suggested concept. The heteromat V2O5 electrode sheets are produced through one-pot fabrication based on concurrent electrospraying (for V2O5 precursor/MWNT) and electrospinning (for PAN nanofiber) followed by calcination, leading to compact packing of V2O5 materials in intimate contact with MWNTs and PAN nanofibers. As a consequence, the heteromat V2O5 electrode sheets offer three-dimensionally bicontinuous electron (arising from MWNT networks)/ion (from spatially reticulated interstitial voids to be filled with liquid electrolytes) conduction pathways, thereby facilitating redox reaction kinetics of V2O5 materials. In addition, elimination of heavy metallic foil current collectors, in combination with the dense packing of V2O5 materials, significantly increases (electrode sheet-based) specific capacitances far beyond those accessible with conventional slurry-cast electrodes.

  10. Effect of oxidation of carbon material on suspension electrodes for flow electrode capacitive deionization.

    Science.gov (United States)

    Hatzell, Kelsey B; Hatzell, Marta C; Cook, Kevin M; Boota, Muhammad; Housel, Gabrielle M; McBride, Alexander; Kumbur, E Caglan; Gogotsi, Yury

    2015-03-03

    Flow electrode deionization (FCDI) is an emerging area for continuous and scalable deionization, but the electrochemical and flow properties of the flow electrode need to be improved to minimize energy consumption. Chemical oxidation of granular activated carbon (AC) was examined here to study the role of surface heteroatoms on rheology and electrochemical performance of a flow electrode (carbon slurry) for deionization processes. Moreover, it was demonstrated that higher mass densities could be used without increasing energy for pumping when using oxidized active material. High mass-loaded flow electrodes (28% carbon content) based on oxidized AC displayed similar viscosities (∼21 Pa s) to lower mass-loaded flow electrodes (20% carbon content) based on nonoxidized AC. The 40% increased mass loading (from 20% to 28%) resulted in a 25% increase in flow electrode gravimetric capacitance (from 65 to 83 F g(-1)) without sacrificing flowability (viscosity). The electrical energy required to remove ∼18% of the ions (desalt) from of the feed solution was observed to be significantly dependent on the mass loading and decreased (∼60%) from 92 ± 7 to 28 ± 2.7 J with increased mass densities from 5 to 23 wt %. It is shown that the surface chemistry of the active material in a flow electrode effects the electrical and pumping energy requirements of a FCDI system.

  11. Etching holes in graphene supercapacitor electrodes for faster performance

    International Nuclear Information System (INIS)

    Ervin, Matthew H

    2015-01-01

    Graphene is being widely investigated as a material to replace activated carbon in supercapacitor (electrochemical capacitor) electrodes. Supercapacitors have much higher energy density, but are typically slow devices (∼0.1 Hz) compared to other types of capacitors. Here, top-down semiconductor processing has been applied to graphene-based electrodes in order to fabricate ordered arrays of holes through the graphene electrodes. This is demonstrated to increase the speed of the electrodes by reducing the ionic impedance through the electrode thickness. This approach may also be applicable to speeding up other types of devices, such as batteries and sensors, that use porous electrodes. (special)

  12. Elastomeric binders for Li-SOCl2 cell carbon electrodes

    Science.gov (United States)

    Carter, B. J.; Jeffries, B.; Yen, S. P. S.

    1987-01-01

    Nonoptimized elastomer bonded carbon electrodes made with 100-percent compressed Gulf Acetylene Black have demonstrated performance comparable to that of optimized Teflon bonded carbon electrodes, made from the same carbon, when tested at 1-10 mA/sq cm, at 24 and -26 C. The enhanced performance of elastomer bonded carbon electrodes appears to be due to the more uniform utilization of the carbon electrode to store insoluble discharge products, as compared to Teflon bonded carbon electrodes. With even minimal optimization of elastomer bonded carbon electrodes, significant improvement in Li-SOCl2 cell performance can be expected.

  13. Etching holes in graphene supercapacitor electrodes for faster performance.

    Science.gov (United States)

    Ervin, Matthew H

    2015-06-12

    Graphene is being widely investigated as a material to replace activated carbon in supercapacitor (electrochemical capacitor) electrodes. Supercapacitors have much higher energy density, but are typically slow devices (∼0.1 Hz) compared to other types of capacitors. Here, top-down semiconductor processing has been applied to graphene-based electrodes in order to fabricate ordered arrays of holes through the graphene electrodes. This is demonstrated to increase the speed of the electrodes by reducing the ionic impedance through the electrode thickness. This approach may also be applicable to speeding up other types of devices, such as batteries and sensors, that use porous electrodes.

  14. Highly sensitive determination of hydroxylamine using fused gold nanoparticles immobilized on sol-gel film modified gold electrode

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, P. [Department of Chemistry, Gandhigram Rural University, Gandhigram 624302, Dindigul, Tamilnadu (India); John, S. Abraham, E-mail: abrajohn@yahoo.co.in [Department of Chemistry, Gandhigram Rural University, Gandhigram 624302, Dindigul, Tamilnadu (India)

    2010-03-24

    We are reporting the highly sensitive determination of hydroxylamine (HA) using 2-mercapto-4-methyl-5-thiazoleacetic acid (TAA) capped fused spherical gold nanoparticles (AuNPs) modified Au electrode. The fused TAA-AuNPs were immobilized on (3-mercaptopropyl)-trimethoxysilane (MPTS) sol-gel film, which was pre-assembled on Au electrode. The immobilization of fused TAA-AuNPs on MPTS sol-gel film was confirmed by UV-vis absorption spectroscopy and atomic force microscopy (AFM). The AFM image showed that the AuNPs retained the fused spherical morphology after immobilized on sol-gel film. The fused TAA-AuNPs on MPTS modified Au electrode were used for the determination of HA in phosphate buffer (PB) solution (pH = 7.2). When compared to bare Au electrode, the fused AuNPs modified electrode not only shifted the oxidation potential of HA towards less positive potential but also enhanced its oxidation peak current. Further, the oxidation of HA was highly stable at fused AuNPs modified electrode. Using amperometric method, determination of 17.5 nM HA was achieved for the first time. Further, the current response of HA increases linearly while increasing its concentration from 17.5 nM to 22 mM and a detection limit was found to be 0.39 nM (S/N = 3). The present modified electrode was also successfully used for the determination of 17.5 nM HA in the presence of 200-fold excess of common interferents such as urea, NO{sub 2}{sup -}, NH{sub 4}{sup +}, oxalate, Mn{sup 2+}, Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Ba{sup 2+} and Cu{sup 2+}. The practical application of the present modified electrode was demonstrated by measuring the concentration of HA in ground water samples.

  15. Electrode Conduction Processes Segmented Electrode-Insulator Ratio Effects in MHD Power Generation Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pain, H. J.; Fearn, D. G.; Distefano, E. [Imperial College. London (United Kingdom)

    1966-10-15

    (a) Electrode conduction processes have been investigated using a plasma produced in an electromagnetic shock tube operating with argon at 70 {mu}mHg pressure. Complete voltage-current characteristics were obtained by the variation of load and applied voltage. These indicated the existence of two conduction regimes with a complex transition region. In the first regime the current, controlled by ion mobility, rose linearly with voltage to saturate between 10 mA and 1 A depending on conditions. Electrode contamination was significant. The second regime involved large currents controlled by electron mobility and emission from the cathode. The current again increased linearly with voltage and reached 200 A. Observation of induced voltages in transverse magnetic fields and of plasma deceleration in non-uniform fields showed that in the electromagnetic shock tube the plasma was heated predominantly by the driver discharge. Its conductivity was calculated using properties measured by a Langmuir double probe. In both regimes the plasma conductivity was also found from the gradient of the voltage current characteristics using experimental electric field fringing factors and the experimental values were compared with theory. (b) Larger-scale experiments used a combustion-driven shock tube where argon plasma flow, magnetic field and induced current flow were mutually orthogonal. The supersonic flow velocity and thermodynamic parameters of the plasma were accurately known. The electrode channel consisted of a segmented system of 12 electrode pairs with an electrode insulator ratio ranging from 1 to 21, with electrode plus insulator length remaining constant, and with maximum Hall parameter values of unity. Different electrode load combinations (Faraday and Hall generators) have been studied in measuring the power generated and the flow of longitudinal currents between adjacent electrodes. A maximum power of 0,8 MW was obtained, the power output decreasing inversely with the

  16. Electrode Conduction Processes Segmented Electrode-Insulator Ratio Effects in MHD Power Generation Experiments

    International Nuclear Information System (INIS)

    Pain, H.J.; Fearn, D.G.; Distefano, E.

    1966-01-01

    (a) Electrode conduction processes have been investigated using a plasma produced in an electromagnetic shock tube operating with argon at 70 μmHg pressure. Complete voltage-current characteristics were obtained by the variation of load and applied voltage. These indicated the existence of two conduction regimes with a complex transition region. In the first regime the current, controlled by ion mobility, rose linearly with voltage to saturate between 10 mA and 1 A depending on conditions. Electrode contamination was significant. The second regime involved large currents controlled by electron mobility and emission from the cathode. The current again increased linearly with voltage and reached 200 A. Observation of induced voltages in transverse magnetic fields and of plasma deceleration in non-uniform fields showed that in the electromagnetic shock tube the plasma was heated predominantly by the driver discharge. Its conductivity was calculated using properties measured by a Langmuir double probe. In both regimes the plasma conductivity was also found from the gradient of the voltage current characteristics using experimental electric field fringing factors and the experimental values were compared with theory. (b) Larger-scale experiments used a combustion-driven shock tube where argon plasma flow, magnetic field and induced current flow were mutually orthogonal. The supersonic flow velocity and thermodynamic parameters of the plasma were accurately known. The electrode channel consisted of a segmented system of 12 electrode pairs with an electrode insulator ratio ranging from 1 to 21, with electrode plus insulator length remaining constant, and with maximum Hall parameter values of unity. Different electrode load combinations (Faraday and Hall generators) have been studied in measuring the power generated and the flow of longitudinal currents between adjacent electrodes. A maximum power of 0,8 MW was obtained, the power output decreasing inversely with the

  17. COMMUNICATION: Toward a self-deploying shape memory polymer neuronal electrode

    Science.gov (United States)

    Sharp, Andrew A.; Panchawagh, Hrishikesh V.; Ortega, Alicia; Artale, Ryan; Richardson-Burns, Sarah; Finch, Dudley S.; Gall, Ken; Mahajan, Roop L.; Restrepo, Diego

    2006-12-01

    The widespread application of neuronal probes for chronic recording of brain activity and functional stimulation has been slow to develop partially due to long-term biocompatibility problems with existing metallic and ceramic probes and the tissue damage caused during probe insertion. Stiff probes are easily inserted into soft brain tissue but cause astrocytic scars that become insulating sheaths between electrodes and neurons. In this communication, we explore the feasibility of a new approach to the composition and implantation of chronic electrode arrays. We demonstrate that softer polymer-based probes can be inserted into the olfactory bulb of a mouse and that slow insertion of the probes reduces astrocytic scarring. We further present the development of a micromachined shape memory polymer probe, which provides a vehicle to self-deploy an electrode at suitably slow rates and which can provide sufficient force to penetrate the brain. The deployment rate and composition of shape memory polymer probes can be tailored by polymer chemistry and actuator design. We conclude that it is feasible to fabricate shape memory polymer-based electrodes that would slowly self-implant compliant conductors into the brain, and both decrease initial trauma resulting from implantation and enhance long-term biocompatibility for long-term neuronal measurement and stimulation.

  18. Development of a CMOS MEMS pressure sensor with a mechanical force-displacement transduction structure

    International Nuclear Information System (INIS)

    Cheng, Chao-Lin; Chang, Heng-Chung; Fang, Weileun; Chang, Chun-I

    2015-01-01

    This study presents a capacitive pressure sensor with a mechanical force-displacement transduction structure based on the commercially available standard CMOS process (the TSMC 0.18 μm 1P6M CMOS process). The pressure sensor has a deformable diaphragm to support a movable plate with an embedded sensing electrode. As the diaphragm is deformed by the ambient pressure, the movable plate and its embedded sensing electrode are displaced. Thus, the pressure is detected from the capacitance change between the movable and fixed electrodes. The undeformed movable electrode will increase the effective sensing area between the sensing electrodes, thereby improving the sensitivity. Experimental results show that the proposed pressure sensor with a force-displacement transducer will increase the sensitivity by 126% within the 20 kPa–300 kPa absolute pressure range. Moreover, this study extends the design to add pillars inside the pressure sensor to further increase its sensing area as well as sensitivity. A sensitivity improvement of 117% is also demonstrated for a pressure sensor with an enlarged sensing electrode (the overlap area is increased two fold). (paper)

  19. Rate of force development

    DEFF Research Database (Denmark)

    Maffiuletti, Nicola A; Aagaard, Per; Blazevich, Anthony J

    2016-01-01

    The evaluation of rate of force development during rapid contractions has recently become quite popular for characterising explosive strength of athletes, elderly individuals and patients. The main aims of this narrative review are to describe the neuromuscular determinants of rate of force devel...

  20. The forces in Nature

    CERN Multimedia

    CERN AC

    1998-01-01

    The different forces, together with a pictorial analogy of how the exchange of particles works. The table lists the relative strength of the couplings, the quanta associated with the force fields and the bodies of phenomena in which they have a dominant role.

  1. New force in nature?

    International Nuclear Information System (INIS)

    Fischbach, E.; Sudarsky, D.; Szafer, A.; Talmadge, C.; Aronson, S.H.

    1986-01-01

    We review recent experimental and theoretical work dealing with the proposed fifth force. Further analysis of the original Eoetvoes experiments has uncovered no challenges to our original assertion that these data evidence a correlation characteristic of the presence of a new coupling to baryon number or hypercharge. Various models suggest that the proposed fifth force could be accomodated naturally into the existing theoretical framework

  2. A comparison study of electrodes for neonate electrical impedance tomography

    International Nuclear Information System (INIS)

    Rahal, Mohamad; Demosthenous, Andreas; Khor, Joo Moy; Tizzard, Andrew; Bayford, Richard

    2009-01-01

    Electrical impedance tomography (EIT) is an imaging technique that has the potential to be used for studying neonate lung function. The properties of the electrodes are very important in multi-frequency EIT (MFEIT) systems, particularly for neonates, as the skin cannot be abraded to reduce contact impedance. In this work, the impedance of various clinical electrodes as a function of frequency is investigated to identify the optimum electrode type for this application. Six different types of self-adhesive electrodes commonly used in general and neonatal cardiology have been investigated. These electrodes are Ag/AgCl electrodes from the Ambu® Cardiology Blue sensors range (BR, NF and BRS), Kendall (KittyCat(TM) and ARBO®) and Philips 13953D electrodes. In addition, a textile electrode without gel from Textronics was tested on two subjects to allow comparison with the hydrogel-based electrodes. Two- and four-electrode measurements were made to determine the electrode-interface and tissue impedances, respectively. The measurements were made on the back of the forearm of six healthy adult volunteers without skin preparation with 2.5 cm electrode spacing. Impedance measurements were carried out using a Solartron SI 1260 impedance/gain-phase analyser with a frequency range from 10 Hz to 1 MHz. For the electrode-interface impedance, the average magnitude decreased with frequency, with an average value of 5 kΩ at 10 kHz and 337 Ω at 1 MHz; for the tissue impedance, the respective values were 987 Ω and 29 Ω. Overall, the Ambu BRS, Kendall ARBO® and Textronics textile electrodes gave the lowest electrode contact impedance at 1 MHz. Based on the results of the two-electrode measurements, simple RC models for the Ambu BRS and Kendall-ARBO and Textronics textile electrodes have been derived for MFEIT applications

  3. Update on Peripheral Nerve Electrodes for Closed-Loop Neuroprosthetics

    Directory of Open Access Journals (Sweden)

    Emil H. Rijnbeek

    2018-05-01

    Full Text Available In this paper various types of electrodes for stimulation and recording activity of peripheral nerves for the control of neuroprosthetic limbs are reviewed. First, an overview of interface devices for (feedback- controlled movement of a prosthetic device is given, after which the focus is on peripheral nervous system (PNS electrodes. Important electrode properties, i.e., longevity and spatial resolution, are defined based upon the usability for neuroprostheses. The cuff electrode, longitudinal intrafascicular electrodes (LIFE, transverse intrafascicular multichannel electrode (TIME, Utah slanted electrode array (USEA, and the regenerative electrode are discussed and assessed on their longevity and spatial resolution. The cuff electrode seems to be a promising electrode for the control of neuroprostheses in the near future, because it shows the best longevity and good spatial resolution and it has been used on human subjects in multiple studies. The other electrodes may be promising in the future, but further research on their longevity and spatial resolution is needed. A more quantitatively uniform study protocol used for all electrodes would allow for a proper comparison of recording and stimulation performance. For example, the discussed electrodes could be compared in a large in vivo study, using one uniform comparison protocol.

  4. Ponderomotive Forces in Cosmos

    Science.gov (United States)

    Lundin, R.; Guglielmi, A.

    2006-12-01

    This review is devoted to ponderomotive forces and their importance for the acceleration of charged particles by electromagnetic waves in space plasmas. Ponderomotive forces constitute time-averaged nonlinear forces acting on a media in the presence of oscillating electromagnetic fields. Ponderomotive forces represent a useful analytical tool to describe plasma acceleration. Oscillating electromagnetic fields are also related with dissipative processes, such as heating of particles. Dissipative processes are, however, left outside these discussions. The focus will be entirely on the (conservative) ponderomotive forces acting in space plasmas. The review consists of seven sections. In Section 1, we explain the rational for using the auxiliary ponderomotive forces instead of the fundamental Lorentz force for the study of particle motions in oscillating fields. In Section 2, we present the Abraham, Miller, Lundin-Hultqvist and Barlow ponderomotive forces, and the Bolotovsky-Serov ponderomotive drift. The hydrodynamic, quasi-hydrodynamic, and ‘`test-particle’' approaches are used for the study of ponderomotive wave-particle interaction. The problems of self-consistency and regularization are discussed in Section 3. The model of static balance of forces (Section 4) exemplifies the interplay between thermal, gravitational and ponderomotive forces, but it also introduces a set of useful definitions, dimensionless parameters, etc. We analyze the Alfvén and ion cyclotron waves in static limit with emphasis on the specific distinction between traveling and standing waves. Particular attention has been given to the impact of traveling Alfvén waves on the steady state anabatic wind that blows over the polar regions (Section~5). We demonstrate the existence of a wave-induced cold anabatic wind. We also show that, at a critical point, the ponderomotive acceleration of the wind is a factor of 3 greater than the thermal acceleration. Section 6 demonstrates various

  5. Scanning reference electrode techniques in localized corrosion

    International Nuclear Information System (INIS)

    Isaacs, H.S.; Vyas, B.

    1979-04-01

    The principles, advantages, and implementations of scanning reference electrode techniques are reviewed. Data related to pitting, intergranular corrosion, welds and stress corrosion cracking are presented. The technique locates the position of localized corrosion and can be used to monitor the development of corrosion and changes in the corrosion rate under a wide range of conditions

  6. Ultraconformable Temporary Tattoo Electrodes for Electrophysiology

    Science.gov (United States)

    Ferrari, Laura M.; Sudha, Sudha; Tarantino, Sergio; Esposti, Roberto; Bolzoni, Francesco; Cavallari, Paolo; Cipriani, Christian

    2018-01-01

    Abstract Electrically interfacing the skin for monitoring personal health condition is the basis of skin‐contact electrophysiology. In the clinical practice the use of stiff and bulky pregelled or dry electrodes, in contrast to the soft body tissues, imposes severe restrictions to user comfort and mobility while limiting clinical applications. Here, in this work dry, unperceivable temporary tattoo electrodes are presented. Customized single or multielectrode arrays are readily fabricated by inkjet printing of conducting polymer onto commercial decal transfer paper, which allows for easy transfer on the user's skin. Conformal adhesion to the skin is provided thanks to their ultralow thickness (Tattoo electrode–skin contact impedance is characterized on short‐ (1 h) and long‐term (48 h) and compared with standard pregelled and dry electrodes. The viability in electrophysiology is validated by surface electromyography and electrocardiography recordings on various locations on limbs and face. A novel concept of tattoo as perforable skin‐contact electrode, through which hairs can grow, is demonstrated, thus permitting to envision very long‐term recordings on areas with high hair density. The proposed materials and patterning strategy make this technology amenable for large‐scale production of low‐cost sensing devices. PMID:29593975

  7. Low Energy Desalination Using Battery Electrode Deionization

    KAUST Repository

    Kim, Taeyoung; Gorski, Christopher A.; Logan, Bruce

    2017-01-01

    capacities (up to 100 mg-NaCl/g-electrode, 50 mM NaCl influent), and consumed less energy than CDI. Simultaneous production of desalinated and concentrated solutions in two channels avoided a two-cycle approach needed for CDI. Stacking additional membranes

  8. A tubular electrode for radiofrequency ablation therapy

    KAUST Repository

    Antunes, Carlos Lemos Lemos Lemos

    2012-07-06

    Purpose – Due to its good mechanical and biocompatibility characteristics, nitinol SEMS is a popular endoprothesis used for relieving stricture problems in hollow organs due to carcinomas. Besides its mechanical application, SEMS can be regarded as well as potential electrode for performing RF ablation therapy on the tumor. The purpose of this work is to perform numerical and experimental analyses in order to characterize the lesion volume induced in biological tissue using this kind of tubular electrode. Design/methodology/approach – Data concerning electrical conductivity and dimension of the damaged tissue after RF ablation procedure were obtained from ex vivo samples. Next, numerical models using 3D finite element method were obtained reassembling the conditions considered at experimentation setup and results were compared. Findings – Numerical and experimental results show that a regular volume of damaged tissue can be obtained considering this type of electrode. Also, results obtained from numerical simulation are close to those obtained by experimentation. Originality/value – SEMSs, commonly used as devices to minimize obstruction problems due to the growth of tumors, may still be considered as an active electrode for RF ablation procedures. A method considering this observation is presented in this paper. Also, numerical simulation can be regarded in this case as a tool for determining the lesion volume.

  9. Micromachined Planar Supercapacitor with Interdigital Buckypaper Electrodes

    Directory of Open Access Journals (Sweden)

    Yun-Ting Chen

    2018-05-01

    Full Text Available In this work, a flexible micro-supercapacitor with interdigital planar buckypaper electrodes is presented. A simple fabrication process involving vacuum filtration method and SU-8 molding techniques is proposed to fabricate in-plane interdigital buckypaper electrodes on a membrane filter substrate. The proposed process exhibits excellent flexibility for future integration of the micro-supercapacitors (micro-SC with other electronic components. The device’s maximum specific capacitance measured using cyclic voltammetry was 107.27 mF/cm2 at a scan rate of 20 mV/s. The electrochemical stability was investigated by measuring the performance of charge-discharge at different discharge rates. Devices with different buckypaper electrode thicknesses were also fabricated and measured. The specific capacitance of the proposed device increased linearly with the buckypaper electrode thickness. The measured leakage current was approximately 9.95 µA after 3600 s. The device exhibited high cycle stability, with 96.59% specific capacitance retention after 1000 cycles. A Nyquist plot of the micro-SC was also obtained by measuring the impedances with frequencies from 1 Hz to 50 kHz; it indicated that the equivalent series resistance value was approximately 18 Ω.

  10. Nickel hydroxide modified electrodes for urea determination

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Dall´Antonia

    2007-03-01

    Full Text Available Nickel hydroxide films were prepared by electrodeposition from a solution Ni(NO32 0,05 mol L ?¹ on ITO electrodes (Tin oxide doped with Indium on PET-like plastic film, applying a current of - 0,1 A cm ?² during different time intervals between 1800 and 7200 s. The electrochemical behavior of the nickel hydroxide electrode was investigated through a cyclic voltammogram, in NaOH 1,0 mol L ?¹, where it was observed two peaks in the profile in 0,410 and 0,280 V, corresponding to redox couple Ni(II/Ni(III. A sensor for urea presenting a satisfactory answer can be obtained when, after the deposit of the film of Ni(OH2 on the electrode of nickel, it is immersed in a solution of NaOH 1,0 mol L ?¹ and applying a potential of + 0,435 V, where the maximum of the anodic current occurs in the cyclic voltammogram. Analyzing the results it can be observed that, for a range of analite concentration between 5 to 50 m mol L ?¹, the behavior is linear and the sensibility found was of 20,3 mA cm?² (mol L?¹?¹, presenting reproducibility confirming the nickel hydroxide electrodes utilization for the determination of urea.

  11. Amperometric Noise at Thin Film Band Electrodes

    DEFF Research Database (Denmark)

    Larsen, Simon T.; Heien, Michael L.; Taboryski, Rafael

    2012-01-01

    Background current noise is often a significant limitation when using constant-potential amperometry for biosensor application such as amperometric recordings of transmitter release from single cells through exocytosis. In this paper, we fabricated thin-film electrodes of gold and conductive...

  12. Reference Electrodes Based on Solid Amalgams

    Czech Academy of Sciences Publication Activity Database

    Josypčuk, Bohdan; Novotný, Ladislav

    2004-01-01

    Roč. 16, č. 3 (2004), s. 238-241 ISSN 1040-0397 Grant - others:GIT(AR) 101/02/U111/CZ Institutional research plan: CEZ:AV0Z4040901 Keywords : solid amalgam * reference electrode * voltammetry Subject RIV: CG - Electrochemistry Impact factor: 2.038, year: 2004

  13. Carbon Nanofiber Electrode Array for Neurochemical Monitoring

    Science.gov (United States)

    Koehne, Jessica E.

    2017-01-01

    A sensor platform based on vertically aligned carbon nanofibers (CNFs) has been developed. Their inherent nanometer scale, high conductivity, wide potential window, good biocompatibility and well-defined surface chemistry make them ideal candidates as biosensor electrodes. Here, we report using vertically aligned CNF as neurotransmitter recording electrodes for application in a smart deep brain stimulation (DBS) device. Our approach combines a multiplexed CNF electrode chip, developed at NASA Ames Research Center, with the Wireless Instantaneous Neurotransmitter Concentration Sensor (WINCS) system, developed at the Mayo Clinic. Preliminary results indicate that the CNF nanoelectrode arrays are easily integrated with WINCS for neurotransmitter detection in a multiplexed array format. In the future, combining CNF based stimulating and recording electrodes with WINCS may lay the foundation for an implantable smart therapeutic system that utilizes neurochemical feedback control while likely resulting in increased DBS application in various neuropsychiatric disorders. In total, our goal is to take advantage of the nanostructure of CNF arrays for biosensing studies requiring ultrahigh sensitivity, high-degree of miniaturization, and selective biofunctionalization.

  14. 1-ethanone modified carbon paste electrode

    African Journals Online (AJOL)

    a

    7.00) in cyclic voltammetry, the oxidation of L-cysteic acid at the surface of 4FEPEMCPE is occurred at a potential about 220 mV less positive than that an unmodified carbon paste electrode. The kinetic parameters such as electron transfer coefficient, α, and catalytic reaction rate constant, K/ h, were also determined using.

  15. Slotted coax as a beam electrode

    International Nuclear Information System (INIS)

    Lambertson, G.R.; Kim, K.J.; Voelker, F.V.

    1983-03-01

    The slot coupled TEM line has been employed at CERN as a pick up electrode in the GHz range. It is a compact and broad band device, and will be quite attractive if the coupling efficiency is competitive with an array of quarter wave loops. In this paper, we study various properties of such a structure

  16. 21 CFR 886.1220 - Corneal electrode.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Corneal electrode. 886.1220 Section 886.1220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL... to the cornea to provide data showing the changes in electrical potential in the retina after...

  17. Fluctuations at electrode-YSZ interfaces

    DEFF Research Database (Denmark)

    Jacobsen, T.; Hansen, K.V.; Skou, E.

    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...

  18. Site Selection for Hvdc Ground Electrodes

    Science.gov (United States)

    Freire, P. F.; Pereira, S. Y.

    2014-12-01

    High-Voltage Direct Current (HVDC) transmission systems are composed of a bipole transmission line with a converter substation at each end. Each substation may be equipped with a HVDC ground electrode, which is a wide area (up to 1 km Ø) and deep (from 3 to 100m) electrical grounding. When in normal operation, the ground electrode will dissipate in the soil the unbalance of the bipole (~1.5% of the rated current). When in monopolar operation with ground return, the HVDC electrode will inject in the soil the nominal pole continuous current, of about 2000 to 3000 Amperes, continuously for a period up to a few hours. HVDC ground electrodes site selection is a work based on extensive geophysical and geological surveys, in order to attend the desired design requirements established for the electrodes, considering both its operational conditions (maximum soil temperature, working life, local soil voltage gradients etc.) and the interference effects on the installations located up to 50 km away. This poster presents the geophysical investigations conducted primarily for the electrodes site selection, and subsequently for the development of the crust resistivity model, which will be used for the interference studies. A preliminary site selection is conducted, based on general geographical and geological criteria. Subsequently, the geology of each chosen area is surveyed in detail, by means of electromagnetic/electrical geophysical techniques, such as magnetotelluric (deep), TDEM (near-surface) and electroresistivity (shallow). Other complementary geologic and geotechnical surveys are conducted, such as wells drilling (for geotechnical characterization, measurement of the water table depth and water flow, and electromagnetic profiling), and soil and water sampling (for measurement of thermal parameters and evaluation of electrosmosis risk). The site evaluation is a dynamic process along the surveys, and some sites will be discarded. For the two or three final sites, the

  19. Miniature large range multi-axis force-torque sensor for biomechanical applications

    International Nuclear Information System (INIS)

    Brookhuis, R A; Sanders, R G P; Ma, K; Lammerink, T S J; De Boer, M J; Krijnen, G J M; Wiegerink, R J

    2015-01-01

    A miniature force sensor for the measurement of forces and moments at a human fingertip is designed and realized. Thin silicon pillars inside the sensor provide in-plane guidance for shear force measurement and provide the spring constant in normal direction. A corrugated silicon ring around the force sensitive area provides the spring constant in shear direction and seals the interior of the sensor. To detect all load components, capacitive read-out is used. A novel electrode pattern results in a large shear force sensitivity. The fingertip force sensor has a wide force range of up to 60 N in normal direction, ± 30 N in shear direction and a torque range of ± 25 N mm. (paper)

  20. All conducting polymer electrodes for asymmetric solid-state supercapacitors

    KAUST Repository

    Kurra, Narendra; Wang, Ruiqi; Alshareef, Husam N.

    2015-01-01

    electrode material. In addition, the high stability of PEDOT in its oxidised state makes it capable to exhibit electrochemical activity in a wide potential window. This can qualify PEDOT to be used as a negative electrode in fabricating asymmetric solid

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    Electrode grounding resistance is a major factor affecting measurement quality in electric resistivity tomography (ERT) measurements for cryospheric applications. Still, little information is available on grounding resistances in the geophysical literature, mainly because it is difficult to measure....... 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...

  2. Laser-Scribed Graphene Electrodes for Aptamer-Based Biosensing

    KAUST Repository

    Fenzl, Christoph; Nayak, Pranati; Hirsch, Thomas; Wolfbeis, Otto S.; Alshareef, Husam N.; Baeumner, Antje J.

    2017-01-01

    (LSG) electrodes are demonstrated here as highly sensitive and reliable biosensor transducers in blood serum analysis. These flexible electrodes with large electrochemical surface areas were fabricated using a direct-write laser process on polyimide foils. A

  3. Reliable reference electrodes for lithium-ion batteries

    KAUST Repository

    La Mantia, F.; Wessells, C.D.; Deshazer, H.D.; Cui, Yi

    2013-01-01

    Despite the high attention drawn to the lithium-ion batteries by the scientific and industrial community, most of the electrochemical characterization is carried out using poor reference electrodes or even no reference electrode. In this case

  4. Spinal cord electrophysiology II: extracellular suction electrode fabrication.

    Science.gov (United States)

    Garudadri, Suresh; Gallarda, Benjamin; Pfaff, Samuel; Alaynick, William

    2011-02-20

    Development of neural circuitries and locomotion can be studied using neonatal rodent spinal cord central pattern generator (CPG) behavior. We demonstrate a method to fabricate suction electrodes that are used to examine CPG activity, or fictive locomotion, in dissected rodent spinal cords. The rodent spinal cords are placed in artificial cerebrospinal fluid and the ventral roots are drawn into the suction electrode. The electrode is constructed by modifying a commercially available suction electrode. A heavier silver wire is used instead of the standard wire given by the commercially available electrode. The glass tip on the commercial electrode is replaced with a plastic tip for increased durability. We prepare hand drawn electrodes and electrodes made from specific sizes of tubing, allowing consistency and reproducibility. Data is collected using an amplifier and neurogram acquisition software. Recordings are performed on an air table within a Faraday cage to prevent mechanical and electrical interference, respectively.

  5. Fabrication and Characterisation of Membrane-Based Gold Electrodes

    DEFF Research Database (Denmark)

    Bakmand, Tanya; Kwasny, Dorota; Dimaki, Maria

    2015-01-01

    This work presents a versatile, membrane based electrochemical sensor with thin film electrodes fabricated through Ebeam evaporation directly on porous materials (membranes). Here, the fabrication of the electrodes is described along with possible methods for integration in fluidic systems...

  6. Structure and Modification of Electrode Materials for Protein Electrochemistry.

    Science.gov (United States)

    Jeuken, Lars J C

    The interactions between proteins and electrode surfaces are of fundamental importance in bioelectrochemistry, including photobioelectrochemistry. In order to optimise the interaction between electrode and redox protein, either the electrode or the protein can be engineered, with the former being the most adopted approach. This tutorial review provides a basic description of the most commonly used electrode materials in bioelectrochemistry and discusses approaches to modify these surfaces. Carbon, gold and transparent electrodes (e.g. indium tin oxide) are covered, while approaches to form meso- and macroporous structured electrodes are also described. Electrode modifications include the chemical modification with (self-assembled) monolayers and the use of conducting polymers in which the protein is imbedded. The proteins themselves can either be in solution, electrostatically adsorbed on the surface or covalently bound to the electrode. Drawbacks and benefits of each material and its modifications are discussed. Where examples exist of applications in photobioelectrochemistry, these are highlighted.

  7. Single-molecule force-conductance spectroscopy of hydrogen-bonded complexes

    DEFF Research Database (Denmark)

    Pirrotta, Alessandro; De Vico, Luca; Solomon, Gemma C.

    2017-01-01

    to inform about molecular recognition events at the single-molecule limit. For this, we consider the force-conductance characteristics of a prototypical class of hydrogen bonded bimolecular complexes sandwiched between gold electrodes. The complexes consist of derivatives of a barbituric acid and a Hamilton...... is mechanically manipulated. The implication is that force and conductance provide complementary information about the evolution of molecules in junctions that can be used to interrogate basic structure-transport relations at the single-molecule limit....

  8. Mathematical modeling and calculation of forced resonant vibrations of composite electromechanical system

    OpenAIRE

    Ластівка, Іван Олексійович

    2014-01-01

    Resonant vibrations of composite electromechanical symmetric three-element system “metal plate - piezoceramic cylindrical panels” are considered. Forced vibrations are made under the influence of external alternating electric field, supplied to the electrodes of piezoceramic segments of cylindrical panels, previously polarized in the tangential direction.Based on the improved theory, such as the S.P. Timoshenko’s, the system of differential equations of forced vibrations of the system, taking...

  9. Domestic wastewater treatment using multi-electrode continuous flow MFCs with a separator electrode assembly design

    KAUST Repository

    Ahn, Yongtae; Logan, Bruce E.

    2012-01-01

    Treatment of domestic wastewater using microbial fuel cells (MFCs) will require reactors with multiple electrodes, but this presents unique challenges under continuous flow conditions due to large changes in the chemical oxygen demand (COD

  10. Multi-electrode double layer capacitor having single electrolyte seal and aluminum-impregnated carbon cloth electrodes

    Science.gov (United States)

    Farahmandi, C. Joseph; Dispennette, John M.; Blank, Edward; Kolb, Alan C.

    1999-01-19

    A single cell, multi-electrode high performance double layer capacitor includes first and second flat stacks of electrodes adapted to be housed in a closeable two-part capacitor case which includes only a single electrolyte seal. Each electrode stack has a plurality of electrodes connected in parallel, with the electrodes of one stack being interleaved with the electrodes of the other stack to form an interleaved stack, and with the electrodes of each stack being electrically connected to respective capacitor terminals. A porous separator sleeve is inserted over the electrodes of one stack before interleaving to prevent electrical shorts between the electrodes. The electrodes are made by folding a compressible, low resistance, aluminum-impregnated carbon cloth, made from activated carbon fibers, around a current collector foil, with a tab of the foils of each electrode of each stack being connected in parallel and connected to the respective capacitor terminal. The height of the interleaved stack is somewhat greater than the inside height of the closed capacitor case, thereby requiring compression of the interleaved electrode stack when placed inside of the case, and thereby maintaining the interleaved electrode stack under modest constant pressure. The closed capacitor case is filled with an electrolytic solution and sealed. A preferred electrolytic solution is made by dissolving an appropriate salt into acetonitrile (CH.sub.3 CN). In one embodiment, the two parts of the capacitor case are conductive and function as the capacitor terminals.

  11. [Verification of skin paste electrodes used in wireless polysomnography].

    Science.gov (United States)

    Ma, Y D; Huang, D; Chen, Y F; Jiang, H Y; Liu, J H; Sun, H Q; Li, Z H

    2018-04-18

    To explore an electrode suitable for wireless portable sleep monitoring equipment and analyze the result of the signals of electrooculogram (EOG) and electroencephalography (EEG) collected by this kind of flexible electrodes. The flexible electrodes were prepared by microelectromechanical systems (MEMS) technology. This kind of electrodes consisted parylene, chromium, and gold. Parylene, the flexible substrate of this kind of flexible electrodes, was of biocompatibility. Between parylene and gold there was an adhesion layer of chromium, which connected parylene and gold tightly. Then the flexible electrodes were stuck to medical adhesive tape. The electrodes were designed and made into a grid to make sure that the medical adhesive tape could tape on the skin tightly, so that the contact impedance between the electrodes and the skin would be reduced. Then the alternating current impedance of the electrode were tested by the CHI660E electrochemical workstation after the electrode was achieved. To make sure that this kind of electrodes could be used in EOG monitoring, the electrodes were connected to a wireless signal acquisition suite containing special biological signal acquisition and digital processing chip to gather different sites around the eyes and the electrical signals of different directions of the eye movements, then analyzed the signal-to-noise ratio of the EOG. At the end, the Philips A6 polysomnography was used to compare the noise amplitude of the EEG signals collected by the flexible electrode and the gold cup electrode. The electrodes stuck to the skin tightly, and these electrodes could collect signals that we wanted while the experiment was performed. The alternating current impedance of the flexible electrode was between 4 kΩ and 13 kΩ while with the frequency of alternating current under 100 Hz, most EEG signal frequencies were at this range. The EOG signals collected by the flexible electrodes were in line with the clinical requirements. The

  12. In-electrode vs. on-electrode: ultrasensitive Faraday cage-type electrochemiluminescence immunoassay.

    Science.gov (United States)

    Guo, Zhiyong; Sha, Yuhong; Hu, Yufang; Wang, Sui

    2016-03-28

    A new-concept of an "in-electrode" Faraday cage-type electrochemiluminescence immunoassay (ECLIA) method for the ultrasensitive detection of neurotensin (NT) was reported with capture antibody (Ab1)-nanoFe3O4@graphene (GO) and detector antibody (Ab2)&N-(4-aminobutyl)-N-ethylisoluminol (ABEI)@GO, which led to about 1000-fold improvement in sensitivity by extending the Helmholtz plane (OHP) of the proposed electrode assembly effectively.

  13. Organic light emitting diode with light extracting electrode

    Energy Technology Data Exchange (ETDEWEB)

    Bhandari, Abhinav; Buhay, Harry

    2017-04-18

    An organic light emitting diode (10) includes a substrate (20), a first electrode (12), an emissive active stack (14), and a second electrode (18). At least one of the first and second electrodes (12, 18) is a light extracting electrode (26) having a metallic layer (28). The metallic layer (28) includes light scattering features (29) on and/or in the metallic layer (28). The light extracting features (29) increase light extraction from the organic light emitting diode (10).

  14. Liquid and gel electrodes for transverse free flow electrophoresis

    Science.gov (United States)

    Jung, Byoungsok; Rose, Klint A; Shusteff, Maxim; Persat, Alexandre; Santiago, Juan

    2015-04-07

    The present invention provides a mechanism for separating or isolating charged particles under the influence of an electric field without metal electrodes being in direct contact with the sample solution. The metal electrodes normally in contact with the sample are replaced with high conductivity fluid electrodes situated parallel and adjacent to the sample. When the fluid electrodes transmit the electric field across the sample, particles within the sample migrate according to their electrophoretic mobility.

  15. Perovskite electrodes and method of making the same

    Science.gov (United States)

    Seabaugh, Matthew M.; Swartz, Scott L.

    2005-09-20

    The invention relates to perovskite oxide electrode materials in which one or more of the elements Mg, Ni, Cu, and Zn are present as minority components that enhance electrochemical performance, as well as electrode products with these compositions and methods of making the electrode materials. Such electrodes are useful in electrochemical system applications such as solid oxide fuel cells, ceramic oxygen generation systems, gas sensors, ceramic membrane reactors, and ceramic electrochemical gas separation systems.

  16. Electro-oxidation of chlorophenols on poly(3,4-ethylenedioxythiophene)-poly(styrene sulphonate) composite electrode

    International Nuclear Information System (INIS)

    Pigani, L.; Musiani, M.; Pirvu, C.; Terzi, F.; Zanardi, C.; Seeber, R.

    2007-01-01

    The electrochemical behaviour of chlorinated phenols on Pt/poly(3,4-ethylenedioxy)thiophene,LiClO 4 and on Pt/poly(3,4-ethylenedioxy)thiophene,poly(sodium-4-styrenesulphonate) electrodes has been investigated in phosphate buffer solution. Poly(sodium-4-styrenesulphonate) exerts remarkable effect against the electrode fouling induced by oxidation of chlorophenols, allowing us to record the relevant anodic response even after repeated potential cycles. Hypotheses about the role exerted by poly(sodium 4-styrenesulphonate) are made, on the basis of evidences provided by several techniques, such as cyclic voltammetry, electrochemical impedance spectroscopy, electrochemical microgravimetry and atomic force microscopy. Thanks to the fact that different chlorophenols show differences in the voltammetric responses, depending on number and position of the chloro substituents on the aromatic ring, applications of the modified electrode in the analysis of mixtures of chlorinated phenols are possible

  17. OOTW Force Design Tools

    Energy Technology Data Exchange (ETDEWEB)

    Bell, R.E.; Hartley, D.S.III; Packard, S.L.

    1999-05-01

    This report documents refined requirements for tools to aid the process of force design in Operations Other Than War (OOTWs). It recommends actions for the creation of one tool and work on other tools relating to mission planning. It also identifies the governmental agencies and commands with interests in each tool, from whom should come the user advisory groups overseeing the respective tool development activities. The understanding of OOTWs and their analytical support requirements has matured to the point where action can be taken in three areas: force design, collaborative analysis, and impact analysis. While the nature of the action and the length of time before complete results can be expected depends on the area, in each case the action should begin immediately. Force design for OOTWs is not a technically difficult process. Like force design for combat operations, it is a process of matching the capabilities of forces against the specified and implied tasks of the operation, considering the constraints of logistics, transport and force availabilities. However, there is a critical difference that restricts the usefulness of combat force design tools for OOTWs: the combat tools are built to infer non-combat capability requirements from combat capability requirements and cannot reverse the direction of the inference, as is required for OOTWs. Recently, OOTWs have played a larger role in force assessment, system effectiveness and tradeoff analysis, and concept and doctrine development and analysis. In the first Quadrennial Defense Review (QDR), each of the Services created its own OOTW force design tool. Unfortunately, the tools address different parts of the problem and do not coordinate the use of competing capabilities. These tools satisfied the immediate requirements of the QDR, but do not provide a long-term cost-effective solution.

  18. Microstructure of thin film platinum electrodes on yttrium stabilized zirconia prepared by sputter deposition

    Energy Technology Data Exchange (ETDEWEB)

    Toghan, Arafat, E-mail: arafat.toghan@pci.uni-hannover.de [Institute of Physical Chemistry and Electrochemistry, Leibniz University of Hannover, Callinstrasse 3-3a, D-30167 Hannover (Germany); Khodari, M. [Chemistry Department, Faculty of Science, South Valley University, Qena, 83523 (Egypt); Steinbach, F.; Imbihl, R. [Institute of Physical Chemistry and Electrochemistry, Leibniz University of Hannover, Callinstrasse 3-3a, D-30167 Hannover (Germany)

    2011-09-01

    (111) oriented thin film Pt electrodes were prepared on single crystals of yttrium-stabilized zirconia (YSZ) by sputter deposition of platinum. The electrodes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), energy-dispersive X-ray analysis (EDX), atomic force microscopy (AFM) and by profilometry. SEM images of the as-sputtered platinum film show a compact amorphous Pt film covering uniformly the substrate. Upon annealing at 1123 K, gaps and pores at the interface develop leading to a partial dewetting of the Pt film. Increasing the annealing temperature to 1373 K transforms the polycrystalline Pt film into single crystalline grains exhibiting a (111) orientation towards the substrate.

  19. Enantioanalysis of S-deprenyl using enantioselective, potentiometric membrane electrodes based on C60 derivatives

    International Nuclear Information System (INIS)

    Stefan-van Staden, Raluca-Ioana

    2010-01-01

    Enantioselective, potentiometric membrane electrodes based on (1,2-methanofullerene C 60 )-61-carboxylic acid, diethyl (1,2-methanofullerene C 60 )-61-61-dicarboxylate and tert-butyl (1,2-methanofullerene C 60 )-61-carboxylic acid were proposed for the enantioanalysis of S-deprenyl in pharmaceutical compounds. Molecular modeling calculations were performed to prove the reliability of the proposed electrodes. The different characteristics involved in this analysis were explained, namely (i) the stability of each molecule using total energy, hardness and dipole moment, and (ii) the explanation of the mechanism of interaction using intermolecular forces (moderate hydrogen bond interactions), atomic charges and electrostatic potential. Electronic structures as well as molecular interaction have been investigated using Hartree-Fock theory, 3-21G(*) basis set. Stability and feasibility of all the generated structures were supported by their respective energy minima and fundamental frequencies.

  20. Electrochemical polymerization of an aniline-terminated self-assembled monolayer on indium tin oxide electrodes and its effect on polyaniline electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Silva, Rodolfo [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, UAEM. Av. Universidad 1001Col. Chamilpa, CP 62210, Cuernavaca, Mor. (Mexico)], E-mail: rcruzsilva@uaem.mx; Nicho, Maria E.; Resendiz, Mary C.; Agarwal, Vivechana [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, UAEM. Av. Universidad 1001Col. Chamilpa, CP 62210, Cuernavaca, Mor. (Mexico); Castillon, Felipe F.; Farias, Mario H. [Centro de Ciencias de la Materia Condensada de la UNAM, Apdo. Postal 2681 C.P. 22800 Ensenada, B.C. (Mexico)

    2008-06-02

    Indium tin oxide (ITO) transparent electrodes were surface modified by a self-assembled monolayer of N-phenyl-{gamma}-aminopropyl-trimethoxysilane (PAPTS). Cyclic voltammetry of the PAPTS monolayer in aniline-free aqueous electrolyte showed the typical shape of a surface-confined monomer, due to the oxidation of the aniline moieties. This process resulted in a two-dimensional polyaniline film with uniform thickness of 1.3 nm, as measured by atomic force microscopy. X-ray photoelectron and UV-visible spectroscopic techniques confirm the formation of a conjugated polymer film. The influence of the surface modification of ITO electrodes on polyaniline electrochemical deposition was also studied. The initial oxidation rate of aniline increased in the PAPTS-modified ITO electrodes, although the overall film formation rate was lower than that of unmodified ITO electrodes. The morphology of the electrodeposited polyaniline films on PAPTS-modified and unmodified ITO electrodes was studied by atomic force microscopy. Films of smaller grain were grown in the PAPTS-modified ITO as compared to films grown on unmodified ITO. A blocking effect due to the propyl spacer is proposed to explain the reduced electron transfer in PAPTS-modified electrodes.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

    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-3 α ,12 α -bis(4-trifluoroacetylbenzoyloxy)-5 β -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. (paper)

  2. Ultrahigh PEMFC performance of a thin-film, dual-electrode assembly with tailored electrode morphology.

    Science.gov (United States)

    Jung, Chi-Young; Kim, Tae-Hyun; Yi, Sung-Chul

    2014-02-01

    A dual-electrode membrane electrode assembly (MEA) for proton exchange membrane fuel cells with enhanced polarization under zero relative humidity (RH) is fabricated by introducing a phase-separated morphology in an agglomerated catalyst layer of Pt/C (platinum on carbon black) and Nafion. In the catalyst layer, a sufficient level of phase separation is achieved by dispersing the Pt catalyst and the Nafion dispersion in a mixed-solvent system (propane-1,2,3-triol/1-methyl-2-pyrrolidinone).The high polymer chain mobility results in improved water uptake and regular pore-size distribution with small pore diameters. The electrochemical performance of the dual-film electrode assembly with different levels of phase separation is compared to conventional electrode assemblies. As a result, good performance at 0 % RH is obtained because self-humidification is dramatically improved by attaching this dense and phase-separated catalytic overlayer onto the conventional catalyst layer. A MEA prepared using the thin-film, dual-layered electrode exhibits 39-fold increased RH stability and 28-fold improved start-up recovery time during the on-off operation relative to the conventional device. We demonstrate the successful operation of the dual-layered electrode comprised of discriminatively phase-separated agglomerates with an ultrahigh zero RH fuel-cell performance reaching over 95 % performance of a fully humidified MEA. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Ozone production by an atmospheric pulsed discharge with pre-ionization electrodes and partly covered electrode

    International Nuclear Information System (INIS)

    Kaneda, S.; Shimosaki, M.; Hayashi, N.; Ihara, S.; Satoh, S.; Yamabe, C.

    2002-01-01

    In this paper, results on ozone production by atmospheric pulsed discharge, are reported. In the research, two types of ozonizer (Type I and Type II) have been used to investigate improvements of ozone concentration and production efficiency. The ozonizer has plane-to-plane metal electrodes structure, and pre-ionization electrodes are placed on the high voltage electrodes (Type I). In Type II, the surface of grounded electrode with 20 mm of width is covered partly by dielectric (thin rubber) with 11 mm of width, while the geometry of both metal electrodes is same to Type I. In the case of Type I, maximum concentration of about 100 ppm and maximum yield of 70 g/kWh were obtained at input power of 0.3 W. On the other hands, in the case of Type II, 800 ppm and 100 g/kWh were obtained at input power of 1.5 W. It was found that the ozone concentration and production yield were improved by using electrode covered by dielectric. (author)

  4. Forced magnetic reconnection

    Science.gov (United States)

    Vekstein, G.

    2017-10-01

    This is a tutorial-style selective review explaining basic concepts of forced magnetic reconnection. It is based on a celebrated model of forced reconnection suggested by J. B. Taylor. The standard magnetohydrodynamic (MHD) theory of this process has been pioneered by Hahm & Kulsrud (Phys. Fluids, vol. 28, 1985, p. 2412). Here we also discuss several more recent developments related to this problem. These include energetics of forced reconnection, its Hall-mediated regime, and nonlinear effects with the associated onset of the secondary tearing (plasmoid) instability.

  5. Bi-Force

    DEFF Research Database (Denmark)

    Sun, Peng; Speicher, Nora K; Röttger, Richard

    2014-01-01

    of pairwise similarities. We first evaluated the power of Bi-Force to solve dedicated bicluster editing problems by comparing Bi-Force with two existing algorithms in the BiCluE software package. We then followed a biclustering evaluation protocol in a recent review paper from Eren et al. (2013) (A...... comparative analysis of biclustering algorithms for gene expressiondata. Brief. Bioinform., 14:279-292.) and compared Bi-Force against eight existing tools: FABIA, QUBIC, Cheng and Church, Plaid, BiMax, Spectral, xMOTIFs and ISA. To this end, a suite of synthetic datasets as well as nine large gene expression...

  6. 21 CFR 876.1400 - Stomach pH electrode.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH (hydrogen...

  7. 21 CFR 870.3720 - Pacemaker electrode function tester.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pacemaker electrode function tester. 870.3720... (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Prosthetic Devices § 870.3720 Pacemaker electrode function tester. (a) Identification. A pacemaker electrode function tester is a device which is...

  8. Diffuse charge and Faradaic reactions in porous electrodes

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Yu, F.; Bazant, M.Z.

    2011-01-01

    Porous electrodes instead of flat electrodes are widely used in electrochemical systems to boost storage capacities for ions and electrons, to improve the transport of mass and charge, and to enhance reaction rates. Existing porous electrode theories make a number of simplifying assumptions: (i) The

  9. Chromatic aberrations of two-electrode transaxial mirrors

    International Nuclear Information System (INIS)

    Bejzina, L.G.; Karetskaya, S.P.

    1991-01-01

    Second order chromatic aberrations of electrostatic two-electrode transaxial mirrors in case the beam axial trajectory of charged particles is curvilinear are considered. Interrelations between coefficients of linear and angular chromatic aberrations are determined. Values of these coefficients for concave and convex transaxial mirrors with plane electrodes in dependence on potential ratio on electrodes by different onnular clearance radii are presented

  10. EUGENOL POLYMER MODIFIED TITANIUM ELECTRODE FOR THE ANALYSIS OF CARBOCYSTEINE

    OpenAIRE

    S. EL QOUATLI; R. T. NGONO; R. NAJIH; A. CHTAINI

    2012-01-01

    A eugenol polymer immobilized electrode was developed for the assay of the carbocysteine compound. The electrochemical sensor was made by in situ electropolymerization of eugenol at titanium electrode. Cyclic voltamperometry at prepared electrode permitted to point out a reversible pattern for carbocysteine electrooxidation.

  11. EUGENOL POLYMER MODIFIED TITANIUM ELECTRODE FOR THE ANALYSIS OF CARBOCYSTEINE

    Directory of Open Access Journals (Sweden)

    S. EL QOUATLI

    2012-06-01

    Full Text Available A eugenol polymer immobilized electrode was developed for the assay of the carbocysteine compound. The electrochemical sensor was made by in situ electropolymerization of eugenol at titanium electrode. Cyclic voltamperometry at prepared electrode permitted to point out a reversible pattern for carbocysteine electrooxidation.

  12. High power and high energy electrodes using carbon nanotubes

    Science.gov (United States)

    Martini, Fabrizio; Brambilla, Nicolo Michele; Signorelli, Riccardo

    2015-04-07

    An electrode useful in an energy storage system, such as a capacitor, includes an electrode that includes at least one to a plurality of layers of compressed carbon nanotube aggregate. Methods of fabrication are provided. The resulting electrode exhibits superior electrical performance in terms of gravimetric and volumetric power density.

  13. A method and an electrode for excitation of a plasma

    International Nuclear Information System (INIS)

    Glejboel, K.

    1998-01-01

    The method for excitation of a plasma comprises the step of subjecting a gas to an electric field generated by an electrode system. Each of 3 to 30 electrodes are connected to one of three specified AC voltages. The frequency is preferably between 50 and 60 Hz. The invention also concerns an electrode system for carrying out the method. 3 figs

  14. A novel electrochemical sensor for the analysis of β-agonists: The poly(acid chrome blue K)/graphene oxide-nafion/glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Xiaoyun [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Ni, Yongnian, E-mail: ynni@ncu.edu.cn [State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047 (China); Department of Chemistry, Nanchang University, Nanchang 330031 (China); Kokot, Serge, E-mail: s.kokot@qut.edu.au [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane 4001 (Australia)

    2013-09-15

    Graphical abstract: A new modified electrode was constructed by the electro-polymerization of acid chrome blue K (ACBK) at a graphene-nafion modified glassy carbon electrode (GCE). The novel electrode was successfully employed for the analysis of eight β-agonist analytes with high sensitivity. -- Highlights: • Construction of the poly-ACBK/graphene-nafion/GCE. •The modified electrode showed high sensitivity for the analysis of the β-agonists. • A novel method was successfully developed for the analysis of clenbuterol in pork. • Research provided a new method of constructing electrodes for biological analysis. -- Abstract: A novel modified electrode was constructed by the electro-polymerization of 4,5-dihydroxy-3-[(2-hydroxy-5-sulfophenyl)azo]-2,7-naphthalenedisulfonic acid trisodium salt (acid chrome blue K (ACBK)) at a graphene oxide (GO)-nafion modified glassy carbon electrode (GCE). The characterization of an electrochemically synthesized poly-ACBK/GO-nafion film was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), atomic force microscopy (AFM) and scanning electron microscopy (SEM) techniques, and the results were interpreted and compared at each stage of the electrode construction. Electrochemical oxidation of eight β-agonists – clenbuterol, salbutamol, terbutaline, ractopamine, dopamine, dobutamine, adrenaline, and isoprenaline, was investigated by CV at the different electrodes. At the poly-ACBK/GO-nafion/GCE, the linear sweep voltammetry peak currents of the eight β-agonists increased linearly with their concentrations in the range of 1.0–36.0 ng mL{sup −1}, respectively, and their corresponding limits of detection (LODs) were within the 0.58–1.46 ng mL{sup −1} range. This electrode showed satisfactory reproducibility and stability, and was used successfully for the quantitative analysis of clenbuterol in pork samples.

  15. Intraneural stimulation using wire-microelectrode arrays: analysis of force steps in recruitment curves

    NARCIS (Netherlands)

    Smit, J.P.A.; Rutten, Wim; Boom, H.B.K.

    1996-01-01

    In acute experiments on six Wistar rats, a wire-microelectrode array was inserted into the common peroneal nerve. A 5-channel array and a 24-channel array were available. Each electrode in the array was used to generate a twitch contraction force recruitment curve for the extensor digitorum longus

  16. Creating virtual electrodes with 2D current steering

    Science.gov (United States)

    Spencer, Thomas C.; Fallon, James B.; Shivdasani, Mohit N.

    2018-06-01

    Objective. Current steering techniques have shown promise in retinal prostheses as a way to increase the number of distinct percepts elicitable without increasing the number of implanted electrodes. Previously, it has been shown that ‘virtual’ electrodes can be created between simultaneously stimulated electrode pairs, producing unique cortical response patterns. This study investigated whether virtual electrodes could be created using 2D current steering, and whether these virtual electrodes can produce cortical responses with predictable spatial characteristics. Approach. Normally-sighted eyes of seven adult anaesthetised cats were implanted with a 42-channel electrode array in the suprachoroidal space and multi-unit neural activity was recorded from the visual cortex. Stimuli were delivered to individual physical electrodes, or electrodes grouped into triangular, rectangular, and hexagonal arrangements. Varying proportions of charge were applied to each electrode in a group to ‘steer’ current and create virtual electrodes. The centroids of cortical responses to stimulation of virtual electrodes were compared to those evoked by stimulation of single physical electrodes. Main results. Responses to stimulation of groups of up to six electrodes with equal ratios of charge on each electrode resulted in cortical activation patterns that were similar to those elicited by the central physical electrode (centroids: RM ANOVA on ranks, p  >  0.05 neural spread: one-way ANOVA on Ranks, p  >  0.05). We were also able to steer the centroid of activation towards the direction of any of the electrodes of the group by applying a greater charge to that electrode, but the movement in the centroid was not found to be significant. Significance. The results suggest that current steering is possible in two dimensions between up to at least six electrodes, indicating it may be possible to increase the number of percepts in patients without increasing the number

  17. Institutionalizing Security Force Assistance

    National Research Council Canada - National Science Library

    Binetti, Michael R

    2008-01-01

    .... It looks at the manner in which security assistance guidance is developed and executed. An examination of national level policy and the guidance from senior military and civilian leaders highlights the important role of Security Force Assistance...

  18. Hanscom Air Force Base

    Data.gov (United States)

    Federal Laboratory Consortium — MIT Lincoln Laboratory occupies 75 acres (20 acres of which are MIT property) on the eastern perimeter of Hanscom Air Force Base, which is at the nexus of Lexington,...

  19. Packing force data correlations

    International Nuclear Information System (INIS)

    Heiman, S.M.

    1994-01-01

    One of the issues facing valve maintenance personnel today deals with an appropriate methodology for installing and setting valve packing that will minimize leak rates, yet ensure functionality of the the valve under all anticipated operating conditions. Several variables can affect a valve packing's ability to seal, such as packing bolt torque, stem finish, and lubrication. Stem frictional force can be an excellent overall indicator of some of the underlying conditions that affect the sealing characteristics of the packing and the best parameter to use when adjusting the packing. This paper addresses stem friction forces, analytically derives the equations related to these forces, presents a methodology for measuring these forces on valve stems, and attempts to correlate the data directly to the underlying variables

  20. Expeditionary Warfare- Force Protection

    National Research Council Canada - National Science Library

    Higgins, Eric

    2004-01-01

    In 2003, the Systems Engineering and Analysis students were tasked to develop a system of systems conceptual solution to provide force protection for the Sea Base conceptualized in the 2002 Expeditionary Warfare study...

  1. Controlling cation segregation in perovskite-based electrodes for high electro-catalytic activity and durability.

    Science.gov (United States)

    Li, Yifeng; Zhang, Wenqiang; Zheng, Yun; Chen, Jing; Yu, Bo; Chen, Yan; Liu, Meilin

    2017-10-16

    Solid oxide cell (SOC) based energy conversion systems have the potential to become the cleanest and most efficient systems for reversible conversion between electricity and chemical fuels due to their high efficiency, low emission, and excellent fuel flexibility. Broad implementation of this technology is however hindered by the lack of high-performance electrode materials. While many perovskite-based materials have shown remarkable promise as electrodes for SOCs, cation enrichment or segregation near the surface or interfaces is often observed, which greatly impacts not only electrode kinetics but also their durability and operational lifespan. Since the chemical and structural variations associated with surface enrichment or segregation are typically confined to the nanoscale, advanced experimental and computational tools are required to probe the detailed composition, structure, and nanostructure of these near-surface regions in real time with high spatial and temporal resolutions. In this review article, an overview of the recent progress made in this area is presented, highlighting the thermodynamic driving forces, kinetics, and various configurations of surface enrichment and segregation in several widely studied perovskite-based material systems. A profound understanding of the correlation between the surface nanostructure and the electro-catalytic activity and stability of the electrodes is then emphasized, which is vital to achieving the rational design of more efficient SOC electrode materials with excellent durability. Furthermore, the methodology and mechanistic understanding of the surface processes are applicable to other materials systems in a wide range of applications, including thermo-chemical photo-assisted splitting of H 2 O/CO 2 and metal-air batteries.

  2. Sulfur based electrode materials for secondary batteries

    Science.gov (United States)

    Hao, Yong

    Developing next generation secondary batteries has attracted much attention in recent years due to the increasing demand of high energy and high power density energy storage for portable electronics, electric vehicles and renewable sources of energy. This dissertation investigates sulfur based advanced electrode materials in Lithium/Sodium batteries. The electrochemical performances of the electrode materials have been enhanced due to their unique nano structures as well as the formation of novel composites. First, a nitrogen-doped graphene nanosheets/sulfur (NGNSs/S) composite was synthesized via a facile chemical reaction deposition. In this composite, NGNSs were employed as a conductive host to entrap S/polysulfides in the cathode part. The NGNSs/S composite delivered an initial discharge capacity of 856.7 mAh g-1 and a reversible capacity of 319.3 mAh g-1 at 0.1C with good recoverable rate capability. Second, NGNS/S nanocomposites, synthesized using chemical reaction-deposition method and low temperature heat treatment, were further studied as active cathode materials for room temperature Na-S batteries. Both high loading composite with 86% gamma-S8 and low loading composite with 25% gamma-S8 have been electrochemically evaluated and compared with both NGNS and S control electrodes. It was found that low loading NGNS/S composite exhibited better electrochemical performance with specific capacity of 110 and 48 mAh g-1 at 0.1C at the 1st and 300th cycle, respectively. The Coulombic efficiency of 100% was obtained at the 300th cycle. Third, high purity rock-salt (RS), zinc-blende (ZB) and wurtzite (WZ) MnS nanocrystals with different morphologies were successfully synthesized via a facile solvothermal method. RS-, ZB- and WZ-MnS electrodes showed the capacities of 232.5 mAh g-1, 287.9 mAh g-1 and 79.8 mAh g-1 at the 600th cycle, respectively. ZB-MnS displayed the best performance in terms of specific capacity and cyclability. Interestingly, MnS electrodes

  3. Polymer solution, fiber mat, and nanofiber membrane-electrode-assembly therewith, and method of fabricating same

    DEFF Research Database (Denmark)

    2016-01-01

    of fibers. The fibers may further include particles of a catalyst. The fiber mat may be used to form an electrode or a membrane. In a further aspect, a fuel cell membrane-electrode-assembly has an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode...... electrode. Each of the anode electrode, the cathode electrode and the membrane may be formed with a fiber mat....

  4. Peroxi-coagulation degradation of C.I. Basic Yellow 2 based on carbon-PTFE and carbon nanotube-PTFE electrodes as cathode

    International Nuclear Information System (INIS)

    Zarei, Mahmoud; Salari, Darioush; Niaei, Aligoli; Khataee, Alireza

    2009-01-01

    The electrochemical treatment of solutions containing C.I. Basic Yellow 2 (BY2) in aqueous solutions with carbon-PTFE (polytetrafluoroethylene) and carbon nanotube (CNT)-PTFE electrodes as cathode has been studied. The fabricated electrodes were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The amount of electrogenerated H 2 O 2 on the surface of these electrodes was investigated, too. The results showed that the amount of H 2 O 2 obtained with the CNT-PTFE electrode was nearly three times higher than that of carbon-PTFE electrode. The decolorization efficiency of BY2 in peroxi-coagulation process reached 62% and 96% in the first 10 min by carbon-PTFE and CNT-PTFE electrodes at 100 mA, respectively. The effect of operational parameters such as applied current, initial pH and initial dye concentration was studied in an attempt to reach higher decolorization efficiency. The degradation and mineralization of BY2 using CNT-PTFE electrode were followed by total organic carbon (TOC) and GC-MS analysis. The results of TOC measurements indicated that peroxi-coagulation with carbon-PTFE allowed 81% mineralization after 6 h of electrolysis; whereas peroxi-coagulation with CNT-PTFE yields 92% mineralization under the same conditions. GC-MS analysis verified the identity of intermediates and a reaction pathway based on them was proposed.

  5. Glassy carbon electrodes modified with a film of nanodiamond-graphite/chitosan: Application to the highly sensitive electrochemical determination of Azathioprine

    International Nuclear Information System (INIS)

    Shahrokhian, Saeed; Ghalkhani, Masoumeh

    2010-01-01

    A novel modified glassy carbon electrode with a film of nanodiamond-graphite/chitosan is constructed and used for the sensitive voltammetric determination of azathioprine (Aza). The surface morphology and thickness of the film modifier are characterized using atomic force microscopy. The electrochemical response characteristics of the electrode toward Aza are investigated by means of cyclic voltammetry. The modified electrode showed an efficient catalytic role for the electrochemical reduction of Aza, leading to a remarkable decrease in reduction overpotential and enhancement of the kinetics of the electrode reaction with a significant increase of peak current. The effects of experimental variables, such as the deposited amount of modifier suspension, the pH of the supporting electrolyte, the accumulation potential and time were investigated. Under optimal conditions, the modified electrode showed a wide linear response to the concentration of Aza in the range of 0.2-100 μM with a detection limit of 65 nM. The prepared modified electrode showed several advantages: simple preparation method, high stability and uniformity in the composite film, high sensitivity, excellent catalytic activity in physiological conditions and good reproducibility. The modified electrode can be successfully applied to the accurate determination of trace amounts of Aza in pharmaceutical and clinical preparations.

  6. The fabrication and characterization of an ex situ plated lead film electrode prepared with the use of a reversibly deposited mediator metal

    International Nuclear Information System (INIS)

    Tyszczuk, Katarzyna

    2011-01-01

    Research highlights: → The lead film electrode prepared with use of the mediator metal was elaborated. → The lead-based sensors were characterized by optical and voltammetric methods. → The adsorptive system of folic acid was employed to investigate a new electrode. → The application of the mediator metal improved properties of a lead film electrode. - Abstract: In this paper an ex situ plated lead film electrode prepared with use of the mediator metal (Zn) was elaborated. The electrochemical method for lead film formation is based on a co-deposition of a metal of interest (Pb) with a reversibly deposited mediator metal (Zn) and then on an oxidation of zinc and further deposition of lead by the appropriate potential. This serves to increase the density of islands of lead atoms, promoting lead film growth. The lead-based sensors were characterized by optical method (atomic force microscopy (AFM)) and as well as cyclic, linear sweep and square wave voltammetry. The adsorptive system of folic acid was employed to investigate the electrochemical characteristics a novel type of lead film electrode. Well-formed stripping peaks and a linear dependence of the stripping current on the folic acid concentration were observed on the lead film electrode prepared with use of the mediator metal while comparative measurements attempted with the lead film electrode prepared without use of the mediator metal were unsuccessful.

  7. Glassy carbon electrodes modified with a film of nanodiamond-graphite/chitosan: Application to the highly sensitive electrochemical determination of Azathioprine

    Energy Technology Data Exchange (ETDEWEB)

    Shahrokhian, Saeed, E-mail: shahrokhian@sharif.ed [Department of Chemistry, Sharif University of Technology, Tehran 11155-9516 (Iran, Islamic Republic of); Institute for Nanoscience and Technology, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Ghalkhani, Masoumeh [Department of Chemistry, Sharif University of Technology, Tehran 11155-9516 (Iran, Islamic Republic of)

    2010-04-15

    A novel modified glassy carbon electrode with a film of nanodiamond-graphite/chitosan is constructed and used for the sensitive voltammetric determination of azathioprine (Aza). The surface morphology and thickness of the film modifier are characterized using atomic force microscopy. The electrochemical response characteristics of the electrode toward Aza are investigated by means of cyclic voltammetry. The modified electrode showed an efficient catalytic role for the electrochemical reduction of Aza, leading to a remarkable decrease in reduction overpotential and enhancement of the kinetics of the electrode reaction with a significant increase of peak current. The effects of experimental variables, such as the deposited amount of modifier suspension, the pH of the supporting electrolyte, the accumulation potential and time were investigated. Under optimal conditions, the modified electrode showed a wide linear response to the concentration of Aza in the range of 0.2-100 muM with a detection limit of 65 nM. The prepared modified electrode showed several advantages: simple preparation method, high stability and uniformity in the composite film, high sensitivity, excellent catalytic activity in physiological conditions and good reproducibility. The modified electrode can be successfully applied to the accurate determination of trace amounts of Aza in pharmaceutical and clinical preparations.

  8. Graphene-based battery electrodes having continuous flow paths

    Science.gov (United States)

    Zhang, Jiguang; Xiao, Jie; Liu, Jun; Xu, Wu; Li, Xiaolin; Wang, Deyu

    2014-05-24

    Some batteries can exhibit greatly improved performance by utilizing electrodes having randomly arranged graphene nanosheets forming a network of channels defining continuous flow paths through the electrode. The network of channels can provide a diffusion pathway for the liquid electrolyte and/or for reactant gases. Metal-air batteries can benefit from such electrodes. In particular Li-air batteries show extremely high capacities, wherein the network of channels allow oxygen to diffuse through the electrode and mesopores in the electrode can store discharge products.

  9. Electronically conductive polymer binder for lithium-ion battery electrode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gao; Xun, Shidi; Battaglia, Vincent S.; Zheng, Honghe

    2017-05-16

    A family of carboxylic acid group containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  10. Added clinical value of the inferior temporal EEG electrode chain

    DEFF Research Database (Denmark)

    Bach Justesen, Anders; Eskelund Johansen, Ann Berit; Martinussen, Noomi Ida

    2018-01-01

    Objective To investigate the diagnostic added value of supplementing the 10–20 EEG array with six electrodes in the inferior temporal chain. Methods EEGs were recorded with 25 electrodes: 19 positions of the 10–20 system, and six additional electrodes in the inferior temporal chain (F9/10, T9/10, P...... in the inferior chain) and 6% (only seen at the inferior chain). Conclusions Adding six electrodes in the inferior temporal electrode chain to the 10–20 array improves the localization and identification of EEG abnormalities, especially those located in the temporal region. Significance Our results suggest...

  11. Characterization of poly(5-hydroxytryptamine)-modified glassy carbon electrode and applications to sensing of norepinephrine and uric acid in preparations and human urines

    International Nuclear Information System (INIS)

    Shi, Peiying; Miao, Xiaoqing; Yao, Hong; Lin, Sijie; Wei, Biyu; Chen, Jianji; Lin, Xinhua; Tang, Yuhai

    2013-01-01

    Graphical abstract: A 5-hydroxytryptamine (5-HT) modified electrode was fabricated by electro-polymerization of 5-HT on a glassy carbon electrode (GCE) by cyclic voltammetry (CV) in 0.05 M PBS (pH 7). The characterization of the modified electrode was carried out by atomic force microscopy (AFM), voltammetry and electrochemical impedance spectroscopy (EIS). The mechanism of electro-deposition of 5-HT at GCE was discussed based on electrochemical studies and quantum chemical calculations. The poly(5-HT)-modified electrode could separately detect NE and UA, even in the presence of 10-fold concentration of ascorbic acid (AA) and was applied successfully to the analysis of NE preparations and healthy human urines. Due to the favorable functionalized groups (-NH 2 and -OH), electroactivity, biocompatibility and stability, the poly(5-HT) film could be a promising immobilization matrix for anchoring interested biological molecules in the fabrication of sensors and biosensors. Highlights: ► A poly(5-HT)-modified electrode was fabricated originally by CV. ► The electro-deposition mechanism of 5-HT at GCE was proposed. ► The polymer film shows favorable electrocatalytic properties to NE and UA. ► The modified GCE was applied to the sensing analysis of real samples. -- Abstract: A poly(5-hydroxytryptamine) (poly(5-HT)) modified electrode was fabricated by electropolymerization of 5-hydroxytryptamine (5-HT) on a glassy carbon electrode (GCE) by cyclic voltammetry (CV) in 0.05 M PBS (pH 7). The characterization of poly(5-HT)-modified electrode was carried out by atomic force microscopy (AFM), voltammetry and electrochemical impedance spectroscopy (EIS). Results showed that a brown and heterogeneous film was formed on the surface of the modified electrode. The mechanism of electro-deposition of 5-HT at GCE was discussed. The modified electrode showed good affinity and electrocatalytic properties to some species, such as norepinephrine (NE) and uric acid (UA). Furthermore

  12. Light-addressable amperometric electrodes for enzyme sensors based on direct quantum dot-electrode contacts

    Science.gov (United States)

    Riedel, M.; Göbel, G.; Parak, W. J.; Lisdat, F.

    2014-03-01

    Quantum dots allow the generation of charge carriers upon illumination. When these particles are attached to an electrode a photocurrent can be generated. This allows their use as a light-switchable layer on the surface. The QDs can not only exchange electronics with the electrode, but can also interact with donor or acceptor compounds in solution providing access to the construction of signal chains starting from an analytic molecule. The magnitude and the direction of the photocurrent depend on several factors such as electrode polarization, solution pH and composition. These defined dependencies have been evaluated with respect to the combination of QD-electrodes with enzyme reactions for sensorial purpose. CdSe/ZnS-QD-modified electrodes can be used to follow enzymatic reactions in solution based on the oxygen sensitivity. In order to develop a photoelectrochemical biosensor, e.g. glucose oxidase is immobilized on the CdSe/ZnS-electrode. One immobilization strategy applies the layer-by-layer-technique of GOD and a polyelectrolyte. Photocurrent measurements of such a sensor show a clear concentration dependent behavior. The principle of combing QD oxidase. The sensitivity of quantum dot electrodes can be influenced by additional nanoparticles, but also by multiple layers of the QDs. In another direction of research it can be influenced by additional nanoparticles, but also by multiple layers of the QDs. In another direction of research it can be demonstrated that direct electron transfer from excited quantum dots can be achieved with the redox protein cytochrome c. This allows the detection of the protein, but also interaction partners such as a enzymes or superoxide.

  13. Preparation and characterization of core-shell electrodes for application in gel electrolyte-based dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Avellaneda, Cesar O.; Goncalves, Agnaldo D.; Benedetti, Joao E.; Nogueira, Ana F.

    2010-01-01

    Core-shell electrodes based on TiO 2 covered with different oxides were prepared and characterized. These electrodes were applied in gel electrolyte-based dye-sensitized solar cells (DSSC). The TiO 2 electrodes were prepared from TiO 2 powder (P25 Degussa) and coated with thin layers of Al 2 O 3 , MgO, Nb 2 O 5 , and SrTiO 3 prepared by the sol-gel method. The core-shell electrodes were characterized by X-ray diffraction, scanning electron microscopy and atomic force microscopy measurements. J-V curves in the dark and under standard AM 1.5 conditions and photovoltage decay measurements under open-circuit conditions were carried out in order to evaluate the influence of the oxide layer on the charge recombination dynamics and on the device's performance. The results indicated an improvement in the conversion efficiency as a result of an increase in the open circuit voltage. The photovoltage decay curves under open-circuit conditions showed that the core-shell electrodes provide longer electron lifetime values compared to uncoated TiO 2 electrodes, corroborating with a minimization in the recombination losses at the nanoparticle surface/electrolyte interface. This is the first time that a study has been applied to DSSC based on gel polymer electrolyte. The optimum performance was achieved by solar cells based on TiO 2 /MgO core-shell electrodes: fill factor of ∼0.60, short-circuit current density J sc of 12 mA cm -2 , open-circuit voltage V oc of 0.78 V and overall energy conversion efficiency of ∼5% (under illumination of 100 mW cm -2 ).

  14. A study of effects of electrode contacts on performance of organic-based light-emitting field-effect transistors

    Science.gov (United States)

    Kim, Dae-Kyu; Choi, Jong-Ho

    2018-02-01

    Herein is presented a comparative performance analysis of heterojunction organic-based light-emitting field-effect transistors (OLEFETs) with symmetric (Au only) and asymmetric (Au and LiF/Al) electrode contacts. The devices had a top source-drain contact with long-channel geometry and were produced by sequentially depositing p-type pentacene and n-type N,N‧-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (P13) using a neutral cluster beam deposition apparatus. The spectroscopic, structural and morphological properties of the organic thin films were examined using photoluminescence (PL) spectroscopy, X-ray diffraction (XRD) method, laser scanning confocal and atomic force microscopy (LSCM, AFM). Based upon the growth of high-quality, well-packed crystalline thin films, the devices demonstrated ambipolar field-effect characteristics, stress-free operational stability, and light emission under ambient conditions. Various device parameters were derived from the fits of the observed characteristics. The hole mobilities were nearly equal irrespective of the electrode contacts, whereas the electron mobilities of the transistors with LiF/Al drain electrodes were higher due to the low injection barrier. For the OLEFETs with symmetric electrodes, electroluminescence (EL) occurred only in the vicinity of the hole-injecting electrode, whereas for the OLEFETs with asymmetric electrodes, the emission occurred in the vicinity of both hole- and electron-injecting electrodes. By tuning the carrier injection and transport through high- and low-work function metals, the hole-electron recombination sites could be controlled. The operating conduction and light emission mechanism are discussed with the aid of EL images obtained using a charge-coupled device (CCD) camera.

  15. Graphene nanocomposites for electrochemical cell electrodes

    Science.gov (United States)

    Zhamu, Aruna; Jang, Bor Z.; Shi, Jinjun

    2015-11-19

    A composite composition for electrochemical cell electrode applications, the composition comprising multiple solid particles, wherein (a) a solid particle is composed of graphene platelets dispersed in or bonded by a first matrix or binder material, wherein the graphene platelets are not obtained from graphitization of the first binder or matrix material; (b) the graphene platelets have a length or width in the range of 10 nm to 10 .mu.m; (c) the multiple solid particles are bonded by a second binder material; and (d) the first or second binder material is selected from a polymer, polymeric carbon, amorphous carbon, metal, glass, ceramic, oxide, organic material, or a combination thereof. For a lithium ion battery anode application, the first binder or matrix material is preferably amorphous carbon or polymeric carbon. Such a composite composition provides a high anode capacity and good cycling response. For a supercapacitor electrode application, the solid particles preferably have meso-scale pores therein to accommodate electrolyte.

  16. The heating of plasma focus electrodes

    International Nuclear Information System (INIS)

    Angeli, E; Frignani, M; Mannucci, S; Rocchi, F; Sumini, M; Tartari, A

    2006-01-01

    Plasma focus (PF) technology development today is strictly related to the possibility of a high frequency repetitive working regime. One of the more relevant obstacles to this goal is the heating of structural components due to direct interaction with plasma. In this paper, temperature decay measurements of the inner electrode of a 7 kJ Mather type PF are presented. Data from several series of shots at different bank energies are analysed and compared with theoretical and numerical models. Two possible scale laws are derived from the experimental data to correlate thermal deposition with bank energy. It is found that a fraction of about 10% of total energy is released to the inner electrode. Finally, after some considerations about the cooling and heating mechanisms, an analysis on maximum temperature sustained by materials is presented

  17. Quantitative Microstructure Characterization of a NMC Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Usseglio-Viretta, François Laurent Emilien; Smith, Kandler

    2017-07-07

    Performance of lithium-ion batteries (LIBs) is strongly influenced by the porous microstructure of their electrodes. In this work, 3D microstructures of calendared and un-calendared positive electrode LiNi1/3Mn1/3Co1/3O2 (NMC) have been investigated in order to extract relevant properties useful for battery modeling. Transport (volume fraction, connectivity, particle size and tortuosity) and electrochemical (specific surface area) properties have been calculated for the pore and the active material. Special attention has been paid to determine the size of the so-called representative volume element (RVE) required to be statistically representative of the heterogeneous medium. Several parameters have been calculated using a panel of different numerical methods in order to compare their results. Besides, the image level of detail has been evaluated (using original criteria based upon edge detection) to assess the overall data quality available for the study.

  18. Quantitative Microstructure Characterization of a NMC Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Usseglio Viretta, Francois L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Smith, Kandler A [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-28

    Performance of lithium-ion batteries (LIBs) is strongly influenced by the porous microstructure of their electrodes. In this work, 3D microstructures of calendared and un-calendared positive electrode LiNi1/3Mn1/3Co1/3O2 (NMC) have been investigated in order to extract relevant properties useful for battery modeling. Transport (volume fraction, connectivity, particle size and tortuosity) and electrochemical (specific surface area) properties have been calculated for the pore and the active material. Special attention has been paid to determine the size of the so-called representative volume element (RVE) required to be statistically representative of the heterogeneous medium. Several parameters have been calculated using a panel of different numerical methods in order to compare their results. Besides, the image level of detail has been evaluated (using original criteria based upon edge detection) to assess the overall data quality available for the study.

  19. Tailored ion energy distributions on plasma electrodes

    International Nuclear Information System (INIS)

    Economou, Demetre J.

    2013-01-01

    As microelectronic device features continue to shrink approaching atomic dimensions, control of the ion energy distribution on the substrate during plasma etching and deposition becomes increasingly critical. The ion energy should be high enough to drive ion-assisted etching, but not too high to cause substrate damage or loss of selectivity. In many cases, a nearly monoenergetic ion energy distribution (IED) is desired to achieve highly selective etching. In this work, the author briefly reviews: (1) the fundamentals of development of the ion energy distribution in the sheath and (2) methods to control the IED on plasma electrodes. Such methods include the application of “tailored” voltage waveforms on an electrode in continuous wave plasmas, or the application of synchronous bias on a “boundary electrode” during a specified time window in the afterglow of pulsed plasmas

  20. Al nanogrid electrode for ultraviolet detectors.

    Science.gov (United States)

    Ding, G; Deng, J; Zhou, L; Gan, Q; Hwang, J C M; Dierolf, V; Bartoli, F J; Mazuir, C; Schoenfeld, W V

    2011-09-15

    Optical properties of Al nanogrids of different pitches and gaps were investigated both theoretically and experimentally. Three-dimensional finite-difference time-domain simulation predicted that surface plasmons at the air/Al interface would enhance ultraviolet transmission through the subwavelength gaps of the nanogrid, making it an effective electrode on GaN-based photodetectors to compensate for the lack of transparent electrode and high p-type doping. The predicted transmission enhancement was verified by confocal scanning optical microscopy performed at 365 nm. The quality of the nanogrids fabricated by electron-beam lithography was verified by near-field scanning optical microscopy and scanning electron microscopy. Based on the results, the pitch and gap of the nanogrids can be optimized for the best trade-off between electrical conductivity and optical transmission at different wavelengths. Based on different cutoff wavelengths, the nanogrids can also double as a filter to render photodetectors solar-blind.